H5N6 avian flu sickens Chinese woman

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China has reported another H5N6 avian flu infection, which involves a 27-year-old woman from Sichuan province, marking the fifth such case of the year.

According to a statement from Hong Kong's Centre for Health Protection, the woman's symptoms began on July 20 and she was admitted for treatment on July 22. The report did not say how the woman was exposed to the virus or list her condition. Many of the earlier patients had been exposed to poultry or poultry environments before they got sick.

The illness lifts the global total to 86 cases since the virus was first detected in humans in 2014, most of them from China. H5N6 is known to circulate in poultry in some Asian nations, but only China and Laos have reported human cases, which are often severe or fatal.

Study shows no change in US dental antibiotic prescribing rates

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Dentist at work
Lily A. / Flickr cc

A retrospective study of US national data shows that dental antibiotic prescribing rates remained unchanged from 2012 through 2019, US researchers reported yesterday in Infection Control & Hospital Epidemiology.

Using data from the IQVIA Longitudinal Prescription Data set, researchers evaluated the total number of antibiotics prescribed by US dentists, the mean days' supply of antibiotics, and the annual provider-based antibiotic prescribing rate from 2012 through 2019, a period that saw revised guidelines for dental antibiotic prescribing and implementation of targeted antibiotic stewardship efforts in US dental settings.

Previous research has shown that roughly 10% of US outpatient antibiotic prescriptions are written by dentists, with penicillins accounting for 70% of all dental antibiotic prescriptions.

Amoxicillin, clindamycin most often prescribed

A total of 216 million antibiotics were prescribed by 241,106 dentists from 2012 through 2019, many of them for male patients (55%) and those aged 40 to 64 years (42%). The average provider-based prescribing rate for all antibiotics over the entire study period was 142,155 prescriptions per 1,000 dentists per year, with no significant trends observed. Amoxicillin and clindamycin were the most prevalent antibiotics prescribed (62.8% and 14.2%, respectively).

Significant increases in the prescribing rate were observed among dentists in the Northeast and among endodontists, periodontists, prosthodontists, and oral and maxillofacial surgeons. But the analysis also found that the mean days' supply of antibiotics declined over the study period by 0.023 days per 1,000 dentists per year, a finding the study authors say indicates fewer doses of antibiotics prescribed by dentists circulated in the community and that dentists are following recent guidelines recommending shorter durations.

Efforts to improve unnecessary prescribing by dentists and targeting dental specialists and prescribing of clindamycin may decrease overall antibiotic prescribing.

The authors note that the findings are discordant with medical clinician prescribing trends, which suggests more emphasis on stewardship is needed.

"Antibiotic stewardship efforts to improve unnecessary prescribing by dentists and targeting dental specialists and prescribing of clindamycin may decrease overall antibiotic prescribing rates by dentists," they wrote.

Impact of invasive E coli infections in older adults spotlighted

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E coli
CDC

An analysis of invasive extraintestinal pathogenic Escherichia coli disease (IED) in older patients found a substantial clinical burden, with considerable long-term consequences, researchers reported yesterday in BMC Infectious Diseases.

To describe and characterize the short- and long-term impacts of IED, which comprises sepsis, bacteremia, peritonitis, meningitis, and other infectious syndromes, researchers from Europe, Canada, and the United States analyzed data on patients aged 60 and older with either a positive E coli culture and one or more signs of sepsis or a positive E coli culture in urine with urinary tract infection and signs of sepsis. The primary outcomes analyzed were clinical outcomes, medical resource use, and E coli isolate characteristics.

A third of patients admitted to ICU

Overall, 19,773 patients with IED from October 2015 through March 2020 were included (mean age, 76.8 years; 67.4% female; 78.5% with signs of sepsis). The vast majority of encounters involved community-onset IED (94.3%) and required hospitalization (96.5%; mean duration, 6.9 days), with 32.4% of patients being admitted to the intensive care unit (mean duration, 3.7 days) and 8.6% requiring mechanical ventilation. Nearly all patients (99.3%) were treated with antibiotics and typically received several antibiotic courses.

