Hiperparasitemia por Plasmodium falciparum como criterio diagnóstico de malaria grave. Fotografía médica.

Abstract

Paciente masculino de 37 años de edad, procedente de Santa Lucía, estado Miranda, quien refiere fiebre diaria no cuantificada de una semana de duración precedida de escalofríos y sucedida por diaforesis; concomitantemente cefalea, artralgias y lumbalgia. El paciente niega episodios maláricos anteriores. Es hospitalizado, encontrándose palidez cutánea, tos seca y hepatoesplenomegalia al examen físico. Se toma muestra de sangre periférica para realizar gota gruesa y extendido con coloración de Giemsa invertido y se observa a microscopía óptica (aumento de 1,000X, Nikon Eclipse E200®). Nótese la gran cantidad de trofozoítos anulares en la gota gruesa, mientras que en el extendido se observa un gametocito, varias formas appliqué y eritrocitos con poliparasitismo. Se evidencia aproximadamente un 20% de eritrocitos parasitados, con una parasitemia estimada de 98.850 parásitos/μL. Plasmodium falciparum es el agente etiológico más frecuentemente asociado a malaria grave, dentro de cuyos criterios diagnósticos destacan: hiperparasitemia, distress respiratorio, malaria cerebral, hipoglicemia, insufciencia renal, entre otros [1]. La hiperparasitemia es uno de los criterios de laboratorio para severidad; una parasitemia >10%, incluso en ausencia de hallazgos clínicos de severidad, indica malaria grave [2,3].

A 37 year-old male from Santa Lucía, Miranda state, complained of unquantifed daily fevers for the past week, preceded by chills and followed by profuse sweating; also, he complained of headaches, as well as pain in his joints and lower back. The patient denied any previous episodes of malaria. Physical examination during hospitalization showed pallor, dry cough and hepatosplenomegaly. A peripheral blood sample was taken for thick and thin smears with an inverted Giemsa’s stain and later observed under optical microscopy (1,000X magnifcation, Nikon Eclipse E200®). Note the large amount of ring-form trophozoites in the thick smear, while the thin smear shows a single gametocyte, many appliqué forms and red blood cells with polyparasitism. There are approximately 20% of infected red blood cells, with an estimated parasitemia of 98,850 parasites/μL. Plasmodium falciparum is the species most frequently associated to severe malaria, which includes the following as its most distinguished diagnostic criteria: hyperparasitemia, respiratory distress, cerebral malaria, hypoglycemia, kidney failure, among others [1]. Hyperparasitemia is one of the laboratory criteria for determining severity; a parasitemia >10%, even in the absence of clinical findings of severity, indicates severe malaria [2,3].