Study challenges notion that Omicron COVID is always mild

News brief

Vaccinated or previously infected COVID-19 hospital patients had lower rates of severe illness and death than their unvaccinated, COVID-naive peers during both Omicron and Delta variant predominance. And while the unvaccinated had fewer poor outcomes during Omicron than in Delta, their risk was similar to that seen with previous SARS-CoV-2 strains, according to a study published today in Clinical Infectious Diseases.

Johns Hopkins University researchers studied the electronic medical records of COVID-19 patients at five hospitals in Maryland and Washington, DC, who had low oxygen levels, an abnormally rapid breathing rate or heart rate, or fever who had available viral whole-genome sequencing information from Sep 1, 2020, to May 7, 2022.

Of all patients, 3,369 were unvaccinated, and 1,230 were vaccinated or had previously tested positive for COVID-19. Vaccinated patients were older and had more underlying illnesses than the unvaccinated. Vaccination was considered the receipt of two doses of the Moderna or Pfizer/BioNTech COVID-19 mRNA vaccine or one dose of the Johnson & Johnson vaccine.

Vaccination, previous infection slashed risk

A total of 29% of unvaccinated patients and 22% of vaccinated or previously infected patients became severely ill (required advanced respiratory support) or died within 28 days. The relative risk (RR) of severe disease or death for unvaccinated patients during Delta, compared with previous strains, was 1.30. The RR of poor outcomes among unvaccinated Omicron (vs Delta) patients was 0.72, while it was 0.94 versus ancestral lineages.

Vaccinated or previously infected patients were at less than half the risk of severe illness or death amid both Omicron and Delta than their unvaccinated counterparts (adjusted hazard ratio, 0.40), but there was no significantly different outcome by variant.

The finding ... undercuts public perception that Omicron is a mild disease.

"The finding that unvaccinated individuals hospitalized with Omicron infections have similar risk of severe disease compared to cases prior to emergence of variants of concern undercuts public perception that Omicron is a mild disease," the study authors wrote. "Comparison of disease severity between Omicron and Delta alone overlooks the increased severity of Delta variant compared to prior lineages which were responsible for millions of deaths."

Report describes misdiagnoses of mpox

News brief

A new study from Israel describes 26 cases of misdiagnosed mpox. Of the 26, 6 patients (23%) who were given a diagnosis of bacterial tonsillitis, 6 (23%) primary syphilis, 5 (19.2%) oral or genital herpes, and 4 (15.3%) bacterial proctitis or anal abscess. The study was published in the International Journal of Infectious Diseases.

The study highlights how easily the disease was misdiagnosed during the initial months of a global outbreak that saw the virus spread in countries where it has never or rarely been detected. This is the first outbreak in many countries driven by sexual transmission among men who have sex with men (MSM) and not international travel.

The case-patients were all diagnosed between May and October of this year, and all were MSM. All patients said that during their first visit with a doctor, they were not asked about contact with an mpox patient. Of the 26 patients, 17 (65.3%) were on HIV prophylaxis, and 5 (19.2%) were HIV positive.

The average interval between missed and right diagnosis was 4.4 days.

"MPX infection may be easily overlooked and be confused with other diseases, mainly other STIs [sexually transmitted infections]. Due to the nature of its transmission, and its non-classical presentation of lesions concentrated in the anogenital areas in about 75% of the patients, it is most commonly confused with other STIs such as syphilis and genital herpes simplex infection" the authors said.

Avian flu outbreaks strike more US egg producers

News brief

Over the past week, federal officials reported more highly pathogenic avian flu outbreaks in 11 states, including three involving large layer farm operations. Also, the virus hit more turkey farms and backyard poultry flocks.

According to the latest updates from the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS), Colorado reported an outbreak at a layer farm in Weld County that houses 1.4 million birds. Similarly, South Dakota reported an outbreak at a layer farm in Moody County that has 1.3 million birds, and Washington reported an event at a layer farm in Franklin County has houses more than 1 million birds.

Meanwhile, other states reported new outbreaks on commercial turkey farms, including Indiana and Iowa. States that reported detections in other settings, including backyard flocks, include California, Montana, Oregon, Minnesota, Nebraska, and Tennessee.

So far, outbreaks involving the Eurasian H5N1 strain, first reported in US poultry in February, have led to the loss of a record 57.5 million birds from 47 states.

Canada, Mexico report high-path detections

In related developments, Canada reported several more highly pathogenic H5 avian flu detections in wild birds, including the H5N6 strain, which was found in a blue-winged teal near Winnipeg in Manitoba, according to a notification from the World Organization for Animal Health (WOAH). Meanwhile, tests identified H5N1 in wild birds from British Columbia, Alberta, Ontario, Quebec, Nova Scotia, and Newfoundland.

South of the US border, Mexico reported 20 more outbreaks in poultry, which hit farms across 7 states, leading to the loss of more than 4 million birds, according to a separate notice from the WOAH. Affected states are Chiapas, Nuevo Leon, Sonora, Mexico, Chihuahua, Jalisco, and Yucatan.

