Evolution of Seventh Cholera Pandemic and Origin of 1991 Epidemic, Latin America

Thirty single-nucleotide polymorphisms were used to track the spread of the seventh pandemic caused by Vibrio cholerae. Isolates from the 1991 epidemic in Latin America shared a profile with 1970s isolates from Africa, suggesting a possible origin in Africa. Data also showed that the observed genotypes spread easily and widely.     

Cholera in Brazil during 1991-1998: socioeconomic characterization of affected areas

The paper describes the trends in, and spatial patterns of, the incidence of cholera in Brazil from 1991 to 1998. During this period, 161,432 cases and 1,296 deaths from cholera were reported. The poorest (North and Northeast) regions of the country had the highest morbidity and mortality rates. The remaining regions had self-limited outbreaks. Seventy-eight percent of affected municipalities had populations of fewer than 30,000, and about 65% of them lived in rural areas. The affected municipalities of the North and Northeast regions had consistent indications of deprivation: average Human Development Index was 0.41, infant mortality rate 90.3%, average life expectancy 59.4 years, and adult illiteracy rate 46.5%. The epidemiological profile of the disease in Brazil highlights intra- and inter-regional socioeconomic differentials in the country and indicates the importance of planning and implementing public-health interventions and specific policies aimed at reducing health inequalities.     

Toward Cholera Elimination,Haiti

This study describes the apparent discontinuation of cholera transmission in Haiti since February 2019. Because vulnerabilities persist and vaccination remains limited, our findings suggest that case-area targeted interventions conducted by rapid response teams played a key role. We question the presence of environmental reservoirs in Haiti and discuss progress toward elimination.     

Cholera, travel, and infection control

The spread of cholera is a testimony to our inability to provide a consistently decent standard of living to the peoples of the world. Simply separating human sewage from potable water sources would curtail, if not eliminate, the disease. Even persons who acquire cholera would not die if they were given access to rehydration. American travelers should follow sensible food and water precautions, but need not curtail their travels to countries that have cholera.     

Cholera control on Guam, 2000

During April, 2000, the island of Pohnpei began experiencing an outbreak of cholera and during June and July of the same year four cases of cholera representing 3 separate introduction events were identified on Guam. Two of these events were associated with eating reef fish imported from Pohnpei. Following the imposition of a narrowly-focused ban on the importation of inshore seafood and processed food products from Pohnpei, no additional local or imported cases of cholera were detected on Guam.     

Understanding the Cholera Epidemic, Haiti

After onset of a cholera epidemic in Haiti in mid-October 2010, a team of researchers from France and Haiti implemented field investigations and built a database of daily cases to facilitate identification of communes most affected. Several models were used to identify spatiotemporal clusters, assess relative risk associated with the epidemic’s spread, and investigate causes of its rapid expansion in Artibonite Department. Spatiotemporal analyses highlighted 5 significant clusters (p<0.001): 1 near Mirebalais (October 16–19) next to a United Nations camp with deficient sanitation, 1 along the Artibonite River (October 20–28), and 3 caused by the centrifugal epidemic spread during November. The regression model indicated that cholera more severely affected communes in the coastal plain (risk ratio 4.91) along the Artibonite River downstream of Mirebalais (risk ratio 4.60). Our findings strongly suggest that contamination of the Artibonite and 1 of its tributaries downstream from a military camp triggered the epidemic.On October 21, 2010, the Haitian Ministry of Public Health and Population (MSPP) reported a cholera epidemic caused by Vibrio cholerae O1, serotype Ogawa, biotype El Tor (1). This epidemic was surprising as no cholera outbreak had been reported in Haiti for more than a century (1,2). Numerous media rapidly related the epidemic to the deadly earthquake that Haiti had experienced 9 months earlier. However, simultaneously, a rumor held recently incoming Nepalese soldiers responsible for importing cholera, along with accusations of illegal dumping of waste tank contents (3). A cholera outbreak was indeed reported in Nepal’s capital city of Kathmandu on September 23, 2010, shortly before troops left for Haiti (4,5). Two hypotheses then emerged to explain cholera in Haiti.Some researchers posited the transmission of an environmental strain to humans (6). Reasoning by analogy with cholera epidemiology in South Asia, they hypothesized that weather conditions, i.e., the La Niña phenomenon, might have promoted the growth of V. cholerae in its environmental reservoir (6). The second hypothesis suggested importation of the disease from a cholera-endemic country. The sequencing of 2 isolates of V. cholerae supported this second hypothesis by establishing an exogenous origin, probably from southern Asia or eastern Africa (7). Responding to a request from Haitian authorities to the French Embassy for the support of epidemiologists, we conducted a joint French–Haitian investigation during November 7–November 27, 2010, to clarify the source of the epidemic and its unusual dynamic.