Some countries in the Southern Hemisphere, currently in their summer season, are experiencing higher-than-expected levels of respiratory disease activity for this time of year due to COVID-19, the Pan American Health Organization (PAHO) said yesterday in an epidemiologic update.

Activity has been rising since August in many Americas subregions, including the North American, Andean, Brazilian, and Southern Cone, PAHO said. In North America, elevated levels of COVID, flu, and respiratory syncytial virus (RSV) levels continue.

Meanwhile, in the Andean region, COVID levels are moderate, with levels rising over the past 4 weeks. Bolivia and Ecuador are reporting high activity. In the Southern Cone, COVID activity has ranged from medium to very high over the past 4 weeks, with Chile reporting very high activity, Brazil with high activity, Argentina at the intermediate level, and Paraguay at the moderate level.

Flu also increasing

PAHO also noted that flu has slightly increased from a low level in the Andean subregion and had remained at the epidemic level in Ecuador. In the Southern Cone, Chile has experienced flu above the threshold level over the past 4 weeks.

PAHO urged countries in the region to strengthen their respiratory virus surveillance and prepare healthcare systems for possible rises in inpatient visits and hospitalizations.

The alert comes amid expanding dominance of the JN.1 Omicron SARS-CoV-2 variant, which is thought to partially evade immunity from earlier infection, vaccination, or both. And though there's no evidence that JN.1 infections are more severe, some experts have warned that a surge in cases could put pressure on health systems.

Rising flu activity in temperate Northern Hemisphere countries, especially in North America, Europe, and Central Asia, has led to a rise in global flu detections, the World Health Organization (WHO) said yesterday in an update that covers roughly the middle 2 weeks of December.

In North America, flu is high or very high across most of the United States, and Canada's activity is at expected levels for this time of year. For the week ending December 31, activity in Europe and Central Asia was up sharply over the epidemic threshold. For example, Russia reported very high flu activity, with Greece and Luxembourg reporting high levels.

East Asia's activity remained elevated, mainly due to activity in China and South Korea. Elsewhere, Algeria reported an increase in flu detections, as did Lebanon. In Oceania, Australia's flu activity remained low overall, but with small increases reported in some states. And in temperate South America, flu was above the seasonal threshold in Chile.

Globally, of respiratory samples that were positive for flu at national flu labs in the middle of December, 86.6% were influenza A, and, of subtyped samples, 72.7% were the H3N2 strain.

A randomized clinical trial conducted in Spain found that linezolid is not an effective treatment for patients with early syphilis, researchers reported yesterday in The Lancet Infectious Diseases.

The multicenter non-inferiority trial aimed to investigate the efficacy of linezolid for treating early syphilis compared with the standard treatment, benzathine penicillin G (BPG), which has been hampered by drug shortages, scant randomized trial data, and the absence of a penicillin alternative for patients with penicillin allergy. Linezolid has shown activity against the bacterium that causes syphilis, Treponema pallidum, in vitro and in rabbits.

To compare the treatments, investigators recruited participants with serologic or molecular confirmation of syphilis and randomized them 1:1 to receive either oral linezolid for 5 days or a single intramuscular dose of BPG. The primary end point was treatment response (a composite end point that included clinical response, serologic response, and absence of relapse). The non-inferiority margin was –10%.

Trial terminated early

Fifty-nine patients were included in the trial, with 29 assigned to the linezolid arm and 30 to the BPG arm. In the per-protocol population, after 48 weeks of follow-up, 19 of 27 (70%) participants in the linezolid arm had responded to treatment, compared with 28 of 28 (100%) of patients in the BPG arm. The treatment difference (–29.6; 95% confidence interval [CI], –50.5 to –8.8) did not meet the non-inferiority criterion.

"Hence, the use of linezolid 600 mg per day for 5 days is not recommended to treat patients with early syphilis," the study authors wrote.

The number of drug-related adverse events was similar in both groups (17% vs 17%), with no serious events reported during follow-up. Enrollment in the trial was halted early for futility.

The authors suggest the dosing used might have been too low or the duration of the treatment might have been too short for effectively treating syphilis, and they say it's possible the efficacy of linezolid could increase with an extended regimen.

In an accompanying commentary, experts at the University of Southern California say the shortages of BPG underline the urgency of finding alternative treatment options.

The Novo Nordisk Foundation today announced a $25 million, 3-year grant to CARB-X (the Combating Antibiotic-Resistant Bacteria Biopharmaceutical Accelerator) to support early-stage development of products to treat, prevent, and diagnose antibiotic-resistant infections.

The funding will help CARB-X continue the work it's been doing since 2016, when the public-private partnership was launched at Boston University. CARB-X identifies promising products—including antibiotics, vaccines, and diagnostic tools—targeting some of the most difficult-to-treat bacterial pathogens and provides funding to help move those products from basic research through phase 1 clinical trials. Since 2016, CARB-X has funded 93 projects in 12 countries, 19 of which have advanced into or completed clinical trials.

"Like CARB-X, the Novo Nordisk Foundation is committed to driving innovation in the fight against drug-resistant infections," Peter Lawaetz Andersen, Senior Vice President in Infectious Disease at the Foundation, said in a press release. "By partnering, we can help ensure that the best research gets translated into effective, scalable and affordable medical interventions that can help end this growing pandemic."

CARB-X Executive Director Kevin Outterson, JD, called the Novo Nordisk Foundation a "key ally" in its mission.

"This new funding is a testament to our shared commitment to supporting the pioneering efforts of antibacterial product developers, mainly university spinoffs and small biotech companies, in advancing much-needed innovation to prevent, diagnose, and treat the most dangerous drug-resistant bacterial infections," he said.

By partnering, we can help ensure that the best research gets translated into effective, scalable and affordable medical interventions that can help end this growing pandemic.

• Cameroon's health ministry today announced that its malaria vaccine campaign will launch on January 22, with free doses available to children at public and private clinics across 42 health districts, Xinhua reported today, based on a health ministry statement. In November, Cameroon said it would receive 331,200 doses of RTS,S, which is produced by GSK. The launch of the malaria vaccine in Cameroon is part of a broader rollout in Africa, where a few countries such as Malawi have been part of pilot programs. Africa has been hardest hit by malaria.
• Two more measles cases have been confirmed in Philadelphia's measles outbreak, raising the total to eight, the Philadelphia Department of Public Health said yesterday in an update. Seven patients are Philadelphia residents, and one is from outside the city. The outbreak began in December, with the virus spreading to two hospital patients and to children in a daycare. The health department also expanded its list of potential exposure sites, most of which are clinics or hospitals.
• More countries in Europe continue to report more highly pathogenic H5N1 avian flu outbreaks in wild birds and poultry, according to the latest notifications from the World Organization for Animal Health (WOAH). Sweden reported its first recurrence in poultry since June 2023, with the virus striking a broiler breeding farm near Sjobo in Skane County in the south. Also, Finland reported the virus in a goshawk found dead in Helsinki.