MMWR News Synopsis

Articles

Clusters of Rapid HIV Transmission Among Gay, Bisexual, and Other Men Who Have Sex with Men — United States, 2018–2021

CDC Media Relations
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A new CDC report underscores the importance of HIV cluster detection and response activities to better understand rapid HIV transmission among gay, bisexual, and other men who have sex with men (MSM). Responding swiftly to clusters is important to interrupting transmission. To better understand rapid HIV transmission among gay and bisexual men, CDC assessed clusters of rapid HIV transmission previously detected in 2018 and 2019. Of 38 large HIV clusters (comprised of more than 25 diagnosed HIV infections, as of December 2021), 29 (76%) were primarily among gay and bisexual men. The clusters were small when they were initially identified but, by 2021, had grown larger by a median of 9 HIV infections per year. The analysis also found that rapid HIV transmission occurred among Black/African American, Hispanic/Latino, and White gay and bisexual men; in different regions of the country; and in communities of varying size. The overall HIV transmission rate among these clusters was six times that of previously estimated national transmission rates. Findings suggest most large clusters of rapid HIV transmission occur among gay and bisexual men. This group continues to face significant stigma and barriers to accessing HIV-related services. Cluster detection and response activities are an important tool that can help jurisdictions understand local communities experiencing rapid HIV transmission and to tailor HIV interventions specifically to those communities, including diverse groups of MSM. These interventions should aim to reduce barriers and address stigma to provide the services needed to stop transmission in these groups.

Outbreak of Acute Gastroenteritis Among Rafters and Backpackers in the Backcountry of the Grand Canyon National Park, April-June 2022

CDC Media Relations
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Norovirus spreads easily, especially when people have close contact and less access to hand washing, such as while backpacking or rafting. The largest known norovirus outbreak in the Grand Canyon National Park backcountry occurred among at least 200 rafters and backpackers from April–June 2022. Norovirus outbreaks are common across the country, with about 1,000 occurring per year. During April 1–June 17, a total of 191 rafters and 31 backpackers reported symptoms of acute gastroenteritis such as vomiting (81%), diarrhea (68%), or nausea (64%). Evidence suggests that norovirus was the cause of illness. Early and rapid communication between The National Park Service, Coconino County Health and Human Services, CDC, and river outfitters allowed for tailored health education messages and quick implementation of outbreak control measures. Prevention and control of future norovirus outbreaks should include rapid illness reporting, symptom screening before the trip starts, strict compliance with hygiene and sanitation protocols, water disinfection, prompt separation of people who are ill, and minimization of intergroup interactions. Not all hand sanitizers work well against norovirus, so hand hygiene in these settings must include soap and water.

Previously Released: Two Cases of Monkeypox-Associated Encephalomyelitis — Colorado and the District of Columbia, July–August 2022

CDC Media Relations
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Previously Released: Health Care Personnel Exposures to Subsequently Laboratory-Confirmed Monkeypox Patients — Colorado, 2022

CDC Media Relations
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Previously Released: Monkeypox in a Young Infant — Florida, 2022

CDC Media Relations
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• Norovirus Outbreaks Reported Through NoroSTAT — 12 States, August 2012-July 2022 The number of norovirus outbreaks reported by 12 states during a 12-month period from 2021–2022 has returned to pre-COVID-19 pandemic levels, around 1,000 per surveillance year, compared to less than 400 during the prior 12-month period (2020–2021). In 2012, CDC established the Norovirus Sentinel Testing and Tracking Network (NoroSTAT) to improve timeliness and completeness of surveillance for norovirus outbreaks that occur in the United States. Outbreaks are defined as two or more cases of illness associated with a common exposure. Most outbreaks (82%) are spread by person-to-person contact with a person sick with norovirus, including shaking hands and touching their mouth, sharing food or eating utensils, or caring for sick people. The number of outbreaks reported by 12 states during the 2021–2022 surveillance year was nearly three times the number of outbreaks during the 2020–2021 surveillance year. Nonpharmaceutical interventions implemented during the early stages of the COVID-19 pandemic were likely effective in preventing norovirus outbreaks. As pandemic restrictions have relaxed, the number of norovirus outbreaks has returned to levels similar to pre-pandemic years. People can help prevent norovirus illness by thoroughly washing their hands with soap and water, avoiding food preparation until at least 48 hours after symptoms stop, and properly cleaning and disinfecting surfaces contaminated by vomit or diarrhea.

• Death Rates from Unintentional Falls Among Persons Aged ≥65 Years, by Age Group — National Vital Statistics System, United States, 1999–2020

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U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES

CDC works 24/7 protecting America’s health, safety and security. Whether diseases start at home or abroad, are curable or preventable, chronic or acute, or from human activity or deliberate attack, CDC responds to America’s most pressing health threats. CDC is headquartered in Atlanta and has experts located throughout the United States and the world.