Quick takes: US COVID-19 levels, H5N1 in cows, polio in 3 nations

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  • The latest data from the Centers for Disease Control and Prevention (CDC) show upticks in some markers the agency uses to track COVID-19, though overall activity remains muted. According to the CDC's COVID Data Tracker, test positivity is up 0.4% from the previous week and now at 4.5%, while the percentage of emergency department visits diagnosed with COVID rose by 16.2% and is at 0.5% overall. No changes were seen in the two severity indicators, hospitalizations and deaths, which both remain at low levels. COVID wastewater levels also remain low, but high levels are being reported in the West and in Florida. Variant proportion estimates show the JN.1 offshoots KP.3 and KP.2 now account for 47% of sequenced samples, up from 41.2% the previous week, while LB.1 makes up 14.9%.
  • The Michigan Department of Agriculture and Rural Development today announced the detection of H5N1 avian influenza in a dairy herd in Clinton County, the 25th affected dairy herd in the state. The outbreak total now stands at 87 herds in 11 states. Also today, the CDC posted updated recommendations for symptom monitoring in people exposed to H5N1-infected birds, cattle, or other animals. The guidelines call for local or state health departments to monitor symptoms in exposed farm workers for 10 days after exposure. "Monitoring exposed individuals can help to rapidly identify human cases, provide appropriate treatment, prevent onward spread, and help understand the scope of human risk," the agency said.
  • New polio cases were reported in three countries this week, according to the latest update from the Global Polio Eradication Initiative. Afghanistan and Pakistan each recorded one wild poliovirus type (WPV1) case, the fourth WPV1 case reported in each country this year. Also, Niger reported one circulating vaccine-derived poliovirus type 2 (cVDPV2) case, its second case this year. 

Study shows no link between stillbirths, COVID-19 vaccines

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Mikumi / iStock

A new study from Yale researchers in Obstetrics and Gynecology shows no link between stillbirth and COVID-19 vaccines. Moreover, pregnant women who had received COVID-19 vaccines in pregnancy were at a decreased risk of preterm birth.

The authors say the findings should offer further reassurance that COVID-19 vaccination is safe and useful in pregnancy. 

"The results of this robust case-control study can be used to reassure both pregnant patients and health care professionals that COVID-19 vaccination in pregnancy is not associated with an increased risk of pregnancy loss," said study author Anna Denoble, MD, in a press release.

The results of this robust case-control study can be used to reassure both pregnant patients and health care professionals

The study was based on outcomes seen in the Vaccine Safety Datalink, and compared receipt of the vaccine among women who had stillbirths or fetal death after 20 weeks gestation and those who had live births. 

Vaccines not associated with any negative birth outcomes 

A total of 55,591 people were included, and 23,517 (42.3%) received one or two mRNA COVID-19 vaccine doses during pregnancy. 

Overall, 38.4% of patients experiencing stillbirth received a COVID-19 vaccine in pregnancy, compared with 39.3% of those with live births.

For pre-term birth, vaccinated women had a rate of 6.4 per 100, compared to 7.7 per 100 for unvaccinated. COVID-19 vaccines were not associated with preeclampsia, gestational hypertension, or small-for-gestational age neonates.

"Results from this study provide additional evidence regarding the safety of mRNA COVID-19 vaccine administration during pregnancy, the authors concluded. 

Study ties prevalence of drug-resistant organisms to socioeconomic conditions

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MRSA bacteria

study in Texas found higher rates of antimicrobial-resistant (AMR) organisms in areas with higher levels of economic deprivation, researchers reported today in Clinical Infectious Diseases.

Using electronic health records from two large healthcare systems in the Dallas-Fort Worth metropolitan area, a team led by researchers from the University of Texas Southwestern Medical Center collected select patient bacterial culture results from 2015 to 2020. They chose five AMR organisms to represent potential community- and healthcare-associated acquisition, used residential addresses to geocode cultures and link them to socioeconomic index values, and identified geographic clusters of high and low AMR organism prevalence.

Among the 43,677 unique cultures collected, 43.5% were identified as methicillin-resistant Staphylococcus aureus (MRSA), 31% as extended-spectrum beta-lactamase (ESBL)–producing organisms, 11.3% as carbapenem-resistant Enterobacterales, 8.2% as vancomycin-resistant Enterococcus, and 5.9% as AmpC beta-lactamase producers. Significant clusters of all five organisms were found in areas with high levels of economic deprivation, as measured by the area deprivation index (ADI), and there was significant spatial autocorrelation between ADI and AMR prevalence.

The strongest correlation was observed for MRSA and AmpC, with 14% and 13%, respectively, of the variability in prevalence rates attributed to their relationship with the ADI values of the neighboring locations.

Tailored interventions may be needed

The study authors say several factors could explain why AMR organisms are more prevalent in areas with greater socioeconomic disparities. For example, people in areas with higher ADI may have poorer sanitation due to utility disruptions or poor plumbing and therefore be more likely to be exposed to bacteria, or may live in overcrowded settings that can contribute to the spread of infection. The practice of sharing "leftover" antibiotics with friends and family could also select for resistant organisms.

While further research is needed to delineate the relationship, they say the findings highlight the importance of addressing these disparities.

"This finding that ADI is associated with higher prevalence of AMR supports the need for tailored, local interventions for small neighborhoods including social programs that increase access to health insurance, along with public health campaigns discussing proper hygiene techniques to prevent the spread of disease within a household," they wrote.

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