3 day malaria. Malaria: causes, symptoms, diagnosis, treatment and prevention. Malaria in pregnant women

Accompanied by fever, chills, an increase in the size of the spleen and liver, and anemia. A characteristic feature of this protozoal invasion is the cyclical clinical course, i.e. periods of improved well-being are followed by periods of sharp deterioration with a high rise in temperature.

The disease is most common in countries with hot climates. These are South America, Asia and Africa. According to the World Health Organization, malaria is a serious health problem in 82 countries where the mortality rate from this infection is very high.

The relevance of malaria for Russian people is due to the possibility of infection during tourist trips. Often the first symptoms appear upon arrival home, when a person’s temperature rises.

It is imperative that if this symptom appears, you should inform your doctor about your trip, because this will make it easier to establish the correct diagnosis and save time.

Causes, clinical picture of the disease

The causative agent of malaria is Plasmodium falciparum. It belongs to the class of protozoa. The causative agents can be 4 types of plasmodia (although there are more than 60 species in nature):

• P. Malariae – leads to malaria with a 4-day cycle;
• P.vivax – causes malaria with a 3-day cycle;
• P. Falciparum – causes tropical malaria;
• R. Ovale - causes the oval form of tertian malaria.

The life cycle of malarial plasmodia includes a successive change of several stages. At the same time, a change of owners occurs. At the stage of schizogony, pathogens are found in the human body. This is the stage of asexual development, it is replaced by the sporogony stage.

It is characterized by sexual development and occurs in the body of a female mosquito, which is the carrier of the infection. The causative mosquitoes belong to the genus Anopheles.

Penetration of malarial plasmodia into the human body can occur at different stages in different ways:

1. When bitten by a mosquito, infection occurs at the sporozontal stage. Penetrated plasmodia after 15-45 minutes end up in the liver, where their intensive reproduction begins.
2. Penetration of plasmodiums of the erythrocyte cycle at the schizont stage occurs directly into the blood, bypassing the liver. This route is realized when donated blood is administered or when using non-sterile syringes that can be contaminated with plasmodia. At this stage of development, it passes from mother to child in utero (vertical route of infection). This is the danger of malaria for pregnant women.

In typical cases, division of plasmodia that enter the body through a mosquito bite occurs in the liver. Their number is increasing many times over. At this time, there are no clinical manifestations (incubation period).

The duration of this stage varies depending on the type of pathogen. It is minimal in P. falciparum (from 6 to 8 days) and maximum in P. malariae (14-16 days).

The characteristic symptoms of malaria are described by the well-known triad:

• paroxysmal (crisis-type) increase in temperature, repeated at certain intervals (3 or 4 days);
• enlargement of the liver and spleen (hepatomegaly and splenomegaly, respectively);
• anemia.

The first symptoms of malaria are nonspecific. They correspond to the prodromal period and are manifested by signs characteristic of any infectious process:

• general malaise;
• severe weakness;
• lower back pain;
• joint and muscle pain;
• slight increase in temperature;
• decreased appetite;
• dizziness;
• headache.

A specific increase in temperature develops due to the release of plasmodium into the blood. This process is repeated several times, reflected in the temperature curve. The cycling time is different - in some cases it is 3 days, and in others - 4.

Based on this, the corresponding types of malaria are distinguished (three-day and four-day). This is the period of obvious clinical manifestations when the patient consults a doctor.

Fever in malaria has a characteristic appearance, due to the sequential change of three phases. At the beginning there is a stage of chills (a person cannot warm up, despite warm wrappings), which is replaced by fever (the second stage). The temperature rises to high values ​​(40-41°C).

The attack ends with excessive sweating. It usually lasts from 6 to 10 hours. After an attack, a person immediately falls asleep due to severe weakening that develops as a result of intoxication and muscle contractions.

Enlargement of the liver and spleen is not determined from the very beginning of the disease. These symptoms can be identified after 2-3 febrile attacks. Their appearance is due to the active reproduction of malarial plasmodia in the liver and spleen.

When infected, anemia immediately appears in the blood, associated with the destruction of red blood cells (malarial plasmodia settle in them).

At the same time, the level of leukocytes, mainly neutrophils, decreases. Other hematological signs are an acceleration of ESR, a complete absence of eosinophils and a relative increase in lymphocytes.

These signs indicate activation of the immune system. She fights the infection, but fails. The disease progresses, and the risk of complications increases.

With a certain degree of probability, they can be predicted based on unfavorable prognostic signs. These are considered:

• fever that occurs every day, and not cyclically (every 3-4 days);
• absence of an interfebrile period between attacks (an elevated temperature is constantly determined, which corresponds to subfebrile values ​​between attacks);
• severe headache;
• widespread convulsions observed 24-48 hours after the next attack;
• a critical decrease in blood pressure (70/50 mm Hg or less), approaching a state of shock;
• high level of protozoa in the blood according to microscopic examination;
• the presence of plasmodia in the blood, which are at different stages of development;
• progressive increase in the number of leukocytes;
• decrease in glucose below 2.1 mmol/l.

Main complications malaria are:

• malarial coma, which most often affects pregnant women, children and young people;
• acute kidney failure when diuresis decreases to less than 400 ml per day;
• hemoglobinuric fever, which develops with massive intravascular destruction of red blood cells and the formation of a large amount of toxic substances;
• malarial algid, which resembles brain damage in this disease, but differs from it in the preservation of consciousness;
• pulmonary edema with acute onset and course (often fatal);
• rupture of the spleen associated with torsion of its legs or congestion;
• severe anemia caused by hemolysis;
• intravascular coagulation as part of DIC syndrome, followed by pathological bleeding.

