Malaria Flashcards
What is Malaria?
a potentially life‑threatening tropical infectious disease caused by Plasmodium parasites, which are transmitted through the bite of an infected female Anopheles mosquito
Epidemiology of Malaria?
- Most cases of malaria occur in tropical Africa (West and Central Africa).
- Transmission also occurs in other tropical and subtropical regions such as South and Southeast Asia, and Central and South America
Incubation period of malaria?
7-30 days
- The incubation period of malaria is a minimum of seven days; if fever occurs before the seventh day following exposure in an endemic region, it is most likely not due to malaria.
Symptoms of malaria?
nonspecific symptoms like fever, nausea, and vomiting
Gold standard for diagnosing malaria?
- identification of parasites in RBCs on a blood smear
- although rapid diagnostic tests to identify Plasmodium antigens are used with increasing frequency
Classification of malaria?
- severe
- uncomplicated
Signs of severe malaria?
characterized by severe organ dysfunction
Treatment of severe malaria?
affected individuals should be admitted to the ICU and receive IV antimalarials immediately
Treatment for uncomplicated malaria?
treated with oral antimalarials
Pathogen that causes malaria?
plasmodia
- eukaryotic parasite belonging to the sporoza group
Name the different types of plasmodia?
- plasmodium falciparum - most virulent
- plasmodium vivax
- plasmodium ovale
- plasmodium knowlesi
- plasmodium malariae
Malaria vector?
the female anopheles mosquito
What conditions offer partial resistance against malaria?
- carriers of sickle cell mutation
- Other hemoglobinopathies (e.g., thalassemia, HbC)
- Infection with malaria subsequently leads to the development of specific Plasmodium antibodies that result in partial immunity for a limited amount of time (less than a year)
Pathophysiology - asexual development in humans?
- Transmission of Plasmodium sporozoites via Anopheles mosquito bite → sporozoites travel through the bloodstream to the liver of the host
- Liver: sporozoites enter hepatocytes → sporozoites multiply asexually → schizonts are formed containing thousands of merozoites → release of merozoites into the bloodstream
- Circulatory system: Merozoites enter erythrocytes → maturation to trophozoites → red cell schizonts are formed containing thousands of merozoites → release of merozoites into the bloodstream (which causes fever and other manifestations of malaria) → penetration of erythrocytes recurs
- Merozoites enter erythrocytes → differentiation into gametocytes (male or female)
- Gametocytes mature into oocysts in the mosquito → mature into sporozoites
Pathophysiology - sexual development in female Anopheles mosquito?
A mosquito bites an infected human and ingests gametocytes → gametocytes mature within the mosquito intestines → sporozoites are formed and these migrate to the salivary glands → transmission of sporozoites to humans via mosquito bite