Shortages of nurses, doctors, and health professionals in resource-poor countries challenge the success of many health initiatives and health-system strengthening. In many of these countries, medical and nursing schools are few and severely short of faculty, limiting their capacity to scale-up and increase the number of skilled graduates and professionals to support the health system.

The medieval Black Death (c. 1347-1351) was one of the most devastating epidemics in human history. It killed tens of millions of Europeans, and recent analyses have shown that the disease targeted elderly adults and individuals who had been previously exposed to physiological stressors. Following the epidemic, there were improvements in standards of living, particularly in dietary quality for all socioeconomic strata.

Human African trypanosomiasis, better known as sleeping sickness, nowadays ranks among the more neglected diseases in the countries of Africa where it is found. Though it still kills many people every year, it cannot compete for celebrity with such major killers as malaria and AIDS. Yet that was not always the case. A hundred years ago, sleeping sickness attracted considerable scientific research and political attention because of its importance to the conquest of sub-Saharan Africa by the European colonial powers.

In March 2014, the World Health Organization was notified of an outbreak of a communicable disease characterized by fever, severe diarrhea, vomiting, and a high fatality rate in Guinea. Virologic investigation identified Zaire ebolavirus (EBOV) as the causative agent. Full-length genome sequencing and phylogenetic analysis showed that EBOV from Guinea forms a separate clade in relationship to the known EBOV strains from the Democratic Republic of Congo and Gabon.