Complications of tropical malaria may be specific:

• corneal damage;
• vitreous opacification;
• choroiditis (inflammatory damage to the capillaries of the eye);
• optic neuritis;
• paralysis of the eye muscles.

Laboratory diagnosis of malaria is carried out according to indications. These include:

1) Any increase in body temperature in a person located in an endemic geographic area (countries with increased incidence).

2) Increased temperature in a person who has received a blood transfusion within the last 3 months.

3) Repeated episodes of fever in a person receiving therapy in accordance with the final diagnosis (established diagnosis is any disease other than malaria).

4) Fever persists for 3 days during the epidemic period and more than 5 days at other times.

5) The presence of certain symptoms (one or more) in people who have visited endemic countries within the last 3 years:

• fever;
• malaise;
• chills;
• liver enlargement;
• headache;
• enlarged spleen;
• decrease in hemoglobin;
• yellowness of the skin and mucous membranes;
• the presence of herpetic rashes.

To verify the diagnosis, various laboratory examination methods can be used:

1. Microscopic examination of blood smears (allows direct detection of malarial plasmodium).
2. Express test.
3. (the study of genetic material by repeatedly obtaining copies of the DNA of the malarial plasmodium when it is present in the blood).
4. A biochemical analysis is performed to determine the severity of the disease (determines the severity of liver damage, which is always observed with malaria).

All patients with a confirmed diagnosis of malaria are recommended to undergo a number of instrumental studies. Their results help the doctor identify possible complications and begin their treatment in time.

• ultrasound scanning of the abdominal cavity (particular attention is paid to the size of the liver, kidneys and spleen);
• electrocardiogram;
• X-ray of the lungs;
• echocardioscopy;
• neurosonography;
• electroencephalography.

Treatment of patients with malaria is carried out only in a hospital. The main goals of therapy are:

• prevention and elimination of acute attacks of the disease;
• prevention of complications and their timely correction;
• prevention of relapse and carriage of malarial plasmodia.

Immediately after diagnosis, all patients are recommended to undergo bed rest and be prescribed antimalarial drugs. These include:

• Primaquine;
• Chloroquine;
• Mefloquine;
• Pyrimethamine and others.

At the same time, the use of antipyretic and symptomatic drugs is indicated. They are quite diverse due to the multiorgan nature of the lesion. Therefore, doctors of various specialties are often involved in treatment, and not just infectious disease specialists.

In cases where this does not happen, a change in antimalarial drug is required. It is also indicated when plasmodia are detected in the blood on the 4th day. This may indicate possible pharmacological resistance. It increases the risk of distant relapses.
If everything goes smoothly, then special criteria are determined to finally confirm cure. These include:

• normalization of temperature;
• reduction of the spleen and liver to normal sizes;
• a normal blood picture - the absence of asexual stages of malarial plasmodia in it;
• normal biochemical blood test values, indicating restoration of liver function.

Prevention of malaria

Map of malaria distribution in the world

Tourists should pay close attention to malaria prevention. Even before traveling, you should find out from a travel agency whether the country poses a danger for this disease.

If yes, then you should visit an infectious disease specialist in advance. He will recommend taking antimalarial drugs that will protect the person from infection.

There is no specific vaccine against malaria.

• Avoid being on the street after 17.00, because this is the time when mosquito activity peaks;
• If you need to go outside, cover your body with clothes. Pay special attention to the ankles, where mosquitoes most often bite, as well as the wrists and hands, where the skin is very thin;
• use of repellents.

If the child is small, then parents should refrain from traveling to dangerous countries. In childhood, taking antimalarial drugs is not advisable due to the frequent development of side effects and hepatotoxicity. Therefore, parents should weigh the possible risks.

World Malaria Day

The World Health Organization established International Malaria Day in 2007 (at its 60th session). It falls on April 25th.

The prerequisite for the establishment of the date was disappointing statistical data. Thus, new infections occur annually in 350–500 million cases. Of these, death occurs in 1-3 million people.

The main objective of World Malaria Day is to promote preventive measures against the disease.

Malaria is an acute febrile disease. In a person who is not immune, symptoms usually appear 10 to 15 days after being bitten by an infected mosquito. The first symptoms—fever, headache, and chills—may be mild, making malaria difficult to detect. If treatment is not started within the first 24 hours, malaria P. falciparum can develop into a serious illness, often ending in death.

Children with severe malaria often develop one or more of the following symptoms: severe anemia, respiratory failure due to metabolic acidosis, or cerebral malaria. Adults also often experience multiple organ failure. In areas where malaria is endemic, people may develop partial immunity, in which infections occur without symptoms.

Who is at risk?

In 2018, nearly half the world's population was at risk of malaria. Most malaria cases and deaths occur in sub-Saharan Africa. However, WHO regions such as South-East Asia, the Eastern Mediterranean, the Western Pacific and the Americas are also at risk.

The risk of contracting malaria and developing severe disease is significantly higher among some groups of the population. These groups include infants, children under five years of age, pregnant women and people with HIV/AIDS, as well as non-immune migrants, mobile populations and travelers. National malaria control programs need to take special measures to protect these populations from malaria infection, taking into account their specific circumstances.

Burden of disease

According to the latest edition released in December 2019, 228 million people worldwide fell ill with malaria in 2018, up from 231 million in 2017. That year, an estimated 405,000 people died from malaria, up from 461,000 people in 2017

The WHO African Region continues to bear a disproportionate share of the global malaria burden. In 2018, the region accounted for 93% of malaria cases and 94% of malaria deaths.

