Role of schools in the transmission of measles in rural Senegal: implications for measles control in developing countries.
Patterns of measles transmission at school and at home were studied in 1995 in a rural area of Senegal with a high level of vaccination coverage. Among 209 case children with a median age of 8 years, there were no deaths, although the case fatality ratio has previously been 6-7% in this area. Forty percent of the case children had been vaccinated against measles; the proportion of vaccinated children was higher among secondary cases (47%) than among index cases (33%) (prevalence ratio = 1.36, 95% confidence interval (CI) 1.04-1.76). Vaccinated index cases may have been less infectious than unvaccinated index cases, since they produced fewer clinical cases among exposed children (relative risk = 0.55, 95% CI 0.29-1.04). The secondary attack rate was lower in the schools than in the homes (relative risk = 0.31, 95% CI 0.20-0.49). The school outbreaks were protracted, with 4-5 generations of cases being seen in the two larger schools. Vaccine efficacy was found to be 57% (95% CI -23 to 85) in the schools and 74% (95% CI 62-82) in the residential compounds. Measles infection resulted in a mean of 3.8 days of absenteeism per case, though this did not appear to have an impact on the children's grades. Among the index cases, 56% of children were probably infected by neighbors in the community, and 7% were probably infected at health centers, 13% outside the community, and 24% in one of the three schools which had outbreaks during the epidemic. However, most of the school-related cases occurred at the beginning and therefore contributed to the general propagation of the epidemic. To prevent school outbreaks, it may be necessary to require vaccination prior to school entry and to revaccinate children in individual schools upon detection of cases of measles. Multidose measles vaccination schedules will be necessary to control measles in developing countries. (+info)
nvited commentary: vaccine failure or failure to vaccinate?
The present state and future prospects of occupational health in Bangladesh.
Bangladesh is a relatively young and developing country. At the present time, like in most developing countries, a clear demarcation between occupational health care and general medical care is difficult to be recognized in Bangladesh. Occupational health is a fairly new field, as the country is undergoing industrialization and occupational health activities are operated by several ministries, such as Labour, Health, Industry and Transport. Legal foundations of the occupational health-care system based on British India and Pakistani era, were adopted and amended by the Government of Bangladesh after the liberation of the country in 1971. Most of the Labour laws have been rectified by the Government of Bangladesh according to the ILO Conventions. Reconsideration of the occupational health service system avoiding duplication for the 'occupational health' component in several ministries might be helpful to achieve the successful provision of an occupational health service in the developing Bangladesh. (+info)
Epidemiology and prevention of group A streptococcal infections: acute respiratory tract infections, skin infections, and their sequelae at the close of the twentieth century.
Infections of the upper respiratory tract and skin due to group A Streptococcus are common, and the organism is highly transmissible. In industrialized countries and to some extent in developing countries, control efforts continue to emphasize that group A streptococcal pharyngitis should be properly diagnosed and appropriately treated. In developing countries and in indigenous populations where the burden of group A streptococcal diseases appears greatest, the epidemiology is less completely defined and may differ from that in industrialized countries. There is a need for accurately collected epidemiological data from developing countries, which may also further clarify the pathogenesis of group A streptococcal infections and their sequelae. While proper treatment of group A streptococcal pharyngitis continues to be essential in all populations, it may be appropriate in developing countries to consider additional strategies to reduce rates of pyoderma. (+info)
Antibiotic strategies for developing countries: experience with acute respiratory tract infections in Pakistan.
The Pakistan program for control of acute respiratory tract infections (ARIs) adopted the standard ARI-case-management strategy of the World Health Organization and recommended co-trimoxazole for the management of nonsevere pneumonia. Reports in that country of high in vitro antimicrobial resistance of Streptococcus pneumoniae and Haemophilus influenzae to co-trimoxazole prompted the program to reevaluate its treatment policy. Two community-based studies during 1991-1993 showed in vivo efficacy of co-trimoxazole in 92% and 91% of children with nonsevere pneumonia. A third double-blind trial showed co-trimoxazole and oral amoxicillin to be equally effective in vivo in cases of nonsevere pneumonia, despite high in vitro resistance. Country-wide surveillance from 1991 to 1994 revealed 78.3%-79.9% in vitro resistance to co-trimoxazole among S. pneumoniae isolates and 59.5%-61.0% among H. influenzae isolates. Co-trimoxazole is still recommended by the Pakistan ARI control program. The fact that amoxicillin is three times more expensive and must be administered more frequently is a big impediment to recommending it as a first-line drug for nonsevere pneumonia. (+info)
Burden of infection on growth failure.
