Risk of Hepatitis E from pigs or pork in Canada

The role and importance of pigs and pork as sources of zoonotic hepatitis E virus (HEV) has been debated in Canada and abroad for over 20 years. To further investigate this question, we compiled data to populate a risk profile for HEV in pigs or pork in Canada.

pig-barfblogWe organized the risk profile (RP) using the headings prescribed for a foodborne microbial risk assessment and used research synthesis methods and inputs wherever possible in populating the fields of this RP. A scoping review of potential public health risks of HEV, and two Canadian field surveys sampling finisher pigs, and retail pork chops and pork livers, provided inputs to inform this RP. We calculated summary estimates of prevalence using the Comprehensive Meta-analysis 3 software, employing the method of moments.

Overall, we found the incidence of sporadic locally acquired hepatitis E in Canada, compiled from peer-reviewed literature or from diagnosis at the National Microbiology Laboratory to be low relative to other non-endemic countries. In contrast, we found the prevalence of detection of HEV RNA in pigs and retail pork livers, to be comparable to that reported in the USA and Europe. We drafted risk categories (high/medium/low) for acquiring clinical hepatitis E from exposure to pigs or pork in Canada and hypothesize that the proportion of the Canadian population at high risk from either exposure is relatively small.

Risk profile of Hepatitis E virus from pigs or pork in Canada

October 2016, Transboundary and Emerging Diseases, DOI: 10.1111/tbed.12582

https://www.researchgate.net/publication/308961418_Risk_Profile_of_Hepatitis_E_Virus_from_Pigs_or_Pork_in_Canada

 

17 sickened with Hepatitis E linked to undercooked pig-liver stuffing

Background – On 11 December 2013, 3 clustered cases of hepatitis E were reported on a coastal island in Brittany. Cases had consumed spit-roasted and stuffed piglet during a wedding meal. The raw stuffing was partly made from the piglet liver. Investigations were carried out to identify the source and vehicle of contamination, and evaluate the dispersion of the hepatitis E virus (HEV) in the environment.

spit-roast-pigMethods – A questionnaire was administered to 98 wedding participants who were asked to give a blood sample. Cases were identified by RT-PCR and anti-HEV serological tests. A retrospective cohort study was conducted among 38 blood sampled participants after the exclusion of participants with evidence of past HEV immunity. Relative risks (RR) with their 95% confidence intervals were calculated based on foods consumed at the wedding meal using univariate and multivariable Poisson regressions.

The human HEV strains were compared with the strains detected in the liquid manure sampled at the farm where the piglet was born and at the inlet of the island wastewater treatment plants.

Results – 17 cases, including 3 confirmed cases, were identified and 70.6% were asymptomatic. Acute HEV infection was independently associated with piglet stuffing consumption (RR=1.69 [1.04-2.73]). Human strains from the index cases, veterinary and environmental HEV strains were identical.

Discussion – The outbreak was attributable to the consumption of an undercooked pig liver-based stuffing. After infection, the cases have probably become a temporary reservoir for HEV, which was detected in the island’s untreated wastewater.

Hepatitis E outbreak associated with the consumption of a spit-roasted piglet, Brittany (France), 2013

Épidémie d’hépatite E associée à la consommation d’un porcelet grillé à la broche, Bretagne, 2013. Bull Epidémiol Hebd. 2016;(26-27):444-9

Y Guillois, F Abravanel, T Miura, N Pavio, V Vaillant, S Lhomme, et al.

http://invs.santepubliquefrance.fr/beh/2016/26-27/2016_26-27_3.html

Hep E? From pigs? In Corsica?

To the Editor: In Western countries, human infection with hepatitis E virus (HEV) is mostly autochthonous and zoonotic through ingestion of contaminated food or direct contact with infected animals and very occasionally is imported from regions to which it is endemic to humans (tropical and subtropical areas) (1). Domestic pigs and wild boars are important zoonotic reservoirs of HEV worldwide (2).

pigwapplesmIn continental France, grouped cases of hepatitis E have been described after ingestion of Corsican specialties made with raw pig liver known as ficatelli, traditionally eaten grilled or raw after curing (3,4). A survey of French food products detected HEV RNA in 30% of ficatelli samples (5). A recent nationwide study of blood donors in France showed a high (>60%) HEV seroprevalence in Corsica, suggesting local hyperendemicity (6). Estimated prevalences of HEV RNA from wild boars and domestic pigs in Corsica were 2.3% and 8.3%, respectively (F. Jori, unpub. data). We aimed to evaluate, at a molecular level, the role of local wild boars and domestic pigs from Corsica in human infections or food contaminations.

