Which mosquitoes carry malaria

Plasmodium falciparum is the most deadly. Malaria transmission rates can differ depending on local factors such as rainfall patterns mosquitoes breed in wet conditions , the proximity of mosquito breeding sites to people, and types of mosquito species in the area. Some regions have a fairly constant number of cases throughout the year - these countries are termed "malaria endemic". In other areas there are "malaria seasons" usually coinciding with the rainy season.

Large and devastating epidemics can occur when the mosquito-borne parasite is introduced into areas where people have had little prior contact with the infecting parasite and have little or no immunity to malaria, or when people with low immunity move into areas where malaria cases are constant.

These epidemics can be triggered by wet weather conditions and further aggravated by floods or mass population movements driven by conflict.

Do all mosquitoes transmit malaria? The common first symptoms - fever, headache, chills and vomiting - usually appear 10 to 15 days after a person is infected. If not treated promptly with effective medicines, malaria can cause severe illness and is often fatal. Most cases and deaths are in sub-Saharan Africa. In , malaria was present in 91 countries and territories.

Early treatment of malaria will shorten its duration, prevent complications and avoid a majority of deaths. Because of its considerable drag on health in low-income countries, malaria disease management is an essential part of global health development. Treatment aims to cure patients of the disease rather than to diminish the number of parasites carried by an infected person. The best available treatment, particularly for P. However, the growing potential for parasite resistance to these medicines is undermining malaria control efforts see below.

You and your family can most effectively prevent malaria by taking all three of these important measures:.

Any traveler who becomes ill with a fever or flu-like illness while traveling, and up to 1 year after returning home, should immediately seek professional medical care. You should tell your health-care provider that you have been traveling in an area where malaria transmission occurs and ask to be tested for malaria infection.

It depends on what areas of that country you visited, how long ago you were there, and whether you ever had malaria. In general, most travelers to an area with malaria are deferred from donating blood for 1 year after their return.

People who used to live in countries where malaria transmission occurs cannot donate blood for 3 years. People diagnosed with malaria cannot donate blood for 3 years after treatment, during which time they must have remained free of symptoms of malaria.

Blood banks follow strict guidelines for accepting or deferring donors who have been in malaria-endemic areas. They do this to avoid collecting blood for transfusions from an infected donor.

In the United States during the period , there were 97 cases reported to CDC where people acquired malaria through a transfusion. Because of these control measures, transfusion-transmitted malaria is very rare in the United States and occurs at a rate of less than 1 per million units of blood transfused.

The disease should be treated early in its course, before it becomes serious and life-threatening. Several good antimalarial drugs are available, and should be taken early on.

The most important step is to go see a doctor if you are sick and are presently in, or have recently been in, an area with malaria, so that the disease is diagnosed and treated right away.

Malaria can be cured with prescription drugs. The type of drugs and length of treatment depend on the type of malaria, where the person was infected, their age, whether they are pregnant, and how sick they are at the start of treatment. Very rarely. Travelers who are taking effective malaria preventive drugs but who will be traveling for an extended period of time or who will be at higher risk of developing a malaria infection may decide, in consultation with their health-care provider, to take along malaria treatment medication referred to as a reliable supply in case they develop malaria while traveling.

If the traveler develops symptoms of malaria, they should immediately seek medical attention so that they can be examined and diagnosed appropriately. If they are diagnosed with malaria, they will then already have with them a reliable supply of an effective malaria treatment medicine to take.

Malaria self-treatment should begin right away if fever, chills, or other influenza-like illness symptoms occur and if professional medical care is not available within 24 hours. Self-treatment of a possible malarial infection is only a temporary measure and immediate medical care is important.

No, not necessarily. Malaria can be treated. If the right drugs are used, people who have malaria can be cured and all the malaria parasites can be cleared from their body.

However, the disease can continue if it is not treated or if it is treated with the wrong drug. Some drugs are not effective because the parasite is resistant to them. Some people with malaria may be treated with the right drug, but at the wrong dose or for too short a period of time. Two types species of parasites, Plasmodium vivax and P. People diagnosed with P. Another type of malaria, P. However, in general, if you are correctly treated for malaria, the parasites are eliminated and you are no longer infected with malaria.

Malaria typically is found in warmer regions of the world — in tropical and subtropical countries. Higher temperatures allow the Anopheles mosquito to thrive. Malaria parasites, which grow and develop inside the mosquito, need warmth to complete their growth before they are mature enough to be transmitted to humans.

Malaria occurs in more than countries and territories. Plasmodium falciparum predominates in Africa south of the Sahara, one reason why malaria is so severe in that area. A certain species of malaria called P.

