Molecular characterization of hepatitis A virus from children hospitalized at a tertiary care centre in northwest India

Molecular characterisation of hepatitis A in the Western Cape province, South Africa in 2023

In 2023, passive laboratory-based surveillance showed an increase in hepatitis A virus (HAV) infection. We investigated hepatitis A incidence using the notifiable medical condition surveillance system (NMCSS) data and molecularly characterised positive blood samples from the Western Cape province for 2023. All HAV IgM seropositive cases from the NMCSS from 1 January to 31 October 2023 in South Africa were investigated. HAV RNA from blood samples that had tested positive for HAV IgM from Western Cape was amplified in the VP1/P2B junction and sequenced (3500Xl Genetic Analyser). Sequences were assembled, aligned (Sequencher) and analysed (Aliview 1.27 and MEGA11). Statistical analysis was performed using Excel and the CuSum2 Threshold to determine suspected outbreaks. In 2023, the incidence of HAV IgM was 6.28/100,000 in South Africa, with the highest incidence in Western Cape province (15.86/100,000). Children aged 5 to 14 years were affected the most in the Western Cape. The positive cases in the Western Cape were above the CuSum2 threshold from January to May 2023, with the highest incidence observed in the City of Cape Town Metropolitan (14.8/100,000). Genotyping was successfully performed on 92.7% (139/150) of serum samples, for which the IB sub-genotype was detected. Three primary mutations R63K, R71S and M104I were observed in more than 49% of the samples. Most of the samples sequenced belonged to patients residing in areas close to each other within the City of Cape Town Southern, Western, and Mitchells Plain sub-districts. The CuSum2 threshold method allowed the identification of suspected HAV outbreaks in the districts within the Western Cape in 2023 while genotyping identified clusters of sub-genotype IB. Genotyping could assist with determining the common source of infection during an outbreak, especially if coupled with epidemiological and geographical data. Further active surveillance can assist in investigating the HAV risk factors for targeted public health responses.

Comparison between immune-chromatography (ICT) and ELISA techniques for detection of anti-HAV antibodies among patients suspected to be infected with Hepatitis A virus (HAV)

Infection with Hepatitis A virus (HAV) is a significant cause of acute hepatitis, posing an important public health problem worldwide. This study aimed to compare the efficiency of the immune-chromatography test and the enzyme-linked immunosorbent assay (ELISA) in detecting infection with hepatitis A virus (HAV). For this purpose, 5 ml of blood was collected from 176 patients (92 males and 84 females) who attended the virology unit at Kirkuk General Hospital and the serological examination unit at the pediatric hospital, as well as private clinics in Kirkuk city for the presence of clinical signs or complaint directed towards infection doubt with hepatitis A virus (HAV), during the period between March 2020 and December 2021. The seropositive rate of anti –Hepatitis A immunoglobulin M antibody was 46(26.13%) of total patients of the study, while the ratio of the seronegative of HAV was 90(51.13%). The percentage of false-positive and false-negative results by immune-chromatography (ICT) was 34(19.38%) and 6(3.4%). These findings suggest that the fast test (ICT) is not a suitable screening test for detecting specific antibodies to the hepatitis A virus due to the high frequency of false-negative results caused by the test's low sensitivity and negative predictive value. This emphasizes employing ELISA or PCR methods to confirm hepatitis A virus diagnosis in public hospitals. Although ICTs are cheap, they alone are not useful in diagnosing and deciding treatment for patients infected with Hepatitis A virus, so it is recommended to use the ELISA test to confirm the diagnosis of infection and identify the Hepatitis A virus in public hospitals, healthcare units and blood transfusion centers. Keywords. Hepatitis A virus, Seroprevalence, immuno-chromatographic test, ELISA test, IgM

Currently circulating genotypes of Hepatitis A virus in South West, East and North East India, 2017-2018

Background

This study was carried out to understand the circulating genotypes of Hepatitis A virus (HAV) in South West, East and North East India during the period 2017-2018 as a part of acute febrile illness surveillance at the Manipal Institute of Virology.

Methods

Archived serum samples of 48 Hepatitis A confirmed cases were subjected to RNA extraction using QIAamp® Viral RNA Mini Kit (QIAGEN, Germany). The samples with molecular confirmation for HAV by reverse transcriptase real-Time PCR (Real Star® HAV RT-PCR Kit 2.0, Altona Diagnostics, GmbH, Hamburg, Germany) were further subjected to nested conventional PCR targeting the 5' UTR region. The purified PCR products were sequenced using Big Dye Terminator Kit (Applied Biosystems, USA), in a 3500 XL genetic analyzer (Applied Biosystems, USA). The edited sequences by means of MEGA X (MEGA version 10.1) were compared with reference sequences in the NCBI nucleotide database.

Results

From states of Assam, Goa, Gujarat, Karnataka, Kerala, Maharashtra, Odisha, Tamil Nadu and Tripura, 139 Hepatitis A and 33 Hepatitis E cases were reported during the study period. The median age of the acute Hepatitis A cases was 19 years (IQR 12.8-24) and most of the affected individuals were students between 10 and 19 years (52.5%). In the present study, 14 samples from Assam, Goa, Gujarat, Karnataka, Odisha, Kerala, Maharashtra and Tamil Nadu were genotyped as genotype IIIA by nested conventional polymerase chain reaction.

Conclusion

The circulating HAV genotype in South West, North East and East India between 2017 and 2018 was IIIA.