In 2018, more than half of all malaria cases in the world occurred in six countries: Nigeria (25%), Democratic Republic of the Congo (12%), Uganda (5%), Ivory Coast, Mozambique and Niger (4% each). every).

Children under five years of age are especially susceptible to malaria; in 2018 they accounted for 67% (272,000) of all malaria deaths worldwide.

• - in English

Transmission of infection

Mosquitoes Anopheles They lay eggs in the water and hatch into larvae that eventually develop into adult mosquitoes. Female mosquitoes need blood to lay eggs. Every type of mosquito Anopheles has its own aquatic habitat; some, for example, prefer small, shallow accumulations of fresh water, such as puddles and hoof marks, which are abundant during the rainy season in tropical countries.

Transmission of infection also depends on climate features, such as rainfall patterns, temperature and humidity, which also affect the number and survival of mosquitoes. In many places, transmission is seasonal and peaks during and immediately after the monsoon seasons. Malaria epidemics can occur when climatic and other conditions suddenly become favorable for transmission in areas where people have little or no immunity to malaria. In addition, epidemics can occur when people with weak immune systems enter areas with intense malaria transmission, for example to seek work or as refugees.

Another important factor is human immunity, especially among adults in areas with moderate to intense transmission. Partial immunity develops over several years of exposure, and although it never provides complete protection, it reduces the risk of developing severe illness in the event of a malaria infection. For this reason, most malaria deaths in Africa occur among young children, while in areas with less intense transmission and low immunity, all age groups are at risk.

Prevention

The main way to prevent and reduce malaria transmission is vector control. Sufficiently high coverage of a particular area with vector control measures provides some protection from infection to the entire population of the area.

To protect all people at risk of malaria, WHO recommends effective vector control measures. To do this, two methods can be effectively used in a wide variety of conditions - insecticide-treated mosquito nets and spraying residual insecticides indoors.

Insecticide treated mosquito nets

The use of insecticide-treated mosquito nets (ITNs) during sleep may reduce the likelihood of mosquito-human contact through both the presence of a physical barrier and exposure to the insecticide. Mass eradication of mosquitoes in areas where such nets are widely available and actively used by local residents can provide protection to the entire population.

Insecticide-treated nets in Africa protected about half of all people at risk of malaria in 2018, up from 29% in 2010. However, ITN coverage has shown little growth since 2016.

Spraying residual insecticides indoors

Another effective way to rapidly reduce malaria transmission is indoor residual spraying (IRID). Insecticide spraying inside residential areas is carried out once or twice a year. To achieve effective protection of the population, a high level of RIODVP coverage must be ensured.

Globally, the rate of use of RADI for protection has decreased from a peak of 5% in 2010 to 2% in 2018 in all WHO regions except the Eastern Mediterranean Region. The decline in MRV coverage occurs as countries shift from using pyrethroid pesticides to more expensive alternatives to address pyrethroid resistance in mosquitoes.

Antimalarial drugs

Antimalarial drugs can also be used to prevent malaria. Prevention of malaria among travelers can be achieved through chemoprophylaxis, which suppresses the blood stage of malaria infection, thereby preventing the disease from developing. Among pregnant women living in areas of moderate to intense transmission, WHO recommends intermittent sulfadoxine-pyrimethamine preventive therapy at every routine antenatal visit after the first trimester of pregnancy. Similarly, intermittent preventive therapy with three doses of sulfadoxine-pyrimethamine as part of routine vaccination is recommended for infants living in areas of Africa with high transmission rates.

Since 2012, WHO has recommended seasonal malaria chemoprophylaxis in areas of the Sahel subregion as an additional malaria prevention strategy. This strategy involves administering monthly courses of amodiaquine plus sulfadoxine-pyrimethamine to all children under five years of age during the high transmission season.

Insecticide resistance

Since 2000, progress in malaria control has been achieved largely through increased coverage of vector control interventions, particularly in sub-Saharan Africa. However, these achievements are under threat due to the increasing resistance of mosquitoes Anopheles to insecticides. According to the latest edition, between 2010 and 2018, cases of mosquito resistance to at least one of the four most common classes of insecticides were reported in 72 countries. In 27 countries, mosquito resistance to all major classes of insecticides was observed.

Despite the rise and spread of mosquito resistance to pyrethroids, insecticide-treated nets continue to provide significant levels of protection in most areas of human activity. This was confirmed by the results

Despite the encouraging results of this study, WHO continues to reiterate the urgent need for new and improved tools to combat malaria worldwide. WHO also emphasizes the urgent need for all countries where malaria transmission continues to develop and implement effective strategies to combat insecticide resistance to prevent the decline in the effectiveness of the most common vector control tools.

Diagnosis and treatment

Early diagnosis and treatment of malaria helps reduce the severity of the disease and prevent death. These measures also help reduce the intensity of malaria transmission. The most effective treatment regimen available, especially for malaria P. falciparum, is artemisinin combination therapy (ACT).

Ensuring the effectiveness of antimalarial drugs is critical to malaria control and elimination. Regular monitoring of drug effectiveness is required to develop treatment strategies for malaria-endemic countries and to ensure timely detection and control of drug resistance.

At the World Health Assembly in May 2015, WHO adopted, which was endorsed by all countries in the subregion. The strategy aims to eliminate all types of human malaria across the region by 2030 and includes a series of immediate actions, particularly in areas where multidrug-resistant malaria is widespread.

All countries in the subregion, with technical support from WHO, have developed national malaria elimination plans. WHO, together with partners, is providing ongoing support to countries' efforts to eliminate malaria through the Mekong Malaria Elimination Programme, a new initiative that is a continuation of the EMER.

