The results of a phase 4 randomized controlled trial indicate shortened regimens of preventive tuberculosis (TB) therapy are safe and effective options for preventing active TB infections, US and Brazilian researchers reported yesterday in PLOS Medicine.

The trial, conducted in Rio de Janeiro and Manaus, assigned 500 people age 15 and older without HIV who had household or occupational exposure to individuals with confirmed TB infection to receive either one or three months of isoniazid and rifapentine (HP; 1HP or 3HP). 

Both regimens have been found in previous trials to be effective at preventing active TB infection and are significantly shorter than the standard regimen (six to nine months of isoniazid), which has been the mainstay of TB preventive therapy (TPT) for decades but has had "abysmal" uptake and poor completion rates. But some data gaps remain.

"The availability of two innovative short-course TPT regimens offers a transformative opportunity for global tuberculosis control and achieving the End TB targets," the study authors wrote. "However, the safety of the 1HP regimen in people without HIV infection has not been thoroughly evaluated, and the relative acceptability of 1HP versus 3HP is unknown."

High completion rates in both groups

The primary outcomes of the trial were successful completion of more than 90% of medication in the regimens and safety.

Both treatment regimens had high completion rates—89.6% in 1HP recipients and 84.1% in the 3HP group. Adverse reactions were mostly mild or moderate, with targeted safety events or treatment discontinuation because of side effects occurring in 16.1% of patients in the 1HP group and 10.4% in the 3HP arm. Neither regimen was considered superior to the other.

The study authors say the results provide clinicians, public health officials, and patients with the data needed to make informed choices about which regimens to use and could help Brazil and other high TB-burden countries achieve TB control. 

“Preventing TB with short courses of well-tolerated medicines ensures that millions more people around the world can be protected from the devastating consequences of TB disease,” coauthor Marcelo Cordeiro-Santos, MD, PhD, said in a journal press release.

Mexican health officials are reporting six new human cases of myiasis caused by New World screwworm (NWS) over the past week.

In an epidemiologic surveillance report released earlier this week, Mexico's Ministry of Health said 141 cases have now been reported from eight Mexican states, up from 135 the previous week. Most of the cases (103) of the parasitic infection, which is carried by the Cochliomyia hominivorax fly, have been in Chiapas. Mexico has also reported more than 600 cases in animals.

The infection occurs when the flies deposit eggs into the open wounds and mucous membranes of warm-blooded animals; the eggs develop into larvae that burrow into the flesh, causing severe damage. Cases can be fatal if left untreated. 

Sterile fly dispersal facility opens

While human cases are rare, US officials have been concerned about the northward spread of NWS from Central America and the potential threat to the US cattle industry. 

In May 2025, the US Department of Agriculture (USDA) suspended livestock imports at the southern border because of an increase in cattle infections in Mexico. The following month, USDA Secretary Brooke Rollins announced the agency would launch a sterile fly dispersal facility in Edinburg, Texas, near the Mexican border. 

Releasing sterile male flies outside of affected areas ensure that female NWS flies, which only mate once, will encounter only sterile partners and not be able to reproduce.

The USDA announced the completion of the facility earlier this week.

"This new facility is a monumental achievement for our domestic preparedness efforts, but we are also diligently working to stop the spread of screwworm in Mexico, conduct extensive trapping and surveillance along the border, increase U.S. response capacity, and encourage innovative solutions," Rollins said in a press release.

Hong Kong’s Centre for Health Protection (CHP) yesterday reported two new H9N2 avian flu cases with symptom onsets in December and January, and an H10N3 patient whose illness began on December 29. 

The H9N2 cases include a 2-year-old boy from Hunan province who got sick on December 29, and a 73-year-old woman from Guangdong province whose symptoms began in January 17. The influenza A(H10N3) case occurred in a 34-year-old man also from Guangdong province. 

None of the case-patient died from their infection, but no details were given on where they contracted the virus, symptoms, or recovery timeline. 

Inconsistencies with WHO data

CHP’s avian flu postings and reports have been inconsistent with updates from the World Health Organization (WHO), which reported three H9N2 cases from January 9 to 15, all of whom had symptom onset in November and December of last year. According to the WHO, the last known case of H10N3 was in April 2025, and the most recent case reported by the CHP would be the seventh ever reported. 

Per the CHP, there have been 20 H9N2 cases reported in China in the past 6 months.

In 2025, there were 29 H9N2 cases reported from mainland China. In 2024, the country reported 11 total cases.