Preventing infectious diseases in long-term travelers to rural Africa

Knowledge and use of measures to reduce health risks by corporate expatriate employees in western Ghana

BACKGROUND

Expatriate corporate workers stationed in remote regions of developing countries with limited health care resources are at substantial risk for a variety of infectious diseases.

METHODS

A survey was carried out among expatriates working at a large power plant construction site in western Ghana in 1998 to evaluate their use of pretravel medical services, current knowledge, and behavioral practices in relation to food- and waterborne disease prevention, diarrhea, malaria, respiratory infections, alcohol use, and high-risk sexual activity. An anonymous, structured, and pretested questionnaire was used.

RESULTS

The response rate was 42 of 60 (70%). Most respondents were men (39 of 42, 93%) with previous international construction experience. Adherence to food and water safety recommendations decreased with time. Expatriates (15 of 23, 65%) from developed countries reported at least one episode of diarrhea, whereas no expatriates (0 of 9) from resource-poor countries reported diarrhea (p < 0.001). Use of malaria chemoprophylaxis deteriorated with increasing duration of time on the job site. None of the expatriates (0 of 9) who had been on the site for more than a year was still taking an antimalarial compared to those who had been there for 3 months or less (13 of 16) (p < 0.01). Forty-three percent (18 of 42) of the respondents reported having had a respiratory infection in the past 3 months. Only 38% (15 of 39) received preplacement education on human immunodeficiency virus (HIV) risk. A higher proportion of those who received pretravel HIV education used condoms always (4 of 5) than those who did not receive HIV education (1 of 5).

DISCUSSION

The use of health advice and preventive measures was generally low among the expatriate corporate survey respondents. Adherence to preventive measures declined with the increase in length of stay. Corporations need to develop appropriate health promotion strategies targeting their expatriates in developing countries.

Diarrhea and respiratory symptoms among travelers to Asia, Africa, and South and Central America from Scotland

Surveillance using admissions to hospital, while being useful, is a poor indicator of the real incidence of disease encountered by travelers. An alternative is self-reported illness among those who attended at a pretravel clinic prior to their travels. Estimates of incidence and risk factors were determined for attendees at a travel clinic in Scotland using a questionnaire. Analysis for risk factors was carried out for those travelers visiting countries in Africa, Asia, or South and Central America, who had traveled for 1 week or more and had returned between 1997 and 2001 (N= 4,856). Multivariate logistic regression was used to test the hypotheses that time abroad and age-group would be significant for both respiratory and diarrheal symptoms regardless of which of the three geographical areas are visited. From 2006 returned questionnaires (response rate = 41.3%), diarrhea and respiratory symptoms were reported by 44.2 and 16.8% of respondents, respectively; the incidence was significantly greater among travelers to Asia for both diarrheal (55.5%) and respiratory (23.7%) symptoms than among travelers to Africa (36.6 and 12.2%, respectively) or South and Central America (39.5 and 16.2%, respectively). For diarrhea, age was a highly significant risk factor for travelers to Asia, South and Central America, and Africa. Being a self-organized tourist/backpacker, traveling to Asia was associated with increased risk, while for Africa and South and Central America visiting family or friends was associated with a lower risk. For travelers to Asia, traveling to the Indian subcontinent was significantly associated with increased risk. The majority of travelers had an adverse event while traveling abroad, with diarrhea and respiratory conditions being especially common despite attending a travel clinic for advice prior to departure. However, the limitations of this surveillance-based strategy have highlighted the requirement for more research to understand more fully the issues of risk and incidence among travelers to high-risk destinations from Scotland.

Influence of hygiene on gastrointestinal illness among wilderness backpackers

BACKGROUND

Gastrointestinal illness is a common risk for wilderness travelers, even among those who consistently disinfect their water, yet the importance of hygiene has not been characterized.

METHODS

In a prospective surveillance study, 334 Appalachian Trail backpackers who hiked for at least 7 days in 1997 were interviewed. Upon completion of their hike, a written questionnaire was sent, addressing illnesses, water disinfection methods, and hygiene. Hygiene inquiries focused on the frequency of behaviors concerning handwashing and cleaning cookware.

RESULTS

Two hundred and eighty backpackers compiled 38,940 wilderness exposure days, with 56% (n=56) experiencing diarrhea. Diarrhea correlated with the frequency of drinking untreated surface water (relative risk (RR) 2.4, 95% confidence interval (CI) 1.0-4.7%, p5.03). Of those who consistently treated water, 45% suffered from diarrhea, whereas 69% of those who inconsistently treated water experienced diarrhea (RR 0.65, 95% CI 0.53-0.81%, p5.001). Hikers practicing "good hygiene", defined as handwashing post-defecation and cleaning cookware routinely, were less likely to ever experience diarrhea (RR 0.47, 95% CI 0.22-0.99, p5.04). Routine handwashing with soap and water after both urination and defecation reduced the risk of diarrhea (RR 0.11, 95% CI 0.04-0.31%, p,.001). In a case-control analysis of those experiencing diarrhea, decreased diarrhea was associated with routine consumption of multivitamins (RR 0.50, 95% CI 0.37-0.66%, p,.001), routine cleaning of utensils with warm, soapy water (RR 0.38, 95% CI 0.20-0.74%, p,.01), and post-defecation handwashing with soap and water (RR 0.61, 95% CI 0.39-0.93%, p5.006).

CONCLUSIONS

Lack of hygiene, specifically handwashing and cleaning of cookware, should be recognized as a significant contributor to wilderness gastrointestinal illness. Hikers should routinely disinfect water and avoid untreated surface water.