Study in LA highlights real-world efficacy of doxyPEP

News brief

A study of more than 2,000 patients in Los Angeles who were prescribed doxycycline post-exposure prophylaxis (DP) found it was highly effective in preventing sexually transmitted infections (STIs), researchers reported last week in Open Forum Infectious Diseases.

For the study, conducted at the Los Angeles LGBT Center from April 2019 to July 2024, researchers analyzed electronic health record data on 2,083 patients who were prescribed DP over the study period. The center issued formal clinician guidance on DP use in October 2022. The aim of the study was to review patient demographics, STI testing history, use patterns, and short-term effectiveness of DP.

Nearly half of the patients were between 31 and 40 years of age (48.1%), over half were white (55.9%), 85.2% were gay or bisexual men, and 41.4% had a history of one or more STI diagnoses in the year prior to DP initiation. Nearly a quarter (24.5%) of DP patients received a prescription from January 1 to April 15, 2024.

Real-world efficacy matches clinical trial results

Among 1,115 patients with 6 months or more of DP use, cases of syphilis fell by 86.4%, chlamydia cases declined by 89.7%, and gonorrhea cases decreased by 54.7%. There was similar effectiveness for chlamydia and gonorrhea regardless of anatomic site (rectal or throat swabs or urine sample).

The study authors note that the reduction in bacterial STIs observed among DP users is similar to the results of the DoxyPEP trial conducted in San Francisco and Seattle. Results from that trial and another in France resulted in the Centers for Disease Control and Prevention recommending DP in 2024 for gay men and transgender women with a history of STIs.

The authors say that while DP has become "an important and ever more widely used tool" for bacterial STI transmission, important questions about possible tradeoffs or consequences of consistent use remain.

"Researchers should closely examine use patterns and establish quality improvement programs in all settings where DP use is recommended in order to minimize adverse outcomes while trying to achieve population impact on the STI and HIV syndemics," they concluded.

Wyoming reports its first human H5N1 avian flu infection

News brief

Mary Van Beusekom, MS

Close-up of chicken — Olivier Duval / Flickr cc

A woman living in Platte County has contracted Wyoming's first case of H5N1 avian flu and is the fourth American to be hospitalized for the virus, the Wyoming Department of Health (WDH) confirmed late last week.

The infected woman is hospitalized in another state, is older, has underlying medical conditions, and was likely exposed to H5N1 through contact with her infected backyard poultry flock. "H5N1 has been known to be infecting wild birds in Wyoming for some time now with the currently circulating virus spreading nationally since 2022," the WDH said in a press release. "Infections among poultry and dairy cattle have also occurred previously in Wyoming."

While this is a significant development as bird flu activity is monitored in Wyoming and across the country, it is not something we believe requires a high level of concern among most Wyoming residents.

Alexia Harrist, MD, PhD

A total of 70 people are now known to have been infected with H5N1 in the United States in the past year, most of whom had contact with sick poultry or cattle. Most cases have been mild, although a patient in Louisiana died.

"While this is a significant development as bird flu activity is monitored in Wyoming and across the country, it is not something we believe requires a high level of concern among most Wyoming residents," Alexia Harrist, MD, PhD, state health officer and WDH epidemiologist, said.

Risk to people considered low

No human-to-human H5N1 transmission has been documented, and officials have followed up with people exposed to the patient and flock, Harrist said. "Experts continue to track the spread of H5N1 through wild birds, poultry and dairy cattle across the country," she said. " A small number of people have also been infected. Unfortunately, this patient's experience has been much more serious."

She advised against eating raw or undercooked meat or eggs, handling sick wild or domestic birds, and consuming raw (unpasteurized) milk or dairy products.

CWD hits 2nd Wyoming elk feeding ground in previously unaffected hunt area

News brief

Mary Van Beusekom, MS

Two female elk — David Burnett / Flickr cc

The Wyoming Game and Fish Department (WGFD) has confirmed the first cases of chronic wasting disease (CWD) in Elk Hunt Area 87, which also mark the first detections in the Upper Green River elk herd and the second time the disease been found on a state elk feeding ground.

