DEFINITION
Malaria is a life-threatening mosquito-borne blood disease. The Anopheles mosquito transmits it to humansThe parasites in mosquitos that spread malaria belong to the Plasmodium genus. Over 100 types of Plasmodium parasite can infect a variety of species. Different types replicate at different rates, changing how quickly the symptoms escalate, and the severity of the disease.
Five types of Plasmodium parasite can infect humans. These occur in different parts of the world. Some cause a more severe type of malaria than others.
Once an infected mosquito bites a human, the parasites multiply in the host's liver before infecting and destroying red blood cells.
In some places, early diagnosis can help treat and control malaria. However, some countries lack the resources to carry out effective screening.
Currently, no vaccine is available for use in the United States, although one vaccine has a license in Europe.
In the early 1950s, advances in treatment eliminated malaria from the U.S. However, between 1,500 and 2,000 cases still occur each year, mostly in those who have recently traveled to malaria-endemic areas.
Symptoms
Doctors divide malaria symptoms into two categories: Uncomplicated and severe malaria.
A doctor would give this diagnosis when symptoms are present, but no symptoms occur that suggest severe infection or dysfunction of the vital organs.
This form can become severe malaria without treatment, or if the host has poor or no immunity.
Symptoms of uncomplicated malaria typically last 6 to 10 hours and recur every second day.
Some strains of the parasite can have a longer cycle or cause mixed symptoms.
As symptoms resemble those of flu, they may remain undiagnosed or misdiagnosed in areas where malaria is less common.
In uncomplicated malaria, symptoms progress as follows, through cold, hot, and sweating stages:
• a sensation of cold with shivering
• fever, headaches, and vomiting
• seizures sometimes occur in younger people with the disease
• sweats, followed by a return to normal temperature, with tiredness
In areas where malaria is common, many people recognize the symptoms as malaria and treat themselves without visiting a doctor.
In severe malaria, clinical or laboratory evidence shows signs of vital organ dysfunction.
Symptoms of severe malaria include:
• fever and chills
• impaired consciousness
• prostration, or adopting a prone position
• multiple convulsions
• deep breathing and respiratory distress
• abnormal bleeding and signs of anemia
• clinical jaundice and evidence of vital organ dysfunction
Severe malaria can be fatal without treatment.
Treatment
Treatment aims to eliminate the Plasmodium parasite from the bloodstream.
Those without symptoms may be treated for infection to reduce the risk of disease transmission in the surrounding population.
The World Health Organization (WHO) recommends artemisinin-based combination therapy (ACT) to treat uncomplicated malaria.
Artemisinin is derived from the plant Artemisia annua, better known as sweet wormwood. It rapidly reduces the concentration of Plasmodium parasites in the bloodstream.
Practitioners often combine ACT with a partner drug. ACT aims to reduce the number of parasites within the first 3 days of infection, while the partner drugs eliminate the rest.
Expanding access to ACT treatment worldwide has helped reduce the impact of malaria, but the disease is becoming increasingly resistant to the effects of ACT.
In places where malaria is resistant to ACT, treatment must contain an effective partner drug.
The WHO has warned that no alternatives to artemisinin are likely to become available for several years.
Prevention
Bite prevention – avoid mosquito bites by using insect repellent, covering your arms and legs, and using a mosquito net. Check whether you need to take malaria prevention tablets – if you do, make sure you take the right antimalarial tablets at the right dose, and finish the course..