Endemic malaria is malaria that remains naturally and consistently present in a region because there are plentiful vectors for the disease, ensuring it will continue to be passed through society. Countries where malaria is endemic are primarily located in the tropics, and tend to be developing nations with limited public health infrastructure for fighting the disease. Fighting malaria worldwide has included a focus on addressing endemic malaria with the goal of eradicating it from these regions to eliminate natural reservoirs of the disease.
Malaria becomes endemic for several regions. This parasite requires mosquitoes of specific species as part of its lifecycle, and thus cannot become endemic in regions where these species are not supported. The tropics tend to be very hospitable to mosquitoes because of the warmth and ample supplies of standing water. In regions where mosquito control is limited, it can be difficult to prevent infected insects from biting humans and passing the infection on.
If the human population uses malaria prophylaxis, these bites are not a problem, as the parasites cannot survive in their bodies. Inconsistent or nonexistent use of prophylaxis, however, creates an avenue for malaria infections to set in, and infected patients will further the lifecycle of the parasite, with mosquitoes feeding on them and picking up infected blood, thus perpetuating the disease. People also travel, bringing the parasite with them as they go and creating an endless supply of new vectors.
Efforts at controlling endemic malaria include attempts to limit mosquito populations and contact between insects and humans, such as using pesticides, screening homes and beds to prevent the insects from getting inside, and dosing humans with compounds known to cause infertility in mosquitoes, thus preventing the insects from breeding. Provision of affordable malaria prophylaxis and treatment is another measure for addressing this problem. Travelers to regions with endemic malaria are usually advised to take prophylactic drugs so they do not carry the virus home with them.
In nations where the public health infrastructure is spotty and poorly supported, endemic malaria is difficult to fight. There may be regions where people have the virus under control, but in others it may be widespread and very common. As people travel between regions, they bring the parasite back and forth with them, creating new flareups of disease. Consistent and even malaria control policies also have to cross borders, as a rigorous program in one nation does little good if the country next door has an ineffectual program for malaria control in place.