The Symptoms of malaria depend very much on the amount of previous exposure to the disease and thus on the level of background immunity. In many parts of the tropics especially in Africa, transmission of falciparum malaria is intense and everyone is infected repeatedly. Children may get severe malaria in the first few years of life but gradually, with repeated infections most of them develop immunity. By the time they are adult they no longer show malaria symptoms as they did earlier. This hard-fought immunity of the survivors of malaria is easily lost if the subjects leave a Malarious area. In other areas of the world where transmission of the disease is less intense, symptoms develop at any age. Malaria patients usually present with anorexia, teeth-chattering chills, and high fever which occur exactly at the same time every one or two days. Others are joint weakness, diarrhea, hepatosplenomegaly, coke-colored urine, and in some cases vomiting and diarrhea. Headache, dizziness, and general body pains are also clinical symptoms of malaria.
There may be a feeling of tingling in the skin, particularly with malaria caused by P. falciparum. The classical symptom of Malaria is the cyclical occurrence of sudden coldness followed by rigor, then fever and sweating lasting 4-6 hours occurring every two days in P. Vivax and P. Ovale infections and every three days for P. Malariae. P. falciparum can have recurrent fever every 36-48 hours or less pronounced and almost continuous fever. for reasons that are poorly understood, but which may be related to high intracranial pressure, children with malaria frequently exhibit abnormal posturing, a sign indicating severe brain damage.
In P. Falciparum Malaria, severe and life-threatening conditions commonly arise. these cause dysfunction of vital organs such as the lungs, spleen, Kidneys, liver, and most famously the brain during cerebral malaria. severe anemia can also occur. These are associated with most of the mortality of acute malaria. Chronic infection with P. Malaria can also result in nephritic syndrome and this too can eventually be fatal.
Diagnosis of Malaria
Diagnosis of Malaria with certainty is on the identification of malaria parasites in the blood films of patients together with other symptoms associated with the disease. Diagnosis is parasitological and is made by examining thick blood films stained with field or Giemsa stains. however, in P. Falciparum infection the parasite containing erythrocytes tends to stick to the capillary endothelium and block the capillaries and thus circulation. This reduces the number of parasites found in the bloodstream and may lead to misdiagnosis or underestimation of the severity of the disease and its complications. Although species diagnosis can be made on thick films, it is also usually made on thin films stained with Leishman or Geimsa stains. This depends on the characteristics of the trophozoites, schizonts, and gametocytes. As a rule only ring forms and gametocytes are found in the peripheral blood in falciparum malaria unless the infection is severe. in which case, schizonts also appear.
In areas where microscopy is not feasible antigen detection tests are implored. another recent diagnostic technique in the fight against malaria is polymerase chain reaction (PCR) /. The technique is more accurate than microscopy but it is expensive and requires trained and specialized staff. Areas that cannot afford even simple laboratory tests often use a history of subjective fever as the indication to treat malaria.
Diagnosis of Malaria in Pregnancy
Diagnosis of malaria in Pregnancy is difficult to recognize and diagnose as the women are usually asymptomatic. Also the P. falciparum parasite sequesters in the placenta, the peripheral blood samples may not be detected in the infection therefore blood samples are usually collected from the placenta. the tests done include a blood smear test, rapid diagnostic test, polymerase chain reaction, and histological examination.