Malaria - What Is The Causative Agent? First Symptoms, Treatment And Prevention

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Video: Malaria - What Is The Causative Agent? First Symptoms, Treatment And Prevention

Video: Malaria - What Is The Causative Agent? First Symptoms, Treatment And Prevention
Video: Malaria - causes, symptoms, diagnosis, treatment, pathology 2023, March
Malaria - What Is The Causative Agent? First Symptoms, Treatment And Prevention
Malaria - What Is The Causative Agent? First Symptoms, Treatment And Prevention

Malaria: first symptoms and treatment


Malaria is an infectious disease caused by parasites, namely, Plasmodium malaria. The infection spreads through the blood, and its carriers are the female anopheles mosquito. A person becomes infected when this insect bites him.

A patient with malaria rises in body temperature, he is very chilly. Sweating is very intense.

In developed countries with temperate climates, this disease is rare. Infection cases are reported in the tropics and subtropics. Moreover, often the disease becomes the cause of human death. Not only residents of these climatic zones, but also tourists can become infected. The leadership of states from the risk group directs efforts to fight the disease, but they cannot completely get rid of it. Malaria kills about 660,000 people every year. That is why it is so important to know the symptoms of malaria. This will allow you to start treatment on time and save the person's life.


  • What is malaria?
  • Types of malaria
  • Disease development
  • Potentially dangerous regions
  • Malaria symptoms
  • Complications
  • Diagnostics
  • Malaria treatment
  • After recovery
  • Malaria during pregnancy
  • Malaria in children
  • Prevention of malaria
  • Malaria vaccine development

What is malaria?

What is malaria
What is malaria

Malaria is an infectious disease in which red blood cells are affected. They are damaged by intracellular parasites of the genus Plasmodium.

Translated from the Italian language, malaria (mala aria) means "bad air". This disease was formerly called swamp fever.

The spread of the infection is the female anopheles mosquito. Parasites are transmitted to humans during an insect bite, that is, by blood.

There are three possible routes of infection with tropical malaria:

  • Transmission type. Infection occurs during the bite of an Anopheles mosquito.
  • Parenteral. The infection is transmitted by blood, during blood transfusion or during organ donation. There is also a risk of contracting malaria during surgery if the instruments used by the surgeon are infected.
  • Transplacental. The disease is transmitted to the child from the mother.

Malaria is a seasonal infection. Its outbreaks are recorded during the hot and humid season. People living in high-risk areas are regularly screened for malaria. When cases of illness are found, treatment is prescribed.

Types of malaria

Types of malaria
Types of malaria

Although scientists know more than 4,000 species of protozoa of the order Coccidiida and the genus Plasmodium, it has been established that only five of them can become a distributor of malaria:

  • Plasmodium falciparum. It is the most formidable parasite and causes the severe form of tropical malaria. Coping with the disease will be difficult, as the infection does not respond well to therapy.
  • Plasmodium vivax. This parasite causes malaria as often as Plasmodium falciparum, but it is not as dangerous to the human body. Residents of India, Central and South America mainly suffer from the disease. Once in the human body, the parasite causes symptoms of the disease, which, thanks to treatment, can be eliminated. However, this does not mean that they managed to get rid of the infection. The liver becomes the "home" of the parasite. After recovery, the disease may reappear after several years.

  • Plasmodium ovale. This parasite is common in African countries. He, too, can live in the liver, causing re-disease after several years. Experts call this infection "ovale malaria".
  • Plasmodium malaria. This parasite is not so common, but it provokes the development of a disease, which can be difficult to identify. Plasmodium circulates in the patient's blood a little, so this malaria (four-day malaria) can last for several years.
  • Plasmodium knowlesi and Plasmodium cynomolgi. These parasites cause infection in monkeys. However, scientists have data on human infection. A person gets sick immediately after infection, the infection does not recur. This form of malaria affects mainly Malaysians.

