Paxlovid may cut risk of stroke for at least 3 months after COVID diagnosis

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Paxlovid caplets in hand — *Anthony Quintano / Flickr cc*

The use of the oral antiviral nirmatrelvir-ritonavir (Paxlovid) was linked to a significantly lower risk of ischemic and hemorrhagic stroke and all-cause death for at least 3 months after mild to moderate COVID-19, according to a study published in the Journal of Medical Virology.

Researchers at Chung Shan Medical University in Taiwan used the electronic health records of 181,992 matched pairs of US adult long-COVID survivors infected in 2022 or 2023 and either treated with Paxlovid within 5 days of diagnosis or given usual care.

The average patient age was 57.3 years among Paxlovid recipients and 47.8 years in the non-Paxlovid group.

Older, obese adults also benefitted

Paxlovid use was tied to a significantly reduced risk of ischemic and hemorrhagic stroke (hazard ratio [HR], 0.85) and all-cause death (HR, 0.68) for at least 90 days after COVID-19 infection. The findings held across age, sex, body mass index (BMI), vaccination status, and underlying diseases such as high blood pressure, diabetes, and high cholesterol levels.

Shared decision-making should be incorporated into clinical practice to balance the risks and benefits of nirmatrelvir/ritonavir.

Older adults and those with metabolic conditions such as obesity also received significant benefits against stroke and death (HR, 0.81 and 0.86, respectively), regardless of vaccination status.

"SARS-CoV-2 disrupts glucose metabolism, impairs β-cell function, and triggers inflammation, leading to long-term metabolic disturbances and endothelial dysfunction," the study authors wrote. "By limiting viral replication and inflammation, Paxlovid may help mitigate metabolic disruptions and preserve vascular integrity, reducing stroke risk in high-risk populations."

The HR for stroke at 6-month follow-up was 0.67 and 0.51 for death. At 1-year follow-up, the HR was 0.75 for stroke and 0.58 for death. At 2 years, the HR was 0.83 for stroke and 0.67 for death.

"Shared decision-making should be incorporated into clinical practice to balance the risks and benefits of nirmatrelvir/ritonavir, taking into account the risk of severe COVID-19, age, comorbidities, prior infection, and potential disruptions to cardiovascular therapy, with alternative treatments considered if necessary," the researchers concluded.

Analysis suggests COVID-19 diminishes sperm quality

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Chris Dall, MA

A study in China has found that COVID-19 is associated with poor sperm quality, researchers reported earlier this month in Scientific Reports.

To investigate the impact of COVID-19 on sperm quality, researchers with the Center for Reproductive Medicine at China Medical University conducted two studies among male patients who had come to their fertility center to receive semen analysis from early December 2022, when China loosened its COVID rules, through late January 2023. In both studies, researchers compared semen parameters between those who had contracted COVID-19 and those who had not.

The cross-sectional study included 604 participants who could provide semen samples after COVID-19, while the longitudinal study included 140 COVID-19–positive participants who could provide samples from before and after the infection and 149 uninfected patients who could provide two consecutive semen samples over time.

Reduced sperm count and sperm motility

In the cross-sectional study, the COVID-19 exposure group demonstrated significantly lower total sperm count (159.58 × 10⁶ vs. 185.42 × 10⁶), lower percentage of grade A sperm (5.37% vs 8.45%), lower progressive motility (24.74 ± 14.96% vs 28.73 ± 16.65%), lower total motility (32.04 ± 18.03% vs 36.91 ± 20.86%), and higher sperm DNA fragmentation index (DFI; 17.50% vs 11.75%) than the controls.

In the longitudinal study, after the infection, patients showed lower total sperm count (131.80 × 10⁶ vs 173.63 × 10⁶), lower percentage of grade A sperm (2.61% vs 8.50%), lower progressive motility (19.82 ± 13.68% vs 24.88 ± 14.97%), lower total motility (26.64 ± 17.35% vs 32.25 ± 18.69%), and higher DFI (32.10 ± 21.30% vs 26.49 ± 18.54%) than before the infection, while the negative controls showed the opposite changes.