Price cut agreement could expand access to shorter treatment for resistant TB

News brief

An agreement announced today will help bring down the cost of two shorter treatment regimens for drug-resistant tuberculosis (DR-TB) patients, enabling greater access to the treatments.

The agreement, between TB Alliance, pharmaceutical company Viatris, and UK-based social enterprise MedAccess, will reduce the price of pretomanid, which is used in combination with bedaquiline, linezolid, and sometimes moxifloxacin as part of the BPal and BPaLM regimens, by 34%. The 6-month, all-oral regimens were recently recommended by the World Health Organization (WHO) for most patients with drug-resistant and multidrug-resistant (MDR)-TB.

Previous treatment regimens for DR-TB lasted as long as 20 months, involved injectable antibiotics with severe side effects, and were successful in roughly 50% of cases. In addition to being significantly shorter and easier on patients, the BPaL and BPaLM regimens have been effective at curing 89% to 91% of MDR-TB patients in clinical trials.

According to a press release from TB Alliance, which developed pretomanid, the agreement will enable 36,000 additional patients in more than 140 countries to be treated and will 31,000 adverse events. A volume guarantee to be provided by MedAccess t0 Viatris—one of the drug manufacturers that has received a non-exclusive license for pretomanid—will bring down the per-patient cost of the regimens to $500, and government and global procurers are expected to save more than $15 million.

"Coming on the heels of the WHO consolidated guidelines for DR-TB treatment, we hope this will be the game changer in ensuring access for people with DR-TB and reaching better treatment outcomes," Blessi Kumar, CEO of the Global Coalition of TB Advocates, said in the release.

According to the WHO's most recent global TB report, there were an estimated 450,000 cases of DR-TB in 2021.

"No medical innovation is complete until it’s able to reach every patient who needs it," said TB Alliance president and CEO Mel Spigelman, MD. "This new access partnership will accelerate the pace of progress and move us closer to a world in which no one dies of TB."

WHO issues draft action plan to boost infection prevention and control

News brief

The World Health Organization (WHO) last week released a draft of a new global strategy on infection prevention and control (IPC).

The draft strategy, developed in response to a World Health Assembly resolution, aims to address global gaps in IPC that have been exposed by the COVID-19 pandemic and the increasing burden of healthcare-associated infections (HAIs) and antimicrobial resistance (AMR). It focuses on IPC in any setting where healthcare is delivered and is based on the principles of clean and safe care as a human right.

"Having active IPC programmes in place is a proven effective approach to protect patients, health and care workers and visitors to health care facilities by preventing avoidable infections acquired during the provision of health services, including those caused by antimicrobial-resistant and epidemic- and pandemic-prone pathogens," the document states.

According to data provided to the WHO by 166 countries, approximately 1 in 10 countries do not have any IPC programs or operational plans, while 1 in 4 countries has a program that has not been fully implemented. Those gaps prompted a World Health Assembly resolution in May that called on Member States to improve IPC at the national, sub-national, and facility levels and asked WHO Director-General Tedros Adhanom Ghebreyesus, PhD, to develop a global action plan.

The three primary objectives of the draft strategy are to prevent infections in healthcare, to ensure that IPC programs are in place and implemented in accordance with the WHO's IPC core components, and to coordinate IPC activities with other areas and sectors. The country- and stakeholder-driven strategy calls for governments to demonstrate political commitment to IPC and provide funding for active IPC programs, to provide IPC education to healthcare workers across the entire health education system, to establish systems for regular data collection and HAI surveillance, and to promote IPC awareness.

WHO: Multiple factors drive expanding cholera outbreaks

News brief

In its latest snapshot of global cholera activity, the World Health Organization (WHO) said 29 countries this year have reported outbreaks, including 16 that are experiencing protracted activity. It said the outbreaks follow a spike in activity in 2021, which followed years of decline.

Much of the recent activity has come from countries in the Americas and Africa, with many of them reporting more cases and higher case-fatality ratios than in previous years.

The WHO said one concern is that 13 outbreaks are occurring in countries that didn't report any cases in 2021. Some hadn't reported cases in many years, while others aren't considered cholera-endemic areas.

Multiple outbreaks against the backdrop of complex humanitarian crises—made worse by climate change—is adding to global response challenges and pose risks of spread to other countries, the WHO said. Also, health officials are faced with limited supplies of cholera vaccine and healthcare systems that are stretched thin by juggling other health crises.

Aside from climate change and humanitarian crises, other drivers include surveillance gaps, supply chain problems, and limited resources, including oral cholera vaccine.

Currently, seven African nations are experiencing outbreaks. In the Middle East, outbreaks are occurring in Syria and Lebanon. In South Asia, Bangladesh is experiencing its largest outbreak since 2000, which is occurring before the monsoon season. Haiti is the hot spot in the Americas, and in the Western Pacific, the Philippines has reported localized outbreaks.

The WHO, which in October put the global risk of further spread of cholera as very high, urged countries to improve access to quick care, improve access to safe drinking water, and step up infection prevention and control in health facilities. It added that the oral cholera vaccine, currently used as a one-dose regimen to stretch supplies, should be used alongside improvements in water and sanitation.


This week's top reads