Large study shows high protection of 3 vs 2 Pfizer COVID vaccine doses

A third Pfizer COVID-19 vaccine dose is 92% more effective in reducing severe COVID-related outcomes than two doses of the same vaccine received at least 5 months previously, according to a large real-world study late last week in The Lancet.

The study, conducted by researchers with the Clalit Research Institute in Israel and Harvard University, took place from Jul 30 through Sep 23, during Israel's fourth COVID-19 wave, when the Delta (B1617.2) variant was overwhelmingly predominant.

The scientists reviewed data from 728,321 Israelis aged 12 or above who had received the third Pfizer dose and matched them with the same number of people who had received the two-dose series at least 5 months before.

They found that, compared with people who received only two doses, those who received three doses of the vaccine had a 93% lower risk of COVID-related hospitalization, a 92% lower risk of severe COVID-19, and an 81% lower risk of COVID-related death 7 or more days after the booster. Booster-dose vaccine effectiveness was found to be similar across demographics.

The study also found that infection rates began to drop for each age-group 7 to 10 days after people in that group became eligible for a third dose.

Study coauthor Ben Reis, PhD, of Boston Children's Hospital and Harvard Medical School, said in a Lancet news release, "This careful epidemiological study provides reliable information on third-dose vaccine effectiveness, which we hope will be helpful to those who have not yet decided about vaccination with a third dose."

In a Lancet commentary on the study, K. Srinath Reddy, MD, president of the Public Health Foundation of India, wrote, "Although these reports strengthen the case for a booster dose of [the Pfizer COVID vaccine], there is no evidence yet to suggest that global policies related to other vaccines should be influenced by this experience."
Oct 29 Lancet study and commentary
Oct 29 Lancet news release


Patients with COVID-19, heart attack had higher risk of death

Patients diagnosed as having COVID-19 and a common type of heart attack had significantly higher rates of in-hospital death than uninfected patients, according to a retrospective study late last week in JAMA.

A researcher from Brown University led the study, which involved 80,449 patients at 509 US centers in the Vizient Clinical Database who had an ST-segment elevation myocardial infraction (STEMI) from January 2019 to December 2020.

Among the 76,434 patients who had an out-of-hospital STEMI, 551 tested positive for COVID-19, and 2,755 did not; 64.1% of these patients were aged 51 to 74 years, and 70.3% were men. Of the 4,015 patients who had an in-hospital STEMI, 252 had COVID-19 and 756 did not; 58.3% were 51 to 74 years old, and 60.7% were men.

Patients who had a STEMI outside of the hospital and tested positive for COVID-19 had a 15.2% death rate, compared with 11.2% in uninfected patients. The death rate of infected patients who had an in-hospital STEMI was 78.5%, versus 46.1% among non–COVID-19 patients.

Relative to out-of-hospital STEMI patients without COVID-19, infected patients had significantly higher combined rates of death, heart attack, and stroke (18.0% vs 13.2%). In-hospital STEMI patients with COVID-19 also had higher rates of those outcomes (80.9% vs 50.9%).

There was no significant difference in the likelihood of undergoing a stent insertion by COVID-19 status in the out-of-hospital STEMI group. But patients in the in-hospital STEMI group who had COVID-19 were significantly less likely than uninfected patients to have invasive diagnostic or therapeutic coronary procedures.

"Whether this change in approach resulted from a perceived futility of invasive therapy in these patients, perceived risk to health care workers, or both is unknown," the authors wrote.

In a commentary in the same journal, Alexander Fanaroff, MD, MHS; Jay Giri, MD, MPH, both of the University of Pennsylvania at Philadelphia, and Santiago Garcia, MD, of the Minneapolis Heart Institute Foundation, said that many patients with heart attack symptoms during the pandemic may have delayed care because they thought they had COVID-19 and should quarantine at home.

"As the pandemic continues and in potential future public health emergencies, it is imperative to emphasize the importance of timely care for patients with acute MI," they wrote.
Oct 29 JAMA study and commentary


CWD confirmed in east-central Wisconsin

The Wisconsin Department of Natural Resources (DNR) confirmed chronic wasting disease (CWD) in a deer in Fond du Lac County, in the east-central region of the state. The wild deer was found in the town Eldorado, which is within 10 miles of the Winnebago County border.

This is the first confirmed CWD detection in wild deer in Fond du Lac County. According to the DNR, a local landowner reported the deer—which was showing outward signs of the fatal prion disease—in early October.

In response to the detection, the DNR said it is expanding a ban on baiting and feeding in Fond du Lac and Winnebago counties due to CWD detections in adjoining counties within 10 miles of the county line.

