Malaria
Description:
Malaria is a serious infectious disease spread by certain mosquitoes. It is most common in tropical climates. It is characterized by recurrent symptoms of chills, fever, and an enlarged spleen. The disease can be treated with medication, but it often recurs. Malaria is endemic (occurs frequently in a particular locality) in many third world countries. Isolated, small outbreaks sometimes occur within the boundaries of the United States.
Signs and symptoms
Infectious Agent:
Malaria is produced by intraethrocytic parasites of the genus Plasmodium. Four plasmodia produce malaria in humans: Plasmodium falciparum, P. Vivax, P.ovale and P.malariae. The severity and characteristic manifestation of the disease are governed by the infecting species, the magnitude of the parasitemia, the metabolic effects of the parasite, the cytokines released as a result of the infection.
Prevention:
Several researchers are currently working on a malarial vaccine, but the complex life cycle of the malaria parasite makes it difficult. A parasite has much more genetic material than a virus or bacterium. For this reason, a successful vaccine has not yet been developed.Malaria is an especially difficult disease to prevent by vaccination because the parasite goes through several separate stages. One recent promising vaccine appears to have protected up to 60% of people exposed to malaria. This was evident during field trials for the drug that were conducted in South America and Africa. It is not yet commercially available.The World Health Association (WHO) has been trying to eliminate malaria for the past 30 years by controlling mosquitoes. Their efforts were successful as long as the pesticide DDT killed mosquitoes and antimalarial drugs cured those who were infected. Today, however, the problem has returned a hundred-fold, especially in Africa. Because both the mosquito and parasite are now extremely resistant to the insecticides designed to kill them, governments are now trying to teach people to take antimalarial drugs as a preventive medicine and avoid getting bitten by mosquitoes.A newer strategy as of late 2002 involves the development of genetically modified non-biting mosquitoes. A research team in Italy is studying the feasibility of this means of controlling malaria.Travelers to high-risk areas should use insect repellant containing DEET for exposed skin. Because DEET is toxic in large amounts, children should not use a concentration higher than 35%. DEET should not be inhaled. It should not be rubbed onto the eye area, on any broken or irritated skin, or on children's hands. It should be thoroughly washed off after coming indoors.Those who use the following preventive measures get fewer infections than those who do not:
Malaria is a serious infectious disease spread by certain mosquitoes. It is most common in tropical climates. It is characterized by recurrent symptoms of chills, fever, and an enlarged spleen. The disease can be treated with medication, but it often recurs. Malaria is endemic (occurs frequently in a particular locality) in many third world countries. Isolated, small outbreaks sometimes occur within the boundaries of the United States.
Signs and symptoms
- Recurrent chills
- Fever
- Profuse sweating
- Anemia
- Malaise
- Hepatomegaly
- Spleenomegaly
Infectious Agent:
Malaria is produced by intraethrocytic parasites of the genus Plasmodium. Four plasmodia produce malaria in humans: Plasmodium falciparum, P. Vivax, P.ovale and P.malariae. The severity and characteristic manifestation of the disease are governed by the infecting species, the magnitude of the parasitemia, the metabolic effects of the parasite, the cytokines released as a result of the infection.
Prevention:
Several researchers are currently working on a malarial vaccine, but the complex life cycle of the malaria parasite makes it difficult. A parasite has much more genetic material than a virus or bacterium. For this reason, a successful vaccine has not yet been developed.Malaria is an especially difficult disease to prevent by vaccination because the parasite goes through several separate stages. One recent promising vaccine appears to have protected up to 60% of people exposed to malaria. This was evident during field trials for the drug that were conducted in South America and Africa. It is not yet commercially available.The World Health Association (WHO) has been trying to eliminate malaria for the past 30 years by controlling mosquitoes. Their efforts were successful as long as the pesticide DDT killed mosquitoes and antimalarial drugs cured those who were infected. Today, however, the problem has returned a hundred-fold, especially in Africa. Because both the mosquito and parasite are now extremely resistant to the insecticides designed to kill them, governments are now trying to teach people to take antimalarial drugs as a preventive medicine and avoid getting bitten by mosquitoes.A newer strategy as of late 2002 involves the development of genetically modified non-biting mosquitoes. A research team in Italy is studying the feasibility of this means of controlling malaria.Travelers to high-risk areas should use insect repellant containing DEET for exposed skin. Because DEET is toxic in large amounts, children should not use a concentration higher than 35%. DEET should not be inhaled. It should not be rubbed onto the eye area, on any broken or irritated skin, or on children's hands. It should be thoroughly washed off after coming indoors.Those who use the following preventive measures get fewer infections than those who do not:
- Between dusk and dawn, remain indoors in well-screened areas.
- Sleep inside pyrethrin or permethrin repellent-soaked mosquito nets.
- Wear clothes over the entire body.
