by Jeffrey T. Kirchner, DO, AAHIVS, AAHIVM Chief Medical Officer
November 17, 2020
Rearigh L et al. Surprisingly Low Levels of Measles Immunity in Persons With HIV: A Seroprevalence Survey in a United States HIV Clinic. Open Forum Infectious Diseases, October 2020. Volume 7, Issue 10. https://doi.org/10.1093/ofid/ofaa428
Despite a statement in 2000 that measles had been eliminated in the U.S. outbreaks continue to occur. In 2019, there were 1,282 cases of measles reported from 31 states. This resurgence is mainly due to declining vaccination rates, but also fluctuating herd immunity and post-vaccination antibody decline. Due to underlying immune dysfunction, persons with HIV (PWH) who contract measles are at increased risk of complications. This study looked at the presence of measles IgG antibody in PWH receiving care at an academic clinic in Nebraska. There were 351 patients evaluated of whom 77% were male. The mean age was 48 years and the mean CD4 nadir for the group was 334 cells/mm3. At the time of measles antibody testing, 86% of those testing negative and 87% testing positive had undetectable HIV-RNA levels. The measles antibody seroprevalence rate in this cohort was only 70%. Younger age (<45 years) and birth after 1957 were both significantly associated with measles seronegativity. Having a documented history of measles infection was associated with IgG seropositivity. This study found a measles seroprevalence rate much lower than previously reported in PWH. This level of seropositivity is also considerably lower than the 95% rate needed to maintain herd immunity.
The finding that only 70% of this HIV patient population was immune to measles is cause for concern. There is little data on measles antibody seroprevalence in PWH and a Pubmed search revealed only 3 other studies, including the one cited above from 1992 which showed a 95% seropositivity. A two-dose series of MMR is currently recommended for PWH (without evidence of immunity) provided they have a CD4 count ≥200 cells/mm3. If further seroprevalence studies of measles in PWH show low levels of immunity, it may be appropriate to provide routine MMR. I believe this study supports antibody screening for PWH who are at risk of measles exposure. This includes: healthcare workers,students at post-high school educational institutions, international travelers, and others at increased risk during a measles outbreak.A report released jointly by the CDC and WHO on November 12 noted that cases increased to 869,770 and 207,500 people died worldwide from measles in 2019.
The author has no conflicts of interest to disclose.
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