Peripheral gangrene in patients with severe falciparum malaria: report of 3 cases

Peripheral gangrene, characterized by distal ischemia of the extremities, is a rare complication in patients with falciparum malaria. Patients with this complication have generally undergone early amputation of the affected areas. In this report, we describe 3 adult Thai patients presented at the Hospital for Tropical Diseases, Bangkok, with high grade of fever ranged 6-9 days, jaundice, acute renal failure, respiratory failure, alteration of consciousness and shock. Two patients had gangrene developed at the lower extremities on day 1 of hospitalization and 1 patient had gangrene developed on day 3. Blood smears revealed hyperparasitemia with Plasmodium falciparum. These patients were diagnosed as having severe malaria with peripheral gangrene. The resolution of gangrene was successfully achieved by treatment with artesunate and conservative treatment in 2 of 3 cases.     

Predictive score of uncomplicated falciparum malaria patients turning to severe malaria

In acute uncomplicated falciparum malaria, there is a continuum from mild to severe malaria. However, no mathematical system is available to predict uncomplicated falciparum malaria patients turning to severe malaria. This study aimed to devise a simple and reliable model of Malaria Severity Prognostic Score (MSPS). The study was performed in adult patients with acute uncomplicated falciparum malaria admitted to the Bangkok Hospital for Tropical Diseases between 2000 and 2005. Total 38 initial clinical parameters were identified to predict the usual recovery or deterioration to severe malaria. The stepwise multiple discriminant analysis was performed to get a linear discriminant equation. The results showed that 4.3% of study patients turned to severe malaria. The MSPS = 4.38 (schizontemia) + 1.62 (gametocytemia) + 1.17 (dehydration) + 0.14 (overweight by body mass index; BMI) + 0.05 (initial pulse rate) + 0.04 (duration of fever before admission) - 0.50 (past history of malaria in last 1 year) - 0.48 (initial serum albumin) - 5.66. Based on the validation study in other malaria patients, the sensitivity and specificity were 88.8% and 88.4%, respectively. We conclude that the MSPS is a simple screening tool for predicting uncomplicated falciparum malaria patients turning to severe malaria. However, the MSPS may need revalidation in different geographical areas before utilized at specific places.     

Serum levels of interleukin-18 in patients with uncomplicated Plasmodium falciparum malaria

Interleukin (IL)-18, a newly discovered cytokine produced primarily by macrophages, has been shown to induce gamma interferon (IFN-gamma) production by natural killer cells, to induce the T helper type 1 response. To further elucidate the role of this cytokine in uncomplicated malaria caused by Plasmodium falciparum, serum levels of IL-18, and gamma interferon (IFN-gamma), determined by an immunoenzymatic assay, were analyzed in 40 adult patients, and in 15 healthy control subjects. A significant increase in serum levels of IL-18 was observed in patients with uncomplicated P. falciparum malaria on admission, whereas serum levels of IFN-gamma tended to increase although not significantly. Serum levels of IL-18 decreased three days later, but still remained significantly high, whereas IFN-gamma levels returned to normal levels compared to the controls. No significant correlation was found between parasitemia and serum levels of IL-18 and IFN-gamma. The increase of IL-18 levels during acute and recovery phases of uncomplicated P. falciparum malaria may reflect a proinflammatory role of IL-18 in these patients. An early and effective immune response regulated by proinflammatory Th1 cytokines, including tumor necrosis factor (TNF), interleukin (IL)-12, and possibly IFN-gamma may limit the progression from uncomplicated malaria to severe and life-threatening complications.