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Since May 2022, laboratory-confirmed cases of mpox have been reported across nonendemic countries including the United States, mostly among men who have sex with men (1,2). Persons experiencing homelessness (PEH) [...]

An important component underlying the disparity in HIV risk between race/ethnic groups is the preferential transmission between individuals in the same group. We sought to quantify transmission between different race/ethnicity groups and measure racial assortativity in HIV transmission networks in major metropolitan areas in the United States. We reconstructed HIV molecular transmission networks from viral sequences collected as part of HIV surveillance in New York City, Los Angeles County, and Cook County, Illinois. We calculated assortativity (the tendency for individuals to link to others with similar characteristics) across the network for three candidate characteristics: transmission risk, age at diagnosis, and race/ethnicity. We then compared assortativity between race/ethnicity groups. Finally, for each race/ethnicity pair, we performed network permutations to test whether the number of links observed differed from that expected if individuals were sorting at random. Transmission networks in all three jurisdictions were more assortative by race/ethnicity than by transmission risk or age at diagnosis. Despite the different race/ethnicity proportions in each metropolitan area and lower proportions of clustering among African Americans than other race/ethnicities, African Americans were the group most likely to have transmission partners of the same race/ethnicity. This high level of assortativity should be considered in the design of HIV intervention and prevention strategies.

BackgroundClusters of HIV diagnoses in time and space and clusters of genetically linked cases can both serve as alerts for directing prevention and treatment activities. We assessed the interplay between geography and transmission across the Los Angeles County (LAC) HIV genetic transmission network.MethodsDeidentified surveillance data reported for 8186 people with HIV residing in LAC from 2010 through 2016 were used to construct a transmission network using HIV-TRACE. We explored geographic assortativity, the tendency for people to link within the same geographic region; concordant time-space pairs, the proportion of genetically linked pairs from the same geographic region and diagnosis year; and Jaccard coefficient, the overlap between geographical and genetic clusters.ResultsGeography was assortative in the genetic transmission network but less so than either race/ethnicity or transmission risk. Only 18% of individuals were diagnosed in the same year and location as a genetically linked partner. Jaccard analysis revealed that cis-men and younger age at diagnosis had more overlap between genetic clusters and geography; the inverse association was observed for trans-women and Blacks/African Americans.ConclusionsWithin an urban setting with endemic HIV, genetic clustering may serve as a better indicator than time-space clustering to understand HIV transmission patterns and guide public health action.

BackgroundPublic health action combating human immunodeficiency virus (HIV) includes facilitating navigation through the HIV continuum of care: timely diagnosis followed by linkage to care and initiation of antiretroviral therapy to suppress viral replication. Molecular epidemiology can identify rapidly growing HIV genetic transmission clusters. How progression through the care continuum relates to transmission clusters has not been previously characterized.MethodsWe performed a retrospective study on HIV surveillance data from 5226 adult cases in Los Angeles County diagnosed from 2010 through 2014. Genetic transmission clusters were constructed using HIV-TRACE. Cox proportional hazard models were used to estimate the impact of transmission cluster growth on the time intervals between care continuum events. Gamma frailty models incorporated the effect of heterogeneity associated with genetic transmission clusters.ResultsIn contrast to our expectations, there were no differences in time to the care continuum events among individuals in clusters with different growth dynamics. However, upon achieving viral suppression, individuals in high growth clusters were slower to experience viral rebound (hazard ratio 0.83, P = .011) compared with individuals in low growth clusters. Heterogeneity associated with cluster membership in the timing to each event in the care continuum was highly significant (P

BackgroundTransgender women are among the groups at highest risk for HIV infection, with a prevalence of 27·7% in the USA; and despite this known high risk, undiagnosed infection is common in this population. We set out to identify transgender women and their partners in a molecular transmission network to prioritise public health activities.MethodsSince 2006, HIV protease and reverse transcriptase gene (pol) sequences from drug resistance testing have been reported to the Los Angeles County Department of Public Health and linked to demographic data, gender, and HIV transmission risk factor data for each case in the enhanced HIV/AIDS Reporting System. We reconstructed a molecular transmission network by use of HIV-TRAnsmission Cluster Engine (with a pairwise genetic distance threshold of 0·015 substitutions per site) from the earliest pol sequences from 22 398 unique individuals, including 412 (2%) self-identified transgender women. We examined the possible predictors of clustering with multivariate logistic regression. We characterised the genetically linked partners of transgender women and calculated assortativity (the tendency for people to link to other people with the same attributes) for each transmission risk group.Findings8133 (36·3%) of 22 398 individuals clustered in the network across 1722 molecular transmission clusters. Transgender women who indicated a sexual risk factor clustered at the highest frequency in the network, with 147 (43%) of 345 being linked to at least one other person (adjusted odds ratio [aOR] 2·0, p=0·0002). Transgender women were assortative in the network (assortativity 0·06, p

The Los Angeles County Department of Public Health established a surveillance system to identify complicated (advanced human immunodeficiency virus [HIV] or hospitalized) mpox cases. From 1 August to 30 November 2022, we identified 1581 mpox cases, of which 134 (8.5%) were complicated. A subset of 8 cases did not recover after either initiating or completing a course of oral tecovirimat. All 8 patients were HIV positive and had advanced HIV (CD4 count <200 cells/μL). We identified 8 distinct mutations previously associated with tecovirimat resistance in specimens collected from 6 patients. Ongoing surveillance of viral evolution requires close coordination between health departments and frontline providers. [ABSTRACT FROM AUTHOR]

Since May 2022, approximately 2,500 mpox cases have been reported in Los Angeles County (LAC), California. Beginning in May 2023, the LAC Department of Public Health observed a consistent increase in mpox cases after a prolonged period of low incidence. A total of 56 cases were identified during May 4-August 17, 2023. A minority of mpox patients were fully vaccinated (29%). One patient was hospitalized; no deaths were reported. Two cases of reinfection occurred, both of which were associated with mild illness. The increasing number of cases during this period was significant, as few other health departments in the United States reported an increase in mpox cases during the same period. The outbreak spread similarly to the 2022 U.S. mpox outbreak, mainly through sexual contact among gay, bisexual, and other men who have sex with men. Vaccination against mpox became available in June 2022 and has been shown to be effective at preventing mpox disease. This outbreak was substantially smaller than the 2022 mpox outbreak in LAC (2,280 cases); possible explanations for the lower case count include increased immunity provided from vaccination against mpox and population immunity from previous infections. Nonetheless, mpox continues to spread within LAC, and preventive measures, such as receipt of JYNNEOS vaccination, are recommended for persons at risk of Monkeypox virus exposure., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Abraar Karan received funding from the National Institutes of Health. Nicole M. Green reports serving as president of the Southern California Branch of the American Society for Microbiology. Mario J. Pérez reports institutional support from the Ryan White Program Parts A, B, MAI, and EHE and leadership in the National Coalition of STD Directors. No other potential conflicts of interest were disclosed.