A person can suffer from different types of malaria. Sometimes infection occurs at the same time. The disease is difficult to diagnose and treat, since it is difficult to cope with several types of parasites at once.

Depending on the period of malaria, there are:

  • Primary infection.
  • Malaria in early relapse (recurrence of symptoms occurs less than six months after the first case).
  • Distant relapses of malaria, of which there may be several.
  • The period of latent malaria.

Depending on the severity of the course of the disease, there are:

  • Mild malaria.
  • Moderate malaria.
  • Severe malaria.
  • Malignant malaria.

Sometimes "malaria on the lips" is the manifestation of a herpes infection (when infected with herpes type 1). In fact, this name is incorrect, since it has nothing to do with malaria.

Disease development

Disease development
Disease development

After infection, the parasites enter the general bloodstream. This happens during an insect bite, when it feeds on the blood of its victim. Then comes the incubation period. At this time, the person does not know that he is infected, since there are no symptoms of the disease. The latent period can last for several days. It all depends on the specific type of pathogen.

Plasmodium falciparum is detected faster than others, it makes itself felt on 6-8 days. It does not cause symptoms of Plasmodium malariae disease longer than others. The incubation period extends to 14-16 days.

When the prodromal period begins, the patient feels the first signs of infection. At this time, his general health worsens, chills, headaches may occur. The average duration of the prodromal phase is 5 days.

Then malaria makes itself felt in full force. The acute stage of the disease sets in. At this time, the body temperature rises greatly, there are a series of febrile attacks. Each of them can last from 3 to 10 hours. After that, the person feels better. The symptoms of the disease are declining.

Potentially dangerous regions

Malaria is a common infection. The disease occurs in the West Indies, Mexico, Central America. Residents of the northern regions of South America suffer from the infection, especially those who live in the Amazon Valley. For Africans, disease is also a problem. Cases of malaria have been reported among residents of the Red and Mediterranean Seas, Ukraine and the Balkans. Every year, data comes in about the infected residents of Southeast Asia, India and northern Australia.

Potentially dangerous regions
Potentially dangerous regions

The spread of malaria in the world, given its drug resistance:

  • Common strains are shown in brown on the map.
  • Areas in which the malaria strains are resistant to Chloroquine are shown in red.
  • Areas inhabited by mosquitoes that spread non-fatal infections are indicated in light brown.
  • Areas where malaria is absent at all are marked in gray.

Plasmodium falciparum is the most common parasite that causes malaria in Africa. It is from him that most of all the people in the whole world die.

Plasmodium vivax is distributed outside African countries. This parasite causes malaria in the southern parts of the Sahara.

Until 1950, massive outbreaks of malaria were recorded in the USSR. Moreover, not only the inhabitants of the Caucasus suffered from the infection, but also the population of Central Asia, Transcaucasia, and central Europe. The peak of malaria was observed in 1934-1935. At this time, 9 million cases of the disease were recorded. However, by 1960, malaria was completely eliminated.

Malaria affects 350-500 million people worldwide every year. About 1.3-3 million people die from the disease. Approximately 90% of cases are from Sub-Saharan Africa. Moreover, mainly children under 5 years old are infected there.

Malaria symptoms

After a person has been bitten by a mosquito carrying malaria, it takes about 2 days for them to develop symptoms of the disease. If the immune system is active and strong, then this period can last up to 7 days.

From the first symptoms, it is impossible to understand that a person develops malaria. They can characterize various diseases.

