Risk factors in HIV-associated diarrhoeal disease: the role of drinking water, medication and immune status

Do health risk perceptions motivate water - and health-related behaviour? A systematic literature review

Health-related risk perceptions are important determinants of health behaviours and components of behaviour change theories. What someone thinks or feels will motivate or hinder their intention or hesitancy to implement a certain behaviour. Thus, a perceived potential risk to our health and well-being can influence our health-promoting and/or health-seeking behaviour. We aimed to review and synthesize available peer-reviewed literature to better understand the links between water and health-related risk perceptions and behaviours. We conducted the first systematic review of peer-reviewed literature on risk perceptions and behaviours in the context of water and health, published between 2000 and 2021. A total of 187 publications met the inclusion criteria. We extracted data relating to study characteristics and categorized our results according to the major themes emerging from the literature, namely drinking water, sanitation, hygiene and wasterelated topics, health risk factors, diseases and mental health implications, and preventative measures. Our review shows that the literature has grown over the past twenty years, reporting information from different countries belonging to different income groups around the globe, conducted in various settings and contexts, among different target populations, from various disciplinary angles, using different methods, theories and approaches. Our review provides evidence of health risk perceptions determining behaviour particularly related to drinking water sources and water safety. Evidence on disease prevention, health seeking, variations and changes in perception and behaviour over space, geography, socioeconomic differences and time, and the relevance of cultural context is provided. Our review shows that risk perception studies are vital for WASH governance in terms of policy, raising awareness, education and behaviour change. In order to make risk perception and behaviour studies even more relevant to effective public health planning and health messaging, future research needs to increasingly focus on early culturally sensitive interventions and changes in perceptions and behaviours over time.

Cost-benefit analysis of point-of-use devices for health risks reduction from pathogens in drinking water

Microbial contamination of drinking water post-municipal treatment is difficult to predict as a risk factor for human health. One method to reduce morbidity or mortality from unpredictable exposures is through point-of-use (POU) treatment devices. The goal of this project was to assess the cost-benefit of POU water treatment at the tap in terms of protection from microbes in drinking water. This project estimated: (1) incidence of acute illness (AI), sequela, and mortality associated with waterborne pathogens; (2) illness reduction rates from using POU devices; and (3) healthcare cost reductions associated with POU devices. Infection rates and costs associated with 10 of the most common waterborne pathogens were identified and used to calculate national annual costs. We estimated 9M AI, 0.6M sequela, and 1,400 mortality cases that occur annually in the USA from these pathogens. The greatest cost-benefit was seen when considering the totality of disease burden reduction (AI, sequela, and mortality) including all pathogens at a national level and applying a 35% infection reduction, resulting in a total cost per averted disease case of $1,815. This study suggests that it is cost-beneficial to prevent water-related illness using POU devices.

Clinical and social determinants of diarrhoeal disease in a rural HIV/AIDS clinic, South Africa: a case-control study

Diarrhoeal diseases are a common cause of morbidity and are associated with mortality in HIV-infected populations. Little is known about the contribution of clinical and socio-environmental factors to the risk of diarrhoea in these populations in rural sub-Saharan Africa. We conducted a case-control study of people attending a rural HIV clinic with an episode of diarrhoea in Bushbuckridge, South Africa. Cases were defined as HIV-positive adults with symptoms of diarrhoea before or after initiation of antiretroviral therapy (ART). Controls without diarrhoea were randomly selected from clinic attendees. Structured questionnaires and case-file reviews were undertaken to describe clinical and socioenvironmental risk factors. We recruited 103 cases of diarrhoea from 121 patients meeting case definitions. Cases were more likely to be women (P = 0.013), aged over 45 years (P = 0.002), divorced or separated (P = 0.006), have limited formal education (P = 0.003), have inadequate access to sanitation facilities (P = 0.045), have water access limited to less than three days per week (P = 0.032) and not yet initiated on ART (P < 0.001). In multivariate analysis, diarrhoea remained associated with female gender (adjusted odds ratio [aOR]: 2.02, 95% CI 1.10-3.73), older age (aOR: 6.31, 95% CI 1.50-26.50), limited access to water (aOR: 2.66, 95% CI 1.32-5.35) and pre-ART status (aOR: 5.87, 95% CI 3.05-11.27). Clinical and socio-environmental factors are associated with occurrence of diarrhoeal disease among rural HIV patients in South Africa. Further intervention research is urgently needed, combining community- and clinic-based approaches, to improve access to water, sanitation and ART for rural areas with high HIV prevalence, along with structural interventions to address gender inequities.

