No increase in gonorrhea resistance seen after DoxyPEP trial

News brief

Research presented at this week's Conference on Retroviruses and Opportunistic Infections (CROI) suggests that the use of doxycycline after sex to prevent sexually transmitted infections (STIs) may not significantly increase resistance to the antibiotic.

According to reporting by UK-based charity NAM, analysis of Neisseria gonorrhoeae isolates from participants in the DoxyPEP study—which found that taking doxycycline postexposure prophylaxis (PEP) significantly reduced incidence of gonorrhea, syphilis, and chlamydia in gay and bisexual men and transgender women—did not find markedly increased doxycycline resistance among those who were taking doxycycline and were diagnosed as having gonorrhea during follow-up. Of the 20 gonorrhea samples from people on PEP, only 2 showed high-level resistance to doxycycline.

The analysis revealed, however, a significant increase in doxycycline-resistant Staphylococcus aureus (from 5% to 13%) in participants on PEP.

The DoxyPEP trial, which was stopped early because of the positive results, found that taking a dose of doxycycline within 72 hours of unprotected sex reduced syphilis by 87%, chlamydia by 88%, and gonorrhea by 55% in HIV-negative participants who were taking HIV pre-exposure prophylaxis (PrEP). The results were announced at the 2022 International AIDS Conference.

Following the presentation of the data, the US Centers for Disease Control and Prevention said it would collaborate with trial investigators and other partners to develop interim clinical guidance and outline key additional considerations. One of those considerations was data on the change in doxycycline resistance in other common bacteria found in or on the body.

Trial: Stewardship intervention cuts antibiotic prescribing for suspected urinary infections

News brief

Chris Dall, MA

hands of elderly man taking pills A randomized controlled trial in four European nations found that implementing a multifaceted antibiotic stewardship intervention safely reduced antibiotic prescribing for urinary tract infections (UTIs) in frail older adults, researchers reported today in The BMJ.

In the cluster randomized trial, healthcare providers at 38 clusters of one or more general practices and older adult care organizations in Poland, the Netherlands, Norway, and Sweden were assigned to provide usual care or receive a multifaceted intervention consisting of a decision tool for appropriate antibiotic use for UTIs in frail older adults, supported by a toolbox with educational material. A participatory-action-research approach was used, with sessions for education, evaluation, and local tailoring of the intervention.

The primary outcome of the study, which included 1,041 frail adults aged 70 or older, was the number of antibiotic prescriptions for suspected UTIs per person per year. Data collection took place during a 5-month baseline period and a 7-month follow-up period.

Our multifaceted antibiotic stewardship intervention can be recommended for use in clinical practice to reduce antibiotic use for suspected urinary tract infections in frail older adults.

In the baseline period, the number of antibiotic prescriptions for suspected UTIs was 0.50 per person-year in the intervention group and 0.44 in the control group. During the follow-up period, that number fell to 0.27 per person-year in the intervention group and climbed to 0.58 in the control group. When adjusted for potential confounders, the patients in the intervention group had a 58% lower rate of receiving an antibiotic prescription for a suspected UTI compared with patients in the control group, with a rate ratio of 0.42 (95% confidence interval [CI], 0.26 to 0.68).

No differences between the intervention and control group were observed in the incidence of complications (less than 0.01 vs 0.05 per person-year), hospital referrals (less than 0.01 vs 0.05), admissions to hospital (0.01 vs 0.05), mortality within 21 days of suspected UTI (0 vs 0.01), and all-cause mortality (0.26 vs 0.26).

"Our multifaceted antibiotic stewardship intervention can be recommended for use in clinical practice to reduce antibiotic use for suspected urinary tract infections in frail older adults," the study authors concluded.

FDA begins priority review of Pfizer RSV vaccine for maternal use

News brief

Lisa Schnirring

Pfizer yesterday announced that the US Food and Drug Administration (FDA) has accepted it licensing application, which starts the review of its candidate respiratory syncytial virus (RSV) vaccine (RSVpreF) for use in pregnant women to help protect babies against the virus.

In a press release, Pfizer said the FDA's review will be done on a priority basis and that the agency expects a decision in August. In December, the FDA granted priority review of the vaccine for use in older adults.

Pfizer said the data supporting use in pregnant women comes from promising results from a phase 3 trial, which it will present to the Centers for Disease Control and Prevention vaccine advisory group tomorrow.

If approved, RSVpreF would help protect infants at their first breath from the devastating effects of this infectious disease.

RSV, a common and contagious respiratory illness, can cause severe disease in infants, older people, and others who have underlying health conditions. RSV bronchiolitis—a cause of respiratory distress that is sometimes fatal—is the leading cause of infant hospitalization due to viral illness. Currently, there is no RSV vaccine, and treatment options are limited.

Annaliesa Anderson, PhD, senior vice president and chief scientific officer in vaccine research and development at Pfizer, said, "If approved, RSVpreF would help protect infants at their first breath from the devastating effects of this infectious disease, which, though well-known, has been particularly evident throughout this RSV season."