We retrieved partial sequences of HEV open reading frame 2 capsid (7) from samples from 8 wild boars hunted during 2009–2013 and from 2 domestic pigs collected at a slaughterhouse in 2013 (F. Jori, unpub. data) and compared them with sequences available in GenBank. This genomic region is used frequently in phylogeny and reflects the diversity of HEV (8). After alignment with reference sequences for subtyping (9) and their closest sequences, we constructed a phylogenetic tree (Figure). All 10 sequences belonged to HEV genotype 3 and were distributed into 3 distinct clusters.

Cluster 1, subtype 3c, comprised 4 wild boar sequences (FR-HEVWB-1-91, FR-HEVWB-3-07, FR-HEVWB-7-114, FR-HEVWB-8-115) that had 96%–97% nt identity. These sequences were identified during 3 successive hunting seasons (2009, 2010, and 2013) in the same hunting area, suggesting that HEV sequences can be stable, with limited genetic variability, during at least 4 years in a local population of wild boars. These sequences were close to HEV wild boar sequences from Belgium (GenBank accession no. KP296177) and Germany (GenBank accession no. FJ705359; 3c reference sequence). A possible introduction of wild boars from northeast continental France into Corsica during the 1990s could explain such similarity (C. Pietri, pers. comm.). Two human cases reported in southeastern France (GenBank accession nos. GQ426997, KJ742841) in 2008 and 2009 also aggregated within this cluster (94%–95% nt identity), indicating possible zoonotic transmissions from wild boars to humans.

Cluster 2 comprised 2 wild boar sequences (FR-HEVWB-2-101 and FR-HEVWB-6-75) with 99.3% nt similarity, collected in 2009 and 2012 from the same geographic area (Haute Corse, <10 km apart). This cluster is distant from the subtypes assigned by Smith et al. (9) and shows <86.5% nt identity with reference sequences (Figure), indicating a possible local and stable evolution in space and time.

Cluster 3, subtype 3f, comprised sequences isolated from wild boars and domestic pigs from Corsica, humans from continental France, and 1 food sample from Corsica. The 2 domestic pig sequences (FR-SHEV-2B-1-182, FR-SHEV-2B-2-190) were 100% identical and shared 97.5% nt identity with a wild boar sequence (FR-HEVWB-4-104), suggesting transmission between domestic and wild pigs. These 2 swine sequences shared 96% nt identity with a sequence amplified in 2011 from a ficatellu sample (FR-HEVFIG-3; GenBank accession no. KJ558438) (5) from the same geographic area of Corsica (Haute Corse) and 96% nt identity with an isolate from a patient with acute hepatitis E recorded in France in 2009 (GenBank accession no. JF730424). In addition, the wild boar sequence in this cluster (FR-HEVWB-4-104) shared 96.4% nt identity with the same ficatellu sample and 97.1% nt identity with the same patient in France. This finding suggests that some locally produced ficatelli could be contaminated with HEV from local domestic pigs or wild boars. The human infection also suggests that zoonotic transmission might have occurred through contact with local pig or wild boar reservoirs or through ingestion of contaminated food products. No additional information is available about this human case that might attribute the contamination to 1 of the sources.

