Hemolysis after Oral Artemisinin Combination Therapy for Uncomplicated Plasmodium falciparum Malaria.

Episodes of delayed hemolysis 2-6 weeks after treatment of severe malaria with intravenous artesunate have been described. We performed a prospective observational study of patients with uncomplicated malaria to investigate whether posttreatment hemolysis also occurs after oral artemisinin-based combination therapy. Eight of 20 patients with uncomplicated malaria who were given oral artemisinin-based combination therapy met the definition of posttreatment hemolysis (low haptoglobin level and increased lactate dehydrogenase level on day 14). Five patients had hemolysis persisting for 1 month. Patients with posttreatment hemolysis had a median decrease in hemoglobin level of 1.3 g/dL (interquartile range 0.3-2.0 g/dL) in the posttreatment period, and patients without posttreatment hemolysis had a median increase of 0.3 g/dL (IQR -0.1 to 0.7 g/dL; p = 0.002). These findings indicate a need for increased vigilance for hemolytic events in malaria patients, particularly those with predisposing factors for anemia.

Post-treatment haemolysis is common following oral artemisinin combination therapy of uncomplicated malaria in travellers.

BACKGROUND: Artemisinin-based combination therapy (ACT) for the treatment of malaria is highly effective, well tolerated and safe. Episodes of delayed haemolysis occur in up to 57.9% of patients with severe malaria treated with intravenous artesunate, mainly caused by 'pitting' of infected red blood cells in the spleen and the delayed loss of these once-infected RBCs (oiRBCs). Several reports indicate that post-treatment haemolysis (PTH) also occurs in uncomplicated malaria treated with oral ACT, calling for systematic investigation. METHODS: A prospective observational study to identify the incidence of PTH after oral ACT, defined as increased lactate dehydrogenase activity and low haptoglobin level on Day 14 after treatment. Patients were enrolled at two study centres in Germany and Italy. Study visits took place on Days 1, 3, 7, 14 and 28. Laboratory investigations included extended clinical routine laboratory tests, quantitative PfHRP2, anti-RBC antibodies and oiRBCs. The state of semi-immunity to malaria was assessed from childhood and ongoing exposure to Plasmodium spp. as per patient history. RESULTS: A total of 134 patients with uncomplicated malaria and 3-day ACT treatment were recruited. Thirty-seven (37.4%) of 99 evaluable patients with Pf and none of 9 patients with non-Pf malaria exhibited PTH on d14. Patients with PTH had higher initial parasitaemia, higher oiRBC counts on d3 and a 10-fold decrease in oiRBCs between d7 and d14 compared with patients without PTH. In patients with PTH, loss of haemoglobin was 4-fold greater in non-Africans than in Africans (-1.3 vs -0.3 g/dl). Semi-immune African patients with PTH showed markedly increased erythropoiesis on d14 compared with not semi-immune African and non-African patients with PTH. CONCLUSIONS: PTH is common in patients with uncomplicated malaria and oral ACT. While the observed loss of haemoglobin will often not be clinically relevant, it could aggravate pre-existing anaemia, warranting follow-up examinations in populations at risk.

Uncommon manifestation of a mixed-species malaria infection: cryptic falciparum malaria in a traveler with successfully treated tertian malaria.

We report a case of falciparum malaria in a traveler 9 days after successful treatment of ovale malaria. The underlying, cryptic mixed-species infection was primarily undetectable with standard laboratory diagnostics. This case highlights the limitations of these tests and the unpredictability of typical incubation periods in the individual case.

High frequency of multidrug-resistant Mycobacterium tuberculosis isolates in Georgetown, Guyana.

Emergence of multidrug-resistant (MDR) Mycobacterium tuberculosis isolates constitutes a threat to public health worldwide. This study aimed at acquiring first epidemiological data for Guyana. Thirty-six M. tuberculosis isolates from patients of the Georgetown Chest Clinic were subjected to susceptibility testing on solid agar and in broth media. Resistance to at least one first-line drug was observed in 8 (22.2%, 95% confidence interval 8.3-36.1%) and simultaneous resistance to rifampicin and isoniazid (MDR) in 4 (11.1%, 95% confidence interval 0.6-21.6%) of the 36 isolates. The risk of infection with resistant isolates was significantly related to earlier antituberculosis therapy (P=0.040). These data indicate a high proportion of resistant M. tuberculosis isolates in Guyana and call for the implementation of control strategies based on an improved laboratory diagnosis of TB.