According to the World Health Organization, many of the world’s developed countries consider 65 years as the chronological age when people are considered “elderly,” while the United Nations uses the ages of 60 and above. However, in parts of sub-Saharan Africa and elsewhere the cutoff age is often lower such as 50 or 55 years.
This month, PLOS Neglected Tropical Diseases published a new study by Rowe et al. from Singapore on dengue fever in the elderly (> 60 years of age). Among their interesting findings were that the elderly had longer hospital admissions, and had higher rates of pneumonia and urinary infections. Overall, the elderly had more dengue hemorrhagic fever and severe dengue.
The Rowe et al study intrigued me enough to try and do a casual search for other papers on neglected tropical diseases (NTDs) and their link with older populations. The number of papers on the subject is modest but they are all interesting. Among the helminth infections, the elderly frequently represent an at-risk population for blindness due to onchocerciasis. Human hookworm infection is a soil-transmitted helminthiasis that exhibits heavy worm burdens among both pediatric and adult populations, and in the 1990s we found that on Hainan Island China it was the elderly who had the highest hookworm burdens and prevalence of infection.
The United Nations Population Fund reports that populations are ageing around the world, both in developed and developing countries, and the percentage of elderly is accelerating. Among the factors promoting population ageing are lower fertility, increased child survival, and overall better health. Especially in the large middle-income countries such as India, Indonesia, and China where NTDs are already widespread it will be interesting to see how the clinical spectrum of these diseases might change in the context of an ageing population. Accordingly, PLOS NTDs welcomes papers on this dynamic subject.
In the past, we have published papers on other neglected populations, including a recent article on NTDs in aboriginal populations. The elderly constitute yet another important and emerging neglected population at risk for NTDs.