Surveillance

Surveillance involves monitoring cases of disease, systematically responding, and making decisions based on the findings. Currently, many countries with a high malaria burden have weak surveillance systems and are unable to assess the distribution and trends of the disease, making it difficult to optimize responses and respond to outbreaks.

Effective surveillance is needed at all stages of the progress towards malaria elimination. Strengthening malaria surveillance programs is urgently needed to ensure a timely and effective response to malaria in endemic regions, prevent outbreaks and re-emergence of the disease, monitor progress and hold governments and other global actors in the fight against malaria accountable.

In March 2018, WHO released . The guide provides information on global surveillance standards and recommendations for strengthening country surveillance systems.

Elimination

Elimination is expanding around the world, and more countries are moving closer to the goal of reducing malaria incidence to zero. In 2018, the number of countries reporting fewer than 100 cases of local transmission was 27, up from 17 in 2010.

Countries that have not reported a local case of malaria for at least three consecutive years meet the criteria for submitting an application to WHO. In recent years, 10 countries have been certified as malaria-free by the WHO Director General: Morocco (2010), Turkmenistan (2010), Armenia (2011), Maldives (2015), Sri Lanka (2016) .), Kyrgyzstan (2016), Paraguay (2018), Uzbekistan (2018), Algeria (2019) and Argentina (2018). Accepted by WHO Malaria Elimination Framework(2017) provides a comprehensive set of tools and strategies to achieve and maintain elimination.

Vaccines against malaria

Leading WHO advisory bodies on malaria and immunization, given the high public health importance of this vaccine, have jointly recommended its phased introduction in parts of sub-Saharan Africa. In 2019, three countries (Ghana, Kenya and Malawi) began introducing the vaccine in selected areas with moderate to high intensity malaria transmission. Vaccination is carried out as part of the national routine immunization program of each country.

The vaccine pilot program will provide answers to a number of outstanding questions regarding its use in public health. This will be important in understanding the optimal administration schedule for the four recommended doses of RTS,S; the potential role of vaccines in reducing child mortality; and its safety during routine vaccinations.

The program is being coordinated by WHO, together with the ministries of health of Ghana, Kenya and Malawi, as well as a number of national and international partners, including the non-profit organization PATH and GlaxoSmithKline (GSK), the vaccine developer and manufacturer.

Funding for the vaccine development program was provided through a collaboration between three of the world's largest health financing organizations: the Vaccine Alliance GAVI, the Global Fund to Fight AIDS, Tuberculosis and Malaria and UNITAID.

WHO activities

WHO global technical strategy for malaria control 2016–2030.

Adopted by the World Health Assembly in May 2015. sets technical parameters for work in all malaria-endemic countries. It aims to guide and support regional and national programs as they work to control and achieve malaria elimination.

This strategy sets ambitious but achievable global goals, including:

• reducing the incidence of malaria by at least 90% by 2030;
• reducing malaria mortality rates by at least 90% by 2030;
• eliminating malaria in at least 35 countries by 2030;
• preventing the re-emergence of malaria in all malaria-free countries.

The strategy was the result of a broad consultative process over two years involving more than 400 technical experts from 70 Member States.

Global Malaria Program

Ensures coordination of WHO's international efforts to control malaria and achieve its elimination through:

• developing, communicating and promoting their adoption of norms, standards, policies, technical strategies and guidelines;
• independent assessment of global progress;
• developing approaches to strengthen capacity, improve systems and conduct surveillance;
• identifying factors that threaten effective malaria control and elimination, as well as finding new areas of action.

The Program is supported and advised by a Malaria Policy Advisory Committee (MPAC), composed of malaria experts appointed through open nominations. The mandate of the ACPM is to provide policy advice and technical advice on all aspects of malaria control and elimination through a transparent, flexible and credible rule-making process.

"A heavy burden requires high efficiency"

At the World Health Assembly in May 2018, WHO Director-General Dr Tedros Adhanom Ghebreyesus called for a new proactive approach to accelerate progress in the fight against malaria. A new initiative, carried out with the active participation of countries, was launched in November 2018 in Mozambique.

Currently, 11 countries with the highest burden of disease are participating (Burkina Faso, Cameroon, Democratic Republic of the Congo, Ghana, India, Mali, Mozambique, Niger, Nigeria, Uganda and the United Republic of Tanzania). The main elements of the initiative are:

• mobilizing political will to reduce the burden of malaria;
• providing strategic information to achieve real change;
• improving guidelines, policies and strategies;
• coordinated efforts to combat malaria at the national level.

The High Burden Means High Impact initiative, carried out with the active participation of WHO and the WOM Partnership to End Malaria, is based on the principle that no one should die from a disease that is preventable and diagnosable and completely curable with existing medicines.

Malaria is a serious disease that can sometimes be fatal. People who become infected with it usually experience severe symptoms, including chills, fever, and flu-like symptoms. Malaria disease has a high probability of death. However, timely and correct treatment can prevent this. The causative agent of malaria is Plasmodium, which lives in the body of a certain organism and feeds on human blood. This issue will be discussed in more detail below. You will find information about the treatment and prevention of the disease in this publication.

Story

The symptoms of malaria have been described in ancient Chinese medical writings. Several characteristic signs of the disease, which was later called malaria, are found in the work of the imperial doctor Nei Jing, “The Canons of Medicine.” This disease was widely known in Greece already in the 4th century BC, at that time it caused high mortality rates. The main symptoms were noted by Hippocrates and other philosophers and doctors of antiquity. The Hindu physician Susruta, a thinker and adherent of Ayurveda, also mentioned in his treatise the symptoms of malaria and talked about their appearance after the bites of certain insects. Some Roman writers associated malaria with swamps.

