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Symptoms of malaria include fever, shivering, arthralgia (joint pain), vomiting, anemia (caused by hemolysis), hemoglobinuria, retinal damage, and convulsions. The classic symptom of malaria is cyclical occurrence of sudden coldness followed by rigor and then fever and sweating lasting for four to six hours, occurring every two days in P. vivax and P. ovale infections, while every three for P. malariae. P. falciparum can have recurrent fever every 36-48 hours or a less pronounced and almost continuous fever. For reasons that are poorly understood, but may be related to high intracranial pressure, children with malaria frequently exhibit abnormal posturing, a sign indicating severe brain damage.

Malaria has been found to cause cognitive impairments, especially in children. It causes widespread anemia during a period of rapid brain development and also direct brain damage. This neurologic damage results from cerebral malaria to which children are more vulnerable. Cerebral malaria is associated with retinal whitening, which may be a useful clinical sign in distinguishing malaria from other causes of fever (Smith et al., 1972).

Severe malaria is almost exclusively caused by P. falciparum infection, and usually arises 6-14 days after infection. Consequences of severe malaria include coma and death if untreated young children and pregnant women are especially vulnerable. Splenomegaly (enlarged spleen), severe headache, cerebral ischemia, hepatomegaly (enlarged liver), hypoglycemia, and hemoglobinuria with renal failure may occur. Renal failure may cause Mackwater fever, where hemoglobin from lysed red blood cells leaks into (he urine. Severe malaria can progress extremely rapidly and cause death within hours or days. In the most

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severe cases of the disease, fatality rates can exceed 20%, even with intensive care and treatment. In endemic areas, treatment is often less satisfactory and the overall fatality rate for all cases of malaria can be as high as one in ten. Over the longer term, developmental impairments have been documented in children who have suffered episodes of severe malaria (Carter et at., 2005).

Chronic malaria is seen in both P. vivax and P. ovale, but not in P. falciparum.

Here, the disease can relapse months or years after exposure, due to the presence of latent parasites in the liver. Describing a case of malaria as cured by observing the disappearance of parasites from the bloodstream can therefore be deceptive. The longest incubation period reported for P. vivax infection is 30 years. Approximately one in five of P. vivax malaria cases in temperate areas involve overwintering by hypnozoites i.e.relapses begin the year after the mosquito bite (Carter et at., 2005).

Occationally, fever, headache, chills or rigors, general weakness, vomiting, loss of appetite and profuse sweating. (uncomplicated) may progress rapidly to life threatening manifestations (severe). The clinical features of malaria vary from the asymptomatic to mild to severe disease. Particularly during pregnancy (a major public health problem) in tropical and subtropical regions and throughout the world. In most endemic areas of the world, pregnant women are the main adult risk group for malaria. Malaria during pregnancy has been most widely evaluated in Africa south of the Sahara where 90% of the global malaria burden occurs. The burden of malaria infection during pregnancy is caused chiefly by Plasmodiwn fateiparum, the most common malaria species in Africa. The impact of the other three human malaria parasites (P. vivax, P. malariae, and P. ovale) is less clear.

Every year at least 30 million pregnancies occur among women in malarious areas of

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Africa, most of whom reside in areas of relatively stable malaria transmission. The symptoms and complications of malaria during pregnancy differ with the intensity of malaria transmission and thus with the level of immunity the pregnant woman has acquired While these settings are presented as two distinct epidemiologic conditions, in reality the intensity of transmission and immunity in pregnant women occurs on a continuum, with potentially diverse conditions occurring within a country (Carter et at., 2005).

In areas of epidemic or low (unstable) malaria transmission, adult women have not acquired any significant level of immunity and usually become ill when infected with P.

falcipanan malaria. Pregnant women resident in areas of low or unstable malaria transmission are at a two- or threefold higher risk of developing severe disease as a result of malaria infection than are non-pregnant adults living in the same area. In these areas maternal death may result either directly from severe malaria or indirectly from malaria-related severe anaemia. In addition, malaria infection of the mother may result in a range of adverse pregnancy outcomes, including spontaneous abortion, neonatal death, and low birth weight ( Arora, 2001).

In areas of high and moderate (stable) malaria transmission, most adult women have developed enough immunity that, even during pregnancy, P. falciparum infection does not usually result in fever or other clinical symptoms in these areas; the principal impact of malaria infection is associated with malaria-related anaemia in the mother and with the presence of parasites in the placenta. The resultant impairment of foetal nutrition contributing to low birth weight is a leading cause of poor infant survival and development.

In areas of Africa with stable malaria transmission, P. falciparum infection during

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pregnancy is estimated to cause as many as 10000 maternal deaths each year, 8% to 14% of all low birth weight babies, and 3% to 8% of all infant deaths ( Arora, 2001).

Pregnant women are particularly vulnerable to malaria as pregnancy reduces a woman's immunity to malaria, making her more susceptible to malaria infection and increasing the risk of illness, severe anaemia and death. For the unborn child, maternal malaria increases the risk of spontaneous abortion, stillbirth, premature delivery and low birth weight - a leading cause of child mortality. The problem has long been neglected, but new approaches and commitment offer hope for reducing the burden of malaria in pregnancy and improving the health of mothers and newborns ( Arora, 2001).