Most studies of the association between family structure and risky sexual behaviour among adolescents and young adults have employed a risk perspective which assumes that, compared with other types, two-parent families are protective. Drawing from a positive-oriented approach in this study, it is hypothesized that within each family type some influential factors may mitigate such anticipated deleterious effects of non-intact families and decrease sexual risk-taking. The paper examines specifically the effects of risk and protective factors with an emphasis on family processes associated with resilience, using data from a pooled sample of 1025 females and males aged 12–24 years from Bandjoun (West Cameroon). Findings show that the quality of parent/guardian–youth relationships significantly decreases the odds of risky sexual behaviour by 36%, 65% and 50% in neither-, one- and two-parent families, respectively. For two-parent families only, parental control acts as a significant protective factor; it decreased by 41% the odds of risky sexual behaviour. Programmatically, protective family factors such as parent/guardian–youth interactions need to be promoted to improve the efficiency of reproductive health and HIV interventions in sub-Saharan Africa.

The objective of this paper is to identify demographic, social and behavioural risk factors for HIV infection among men in Zambia. In particular, the role of alcohol, condom use and number of sex partners is highlighted as being significant in the prevalence of HIV. Multivariate logistic regressions were used to analyse the latest cross-sectional population-based demographic health survey for Zambia (2007). The survey included socioeconomic variables and HIV serostatus for consenting men (N=4434). Risk for HIV was positively related to wealth status. Men who considered themselves to be at high risk of being HIV positive were most likely to be HIV positive. Respondents who, along with their sexual partner, were drunk during the last three times they had sexual intercourse were more likely to be HIV positive (adjusted odds ratio (AOR) 1.60; 95% confidence interval (CI) 1.00–2.56). Men with more than two sexual life partners and inconsistent condom use had a higher risk for being HIV positive (OR 1.89, 95% CI 1.45–2.46; and OR 1.49, 95% CI 1.10–2.02, respectively). HIV prevention programmes in Zambia should focus even more on these behavioural risk factors.

This note categorizes the evidence for the hypothesis that mammalian offspring sex ratios (proportions male) are causally related to the hormone levels of both parents around the time of conception. Most of the evidence may be acknowledged to be correlational and observational. As such it might be suspected of having been selected; or of having been subject to other forms of bias or confounding; or, at any rate, of being inadequate as a firm basis for causal inference. However, there are other types of evidence that are not vulnerable to these types of criticism. These are from the following sources: (1) previously neglected data from Nazi Germany and Soviet Russia; (2) fulfilled predictions; (3) genetics; and (4) a network of logically (mathematically) related propositions, for some of which there is overwhelming empirical evidence. It is suggested that this variety of evidence confers greater overall credibility on the hypothesis than would be the case if all the evidence were of the same observational/correlational status. This observational/correlational evidence is tabulated to illustrate its consistency.

It is now widely recognized that a decentralized approach to the control of parasitic infections in rural sub-Saharan populations allows for the design of more effective control programmes and encourages high compliance. Compliance is usually an indicator of treatment success, but cannot be used as a measure of long-term benefit since re-infection will be strongly influenced by a number of factors including the social ecology of a community. In this paper qualitative and quantitative methods are used to identify and understand the structural and behavioural constraints that may influence water contact behaviour and create inequalities with respect to Schistosoma re-infection following anti-helminth drug treatment. The research is set in a community where participant engagement has remained uniformly high throughout the course of a 10-year multidisciplinary study on treatment and re-infection, but where levels of re-infection have not been uniform and, because of variations in water contact behaviour, have varied by age, sex and ethnic background. Variations in the biomedical knowledge of schistosomiasis, socioeconomic constraints and ethnic differences in general attitudes towards life and health are identified that may account for some of these behavioural differences. The observations highlight the benefits of understanding the socio-ecology of control and research settings at several levels (both between and within ethnic groups); this will help to design more effective and universally beneficial interventions for control and help to interpret research findings.

The increasing greying of India's population raises concerns about the welfare and health status of the aged. One important source of information of health status of the elderly is the National Sample Survey Rounds on Morbidity and Health Care Expenditure. Using unit-level data for 1995–96 and 2004, this paper examines changes in reported health status of the elderly in India and analyses their relationship with living arrangements and extent of economic dependency. It appears that even after controlling for factors like caste, education, age, economic status and place of residence, there has been a deterioration in self-perceived current health status of the elderly. The paper argues that, although there have been changes in the economic condition and traditional living arrangements – with a decline in co-residential arrangements – this is not enough to explain the decline in reported health status and calls for a closer look at narratives of neglect being voiced in developing countries.

Although desired family size is often different from actual family size, the dynamics of this difference are not well understood. This paper examines the patterns and determinants of the difference between desired and actual number of children (unmet fertility desires) among women aged 15–49 years using pooled data from the 1990, 1999 and 2003 Nigeria Demographic and Health Surveys (NDHSs). The results show that more than two-thirds of the sample have unmet fertility desires (18.1% have more while 52.4% have fewer than desired). It was found that early and late childbearing increased the odds of unmet fertility desires. Also, women with low levels of education, from poor households, rural residents as well as those who had experienced child death were at a higher risk of unmet fertility desires in the multivariate context. The study highlights the policy and programme implications of the findings.

In a recent paper in this Journal, I offered hypotheses on the offspring sex ratios of women infected with the parasite Toxoplasma gondii, and on the offspring sex ratios of people who are carriers of hepatitis B virus (HBV) (James, 2008). Subsequent research suggests that these hypotheses need amending. A detailed account of the amendments is given elsewhere in a specialized journal (James, 2010a). Here they are summarized.