Stewardship / Resistance Scan for Aug 23, 2022

News brief

Trial finds no impact on trachoma from mass azithromycin distribution

A randomized clinical trial in Niger found that mass distribution of azithromycin to preschool-aged children was no more effective at reducing incidence of trachoma than placebo, researchers reported today in JAMA Network Open.

The cluster-randomized trial, conducted by investigators with the Macrolides Oraux pout Réduire les Décés Avec un Oeil sur la Resistance (MORDOR)-Niger Study Group, assessed the effects of biannual mass azithromycin distribution to children ages 1 to 59 months in 30 villages in a region of Niger thought to have hypoendemic trachoma. The World Health Organization (WHO) recommends mass distribution of azithromycin for districts with trachoma, the world's leading infectious cause of blindness, but concerns that mass antibiotic administration to entire communities could promote antibiotic resistance has led researchers to ask whether targeted distribution might be a better strategy.

A total of 4,756 children in 30 communities were included, with 1,695 children enrolled in 15 azithromycin communities and 3,031 in 15 placebo communities. Enrolled children received a single dose of oral azithromycin or oral placebo every 6 months over 24 months. The primary outcome of the trial was the incidence of trachomatous inflammation-follicular (TF).

The mean prevalence of TF at baseline was 1.9% (95% confidence interval [CI], 0.5% to 3.5%) in the azithromycin group and 0.9% (95% CI, 0 to 1.9%) in the placebo group. At 24 months, TF prevalence was 0.2% (95% CI, 0 to 0.5%) in the azithromycin group and 0.8% (95% CI, 0.2% to 1.6%) in the placebo group. The lower incidence of TF in the azithromycin group was not considered statistically significant (incidence rate ratio adjusted for baseline: 0.18 [95% CI, 0.01 to 1.20]).

The study authors say that the low baseline prevalence of trachoma in the communities makes it difficult to determine whether targeted mass distribution of azithromycin to preschool-aged children could be an effective strategy for trachoma elimination. It also suggests trachoma may have been eliminated as a public health problem in those communities.

"It remains unclear whether azithromycin distributions to preschool-aged children would be effective in other areas with hypoendemic trachoma that have slightly more infection than those assessed in the present study," they wrote.
Aug 23 JAMA Netw Open study

Multidrug-resistant TB treatment more effective than thought

A systematic review and meta-analysis of studies from countries in Central and West Africa found higher-than-expected treatment success rates for multidrug-resistant and rifampicin-resistant tuberculosis (MDR/RR-TB), researchers reported yesterday in the International Journal of Infectious Diseases.

The analysis of 14 studies from 14 countries in the two regions, published from 2005 through 2020 and including 4,268 people, found the overall treatment success was 74.6% (95% confidence interval [CI], 65% to 82.2%), with a pooled success rate of 80.8% (95% CI, 56% to 93.3%) for the Central African subgroup and 69.3% for the West African subgroup (95% CI, 56.3% to 79.7%). The estimated proportion of successfully treated MDR/RR-TB patients was significantly higher than the WHO's estimate of 59% and reaches the WHO's 2015 target of 75% treatment success for MDR-TB.

The findings are surprising because the studies were conducted while countries in the region were using the standard MDR-TB regimen, which lasts 18 to 24 months and includes injectable drugs. Poor adherence to that regimen has been associated with low treatment success rates. The authors note the findings may be explained by early introduction of a 9- to 11-month regimen in many of the included countries, along with the absence of data from 12 countries in the region.

"Whether this reflects the true rate of treatment success or whether the rate is skewed due to underreporting remains unknown," they wrote.

In 2022, the WHO endorsed a 6-month all-oral regimen for MDR-TB that experts hope will lead to even better treatment outcomes.
Aug 22 Int J Infect Dis study

News Scan for Aug 23, 2022

News brief

Long COVID relatively rare in children and teens, study suggests

A study published yesterday in JAMA Pediatrics suggests that long COVID is uncommon in children and teens and that risk factors include severe SARS-CoV-2 infection, younger age, and complex underlying chronic diseases.

The US Centers for Disease Control and Prevention defines long COVID as continuous, relapsing, or new symptoms or conditions persisting at least 1 month after the initial infection.

University of Colorado researchers evaluated the PEDSnet electronic health records (EHRs) of 659,286 patients aged 0 to 20 years tested for COVID-19 at one of nine US hospitals from Mar 1, 2020, to Oct 31, 2021. Average follow-up time was 4.65 months. The average patient age was 8.1 years, 52.8% were male, and 9.1% tested positive for COVID-19. The hospitals were located in Pennsylvania, Ohio, Colorado, Illinois, Delaware, Florida, Washington state, and California.

