Risk factors for trachoma in Mali

OBJECTIVES: Prior to commencing a campaign to eliminate blinding trachoma in Mali, a national disease prevalence survey was conducted from March 1996 to June 1997. The prevalence of trachoma was estimated and potential risk factors were studied. METHODS: In each of Mali's seven regions (excluding the capital Bamako), a sample of 30 clusters was taken from the general population, in accordance with the principle of probability proportional to the size of the community. All children under 10 years of age were examined. The simplified clinical coding system proposed by the World Health Organization was used. The position of each village was established and subsequently related to the nearest meteorological station. Socioeconomic and environmental information was collected at both village and household level. The mother or caretaker of each child was questioned about availability and use of water for washing the child. At the time of examination, facial cleanliness and the presence of flies on the face were noted. RESULTS: A total of 15,187 children under 10 years of age were examined. The prevalence of active trachoma (follicular [TF] or intense trachoma [TI]) was 34.9% (95% CI : 32.3-37.6) and the prevalence of TI was 4.2% (95% CI : 3.5-5.0). Aridity/environmental dryness appears to be a risk factor influencing the current geographical distribution of trachoma. Small villages had considerably higher trachoma prevalence than their larger neighbours. The proximity of a medical centre and the existence of social organizations such as a women's association were associated with lower levels of trachoma. Crowded living conditions increased the risk. Using a monetary marker of wealth, we observed a linear inverse relation between wealth and trachoma prevalence. The presence of a dirty face was strongly associated with trachoma (odds ratio [OR] = 3.67) as was the presence of flies on the child's face (OR = 3.62). Trachoma prevalence increased with distance to a water source. Disease prevalence decreased with a higher frequency of both face washing and bathing. CONCLUSIONS: Of all the risk factors examined, facial cleanliness had the strongest association with the prevalence of trachoma. This was followed by the presence of flies on the child's face. Both face washing and bathing showed beneficial effects. Socioeconomic factors such as wealth were significantly explanatory. It is likely that hygiene education and fly control by environmental improvement could have a very significant impact on the prevalence of trachoma in Mali.     

Risk factors for active trachoma in children and trichiasis in adults: a household survey in Amhara Regional State, Ethiopia

Identification of risk factors is essential for planning and implementing effective trachoma control programmes. We aimed to investigate risk factors for active trachoma and trichiasis in Amhara Regional State, Ethiopia. A survey was undertaken and eligible participants (children aged 1-9 years and adults aged 15 years and above) examined for trachoma. Risk factors were assessed through interviews and observations. Using ordinal logistic regression, associations between signs of active trachoma in children and potential risk factors were explored. Associations between trichiasis in adults and potential risk factors were investigated using conventional logistic regression. A total of 5427 children from 2845 households and 9098 adults from 4039 households were included in the analysis. Ocular discharge [odds ratio (OR)=5.9; 95% CI 4.8-7.2], nasal discharge (OR=1.6; 95% CI 1.3-1.9), thatch roof in household (OR=1.3; 95% CI 1.0-1.5), no electricity in household (OR=2.4; 95% CI 1.3-4.3) and increasing altitude (Ptrend<0.001) were independently associated with severity of active trachoma. Trichiasis was associated with increasing age (ORper 5 year increase=1.5; 95% CI 1.4-1.7), female gender (OR=4.5; 95% CI 3.5-5.8), increasing prevalence of active trachoma in children (Ptrend=0.003) and increasing altitude (Ptrend=0.015).     

Risk factors for trachoma: 6-year follow-up of children aged 1 and 2 years

The authors investigated the long-term stability of risk factors in predicting the presence of active trachoma and severe inflammatory trachoma in 176 children in Kongwa, Tanzania, who were aged 1 and 2 years in 1989 and were available for follow-up in 1995. Familial cattle ownership, living more than 2 hours away from a water source, and facial cleanliness at both time points were associated with the presence of active trachoma at both time points (odds ratio (OR) = 2.58, 95% confidence interval (CI): 1.15, 5.79; OR = 3.07, 95% CI: 1.23, 7.64; and OR = 0.52, 95% CI: 0.26, 1.03, respectively). An association of familial cattle ownership with facial cleanliness and water accessibility was observed. Having a clean face at both time points was associated with lower odds of active trachoma at both time points for children in non-cattle-herding families (OR = 0.40, 95% CI: 0.18, 0.87). Living more than 2 hours away from a water source at both time points increased the odds of active trachoma at both time points in children of cattle-herding families (OR = 8.00, 95% CI: 1.99, 32.10). Noticeably, severe inflammatory trachoma at baseline predicted mortality in children from villages in which trachoma was less common (OR = 3.75, 95% CI: 1.09, 12.98). The results suggest that risk factor reduction could diminish persistent disease.     

