Prevalence of enteric viruses in wastewater in Egypt after the COVID-19 pandemic

Exploring hepatitis A dynamics in Israel, 2019-2022

BACKGROUND

Continuous monitoring of Hepatitis A Virus (HAV) may assist in identifying local outbreaks. The advent of the COVID-19 pandemic, which affected the circulation of numerous pathogens, may have also impacted the scope of HAV infections.

AIM

To investigate the incidence and environmental dissemination of HAV between 2019 and 2022 in Israel, a country with an anti-HAV vaccination program.

METHODS

HAV RT-PCR analysis was performed for all HAV cases and for 280 sewage samples collected in 2019-2022. Available amplified HAV fragments from clinical (n = 107) and sewage (n = 27) were also assessed by genotyping and phylogenetic analysis.

RESULTS

In 2019-2022, 158 individuals and 12.9 % (36/280) of sewage samples were HAV-RNA positive. Median age was 30 years (IQR 20.5-44); approximately half (51.9 %, 82/158) were males. Almost all patients (98.4 %, 124/126) were not vaccinated. Highest numbers were identified in 2019 (84 cases and 30 %, 21/71, positive sewage samples). In 2020, when three COVID-19 related lockdowns were implemented, 24 cases and 4.3 % (3/69) sewage samples were HAV-RNA positive. The number of HAV-RNA positive cases and positive sewage samples remained low in 2021-2022 (31 and 19 cases, 13.2 %, 9/68 and 4.2 %, 3/72 positive sewage samples, respectively). Sub-genotype IB dominated (90.7 %, 97/107 of cases and 81.5 %, 22/27 of sewage samples), and phylogenetic analysis of HAV samples demonstrated small transmission clusters of sequences from Jews, Bedouin Arabs and foreign workers. Sub-genotype IA was identified in 8.4 % (9/107) of cases and in 18.5 % (5/27) of sewage samples.

CONCLUSION

Combined clinical and environmental surveillance is optimal for monitoring HAV. In 2020, the circulation of HAV decreased, possibly following COVD-19 health restrictions. In subsequent years, the incidence remained low. Adults in risk-groups for HAV infection should be vaccinated to minimize HAV circulation.

Unveiling the Burden of Hepatitis A in Salerno, Italy: A Comprehensive 9-Year Retrospective Study (2015-2023) on the Seroprevalence of HAV Antibodies and Age/Sex Distribution

Background: Hepatitis A virus (HAV) infection is a significant global cause of viral hepatitis. At present, the anti-HAV vaccine in Italy is proposed exclusively for specific high-risk groups, and a universal vaccination program is not implemented. Objectives: This study aimed to assess the level of immunity against HAV in patients of both sexes across age groups ranging from 0 to 95 years admitted to the San Giovanni di Dio e Ruggi d'Aragona Hospital in Salerno, Italy, over a 9-year period (2015-2023). Methods: The total HAV seroprevalence by chemiluminescence Vitros system immunodiagnostics (ortho-diagnostics) was obtained by database analysis, stratifying patients for gender and age group in both the pre-pandemic (2015-2019) and pandemic (2020-2023) periods. Results: Out of 28,104 samples collected in 2015-2023, 20,613 resulted positive by total HAV immune screening, with a significant reduction in the annualized proportion of events during the pandemic period compared to the pre-pandemic period. HAV was more abundant in males than females in both periods (exceeding the 70%), with a statistically significant decrease in HAV in females in 2015-2019. The 61-70-year-old age group is more susceptible for both genders, with a strong deviation from the 41-50-year-old age group compared to the 51-60-year-old group. The pandemic period affected the number of analyzed samples in 2020. Conclusions: The study revealed high HAV seroprevalence, especially in males and individuals aged 61-70 years. There was a notable decrease in seroprevalence during the pandemic compared to pre-pandemic years. These results emphasize the need for ongoing monitoring and suggest that a universal vaccination program could address regional immunity gaps and lower disease incidence.

Molecular Evolution of GII.P31/GII.4_Sydney_2012 Norovirus over a Decade in a Clinic in Japan

Norovirus (NoV) genogroup II, polymerase type P31, capsid genotype 4, Sydney_2012 variant (GII.P31/GII.4_Sydney_2012) has been circulating at high levels for over a decade, raising the question of whether this strain is undergoing molecular alterations without demonstrating a substantial phylogenetic difference. Here, we applied next-generation sequencing to learn more about the genetic diversity of 14 GII.P31/GII.4_Sydney_2012 strains that caused epidemics in a specific region of Japan, with 12 from Kyoto and 2 from Shizuoka, between 2012 and 2022, with an emphasis on amino acid (aa) differences in all three ORFs. We found numerous notable aa alterations in antigenic locations in the capsid region (ORF2) as well as in other ORFs. In all three ORFs, earlier strains (2013-2016) remained phylogenetically distinct from later strains (2019-2022). This research is expected to shed light on the evolutionary properties of dominating GII.P31/GII.4_Sydney_2012 strains, which could provide useful information for viral diarrhea prevention and treatment.