Ebola Virus Dose Response Model for Aerosolized Exposures: Insights from Primate Data

This study develops dose–response models for Ebolavirus using previously published data sets from the open literature. Two such articles were identified in which three different species of nonhuman primates were challenged by aerosolized Ebolavirus in order to study pathology and clinical disease progression. Dose groups were combined and pooled across each study in order to facilitate modeling. The endpoint of each experiment was death. The exponential and exact beta-Poisson models were fit to the data using maximum likelihood estimation. The exact beta-Poisson was deemed the recommended model because it more closely approximated the probability of response at low doses though both models provided a good fit. Although transmission is generally considered to be dominated by person-to-person contact, aerosolization is a possible route of exposure. If possible, this route of exposure could be particularly concerning for persons in occupational roles managing contaminated liquid wastes from patients being treated for Ebola infection and the wastewater community responsible for disinfection. Therefore, this study produces a necessary mathematical relationship between exposure dose and risk of death for the inhalation route of exposure that can support quantitative microbial risk assessment aimed at informing risk mitigation strategies including personal protection policies against occupational exposures.     

Education,employment, and fertility in Kinshasa and prospects for changes in reproductive behavior

This paper examines fertility behavior of women in Kinshasa, Zaire's capital city with a population of roughly four million. We look at relationships linking women's education, employment, and fertility behavior (children ever born, age at first marriage, contraception, abortion, breastfeeding, and postpartum abstinence), using data from a 1990 survey of reproductive-age women. Other things equal, there are significant differences by educational attainment and by modern sector employment in lifetime fertility and in most of the proximate determinants as well. The results suggest that modern contraception and abortion are alternative fertility control strategies in Kinshasa, with abortion appearing to play an important role in contributing to the observed fertility differentials by education and employment. The dramatic increases that have taken place in women's access to secondary and higher education are likely to reduce fertility in the future, while the effects of Zaire's current economic and political crisis are uncertain. Our findings are consistent with some of the arguments of Caldwell et al. (1992) on a new type of fertility transition in sub-Saharan Africa. If Zaire seeks to lower fertility, policy efforts should be made to soften the impact of economic crisis on school enrollments and enhance opportunities for young women to remain in school, at least well into the secondary level. Policy should also seek to promote more effective marketing and delivery of modern family planning services, so as to induce women to substitute modern contraception for abortion as a means of controlling their fertility.