News Scan for Sep 22, 2021

News brief

Fluoroquinolones tied to increased risk of acute liver injuries

A nationwide cohort study in Sweden found a twofold increased risk of acute liver injuries (ALIs) associated with oral fluoroquinolones in the first 2 months after starting treatment, researchers reported this week in Clinical Infectious Diseases.

Using individual data from national healthcare and drug registries, researchers investigated the risk of ALI in Swedish adults ages 40 to 85 who were prescribed oral fluoroquinolones or amoxicillin from July 2006 to January 2014. To reduce the influence of confounding from baseline health factors, they used propensity score matching. The main analysis and follow-up interval was 1 to 60 days after filling a prescription.

Comparing 419,930 courses of oral fluoroquinolones and amoxicillin, respectively, over the study period, the researchers found 18 events in the oral fluoroquinolones group and 8 in the amoxicillin group. There was an increased risk of ALI associated with oral fluoroquinolones, with a hazard ratio (HR) of 2.32 (95% confidence interval [CI], 1.01 to 5.35). The adjusted absolute risk difference for use of fluoroquinolones compared with amoxicillin in the 60-day period was 4.94 (95% CI, 0.04 to 16.3) per 1 million episodes. There were no observed differences in any subgroups.

The results align with previous studies that have found an increased risk of ALI associated with oral fluoroquinolones, which are one of the most widely used antibiotic classes and have also been linked with tendon injuries and heart-rhythm issues. While the absolute risk of ALI is low, the study authors note that the extensive use of fluoroquinolones needs to be considered.

"Naturally, the low absolute risk needs to be taken into consideration when weighing cost vs. benefit of initiating treatment with these drugs," they wrote. "Nevertheless, the scope of the worldwide and extensive use of fluoroquinolones is substantial and also has to be factored into the overall picture."
Sep 19 Clin Infect Dis abstract

H5N6 avian flu case hospitalizes man in China's Guangdong province

China today reported its 20th human H5N6 avian influenza case of the year, a 53-year-old man from Dongguan in Guangdong Province, according to a provincial health commission statement translated and posted by Avian Flu Diary (AFD), an infectious disease news blog.

The reported didn't detail when the patient's symptoms began or how he may have contracted the virus, but said the man is currently hospitalized.

China has now reported 44 cases since 2014, nearly half of them related to an uptick in cases this year. H5N6 is known to circulate in poultry, mostly in Asia. However, human cases—which are often severe or fatal—have been reported only in China and Laos.
Sep 22 AFD post

African swine fever strikes second Caribbean country

Haiti recently reported an African swine fever (AFS) case in a pig, the second country in the Americas to report the disease in the past 2 months, according the US Department of Agriculture's (USDA's) Animal and Plant Health Inspection Service (APHIS). AFS doesn't infect humans but can destabilize pig markets.

APHIS said the samples were collected form a pig in a province that borders the Dominican Republic, which in July reported the first appearance of the virus in nearly 40 years. Though unfortunate, the development isn't surprising, given the recent events in the Dominican Republic, officials said.

APHIS has several safeguards for preventing the spread of the disease into the United States, including rules against importing pork products from the two countries. Last month, officials established a protection zone in Puerto Rico and the US Virgin Islands and an order that suspends the movement of all swine products from the two locations into the US mainland.

A report from the World Organization for Animal Health (OIE) said Haiti's last appearance of ASF was in 1984 and that the latest detection occurred in backyard animals in the city of Anse-à-Pitres in the far southeast corner of the country. The virus killed 234 of 2,500 pigs.
Sep 21 USDA APHIS statement
Aug 4 CIDRAP News scan
Sep 18 OIE report

COVID-19 Scan for Sep 22, 2021

News brief

Overall COVID risk for air travel is low, study says

Overall SARS-CoV-2 attack rates in airplane flights under 4 hours were less than 1%, according to a study of 177 flights departing from Wuhan, China, in January 2020. The results, published yesterday in Clinical Infectious Diseases, also indicated that people in the same row as an index case had the highest risk of infection.

Among 5,797 passengers, 175 were index patients and led to an upward estimate of 34 secondary cases. Estimates of attack rates had an upper bound of 0.60% and a lower bound of 0.3% (95% confidence intervals [CIs], 0.4% to 0.8% and 0.2% to 0.5%, respectively). Each index case infected 0.2 passengers in the upper-bound estimate and 0.1 passengers in the lower-bound estimate.

People sitting immediately next to the index patient had a much higher attack rate of 9.2% (95% CI, 5.7% to 14.4%), creating a relative risk of 27.8 (95% CI, 14.4 to 53.7) compared with other seats in the upper-bound estimation. Comparing overall window, middle, and aisle seats, the middle seat had the highest attack rate at 0.8%. Upper-bound attack rates went from 0.7% to 1.2% when the traveling time increased from 2.0 to 3.3 hours.

The study took place prior to COVID-19 mitigations, such as masks or physical distancing on planes, and the researchers did not have knowledge about relationships among travelers. However, they defined an index case as someone who was confirmed with COVID-19 post-travel, had symptom onset within 14 days before traveling or within 2 days after travel, and had the earliest date of symptom onset among passengers within 3 rows. Close contacts were passengers within 3 rows of the index case.

For upper-bound risks, the researchers assumed no relationship or contact between passengers before or after the journey, but for the lower-bound risk, passengers seated immediately next to the index patient were excluded if they had the same departure and destination.
Sep 21 Clin Infect Dis study

Dexamethasone may be less effective in LMICs, study says

Dexamethasone, which is used to treat critically ill COVID-19 patients, may be less effective in lower- and middle-income countries (LMICs) compared with high-income countries, according to a modeling study published yesterday in Clinical Infectious Diseases.

Accounting for healthcare capacities, epidemic trajectories, and drug efficacy without the help of supportive care, the researchers calculated that dexamethasone would prevent 22% of deaths in high-income countries and 8% of deaths in LMICs if COVID-19 epidemic mitigations were occurring. If the local epidemic was being poorly mitigated, then dexamethasone would prevent 18% of deaths in high-income countries and 5% in low-income countries.

Increasing the use of therapeutics that prevent COVID-19 or that stop illness from becoming severe could help the effectiveness of dexamethasone and other COVID-19 treatments, according to the researchers. If healthcare systems are stretched to capacity, however, fewer individuals who are hospitalized receive dexamethasone, and fewer hospitalized people receive supportive healthcare, which would maximize dexamethasone's effect.

"Our results show that effect sizes for therapeutics estimated in clinical trials will not necessarily provide a guide to their 'real-world' impact on COVID-19 disease burden as 'real-world' impact also crucially depends on prevailing healthcare constraints, the trajectory of the epidemic and the extent to which benefits persist in the absence of supportive care," the researchers conclude.
Sep 21 Clin Infect Dis study