Alternative Names: Quartan malaria; Falciparum malaria; Biduoterian fever; Blackwater fever; Tertian malaria; Plasmodium
Malaria is a blood disease transmitted to humans through the bites of the female anopheles mosquito which infects the body with the Plasmodium parasite. Once an infected mosquito bites a human and transmits the parasites, those parasites multiply in the host’s liver before infecting and destroying red blood cells. The host may show no symptoms for the next 5 -16 days while the parasite multiplies. Incubation period is said to vary between 7 to 30 days. Infection with the parasite is almost always universal in endemic populations and the presence of the pathogen is not a sufficient marker of the disease. The female anopheles is the only mosquito that can cause malaria.
Causes: Malaria is caused by a type of microscopic parasite that’s transmitted most commonly by mosquito bites.
Mosquito transmission cycle: Uninfected mosquito. A mosquito becomes infected by feeding on a person who has malaria.
- Transmission of parasite. If you’re the next person this mosquito bites, it can transmit malaria parasites to you.
- In the liver. The parasites then travel to your liver — where some types can lie dormant for as long as a year.
- Into the bloodstream. When the parasites mature, they leave the liver and infect your red blood cells. This is when people typically develop malaria symptoms.
- On to the next person. If an uninfected mosquito bites you at this point in the cycle, it will become infected with your malaria parasites and can spread them to the next person it bites.
Other modes of transmission: Because the parasites that cause malaria affect red blood cells, people can also catch malaria from exposures to infected blood, including: From mother to unborn child, through blood transfusions, and by sharing needles used to inject drugs
Symptoms: Infection may result in a wide variety of symptoms including fever, chills, headaches, general malaise, sweats, body aches and nausea. In a non-immune individual, symptoms usually appear 10-15 days after the infective bite.
Children with severe malaria often develop one or more of the following symptoms: severe anaemia, respiratory distress in relation to metabolic acidosis, or cerebral malaria.
In countries where cases of malaria are infrequent, the symptoms may be attributed to influenza, cold or other common infections. Conversely, in countries where malaria is frequent, residents often recognize the symptom as malaria and treat themselves without diagnosis. The practice of treatment without proper testing and diagnosis is widely discouraged.
Malaria can be fatal, especially among children under 5 years and expectant mothers, but it is a curable disease if diagnosed and treated promptly and correctly.
Malaria Globally: The World Health Organization (WHO) estimates that malaria caused 212 million clinical episodes and 429,000 deaths in 2015. African countries carry a disproportionately high share of the global malaria burden. In 2015 the region was home to 90% of malaria cases and 92% of malaria deaths. Young children and pregnant mothers bear the brunt of the malaria mortality burden.
Between 2010 and 2015 however malaria incidences among at risk populations (the rate of new cases) fell by 21% globally. In that same period, malaria mortality rates among populations at risk fell by 29% globally among all age groups and by 35% among children under 5.
Risk factors: The biggest risk factor for developing malaria is to live in or to visit tropical areas where the disease is common. Many different subtypes of malaria parasites exist. The variety that causes the most lethal complications is most commonly found in: African countries south of the Sahara Desert, The Asian subcontinent and Solomon Islands, Papua New Guinea and Haiti.
People at increased risk of serious disease include: Young children and infants, Travelers coming from areas with no malaria and Pregnant women and their unborn children. Poverty, lack of knowledge, and little or no access to health care also contribute to malaria deaths worldwide.
Immunity: Residents of a malaria region may be exposed to the disease so frequently that they acquire a partial immunity, which can lessen the severity of malaria symptoms. However, this partial immunity can disappear if you move to a country where you’re no longer frequently exposed to the parasite.
Complications: Malaria can be fatal, particularly the variety that’s common in tropical parts of Africa. The Centers for Disease Control and Prevention estimate that 90 percent of all malaria deaths occur in Africa — most commonly in children under the age of 5.
In most cases, malaria deaths are related to one or more serious complications, including:
- Cerebral malaria. If parasite-filled blood cells block small blood vessels to your brain (cerebral malaria), swelling of your brain or brain damage may occur. Cerebral malaria may cause coma.
- Breathing problems. Accumulated fluid in your lungs (pulmonary edema) can make it difficult to breathe.
- Organ failure. Malaria can cause your kidneys or liver to fail, or your spleen to rupture. Any of these conditions can be life-threatening.
- Anemia. Malaria damages red blood cells, which can result in anemia.
- Low blood sugar. Severe forms of malaria itself can cause low blood sugar, as can quinine — one of the most common medications used to combat malaria. Very low blood sugar can result in coma or death.