[Plasmodium vivax malaria in children and adolescents - epidemiological, clinical and laboratory features]

OBJECTIVE: Evaluation of epidemiological, clinical and laboratory features of Plasmodium vivax malaria in children and adolescents. METHODS: This study was carried out in the Malaria Program of the Evandro Chagas Institute (Belém, Pará), from January 1995 to November 1996. 100 children and adolescents with the diagnosis of P. vivax malaria (thick blood film) were randomly enrolled. A protocol was created to assess epidemiological, clinical and laboratory parameters of this pathology. RESULTS: Malaria occurred in both sexes, and had a prevailing incidence among adolescents (37%). Most of the children and adolescents (92%) had been infected in the State of Pará. Autochthonous cases in the metropolitan area of Belém accounted for 34 % of the sample. Primary infection was seen in 80% of the patients. Fever was the major onset clinical symptom (88%). A history of typical febrile paroxysm was recorded in only 25% of the casuistic. In the first day of treatment (D0) fever (97%), chills (91%), pallor (85%), splenomegaly (46%) and hepatomegaly (29%) were some of the clinical features observed. Pallor (clinical signal) was found to be significantly (p=0.0004) associated with anemia (hemoglobin rate). There was a high significant negative correlation (p=0.0001) between delay of diagnosis (mean 12,5 days) and hemoglobin values. Regarding parasitological examination, just children and adolescents with positive results to hookworms were significantly (p=0.0133, p=0.0075) more anemic than those who had a positive parasitological examination to other helminths and/or protozoa species. CONCLUSIONS: Malaria affected children and adolescents from both sexes. An emphasis on epidemiological and clinical data is an important tool to the precocious diagnosis of the disease. Delay on diagnosis made anemia worse.