Screen of traditional soup broths with reported antipyretic activity towards the discovery of potential antimalarials.

OBJECTIVE: The global impact of artemisinin-based combination therapies on malaria-associated mortality and their origins in ancient Chinese medicine has heightened interest in the natural discovery of future antimalarials. METHODS: A double-blind study to identify potential ingredients with antimalarial activity from traditional remedies with reported antipyretic properties. Recipes of clear broths, passed down by tradition in families of diverse ethnic origin, were sourced by school children. Broths were then tested for their ability to arrest malaria parasite asexual growth or sexual stage development in vitro. Clear broth extract was incubated with in vitro cultures of Plasmodium falciparum asexual or mature sexual stage cultures and assayed for parasite viability after 72 hours. RESULTS: Of the 56 broths tested, 5 were found to give >50% in vitro growth inhibition against P. falciparum asexual blood stages, with 2 having comparable inhibition to that seen with dihydroartemisinin, a leading antimalarial. Four other broths were found to have >50% transmission blocking activity, preventing male parasite sexual stage development. After unblinding, two active broths were found to be from siblings from different classes, who had brought in the same vegetarian soup, demonstrating assay robustness. CONCLUSIONS: This screening approach succeeded in finding broths with activity against malaria parasite in vitro growth, arising from complex vegetable and/or meat-based broths. This represented a successful child education exercise, in teaching about the interface between natural remedies, traditional medicine and evidence-based drug discovery.

Tolerance May Be More Appropriate Than Immunity When Describing Chronic Malaria Infections.

Adults who have not grown up in a malaria-endemic area may experience severe malaria soon after entering a malarious area. Such mortality is usually limited to a short period of time (months), after which they are thought to be "immune." Such anti-disease immunity may be more accurately considered as tolerance. Malaria rates of British soldiers during the Second World War reflected their time with suppressed infections and the transmission levels. Black workers from non-endemic areas on the Panama Canal experienced higher initial mortality and infection rates than co-located white workers for Plasmodium falciparum, whereas the known genetic resistance of blacks to Plasmodium vivax reversed these rates. The ethnic differences observed in malaria rates may have more to do with acquired tolerance than genetic resistance. Long-term (years) sub-patent infections may maintain host tolerance, and elimination of malaria infections may place these adults at subsequent risk of severe malaria.

Subdural haematoma in Plasmodium falciparum and Plasmodium vivax mixed infection presenting multiple clinical complications.

A 40-year-old man was admitted to hospital with a 5 day history of fever, restlessness and altered sensorium. Peripheral blood smears showed a Plasmodium vivax and Plasmodium falciparum mixed infection as revealed by the presence of rings, schizonts and gametocyte forms of the parasites. The patient soon became unconscious due to subdural haematoma (SDH) associated with disseminated intravascular coagulation and thrombocytopenia. Immediate intervention with a right fronto-parieto temporal craniectomy, evacuation of the SDH and intravenous quinine administration resulted in the patient's complete recovery within 8 days of admission, and he was discharged in good clinical condition.