Non-typhoidal Salmonella (NTS) infection |
Responsible for ~0–7% of diarrhoea in <5 year children; limited data on serovar distribution in humans. High levels of NTS carriage among adults; some evidence for person-to-person transmission among children |
High prevalence and variability of serovars in poultry, pigs, fish/seafood and meat products |
Meeting export targets of meat products will require improved control of NTS in fish, pigs and poultry |
Attribution studies in humans; impact of urbanization and backyard farming on human immunity; Antimicrobial resistance; NTS diversity within backyard versus industrialized production systems |
Campylobacter spp. infection |
Responsible for ~4–40% of diarrhoeal cases in <5 year children (Red River Delta) |
Very high prevalence in chicken carcasses and meat products |
High levels of multi-resistance including ciprofloxacin resistance |
Risk factors and attribution studies among clinical cases; prevalence and genetic diversity in backyard versus industrialized production systems, and along processing/ retailing market chains; impact of urbanization and backyard farming on human immunity |
Streptococcus suis infection |
Most common cause of adult bacterial meningitis; majority of cases caused by S. suis serotype 2; approximately 5–43 confirmed cases per year in Vietnam |
High (>40%) carriage in upper respiratory tract (tonsils) of market weight swine; predominance of S. suis 2; epidemiological interactions with viral infections (e.g. PRRSv) |
Improved control over illegal marketing of ill pigs; hygiene and health quality standards in slaughter/processing facilities |
Estimation of burden of disease using combined indicators for human morbidity/mortality and economic losses to swine sector; risk factors for pig colonization; development of porcine vaccines and novel diagnostic tools for herd management and risk mitigation |
Listeriosis |
Three clinical case reported from north Vietnam with meningitis in 2008/2009 |
No data |
Possible increased incidence in coming years, due to greater consumption of packed food items including soft cheeses, meat and fish |
Consumer perceptions of risk, health and safety in relation to highly processed foods; enhanced surveillance among high risk groups; investigation in food processing plants |
Toxoplasmosis |
No published data on human clinical cases. Seroprevalence in humans ranging between 1.1 and 6.4%. Higher (7.7–11%) among pregnant women and drug users in some |
Very high prevalence in domestic dogs and pigs (>50%); lower in cattle and buffalo (3–10%) |
Unknown risks due to poor understanding of principle zoonotic reservoir |
Enhanced surveillance among pregnant women and neonates to estimate burden of disease; prevalence of oocysts in cats, dogs, dog meat and treated and untreated wastewater |
Cryptosporidiosis |
No published data on human clinical cases. At least two studies of paediatric diarrhoea failed to identify Cryptosporidium
|
High prevalence of C. parvum and C andersoni in cattle; Cryptosporidirum spp. oocysts found in pigs and farmed fish but not speciated |
Risks associated with uncontrolled urbanization, peri-urban agriculture, waste water treatment and climate change |
Etiological and syndromic studies of enteric disease in humans and animals; development of informal networks for reporting and investigating suspect foodborne outbreaks |
Giardiasis |
No published data on human clinical cases. 4% carriage of G. lamblia among healthy subjects in north Vietnam |
50% of calves near Hanoi found positive by feacal microscopy; however, dominant species may be non-zoonotic G. duodenalis
|
Risks associated with uncontrolled urbanization, peri-urban agriculture, waste water treatment and climate change |
Etiological and syndromic studies of enteric disease; species diversity in farm animals and farmed ’wild’ exotic species; risk factor studies; detection of oocysts in vegetables, treated and untreated wastewater |
Taeniasis/ cysticercosis |
In the late 1990s, approximately 100–150 cases/year with cerebral cysticercosis in northern Vietnam. Human surveys (2003/2004) using stool egg counts suggest low level prevalence of (0.2–7.2%). Likely to be circumscribed to certain areas in Vietnam |
Multiple species identified from pigs and domestic dogs, including T. solium, T saginata asiatica
|
Probable future reductions in prevalence/incidence due to changes in swine production |
Seroepidemiological and clinical studies. Identify host species of T. s. asiatica; studies investigating prevalence of Taenia eggs in the environment |
Fascioliasis |
>1,000 patients/year reported in central provinces, especially Quang Nai; seroprevalence ~8% in some areas; diagnostic case reports increasing |
Hyper-endemic in ruminants of central provinces (>70% in adult cattle); high level species diversity; hybrid species identified (F. gigantica and F. hepatica) |
Risks associated with changes in forage production for beef and dairy cattle |
Detection of metacercariae in leaf vegetables; ecologic determinants of disease transmission; risk assessment; development of novel indicators to estimate combined disease burden in humans and animals |
Leptospirosis |
Highly seroprevalence in southern Vietnam suggesting endemicity. Responsible for 2–8% cases of acute jaundice. Main serovars identified Seramanga and Bataviae |
Hyper-endemic in pigs in the Mekong Delta |
Very common in kidneys in fattening pigs. Main serovars Bratislava, Iterohaemorrhagiae, Automnalis and Pomona |
Estimate burden of infection by targeting patients with suspect hepatic and haemorrhagic syndromes. Investigate main reservoirs of infection including rats, pigs, dogs and cattle |
Trichinellosis |
Decreasing incidence in recent years; small outbreaks in northwest |
Seroprevalence in swine ~14–20% in some areas |
Probable future reductions in prevalence/incidence due to changes in swine production |
Role of rodents in transmission; risks associated with specific culinary practice |
Fishborne zoonotic trematode (FZT) infection |
High rates of asymptomatic carriage in humans living in Red River Delta provinces (>75%) |
High species diversity including both pathogenic and non-pathogenic flukes of multiple genera |
Risks associated with expansion of aquaculture industry, waste water treatment and climate change |
Enhanced surveillance to estimate disease burden; detection of FZT in fish; risk assessment; intervention studies; ecologic determinants of disease transmission |