Household crowding, social mixing patterns and respiratory symptoms in seven countries of the African meningitis belt.

OBJECTIVES: To describe the variation in household crowding and social mixing patterns in the African meningitis belt and to assess any association with self-reported recent respiratory symptoms. METHODS: In 2010, the African Meningococcal Carriage Consortium (MenAfriCar) conducted cross-sectional surveys in urban and rural areas of seven countries. The number of household members, rooms per household, attendance at social gatherings and meeting places were recorded. Associations with self-reported recent respiratory symptoms were analysed by univariate and multivariate regression models. RESULTS: The geometric mean people per room ranged from 1.9 to 2.8 between Ghana and Ethiopia respectively. Attendance at different types of social gatherings was variable by country, ranging from 0.5 to 1.5 per week. Those who attended 3 or more different types of social gatherings a week (frequent mixers) were more likely to be older, male (OR 1.27, p<0.001) and live in urban areas (OR 1.45, p<0.001). Frequent mixing and young age, but not increased household crowding, were associated with higher odds of self-reported respiratory symptoms (aOR 2.2, p<0.001 and OR 2.8, p<0.001 respectively). A limitation is that we did not measure school and workplace attendance. CONCLUSION: There are substantial variations in household crowding and social mixing patterns across the African meningitis belt. This study finds a clear association between age, increased social mixing and respiratory symptoms. It lays the foundation for designing and implementing more detailed studies of social contact patterns in this region

Pharyngeal carriage of Neisseria species in the African meningitis belt.

OBJECTIVES: Neisseria meningitidis, together with the non-pathogenic Neisseria species (NPNs), are members of the complex microbiota of the human pharynx. This paper investigates the influence of NPNs on the epidemiology of meningococcal infection. METHODS: Neisseria isolates were collected during 18 surveys conducted in six countries in the African meningitis belt between 2010 and 2012 and characterized at the rplF locus to determine species and at the variable region of the fetA antigen gene. Prevalence and risk factors for carriage were analyzed. RESULTS: A total of 4694 isolates of Neisseria were obtained from 46,034 pharyngeal swabs, a carriage prevalence of 10.2% (95% CI, 9.8-10.5). Five Neisseria species were identified, the most prevalent NPN being Neisseria lactamica. Six hundred and thirty-six combinations of rplF/fetA_VR alleles were identified, each defined as a Neisseria strain type. There was an inverse relationship between carriage of N. meningitidis and of NPNs by age group, gender and season, whereas carriage of both N. meningitidis and NPNs was negatively associated with a recent history of meningococcal vaccination. CONCLUSION: Variations in the prevalence of NPNs by time, place and genetic type may contribute to the particular epidemiology of meningococcal disease in the African meningitis belt

Risk factors for acquisition of meningococcal carriage in the African meningitis belt.

OBJECTIVE: To investigate potential risk factors for acquisition in seven countries of the meningitis belt. METHODS: Households were followed up every 2 weeks for 2 months, then monthly for a further 4 months. Pharyngeal swabs were collected from all available household members at each visit and questionnaires completed. Risks of acquisition over the whole study period and for each visit were analysed by a series of logistic regressions. RESULTS: Over the course of the study, acquisition was higher in: (i) 5-to 14-year olds, as compared with those 30 years or older (OR 3.6, 95% CI 1.4-9.9); (ii) smokers (OR 3.6, 95% CI 0.98-13); and (iii) those exposed to wood smoke at home (OR 2.6 95% CI 1.3-5.6). The risk of acquisition from one visit to the next was higher in those reporting a sore throat during the dry season (OR 3.7, 95% CI 2.0-6.7) and lower in those reporting antibiotic use (OR 0.17, 95% CI 0.03-0.56). CONCLUSIONS: Acquisition of meningococcal carriage peaked in school age children. Recent symptoms of sore throat during the dry season, but not during the rainy season, were associated with a higher risk of acquisition. Upper respiratory tract infections may be an important driver of epidemics in the meningitis belt

Pharyngeal carriage of Neisseria species in the African meningitis belt.

OBJECTIVES: Neisseria meningitidis, together with the non-pathogenic Neisseria species (NPNs), are members of the complex microbiota of the human pharynx. This paper investigates the influence of NPNs on the epidemiology of meningococcal infection. METHODS: Neisseria isolates were collected during 18 surveys conducted in six countries in the African meningitis belt between 2010 and 2012 and characterized at the rplF locus to determine species and at the variable region of the fetA antigen gene. Prevalence and risk factors for carriage were analyzed. RESULTS: A total of 4694 isolates of Neisseria were obtained from 46,034 pharyngeal swabs, a carriage prevalence of 10.2% (95% CI, 9.8-10.5). Five Neisseria species were identified, the most prevalent NPN being Neisseria lactamica. Six hundred and thirty-six combinations of rplF/fetA_VR alleles were identified, each defined as a Neisseria strain type. There was an inverse relationship between carriage of N. meningitidis and of NPNs by age group, gender and season, whereas carriage of both N. meningitidis and NPNs was negatively associated with a recent history of meningococcal vaccination. CONCLUSION: Variations in the prevalence of NPNs by time, place and genetic type may contribute to the particular epidemiology of meningococcal disease in the African meningitis belt.MenAfriCar was funded by the Wellcome Trust (086546/Z/08/Z) and the Bill and Melinda Gates Foundation (51251). Kanny Diallo holds a Wellcome Trust Training Fellowship in Public Health and Tropical Medicine.This is the final version of the article. It first appeared from Elsevier via https://doi.org/10.1016/j.jinf.2016.03.01