The inquisitive minds of mankind have always looked for ways to cure all kinds of ailments. What methods were resorted to for the treatment of malaria in ancient times: bloodletting, amputation of a bitten limb, the use of opiates... Even astrologers were involved, who connected the frequency of occurrence of malarial fevers with astronomical phenomena and the position of stars in the sky. Many turned to witchcraft. Scientist Albert Magnus, a Dominican, proposed treating malaria by eating small buns made from flour and the urine of a sick person, as well as drinking a drink that included cognac, the blood of the infected person and pepper.

The ancient Greek physician Galen, who worked in Rome, suggested that vomiting, which occurs with malaria, is an attempt by the body to expel poisons, and bloodletting speeds up healing. These principles dominated medicine for fifteen hundred years. Countless malaria patients were subjected to bloodletting and forced cleansing of the stomach and intestines through enemas and vomiting. This had disastrous results: people died from anemia and dehydration, as well as the devastating symptoms of malaria, in an even shorter time.

In China in the 2nd century BC. In the works of doctors, the plant artemisia, or sweet wormwood, was described, which was used as a remedy for malaria. Interestingly, in 1971, Chinese scientists isolated the active ingredient from it - artemisin. During the Vietnam War, active work was carried out to study the antimalarial properties of sweet wormwood. The plant extract was fed to laboratory mice and rats infected with strains of malaria. Artemisinin has proven to be quite effective, as have quinine and chloroquine. Derivatives of this substance are now part of powerful and effective antimalarial drugs.

The type of plasmodium that causes malaria was first discovered by the French physician and scientist Laveran at the end of the 19th century. Russian researchers made a huge contribution to the study of the disease and the development of methods for its elimination. Among these scientists it is worth noting E.I. Martsinovsky, V.A. Danilevsky, S.P. Botkin. During the First and Second World Wars, there were spikes in the incidence of malaria.

Signs

Malaria is a disease whose symptoms include chills, fever, headaches and muscle pain. Some patients experience nausea, vomiting, cough and diarrhea. The fever condition recurs every one, two or three days - this is the most typical manifestation of malaria. Shivering and a feeling of cold are replaced by the so-called hot stage, which is characterized by high fever, cramps, headaches and vomiting.

Complications are often signs of a form of the disease such as tropical malaria. Due to the destruction of red blood cells and liver cells, jaundice of the skin and whites of the eyes, as well as diarrhea and cough, may occur. In more rare cases, a rash appears on the body in the form of itchy reddish papules. Malaria is determined by these signs. A photo of the carrier of the disease is presented above.

Severe forms, for example, if the causative agent of malaria is Plasmodium falciparum, are accompanied by problems such as:

• bleeding;
• liver and kidney failure;
• shock and coma;
• damage to the central nervous system.

Without timely treatment, these symptoms often lead to death.

How is it transmitted?

Sporozoites (immature plasmodia) travel through the human bloodstream and enter the liver. There they mature and infect red blood cells - erythrocytes, inside which they develop until the patient is again bitten by the malaria carrier - the mosquito. Once in the body of an insect, plasmodia penetrate its salivary glands, and with the next bite, in the form of sporozoites, they again begin their life cycle in the human blood.

The developmental processes of species such as P. ovale and P. vivax can be even more complex and involve the formation of inactive forms, hypnozoites, which often remain inactive for weeks or even years. In the body of the malaria mosquito, plasmodia go through the sexual period of their life cycle, and in the human body the pathogen remains in an asexual phase, which is also called schizogony. Therefore, the development cycle of Plasmodium in red blood cells is called erythrocyte schizogony.

How is the infection transmitted? Its sources are female malaria mosquitoes and an infected person (both the patient and the carrier). It is worth noting that malaria is a disease that is not transmitted among people either through household or airborne transmission. Infection can only occur if the blood of a sick person enters the body of a healthy person.

Diagnostic features

If the above symptoms appear, especially after travel, it is recommended to be tested for the presence of malarial plasmodium. The symptoms of many diseases can resemble those of malaria. These are, for example, typhoid fever, influenza, cholera, measles and tuberculosis. Therefore, the doctor must know the travel history of the sick person in order to prescribe the necessary tests.

Other tests that can help diagnose the disease:

• immunological tests;
• polymerase chain reaction.

Treatment

Features of therapy depend on several factors:

• the type of plasmodium that has entered the body;
• the clinical situation of the patient, for example, treatment will be different for an adult, a child and a pregnant woman, for severe and mild forms of the disease;
• drug sensitivity of the pathogen.

The last factor depends on the geographic area in which the infection was acquired. The fact is that different areas of the world have different types of malarial plasmodia that are resistant to certain drugs. Anti-malaria medications can be selected correctly by a doctor who is familiar with information from malaria treatment protocols around the world. People infected with P. falciparum may die without timely treatment, so therapeutic measures must be taken immediately.

Mild forms of malaria are treated with oral medications. Complex symptoms such as severe anemia, impaired consciousness, coma, pulmonary edema, renal failure, acute respiratory syndrome, disseminated intravascular coagulation, spontaneous bleeding, acidosis, hemoglobin in the urine, jaundice and generalized seizures require intravenous medications.

Treatment of malaria in most cases is based on template regimens adopted for a particular region. For example, the pathogen P. falciparum acquired in the Middle East is sensitive to chloroquine, but if infection with the same type of malaria occurred in Africa, then this substance may not bring positive results in treatment.