Early manifestations of infection include:

  • Fatigue and weakness.
  • Lack of desire to eat.
  • Dizziness.
  • Headache. This symptom only occurs with Plasmodium falciparum infection.
  • Disruption of the digestive tract: nausea, diarrhea, vomiting, abdominal pain.
  • Sometimes blood impurities appear in the feces. This symptom also characterizes infection with Plasmodium falciparum.
  • Muscle pain.
Malaria symptoms
Malaria symptoms

Symptoms characteristic of malaria appear later:

  • Cyclic fever. Periods last 3 or 4 days, or continuously.
  • Limb tremor. It also comes up from time to time.
  • Joint pain. This trait characterizes Plasmodium falciparum.
  • Anemia that develops against the background of hemolysis.
  • A severe course of Plasmodium falciparum leads to paralysis.
  • In the malignant form of the disease, a person develops cerebral edema. It builds up quickly and is fatal. This course is typical for malaria caused by Plasmodium vivax.

Other symptoms of malaria include enlargement of the liver and spleen in size, a sharp drop in blood sugar levels, and impaired kidney function. If the kidneys are working, then the hemoglobin from the red blood cells can enter the urine.

Severe malaria is characterized by rapid development. This often leads to the death of a person. Sometimes death occurs within a few hours after the first symptoms appear. Therefore, the diagnosis of malaria must be highly accurate.



Complications of malaria include:

  • Malaria coma. Most often women in position, young people and children suffer from it.
  • Acute renal failure. Diuresis is reduced to 400 ml per day.
  • Hemoglobinuric fever. It occurs due to the massive destruction of red blood cells, which leads to the release of toxins into the blood. With this complication, the patient's urine output rapidly decreases, which leads to progressive renal failure. Often such cases end in the death of the patient.
  • Malaria algid. This complication proceeds as an inflammation of the brain, but the person's consciousness is not impaired.
  • Pulmonary edema. His symptoms are growing rapidly, often this complication ends in the death of the patient.
  • Rupture of the spleen, which occurs due to torsion of the leg of the organ. If the patient is not provided with emergency medical care, he may die from blood loss.
  • Severe anemia due to hemolysis.
  • DIC syndrome. First, the blood coagulates directly in the vessels, and then the patient develops bleeding.

A person's consciousness can be disturbed. This process goes through 3 phases:

  • Doubtfulness. A person loses physical activity, becomes drowsy, refuses to contact other people.
  • Sopor. Consciousness is inhibited. A person gives a reaction only to pronounced stimuli. Reflexes are minimal, and seizures are frequent. Symptoms of impaired consciousness can proceed as meningitis.
  • Coma. The patient is unconscious, reflexes are absent.



To diagnose malaria, the following blood tests are done:

  • Examination of a thick drop of blood.
  • Thin blood smear. If the doctor detects changes characteristic of malaria in a thick drop, he prescribes this study. It allows you to clarify the type of pathogen and the stage of its development.

The methods of immunological research include:

  • Determination of proteins to Plasmodium falciparum. This method can diagnose tropical malaria. It is often used in countries where the tropical form of the disease is widespread. A person can even perform such a test independently. It requires blood from a finger.
  • ELISA. This method examines venous blood. It detects antibodies that are produced in response to parasitic infection. Most often, ELISA is used in countries where malaria is not widespread.
  • PCR or polymer chain reaction for malaria. For the study, blood is taken from a vein, or a thick drop of blood is taken from a finger. This method allows you to detect the causative agent of the disease. They resort to PCR to detect difficult-to-diagnose forms of malaria.

When the disease has just begun to develop, it can be confused with pneumonia, food poisoning, influenza, meningitis, etc. As the pathology progresses, the symptoms become more specific. However, differential diagnosis is carried out with diseases such as typhoid fever, yellow fever, tuberculosis, viral hepatitis, leptospirosis, sepsis, leukemia.

Malaria treatment

Malaria treatment
Malaria treatment

The main goals to be achieved in the course of malaria treatment are:

  • Elimination of the parasite in the human body.
  • Getting rid of the complications of pathology.
  • Prevention of relapse of the disease and relief of pathological symptoms.
  • Increased immunity.

Immediately after the diagnosis is made, the patient is hospitalized. Treatment is carried out only in a hospital.

