ABSTRACT
BACKGROUND: Gastrointestinal (GI) illness is the most commonly reported health concern among Peace Corps Volunteers (PCVs) serving in Guatemala. This project identified water types and treatment and storage practices used by PCVs and measured select water quality parameters in their household water. METHODS: A survey about water types and practices was conducted of PCVs in Guatemala. The water type most frequently consumed in the household ("primary drinking water") and other water types present in the household ("secondary water") were tested for free chlorine residual (FCR) and for the presence of Escherichia coli and total coliforms. A negative binomial regression model was used to analyze data on incidence of self-reported GI illness. RESULTS: Tambo (commercially purified water in a 5-gal bottle) was the water type most frequently (64%) reported as primary drinking water in 39 PCV households. Most (74%) PCVs reported drinking water other than primary drinking water ≥1 day per week; the incidence rate of GI illness per PCV per month was significantly lower among PCVs who reported never consuming water other than primary drinking water compared to those who did (0.4 and 1.6 GI illnesses per PCV per month, respectively) (p < 0.05). E. coli was not detected in any primary drinking water sample, but was detected in 35% of secondary water samples. Total coliforms were detected in more than two-thirds of primary drinking water and secondary water samples. Nearly all water samples had an FCR of < 0.2 mg/L. CONCLUSIONS: Consuming primary drinking water exclusively likely contributes to reducing the rate of GI illness among PCVs. However, most PCVs reported drinking multiple water types, which may include contaminated secondary water types in the household. All water intended for consumption, including secondary sources within and outside the household, should be properly treated and safely stored.
ABSTRACT
BACKGROUND: Dengue is an arboviral disease estimated to cause 50-100 million infections each year in >100 tropical and subtropical countries. Urbanization, human population growth and expanded global travel have resulted in an increase in the incidence of dengue worldwide. International travellers to areas with endemic dengue are at risk of contracting dengue and US Peace Corps Volunteers are one specific group of long-term travellers who are exposed to environments where dengue can be contracted. METHODS: Cases of dengue among Peace Corps Volunteers, defined as clinically apparent infections with laboratory-confirmation by a positive NS1 antigen test, demonstration of IgM antibodies or by a 4-fold increase in IgG antibodies, between 1 January 2000 and 31 December 2014, reported to the Peace Corps' Epidemiologic Surveillance System were analyzed. RESULTS: Overall there were 1448 cases of dengue reported among Volunteers, with an incidence rate of 1.12 cases per 1000 Volunteer-months (95% CI 1.06-1.17). The highest rate of dengue among Volunteers was reported in the Caribbean region, with a rate of 5.51 cases per 1000 Volunteer-months (95% CI 4.97-6.10), followed by the East Asia/South Asia region (3.34, 95% CI 2.96-3.75) and Central America (2.55, 95% CI 2.32-2.79). The rate of dengue peaked in 2007, 2010 and 2013. Each peak year was followed by a trough year. CONCLUSIONS: Globally, there appears to be a 3-year cyclical pattern of dengue incidence among Volunteers, with differences by region. Dengue continues to be a priority health issue for travellers to endemic areas, and enhanced surveillance of dengue among international travellers may result in improved patient education and prevention efforts.