Also in cluster 3, another Corsican wild boar sequence (FR-HEVWB-5-117), isolated in 2011, shared 96.2% and 95.7% nt identity with 2 human sequences identified from continental France in 2013 (GenBank accession no. KR027083) and 2009 (GenBank accession no. JF730424 FR-HuHEV-09AL38). This finding again suggests a zoonotic origin for these human cases. Cluster 3 illustrates well a possible path of transmission between wildlife, domestic pigs, food, and human infection and the potential for dissemination of HEV outside Corsica.

pig.sex_Our results provide evidence suggesting a dynamic exchange of HEV between domestic and wild swine reservoirs and possibly resulting in transmission from those reservoirs to humans through ingestion of infected food products. These animal reservoirs are common and abundant (http://www.oncfs.gouv.fr/IMG/file/mammiferes/ongules/ongules_sauvages/TCD/haute_corse_ongules_sauvages_tableau_departemental.pdfhttp://draaf.corse.agriculture.gouv.fr/IMG/pdf/Chiffres_cles_Corse-2015_cle825d93.pdf) and represent a sustainable source of HEV exposure in Corsica.

Nicole Pavio , Morgane Laval, Oscar Maestrini, François Casabianca, François Charrier, and Ferran Jori

Author affiliations: ANSES (French Agency for Food, Environmental and Occupational Health and Safety); Maisons-Alfort, France (N. Pavio); INRA (National Institute for Agricultural Research); Maisons-Alfort (N. Pavio); University Paris 12, National Veterinary School, Maisons-Alfort (N. Pavio); INRA, Corte, France (M. Laval, O. Maestrini, F. Casabianca, F. Charrier); CIRAD (Agricultural Research for Development); Montpellier, France (F. Jori); Botswana University of Agriculture and Natural Resources, Gaborone, Botswana (F. Jori)

Acknowledgments

We are grateful to Gaël Stéphant for technical assistance in swine sample analysis. We thank Christian Pietri for sharing his knowledge on the origin of wild boar population in Corsica.

Part of the study including wild boar and domestic pig sample analysis was supported by the European Union Seventh Framework Program (FP7/2007-2013) under grant agreement no. 278433-PREDEMICS and grant agreement no. 311931 (ASFORCE).

References

1.Pavio N, Meng XJ, Renou C. Zoonotic hepatitis E: animal reservoirs and emerging risks. Vet Res. 2010;41:46. DOIPubMed

2.Thiry D, Mauroy A, Pavio N, Purdy MA, Rose N, Thiry E, Hepatitis E virus and related viruses in animals. Transbound Emerg Dis. 2015;n/a; Epub ahead of print. DOIPubMed

3.Colson P, Borentain P, Queyriaux B, Kaba M, Moal V, Gallian P, Pig liver sausage as a source of hepatitis E virus transmission to humans. J Infect Dis. 2010;202:825–34. DOIPubMed

4.Renou C, Roque-Afonso AM, Pavio N. Foodborne transmission of hepatitis E virus from raw pork liver sausage, France.[Erratum in: Emerg Infect Dis. 2015;21:384. ]. Emerg Infect Dis. 2014;20:1945–7.DOIPubMed

5.Pavio N, Merbah T, Thébault A. Frequent hepatitis E virus contamination in food containing raw pork liver, France.Emerg Infect Dis. 2014;20:1925–7. DOIPubMed

6.Mansuy JM, Gallian P, Dimeglio C, Saune K, Arnaud C, Pelletier B, A nationwide survey of hepatitis E viral infection in French blood donors. Hepatology. 2016;63:1145–54. DOIPubMed

7.Rose N, Lunazzi A, Dorenlor V, Merbah T, Eono F, Eloit M, High prevalence of hepatitis E virus in French domestic pigs.Comp Immunol Microbiol Infect Dis. 2011;34:419–27. DOIPubMed

8.Lu L, Li C, Hagedorn CH. Phylogenetic analysis of global hepatitis E virus sequences: genetic diversity, subtypes and zoonosis. Rev Med Virol. 2006;16:5–36. DOIPubMed

9.Smith DB, Simmonds P, Izopet J, Oliveira-Filho EF, Ulrich RG, Johne R, Proposed reference sequences for hepatitis E virus subtypes. J Gen Virol. 2016;97:537–42. DOIPubMed

Possible foodborne transmission of Hepatitis E virus from domestic pigs and wild boars from Corsica

Emerging Infectious Diseases; Volume 22, Number 12—December 2016; DOI: 10.3201/eid2212.160612

Pavio N, Laval M, Maestrini O, Casabianca F, Charrier F, Jori F.

http://wwwnc.cdc.gov/eid/article/22/12/16-0612_article

To all the pregnant ladies: Hepatitis E is a risk

It is of great concern that pregnant women with acute viral hepatitis (AVH) type E have serious consequences. This study aimed to estimate the case-fatality risk (CFR) and potential risk factors of pregnant women with AVH type E.

