Cryptosporidiosis should be designated as a tropical disease by the US Food and Drug Administration

摘要

Although the protozoan parasite Cryptosporidium spp. was recognized as a human pathogenin 1976 [1], it was only after a major outbreak in 1993 that sickened more than 400,000 andkilled 69 in Milwaukee, Wisconsin, United States of America [2], that its impact as a diarrhealdisease-causing pathogen began to be widely appreciated. Cryptosporidium has since been recognized as the most frequently identified pathogen in US waterborne outbreaks [3]. However,because otherwise healthy people recover spontaneously, it continues to be viewed in the USprimarily as an opportunistic pathogen causing chronic diarrhea in AIDS patients and otherimmunocompromised people. In 2013, publication of the first results from the Global EntericMulticenter Study (GEMS) highlighted the impact of this parasite among children in lowresource settings (LRS), including seven African and Asian countries. Cryptosporidium wasfound to be one of the three most important diarrhea-causing pathogens in children under 12months old and the most common cause of mortality due to moderate-to-severe diarrheaamong 12- to 23-month olds [4,5]. Subsequent epidemiological studies reinforced these findings, including MAL-ED (Etiology, Risk Factors and Interactions of Enteric Infections andMalnutrition and the Consequences for Child Health and Development) and more recent surveys by the Global Burden of Disease (GBD) and the GEMS-1A follow-on study to GEMS. Ateight Asian and African sites, the MAL-ED study found Cryptosporidium was among the fivemost important pathogens causing diarrhea in community clinics [6]. The GBD study estimated that globally Cryptosporidium is responsible for more than 44.8 million episodes of diarrhea and 48,000 deaths annually [7]. GEMS-1A confirmed and extended the findings fromGEMS by showing that Cryptosporidium was associated with a greater than 2-fold increasedrisk of death among 12- to 23-month olds with moderate-to-severe diarrhea [8].