Types of treatment:

  • Conducting specific therapy. The patient is prescribed drugs that can destroy the causative agent of the disease.
  • Conducting symptomatic therapy. It is necessary to stop the symptoms of the disease when they have a vivid manifestation.
  • Compliance with the patient care regimen.

Antimalarial drugs

You can cope with malaria with drugs that contain quinine, mefloquine, chloroquine, fansidar, metakelfin, artemisin, proguanil. Some drugs are used only for prophylactic purposes, others can completely cope with malaria. There is no universal drug for the treatment of infection, since different forms of the disease are recorded in different regions. In addition, some parasites have learned to adapt to ongoing drug therapy and do not respond to it. Therefore, the drug is selected in each case individually.

Previously, malaria was actively treated with drugs containing artemisinin. In recent years, there has been a tendency for Plasmodium falciparum to be resistant to this drug. The parasites have learned to resist it. Thus, resistant cases have been identified in Myanmar, Vietnam, Thailand, Cambodia, Laos.

To cope with the infection, it is increasingly necessary to resort to combination therapy with the inclusion of artemisinin in the treatment regimen.

WHO recommends the use of drugs to get rid of malaria such as:

  • Artemether / lumefantrine. Trade name of the drug Coartem. In a number of countries, it can be found under the Riamet brand. The drug is used to treat infection.
  • Artesunate / amodiaquine (Artesunate / amodiaquine) - used for prophylactic purposes.
  • Malarone - for both treatment and prevention. Its other name is Malanil. The main active ingredient in this drug is Atovaquone / proguanil.
  • Quinine. Used to treat disease
  • Chloroquine. Trade name of the drug Delagil. It is used for both therapeutic and prophylactic purposes.
  • Cotrifazid - Used to prevent and treat malaria.
  • Doxycycline Prescribed for preventive and therapeutic purposes.
  • Lariam containing mefloquine (Mefloquine) is used for prophylactic purposes, as well as for the treatment of malaria.
  • Savarin containing proguanil is used only for treatment.
  • Primaquine is used exclusively for prevention.
  • Fansidar containing the substances sulfadoxine / pyrimethamine (Sulfadoxine / pyrimethamine) is used both for the treatment of the disease and for prophylactic purposes.

In Russia, not all of the listed medicines are allowed for use.

If a case of malaria was registered on the territory of the Russian Federation, then the patient can be prescribed drugs such as:

  • Quinine.
  • Delagil containing Chloroquine.
  • Plaquenil based on hydroxychloroquine.
  • Lariam with mefloquine.
  • Fansidar. It is a combination drug with pyrimethamine and sulfadoxine.
  • Doxycycline, which is a broad spectrum antibiotic.

Plasmodium falciparum, a causative agent of malaria, is virtually unresponsive to chloroquine drugs.

For the prevention of recurrence of the disease, all adult patients (with the exception of pregnant women and children with glucose-6-phosphate dehydrogenase deficiency), in addition to therapy with chloroquine or artemisinin, are additionally prescribed primaquine. The course should last 2 weeks.

If malaria has been provoked by parasites such as Plasmodium falciparum, Plasmodium vivax or Plasmodium knowlesi and has a severe course, then parenteral administration of Artemetrin or Artesunate is necessary. Then the patients are prescribed combination drugs containing Artemisinin. WHO recommends the provision of emergency care to all patients with severe malaria.

Malaria therapy in Russia is rather difficult. Not every medical institution has a specialist who can make the correct diagnosis. Even after malaria has been confirmed, the country may simply not be able to find drugs to treat it.

After recovery

After recovery
After recovery

If the infection was caused by parasites such as Plasmodium vivax or Plasmodium ovale, then it is impossible to exclude the risk of a relapse of the pathology. These infectious agents can exist asymptomatically in the human liver for a long time.

If, after treating malaria, after a while, the condition begins to worsen again, you need to see a doctor.

A person who has suffered from malaria cannot donate blood for 3 years. After this period, donation is possible, but medical personnel must be warned that such an infection was transferred 3 years ago.

