Relapse

摘要: Plasmodium vivax is a major cause of febrile illness in endemic areas Asia, Central and South America, the horn Africa. P. infections are characterized by relapses malaria arising from persistent liver stages parasite (hypnozoites), which can be prevented currently only 8-aminoquinoline anti-malarials. Tropical relapse at approximately 3-week intervals if rapidly eliminated anti-malarials given for treatment, whereas temperate regions parts sub-tropics, either long incubation or long-latency period between – both cases approximating 8–10 months. The epidemiology different phenotypes has not been defined adequately despite obvious relevance to therapeutic assessment, control, elimination. number sporozoites inoculated anopheline mosquito an important determinant timing relapses. display remarkable periodicity explained. Evidence presented that proportion patients who have successive relatively constant factor activates hypnozoites leads regular interval systemic itself. It proposed areas, large population harbours latent activated such as falciparum malaria. This explains high rates following malaria, heterologous genotypes relapses, higher people living compared with artificial infection studies, and, facilitating recombination genotypes, contributes genetic diversity particularly low transmission settings. Long-latency may more widespread prevalent than thought. These observations implications assessment radical treatment efficacy control