Stability and infectivity of enteroviruses on dry surfaces:Potential for indirect transmission control

Hand,foot,and mouth disease(HFMD)is a contagious disease mainly occurring in young children,and outbreaks commonly occur among young children in the Asia–Pacific region including Thailand.Moreover,the World Health Organization(WHO)monitors HFMD in the Western Pacific region to detect outbreaks and other significant events by the Regional Event Based Surveillance System.HFMD is mainly caused by a group of enteroviruses(EVs)transmitted through direct contact(person to person)and indirect contact with contaminated objects(surface-to-hand).However,few studies have examined the surface stability of EVs.In this study,we investigated the stability of enterovirus A71(EV-A71)and coxsackievirus A16(CVA16)on three different dry surfaces(wood,plastic,and stainless steel)using the endpoint titration using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide(MTT)staining of viable cells and real-time polymerase chain reaction(viral genome detection).The results revealed that virus infectivity dramatically decreased within a few hours on dry surfaces.However,viral RNA could be detected on dry surfaces for up to 28 days.Concerning heat inactivation,both EV-A71 and CVA16 were inactivated after exposure to 60°C for 15 min.Information on virus stability on different dry surfaces will provide useful information for HFMD transmission control.

The epidemiology of norovirus gastroenteritis in China:disease burden and distribution of genotypes

With the improvements of sanitation and nationwide safe water supply the occurrence of bacterial diarrhea declined remarkably,while viruses became the leading causes of acute gastroenteritis(AGE).Of these viruses,noroviruses(NoVs)are responsible for a considerable burden of gastroenteritis,especially in children<2 years and elderly≥65 years.NoVs circulating in the Chinese population are antigenically highly diverse with the genotype GII.4 being the dominant strain followed by GII.3.Given the widespread contamination in environmental sources,and highly infectious nature of NoVs,vaccination would be the desirable strategy for the control of NoV infections.However,a better understanding of acquired immunity after infection,and a reliable immunological surrogate marker are urgently needed,since two vaccine candidates based on virus-like particles(VLPs)are currently moving into clinical evaluations in China.

Cultural drivers and health-seeking behaviours that impact on the transmission of pig-associated zoonoses in Lao People’s Democratic Republic

Pig rearing is an important income source in the Lao People’s Democratic Republic(PDR),with many smallholder farmers using traditional free-range pig production systems.Despite the potentially significant health risks posed by pig production regarding pig-associated zoonoses,information on the sociocultural drivers of these zoonoses is significantly lacking.This review summarises the existing sociocultural knowledge on eight pig-associated zoonoses suspected to be endemic in Southeast Asia:brucellosis,Q fever(Coxiella burnetii),trichinellosis,hepatitis E virus,leptospirosis,Japanese encephalitis,Streptococcus suis and Taenia solium taeniasis-cysticercosis.It summarises current knowledge on these diseases grouped according to their clinical manifestations in humans to highlight the propensity for underreporting.A literature search was conducted across multiple databases for publications from 1990 to the present day related to the eight pig-associated zoonoses and the risk and impact connected with them,with Lao PDR as a case study.Many of these pig-associated zoonoses have similar presentations and are often diagnosed as clinical syndromes.Misdiagnosis and underreporting are,therefore,substantial and emphasise the need for more robust diagnostics and appropriate surveillance systems.While some reports exist in other countries in the region,information is significantly lacking in Lao PDR with existing information coming mainly from the capital,Vientiane.The disease burden imposed by these zoonoses is not only characterised by morbidity and mortality,but directly impacts on livelihoods through income reduction and production losses,and indirectly through treatment costs and lost work opportunities.Other factors crucial to understanding and controlling these diseases are the influence of ethnicity and culture on food-consumption practices,pig rearing and slaughter practices,hygiene and sanitation,health-seeking behaviours and,therefore,risk factors for disease transmission.Published information on the knowledge,attitudes and beliefs of people regarding pig zoonoses and their risk factors is also extremely limited in Lao PDR and the broader Southeast Asian region.The need for more transdisciplinary research,using a One Health approach,in order to understand the underlining social determinants of health and their impacts on health-seeking behaviours,disease transmission and,ultimately,disease reporting,cannot be more emphasized.