Humans living in close proximity to populations of these macaques may be at risk of infection with this zoonotic parasite. Malaria transmission has been eliminated in many countries of the world, including the United States. However, in many of these countries including the United States Anopheles mosquitoes are still present.

Thus the potential for reintroduction of active transmission of malaria exists in many non-endemic parts of the world. All patients must be diagnosed and treated promptly for their own benefit but also to prevent the reintroduction of malaria. Biologic characteristics present from birth can protect against certain types of malaria. Two genetic factors, both associated with human red blood cells, have been shown to be epidemiologically important.

Persons who have the sickle cell trait heterozygotes for the abnormal hemoglobin gene HbS are relatively protected against P.

Because P. In general, the prevalence of hemoglobin-related disorders and other blood cell dyscrasias, such as Hemoglobin C, the thalassemias and G6PD deficiency, are more prevalent in malaria endemic areas and are thought to provide protection from malarial disease. Persons who are negative for the Duffy blood group have red blood cells that are resistant to infection by P. Since the majority of Africans are Duffy negative, P.

In that area, the niche of P. Other genetic factors related to red blood cells also influence malaria, but to a lesser extent. More on: Sickle Cell and Malaria. Acquired immunity greatly influences how malaria affects an individual and a community. After repeated attacks of malaria a person may develop a partially protective immunity. In areas with high P. As these antibodies decrease with time, these young children become vulnerable to disease and death by malaria. If they survive repeated infections to an older age years they will have reached a protective semi-immune status.

Thus in high transmission areas, young children are a major risk group and are targeted preferentially by malaria control interventions. In areas with lower transmission such as Asia and Latin America , infections are less frequent and a larger proportion of the older children and adults have no protective immunity. In such areas, malaria disease can be found in all age groups, and epidemics can occur. Anemia in young children in Asembo Bay, a highly endemic area in western Kenya.

Anemia occurs most between the ages of 6 and 24 months. After 24 months, it decreases because the children have built up their acquired immunity against malaria and its consequence, anemia. The mother had malaria, with infection of the placenta. Pregnancy decreases immunity against many infectious diseases.

Women who have developed protective immunity against P. Malaria during pregnancy is harmful not only to the mothers but also to the unborn children. The latter are at greater risk of being delivered prematurely or with low birth weight, with consequently decreased chances of survival during the early months of life.

For this reason pregnant women are also targeted in addition to young children for protection by malaria control programs in endemic countries. More on: Malaria During Pregnancy. Human behavior, often dictated by social and economic reasons, can influence the risk of malaria for individuals and communities. For example:. Human behavior in endemic countries also determines in part how successful malaria control activities will be in their efforts to decrease transmission.

The governments of malaria-endemic countries often lack financial resources. As a consequence, health workers in the public sector are often underpaid and overworked. They lack equipment, drugs, training, and supervision. The local populations are aware of such situations when they occur, and cease relying on the public sector health facilities. Conversely, the private sector suffers from its own problems.

Regulatory measures often do not exist or are not enforced. This encourages private consultations by unlicensed, costly health providers, and the anarchic prescription and sale of drugs some of which are counterfeit products. Correcting this situation is a tremendous challenge that must be addressed if malaria control and ultimately elimination is to be successful. The sickle cell gene is caused by a single amino acid mutation valine instead of glutamate at the 6th position in the beta chain of the hemoglobin gene.

Inheritance of this mutated gene from both parents leads to sickle cell disease and people with this disease have shorter life expectancy.

On the contrary, individuals who are carriers for the sickle cell disease with one sickle gene and one normal hemoglobin gene, also known as sickle cell trait have some protective advantage against malaria. As a result, the frequencies of sickle cell carriers are high in malaria-endemic areas. Most of this protection occurs between months of life, before the onset of clinical immunity in areas with intense transmission of malaria. Those who had the sickle cell trait HbAS had a slight survival advantage over those without any sickle cell genes HbAA , with children with sickle cell disease HbSS faring the worst.

Lancet ; Malaria is transmitted to humans by female mosquitoes of the genus Anopheles. Female mosquitoes take blood meals for egg production, and these blood meals are the link between the human and the mosquito hosts in the parasite life cycle. In contrast to the human host, the mosquito host does not suffer noticeably from the presence of the parasites. Map of the world showing the distribution of predominant malaria vectors.

Anopheles freeborni mosquito pumping blood Larger Picture. Sequential images of the mosquito taking its blood meal. The infection develops in the liver before re-entering the bloodstream and invading the red blood cells. The parasites grow and multiply in the red blood cells. At regular intervals, the infected blood cells burst, releasing more parasites into the blood. Infected blood cells usually burst every hours.