Prevalence and impact of diarrhea on health-related quality of life in HIV-infected patients in the era of highly active antiretroviral therapy

OBJECTIVES

Before the introduction of highly active antiretroviral therapy (HAART), the majority of HIV-infected patients experienced diarrhea. The aims of this study were to compare the prevalence of diarrhea among HIV-infected and uninfected patients in the HAART era, and to evaluate the impact of diarrhea on health-related quality of life (HRQOL).

METHODS

Diarrheal symptoms experienced by 163 consecutive HIV-infected patients and 253 HIV-seronegative control subjects were ascertained using a validated questionnaire. The HRQOL of these patients was assessed using the Medical Outcomes Study (MOS) SF-36 and MOS-HIV Health surveys.

RESULTS

Among the 163 HIV-infected patients, the median CD4 cell count was 370 cells/mm and 150 individuals were taking HAART. Significantly, more HIV-infected subjects reported having 3 or more bowel movements daily within the past 7 days than did HIV-seronegative subjects (28.2% vs. 7.1%, P<0.001), even after adjusting for potential confounding variables (odds ratios=6.65; 95% confidence intervals, 3.36-13.17). In addition, diarrhea was significantly more common in HIV-infected patients than in control subjects when assessed by several other criteria. HIV-infected patients reported significantly worse HRQOL across all domains of the MOS SF-36 as compared with control subjects. Among HIV-infected patients, individuals with diarrhea had significantly worse HRQOL in nearly all domains of the MOS-HIV as compared with those without diarrhea.

CONCLUSIONS

Diarrhea remains an important clinical problem in HIV-infected patients and is associated with significant impairments in HRQOL. It is important that healthcare providers specifically evaluate their HIV-infected patients for diarrhea so that these symptoms may be optimally managed.

Hazards of healthy living: bottled water and salad vegetables as risk factors for Campylobacter infection

Campylobacter is the most common cause of bacterial gastroenteritis worldwide, yet the etiology of this infection remains only partly explained. In a retrospective cohort study, we compared 213 sporadic campylobacter case-patients with 1,144 patients with negative fecal samples. Information was obtained on food history, animal contact, foreign travel, leisure activities, medical conditions, and medication use. Eating chicken, eating food from a fried chicken outlet, eating salad vegetables, drinking bottled water, and direct contact with cows or calves were all independently associated with infection. The population-attributable fractions for these risk factors explained nearly 70% of sporadic campylobacter infections. Eating chicken is a well-established risk factor, but consuming salad and bottled water are not. The association with salad may be explained by cross-contamination of food within the home, but the possibility that natural mineral water is a risk factor for campylobacter infection could have wide public health implications.

Endemic cryptosporidiosis and exposure to municipal tap water in persons with acquired immunodeficiency syndrome (AIDS): a case-control study

BACKGROUND

In persons with acquired immunodeficiency syndrome (AIDS), Cryptosporidium parvum causes a prolonged, severe diarrheal illness to which there is no effective treatment, and the risk of developing cryptosporidiosis from drinking tap water in non-outbreak settings remains uncertain. To test the hypothesis that drinking tap water was associated with developing cryptosporidiosis, we conducted a matched case-control study among persons with AIDS in San Francisco.

METHODS

Among patients reported to the San Francisco AIDS Registry from May 1996 through September 1998, we compared patients who developed cryptosporidiosis to those who did not. Cases were individually matched to controls based on age, sex, race/ethnicity, CD4+ T lymphocyte count, date of CD4+ count, and date of case diagnosis. Population attributable fractions (PAFs) were calculated.

RESULTS

The study consisted of 49 cases and 99 matched controls. In the multivariable analysis with adjustments for confounders, tap water consumption inside and outside the home at the highest exposure categories was associated with the occurrence of cryptosporidiosis (inside the home: odds ratio (OR), 6.76; 95% CI 1.37-33.5, and outside the home: OR 3.16; 95% CI 1.23-8.13). The PAF was 85%; that is, the proportion of cases of cryptosporidiosis in San Francisco AIDS patients attributable to tap water consumption could have been as high as 85%.

CONCLUSIONS

Although the results from this observational study cannot be considered definitive, until there is more data, we recommend persons with AIDS, especially those with compromised immune systems, consider avoiding tap water.