Cancer incidence in an urban community: an historical cohort study

This historical cohort study tested the hypothesis that residents of an industrialized urban community were at higher risk of cancer than residents of a comparable, but non-industrialized, community. The exposed (C1) and the unexposed (C2) cohorts resided in their respective neighbourhoods between 1952 and 1956. All incident cancers were identified through linkage with the Ontario Cancer Registry for 1964-1982. Cancer incidence rates in the two cohorts were 7.0 and 7.3 per 1,000 person-years, respectively. Relative risk estimates for all cancers, lung cancer and cancers associated with environmental exposure, were not significantly different from 1.0. Only colorectal cancers were significantly more frequent in the C1 than the C2 cohort, and these only in one sub-analysis. Overall, we conclude that if there was increased risk of cancer related to environmental pollution in the industrially exposed community, it was less than a two-fold increase.     

Coronary heart disease risk factors in sub-Saharan Africa: studies in Tanzanian adolescents.

STUDY OBJECTIVE--To assess the level of cardiovascular risk factors in young people in sub-Saharan Africa living in rural and urban settings. DESIGN--Cross sectional survey of the population aged 15 to 19 years. SETTING--Eight rural Tanzanian villages in three regions, and two districts in Dar es Salaam. PARTICIPANTS--664 males and 803 females in rural villages and 85 males and 121 females in the city. Response rates for total population were 74% to 94% in the rural areas and 60% in the city. MEASUREMENTS AND RESULTS--Measurements included blood pressure, body mass index, serum lipids, and blood glucose concentrations (fasting and two hours after 75 g glucose). Blood pressure was slightly but significantly higher in young women than in young men (115/67 mmHg versus 113/65 mmHg) and increased significantly with age. Only 0.4% subjects had blood pressure greater than 140 and/or 90 mmHg. There were no urban-rural differences. Body mass index was higher in females (mean (SD) 20.3 (2.8) kg/m2) than males (18.5 (2.1)). Overweight was found in only 0.6% at age 15 years but 5.4% at age 19 years. Serum cholesterol concentrations were low at 3.5 mmol/l in males and 3.7 mmol/l in females. Only 7% had values above 5.2 mmol/l. The highest concentrations were found in the city and in Kilimanjaro, the most prosperous rural region. Serum triglycerides were 1.0 (0.5) mmol/l in males and 1.1 (0.5) mmol/l in females, and were highest in the city dwellers. Diabetes was rare (0.28% males, 0.12% females) but impaired glucose tolerance was present in 4.7% and 4.1% respectively. Drinking alcohol was equally prevalent in males and females, reaching 30% at age 19 years. Only 0.4% of females smoked compared with 7.3% of males. Smoking was commoner in rural areas that in the city. CONCLUSIONS--Several risk factors for cardiovascular disease were found in Tanzanian adolescents, but levels were much lower than in studies reported from developed nations. The challenge is to maintain these low levels as the population becomes more urbanised and more affluent.     

Transmission of tuberculosis in a high incidence urban community in South Africa

BACKGROUND: The objective of this study was to identify risk factors for ongoing community transmission of tuberculosis (TB) in two densely populated urban communities with a high incidence rate of TB in Cape Town, South Africa. METHODS: Between 1993 and 1998 DNA fingerprints of mycobacterial isolates from TB patients were determined by restriction fragment length polymorphism (RFLP). Cases whose isolates shared identical fingerprint patterns were considered to belong to the same cluster and to be attributable to ongoing community transmission. RESULTS: The average annual notification rate of new smear positive TB was 238/100000. In all, 1023/1526 reported patients were culture positive, and RFLP was available for 768 (75%) of the isolates from these patients. Since some patients experienced more than one infection during the study period, 797 cases were included in the analysis. Of the cases, 575/797 (72%) were clustered. Smear-positive cases and those who were retreated after default were more likely to be clustered than smear-negative and new cases, respectively. Patients from Uitsig were more often part of large clusters than were patients from Ravensmead. Age, sex, year of diagnosis, and outcome of disease were not risk factors for clustering, nor for being the first case in a cluster, although various analytical approaches were used. CONCLUSIONS: The incidence and proportion of cases that are clustered in this area are higher than reported elsewhere. An overwhelming majority of TB cases in this area is attributed to ongoing community transmission, and only very few to reactivation. This may explain the lack of demographic risk factors for clustering.     

