Respiratory Syncytial Virus and HIV—What's the Connection?
The number of RSV-infected adults in an African study who also had HIV was quite high, with the burden of HIV disproportionately in the young.
Respiratory Syncytial Virus (RSV) is a virus that infiltrates the lungs and airways. Nearly all children in the United States have contracted RSV by the age of 2, and it usually results in nothing more than a week or so of cold-like symptoms, although infants and older people are at greater risk of serious illness. Thousands of young children are hospitalized for RSV each year in the United States; worldwide, the disease kills 160,000 people yearly.
Due to a lack of research on the connection between RSV and HIV in locations where the latter infection is prevalent, a team of scientists from the National Institute for Communicable Diseases and the University of the Witwatersrand, both in Johannesburg, South Africa, along with scientists from additional South African health entities, conducted a study to determine how HIV might be linked with the frequency and severity of RSV-associated severe acute respiratory illness (SARI) in South African adults.
The team studied data from February 2009 through December 2013, culled from hospitals in 4 South African provinces. During that time period, adults who had been experiencing symptoms of SARI for fewer than 7 days were screened and, in some cases, enrolled in a SARI surveillance program. Symptoms included sudden fever, cough, sore throat, and shortness of breath. Samples of their respiratory secretions were analyzed, and HIV testing was performed at the admitting physicians’ request. In total, 7872 patients were enrolled in the surveillance program, 99% of whom were given a test for RSV. HIV test results were also available for 89% of patients in the program.
Overall, the rate of RSV found in this population sample was fairly low—228 of the 5297 individuals who tested positive for HIV (4%) and 57 of the 1708 individual who were not infected with HIV (3%). However, of the small number of individuals who were found to have RSV, the overwhelming majority also were found to have HIV—228 out of 285, or 80%. The HIV burden among RSV-positive patients was disproportionately carried by the young: 87% of those co-infected were between the ages of 18 and 44, 73% were between the ages of 45 and 64, and just 21% were at least 65 years old. Fewer than half of surveillance-study participants who were found to be positive for HIV had begun antiretroviral treatment when admitted to the hospital.
Across all age groups, HIV-positive patients had higher rates of RSV-associated SARI than those who were not infected with HIV, and they were hospitalized more often, although there was no meaningful difference in the death rates between the two groups. One group that did experience a significant increase in mortality was the RSV-infected elderly, whether they had HIV or not. Three of the 4 elderly RSV patients who died also had HIV, and 2 had other underlying infections (excluding HIV or tuberculosis), although this is an admittedly small sample. In general, older individuals with RSV spent longer periods of time hospitalized than younger individuals with RSV.
One possible explanation for the large number of RSV-infected patients in the study who also had HIV is that HIV compromises the immune system, hampering the ability of the body to fight RSV. “Available evidence suggests that the immune response to RSV infection requires both humoral and cellular elements, specifically CD4+ and CD8+ T cells which are critical in terminating an acute RSV infection,” the authors wrote in the discussion section of the report. They also noted that some studies suggest inflammatory cells may contribute to and worsen RSV: “Individuals with compromise to their immune systems, like HIV-infected adults, may be more at risk of severe infection but the role of a decreased immune response may need further description.”
The authors concluded by asserting that, if available, the RSV vaccine should be given to older individuals and possibly those infected with HIV in order to reduce the number of RSV-related SARI hospitalizations, at least in Africa or other locales that have a high number of individuals with HIV.
Laurie Saloman, MS, is a health writer with more than 20 years of experience working for both consumer and physician-focused publications. She is a graduate of Brandeis University and the Medill School of Journalism at Northwestern University. She lives in New Jersey with her family.