Probe of first US Omicron cluster hints at shorter incubation period
The incubation period for the Omicron variant may be shorter than for Delta and the original SARS-CoV-2 virus, Nebraska researchers reported yesterday, based on an analysis of the first known Omicron cluster in the United States. The team reported its findings yesterday in an early online edition of Morbidity and Mortality Weekly Report (MMWR).
The cluster involves six COVID-19 cases from one household in Nebraska that was reported to Nebraska health officials 2 days before the nation's first Omicron case was confirmed in a California patient. Genomic sequencing in Nebraska identified the same Omicron genotype for each cluster patient.
The index patient was unvaccinated and had unmasked contact with a masked sick person on Nov 20 during a conference in Nigeria that had international attendees, including from multiple African countries. He tested negative and was asymptomatic during return-flight protocols, but began having symptoms the day after he arrived home. A rapid test conducted 2 days later at a local medical center was positive for COVID-19.
All six household members began having symptoms within 2 days of when the index patient started feeling sick. He and four other household members had a history of prior COVID-19 infection. One household member was fully vaccinated and had had an earlier infection.
Observations include a shorter incubation and milder symptoms. The median incubation period in the cluster patients was 3 days, compared to about 4 days for Delta, and 5 or more days for earlier SARS-CoV-2 viruses.
Dec 28 MMWR report
Weight loss surgery linked to better COVID-19 outcomes among obese patients
Substantial weight loss achieved through surgery was associated with improved outcomes of COVID-19 infections, researchers with the Cleveland Clinic reported today in JAMA Surgery.
To investigate the association between a successful weight loss intervention and improved risk and severity of COVID infection among patients with obesity, which is an established risk factor for severe COVID-19 outcomes, the researchers analyzed data on a cohort of patients who underwent weight loss surgery (gastric bypass or sleeve gastrectomy) at the Cleveland Clinic from 2004 through 2017. Patients in the surgical group were matched 1:3 to patients who did not undergo surgery for their obesity (the control group). The primary outcomes were a positive SARS-CoV-2 test result, hospitalization, need for supplemental oxygen, and severe COVID-19.
A total of 20,212 patients were enrolled, 77.6% female, with a median age of 46 years and a median body mass index of 45. Among the 11,809 patients available on March 1, 2020, for an assessment of COVID-19-related outcomes, 784 (206 in the surgical group and 578 in the control group) had a positive SARS-CoV-2 test result. The rate of positive SARS-CoV-2 test results were similar in the surgical and control groups (9.1% vs 8.7%). But undergoing weight loss surgery was associated with a 49% lower risk of hospitalization (adjusted hazard ratio [HR], 0.51; 95% confidence interval [CI], 0.35 to 0.76; P < .001), a 63% lower risk of need for supplemental oxygen (adjusted HR, 0.37; 95% CI, 0.23 to 0.61; P < .001), and a 60% lower risk of severe COVID-19 infection (adjusted HR, 0.40; 95% CI, 0.18-0.86; P = .02).
Although the study was observational and the exact underlying mechanisms remain uncertain, the study authors say the findings suggest people who'd had weight loss surgery were generally healthier at the time of their infection and were likely physically and physiologically better equipped to cope with the infection. But they also note that it should not be misinterpreted as demonstrating the superiority of weight loss surgery over non-surgical treatment of obesity, as the control group was not composed exclusively of patients pursuing other means of weight loss.
"The findings of this study suggest that obesity can be a modifiable risk factor for the severity of COVID-19 infection," they write.
Dec 29 JAMA Surg study
Study finds high prevalence of antibiotic use in Latin American hospitals
A point prevalence survey (PPS) conducted in hospitals in five Latin American countries showed that more than half of hospitalized patients received an antibiotic on the day of the survey, researchers reported this week in the Journal of Antimicrobial Chemotherapy.
The Latin-PPS, conducted in hospitals in Cuba, Paraguay, El Salvador, Mexico, and Peru from December 2018 through August 2019, included a total of 5,444 patients at 33 hospitals. Researchers used an adaptation of the World Health Organization (WHO) model for conducting a PPS on antibiotic use, collecting data on patients, antibiotics, and indications. Hospital wards were divided into medical (MED), surgical (SUR), intensive care units (ICUs), gynecology and obstetrics (GO), high-risk (HR), and mixed wards (MIX).
Of the 5,444 patients, 54.6% received at least one antibiotic, with variations within and between hospitals. The lowest antibiotic use was found in Cuban hospitals (47.6%) and the highest in Paraguayan hospitals (81.1%). Antibiotics were most frequently used in ICUs (67.2%), followed by SUR (64.5%) and MED wards (54.2%). Overall, community-acquired infections (CAIs) were the most frequent reason for prescribing antibiotics (51.2%), followed by healthcare-associated infections (HAIs, 22.9%), surgical prophylaxis (11.1%), and medical prophylaxis (4.0%).
Main diagnoses were similar among countries, with pneumonia being the most frequent (26.4%), followed by urinary tract infections (15.3%), non-surgical infections involving skin or soft tissue (12.7%), and intra-abdominal infections, excluding gastrointestinal infections (11.7%) and clinical sepsis (7%).
Adherence to prescribing guidelines was observed in 68.6% of cases (72.8% for CAIs, 72.4% for HAIs, and 44.3% for prophylaxis). Third-generation cephalosporins were the most frequently used antibiotic (26.8%), followed by carbapenems (10.3%) and fluoroquinolones (8%). Targeted treatments were achieved in 17.3% of cases.
The study authors note the prevalence of antibiotic use observed in the PPS is significantly higher than previously found in Latin America by the WHO in its 2015 Global-PPS (31%), and higher than has been observed in Europe (28%) and the United States (46%).
"There is an urgent need to promote and strengthen the antimicrobial stewardship programs in Latin America," they wrote.
Dec 27 J Antimicrob Chemother abstract
PAHO: prepare for battle against both flu and COVID-19
Given increases in H3N2 influenza activity in the Americas, especially in Northern Hemisphere countries, the Pan American Health Organization (PAHO) yesterday in an epidemiological update urged countries to take steps to prepare for a battle against cocirculating flu and COVID-19.
Over the past 4 weeks, flu levels have been rising in the Northern Hemisphere, as well as in the Andean subregion and the Southern Cone, especially Brazil. PAHO said factors include the onset of the Northern Hemisphere's flu season, increased population mobility, and relaxed COVID-19 measures.
PAHO urged countries to take steps to ensure good clinical management of both conditions, including procuring antiviral supplies, ensuring strict infection prevention measures in health settings, and boosting vaccination to prevent severe illness and deaths.
Dec 28 PAHO epidemiological update