What is malaria?
Malaria is a disease of the blood that is transmitted  to  people  by  infected mosquitoes. Malaria is very common throughout the world.

What  is  the  infectious  agent  that causes malaria? Malaria  is  caused  by  any  one  of  four species of one-celled parasites, called Plasmodium. The parasite is spread to people  by the female Anopheles mosquito,  which feeds on human blood. Although  four  species  of malaria  parasites  can  infect  humans and cause illness, only malaria caused by  Plasmodium   falciparum   is   potentially life-threatening.

Where is malaria found?
Malaria  transmission  occurs  in  large areas  of  Central  and  South  America, sub-Saharan  Africa,  the  Indian subcontinent,  Southeast  Asia,  the Middle East, and Oceania.

How is malaria spread?
A person gets malaria from the bite of an  infected  female  mosquito. The mosquito bite injects young forms of the malaria parasite into the person's blood. The  parasites  travel  through the person's bloodstream to the liver, where they grow to their next stage of development.  In  6  to  9  days,  the parasites leave the liver and enter the bloodstream  again. They  invade  the red  blood  cells,  finish growing, and begin to multiply quickly. The number of  parasites  increases  until  the  red  blood cells burst, releasing thousands of  parasites into  the  person's bloodstream. The parasites attack other red blood cells, and the cycle of infection  continues, causing  the common  signs  and  symptoms  of malaria.

When  a  non-infected  mosquito  bites an  infected  person,  the  mosquito sucks  up  parasites  from  the  person's blood. The mosquito is then infected with  the  malaria  parasites.  The parasites go through several stages of growth  in  the  mosquito.  When  the mosquito  bites  someone  else,  that person  will  become  infected  with malaria  parasites,  and  the  cycle  will begin again. Malaria  parasites  can  also  be transmitted  by  transfusion  of  blood from an infected person or by the use of  needles  or  syringes  contaminated with the blood of an infected person.

What are the signs and symptoms of malaria?
People  with  malaria  typically  have cycles  of  chills,  fever,  and  sweating that recurs  every 1, 2, or 3 days. The attack of the malaria parasites on the person's  red  blood  cells  makes  the person's  temperature  rise  and  the person  feel  hot.  The  subsequent bursting of red blood cells makes the person  feel  cold  and  have  hard, shaking  chills.  Nausea,  vomiting,  and diarrhea often go along with the fever. The destruction of red blood cells can also cause jaundice (yellowing of  the skin or whites of the eyes) and anemia.

 
How soon after exposure do symptoms appear?
The time between a mosquito bite and the  start  of  illness  is  usually  7  to  21 days,  but  some  types  of  malaria parasites  take  much  longer  to  cause symptoms. When infection occurs by blood  transfusion,  the  time  to  the start  of  symptoms  depends  on  the number of parasites in the transfusion.

 
How is malaria diagnosed?
Malaria is diagnosed by a blood test to check for parasites.
 
Who is at risk for malaria?
Anyone  who  lives  in  or  travels  to  a country  where  there  are  malaria- infected people and mosquitoes is at risk.

What complications  can  result  from malaria?
Malaria  caused  by  Plasmodium falciparum  can  cause  kidney  or  liver failure,  coma,  and  death.  Although infections with other malaria parasites  cause  less  serious  illness,
parasites  can  remain  inactive  in  the liver  and  cause  a  reappearance  of
symptoms months or even years later.

What is the treatment for malaria?
The treatment for malaria depends on where  a  person  is  infected  with  the disease.  Different  areas  of  the  world have  malaria  types  that  are  resistant to  certain  medicines.  The  correct drugs for each type of malaria must be  prescribed by a doctor.
Infection with Plasmodium falciparum is a medical emergency. About 2% of persons  infected  with  falciparum malaria  die,  usually  because  of delayed treatment.

How common is malaria?
Worldwide, an estimated 200 million to 300 million malaria infections occur each year, with 2 million to 3 million deaths.  Most  deaths  are  from infection with plamodium falciparum.

How can malaria be prevented?
1. Avoid mosquito bites -- Avoiding the bites of Anopheles mosquitoes is the best  way  to  prevent  infection. Because  Anopheles  mosquitoes  feed at  night,  malaria  transmission
happens  mainly  between  dusk  and dawn.

Use insect repellent on exposed skin. The most effective repellents contain 20%  to 35% DEET (N,N - diethylmethyltoluamide). Follow application  instructions  carefully
when using these products. Spray  living  and  sleeping  areas  with insecticide.

Use a bednet when sleeping in a room that is not screened or air conditioned. For extra protection, treat the bednet with the insecticide permethrin.

Seek medical help in case of illness -- Symptoms  of  malaria  can  be  mild. Travelers  should  suspect  malaria  if they experience an unexplained fever while  in  or  after  returning  from  an area  where  malaria  is  common. Persons  with  suspected  malaria should get medical help right away.