Motherhood in sub-Saharan Africa: the social consequences of infertility in an urban population in northern Tanzania

This paper examines the personal and social ramifications of infertility in an African urban population with low fertility. The study was conducted in Moshi, Tanzania, a multi-ethnic community with relatively high levels of education and a well developed health services infrastructure. The major question to be addressed was whether in a low fertility urban population, both primary and secondary infertility bring about serious personal ramifications for women similar to those in rural areas. The methodology included a survey of 2,019 women and in-depth interviews with 25 fertile and 25 infertile women. Of the 1,549 sexually active women in a regular union, 2.7% had never had a child in spite of trying to conceive for at least two years. Of the 1,352 women who had previously had a child, an additional 6.1% were subsequently infertile. The most important finding from the qualitative analysis concerns the major difference between childlessness and subsequent infertility (or primary and secondary infertility) in terms of implications for the effected women. These findings underline the importance of bearing a child in sub-Saharan African populations.     

Nutrition and HIV/AIDS in sub-Saharan Africa: an overview

HIV/AIDS is most prevalent in Sub-Saharan Africa where, exacerbated by the presence of other common conditions such as malnutrition and opportunistic infections, it is wreaking devastation on families, communities, and nations. Just as epidemics vary by country, so do national responses to this complex emergency. This is illustrated by the cases of Botswana, South Africa, and Uganda. Nutritional and micronutrient deficiencies play an important additive role in immune degradation and impaired development in children. Careful implementation of antiretroviral drugs, complemented by simultaneous efforts to ensure proper nutrition among HIV-infected children and adults are essential components of an effective response to the HIV/AIDS pandemic in Africa and elsewhere.     

Behavioral risk factors in an Amish community

A representative sample of 400 Amish adults residing in Holmes County, Ohio, was interviewed about certain health risk characteristics and behaviors, using the Behavioral Risk Factor Survey (BRFS). For purposes of comparison, a representative sample of 773 non-Amish adults responded to the same survey by telephone interviews. In general, the Amish report lower rates of alcohol and tobacco consumption than their non-Amish counterparts. The Amish are less likely to salt their food and are more likely to take vitamin supplements, but do not differ from non-Amish in the consumption of "health foods." Amish men and women are less likely to be trying to lose weight than their non-Amish counterparts. Further, the Amish are less likely to engage in leisure-time physical activity or in exercise associated with attempts to lose weight or deal with hypertension. Amish women are less likely to use seat belts than non-Amish women, whereas men in both groups appear rather similar. Although some differences could be influenced by response biases, many are supported by less systematic observations of Old Order Amish societies. The patterns of health behavior reflect characteristics of Amish culture and may be responsible for certain favorable mortality rates among the Amish population.     

Transient risk factors for acute childhood diarrhoea in an urban community of Papua New Guinea

Transient risk factors may play an important role in the aetiology of acute diarrhoea. These factors have not been well elucidated. To assess them, we monitored 479 children below the age of 5 years living in a well-defined urban community in Port Moresby, Papua New Guinea, for one year, using the nested case-control method with density sampling. Comparing the odds ratios, we found that eating food that had been kept for more than 12 h, eating away from home, temporary absence of mother from home for more than one day, and the presence of respiratory infection in the child, were statistically associated with an increased risk of diarrhoea. We conclude that these transient factors must be addressed if effective control of diarrhoea is to be achieved. We believe that further studies will identify the factors more precisely and provide a better understanding of the method we have employed.     

Bloodborne pathogen exposure risk among surgeons in sub-Saharan Africa.

To document the frequency and circumstances of bloodborne pathogen exposures among surgeons in sub-Saharan Africa, we surveyed surgeons attending the 2006 Pan-African Association of Surgeons conference. During the previous year, surgeons sustained a mean of 3.1 percutaneous injuries, which were typically caused by suture needles. They sustained a mean of 4.1 exposures to blood and body fluid, predominantly from blood splashes to the eyes. Fewer than half of the respondents reported completion of hepatitis B vaccination, and postexposure prophylaxis for human immunodeficiency virus was widely available. Surgeons reported using hands-free passing and blunt suture needles. Non-fluid-resistant cotton gowns and masks were the barrier garments worn most frequently.     

Tuberculosis in Lebanese jails: Prevalence and risk factors

A survey was conducted in 1995 to assess the prevalence of TB infection using the PPD skin test infection among 3931 inmates in all 21 jails in Lebanon. Forty-five percent of participants had a positive PPD skin test. The likelihood of testing positive was higher among men versus women, and among those who had been incarcerated for more than 3years versus less than that. Compared to prisoners whose usual residence was Central Lebanon, those from North Lebanon and those from outside Lebanon (mostly Syria and Egypt) had a higher risk for PPD positivity, those from Bekaa a lower risk, and those from South Lebanon about the same risk. Among those with positive PPD tests, 7% had abnormal chest X-rays suggestive of active infection. Results suggest that TB infection is an important health problem in correctional facilities in Lebanon and that special control programs should target North Lebanon. The importance of screening the incarcerated population with chest X-rays rather than PPD skin tests is discussed.     

