Death certificate analysis pushes European COVID toll 18% to 27% higher than official records

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COVID deaths in Europe — *Victoria Pickering / Flickr cc*

The proportion of COVID-19 deaths in central Europe in 2020 and 2021 would have been up to 18% to 27% higher if death certificates listing the virus as a contributing condition had coded it as the cause of death, estimates a new study published in PLOS One.

University of Warsaw-led researchers examined 187,300 death certificates from Austria, Bavaria (Germany), Czechia (Czech Republic), Lithuania, and Poland mentioning COVID-19 in 2020 and 2021. They performed a two-step analysis of cause-of-death association indicators (CDAIs) and contributing CDAIs to estimate the statistical strength of associations between COVID-19 and other conditions.

"Excess deaths reported to causes other than COVID-19 may have been due to unrecognised coronavirus disease, the interruptions in care in the overwhelmed health care facilities, or socioeconomic effects of the pandemic and lockdowns," the authors noted. "Death certificates provide exhaustive medical information, allowing us to assess the extent of unrecognised COVID-19 deaths."

Many possible reasons for undercount

A total of 15,700 death certificates listed COVID-19 as a contributing condition, and three of four recorded a statistically significant COVID-19 complication or pre-existing condition as the cause.

Unrecognised coronavirus deaths were equivalent to the entire surplus of excess mortality beyond registered COVID-19 deaths in Austria and the Czech Republic, and its large proportion (25–31%) in Lithuania and Bavaria.

"In Austria, Bavaria, Czechia, and Lithuania the scale of COVID-19 mortality would have been up to 18–27% higher had COVID-19 been coded as the underlying cause of death," the researchers wrote. "Unrecognised coronavirus deaths were equivalent to the entire surplus of excess mortality beyond registered COVID-19 deaths in Austria and the Czech Republic, and its large proportion (25–31%) in Lithuania and Bavaria."

The undercount may be attributable to a lack of COVID-19 testing, atypical disease course, misclassification, or deaths from other causes such as cardiovascular disease and cancers that may have risen as strained healthcare systems prioritized COVID-19 patients or fallen owing to the reduction of risk factors such as air pollution, traffic, or other infectious diseases.

"Finally, mortality may have increased due to harmful behaviours typical of the socioeconomic instability experienced by some groups during the pandemics, lockdowns and economic slowdown, such as abuse of noxious substances, suicides and accidents," the researchers wrote.

US COVID-19 activity continues to rise steadily

News brief

Lisa Schnirring

The latest COVID indicators from the US Centers for Disease Control and Prevention (CDC) today showed more rises, with wastewater detections trending upward in all regions of the country, especially the West and South.

nasal swabbing — *Banc d'Imatges Infermeres, Ariadna Creus i Àngel García / Flickr cc*

The state of the nation's COVID activity this week was marked by President Joe Biden's announcement that he had tested positive for the virus. A letter from Biden's doctor, Kevin O'Connor, DO, yesterday said the president is still experiencing mild upper respiratory symptoms and that he continues to take Paxlovid.

Surge in KP.3.1.1 detections

In its latest variant proportion projections, the CDC reported a big jump in KP.3.1.1 viruses, an offshoot of KP.3 that scientists this week said is poised to become dominant because of its higher infectivity and immune evasion. KP.3 and its relative, KP.3.1.1, together make up more than 50% of variant sequences.

Among early indicators, the national test positivity rose to 12.6% last week, up 1.2 percentage points from the previous week, and were highest in the West and lowest in the Middle Atlantic states. Emergency department visits for COVID were also up slightly.

Along with the CDC's report of high wastewater levels of SARS-CoV-2, WastewaterSCAN, a national wastewater monitoring system based at Stanford University in partnership with Emory University, notes that detections are in the high category, with no significant trend up or downward over the past 3 weeks. It said all regions of the country are in the high category, except for the Midwest, which is at the medium level.

Hospitalizations for COVID are increasing, especially in people ages 65 and older, the CDC said in its weekly respiratory virus snapshot. Deaths from COVID showed no change from the previous week.

H5N1 strikes another large layer farm in Colorado, dairy herd in Minnesota

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Lisa Schnirring

As Colorado continue its response to a highly pathogenic H5N1 avian flu outbreak at a massive egg-laying farm connected to five H5 illnesses in people working as poultry cullers, federal agriculture officials confirmed another outbreak at a large layer farm that houses 1.3 million birds.

layer chickens — *UGA CAES Extension, John Amis / Flickr cc*

Both of the layer farms are in Weld County in the northeastern corner of the state, where several outbreaks have been reported in dairy cattle.

In other developments, Minnesota's Board of Animal Health reported another affected dairy herd, which is located in Stearns County in the central part of the state.

Wastewater detection in Arkansas

In a new wastewater development, WastewaterSCAN reported a new H5 influenza detection in Arkansas involving the city of Harrison's wastewater treatment plant. No recent outbreaks or detections have been confirmed from the state.

Wastewater detections aren't able to determine the source of the virus. WastewaterSCAN's H5 tracking has detected the virus in nine other states, all but one of which (California) has reported dairy cattle or poultry outbreaks.

In other wastewater tracking, the Centers for Disease Control and Prevention said that, across the 2 weeks ending July 6, no states were at the high level for influenza A, which can't distinguish H5N1 but can be a surveillance signal for health officials to explore the source.

Zika can have long-term consequences for immune system

News brief

Stephanie Soucheray, MA

Only 5% of infants exposed to Zika virus in utero develop the physical or neurologic disabilities associated with congenital Zika syndrome, but new research published in eBioMedicine shows almost all children exposed to Zika in the womb may experience changes to the immune system.

The study is based on a small cohort of Zika-exposed children followed up by researchers from the Cleveland Clinic and elsewhere, led by Suan-Sin Foo, PhD. In a press release from the Cleveland Clinic, Foo said her research fills in a missing gap in the Zika landscape.

"The medical field has a very specific definition of congenital Zika syndrome. The children must have impaired skull or brain development," said Foo. "The rest of these kids may not even have a note on their chart mentioning that their mother was infected during pregnancy. Unless they're part of our study, they're essentially lost to the medical field."

The rest of these kids may not even have a note on their chart mentioning that their mother was infected during pregnancy.

Forty-two Zika-exposed infants (ZEI) assessed at birth and 20 children exposed to Zika during pregnancy (ZEC, for Zika-exposed children) and assessed at age 2 years in Brazil provided blood samples and were compared to healthy controls. Researchers found high elevated levels of inflammation, even 2 years after the Zika virus infection was cleared.

Altered response to childhood vaccines

Moreover, the 2-year-olds showed an altered immune response to childhood vaccines in T-cell expression, with notably reduced anti-Diphtheria toxin and anti-Clostridium tetani Immunoglobulin G levels against diphtheria, tetanus, and acellular pertussis and measles, mumps, and rubella vaccines.

The authors said their research will now shift to focusing on how to block Zika's effects during pregnancy. They added that their findings should encourage clinicians to broaden their understanding of congenital Zika syndrome.

"Our study clearly shows that there's much more to this condition than meets the eye. We need to expand diagnostic criteria and conduct more research to make sure these immunologically vulnerable children get the care they need," said Foo.