Research Publications (Food Safety)

Human noroviruses are recognized as the leading worldwide cause of sporadic and epidemic viral gastroenteritis, causing morbidity and mortality in impoverished developing countries and engendering enormous economic losses in developed countries. Transmitted faecal‐orally, either via person‐to‐person contact, or by consumption of contaminated foods or water, norovirus outbreaks are often reported in institutional settings or in the context of communal dining.

The role of animal feed as a vehicle for the transport and transmission of viral diseases was first identified during the porcine epidemic diarrhea virus (PEDV) epidemic in North America. Since that time, various feed additives have been evaluated at the laboratory level to measure their effect on viral viability and infectivity in contaminated feed using bioassay piglet models. While a valid first step, the conditions of these studies were not representative of commercial swine production.

Equine trypanosomosis comprises different parasitic diseases caused by protozoa of the subgenus Trypanozoon: Trypanosoma equiperdum (causative agent of dourine), Trypanosoma brucei (nagana) and Trypanosoma evansi (surra). Due to the absence of a vaccine and the lack of efficacy of the few available drugs, these diseases represent a major health and economic problem for international equine trade.

Significant global efforts have been directed towards understanding the epidemiology of highly pathogenic avian influenza (HPAI) across poultry production systems and in wild‐bird reservoirs, yet understanding of disease dynamics in the village poultry setting remains limited. This article provides a detailed account of the first laboratory‐confirmed outbreak of HPAI in the south‐eastern provinces of Lao PDR, which occurred in a village in Sekong Province in October 2018.

The protozoan Toxoplasma gondii is a causative agent of toxoplasmosis, an important and widespread zoonotic disease. The transmission of this disease in humans includes ingestion of sporulated oocysts present in contaminated water or food. T. gondii oocysts are widely distributed and toxoplasmosis is considered a major food and waterborne pathogen worldwide, making drinking water containing sporulated T. gondii oocysts a major source of contamination for people.

In recent years in China, clade 2.3.4.4 H5N6 plus clade 2.3.2.1 H5N1 subtype highly pathogenic avian influenza (HPAI) viruses have gradually become endemic in poultry, and their co‐circulation could inevitably facilitate the gene reassortment between each other.

Brucellosis is a widespread zoonotic disease with serious consequences on human and animal health. Brucella infections were reported in many terrestrial wild animals, from subtropical and temperate regions to arctic regions. In many areas, the epidemiology of brucellosis in wildlife is closely associated with the occurrence of the disease in livestock.

African swine fever (ASF) is a severe viral disease that affects both domestic and wild pigs and is responsible for major production and economic losses. As a transboundary animal disease (TAD) it can be spread by live or dead pigs and via pork products. Transmission can take place via contaminated feed and fomites including shoes, clothes, vehicles, knives and equipment. Unlike classical swine fever ASF does not have an approved vaccine (OIE, 2020).

In order to control Highly Pathogenic Avian Influenza (HPAI) H5N1 and Low Pathogenic Avian Influenza (LPAI) H9N2 virus spread in endemically infected countries, a detailed understanding of infection patterns is required. We conducted cross‐sectional studies in Bangladesh in 2016 and 2017, on 144 backyard, 106 broiler and 113 layer chicken farms. Although all sampled birds were negative for H5 virus by RT‐PCR, H5 antibodies were detected in unvaccinated birds on all three farming systems.

Environmental testing of poultry premises after an outbreak of an infectious disease like avian influenza (AI) or Newcastle disease, is essential to promptly verify virus‐free status and subsequently return to normal operations. In an attempt to establish an optimized sampling protocol a laboratory study simulating an AI virus contaminated poultry house with wire layer cages was conducted.

African swine fever (ASF) is currently considered the most significant global threat to pork production worldwide. Disease caused by the ASF virus (ASFV) results in high case fatality of pigs. Importantly, ASF is a trade‐limiting disease with substantial implications on both global pork and agricultural feed commodities. ASFV is transmissible through natural consumption of contaminated swine feed and is broadly stable across a wide range of commonly imported feed ingredients and conditions.

Comprehensive understanding of the patterns and drivers of avian influenza outbreaks is pivotal to inform surveillance systems and heighten nations’ ability to quickly detect and respond to the emergence of novel viruses. Starting in early 2017, the Italian poultry sector has been involved in the massive H5N8 highly pathogenic avian influenza epidemic that spread in the majority of the European countries in 2016/2017.

