High circulation of Hepatitis E virus in pigs and professionals exposed to pigs in Laos

Abstract

Epidemiological characteristics of hepatitis E Virus (HEV) differ due to the vast spatial heterogeneity in sanitation status, dietary habits and extent of exposure to animals. Although HEV infections are mostly asymptomatic, prognosis is poor for patients with compromised immune systems or pre-existing liver disease and during pregnancy. In developing countries, low hygienic standards and close human-animal interactions at farms and slaughterhouses likely favour zoonotic transmission of the virus. In this cross-sectional study from Lao People's Democratic Republic, anti-HEV IgG was detected by ELISA in 54.0% (136/252) of slaughter pigs, in 41.0% (57/139) of professionals exposed to pigs and in 18.1% of the nonrisk controls (38/210). We show that people occupationally exposed to pigs are at higher risk of infection (p < 0.001). In particular, contact to young piglets as compared to contact to the older slaughter pigs was a major risk factor (p = 0.011). Besides, consumption of bottled water significantly reduced the risk of infection (p = 0.018). In conclusion, we show that in Lao PDR, the high endemicity of HEV, the inadequate implementation of hygiene measures and the limited access to safe water jeopardize the health of professionals exposed to pigs.

Hepatitis B virus and other transfusion-transmissible infections in child blood recipients in Lao People’s Democratic Republic: a hospital-based study

“…Our previous studies found high anti-HEV seroprevalence in Lao adults-approximately 41% (57/139) in those who had and 18% (38/210) in those who had no contact with swine. 16 Although HEV can be transmitted through blood transfusion, 30 31 we did not find any increase in seroprevalence in the transfused group, suggesting that transmission of HEV via blood transfusion is either not very efficient 32 or not very common in Lao PDR.…”

“…In our previous studies in Lao PDR, we found significant HEV exposure and people in close contact with swine or cattle had higher anti-HEV seroprevalence in comparison with the general population. 16 17 In contrast, parvovirus B19, which is mostly transmitted through respiratory secretions and normally has a mild clinical presentation in children, does not appear to be widespread in Lao PDR, although there are limited data. 18 …”

Global infectious disease risks associated with occupational exposure among non-healthcare workers: a systematic review of the literature

“…Avian influenza virus Moderate poultry exposure (301-900 poultry-years) 21 Professional classification as a poultry seller 22 ≥10 years of occupational exposure 23 Another stall nearby, number of cages (more than five) 24 Workplaces near locations where H5N2 outbreaks in poultry were reported 25 Wholesale/retail live poultry markets 26 Female gender 22 23 Male gender 27 28 Coxiella burnetii Contact with small ruminants (sheep and goats) 29 Cattle contact at own or other farm 30 Keeping sheep or goats, exposure to arthropod bites 31 ≥3 daily goat-related tasks (milking, feeding, supply and removal, general animal healthcare and birth assistance), other goat breeds next to white dairy goat 32 Milking cattle, general healthcare of cattle, birth assistance, contact with raw milk, contact with cattle manure, contact with dead-born animals 33 Presence of cat(s) in goat stable, distance residence to nearest stable ≤10 m, distance to nearest positive farm 0-<4 km 28 Passed through the stores 34 Full working week, worked in cattle sector in the past 30 Age >50 years), rural area of residence, having little or no formal education 31 Lived as child on a ruminant farm, no farm boots for staff 32 Male gender 34 No respiratory protection mask 35 Living in rural areas 36 Hepatitis E virus Abattoir work, sewage work 37 Occupational contact with animals (forestry/pig farm workers) 38 Slaughterers 39 Exposure to soil, contact with swine 40 Having professions with exposure to pigs for more than 16.5 years 41 Unorganised swine farming 37 Woodcutting 42 Raw seafood processing 43 Feeding of pigs 44 Previous mission abroad (military forces) 45 Consumption of pork-liver sausages 37 Residence area 40 Age≥50 years, age group 25-34 years, ascending age, ages 40-49, 50-59, ≥60 and over 40 years 38 44 46-48 ≥7 working years ...…”

Recent Research on Occupational Animal Exposures and Health Risks: A Narrative Review

“…A study in Hubei, China, identified elevated seroprevalence among rabbit slaughterhouse workers compared with community controls and observed a doseresponse relationship between increasing seroprevalence associated with duration of employment [48]. Khounvisith and colleagues evaluated HEV seroprevalence among commercial pig workers in Laos, a region with HEV endemicity among swine [49]. The authors observed 41% of workers were HEV seroprevalent, compared with 18% of controls, and workers exposed to piglets during the growth process were at elevated risk.…”