Haemozoin is not associated with severe disease and poor outcome in kenyan children admitted to a Coastal District Hospital

Abstract

Malaria pigment (haemozoin) is the insoluble end product of haemoglobin digestion by the malaria parasite P Jalciparum. This is phagocytosed by the mononuclear and polymorphonuclear cells of the body which leads to the impairment of their immunological function as described in various in-vitro studies. The clinical association of haemozoin with severe malaria has been described but there has not been any study looking at the association of haemozoin with syndrome-directed approach to severity of illness and outcome due to any cause in children admitted to hospital. This retrospective cohort study describes the association of haemozoin with severity of illness of any cause and outcome comprising of various demographic, clinical and laboratory parameters in children admitted to Kilifi District Hospital over a period of one year. A Giemsa stained peripheral blood smear for malaria parasitaemia quantification was used to count pigment. Of the 4192 children satisfying the entry criteria 33.8% had pigment and 50.4% had parasitaemia on blood slide. Severe disease was seen in 34% and severe anaemia in 12.3%. Pathogenic bacteria from blood cultures were isolated in 6.2% with Streptococcus being the commonest organism. Salmonella was the 3rd commonest organism. Mortality was 5.8% of whom children with malaria comprised 16%. Of a subset of variables from the univariate analysis, a logistic regression model showed that severe anaemia (OR 2.8,95% CI 2.2-3.8), hyperlactataemia (OR 2.7, 95% CI 1.9-3.8) and Salmonella spp. bacteraemia (OR 5.0,95% CI 2.0-12.9) were independently associated with the presence of pigment. Malaria Pigment A sub-analysis, stratified by parasitaemia, showed that severe anaemia, a raised WBC count and Salmonella spp. bacteraemia were independently associated with the presence of pigment. A further analysis of children with a primary final diagnosis of malaria showed that coma, prostration, respiratory distress and hypoglycaemia were independently associated with poor outcome. There was no association between pigment and mortality or severity of illness in our analysis. However, pigment may have a role to play in the pathogenesis of malarial anaemia and invasive Salmonella infection.