Mpox vaccine efficacy estimated at 80%

News brief

A new study of the Jynneos two-dose mpox vaccine shows it was 80% effective in preventing infection among recipients in the United Kingdom in 2023, according to research published yesterday in Emerging Infectious Diseases. Of note, no one who was vaccinated was hospitalized with the viral disease.

By 2023, the peak of mpox activity primarily among men who have sex with men (MSM) in the United Kingdom had passed, with only 137 cases reported during the year. Cases were recorded through the UK Health Security Agency, as mpox is a notifiable disease in the country.

To examine efficacy of the vaccine against infection mostly among MSM, the authors estimated the proportion of MSM vaccinated by matching each case to the one- and two-dose coverage at the time, 2 weeks before the men contracting mpox, then averaging the matched coverage across cases.

One-dose protection 84%

Of the 137 case-patients, 47% reported no travel outside the United Kingdom in the 21 days before symptom onset, indicating likely acquisition in the United Kingdom. Most case-patients identified as MSM (78%), the authors said, though another 21 were adult men without recorded information about sexual orientation and no travel to mpox-endemic countries. Nine case-patients were excluded from the final analysis, 8 of whom linked to an mpox-endemic country.

Vaccine efficacy (VE) of one dose of Jynneos was estimated at 84% (95% confidence interval [CI], 74% to 91%) and the VE after dose two was 80% (95% CI, 69% to 83%).

Our finding is corroborated by a global case series that found illness among vaccinated persons to be less severe.

"Among known vaccinated case-patients in 2023, none were hospitalized. Of 11 (9%) persons who required hospital treatment for mpox, 9 were unvaccinated and vaccination status was unknown for 2," the authors said. "Our finding is corroborated by a global case series that found illness among vaccinated persons to be less severe."

CDC snapshot details Oropouche virus infection in 21 travelers to Cuba

News brief

Lisa Schnirring

The Centers for Disease Control and Prevention (CDC) and state partners from Florida and New York yesterday reported their clinical findings on 21 imported Oropouche virus cases reported this summer. The team's early online report appears in Morbidity and Mortality Weekly Report (MMWR).

The disease, spread by biting midges and perhaps some mosquito species, has been spreading beyond endemic areas of South America since the end of 2023, fueling outbreaks and reports of severe fetal outcomes following infection during pregnancy. Earlier this month, the CDC issued Oropouche virus alerts for clinicians and travelers.

Of the 21 cases confirmed in the United States, 20 were in Florida and 1 in New York state. All of the patients had traveled to Cuba. Three people were hospitalized, but no deaths were reported. Similar imported cases have been reported in European travelers.

Cases continue to rise in Florida, which has now reported 30 imported Oropouche cases, according to the latest vectorborne illness report from the Florida Department of Health.

Relapsing symptoms a unique Oropouche feature

Most patients had a self-limiting febrile illness with headache and muscle aches, a clinical picture that is similar to other arboviral disease, including dengue, Zika, and chikungunya. Some Oropouche patients reported gastrointestinal symptoms.

At least three patients, however, sought care when they had relapsing symptoms, which the authors said is a unique feature of Oropouche virus infection.

The CDC said the risk for sustained local transmission is low, and it urged people who have been in Oropouche-affected areas, including those experiencing symptoms, to take steps to avoid insect bites for 3 weeks after returning home.

Studies are under way to see of US biting midge and mosquito species are capable of carrying the virus, and the CDC said it working with the Pan American Health Organization and other partners to learn more about infection risks during pregnancy.

Novel scoring tool linked to reduced urinary antibiotic prescribing

News brief

Chris Dall, MA

Implementation of a novel scoring tool for urine culturing was associated with a more than 30% reduction in urinary antibiotic prescribing at a rehabilitation facility for long-term care (LTC) patients in Canada, researchers reported today in Infection Control & Hospital Epidemiology.

The aptly named BLADDER score was developed by clinicians at a 134-bed complex-continuing-care and rehabilitation facility in Ontario to promote more appropriate urine culturing in non-catheterized patients with presumed urinary tract infections (UTIs). Each of the letters in the score represents a possible symptom representative of UTI (B, blood in urine; L, loss of urinary control or incontinence; A, abdominal or flank pain; D, dysuria or pain on urination; E, elevated temperature or fever; R, repeated urination or frequency), with 1 point given for each letter in the algorithm; a score below 2 suggests careful monitoring of patient symptoms rather than a urine culture.

To evaluate the impact of the scoring tool, researchers compared urine culturing, urinary antibiotic use and length of stay (LOS), acute-care transfers, and mortality 18 months before and 16 months after the intervention.

32% decline in urinary antibiotic prescribing

Before the intervention, the mean rate of urine culturing was 12.47 cultures per 1,000 patient-days; after the intervention, the rate was 7.92 cultures per 1,000 patient-days (incidence rate ratio (IRR), 0.87; 95% confidence interval [CI], 0.67 to 1.12). Although the decline in urine culturing was not considered statistically significant, urinary antibiotic use declined significantly after the intervention, from a mean of 40.55 defined daily doses (DDD) per 1,000 patient-days before to 25.96 DDD per 1,000 patient-days after the intervention (IRR, 0.68; 95% CI, 0.59 to 0.79). There was no change in mean patient LOS, acute-care transfers, or mortality.

"The implementation of a scoring tool may be a useful adjunct to further explore in addition to other diagnostic stewardship strategies in hospitalized and LTC patients," the study authors wrote. "Such a tool may be particularly useful as part of electronic health records as a trigger to consider more judicious culturing practices."