Nearly two thirds (61.7%) of E coli isolates were resistant to one or more antibiotic category, and 34.4% were resistant to three or more antibiotic categories. Following their first IED encounter, 34.8% of patients were transferred to a skilled nursing/intermediate care facility, and 6.8% had died. During the 12-month observation period, 36.8% of IED patients were re-hospitalized, 2.4% had IED recurrence, and in-hospital death increased to 10.9%.

This burden is particularly high in the presence of antibiotic resistance.

The study authors say the findings are important given the global increase in E coli infections and rising rates of antibiotic resistance.

"The findings suggest that IED is associated with an acute burden during the initial hospital encounter and may lead to poor outcomes even after the encounter is resolved," the study authors wrote. "This burden is particularly high in the presence of antibiotic resistance, which is an important consideration for an increasing aging population."

Remote communities not protected from COVID-19

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COVID-19 health educators in Bolivia
Photo courtesy of UC Santa Barbara / Michael Gurven

Even the most remote, isolated communities in the Amazon fell prey to COVID-19 at a high rate, according to a new study in PLOS Biology. The study focused on the population of Tsimane, a voluntarily isolated community in Bolivia that is more than 60 miles from the nearest market town.

"Remote-living, small-scale populations are highly vulnerable to global diseases," said Tom Kraft, PhD, an anthropologist from the University of California Santa Barbara (UCSB) and the University of Utah, and the lead author of the study in a UCSB press release. "We can't rely on remoteness and voluntary isolation alone to mitigate risks—we need to plan to direct medical resources to these communities."

Predictions vs real-world outcomes

The study authors created a computer model to predict whether the population structure, movement patterns, and geographic location of Tsimane would prevent COVID-19 spread. The community is made up of 18,000 people who live in 95 villages spread along rivers and logging roads.

They predicted that without any interventions, 4 out of 5 people living in that community would be infected during the pandemic, likely because of crowded living conditions, multigenerational families, and poor access to medical care. Even if travel was reduced by 90%, infection rates among the Tsimane would only be cut by 15%, the models predicted.

We can't rely on remoteness and voluntary isolation alone to mitigate risks.

When models were compared to real-world outcomes, the authors found an overall empirical adjusted COVID positivity rate of 81.1% (crude positivity rate = 75.7%) across communities following the first wave of infections in 2020.

"Tests of multiple intervention scenarios suggest that mobility restrictions (e.g., collective isolation) have little impact unless behavioral change is rigidly enforced at extreme levels for both travel to town and between communities," the authors concluded, "whereas even minor reductions in transmissibility achieved through pharmaceutical and other interventions can effectively reduce disease spread and total outbreak size."

Quick takes: WHO mpox guidance, more Florida dengue, Powassan virus cases in Connecticut

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  • The World Health Organization (WHO) yesterday published standing recommendations to guide countries in the battle against mpox. It said the new guidance replaces temporary recommendations the WHO put in place when it declared the end of the public health emergency of international concern in May. The standing recommendations, put together by the WHO's review committee, cover seven main areas to control and eliminate the virus, from having national plans in place to working toward equitable access to tests, treatment, and vaccine.
  • The Florida Department of Health (Florida Health) this week reported four more locally acquired dengue cases, raising the year's total to 15. The new cases are from Hardee, Miami-Dade, and Polk counties. Most of the earlier cases were from Miami-Dade County. Florida Health said Hardee and Polk are under a mosquito-borne illness advisory. Miami-Dade is among the counties that are under an alert.
  • Connecticut's health department this week reported four Powassan virus infections, marking the state's first cases of the tick-borne virus of the year. Two of the patients are men ages 60 and older from Middlesex and Litchfield counties who were sick in early July. The other two are women ages 50 and older from Windham and Litchfield counties who were sick in late July. All patients had known tick bites and were hospitalized for neurologic symptoms. The patients were discharged and are recovering. In 2022, Connecticut reported six Powassan virus illnesses, two of them fatal. The disease, mainly spread by black-legged (deer) ticks, causes symptoms that range from headache to encephalitis. There is no treatment. Most cases are reported from Great Lakes and northeastern states.

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