Urban Health Bulletin, January 2010 (11 studies)
This January 2010 issue of the Urban Health Bulletin contains citations and abstracts to 11 recently published health studies on urban health issues in Brazil, Ethiopia, Kenya, Mexico, Pakistan and Peru.
1 – Int J Epidemiol. 2010 Jan 20.
Evaluation of the optimal recall period for disease symptoms in home-based morbidity surveillance in rural and urban Kenya.
Feikin DR, Audi A, Olack B, Bigogo GM, Polyak C, Burke H, Williamson J, Breiman RF.
International Emerging Infections Program, Kenya, and Centers for Disease Control and Prevention, Nairobi and Kisumu, Kenya, Centre for Global Health Research, Kenya Medical Research Institute, Kisumu, Kenya and Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
BACKGROUND: In African settings with poor access to health care, surveillance and surveys of disease burden are often done through home visits. The optimal recall period to capture data on symptoms and health utilization is unknown.
METHODS: We collected illness data among 53 000 people during fortnightly home visits in rural and urban Kenya. Rates of cough, fever and diarrhoea in the past 2 weeks and health-seeking behaviour were recorded. Incidence rates were modelled using Poisson regression for data collected from 1 July 2006 to 30 June 2007.
RESULTS: Incidence rates were higher in days 0-6 before the home visit than in days 7-13 before the home visit for all three symptoms, for the rural and urban sites, for children and adults, for self- and proxy-reported symptoms and for severe and non-severe illness in children. Recall decay was steeper in the rural than the urban sites, and for proxy- than self-reported symptoms. The daily prevalence of symptoms fell 3 days before the home visit for children and >4 days for persons >/=5 years of age. Recall of previously documented clinic visits, and prescriptions of antimalarials and antibiotics also declined by approximately 7, 15 and 23% per week, respectively, in children aged <5 years, and 6, 20 and 16%, respectively, in older persons (P < 0.0001 for each decline).
CONCLUSIONS: A 2-week recall period underestimates true disease rates and health-care utilization. Shorter recall periods of 3 days in children and 4 days in adults would likely yield more accurate data.
2 – BMC Public Health. 2009 Dec 15;9:465.
Overweight and obesity in urban Africa: A problem of the rich or the poor?
Ziraba AK, Fotso JC, Ochako R. African Population and Health Research Center (APHRC), PO Box 10787, 00100, Nairobi, Kenya. firstname.lastname@example.org
BACKGROUND: Obesity is a well recognized risk factor for various chronic diseases such as cardiovascular diseases, hypertension, and type 2 diabetes mellitus. The aim of this study was to shed light on the patterns of overweight and obesity in sub-Saharan Africa, with special interest in differences between the urban poor and the urban non-poor. The specific goals were to describe trends in overweight and obesity among urban women; and examine how these trends vary by education and household wealth.
METHODS: The paper used Demographic and Health Surveys data from seven African countries where two surveys had been carried out with an interval of at least 10 years between them. Among the countries studied, the earliest survey took place in 1992 and the latest in 2005. The dependent variable was body mass index coded as: Not overweight/obese; Overweight; Obese. The key covariates were time lapse between the two surveys; woman’s education; and household wealth. Control variables included working status, age, marital status, parity, and country. Multivariate ordered logistic regression in the context of the partial proportional odds model was used.
RESULTS: Descriptive results showed that the prevalence of urban overweight/obesity increased by nearly 35% during the period covered. The increase was higher among the poorest (+50%) than among the richest (+7%). Importantly, there was an increase of 45-50% among the non-educated and primary-educated women, compared to a drop of 10% among women with secondary education or higher. In the multivariate analysis, the odds ratio of the variable time lapse was 1.05 (p < 0.01), indicating that the prevalence of overweight/obesity increased by about 5% per year on average in the countries in the study. While the rate of change in urban overweight/obesity did not significantly differ between the poor and the rich, it was substantially higher among the non-educated women than among their educated counterparts.
CONCLUSION: Overweight and obesity are on the rise in Africa and might take epidemic proportions in the near future. Like several other public health challenges, overweight and obesity should be tackled and prevented early as envisioned in the WHO Global strategy on diet, physical activity and health.
3 – J Vector Borne Dis. 2009 Dec;46(4):273-9.
