A9 HIV subtype diversity across geography and transmission groups in Maryland
Year: 2018
Type: article
Study design: Observational Study
Abstract: The distribution of HIV subtypes within a local epidemic can provide insight into social dynamics underlying transmission patterns and inform treatment and prevention strategies. Subtype B predominates in most US regions, but non-B infections are increasingly evident in Maryland and large-scale examinations of subtype diversity are lacking. In 2014, Maryland HIV case surveillance began systematically collecting HIV genotypic sequence data to identify outbreaks and transmission patterns. We used sequences collected through 2015 to examine geographic and transmission group distribution associated with different HIV subtypes. HIV-1 pol sequences were aligned with Los Alamos HIV Database subtype reference sequences and subtyped using HIV-TRACE at a distance cutoff optimized for accurately identifying subtype B data (5 per cent). Non-B sequences were subsequently classified using the REGA HIV-1 Subtype Tool. All sequence subtypes were matched to data within the HIV case surveillance database for descriptive analysis. HIV sequences were available from 7,045 individuals between 2004 and 2015, ∼20 per cent of all persons living with HIV in 2015. Subtype B accounted for 95.7 per cent of all sequences overall and 90.2 per cent of those from persons diagnosed in 2014. The most common non-B subtypes were subtype G, C, A, and D, and a variety of circulating recombinant forms. The proportion of non-B sub-types increased from 0 to 2 per cent of new annual diagnoses prior to 2000 to 7 to 9 per cent after 2010, particularly in the Central and Suburban regions. The highest frequency of non-B (4.3–25.5 per cent) was seen in five counties across the state. In contrast, <1 per cent of sequences from Baltimore City were non-B. Those with subtype B were 27.6 per cent heterosexual, 27.6 per cent people who inject drugs, and 25.2 per cent men who have sex with men (MSM). Non-B subtypes were primarily heterosexual (60.6 per cent), with increasing proportion among MSM after 2006. The large number of non-B subtypes likely reflects immigration patterns to the DC area. Non-B HIV is increasingly moving outside of DC and has been identified in some MSM and IDU cases. Increasing HIV viral diversity, including the potential for subtype recombination, across the state of Maryland poses challenges for clinical and preventive response and suggests geographic and social dimensions of HIV transmission patterns that require further examination.
Source: Virus Evolution
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,304
OpenAlex ID: W2800036223