Seasonal fluctuation of Plasmodium falciparum gametocytaemia

摘要: Two numerically minor components of Plasmodium falciparum prevalence--gametocytaemia and trophozoite densities greater than 99/500 white blood cells--displayed an annual cycle that reflected the seasonal abundance infective Anopheles dirus at a hyperendemic focus in Thailand, even though gross monthly prevalence for combined ages remained stable. Gametocyte rose more 300% within 30 d after capture dry season's first mosquito, about 8% until beginning monsoon 7 months later, then fell 60 to 2%. The number cases with high density trophozoites behaved similarly. These periodic fluctuations represented changes incidence, least half which appeared be due superinfection. Almost 49% all gametocyte carriers were older 14 years, but nearly 20/500 cells children. observations, as well calculated efficiency human infectivity, imply superinfection adults may contribute significantly transmission semi-immune populations.