Risk factors for severe respiratory syncytial virus infection leading to hospital admission in children in the Western Region of The Gambia

BACKGROUND: Acute lower respiratory tract infections (ALRI) are the major cause of mortality and morbidity in young children worldwide. Respiratory syncytial virus (RSV) infection is the most important viral cause of severe ALRI but only a small proportion of children infected with this virus develop severe disease. To identify possible risk factors for severe RSV infection leading to hospital admission we have carried out a case-control study of Gambian children with RSV infection admitted to hospital. METHODS: In all, 277 children admitted to three hospitals in the Western Region of The Gambia with lower respiratory tract infection due to RSV were compared with 364 control children matched for age and location of residence who had not been admitted to hospital with an ALRI during the RSV season. A detailed questionnaire covering a wide range of potential social, environmental and nutritional risk factors was administered to the child's guardian. RESULTS: Cases came from larger or more crowded compounds than controls; increased risk was particularly associated with greater numbers of children in the age group 3-5 years living in the compound (odds ratio [OR] for > or =2 children in the age group 3-5 years = 9.1, 95% CI: 3.7-28). Cases were more likely to have a sibling who had died (OR = 3.4, 95% CI: 1.7-7). Controls were more likely to have been exposed to smoke from cooking fires (OR for the mother of cases cooking at least once daily = 0.31, 95% CI: 0.14-0.7). Other protective factors were father's nationality and some professions. Vegetables were included in the diet of controls more frequently than in that of cases (OR = 0.16, 95% CI: 0.06-0.46). Mothers of cases complained of asthma more frequently than mothers of controls, but the number of asthmatic mothers was small (4.2 versus 0.5%, P = 0.05). CONCLUSIONS: Risk factors for severe RSV infection identified in this study are not amenable to public health interventions. Prevention of severe infection is likely to require the development of an effective vaccine.     

Campylobacter enteritis in The Gambia

In a three-month survey in The Gambia, campylobacters were isolated from 14·3% of 287 patients suffering from diarrhoea and from 4·2% of 383 patients and controls without diarrhoea. The equivalent figures for shigellas were 6·3% and 2·1%, and for salmonella 7·0% and 2·6% respectively. 53 (93%) of the 57 campylobacters were isolated from children less than five years old; none were isolated from indigenous adults (>15 years old). By using two selective media in parallel (Butzler's medium and Skirrow's medium), it was found that the number of isolations was increased by one third over that obtained with either medium alone.It is concluded that in The Gambia the transmission of campylobacters is of high intensity, with most infections occurring in young children, in whom these organisms are an important cause of morbidity and mortality.     

Malnutrition and gastroenteritis in The Gambia

There is a strong association between failure to thrive and diarrhoeal disease in young Gambian children.The high prevalence of diarrhoeal disease seen is not due to frequent attacks of “acute infantile diarrhoea” of viral origin. The picture of protracted diarrhoea is almost certainly due to colonization of the upper bowel and the high prevalence demonstrated to be at least partly due to the environment to which the children are exposed, particularly in terms of food and water hygiene.Until this cycle of upper bowel colonization and protracted diarrhoea is broken, a diet-based nutrition programme cannot be expected to function effectively.     

Surveillance report for active trachoma, 2006: National Trachoma Surveillance and Reporting Unit

The National Trachoma Surveillance and Reporting Unit (NTSRU) was established in November 2006 to improve the quality and consistency of data collection and reporting of active trachoma in Australia. Active trachoma data collected in 2006, prior to the commencement of the NTSRU, were reported by the Northern Territory, South Australia and Western Australia. In most regions, Aboriginal children aged 5-9 years were screened for signs of active trachoma, following the World Health Organization simplified trachoma grading system. In the Northern Territory the Healthy School Aged Kids program conducted school-based screening for active trachoma in 74 schools in five regions (n = 2,253). In South Australia Aboriginal school children presented for active trachoma screening when an eye team visited five Aboriginal Community Controlled Health Services (n = 275). In Western Australia population health units in collaboration with staff from population health care services, conducted school based screening for active trachoma in 53 schools in four regions (n = 1,719). Regional active trachoma prevalence for 2006 varied between the states and the Northern Territory with reported prevalences ranging from: Northern Territory = 2.5%-30%, South Australia = 0%-25%, and Western Australia = 18%-53%. Few data were reported on facial cleanliness or other aspects of the SAFE strategy, and no data were reported for trichiasis.     

Hib vaccine introduced in The Gambia

Acute respiratory infection (ARI) is the most common infectious cause of childhood death in Africa. Most deaths from ARI are caused by bacteria, including Haemophilus influenzae type b (Hib). Hib is also the most common bacterial cause of meningitis, except in those areas with outbreaks of meningococcal disease. Up to 40% of infants with meningitis die, and many of the survivors have permanent deafness and brain damage. Until recently, however, early diagnosis and treatment was the only defence against these infections. The newly developed Hib conjugate vaccines have been shown to be effective against Hib meningitis and pneumonia, and are now routinely used in infants in more than 25 countries around the world. A study of the efficacy of the vaccine in The Gambia's Western Region in 1993-95 showed that it was 95% effective in preventing meningitis and bloodstream infection, and 100% effective in preventing pneumonia. Hib vaccine was introduced this year in The Gambia as a routine immunization for children, to be given in the same injection as DTP at 2, 3, and 4 months of age. A 1-year study is underway to evaluate the impact of the vaccine upon disease. Trials are now underway for new pneumococcal and meningococcal vaccines which may be ready for wider use within 5-10 years.     