CWD is a prion disease that affects cervids like deer, elk, and moose. The disease was first detected in wild deer in the United States in 1981 and has now been detected in 26 states.
Oct 29 Wisconsin DNR
press release


Multistate Salmonella outbreak tied to onions tops 800 cases

Late last week the Centers for Disease Control and Prevention (CDC) added 156 new cases to a multistate Salmonella Oranienburg onion outbreak. There are now 808 cases reported in 37 states and Puerto Rico.

The outbreak is linked to onions from ProSource Produce LLC and Keeler Family Farms and imported from the state of Chihuahua, Mexico, from Jul 1 to Aug 31.

No deaths have been reported in the outbreak, but there are 28 new hospitalizations, bringing the hospitalization total to 157. Illness-onset dates range from May 31 to Oct 13, and earlier investigations showed that 75% of 193 interviewed patients reported eating raw onions or dishes likely containing raw onions before they got sick.

Texas has the most cases with 185, followed by Oklahoma (107), and Virginia (60). Patients range in age from 1 to 101, with a median age of 37, and 57% are female.

According to the Food and Drug Administration (FDA), several retailers have recalled products that included the onions, including meal kit companies HelloFresh and EveryPlate.
Oct 29 CDC
Oct 27 FDA
recall list


H5N6 avian flu hospitalizes another person in China

Continuing a steady stream of human H5N6 avian flu cases, China reported another infection, this time involving a 58-year-old woman from the city of Yongzhou in Hunan province, according to a statement today from Hong Kong's Centre for Health Protection (CHP).

The woman had been exposed to a live-poultry market before her symptoms began on Aug 29. She was hospitalized on Aug 31, where she is listed in serious condition.

So far this year China has reported 27 H5N6 cases, more than half of the 51 cases it has reported since the first human case was detected in 2014. Though a few other Asian nations have reported H5N6 in poultry, China and Laos are the only ones to report infections in humans.

Most of China's H5N6 patients have a history of contact with poultry or poultry environments. In August, officials reported infections in a husband and wife who had both shopped at a live-animal market and had cooked and eaten a duck they bought there.
Nov 1 CHP statement

Stewardship / Resistance Scan for Nov 01, 2021

News brief

Canadian studies find pandemic-related drops in antibiotic prescribing

Antibiotic prescribing during the early COVID-19 months in Canada dropped sharply, according to two new studies, one that looked at retail pharmacy trends across the country and one that focused on outpatient prescribing patterns in Ontario.

In the first study, published in Clinical Microbiology and Infection, researchers examined antibiotic dispensing through retail pharmacies across the country from Nov 2014 to Oct 2020. They found that, during Canada's first 8 months of COVID-19 activity, the overall dispensing levels dropped by 26.5%, and the drop was even sharper for children. For comparison, the decline in the years before the pandemic—from 2015 to 2019—was just 3.0%.

Prescribing rates for antibiotics targeting respiratory infections declined more sharply than those targeting urinary tract and skin and other soft-tissue infections. The team said similar findings have been reported by the United States and United Kingdom and that decreased access to prescribers and public health measures during the early part of the pandemic that reduced communicable disease levels may have played roles.
Oct 29 Clin Microbiol Infect abstract

In the second study, researchers evaluated data from an antibiotic prescribing database to gauge trends in Ontario from January 2017 to December 2020, designating March to December of 2020 as the COVID-19 period.

They found a 31.2% drop in antibiotic prescriptions during the pandemic months. Their deeper look at the data revealed that the reduction in prescribing was driven more by fewer doctor's visits for respiratory than by less prescribing for respiratory indications.
Oct 30 Open Forum Infect Dis abstract


Israeli study reveals frequent antibiotic use in kids with RSV

Roughly a third of children hospitalized with respiratory syncytial virus (RSV) at a hospital in Israel over a 10-year period received unnecessary antibiotics, researchers reported last week in the Journal of Global Antimicrobial Resistance.

Among 1,227 children hospitalized at Hillel Yaffe Medical Center from 2008 through 2018 for RSV-bronchiolitis, which is a common cause of respiratory infections in Israeli children, 335 (27.3%) received unnecessary antibiotic treatment. But when they examined only children ascertained not to have a bacterial co-infection, unnecessary antibiotic treatment climbed to 33.4%. Among patients who had no bacterial cultures drawn, 19% received antibiotics.

Using a logistic regression model, the researchers identified several variables associated with unnecessary antibiotics. They included drawing of any bacterial culture (blood culture, urine culture, cerebrospinal culture), prior emergency room visit, lower oxygen saturation, higher body temperature, and abnormally rapid breathing. Girls and older children were also more likely to receive unnecessary antibiotics.

"The findings of this study indicate that the high rates of unnecessary antibiotic therapy in RSV-bronchiolitis patients may be largely due to the physicians' perception of disease severity," the authors wrote. "A better balance between prescribing and withholding antibiotics must be achieved to mitigate future rates of antibiotic resistance." 
Oct 28 J Glob Antimicrob Resist study

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