Lead exposure in an urban community: investigation of risk factors and assessment of the impact of lead abatement measures

INTRODUCTION: A battery recycling plant located in an urbanized area contaminated the environment with lead oxides. The Secretary of Environment of the State of S?o Paulo demanded an evaluation of lead exposure among the population in the vicinity of the plant. OBJECTIVES: To assess the lead exposure of children, to propose control measures and evaluate the impact of these measures. METHODS: Cross-sectional study of all children<13 years old in a radius of 1km from the plant responsible for the contamination. Blood lead levels (BLL) were determined for each child and questionnaires were applied to their parents. Mean BLL were compared before and after control measures were implemented. Logistic regression identified risk factors of lead exposure. RESULTS: Of the 850 investigated children, 311 presented BLL above the action limit established by the World Health Organization. Overall, the median BLL was 7.3 micro g/dL and it varied according to age of children (higher among 1-5 years old) and distance of the residence from the plant. Risk factors identified for BLL>10 micro g/dL were: to live in unpaved areas, parent working in the plant, distance from the plant, to play on the ground, pica, and to drink locally produced milk. After control measures were implemented (closing the plant, soil removal, dust vacuum-cleaning in the households, etc.), a reduction of 46% in BLL was observed considering the 241 re-evaluated children with levels >10 micro g/dL. CONCLUSIONS: This study showed that combined abatement measures were effective in reducing BLL in children living close to a contaminating source. These results informed the decision-making process regarding management of contaminated areas in Brazil.     

Swimmer's itch: incidence and risk factors

Swimmer's itch (cercarial dermatitis) affects people engaged in open-water activities. We report incidence and risk factors for a US lake. Water exposures and swimmer's itch experience were reported daily for riparian household residents and guests at Douglas Lake, Michigan, in July 2000. Incidence of swimmer's itch was 6.8 episodes per 100 water exposure days. Positive risks were (1) exposures in shallow water and in areas with onshore winds and (2) more days of lake use in July. Further epidemiological studies will help public health agencies address this bothersome problem at recreational lakes.     

Condoms in sub-Saharan Africa

Sub-Saharan Africa (SSA) is the region with the world's highest rates of HIV and other sexually transmissible infections (STIs), yet numerous studies show that condom use is generally rare. This suggests a need for a better understanding of how condoms fit within sexual practices and relationships in SSA. This paper seeks to address this need by reviewing research published between the late 1980s and 2011 on use and factors influencing use of male condoms in SSA. What is evident from this research is that condom use involves complex social and interpersonal dynamics, with structural and cultural conditions exerting an influence through framing social cognitions and setting boundaries on autonomy that make the apparently irrational choice of eschewing condoms a rational decision. The influences of poverty; relationships with parents, peers and partners; limited, insufficient or absent information especially in rural areas and among men who have sex with men; gender and sexual norms, and the dynamics of gendered power; and beliefs and attitudes about HIV, condoms and sexuality all have been shown to work against condom use for a large proportion of Africa's people. However, promising results are shown in trends towards increased condom use among single women in numerous countries, increasing acceptance and use of condoms among some university students, successes in producing potentially sustainable condom use resulting from select interventions, and resistance to succumbing to the dominant gender-power dynamics and structural-cultural impediments that women in groups have mobilised.     

21st century research in urban WASH and health in sub-Saharan Africa: methods and outcomes in transition

Tackling global inequalities in access to Water, Sanitation and Hygiene (WASH) remains an urgent issue – 58% of annual diarrhoeal deaths are caused by inadequate WASH provision. A global context of increasing urbanisation, changing demographics and health transitions demands an understanding and impact of WASH on a broad set of health outcomes. We examine the literature, in terms of health outcomes, considering WASH access and interventions in urban sub-Saharan Africa from 2000 to 2017. Our review of studies which evaluate the effectiveness of specific WASH interventions, reveals an emphasis of WASH research on acute communicable diseases, particularly diarrhoeal diseases. In contrast, chronic communicable and non-communicable health outcomes were notable gaps in the literature as well as a lack of focus on cross-cutting issues, such as ageing, well-being and gender equality. We recommend a broader focus of WASH research and interventions in urban Africa to better reflect the demographic and health transitions happening.

