Quick takes: CDC to examine Chile H5N1 samples, H5N1 hits poultry in Senegal, more US peds flu deaths

News brief
  • The US Centers for Disease Control and Prevention (CDC) yesterday weighed in on Chile's first human H5N1 avian flu case, noting that a respiratory sample has been sent to the CDC for confirmation and testing. It said the source of the patient's infection is part of an ongoing investigation. In the 10 earlier human H5N1 cases reported since January 2022, all had exposure to poultry.
  • Senegal recently reported the appearance of highly pathogenic H5N1 in wild birds, and now the country has reported the virus at a commercial poultry farm, according to a notification from the World Organization for Animal Health (WOAH). The outbreak location is about 23 miles from where the virus was recently reported in wild birds. In a related development, Chile also reported another H5N1 outbreak at a commercial poultry farm, this time in the Biobio region in the central part of the country, according to a separate WOAH notification.
  • US flu activity remained low last week, with influenza B making up roughly one-third of cases, the CDC said today in its latest weekly update. It also reported four more pediatric flu deaths, raising the season's total to 138. The deaths occurred between October and March, and all four involved influenza A viruses.

Three African countries report more polio cases

News brief

Three countries in Africa reported new polio cases this week, all involving vaccine-derived strains, according to the latest weekly update from the Global Polio Eradication Initiative (GPEI).

The Central African Republic (CAR) reported five circulating vaccine-derived poliovirus type 2 (cVDPV2) cases, its first for 2023. The patients had January and February illness onsets and are from health regions 1 and 6. The CAR's cases this year have already reached its total for all of 2022.

In Chad, officials reported two cVDPV2 cases, bringing its total for the year to four. Paralysis onsets occurred in January and February in patients from Batha and Logone Oriental provinces.

Elsewhere, the Democratic Republic of Congo (DRC) reported 22 more cVDPV2 cases in patients with paralysis onsets in both 2022 and 2023, mainly from the eastern part of the country. The new cases lift the DRC's total for 2022 to 336 and the total for 2023 to 7. Also, the DRC reported 11 more circulating vaccine-derived poliovirus type 1 (cVDPV1) cases, also with paralysis onsets in both 2022 and 2023 and mainly involving patients in the country's east. The latest cases push the DRC's total for 2022 to 125 and its number for the current year to 3.

Study: Long COVID could involve factors other than SARS-CoV-2 infection

News brief

Researchers who compared rates of long COVID symptoms in young people with and without a history of mild SARS-CoV-2 infection found prevalence was equally high in the control group, suggesting contributions of other factors.

Researchers from Norway using a prospective cohort study design examined patients ages 12 to 25 from two counties who were enrolled between Dec 24, 2020 and May 18, 2021, a time when the Alpha variant was circulating. They included 404 people who tested positive for SARS-CoV-2 and 105 who tested negative. The team published its findings yesterday in JAMA Network Open.

The team evaluated the participants during the early convalescent stage and at 6-month follow-up. Study subjects underwent clinical exam, including pulmonary, cardiac, and blood tests to examine immunological and organ injury biomarkers. Researchers also conducted cognitive functional tests. They used the World Health Organization (WHO) definition for post COVID condition (PCC).

Prevalence of PCC 6 months after acute COVID infection was about 50%, but was equally high at 47% in the control group. The team didn't find any biomarkers specific to viral infection at 6-month follow-up. The main risk factor for PCC was symptom severity at baseline. Two psychosocial factors stood out as risk factors for PCC: low physical activity and loneliness.

The researchers concluded that the findings question the usefulness of the WHO's PCC case definition and suggest that factors labeled psychosocial should be considered as risk factors for persistent symptoms. "This does not imply that PCC is 'all in the mind,' or that the condition has a homogeneous, psychological etiology," the authors wrote. "Rather, there might be heterogeneous biological, psychological, and social factors engaged in triggering and maintaining the symptoms of the individual."

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