Entomological assessment of the potential for malaria transmission in Kibera slum of Nairobi, Kenya.
Kasili S, Odemba N, Ngere FG, Kamanza JB, Muema AM, Kutima HL. Centre for Biotechnology Research and Development, Kenya Medical Research Institute, Nairobi, Kenya. email@example.com
BACKGROUND & OBJECTIVES: Malaria in urban and highland areas is emerging as a significant public health threat in Kenya which has seen a dramatic increase in malaria transmission in low risk highland areas. The objectives of the study were to find and incriminate potential vectors of malaria in Kibera, Nairobi.
METHODS: One hundred and twenty houses within Lindi area of the southern central section of Kibera slum in Nairobi were chosen randomly and global positioning system (GPS) mapped. Day resting indoor mosquitoes were collected from January 2001 to December 2003. Larvae were collected between 2002 and 2004 and reared in the insectary to adults.
RESULTS: A total of 176,993 mosquitoes were collected. Out of this, 176,910 were Culex fatigans and 83 were Anopheles gambiae s.l. Mosquito population peaked during the long rains in April to May and the short rains in November and December. Blood meal analysis of An. gambiae s.l. female mosquitoes revealed 0.97 human blood index. No mosquito was found positive for Plasmodium falciparum sporozoites. Anopheles gambiae s.l. mosquitoes were found breeding in polluted water and 95% of the larvae were identified as An. arabiensis.
INTERPRETATION & CONCLUSION: Anopheles gambiae s.l., malaria vector is present in Nairobi and it breeds in polluted water. Anopheles arabiensis is predominantly preferring humans as blood meal source, thus, showing ecological flexibility within the species.
4 – Rev Saude Publica. 2009 Dec;43(6):1006-14.
Surveillance of mother-to-child HIV transmission: socioeconomic and health care coverage indicators.
Barcellos C, Acosta LM, Lisboa E, Bastos FI. Laboratório de Informações em Saúde, Instituto de Comunicação e Informação Científica e Tecnológica em Saúde, Fundação Oswaldo Cruz, Avenida Brasil 4365-Manguinhos, Rio de Janeiro, RJ, Brazil. firstname.lastname@example.org
OBJECTIVE: To identify clustering areas of infants exposed to HIV during pregnancy and their association with indicators of primary care coverage and socioeconomic condition.
METHODS: Ecological study where the unit of analysis was primary care coverage areas in the city of Porto Alegre, Southern Brazil, in 2003. Geographical Information System and spatial analysis tools were used to describe indicators of primary care coverage areas and socioeconomic condition, and estimate the prevalence of liveborn infants exposed to HIV during pregnancy and delivery. Data was obtained from Brazilian national databases. The association between different indicators was assessed using Spearman’s nonparametric test.
RESULTS: There was found an association between HIV infection and high birth rates (r=0.22, p<0.01) and lack of prenatal care (r=0.15, p<0.05). The highest HIV infection rates were seen in areas with poor socioeconomic conditions and difficult access to health services (r=0.28, p<0.01). The association found between higher rate of prenatal care among HIV-infected women and adequate immunization coverage (r=0.35, p<0.01) indicates that early detection of HIV infection is effective in those areas with better primary care services.
CONCLUSIONS: Urban poverty is a strong determinant of mother-to-child HIV transmission but this trend can be fought with health surveillance at the primary care level.
5 – Inj Prev. 2009 Dec;15(6):390-6.
Falls, poisonings, burns, and road traffic injuries in urban Peruvian children and adolescents: a community based study.
Donroe J, Gilman RH, Brugge D, Mwamburi M, Moore DA. Asociación Benéfica PRISMA, San Miguel, Lima, Perú. email@example.com
OBJECTIVES: To identify individual and household characteristics associated with serious falls, poisonings, burns and road traffic injuries (RTIs) for children in Lima, Peru.
METHODS: 5061 households consisting of 10,210 children were included in this community based, cross-sectional study in San Juan de Miraflores (SJM), a low income, urban district of Lima, Peru. Households were eligible if there was a consenting adult and at least one resident child aged < or =18 years. A door to door survey was conducted in SJM, collecting childhood injury, demographic, and socioeconomic data. Analysis was done at the individual and household level for injuries severe enough to have required medical consultation.
