Seroprevalence and Molecular Characterisation of Human Hepatitis A virus in Serum Samples of Tunisian Patients with Clinical Symptoms of Viral Hepatitis

Gharbi-Khélifi, Hakima; Abid, Nabil; Beji, Abir; Bhiri, Leila; Harrath, Rafik; Sdiri, Khira; Billaudel, S.; Ferré, Virginie; Aouni, Mahjoub

doi:10.1007/s13337-012-0063-6

Cited by 9 publications

(12 citation statements)

References 36 publications

(40 reference statements)

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“…This finding is in agreement with those from previous seroprevalence studies (36,42). However, present data from the west-central region showed the same HAV pattern found in our previous study (4) conducted in different STPs from the same area which showed the highest number of positive samples in winter and autumn also.…”

Section: Discussionsupporting

confidence: 93%

“…Results of the phylogenetic analysis of HAV sequences obtained from wastewater samples were in accordance with several epidemiological studies showing the predominance of subgenotype IA in Tunisia over several years (4,31,42). Interestingly, some strains belonging to this subgenotype were closely related to European strains, confirming the circulation of this subgenotype variant in the Mediterranean region (49).…”

Section: Discussionsupporting

confidence: 86%

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Detection and Molecular Characterization of Hepatitis A Virus from Tunisian Wastewater Treatment Plants with Different Secondary Treatments

Ouardani

Turki

Aouni

et al. 2016

Appl Environ Microbiol

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Hepatitis A virus (HAV) is the main causative agent of hepatitis infection associated with waterborne outbreaks worldwide. In Tunisia, there is no specific surveillance system for HAV and current secondary wastewater treatment processes are unable to remove viral particles, which present a potential public health problem. Qualitative and quantitative analysis of HAV in 271 raw and treated wastewater samples from five sewage treatment plants (STPs) during 13 months was performed. Moreover, the efficiency of three secondary wastewater treatment processes (conventional activated sludge, extended aeration, and oxidation ditch activated sludge) was evaluated. Data obtained demonstrated that HAV is endemic in Tunisia and circulates with high prevalence in both raw (66.9%) and treated (40.7%) wastewater. HAV circulates throughout the year in the coastal areas, with the highest rates found during summer and autumn, whereas in central Tunisia, high levels were shown in autumn and winter. Total virus removal was not achieved, since no difference in mean HAV loads was observed in effluents (6.0 ؋ 10 3 genome copies [GC]/ml) and influents (2.7 ؋ 10 3 GC/ml). The comparison of the HAV removal values of the three different wastewater treatment methods indicates that extended aeration and oxidation ditch activated sludge had better efficiency in removing viruses than conventional activated sludge did. Molecular characterization revealed that the vast majority of HAV strains belonged to subgenotype IA, with the cocirculation of subgenotype IB in wastewater treatment plants that collect tourism wastewater. IMPORTANCEThis report provides important data on the incidence, behavior, seasonality, and genotype distribution of HAV in the environment in Tunisia, as well as the risk of infection derived from its occurrence in effluents due to inadequate wastewater treatment. In addition, these findings seem to confirm that the prevalence of HAV depends on socioeconomic level, sanitary conditions in the communities, sewage facilities, the locality, and the climate. The wide dispersion of HAV in effluents proves the inefficacity of the current wastewater treatment processes used in Tunisia to remove virus; therefore, establishment of tertiary treatment processes or replacement of the medium-charge activated sludge (conventional activated sludge) by the low-charge version (oxidation ditch activated sludge) is absolutely needed. Rapid detection of the HAV genome in wastewater may provide a timely warning sign to health authorities to implement population protection measures. H epatitis A virus (HAV) is one of the most important human waterborne viruses and constitutes the main cause of human enteric hepatitis transmitted via the fecal-oral route (1). It is widely prevalent in the world, as millions of new cases of HAV infections occur worldwide every year (2). It was previously demonstrated that areas with inadequate water supply and poor wastewater facilities and hygienic conditions generally have very high HAV prevalence (3, 4). Th...