The two adult female elk were found dead in January and early February, respectively, at the Dell Creek feeding ground. Elk Hunt Area 87, located in the Pinedale region in the western part of the state, abuts CWD-positive elk hunt areas 84 and 92.

It is unfortunate and concerning to find CWD on an elk feedground.

Justin Binfet

The first elk to test positive on a Wyoming feeding ground was identified in late December. That case was reported on the Scab Creek feeding ground in Sublette County, which is also in the Pinedale region and abuts Elk Hunt Area 92.

"It is unfortunate and concerning to find CWD on an elk feedground," WGFD Wildlife Division Deputy Chief Justin Binfet said late last week in a news release. "However, it was not unexpected given this disease continues to spread throughout the West."

First feeding ground CWD-management plans

Binfet added that the WGFD is developing the first Feedground Management Action Plans (FMAPs) for the Pinedale and Jackson herds to guide wildlife managers as they work to mitigate CWD transmission and reduce elk reliance on these areas. "After completing the initial FMAP process for the Pinedale Herd, the Region will determine which herd to prioritize next," the news release said.

CWD, a fatal neurodegenerative disease caused by misfolded proteins called prions, can spread among cervids such as deer, elk, and moose and through environmental contamination. The disease isn't known to infect people, but experts fear it could cross the species barrier.

Quick takes: New Mexico measles outbreak; FDA clears chikungunya, meningococcal vaccines

News brief

Lisa Schnirring

The New Mexico Department of Health (NMDOH) has declared a measles outbreak, following the confirmation of illnesses in two Lea County adults. In a February 14 statement, the agency said Lea County now has three cases. Lea County borders a Texas county that is in the midst of a quickly growing outbreak. The NMDOH said a connection to the rapidly growing outbreak in Gaines County, Texas, is suspected but hasn't been confirmed. Exposures for the recent cases were reported at a variety of locations, including a school, a grocery store, a church, a pharmacy, and a hospital emergency department. Elsewhere, the New Jersey Department of Health on February 14 reported a measles infection in a resident of Bergen County who had recently traveled internationally. It is working with local officials on contact tracing and contacting people who may have been exposed.
Bavarian Nordic (BN) announced that the US Food and Drug Administration (FDA) has approved its recombinant virus-like-particle single-dose vaccine against chikungunya, which can be used in people as young as 12 years old. In a February 14 statement, BN said the FDA approved Vimkunya as part of a priority review, based on two phase 3 clinical trials in people ages 12 and older. The company said the vaccine, expected to be commercially available in the first half of 2025, fills an unmet need for chikungunya prevention in young travelers. The BN vaccine is the second FDA approved vaccine for chikungunya. In November 2023, the FDA approved the nation's first, a live-attenuated single-dose vaccine from Valneva, which is indicated for adults who are at increased risk of the disease. A few months later, the US Centers for Disease Control and Prevention (CDC) recommended it for people who will be traveling to countries or territories reporting outbreaks. The CDC's Advisory Committee on Immunization Practices (ACIP) is expected to consider a recommendation for the BN vaccine at its next meeting on February 26.
GSK announced that the FDA has approved its meningococcal vaccine that protects against five Neisseria meningitidis serogroups for people ages 10 to 25 years old. The vaccine combines the antigenic components of GSK's two current meningococcal vaccines: Bexsero, which targets group B, and Menveo, which targets groups A, C, Y, and W-135. GSK said in a February 15 news release that the approval was supported by results from two phase 3 trials that looked at safety, tolerability, and immune response in more than 4,800 participants. The company said the five-in-one vaccine is positioned to simplify meningococcal vaccine delivery and help protect more US adolescents against the five most common subgroups. It said ACIP is expected to vote on a recommendation for the vaccine on February 26.