K. Bhuvaneswari*, L. Mohini Swetha, M. Ramesh,B. Mounika, T. Anantha Lakshmi, B. Brahmaiah, Sreekanth Nama
Priyadarshini institute of pharmaceutical education & research (PIPER)
Vatticherukuru (M), Guntur, A.P, India
Malaria, transmitted by female Anopheles mosquitoes biting during night time, from sunset to dawn, is the most important parasitic disease worldwide. Five species (Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, Plasmodium malariae and, as recently discovered, Plasmodium knowlesi) can cause disease in humans. At first, malaria symptoms may be unspecific, including joint pain, asthenia and abdominal pain; followed by high fever, shivering, and anorexia and vomiting. The most severe form is caused by Plasmodium falciparum. The importance of behavioral preventive measures (bed nets, repellents, etc.), adequate chemoprophylaxis and increase the awareness of Pathophysiology, health measures of disease to be taken. Coming to the mainstay of malaria diagnosis has been the microscopic examination of blood, utilizing blood films for confirmation of malaria and further fallow up sanitation and chemoprophylaxis of the disease.
Key words: Malaria, Anopheles mosquitoes, chemoprophylaxis
Malaria is a parasitic disease transmitted by parasites that cause malaria Plasmodiumovale, P. malariae, P. knowlesi, P. vivax, and P. falciparum. The last 2 are the most common, primarily, malaria is an infection of the red blood cells, causing recurring fever of sudden on set. Malaria caused by P. falciparum is lifethreatening and can cause multiple organ damage, coma and death.
Malaria is spread by female Anopheles mosquitoes. The parasite enters the body in mosquito saliva when a person is bitten by an infected mosquito. The parasite first infects the liver where it begins to multiply. After some days, the resulting parasites are released into the blood stream to infect the red blood cells, where they continue to multiply, eventually bursting the red blood cells and further infecting others. If they reach high numbers they may cause severe disease or even death. Some of the parasites in the red blood cells develop into the sexual stages (gametocytes).If these stages are ingested when a mosquito bites an infected person, they develop in the gut of the mosquito for 10 –14 days, and then enter the salivary glands, ready for the next bite. Malaria is found throughout the tropical and subtropical regions of the world. Areas of high transmission are found predominantly in rural areas in South America (e.g. Brazil), south east Asia (e.g. Thailand, Indonesia and East Timor), Western Pacific (Papua New Guinea, Solomon Islands and Vanuatu) and throughout sub-Saharan Africa.
The last case of locally acquired malaria in the Northern Territory was in 1962 and Australia was declared free of malaria by the World Health Organisation (WHO) in 1981. However, a number of species of Anopheles mosquito exist in the NT and the malaria parasite could be re-introduced into local mosquitoes if infected travellers from overseas are bitten here. The outcome of a malaria infection is a consequence of interactions between host, parasite and environmental factors. As such attempts to correlate out come with a single immunological parameter often results spurious associations that do not hold in different circumstances. This situation is exacerbated by the lack of natural animal models for human malaria from which observations could reliably be extrapolated consequently; much of our understanding of malaria immunity is based on extrapolation of in vitro observations or deduced from phenomenological observations. As is the case with immunity to other infections, immunity to malaria is the result of a combination of genetic resistance, non-adaptive immunity, and acquired or adaptive immunity. This chapter will mainly focus on immunity to Plasmodium falciparum malaria because it accounts for largest proportion of disease and practically all malaria mortality.