RESULTS: The greatest burden of injury was from falls and RTIs. For individuals, male gender and age were the most important predictors of injuries. Households in which multiple injuries were reported were more likely to be poor (odds ratio (OR) 1.66, 95% CI 1.24 to 2.22) and overcrowded (OR 1.88, 95% CI 1.20 to 2.94). The occurrence of serious falls, poisonings, burns, and pedestrian RTIs significantly increased the likelihood of a second serious injury in the home (adjusted ORs ranged between 1.88 and 2.99).
CONCLUSION: All children from households in which an unintentional injury has occurred appear to have an increased likelihood of future injury; such high risk households may be readily identifiable in the clinical setting. Interventions in this environment designed to prevent subsequent injuries merit further investigation.
6 – Am J Hum Biol. 2010 Jan-Feb;22(1):60-8.
Children’s work, earnings, and nutrition in urban Mexican shantytowns.
Brewis A, Lee S. Arizona State University, Tempe, 85287-2402, USA. Alex.Brewis@asu.edu
For many children living in conditions of urban poverty, earning money can provide additional resources to them and their families, and this raises interesting questions about the potential biological consequences (costs and benefits) of children’s work in ‘modern’ settings. This study uses time allocation, ethnographic, dietary, and anthropometric data collected with 96 urban Mexican shantytown children (aged 8-12 years) and their older and younger siblings (aged 1-18 years) to test hypotheses related to the effects of children’s cash earning and cash contributions to their households for their own and their sibs’ nutritional status. Regression models show that children’s contributions to household income and the time they allocate to working outside the home makes no difference to their own or their younger siblings’ nutritional status assessed anthropometrically. Dietary quality, based on food recalls, is worse in working than non-working children, even taking household income into account. Children’s allocation of time to work and their cash contributions to the household do however significantly improve the weight of their older siblings, especially sisters. This suggests children’s work in urban ecologies might have different constraints and opportunities for their own and siblings’ growth and nutrition than typically observed in subsistence settings.
7 Microbes Infect. 2010 Jan 20.
The dengue vector Aedes aegypti: What comes next.
Jansen CC, Beebe NW. CSIRO Entomology, Long Pocket Laboratories, Indooroopilly, QLD, 4068, Australia.
Aedes aegypti is the urban vector of dengue viruses worldwide. While climate influences the geographical distribution of this mosquito species, other factors also determine the suitability of the physical environment for this mosquito. Importantly, the close association of Ae. aegypti with humans and the domestic environment allows this species to persist in regions that may otherwise be unsuitable based on climatic factors alone. We highlight the need to incorporate the impact of the urban environment in attempts to model the potential distribution of Ae. aegypti and briefly discuss the potential for future technology to aid management and control of this widespread vector species.
8 – BMC Public Health. 2010 Jan 19;10(1):21.
Prevalence and risk factors for soil-transmitted helminth infection in mothers and their infants in Butajira, Ethiopia: a population based study.
Belyhun Y, Medhin G, Amberbir A, Erko B, Hanlon C, Alem A, Venn A, Britton J, Davey G.
Background – Soil-transmitted helminths (STHs) are widespread in underdeveloped countries. In Ethiopia, the prevalence and distribution of helminth infection varies by place and with age. We therefore investigated the
prevalence of and risk factors for STH infection in mothers and their one year-old children living in Butajira town and surrounding rural areas in southern Ethiopia.
Methods – In 2005-2006, 1065 pregnant women were recruited in their third trimester of pregnancy. In 2006-2007, when children reached their first birthdays, data on the infants and their mothers were collected, including stool samples for qualitative STH analysis. Questionnaire data on various demographic, housing and lifestyle variables were available. Logistic regression analysis was employed to determine the independent risk factors for STH infection in the mothers and children.
Results – 908 mothers and 905 infants provided complete data for analysis. Prevalence of any STH infection was 43.5% (95% confidence interval (CI) 40.2-46.8%) in mothers and 4.9% (95%CI 3.6-6.5%) in children. In the fully adjusted regression model, infrequent use of soap by the mother was associated with increased risk (odds ratio (OR) 1.40, 95% CI 1.04-1.88, and 1.66, 95% CI 0.92-2.99, for use at least once a week and less frequent than once a week respectively, relative to daily use; p for trend=0.018), and urban place of residence (OR 0.45, 95% CI 0.28-0.73, p=0.001) was associated with reduced risk of maternal STH infection. The only factor associated with STH infection in infants was household source of water, with the greatest risk in those using piped water inside the compound (OR 0.09, 95% CI 0.02-0.38 for river water, 0.20, 95% CI 0.56-0.69 for either well or stream water and 0.21, 95% CI 0.09-0.51 for piped water outside compared with piped water inside the compound, overall p=0.002)
Conclusion In this rural Ethiopian community with a relatively high prevalence of STH infection, we found a reduced risk of infection in relation to maternal hygiene and urban living. Daily use of soap and a safe supply of water are likely to reduce the risk of STH infection.