COVID-19 patients had elevated rates of myocarditis (inflammation of the heart muscle; adjusted hazard ratio [aHR], 3.10), acute respiratory distress syndrome (aHR, 2.96), muscle inflammation (aHR, 2.59), other or ill-defined heart disease (aHR, 1.47), fluid or electrolyte disturbances (aHR, 1.45), treatment for mental illness (aHR, 1.62), and anxiety (aHR, 1.29).

Other common conditions included changes in smell and taste (aHR, 1.96), hair loss (aHR, 1.58), chest pain (aHR, 1.52), abnormal liver enzymes (aHR, 1.50), rashes (aHR, 1.26), fatigue and malaise (aHR, 1.24), fever and chills (aHR, 1.22), cardiorespiratory signs and symptoms (aHR, 1.20), and diarrhea (aHR, 1.18).

A total of 41.9% of COVID-positive patients reported at least one systemic or syndromic long-COVID sign or symptom or use of an over-the-counter cough and cold medication, compared with 38.2% among test-negative patients (difference, 3.7 percentage points, or a 9.7% higher incidence).

Risk factors for long COVID included a stay in an intensive care unit during infection, age younger than 5 years, and complex chronic conditions.

"Our findings suggest that the burden and risk windows of PASC [postacute sequelae of SARS-CoV-2] may differ between children and adults," the researchers wrote. "Future studies, including long-term prospective studies, such as the National Institutes of Health RECOVER Initiative, are needed to fully elucidate PASC phenotypes."
Aug 22 JAMA Pediatr study

Olympics study shows wastewater sampling useful for COVID-19 outbreaks

As part of precautions taken during the 2020 Olympic and Paralympic Games in Tokyo, held in August and September of 2021, researchers tested wastewater in the sewage system of the Olympic Village daily, as well as athletes, for SARS-CoV-2. Today in JAMA Network Open, the authors show that the two practices complemented each other, and wastewater-based epidemiology (WBE) could predict uptick in COVID-19 cases.

The study compared clinically reported cases and viral loads in wastewater by using 360 samples collected from manholes in 7 areas of the Olympic Village to reported COVID-19 cases as given to the Tokyo 2020 Organizing Committee.

SARS-CoV-2 was found in 151 wastewater samples, including 98 during the Paralympics and 53 during the Olympics. The authors found a correlation between positive wastewater and clinical case positives, with positive sewage samples appearing 2 to 3 days before an uptick in clinically positive cases.

The Paralympics had more cases compared with the Olympics: 3.6 versus 3.2 confirmed cases per 1,000 participants.

"These findings suggest that WBE and clinical tests are complementary and that the testing strategy played a role in preventing COVID-19 clusters in the village. This study of one of the world’s largest mass gatherings provides novel evidence on the implementation and use of WBE in communities where all members undergo daily testing," the authors concluded.
Aug 22 JAMA Netw Open study

Global flu activity declining in most of world, except Southeast Asia

In an update that covers the last week of July and the first week of August, the World Health Organization (WHO) said yesterday that flu activity is declining in most parts of the world, except for in Southeast Asia.

Cambodia, Malaysia, Singapore, and Thailand are among the countries in Southeast Asia that are reporting rising flu activity, mostly involving H3N2. In East Asia, flu activity appears to have peaked in southern China, where H3N2 also predominated.

Meanwhile, in southern Asia, India reported a rise in H1N1 detections.

In the Southern Hemisphere, downward trends were reported from Australia and New Zealand, while levels remained stable in South Africa and declined in temperate parts of South America. In tropical African nations, flu activity declined. In North America and Europe, flu remained at inter-seasonal levels.

Globally, of respiratory samples that tested positive for flu during the latest reporting period, 96.2% were influenza A, and of the subtyped influenza A samples, 93.8% were H3N2.
Aug 22 WHO global flu update

Avian flu strikes more flocks in 3 states

Avian flu outbreaks continue over the summer months in US poultry flocks, with three more outbreaks reported, according to the latest updates from the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS).

One of the outbreaks struck a commercial broiler breeding farm housing 33,900 birds in Fresno County, California. Another affected backyard birds at a location in Washington's Kitsap County.

Also, the virus struck an animal rescue/rehabilitation facility in Henry County, Georgia, which has 90 birds. The Georgia Department of Agriculture said the outbreak is the second in Georgia and that the flock owners reported deaths in wild black vultures, as well illnesses in domestic birds. Samples were positive for highly pathogenic avian influenza.

Since the H5N1 outbreaks began in early February, the virus has led to the loss of 40.1 million birds across 39 states. Detections in wild birds have also continued over the summer in multiple US regions.
USDA APHIS poultry outbreak updates
Georgia Department of Agriculture update