Abbreviations: CBA: Controlled Before and After; GSD: Government Service Delivery; IWDSSD: International Drinking-Water, Supply and Sanitation Decade (IDWSSD); KAP: Knowledge, Attitudes and Practices; IBD: Irritable Bowel Diseases; MDG: Millennium Development Goals; NTD: Neglected Tropical Diseases; PSSD: Private Sector Service Delivery; SDG: Sustainable Development Goals; SSA: Sub Saharan Africa; SODIS: Solar Disinfection System; STH: Soil Transmitted Helminths; RCT: Randomised Control Trial; WASH: Water Sanitation and Hygiene; WHO: World Health Organization     

Mapping urban physical distancing constraints,sub-Saharan Africa: a case study from Kenya

With the onset of the coronavirus disease 2019 (COVID-19) pandemic, public health measures such as physical distancing were recommended to reduce transmission of the virus causing the disease. However, the same approach in all areas, regardless of context, may lead to measures being of limited effectiveness and having unforeseen negative consequences, such as loss of livelihoods and food insecurity. A prerequisite to planning and implementing effective, context-appropriate measures to slow community transmission is an understanding of any constraints, such as the locations where physical distancing would not be possible. Focusing on sub-Saharan Africa, we outline and discuss challenges that are faced by residents of urban informal settlements in the ongoing COVID-19 pandemic. We describe how new geospatial data sets can be integrated to provide more detailed information about local constraints on physical distancing and can inform planning of alternative ways to reduce transmission of COVID-19 between people. We include a case study for Nairobi County, Kenya, with mapped outputs which illustrate the intra-urban variation in the feasibility of physical distancing and the expected difficulty for residents of many informal settlement areas. Our examples demonstrate the potential of new geospatial data sets to provide insights and support to policy-making for public health measures, including COVID-19.     

Stomach cancer incidence in Brazil: an ecologic study with selected risk factors

Contrary to many industrialized countries in which a sharp decline in stomach cancer incidence has been observed, Brazil still shows intermediate to high incidence rates. An ecologic analysis was performed to explore variables possibly associated with the development of stomach cancer. Cluster analysis, principal component analysis, and factor analysis were carried out with population data, including the following: stomach cancer incidence rates in the early 1990s obtained from population-based cancer registries in Porto Alegre, Campinas, Fortaleza, Belém, and Goiania; and data from a Brazilian national survey on family expenditures (several diet consumption items and availability of home refrigerators) carried out in 1974-75. The results suggested that past availability of a home refrigerator, i.e. food preservation, may have played an important role in currently observed differences in stomach cancer incidence among the various populations studied in Brazil. Differences in living standards among populations in these cities also appear to have played an important role in the observed incidence differences.     

Population-level effect of potential HSV2 prophylactic vaccines on HIV incidence in sub-Saharan Africa

Herpes simplex virus type-2 (HSV2) infection increases HIV transmission. We explore the impact of a potential prophylactic HSV2 vaccination on HIV incidence in Africa using STDSIM an individual-based model. A campaign that achieved 70% coverage over 5 years with a vaccine that reduced susceptibility to HSV2 acquisition and HSV2 reactivation by 75% for 10 years, reduced HIV incidence by 30–40% after 20 years (range 4–66%). Over 20 years, in most scenarios fewer than 100 vaccinations were required to avert one HIV infection. HSV2 vaccines could have a substantial impact on HIV incidence. Intensified efforts are needed to develop an effective HSV2 vaccine.     

HIV-1 seroprevalence and risk behaviors in an urban African-American community cohort.

OBJECTIVES. Previous attempts at obtaining population estimates of human immunodeficiency virus type 1 (HIV-1) seroprevalence have been beset by problems of cooperation bias. As part of the fourth round of study with an urban African-American community cohort, the following investigation was aimed at assessing HIV-1 prevalence and the relative importance of sex and drug injection as risk factors in infection. METHODS. Personal interviews were conducted in the home with 364 respondents, followed by voluntary blood sample collection from 287 of these individuals. RESULTS. Blood assays showed a point prevalence of 8.4% HIV-1 seropositivity in this community cross section, with a higher female-to-male ratio than appears among acquired immunodeficiency syndrome (AIDS) case reports. Most infected persons were unaware and unsuspecting of their infection. CONCLUSIONS. First, findings underscore the need to focus on risk behaviors rather than on risk groups. Second, the smaller than 2:1 ratio of infected men to women suggests that current AIDS case reports seriously underestimate HIV-1 infection among certain cohorts of African-American women. Finally, widespread ignorance of own infected status and inaccurate risk assessment signal the substantial task for community health educators in reaching inner-city African-American men and women at risk.