Application of an Optimized Direct Lysis Method for Viral RNA Extraction Linking Contaminated Dates to Infection With Hepatitis A Virus

Abstract

Consumption of dates has not been considered a common risk of hepatitis A virus (HAV) infection. In January 2018, an outbreak of hepatitis was identified with cases resident in all regions of Denmark. All the detected strains belonged to HAV genotype 3A. Epidemiological investigations through patients' interviews, case-control and traceback studies pointed toward different batches of dates from a single producer as the vehicle of infection. Boxes of dates from suspected batches were collected from homes of patients and healthy families and analyzed using a recently reported optimized direct lysis method, consisting of simultaneous viral RNA elution and extraction from dates followed by purification of the nucleic acids. Extracts were analyzed for HAV and norovirus (NoV) RNA using RT-qPCR, while detected HAV were genotyped by Sanger sequencing. Among 20 nucleic acid extracts representing eight batches of dates, RNA of HAV (9.3 × 10 2 genome copies/g) and NoV genogroup (G)II (trace amounts) were detected in one batch, while NoV GII RNA (trace amounts) was detected in another. Average extraction efficiency of spiked process control murine norovirus was 20 ± 13% and the inhibitions of RT-qPCR detection of NoV GI, NoV GII, and HAV were 31 ± 34, 9 ± 9, and 3 ± 7%, respectively. The HAV genome detected in the dates matched by sequence 100% to the HAV genotype 3A detected in stool samples from cases implicated in the outbreak. This confirmed, to our knowledge, for the first time a sequence link between HAV infection and consumption of contaminated dates, suggesting dates to be an important vehicle of HAV transmission.

An outbreak of hepatitis A virus infection in a secondary school in England with no undetected asymptomatic transmission among students

“…These four cases were residents of other regions (South East and West Midlands) and known to be linked to consumption of date fruits. Contamination of date fruits is known to be associated with outbreaks of HAV [ 12 , 13 ].…”

“…A confirmed case was defined as a resident of City B (or who had visited City B) on or after 13 May 2019 and who was HAV IgM-positive. A probable case was defined as a resident of City B (or who had visited City B) on or after 13…”

Development of a Reverse Transcription-Recombinase Polymerase Amplification Assay for Duplex Detection of Foodborne Viruses in Oysters

“…Before applying RT-RPA to on-site detection of foodborne viruses in under-equipped situations, it is also necessary to facilitate procedures for nucleic acid extraction. RT-RPA was shown to be tolerant to highly impure samples (Rajiuddin et al, 2020). Unlike RT-RPA, RT-PCR did not tolerate inhibitory compounds present in the oyster extract.…”

“…A reduced need of complicated designed primers and time makes RPA more attractive than LAMP. Unlike PCR, the reactions are unaffected by inhibitors found in food, enabling immediate detection in a very short time (Rajiuddin et al, 2020). Moreover, the sensitivity and specificity of RPA have been shown to be comparable to those of conventional PCR assays (Daher et al, 2016).…”

Hepatitis A outbreak associated with consumption of dates, England and Wales, January 2021 to April 2021

“…HAV is not endemic in the UK and is mostly related to recent travel to countries with higher rates of hepatitis A. European countries are also considered to be non-endemic or have low endemicity [3]. A number of outbreaks including multi-country outbreaks associated with imported food products have been reported in the last decade, including examples involving pomegranate arils [4], dried tomatoes [5][6][7], berries [8,9] and dates [10].…”