Sothyra Tum

Sothyra Tum

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Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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4 May 2021 in Pathogens
Verified
Journal Article
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Rortana CheaRortana Chea
Rortana Chea
HNHung Nguyen-Viet
Hung Nguyen-Viet
STSothyra Tum
Sothyra Tum
FUFred Unger
Fred Unger
SBSofia Anna Boqvist
Sofia Anna Boqvist
Johanna LindahlJohanna Lindahl
Johanna Lindahl
Salmonella spp. and Staphylococcus aureus are two of the most common foodborne bacteria in animal-source foods (ASF) that cause illness worldwide. This study aimed to determine the prevalence of Salmonella spp. and S. aureus in chicken meat and pork in markets in Cambodia. Sampling was done in 52 traditional markets and 6 supermarkets in 25 provinces of Cambodia between October 2018 and August 2019. In total, 532 samples were obtained: chicken meat and pork (n = 408, 204 of each), chicken and pork cutting board swabs (n = 124, 62 of each). All samples were analyzed for the presence of Salmonella spp. and S. aureus; colony-forming units per gram (CFU/g) of coagulase-positive Staphylococci (CPS) were counted, and a subset of samples was also analyzed for the most probable number (MPN, n = 136) of Salmonella. The overall prevalence of Salmonella spp. and S. aureus were 42.1% (224/532) and 29.1% (155/532), respectively, with 14.7% (78/532) of samples containing both bacteria. The prevalence of Salmonella spp. in chicken meat was 42.6%, on chicken cutting board it was 41.9%, on pork it was 45.1%, and the pork cutting board 30.6%. Chicken meat had a significantly (p-value < 0.05) higher prevalence of S. aureus, 38.2%, compared to the chicken cutting board, 17.7%, pork 28.9%, and pork cutting board 11.3%. Mean MPN-Salmonella was 10.6 MPN/g in chicken and 11.1 MPN/g in pork samples. Average Log CFU/g of CPS in chicken and pork samples were 2.6 and 2.5, respectively. The results indicate that chicken meat and pork in Cambodia were highly contaminated with Salmonella spp. and S. aureus, posing risks to consumers’ health. Urgent interventions are necessary to improve hygiene for safer meat in Cambodian markets.

1 September 2020 in Pathogens
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HLHéléna Ladreyt
Héléna Ladreyt
HAHeidi Auerswald
Heidi Auerswald
STSothyra Tum
Sothyra Tum
SKSreymom Ken
Sreymom Ken
LHLeangyi HENG
Leangyi HENG
CVChevalier Veronique
Chevalier Veronique
Japanese encephalitis virus (JEV) is the main cause of human viral encephalitis in Asia, with a mortality rate reaching 30%, mostly affecting children. The traditionally described cycle involving wild birds as reservoirs, pigs as amplifying hosts and Culex mosquitoes as vectors is questioned, with increasing evidence of a more complex multi-host system involved in areas where densities of pigs are low, such as in Cambodia. In 2018, we examined pigs, chickens, ducks and dogs from Kandal province, Cambodia, for antibody response against JEV by hemagglutination inhibition and virus neutralization assays. Forces of infection (FOI) for flaviviruses and JEV were estimated per species and per unit of body surface area (BSA). JEV seroprevalence reached 31% (95% CI: 23–41%) in pigs, 1% (95% CI: 0.1–3%) in chickens, 12% (95% CI: 7–19%) in ducks and 35% (95% CI: 28–42%) in dogs. Pigs were most likely to be infected (FOI: 0.09 per month), but the FOI was higher in ducks than in pigs for a given BSA (ratio of 0.13). Dogs had a lower FOI than ducks but a higher FOI than chickens (0.01 per month). For a given BSA, dogs were less likely to be infected than pigs (ratio of 1.9). In Cambodia, the virus may be circulating between multiple hosts. Dogs live in close contact with humans, and estimating their exposure to JEV infection could be a relevant indicator of the risk for humans to get infected, which is poorly known due to underdiagnosis. Understanding the JEV cycle and developing tools to quantify the exposure of humans is essential to adapt and support control measures for this vaccine-preventable disease.

