Endemic Cholera in Rural Bangladesh, 1966–1980

Abstract

Since 1963, the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), formerly the Cholera Research Laboratory, has maintained a field station in Matlab to treat patients from a surveillance population of 240,000 who have cholera and other diarrheal diseases. Since 1966, the authors have analyzed hospital records of 7141 surveillance-area patients culture-positive for v. cholerae 01 to relate the seasonality, age and sex distribution, and geographic trends with hypotheses concerning transmission, immunity, and risk groups. From this review, they have found that: 1) children 2-9 years old and adult women are most commonly hospitalized for cholera; 2) V. cholerae 01 emerges simultaneously throughout the area of surveillance, with the early cases being of different phage types; 3) three patients were hospitalized twice for cholera compared with 29 expected on the basis of life-table analysis (p less than 0.01), suggesting that immunity to severe disease conferred by previous illness may be stable and long-lasting; 4) no constant relationship was found between the times of onset or peaks of the yearly cholera epidemic and the times of onset or peaks of the monsoon rains or river water levels; and 5) an outbreak of multiply antibiotic-resistant V. cholerae 01 infection documented in 1979 raises questions about the dissemination of resistance plasmids, antibiotic-use patterns, and the need for other drugs in addition to tetracycline. While little progress has been made in understanding the mode of transmission of v. cholerae 01, and in identifying practices for prevention, fluid therapy in this area has decreased the case fatality rate significantly and provides guidance for similar programs elsewhere.

Variation of Toxigenic Vibrio cholerae O1 in the Aquatic Environment of Bangladesh and Its Correlation with the Clinical Strains

“…Bangladesh, the number of cholera cases varies from year to year, but it flares into epidemics twice a yearonce in summer (March-April), and once in winter (September-December) (5,20). Vibrio cholerae survives in association with phytoplankton mainly blue green algae (7,8) and zooplankton (2,6).…”

Risk Factors for Pre-Post Monsoon Cholera Epidemics in Bangladesh from 1992-1994

“…For example, through research on seasonality and phage typing in Bangladesh, Glass et al (1982) According to Islam et al (1994) there are two types of environmental reservoirs that support the survival of V. cholerae in its association with blue-green algae: temporary and permanent. Temporary reservoirs are considered to be closed water systems (i.e., ponds and tanks), which help the pathogen to spread throughout the hwnan population by way of seasonal multiplication ofalgae bloom (Islam et al 1994).…”

“…The peak season for EI Tor usually occurs between September and December. For both cholera biotypes, a small peak occurred in the pre-monsoon months of March through June (Glass et al 1982). Longini et al (2002) studied cholera trends over a 33 year period in Bangladesh and found that despite the year to year fluctuations in cholera rates, the timing of the pre-and post-monsoon epidemics remain the same, regardless of the organism's biotype.…”

“…shows an open latrine hanging over a water body. Glass et al (1982) found that cholera was more common in villages that were not adjacent to the main river. Emch (1999) found that people living in flood-controlled areas were 2.47 times more likely to be hospitalized with cholera.…”

“…Several socioeconomic risk factors associated with cholera in rural Bangladesh have been identified. Glass et al (1982) found that predominately Hindu villages have higher cholera rates. One theory for this is that because fishing is primarily a Hindu occupation (Aziz 1994), there may be an association between fishing and cholera Cholera has been linked to fishing practices, possibly because of human's direct contact with contaminated water (Pollitzer 1959;Khan and Mosley 1967;McCormack et al 1969).…”