We searched the PubMed, EMBASE, and Web of Science databases for studies containing data on CFR in pregnancy with AVH type E. A pooled estimate of CFR was calculated using a random-effects model. Potential sources of heterogeneity were explored using subgroup analysis, sensitivity analysis, and meta-regression. We identified 47 eligible studies with a total African and Asian population of 3968 individuals. The pooled CFRs of maternal and fetal outcomes were 20·8% [95% confidence interval (CI) 16·6–25·3] and 34·2% (95% CI 26·0–43·0), respectively. Compared with these, the pooled CFR was highest (61·2%) in women with fulminant hepatic failure (FHF). Community-based surveys had lower pooled CFR (12·2%, 95% CI 9·2–15·6) and heterogeneity (25·8%, 95% CI 20·1–32·0) than hospital-based surveys. Univariate analysis showed that hospital-based surveying (P = 0·007), and patients in the third trimester of pregnancy or with FHF (P < 0·05), were significantly associated with CFR. Intrauterine fetal mortality (27·0%) was statistically higher than neonatal mortality (3·9%).

Control measures for HEV infection would reduce feto-maternal mortality in Asia and Africa.

Case-fatality risk of pregnant women with acute viral hepatitis type E: a systematic review and meta-analysis

Epidemiology and Infection, Volume 144, Issue 10, July 2016, pp. 2098-2106, DOI: http://dx.doi.org/10.1017/S0950268816000418

Jin, Y. Zhao, X. Zhang, B. Wang, P. Liu

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=10375512&utm_source=Issue_Alert&utm_medium=RSS&utm_campaign=HYG

Raw pork liver a risk factor for hepatitis E in France

In France, the number of confirmed autochthonous hepatitis E (HE) cases has shown a substantial increase since 2006. In 2010, a descriptive study of acute autochthonous laboratory-confirmed HE cases was implemented in order to generate hypotheses about transmission modes and contamination sources.

raw.pork.liverAcute autochthonous HE cases confirmed by the National Reference Centre (CNR) were interviewed on exposures in the 2 to 10 weeks before illness onset. Clinical, biological and epidemiological characteristics were documented for 139 autochthonous cases.

Sixty-five per cent of them resided in southern France, 59% reported underlying conditions and 74% were infected by HEV subtype 3f. Consumption of raw pig-liver products during the incubation period was more frequent among cases in southern (47%) than in northern (25%) France. HE is a frequent infection, more prevalent in Southern France, where cases frequently report the consumption of raw pork-liver products. A case control study will determine the fraction of HE cases attributable to the consumption of such products and other risk factors.

Descriptive study of autochthonous cases of hepatitis E cases, France, 2010

Couturier E, De Valk H, Letort MJ, Vaillant V, Nicand E, Tessé S, Roque-Afonso AM

Saint-Maurice : Institut de veille sanitaire

http://www.invs.sante.fr/Publications-et-outils/Rapports-et-syntheses/Maladies-infectieuses/2015/Etude-descriptive-des-cas-autochtones-d-hepatite-E-France-2010#panel2

Japan to ban restaurants from serving raw pork

The central government will ban restaurants from serving raw pork starting in mid-June, following a similar ban in 2012 on beef liver, the health ministry said Wednesday.

raw.porkRestaurants have increasingly turned to pork after the ban on raw beef liver.

The ministry said it would now require pork to be heat-sterilized to prevent food poisoning. It will also ban retailers from selling pork for raw consumption.

The Health, Labor and Welfare Ministry cited the possibility that pigs’ innards could be tainted with the hepatitis E virus, which causes liver inflammation, as the reason for the ban.

Under the new requirements, pork will have to be heated for at least 30 minutes at 63 degrees, or be heat-sterilized in other ways with a similar effect, the ministry said.