Modern scientists have developed treatment regimens based on a combination of drugs with derivatives of the active antimalarial compound - artemisin. Examples of combination drugs:

• "Artesunate-Amodiaquine".
• "Artesunate-Mefloquine".
• "Dihydroartemisin-Piperaquine."

The development of new treatments for malaria is ongoing, which is associated with an increase in the number of drug-resistant strains of Plasmodium. One of the promising compounds in the creation of effective drugs against malaria is spiroindolone, which turned out to be effective against the pathogen P. falciparum in a number of experiments.

The drug "Primaquine" can be used to treat forms of malaria, the pathogens of which have been in an inactive state in the liver for a long time. This may prevent severe relapses of the disease. Pregnant women should not take Primaquine. This drug is also contraindicated for people who suffer from glucose-6-phosphate dehydrogenase deficiency. For this reason, the drug is not prescribed until a diagnostic screening test has ruled out the presence of this problem. In some countries, in addition to oral and injectable forms of drugs, suppositories are also used.

Disease during pregnancy

Malaria is a serious threat to a pregnant woman and her fetus. Infection significantly increases the risk of preterm birth and stillbirth. Statistics show that in sub-Saharan Africa, up to 30% of children die from malaria every year. Therefore, all pregnant women who live in dangerous areas or are planning a trip there should definitely consult a doctor and take prescribed medications, for example, Sulfadoxine-pyrimethamine. This is a necessary prevention of malaria to avoid infection.

Treatment of the disease in women expecting a child is carried out according to the standard scheme discussed above. However, drugs such as Primaquine, Tetracycline, Doxycycline and Halofantrine are not recommended due to potential danger to the fetus.

Disease in children

Prevention of malaria is mandatory for all children, including infants, living or spending time in areas where the disease is common. The following agents can act as preventive agents: Chloroquine and Mefloquine.

It is very important to use the correct dosage for your child, which depends on his age and weight. All parents, before traveling with their baby to countries at risk, should consult with a specialist in the field of childhood infectious diseases about the treatment and prevention of the disease in question. Because an overdose of an antimalarial drug can be fatal, all medications should be kept out of the reach of children, such as in tightly closed containers.

Prevention of infection

If a person intends to travel to an area where malaria is common, he must first find out what medications and in what dosages need to be taken to prevent infection. It is recommended to start taking these medications two weeks before the intended trip, during your stay in the country and for a month after returning from the trip. Currently, a vaccine against malaria has not been created, but intensive research is underway and a vaccine is under development.

If possible, avoid visiting countries with a high percentage of infected people, otherwise malaria prevention is mandatory - it can protect your health and save your life. If you are a traveler, try to stay informed about which places are currently experiencing outbreaks. The malaria carrier can land on human skin at any time of the day, but most bites occur at night. Insects are also most active at dawn and dusk. Avoid being outdoors during these hours. Prevention of infection is very important, given that there is no vaccine against malaria.

Wear appropriate clothing—pants, long-sleeved shirts, tall closed shoes instead of open sandals, and hats. Tuck your clothes into your pants. Use insecticidal repellents, for example, we can recommend Permethrin, which is used to treat clothing and equipment. Remember that good products contain up to fifty percent diethyltoluamide. Mosquito nets are especially necessary when the room is not ventilated, for example, there is no air conditioning. Treat them with aerosol repellents. It is also recommended to use mosquito coils.

Vaccine

Types of disease

The main types of pathogens of the disease were named above. The course of the disease may also vary. Let's name the main types of malaria:

• tropical;
• three-day;
• four-day;
• malaria-ovale.

Folk remedies

Medicines are the mainstay of malaria treatment. But many sources indicate the benefits of some natural remedies in the treatment of disease caused by Plasmodium. Here we publish only a few of them, and in no case should these recipes and recommendations be considered as the main means of treatment.

Lime and lemon are beneficial for four day fever. About three grams of chalk are dissolved in 60 ml of water and the juice of one lemon or lime is added. This composition must be drunk before the onset of fever.

Alum is also considered as a supportive agent in the treatment of malaria. They are fried in a hot frying pan and ground into powder. Take a teaspoon of the drug internally four hours before the expected fever and half a teaspoon two hours after it.

Malaria includes a group of acute infectious diseases transmitted primarily through blood. Variant names: intermittent fever, paludism, swamp fever. Pathological changes are caused by Anopheles mosquitoes and are accompanied by damage to blood cells, attacks of fever, and enlargement of the liver and spleen in patients.

Historical aspects

The historical focus of this disease is Africa. From this continent, malaria spread throughout the world. At the beginning of the 20th century, the number of cases was about 700 million per year. One out of 100 infected people died. The level of medicine of the 21st century has reduced morbidity to 350-500 million cases per year and reduced mortality to 1-3 million people per year.

Malaria was first described as a separate disease in 1696, at the same time the official medicine of that time proposed treating the symptoms of the pathology with cinchona bark, which had been used by folk medicine for a long time. The effect of this medicine could not be explained, because in a healthy person, quinine, when taken, caused complaints similar to fever. In this case, the principle of treating like with like, which was preached by Samuel Hahnemann, the founder of homeopathy, was applied in the 18th century.

The name of the disease that is familiar to us has been known since 1717, when the Italian physician Lancini established the cause of the development of the disease, coming from the “rotten” air of swamps (mal`aria). At the same time, suspicion arose that mosquitoes were responsible for transmitting the disease. The 19th century brought many discoveries in establishing the causes of malaria, describing the development cycle and classifying the disease. Microbiological studies made it possible to find and describe the infectious agent, which was named malarial plasmodium. In 1897 I.I. Mechnikov introduced the pathogen into the classification of microorganisms as Plasmodium falciparum(class of Sporozoans, type of protozoa).

