HIV incidence in the United States declined by approximately 26% since 2003, based on a study using a new and simple method of estimating the number of new cases.
“Previously, the number of newly diagnosed HIV cases in a year was used as a proxy measure for HIV incidence but has never been used as the sole data source to calculate HIV incidence, because HIV infection can remain asymptomatic for many years and newly reported cases represent both recent and long-standing infections,” wrote Qiang Xia, MD, of the New York City Department of Health and Mental Hygiene, and coauthors.
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The researchers divided the period of study from 2002-2011 into 3-year intervals with overlaps, and estimated HIV incidence based on the assumption that all HIV infections would be diagnosed through testing or death and that HIV incidence and case findings were stable within each 3-year period. HIV incidence was then defined as the number of new HIV infections in a year, and the number of new diagnoses in the previous year, current year, and following year were used to calculate each current year.
The study was limited by several factors, including the accuracy of HIV case reporting and the stability of HIV case finding within the 3-year periods, the researchers wrote. However, the findings suggest that the “CDC may have overestimated HIV incidence and HIV incidence in the United States may have been declining since 2003,” the coauthors said. “We should consider all available methods, rather than relying on one, to provide more accurate estimates of HIV incidence to guide our intervention programs,” they added.
The researchers had no financial conflicts to disclose.
Find the full study in the Journal of Acquired Immune Deficiency Syndromes (JAIDS. 2016 Sep 19;138:e20154664. doi: 10.1097/QAI.0000000000001185).