Correction: A Seroepidemiological Study of Serogroup A Meningococcal Infection in the African Meningitis Belt.

[This corrects the article DOI: 10.1371/journal.pone.0147928.]

Neighborhood environment and quality of life among community-living older adults in Nigeria: The moderating effect of physical activity.

Understanding how neighborhood environments are related to older adults quality of life (QoL) and physical activity (PA) is important for public health actions on healthy ageing in sub-Saharan Africa. We examined associations of perceived neighborhood environment attributes with QoL among older adults in Nigeria and investigated the moderating effects of PA on these associations. We conducted a cross-sectional study of 353 older adults (mean age&nbsp;=&nbsp;68.9&nbsp;±&nbsp;9.1&nbsp;years) selected from 5 high- and low-income communities in Maiduguri, Nigeria. QoL, attributes of the neighborhood environments and PA were self-reported using validated questionnaires. Multi-level models were used to examine the direct associations between neighborhood environment attributes and each of the four domains of QoL (physical health, psychological health, social relationships, and environmental health), as well as the moderating effects of leisure-time and total PA. Seven of nine neighborhood environment features were positively associated with multiple domains of QoL. Residential density, land-use diversity, land-use mix-access, walking infrastructure, traffic safety and overall walkability were positively related to both or either physical health and environmental health QoL among those who are physically active. In contrast, walking infrastructure, traffic safety, and overall walkability were negatively related to psychological health QoL among those not physically active. Our findings suggest being physically active moderates the association of neighborhood environments with QoL among Nigerian older adults. We suggest that designing age-friendly communities and simultaneously promoting PA may be needed to improve QoL and help prepare the Nigerian society for the predicted increase in the older adult population

Neighborhood environment and quality of life among community-living older adults in Nigeria: The moderating effect of physical activity

Understanding how neighborhood environments are related to older adults’ quality of life (QoL) and physical activity (PA) is important for public health actions on healthy ageing in sub-Saharan Africa. We examined associations of perceived neighborhood environment attributes with QoL among older adults in Nigeria and investigated the moderating effects of PA on these associations. We conducted a cross-sectional study of 353 older adults (mean age = 68.9 ± 9.1 years) selected from 5 high- and low-income communities in Maiduguri, Nigeria. QoL, attributes of the neighborhood environments and PA were self-reported using validated questionnaires. Multi-level models were used to examine the direct associations between neighborhood environment attributes and each of the four domains of QoL (physical health, psychological health, social relationships, and environmental health), as well as the moderating effects of leisure-time and total PA. Seven of nine neighborhood environment features were positively associated with multiple domains of QoL. Residential density, land-use diversity, land-use mix-access, walking infrastructure, traffic safety and ‘overall walkability’ were positively related to both or either physical health and environmental health QoL among those who are physically active. In contrast, walking infrastructure, traffic safety, and ‘overall walkability’ were negatively related to psychological health QoL among those not physically active. Our findings suggest being physically active moderates the association of neighborhood environments with QoL among Nigerian older adults. We suggest that designing age-friendly communities and simultaneously promoting PA may be needed to improve QoL and help prepare the Nigerian society for the predicted increase in the older adult population

Associations of Neighborhood Walkability with Sedentary Time in Nigerian Older Adults

Previous studies have investigated the potential role of neighborhood walkability in reducing sedentary behavior. However, the majority of this research has been conducted in adults and Western developed countries. The purpose of the present study was to examine associations of neighborhood environmental attributes with sedentary time among older adults in Nigeria. Data from 353 randomly-selected community-dwelling older adults (60 years and above) in Maiduguri, Nigeria were analyzed. Perceived attributes of neighborhood environments and self-reported sedentary time were assessed using Nigerian-validated and reliable measures. Outcomes were weekly minutes of total sedentary time, minutes of sitting on a typical weekday, and minutes of sitting on a typical weekend day. In multivariate regression analyses, higher walkability index, proximity to destinations, access to services, traffic safety, and safety from crime were associated with less total sedentary time and sedentary time on both a weekday and a weekend day. Moderation analysis showed that only in men was higher walking infrastructure and safety found to be associated with less sedentary time, and higher street connectivity was associated with more sedentary time. The findings suggest that improving neighborhood walkability may be a mechanism for reducing sedentary time among older adults in Nigeria