In the 20th century, effective drugs were developed to treat malaria.

Since 1942 P.G. Müller proposed the use of the powerful insecticide DDT to treat areas of disease outbreaks. In the middle of the 20th century, thanks to the implementation of the global malaria elimination program, it was possible to limit the incidence to 150 million per year. In recent decades, an adapted infection has launched a new attack on humanity.

Pathogens of malaria

Under normal conditions, human malaria is transmitted by 4 main types of microorganisms. Cases of infection with this disease have been described in which the pathogens are not considered pathogenic for humans.

Features of the life cycle of malarial plasmodium

The causative agent of the disease goes through two phases of its development:

• sprorogony– development of the pathogen outside the human body ;
• schizogony

Sprorogony

When a mosquito (female Anopheles) bites a person who is a carrier of malaria germ cells, they enter the stomach of the insect, where the fusion of the female and male gametes occurs. The fertilized egg implants into the submucosa of the stomach. There the maturation and division of the developing plasmodium occurs. From the destroyed wall, more than 10 thousand developing forms (sporozoites) penetrate into the hemolymph of the insect.

The mosquito is infectious from now on. When another person is bitten, the sporozoites enter the body, which becomes the intermediate host of the developing malarial microorganism. The development cycle in the mosquito body lasts about 2-2.5 months.

Schizogony

In this phase we observe:

• Tissue stage. Sporozoites penetrate liver cells. There, they successively develop into trophozoites - schizonts - merozoites. The stage lasts from 6 to 20 days, depending on the type of plasmodium. Different types of malaria pathogens can simultaneously invade the human body. Schizogony can occur immediately after introduction or after some time, even months, which contributes to repeated returns of attacks of malaria.
• Erythrocyte stage. Merozoites penetrate the red blood cell and transform into other forms. Of these, from 4 to 48 merozoites are obtained, then morulation occurs (exit from the damaged erythrocyte) and re-infection of healthy erythrocytes. The cycle repeats. Its duration, depending on the type of plasmodium, ranges from 48 to 72 hours. Some merozoites turn into germ cells, which infect a mosquito that bites a person and transmits the infection to other people.

Note:In the case of malaria infection not from mosquitoes, but through a blood transfusion containing Plasmodium merozoites, only the erythrocyte stage occurs in the infected person.

The life cycle of Plasmodium is described in detail in the video review:

How does malaria become infected?

Children are especially susceptible to infection. The incidence in the foci is very high. Some people are resistant to malaria. It especially develops after repeated infections. Immunity does not last a lifetime, but only for an indefinite period.

Note:Malaria is characterized by a seasonal onset. Summer and hot months are most favorable for vectors of infection. In hot climates, the disease can occur all year round.

Malaria occurs in certain foci, monitoring of which makes it possible to predict the beginning of the seasonal surge, its maximum and attenuation.

In the classification, foci are divided into:

• seaside;
• flat;
• hilly-river;
• plateau;
• mid-mountain river.

The intensity of transmission and spread of malaria is assessed according to four types:

• hypoendmic;
• mesoendemic;
• hyperendemic;
• holoendemic.

The holoendemic type has the highest risk of infection and is characterized by the most dangerous forms of the disease. The hypoendemic type is characteristic of isolated (sporadic) cases of malaria.

Development of the disease and characteristic changes in the body

Note:the main pathological reactions occur as a result of the onset of erythrocyte schizogony.

The released biogenic amines contribute to the destruction of the vascular wall, cause electrolyte disturbances, and irritation of the nervous system. Many components of the life activity of plasmodia have toxic properties and contribute to the production of antibodies and protective immunoglobulin complexes against them.

The system reacts by activating the protective properties of the blood. As a result of phagocytosis (destruction and “eating” of diseased cells), the destruction of damaged red blood cells begins, causing anemia (anemia) in humans, as well as increased function of the spleen and liver. The total content of blood cells (erythrocytes) decreases.

Clinically, during these stages, a person experiences various types of fever. Initially, they are irregular, non-cyclical, and are repeated several times a day. Then, as a result of the action of immune forces, one or two generations of plasmodia remain, which cause attacks of fever after 48 or 72 hours. The disease acquires a characteristic cyclical course.

Note:the invasion process can last from 1 year to several decades, depending on the type of pathogen. Immunity after illness is unstable. Repeated infections often occur, but with them the fever is mild.

Against the background of malaria, pathological processes occur in the brain, symptoms of edema and damage to the walls of small vessels appear. The heart also suffers, in which severe degenerative processes occur. Necrobiosis forms in the kidneys. Malaria attacks the immune system, causing the development of other infections.

The disease occurs with periods of exacerbation of fever and normal state.

Main symptoms of malaria:

• attacks of fever (chills, fever, sweating);
• anemia (anemia);
• enlargement of the spleen and liver (hepatosplenomegaly);
• decrease in the number of red blood cells and platelets (pancytopenia).

As with most infectious diseases, there are three forms of severity of malaria - mild, moderate, severe.

The onset of the disease is sudden. It is preceded by an incubation period (the period of time from infection to the onset of the disease).

It amounts to:

• vivax malaria – 10-21 days (sometimes up to 10-14 months);
• four-day malaria – from 3 to 6 weeks;
• tropical malaria – 8-16 days;
• ovale malaria – 7-20 days.

Sometimes there is a prodromal period (the time of onset of malaria, accompanied by initial, mild symptoms). The patient experiences weakness, chilling, thirst, dry mouth, pain in the head.

Then a fever of the wrong type suddenly appears.