The high prevalence of infections among children living in poor areas of developing countries impairs linear growth in these populations. Acute, invasive infections, which provoke a systemic response (e.g., dysentery and pneumonia), and chronic infections, which affect the host over a sustained period (e.g., gut helminth infections), have a substantial effect on linear growth. Such infections can diminish linear growth by affecting nutritional status. This occurs because infections may decrease food intake, impair nutrient absorption, cause direct nutrient losses, increase metabolic requirements or catabolic losses of nutrients and, possibly, impair transport of nutrients to target tissues. In addition, induction of the acute phase response and production of proinflammatory cytokines may directly affect the process of bone remodeling that is required for long bone growth. Infection of cells directly involved in bone remodeling (osteoclasts or osteoblasts) by specific viruses may also directly affect linear growth. Many interventions are possible to diminish the effect of infection on growth. Prevention of disease through sanitation, vector control, promotion of breast-feeding and vaccination is crucial. Appropriate treatment of infections (e.g., antibiotics for pneumonia) as well as supportive nutritional therapy (again including breast-feeding) during and after recovery, is also important. Targeted therapeutic interventions to decrease the prevalence of gut helminth infections may also be appropriate in areas in which such infections are widespread. Such interventions are of public health benefit not only because they reduce the incidence or severity of infections, but also because they decrease the long-term detrimental effect of malnutrition on populations. (+info)
Role of intergenerational effects on linear growth.
Current knowledge on the role of intergenerational effects on linear growth is reviewed on the basis of a literature search and recent findings from an ongoing study in Guatemala. Fourteen studies were identified, most of which examined the intergenerational relationships in birth weight. Overall, for every 100 g increase in maternal birth weight, her child's birth weight increased by 10-20 g. The study samples were primarily from developed countries, and birth weight data were extracted from hospital records and/or birth registries. Among the few studies that examined associations between the adult heights of parents and their offspring, correlation coefficients of 0.42-0.5 were reported. None of the studies examined intergenerational relationships in birth length or linear growth patterns during early childhood, preadolescence and/or adolescence. Prospectively collected data from long-term studies being carried out in rural Guatemala provide the first evidence of intergenerational relationships in birth size in a developing country setting. Data were available for 215 mother-child pairs. Maternal birth size was a significant predictor (P < 0.05) of child's birth size after adjusting for gestational age and sex of the child and other potential confounders. Child's birth weight increased by 29 g/100 g increase in maternal birth weight which is nearly twice that reported in developed countries. Similarly, child's birth length increased by 0.2 cm for every 1 cm increase in mother's birth length. The effect of maternal birth weight remained significant even after adjusting for maternal adult size. More evidence from developing countries will help explain the underlying mechanisms and identify appropriate interventions to prevent growth retardation. (+info)
Risk of Helicobacter pylori infection among long-term residents in developing countries.
The seroprevalence and incidence of Helicobacter pylori infection were determined among 312 North American missionaries who were serving in developing countries between 1967 and 1984. The majority (81%) resided in sub-Saharan Africa. When initially evaluated, the missionaries had a mean age of 40 years, 65% were female, and all were of white race/ethnicity. An ELISA showed that the initial prevalence of IgG antibody to H. pylori was 17%. After a mean of 7.4 years of service (1917 person-years of exposure), 37 (14%) of 259 initially seronegative subjects seroconverted to anti-H. pylori, giving an annual incidence of 1.9%. These data indicate a relatively higher risk of H. pylori infection among missionaries compared with an annual incidence of seroconversion of 0.3-1.0% in industrialized nations. Long-term residents in developing countries should be evaluated for H. pylori infection when gastrointestinal symptoms develop. (+info)