Cambodia's health ministry has reported another human infection from H5N1 avian influenza, part of an uptick in similar cases that began in 2023.

The patient is a 17-year-old girl from Kampot province, according to a ministry statement translated and posted by Avian Flu Diary, an infectious disease news blog. Kampot province is in southern Cambodia. The girl is hospitalized in the intensive care unit and is improving.

An investigation found that about 5 days before the girl's symptoms began, there were seven dead chickens at her home.

Cambodia has now reported 5 cases for 2024 and a total of 11 since February 2023, following nearly a decade with no human infections. Genetic sequencing on samples from several cases has revealed that the virus belongs to an older H5N1 clade (2.3.2.1c) that still circulates in poultry in some Asian countries, including Cambodia. It is different from the newer H5N1 clade (2.3.4.4b) that is currently affecting wild birds and poultry in multiple world regions, including the United States.

Hong Kong reports imported H9 case

Elsewhere, Hong Kong's Centre for Health Protection (CHP) today reported an influenza A H9 case, which involves a 22-month-old girl who had recently visited the city of Zhongshan in mainland China's Guangdong province. Her symptoms began on February 15, and she was seen at a hospital the next day but was not admitted. Plans are under way for her to receive care in hospital isolation.

An investigation revealed that she had no direct contact with poultry during her incubation period while visiting the mainland, nor did she eat undercooked poultry or have contact with sick people. One of her home contacts had a sore throat on February 17 that subsided.

The CHP said novel H9 flu virus infections, including H9N2, are typically mild. Hong Kong has reported nine cases since 1999, and its most recent case—from 2020—was also imported.

A new research letter in JAMA Network Open demonstrates that pre-COVID disparities in all-cause mortality have largely persisted after the acute phase of the pandemic, as patterns have largely returned to baseline.

The study examined annualized age-standardized death rates (ASDRs) among major demographic groups in the United States from March 2018 through May 2023. Sex, race and ethnicity, metropolitan status, and region were all considered.

The authors compared mortality ratios between four periods: One year prior to the pandemic, the first and second years of the pandemic (before and after widespread vaccination), and the post-acute Omicron-dominant phase of the pandemic.

American Indian, Alaskan Native groups hit harder

During the pandemic, mortality rates increased significantly for men, people of color, non-urban residents, and people in the South and West. In almost all groups, levels returned to prepandemic levels by fourth period analyzed. However, the authors said a notable change was that American Indian or Alaska Native ASDRs compared to White mortality was 1.02 (1.01-1.03) to 1.20 (1.18-1.21) or higher in both acute pandemic years.

"Death rate ratios during the postacute period generally returned to prepandemic levels," the authors said. "Although mortality remains somewhat higher than before the pandemic, this additional mortality is largely proportional to 2018-2019 mortality with respect to major demographic comparisons.

This continuity suggests that these disparities are persistent; even a pandemic-level mortality shock does not permanently alter them.

"This continuity suggests that these disparities are persistent; even a pandemic-level mortality shock does not permanently alter them."