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Section: Discussionsupporting

confidence: 93%

Section: Discussionsupporting

confidence: 86%

Detection and Molecular Characterization of Hepatitis A Virus from Tunisian Wastewater Treatment Plants with Different Secondary Treatments

Ouardani

Turki

Aouni

et al. 2016

Appl Environ Microbiol

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“…All clinical HAV strains from different regions of Sfax Governorate belonged to genotype IA [10]. This result is in an agreement with those of other Tunisian studies, which demonstrated that the predominant genotype still continues to be IA [15][16][17]. In addition, HAV sequences were closer to GBM reference strain (isolated in Germany) than to Asian sequences, suggesting a close genetic relatedness with HAV strains isolated in Mediterranean countries.…”

Section: Molecular Epidemiology Of Hepatitis a Virus Infectionsupporting

confidence: 85%

Epidemiological Aspects of Hepatitis A: Endemicity Patterns and Molecular Epidemiology

Gargouri¹,

Fki-Berrajah²,

Ayadi³

et al. 2020

Hepatitis a and Other Associated Hepatobiliary Diseases

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Improvements in hygiene and socioeconomic conditions in many parts of the world have led to an epidemiological shift in hepatitis A with a transition from high to low endemicity. Consequently, in these areas, higher proportion of symptomatic disease among adolescents resulting in large-scale community outbreaks has been described. In Tunisia, an increase in the average age at the time of infection has been reported, hence resulting in regular outbreaks, especially household and primary school epidemics. Molecular investigation of such outbreaks, based on the determination of viral genotype and genetic relatedness between hepatitis A virus (HAV) strains, is a useful tool to identify the potential source of HAV contamination but also to assess the virus molecular dynamics over time, such as the introduction of a new genotype or a specific clustering of HAV strains according to the geographical origin. In Sfax city, (Center-East of Tunisia), only HAV strains of genotype IA are circulating. In rural areas, HAV infection is still highly endemic with probably a water-borne transmission pattern. Nevertheless, the considerable genetic heterogeneity observed in urban areas highlights the changing pattern of hepatitis A epidemiology in these settings. Further molecular studies are strongly needed to better understand HAV epidemiology in Tunisia.

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“…More recently, other epidemiological studies, carried out from 2006 to 2008 with symptomatic patients, also detected high HAV seroprevalences during autumn and winter throughout the 3 years of the study (Gharbi-Khelifi et al 2012).…”

Section: Discussionmentioning

confidence: 66%

Efficiency of hepatitis A virus removal in six sewage treatment plants from central Tunisia

Ouardani

Manso

Aouni

et al. 2015

Appl Microbiol Biotechnol

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The efficiency of six Tunisian sewage treatment plants (STP) for the removal of hepatitis A virus (HAV) from wastewater was analysed in order to evaluate the potential risk for human health linked to reuse or discharge of treated wastewater into the environment. The STP utilize different biological wastewater treatments including primary treatment, which involves the physical removal of organic and inorganic solids, and secondary treatment that involves different processes, such as activated sludge or lagoon. Quantitative real-time reverse transcription polymerase chain reaction (RT-PCR) and conventional RT-PCR were used for the analysis of the 325 wastewater samples (163 raw and 162 treated) obtained. Results revealed highest contamination in west-central of Tunisia in raw wastewater with 62.96 % of samples positive for HAV and predominance during winter and autumn, whereas east-central region showed 50.62 % of positive samples with high prevalence from winter through summer. The quantitative analysis revealed a range between 4.29 × 10(1) and 1.24 × 10(5) RNA copies/mL in treated wastewater, showing clearly the inefficiency for total removal of HAV regardless of the treatment method used. The vast majority of HAV sequences belonged to the sub-genotype IA, except one that was assigned to sub-genotype IB.

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Seroprevalence and Molecular Characterisation of Human Hepatitis A virus in Serum Samples of Tunisian Patients with Clinical Symptoms of Viral Hepatitis

Cited by 9 publications

References 36 publications

Detection and Molecular Characterization of Hepatitis A Virus from Tunisian Wastewater Treatment Plants with Different Secondary Treatments

Detection and Molecular Characterization of Hepatitis A Virus from Tunisian Wastewater Treatment Plants with Different Secondary Treatments

Epidemiological Aspects of Hepatitis A: Endemicity Patterns and Molecular Epidemiology

Efficiency of hepatitis A virus removal in six sewage treatment plants from central Tunisia

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