Although the unprecedented efforts the world has been taking to control the spread of the human coronavirus disease (COVID‐19) and its causative etiology [Severe Acute Respiratory Syndrome‐Coronavirus‐2 (SARS‐CoV‐2)], the number of confirmed cases has been increasing drastically. Therefore, there is an urgent need for devising more efficient preventive measures, to limit the spread of the infection until an effective treatment or vaccine is available.

Duck hepatitis A virus (DHAV) causes a highly contagious and acute disease in ducklings younger than 3 weeks of age and spreads rapidly by horizontal transmission to all susceptible ducklings in the flock. To date, there is no evidence of vertical transmission of DHAV‐1. In a previous study, we identified a novel DHAV type 1 (DHAV‐1) isolate that could infect adult ducks and induce laying drop.

Pre‐existing immunity against the conserved hemagglutinin (HA) stalk underlies the elicitation of cross‐group antibody induced by natural H7N9 virus infection and immunization in humans. However, whether broadly reactive antibodies can be induced by H7N9 infection and immunization in the absence of pre‐existing stalk‐specific immunity is unclear.

Migratory waterfowl, including geese and ducks, are indicated as the primary reservoir of avian influenza viruses (AIv) which can be subsequently spread to commercial poultry. The US Department of Agriculture's (USDA) surveillance efforts of waterfowl for AIv have been largely discontinued in the contiguous United States. Consequently, the use of technologies to identify areas of high waterfowl density and detect the presence of AIv in habitat such as wetlands has become imperative.

This study was carried out to investigate the frequency and genetic diversity of pestiviruses in abortion cases in cattle and small ruminants in Turkey. During January 2012 and December 2017, a total of 2029 aborted foetuses (553 bovine foetuses, 1388 sheep foetuses and 88 goat foetuses) were collected from different regions of Turkey. Real‐time RT‐PCR (RRT‐PCR) assays were used to detect pestiviral RNA in aborted foetuses.

Even though antimicrobial‐resistant bacteria have begun to be detected in wildlife, raising important issues related to their transmission and persistence of clinically important pathogens in the environment, little is known about the role of these bacteria on wildlife health, especially on endangered species.

Brucellosis is a common zoonotic disease caused by Brucella and is an epidemic worldwide. Currently, the most effective way to prevent and control the disease in animals is to use live, attenuated vaccines A19 strain. In China, the live attenuated Brucella abortus vaccine is widely used in animal immunization. To detect and confirm which vaccine strain caused the infection, we developed a new method to distinguish A19 strain from non‐A19 strains.

Highly Pathogenic Avian Influenza (HPAI) subtype H5N8 outbreaks occurred in poultry farms in France in 2016‐17, resulting in significant economic losses and disruption to the poultry industry. Current evidence on associations between actual on‐farm biosecurity risk factors and H5N8 occurrence is limited.

Poultry can become infected with avian influenza viruses (AIV) via (in) direct contact with infected wild birds. Free‐range chicken farms in the Netherlands were shown to have a higher risk for introduction of low pathogenic avian influenza (LPAI) virus than indoor chicken farms. Therefore, during outbreaks of highly pathogenic avian influenza (HPAI), free‐range layers are confined indoors as a risk mitigation measure.

Porcine sapelovirus (PSV) is a causative agent of acute diarrhea, pneumonia and reproductive disorders in swine. Since PSV infection interrupts the growth of other viruses due to its high replication capability in cell culture, the prevention of PSV replication is a keystone to the isolation of non‐PSV agents from PSV‐contaminated samples.

African swine fever (ASF) is an infectious disease of pigs and represents a massive threat to animal health and the pig industry worldwide. The ASF virus (ASFV) is efficiently transmitted via blood and meat from infected animals and can be highly stable in the environment. There is therefore great concern about the potential role of contaminated raw materials used for feed or bedding in the spread of ASFV.

Bacteriophage therapy is acknowledged as a potential tool to prevent or treat multidrug resistant bacterial infections. In this study, our major focus was on the bacteriolytic activity of phage EcSw (ΦEcSw) against the emergence of the clinically important Escherichia coli Sw1 and E. coli O157:H7. The amount of the antibiotics were changed in a concentration dependent manner and the ΦEcSw susceptibility to antibiotics were determined.

Avian coronaviruses, including infectious bronchitis virus (IBV) and turkey coronavirus (TCoV), are economically important viruses affecting poultry worldwide. IBV is responsible for causing severe losses to the commercial poultry sector globally. The objectives of this study were to identify the viruses that were causing outbreaks of severe respiratory disease in chickens in Trinidad and Tobago (T&T) and to characterize the strains.