Malaria -Cause,Types, Symptoms, Prevention and Treatment
What is Malaria?
Malaria is an infectious disease caused by the protozoan parasite belonging to the genus Plasmodium, transmitted by the female anopheles and characterized by intermittent fever, chills, rigors, and organomegaly.
Causes of malaria
It is caused by the protozoan parasite belonging to the genus Plasmodium. Five species of plasmodium are responsible for causing this disease in humans. They are P.falciparum, P.malariae, P.ovale, P.vivax, and P.knowlesi. Plasmodium falciparum and Plasmodium vivax are responsible for the majority of the cases.
It is transmitted by the female anopheles mosquito, which lays its eggs in the water, which hatch into larva and transform into adult mosquitos.
Plasmodium is the protozoan parasite causing malaria. It needs two hosts to complete its lifecycle. Its life cycle is divided into lifecycle in mosquito and human lifecycle.
Lifecycle in mosquito
The sexual parasitic forms enter the mosquito when the mosquito is feeding on human beings, and it enters the gut of the mosquito and forms an oocyte (similar to the embryo) in the gut wall. Then the oocyte bursts releasing the sporozoites in the mosquito, which enters another human being when it bites and releases its salivary secretions into the humans.
Lifecycle in humans
Lifecycle in humans can be divided into the hepatic life cycle and erythrocytic life cycle.
Hepatic life cycle
It occurs when the sporozoites enter the human liver through circulations and start multiplying and forming several merozoites, which are the asexual forms of the parasite.
Erythrocytic life cycle
This occurs when meroziotes released from the liver enters the red blood cells and starts forming sexual forms, which will infect another mosquito.
Types of malaria
The types of malaria are classified based on the plasmodium species and also the severity of the symptoms. Symptoms differ between the types of this disease.
Classification based on the infective species:
- Plasmodium falciparum: Responsible for severe cases of this disease in tropical and subtropical regions.
- Plasmodium vivax: Responsible for ocurence of this disease in Asia and Latin America.
- Plasmodium ovale: Responsible for occurrence of this diseases in Africa and the Pacific islands.
- Plasmodium malariae: It is responsible worldwide for this disease.
- Plasmodium knowlesi: this species is found in South East Asia and can cause rapid deterioration of symptoms.
Classification based on the severity of symptoms:
- Uncomplicated type: Characterized by fever, chills, rigors, fatigue, body pains, joint pains, nausea, vomiting, headaches, and jaundice.
- Complicated type: It is characterized by decreased consciousness, weakness, inability to feed, seizures, low blood pressure, difficulty in breathing, low blood glucose levels, hemoglobin levels less than 5g/dL, organ failure, and shock.
Symptoms of malaria
The symptoms of this disease overlap with some infectious diseases such as typhoid, viral fever, Urinary tract infections, flu, and gastroenteritis.
- Fever with chills and rigors
- Body pains
- Joint pains
- Enlargement of liver and spleen
- Decreased consciousness
- Inability to feed
- Low blood pressure
- Difficulty in breathing
- Low blood glucose levels
- Hemoglobin levels less than 5g/dL
- Organ failure
- Circulatory Shock.
Symptoms of malaria Vs typhoid
It is important to differentiate between malaria and typhoid since there is an overlapping of the spectrum of symptoms between the two diseases.
|Caused by protozoan parasite belonging to the genus plasmodium||Caused by gram-negative bacteria called Salmonella typhi|
|Transmission occurs by bite of female anopheles mosquito||Transmission occurs by feco-oral route by contaminated food and water|
|Intermittent fever with chills, rigors, nausea, vomiting, and headache.||High-grade continuous fever, abdominal pain, decreased heart rate, diarrhea, constipation, cough, fatigue, rose spots on the abdomen, and gastrointestinal bleeding|
|Complications: cerebral malaria, seizures, confusion, unconsciousness, coma, and even death||Complications: gastrointestinal bleeding, peritonitis due to perforation of the gut, endocarditis, and encephalitis.|
|Diagnostic tests: complete blood count, hemoglobin, peripheral smear for the malarial parasite, and rapid diagnostic tests.||Diagnostic tests: Widal test, typhoid test, bone marrow test, and stool examination.|
Prevention of malaria
It can be prevented by preventing the transmission by mosquitos and by reducing the mosquito population (vector control), and by taking antimalarial prophylaxis.
- Using mosquito nets
- Using insecticide-treated nets
- Using insect repellants ointments or creams
- Indoor spraying of residual insecticides
- Covering open sources of stagnant water to prevent the breeding of mosquitos
- Adding fish which feeds on the mosquito larva to the water bodies can also help in decreasing the mosquito population.
It is important for people traveling to malaria-endemic regions to take prophylaxis before, during, and after the travel.
The treatment of malaria includes medications to decrease parasitic load and prevent multiplication of parasites and supportive management.
The drugs used for the treatment of this disease are chloroquine, doxycycline, quinine, mefloquine, atovaquone, proguanil, and primaquine phosphate.
The supportive management of this disease includes replenishing body fluid levels, administration of electrolytes, glucose, and blood transfusions to treat anemia.