Also in the longitudinal study, after the infection, 59.3% of the COVID-19–positive patients showed deteriorated sperm concentration, 57.9% deteriorated total sperm count, 71.4% grade A sperm, 65.0% progressive motility, 69.3% total motility, and 75.0% sperm DFI, while the changes in negative controls were all less than 40%.

"Further research is needed to observe the long-term effect of COVID-19 on sperm quality or reproductive outcomes," the study authors wrote. "In addition, there may be a need to constantly monitor the SARS-CoV-2 infection and integrate screening and diagnosis of the disease in the management of male infertility."

Study: Return-to-school policies not linked to antibiotic prescribing for pink eye

News brief

Chris Dall, MA

Child with pink eye getting eye drops — FamVeld / iStock

A review of US commercial health insurance data found no association between topical antibiotic dispensation for acute infectious conjunctivitis (pink eye) and state-level return-to-school policies, researchers reported today in JAMA Pediatrics.

Using data from the 2021 MarketScan Commercial Claims and Encounters Database, researchers from Boston Children's Hospital, Harvard University, and University of California, San Francisco investigated topical antibiotic dispensing for children aged 3 to 17 who were diagnosed with acute infectious conjunctivitis. While guidelines do not recommend universal treatment for conjunctivitis, states have differing return-to-school policies, with some requiring medical evaluation and/or treatment with topical antibiotics and with others having no restrictions or no policy at all.

State policies have no impact

Among 26,901 children with acute infectious conjunctivitis (median age, 7 years; 48% female), topical antibiotics were dispensed to 69%. Antibiotics were more frequently prescribed to children who were preschool-aged, female, evaluated in the fall and winter seasons, and evaluated by non-eye specialists.

The state-level proportion of children treated with topical antibiotics ranged from 38% in Vermont to 83% in South Dakota. In a multivariable analysis, compared with no policy, neither the policy requiring evaluation, treatment, or symptom resolution (odds ratio [OR], 1.02; 95% confidence interval [CI], 0.87 to 1.20) nor the policy specifying no restrictions on return to school (OR, 1.02; 95% CI, 0.83 to 1.25) was associated with topical antibiotic treatment.

The study authors say that while topical antibiotic use may in some cases accelerate symptom resolution, antibiotic overuse remains a public health concern.

"These findings suggest that local policies, parental preferences, health care facility–level characteristics, or other unmeasured covariates may explain the observed variation in antibiotic treatment," the study authors wrote. "Further research is needed to identify factors underlying variation in antibiotic use and to promote uniform guidelines for practitioners and families."

Three more states report first measles cases of the year

News brief

Lisa Schnirring

Louisiana, Missouri, and Virginia have reported their first measles cases of 2025, according to announcements over the past few days from their respective health departments.

The Louisiana Department of Health, in an April 19 statement, confirmed an infection in an adult in the region that includes New Orleans. The patient is unvaccinated, likely contracted the virus during international travel, and is isolating until no longer infectious.

The state reported three similar cases in 2024, all in the New Orleans area.

Two cases involved children

In Missouri, the health department on April 18 reported a confirmed measles case in a visitor of Taney County in the southwestern part of the state near Branson. The patient is a child whose vaccination status hasn’t been verified and is thought to have been exposed during international travel.

The Missouri Department of Health and Senior Services (DHSS) said the patient was diagnosed soon after arriving in Taney County and that exposure to others is thought to be limited.

Elsewhere, the Virginia Department of Health on April 19 announced the state’s first measles case of the year, which involves a child younger than 4 years old in the northwestern part of the state who recently traveled internationally. Officials reported potential exposures at medical facilities, one in Woodbridge and the other in Fredericksburg.

Though the United States is experiencing multiple outbreaks, including a large one centered in West Texas, states continue to report a small but steady stream of cases linked to international travel, part of a global rise in measles activity.