Malaria is caused by Plasmodium parasites. The parasites are spread to people through the bites of infected female Anopheles mosquitoes, called “malaria vectors.” There are 5 parasite species that cause malaria in humans, and 2 of these species – P. falciparum and P. vivax – pose the greatest threat.
- P. falciparum is the most prevalent malaria parasite on the African continent. It is responsible for most malaria-related deaths globally.
- P. vivax is the dominant malaria parasite in most countries outside of sub-Saharan Africa.
- Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. It is preventable and curable.
- In 2016, there were an estimated 216 million cases of malaria in 91 countries, an increase of 5 million cases over 2015.
- 90% of the cases in 2016 were in the WHO African Region (194 000), followed by the WHO South-East Asia Region (7%) and the WHO Eastern Mediterranean Region (2%)
- Fifteen countries accounted for 80% of all malaria cases globally (Fig. 6.2a). Nigeria accounted for the highest proportion of cases globally (27%), followed by the Democratic Republic of the Congo (10%), India (6%) and Mozambique (4%).
- Malaria deaths reached 445 000 in 2016, a similar number (446 000) to 2015.
- Malaria control in the WHO African Region has recorded progress, with a 42% reduction in case incidence and a 66% decline in the mortality rate between 2000 and 2016
- Total funding for malaria control and elimination reached an estimated US$ 2.7 billion in 2016. Contributions from governments of endemic countries amounted to US$ 800 million, representing 31% of funding.
Malaria is caused by single-celled microorganisms of the Plasmodium group .The disease is most commonly spread out by an infected female Anopheles mosquito .The disease is most commonly spread by an infected female Anopheles mosquito.The mosquito bite introduces the parasites from the mosquito’s saliva into a person’s blood. The parasites travel to the liver where they mature and reproduce. Five species of Plasmodium can infect and be spread by humans. Most deaths are caused by P. falciparum because P. vivax, P. ovale, and P. malariae generally cause a milder form of malaria. The species P. knowlesi rarely causes disease in humans. Malaria is typically diagnosed by the microscopic examination of blood using blood films, or with antigen-based rapid diagnostic tests. Methods that use the polymerase chain reaction to detect the parasite’s DNA have been developed, but are not widely used in areas where malaria is common due to their cost and complexity.
Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches.In severe cases it can cause yellow skin, seizures, coma, or death.Symptoms usually begin ten to fifteen days after being bitten by an infected mosquito.If not properly treated, people may have recurrences of the disease months later. In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistance disappears over months to years if the person has no continuing exposure to malaria
Malaria is an acute febrile illness. In a non-immune individual, symptoms usually appear 10–15 days after the infective mosquito bite. The first symptoms – fever, headache, and chills– may be mild and difficult to recognize as malaria. If not treated within 24 hours, P. falciparum malaria can progress to severe illness, often leading to death.
Children with severe malaria frequently develop one or more of the following symptoms: severe anaemia, respiratory distress in relation to metabolic acidosis, or cerebral malaria. In adults, multi-organ involvement is also frequent. In malaria endemic areas, people may develop partial immunity, allowing asymptomatic infections to occur.
The signs and symptoms of malaria typically begin 8–25 days following infection, but may occur later in those who have taken antimalarial medications as prevention. Initial manifestations of the disease—common to all malaria species—are similar to flu-like symptoms,and can resemble other conditions such as sepsis, gastroenteritis, and viral diseases.The presentation may include headache, fever, shivering, joint pain, vomiting, hemolytic anemia, jaundice, hemoglobin in the urine, retinal damage, and convulsions.
The classic symptom of malaria is paroxysm—a cyclical occurrence of sudden coldness followed by shivering and then fever and sweating, occurring every two days (tertian fever) in P. vivax and P. ovale infections, and every three days (quartan fever) for P. malariae. P. falciparum infection can cause recurrent fever every 36–48 hours, or a less pronounced and almost continuous fever.
Severe malaria is usually caused by P. falciparum (often referred to as falciparum malaria). Symptoms of falciparum malaria arise 9–30 days after infection. Individuals with cerebral malaria frequently exhibit neurologicalsymptoms, including abnormal posturing, nystagmus, conjugate gaze palsy (failure of the eyes to turn together in the same direction), opisthotonus, seizures, or coma.
In 2016, there were 215 million malaria cases that led to 460,000 deaths. Of these about two thirds (295,000) were children under five years of age. This translates into a daily toll of nearly 810 children under age 5. Most of these deaths occurred in sub-Saharan Africa. Since 2010, mortality rates among children under five have fallen by 34 per cent.
Malaria is an urgent public health priority. Malaria and the costs of treatment trap families in a cycle of illness, suffering and poverty. Today, 3.21 billion (almost half of the world population) are at risk. Since 2000, malaria has cost sub-Saharan Africa US$ 310 million each year for case management alone and it is estimated to cost up to 1.31 per cent of GDP in Africa.
Despite this heavy toll, major inroads have been made against the disease as a result of stepped-up funding and programming. Between 2000 and 2010, global investment for malaria control increased significantly and domestic investments have also increased annually. Funding increases have resulted in major advances against malaria. However, success is fragile and closely tied to sustained support and since 2010 there has been a plateau in the funding of the global malaria response. In 2016, the global total of international and domestic funding for malaria control and elimination was $2.72 billion – less than half of what is needed. In order to achieve the goal of a malaria-free world, annual spending requirements needs to more than double from the current level to $6.41 billion by 2020.