Mosquitoes contract malaria when they feed on the blood of an infected human. The process typically occurs as follows:
Initial infection: When a person is infected with malaria, the malaria parasite (Plasmodium) enters their bloodstream. The parasite goes through several stages of development inside the human body.
Symptomatic stage: During the symptomatic stage, the infected person experiences malaria symptoms, such as fever, chills, headache, muscle aches, and fatigue. At this point, the malaria parasite is present in the person's bloodstream and can be detected through blood tests.
Asymptomatic stage: After the initial symptomatic stage, some individuals may enter an asymptomatic stage. This means they no longer show apparent symptoms, but the malaria parasite is still present in their bloodstream.
Mosquito transmission: When a mosquito feeds on an infected person, it ingests the malaria parasites along with the blood. The parasites then undergo further development inside the mosquito's body, eventually migrating to the mosquito's salivary glands.
Infected mosquito bites another person: When the same mosquito or another mosquito bites a different person to take a blood meal, it injects saliva containing the malaria parasites into the new host's bloodstream.
Transmission to a new host: The malaria parasites in the mosquito's saliva enter the new person's bloodstream, and the cycle continues.
The key point here is that during the asymptomatic stage, while the infected person may not show symptoms, the malaria parasites are still present in their bloodstream. Mosquitoes can pick up these parasites during a blood meal and then transmit them to another person they bite. This is why even people who have not had symptoms for a while can still play a role in the transmission of malaria to others if they are bitten by mosquitoes. Therefore, it's essential to take measures to prevent mosquito bites and control the spread of malaria in endemic areas.