Official websites use. Share sensitive information only on official, secure websites. Elsevier hereby grants permission to make all its COVIDrelated research that is available on the COVID resource centre - including this research content - immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source.
Wilson 1. The morbidity, mortality, and social disruption due to the acquired immunodeficiency syndrome AIDS pandemic weigh disproportionately upon resource-poor areas of the tropics. Such interactions are marked by epidemiologic complexity. The AIDS pandemic is best described as the sum of discontinuous and overlapping epidemics of disease among populations of variable and varying risk see Chapter The predominant modes of transmission of HIV perinatal, sexual, and parenteral result in a bimodal distribution of disease, with peaks among young children and young adults.
The risk of infection or disease due to tropical pathogens varies widely with differences in ecological, political, and socioeconomic conditions including access to medical care ; related specific host factors such as age of exposure, pregnancy, behavior, and nutrition; and host genetics. Disease due to a coinfecting pathogen may be due to primary infection, recurrent infection, or the reactivation of latent infection.
For some pathogens, the risk factor responsible for the acquisition of HIV may also be the risk factor responsible for the acquisition of the coinfecting pathogen. As a consequence of this epidemiologic complexity, both the prevalence and the expression of coinfection are variable across ecological, economic, political, behavioral, and cultural divides.
Infection with HIV can influence the natural history of infection with other pathogens through: 1 facilitating infection; 2 altering the incidence of disease by increasing the ratio of disease to infection; 3 changing the presentation of disease; or 4 exacerbating the course of disease. Abnormalities of immune function are found in essentially every cellular and functional compartment of the immune system in AIDS, although profound defects in cell-mediated immunity CMI appear to be of greatest clinical importance.