Note:The first week of the febrile period is characterized by attacks occurring several times a day. In the second week, paroxysms acquire a clear cyclic course, repeating every other day or two (with four-day fever)

How does a fever attack proceed?

The duration of the paroxysm is from 1-2 hours to 12-14 hours. A longer period is determined for tropical malaria. It can last a day or even more than 36 hours.

Attack phases:

• chills – lasts 1-3 hours;
• fever - up to 6-8 hours;
• profuse sweating.

Complaints and symptoms during malarial paroxysm:

After sweating comes sleep. During the interictal period, patients are able to work, but as the disease progresses, their condition worsens, there is loss of body weight, jaundice, and the skin becomes sallow in color.

Tropical malaria is the most severe.

In her case, the following are added to the described symptoms of malaria:

• severe pain in the joints and throughout the body;
• signs characteristic of meningitis;
• delusional state of consciousness;
• attacks of suffocation;
• frequent vomiting with blood;
• pronounced enlargement of the liver.

In the first week of illness, attacks can occur, layering on each other. A few months after the onset of the disease, paroxysms begin to recur, but in a milder form.

Of all the described forms of malaria, vivax is the most mild. The largest number of relapses is observed with Chesson malaria (Pacific form).

note:Cases of a fulminant course have been described, which led to death from cerebral edema within a few hours.

Complications of malaria

In weakened or untreated patients, as well as in case of treatment errors, the following complications may develop:

• malarial coma;
• edema syndrome;
• extensive hemorrhages (hemorrhages);
• different types of psychoses;
• renal and liver failure;
• infectious complications;
• splenic rupture.

A separate complication of malaria should be noted hemoglobinuric fever. It develops against the background of massive proliferation of plasmodia, during treatment with medications, due to the destruction of red blood cells (hemolysis). In severe cases of this complication, a progressive decrease in urine production is added to the general symptoms and complaints of an attack of malaria. Fulminant renal failure develops, often with early death.

Diagnosis of malaria

Malaria is determined based on:

• collection of anamnestic data - the survey reveals pre-existing malaria, cases of blood transfusion to the patient;
• epidemiological history – the patient’s residence in areas with existing outbreaks of the disease;
• clinical signs - the presence of characteristic complaints and symptomatic picture of malaria;
• laboratory diagnostic methods.

The first three points are discussed in detail in the article. Let's touch on laboratory testing methods.

These include:

Confirmation of diagnosis using specific methods

To confirm the diagnosis, blood is tested using "thick drop" And "smear".

The analysis allows you to determine:

• a type of malarial plasmodium;
• stage of development;
• level of invasiveness (number of microbes).

Invasiveness is assessed in 4 degrees (in the field of view of the microscope):

1. IVdegree– up to 20 cells per 100 fields .
2. IIIdegree– 20-100 plasmodia per 100 fields.
3. IIdegree– no more than 10 in one field;
4. Idegree– more than 10 in one field.

The method is quite simple, cheap and can be used frequently to monitor the patient’s condition and the effectiveness of treatment.

Analysis "thin drop" is prescribed as an addition to the previous one in case of necessary differential diagnosis.

An express diagnostic method is immunological analysis determination of specific proteins of falciparum plasmodium. It is carried out in foci of tropical malaria.

Serological tests for malaria

Material: venous blood.

The goal is to detect antibodies to malaria .

Result assessment – ​​titer less than 1:20 – negative analysis; more than 1:20 – positive.

Polymerase chain reaction ()

The test is specific in nature, allowing it to detect malaria in 95% of cases. Venous blood is used. The negative point is the high cost. Required in doubtful cases.

Mosquitoes are also tested for the presence of Plasmodium falciparum cells.

Treatment of malaria

Modern treatments for malaria are very effective. They are indicated at different stages of the disease. Today, a large number of medications have been developed to cope with the disease even in advanced situations. Let us dwell on the principles of treatment and a description of the main drug groups.

Note: Therapy must be started immediately after diagnosis in an infectious diseases hospital.

Goals of malaria treatment:

• destruction of the pathogenic plasmodium in the patient’s body;
• treatment of associated complications;
• prevention or mitigation of relapse clinics;
• stimulation of specific and nonspecific immunity.

Groups of medications for the treatment of malaria

The main groups of medicines include:

1. Quinolylmethanols - derivatives of Quinine, Delagil, Plaquenil, Lariam, Primaquine.
2. Biguanides – Bigumal.
3. Diaminopyrimidines – Daraprim.
4. Terpene lactones – Artesunate.
5. Hydroxynaphthoquinones – Mepron.
6. Sulfonamides.
7. Tetracycline antibiotics.
8. Lincosamides – Clindamycin.

People with malaria need care. Diet – table 15 according to Pevzner during periods of remission and table 13 during a febrile period. Recommended - lean meat and fish, soft-boiled eggs, porridge, kefir, fermented baked milk, boiled vegetables, fresh pureed fruit, juices, fruit drinks, crackers, honey.

Preventive actions

Preventive work is carried out at the site of infection through the use of mosquito nets and insecticides, which are used to treat areas where mosquitoes accumulate. At home, it is necessary to use repellents, aerosols and ointments that repel mosquitoes and cause their death.

If a possible infection is suspected, medications are taken in doses prescribed by an infectious disease specialist.

Vaccine prevention is currently being developed.

People located in the epicenter of the epidemic are subject to isolation and laboratory examination if an elevated temperature occurs. The earlier treatment is started, the better the result. People arriving from countries with malaria outbreaks must be examined. Those who have recovered from the disease must be observed by an infectious disease specialist for 3 years.