Violators will face up to two years in jail or a ¥2 million fine, it added.

The ministry will also urge consumers not to eat raw pork, saying the meat should be heated for at least a minute at 75 degrees.

The number of hepatitis E patients hit a record high of 146 in 2014 from 55 in 2011, with pork the most likely cause among foodstuffs, according to data compiled by the National Institute of Infectious Diseases.

One in 10 UK sausages ‘carries risk of Hepatitis E virus’

One in 10 sausages and processed pork meat products in England and Wales could cause hepatitis E virus (HEV) infection if undercooked, experts warn.

There has been an “abrupt rise” in the number of cases in England and Wales as people do not realise the risk, scientists advising the government say.

Sausages should be cooked for 20 minutes at 70C to kill the virus, they said.

Although serious cases are rare, HEV can cause liver damage or be fatal.

Official government figures show there were 124 confirmed cases of HEV in 2003, which rose to 691 cases in 2013. There were 461 cases in the first six months of this year.

Symptoms include jaundice and sometimes tiredness, fever, nausea, vomiting and abdominal pain.

Most people will get over the virus, although for some, such as those with an immune deficiency disorder, or pregnant women, it can prove fatal.

Hepatitis E prevalent in French raw pork liver products

Hepatitis A is a commonly known pathogen in the food safety world – hepatitis E isn’t. There have  been a few papers detailing illnesses and outbreaks linked to the uncommon viral pathogen (mostly all out of Europe and Asia).The November issue of Emerging infectious Diseases has a paper that shows high prevalence of hep E in French raw pork liver products (used by some fancy restaurants).Screen Shot 2014-10-09 at 2.06.51 PM

Frequent hepatitis E virus contamination in food containing raw pork liver, Franc

Emerging Infectious Diseases, Volume 20, Number 11, November 2014

Nicole Pavio, Thiziri Merbah, and Anne Thébault

http://wwwnc.cdc.gov/eid/article/20/11/14-0891_article

Highlights:

Food products containing raw pork liver are suspected to be vehicles for transmission of hepatitis E virus. Four categories of food products, comprising 394 samples, were analyzed to determine hepatitis E virus prevalence. Virus was detected in 3%–30% of the different categories. Phylogenetic analysis showed high identity with human and swine sequences.

HEV is the only hepatitis virus that can infect species other than primates. HEV infects many animal species, especially pigs, in which a very high prevalence has been described (2). Infections acquired in Western countries involve strains that are genetically similar to local swine strains, suggesting an autochthonous origin. Although water is the main vector of contamination in countries to which HEV is endemic, the origin of sporadic cases in other areas is more likely zoonotic. Direct contact with infected animals and consumption of infected meat are possible transmission pathways (2).

In 2011, four different categories of food products in France that were marketed by the food industry were identified as containing raw pork liver and sold to consumers to be eaten without cooking. These 4 categories were 1) figatellu and fitone, 2) dried salted liver, 3) quenelle and quenelle paste, and 4) dried or fresh liver sausages. HEV can be heat-inactivated by thorough cooking at 71°C for 20 min (9); however, consumers might not apply such precise thermal treatment. Thus, these food products might be able to transmit HEV. All 4 categories were local regional culinary specialties from eastern or southeastern France.

Screen Shot 2014-10-09 at 2.04.22 PM

Does Hepatitis E come from food?

A UK report concludes that 10 per cent of sausages sampled were found to contain Hepatitis E and there is “increasing evidence’ that hepatitis E is a foodborne infection.

The infection was once considered very rare but cases have risen by sausage.grillnearly 40 per cent in a year and there were 657 in 2012.

The virus usually causes only relatively mild symptoms such as sickness, a temperature and muscle pain, which clear up by themselves within a month.

But it can be fatal for the elderly, cancer victims, pregnant women and others with existing liver problems.

Around one in 50 of those infected will die, rising to one in five pregnant women.

Experts say sausages have to be cooked at 70C (158F) for at least 20 minutes to kill the virus but they say that most Britons do not leave them in the oven for this long.

Tests have showed that it can survive at 60C (140F) after an hour.