The relationship between prevalence of active trachoma, water availability and its use in a Tanzanian village

This study aimed to establish the relationship between the prevalence of active trachoma in children, water availability and household water use in a village in Tanzania. Nine hundred and fourteen children aged 1-9 years were examined for signs of trachoma. Data were collected on time taken to collect water, amount of water collected and other trachoma risk factors. In a sub-study, 99 randomly selected households were visited twice daily on two consecutive days to document patterns of water use. The prevalence of active trachoma in the children examined was 18.4% (95% CI 15.9-20.9). Active trachoma prevalence increased with increasing water collection time (OR 2.25; 95% CI 1.13-4.46) but was unrelated to the amount of water collected. In the sub-study, active trachoma prevalence was substantially lower in children from households where more water was used for personal hygiene (P for trend < or =0.01), independent of the total amount of water used. The allocation of water to hygiene was predicted by lower water collection time. The key element in the relationship between water availability and trachoma is the allocation of water within households. Collection time may influence both the quantity of water collected and its allocation within the household.     

Risk factors for kala-azar in Bangladesh

Since 1990, South Asia has experienced a resurgence of kala-azar (visceral leishmaniasis). To determine risk factors for kala-azar, we performed cross-sectional surveys over a 3-year period in a Bangladeshi community. By history, active case detection, and serologic screening, 155 of 2,356 residents had kala-azar with onset from 2000 to 2003. Risk was highest for persons 3-45 years of age, and no significant difference by sex was seen. In age-adjusted multivariable models, 3 factors were identified: proximity to a previous kala-azar patient (odds ratio [OR] 25.4, 95% confidence interval [CI] 15-44 within household; OR 3.2 95% CI 1.7-6.1 within 50 m), bed net use in summer (OR 0.7, 95% CI 0.53-0.93), and cattle per 1,000 m2 (OR 0.8, 95% CI 0.70-0.94]). No difference was seen by income, education, or occupation; land ownership or other assets; housing materials and condition; or keeping goats or chickens inside bedrooms. Our data confirm strong clustering and suggest that insecticide-treated nets could be effective in preventing kala-azar.     

Risk factors for atherosclerosis in twins

We performed multivariate genetic analyses of cardiovascular risk factors from two sets of data on US and Australian female twins. Similar models for body-mass index (BMI), serum low density (LDL) and high density (HDL) lipoproteins, including age as a covariate, were fitted successfully to both groups. These suggested that BMI, or genes responsible for a significant proportion of the variance of BMI, explained correlations between lipid subfractions, as well as those between blood pressure and lipid subfractions, especially HDL. © 1993 Wiley-Liss, Inc.     

Social factors and trachoma: a review of the literature

Although great advances have been made in the clinical understanding of trachoma, the disease remains endemic in many parts of the world. Economic, environmental, cultural and behavioral factors continue to play an important role in trachoma transmission and progression. The trachoma literature however, contains relatively few studies which rigorously assess the importance of social factors. A critical review of the trachoma literature implicates individual and community hygiene as important risk factors for disease. Specific risk behaviors remain to be identified and validated as independent predictors of infection in different settings. Collaboration between biomedical and social science professionals is needed to design and carry out further research.     

The household pattern of trachoma in Taiwan

A trachoma prevalence survey was conducted in 1960-61 in Taiwan prior to the introduction of a large-scale treatment campaign. During the survey information was collected by household and by individual. In the present report an attempt is made to depict the disease pattern in the household.     

Maternal mortality in rural Gambia: levels, causes and contributing factors

A demographic study carried out in a rural area of the Gambia between January 1993 and December 1998 recorded 74 deaths among women aged 15-49 years. Reported here is an estimation of maternal mortality among these 74 deaths based on a survey of reproductive age mortality, which identified 18 maternal deaths by verbal autopsy. Over the same period there were 4245 live births in the study area, giving a maternal mortality ratio of 424 per 100,000 live births. This maternal mortality estimate is substantially lower than estimates made in the 1980s, which ranged from 1005 to 2362 per 100,000 live births, in the same area. A total of 9 of the 18 deaths had a direct obstetric cause--haemorrhage (6 deaths), early pregnancy (2), and obstructed labour (1). Indirect causes of obstetric deaths were anaemia (4 deaths), hepatitis (1), and undetermined (4). Low standards of health care for obstetric referrals, failure to recognize the severity of the problem at the community level, delays in starting the decision-making process to seek health care, lack of transport, and substandard primary health care were identified more than once as probable or possible contributing factors to these maternal deaths.