Malaria during pregnancy

Pregnant women are seriously ill with malaria. This infection can cause miscarriage or early labor. If a woman in a position went on a trip to countries with a high risk of infection, or lives there, then efforts should be made to prevent the disease.

Parasites such as Plasmodium falciparum and Plasmodium vivax lead to intrauterine fetal death.

If a pregnant woman contracted malaria, she needs to seek medical help as soon as possible. Most of the drugs designed to fight this infection do not harm the child's health or affect his development.

Malaria in children

Malaria in children
Malaria in children

Malaria is dangerous for children, as it has an aggressive course. If the child does not receive therapy, then he remains at a high risk of developing complications.

In children under 5 years of age, the disease does not lead to an increase in body temperature. Therefore, the body cannot cope with Plasmodium on its own. This explains the high mortality rate among children.

Treatment of malaria in childhood is carried out in the same way as in adults, but the dose of drugs is reduced.

Prevention of malaria

If a person goes on a trip to a country where malaria is "raging", or lives in such states, you need to take care of preventive measures. Preparation should be taken seriously. It is not recommended for people with HIV to travel to malaria-pandemic countries, as well as for children under 4 years of age.

Before starting a trip, you need to check with the embassy of the country how things are with malaria in a specific period of time. This will allow you to take the necessary action.

Protection against mosquito bites

The most reliable way to prevent disease is to prevent mosquito bites.

It is impossible to protect yourself from insects by 100%, but recommendations such as:

  • Use of mosquito nets. They are installed in windows and door openings.
  • Use of network curtains. They need to be tucked into the mattress. You can sleep in such a bed without fear.
  • The use of repellents. These substances scare away insects, but they will not be able to destroy them. Repellents are applied to clothing or skin. They are available in the form of sprays, aerosols, gels, creams, etc. These products should be used according to the instructions provided.
  • Application of insecticides. These drugs can kill insects. They come in aerosol form. To kill mosquitoes, you need to spray them indoors, apply to thresholds and mosquito nets. Half an hour after treatment, the room is ventilated.

Malaria drug prevention

In order to prevent infection, you can take drugs that are used to treat the disease. However, when infected, an integrated approach will be required. For prophylactic purposes, you can take Lariam, Quinine, Primahine, Malaron, etc.

It must be remembered that these drugs are harmful to human health and have multiple side effects. They are taken 2 times a week, 14 days before the trip and 14 days after it.

Before starting prophylaxis with drugs, it is necessary to clarify which drugs the parasites have developed resistance to. It differs from country to country.

Every person who arrives from a country that is dangerous in terms of infection must be examined. If an infection occurs, then within 3 years the patient will be registered with an infectious disease specialist.

Malaria vaccine development

Malaria vaccine development
Malaria vaccine development

It is impossible to find a vaccine for malaria on sale. Scientists are making efforts to create it, but research has not yet been completed.

In 2017, it was announced that the drug had been developed. In the journal Nature, information appeared that the created vaccine is 100% effective. 67 volunteers took part in the tests. They received the drug Sanaria PsfPZ-cv. Those who were given the high dose developed immunity against malaria. It continued to act for 10 weeks after its introduction. The subjects did not develop side effects. The experiments are being carried out in the African country of Gabon. Now the second stage of testing is underway. Doctors study how the vaccine will behave for several years after it is given.

Sanaria PsfPZ-cv is not the only effective vaccine against the disease. In 2018, WHO announced that it had begun an experiment with the licensed Mosquirix vaccine. Her research is being carried out in 3 African countries. The effectiveness of the drug is 50%, but its improvements continue.


Article author: Mochalov Pavel Alexandrovich | d. m. n. therapist

Education: Moscow Medical Institute. IM Sechenov, specialty - "General Medicine" in 1991, in 1993 "Occupational Diseases", in 1996 "Therapy".

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