9 – Issues Ment Health Nurs. 2010 Feb; 31(2):82-8.
Development of an economic skill building intervention to promote women’s safety and child development in Karachi, Pakistan.
Hirani SS, Karmaliani R, McFarlane J, Asad N, Madhani F, Shehzad S, Ali NA. The Aga Khan University, School of Nursing, P. O. Box 3500, Stadium Road, Karachi 74800 Pakistan. firstname.lastname@example.org
Violence against women is a global epidemic phenomenon that can result in major mental health problems. Not only are women affected but also the health and well-being of their children are in jeopardy. To prevent violence and promote women’s safety, several strategies have been tested in various cultural contexts. This article describes the process of developing and validating an economic skill building intervention for women of an urban slum area of Karachi, Pakistan. The purpose of the intervention is to increase women’s economic independence, promote women’s safety, and improve the behavioral functioning of their children.
10 – J R Soc Interface. 2010 Jan 8.
Rational spatio-temporal strategies for controlling a Chagas disease vector in urban environments.
Levy MZ, Malaga Chavez FS, Cornejo Del Carpio JG, Vilhena DA, McKenzie FE, Plotkin JB.
Department of Biology, University of Pennsylvania, , 219 Carolyn Lynch Laboratories, Philadelphia, PA 19104, USA.
The rational design of interventions is critical to controlling communicable diseases, especially in urban environments. In the case of the Chagas disease vector Triatoma infestans, successful control is stymied by the return of the insect after the effectiveness of the insecticide wanes. Here, we adapt a genetic algorithm, originally developed for the travelling salesman problem, to improve the spatio-temporal design of insecticide campaigns against T. infestans, in a complex urban environment. We find a strategy that reduces the expected instances of vector return 34-fold compared with the current strategy of sequential insecticide application to spatially contiguous communities. The relative success of alternative control strategies depends upon the duration of the effectiveness of the insecticide, and it shows chaotic fluctuations in response to unforeseen delays in a control campaign. We use simplified models to analyse the outcomes of qualitatively different spatio-temporal strategies. Our results provide a detailed procedure to improve control efforts for an urban Chagas disease vector, as well as general guidelines for improving the design of interventions against other disease agents in complex environments.
11 – Acta Paediatr. 2010 Jan 5.
Breastfeeding perceptions in communities in Mangochi district in Malawi.
Kamudoni PR, Maleta K, Shi Z, de Paoli MM, Holmboe-Ottesen G. Institute of General Practice and Community Medicine, University of Oslo, Oslo, Norway.
Aim: To investigate mothers’ perceptions of breastfeeding and influences from their social network.
Methods: A cross-sectional survey was carried out in Mangochi district, Malawi where questionnaire data from 157 rural and 192 semi-urban mother-infant pairs were obtained.
Results: The proportion of mothers who thought that exclusive breastfeeding should last for 6 months and those who reported to have actually exclusively breastfed were 40.1% and 7.5% respectively. Of those who reported practising exclusive breastfeeding for 6 months, 77.5% stated that exclusive breastfeeding should last for 6 months. This opinion was independently associated with giving birth in a Baby-Friendly facility, OR = 5.22; 95% CI (1.92-14.16). Among the mothers who thought that exclusive breastfeeding should last for less than 6 months, 43.9% reported having been influenced in their opinion by health workers. Infant crying was the most common (62.4%) reason for stopping exclusive breastfeeding.
Conclusion: The findings illustrate the positive impact health workers can have, as well as the need to raise awareness of the benefits of exclusive breastfeeding among both health workers and mothers. Furthermore, continued counselling of mothers on how to deal with stressful infant behaviour such as crying may assist to prolong exclusive breastfeeding.