10 May 2021 in Pathogens
Verified
Journal Article
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EHEllinor Henriksson
Ellinor Henriksson
RSRebecca Söderberg
Rebecca Söderberg
GHGunilla Ström Hallenberg
Gunilla Ström Hallenberg
Kroesna KangKroesna Kang
Kroesna Kang
Sokong LySokong Ly
Sokong Ly
Johanna LindahlJohanna Lindahl
Johanna Lindahl
Japanese encephalitis (JE) is endemic in Cambodia, but circulation of JE virus (JEV) among domestic pigs has previously only been studied in the southern part of the country. The main purpose of this study was to determine the seroprevalence of JEV antibodies in smallholder pigs held in rural areas of Kampong Thom, Preah Vihear, Ratanakiri, and Stung Treng provinces, northeastern Cambodia. Another purpose was to identify possible associations between serologic status and other factors, such as reproductive disorders, and to investigate the farmers’ knowledge of mosquito-borne diseases and use of preventive measures. In October 2019, 139 households were visited throughout the study area, and 242 pigs were sampled for blood. The sera were analysed with ELISA for JEV antibodies. Household representatives were interviewed, and data were recorded for each sampled pig. The apparent seroprevalence was 89.1% in pigs between 3 and 6 months of age, and 100% in pigs over 6 months of age. In total, 93.0% of the pigs tested positive. Province appeared to be the only factor significantly associated with serologic status (p < 0.001). Almost all (97.8%) respondents knew that mosquitos could transmit diseases, and 70.5% had heard of JE. However, only one respondent knew that JEV is transmitted to people through mosquito bites. Very few respondents knew that pigs can become infected with JEV, and no one knew that mosquitos transmit the virus. All families used some sort of mosquito protection for themselves, but only 15.1% protected their pigs from mosquito bites. The children were vaccinated against JE in 93 households, while adults only were vaccinated in eight households. The results suggest that JEV transmission is intense in northeastern Cambodia, and that people’s knowledge about the transmission route of JEV and the role of pigs in the transmission cycle is low. Fortunately, people are well aware of mosquito-borne diseases in general and use mosquito protection, and many children are vaccinated against JE. Nonetheless, it is important that national vaccination is continued, and that people—especially in rural areas where pigs are commonly kept—are educated on the ecology and transmission of JEV.

24 January 2015 in Tropical Animal Health and Production
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STSothyra Tum
Sothyra Tum
IRIan Robertson
Ian Robertson
JEJohn Edwards
John Edwards
RARonello Abila
Ronello Abila
SMSubhash Morzaria
Subhash Morzaria

1 September 2019 in Veterinary Parasitology
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Journal Article
Closed access
VLVandara Loeurng
Vandara Loeurng
MIMadoka Ichikawa-Seki
Madoka Ichikawa-Seki
AWAnchalee Wannasan
Anchalee Wannasan
STSothyra Tum
Sothyra Tum
WCWarangkhana Chaisowwong
Warangkhana Chaisowwong
Saruda TiwananthagornSaruda Tiwananthagorn
Saruda Tiwananthagorn

Verified
Journal Article
Open access
PDF file
RSRebecca Söderberg
Rebecca Söderberg
Johanna LindahlJohanna Lindahl
Johanna Lindahl
EHEllinor Henriksson
Ellinor Henriksson
Kroesna KangKroesna Kang
Kroesna Kang
Sokong LySokong Ly
Sokong Ly
GHGunilla Ström Hallenberg
Gunilla Ström Hallenberg
Cysticercosis and Trichinella spp. infection are parasitic zoonoses prevalent among pigs in Southeast Asia, where pork is the most important source of meat. In rural Cambodia, many pigs are raised extensively in family backyards, and information regarding the prevalence in rural small-scale pig production is very limited. This study was conducted in four provinces in north-eastern Cambodia to determine the seroprevalence of porcine cysticercosis and Trichinella spp. infection in rural villages, and to identify possible risk factors. Only households with less than 10 pigs above three months old were eligible. In total, 139 households participated, and 242 blood samples were collected. Farmers were interviewed about food and hygiene habits, disease knowledge and practices. The serum samples were analysed by ELISA to determine antigens to Taenia spp. cysticerci or antibodies to Trichinella spp. muscle larvae. Positivity among the pigs was 11.2% (95% CI 7.5–15.8) for Taenia spp. cysts and 2.5% (95% CI 0.9–5.4) for Trichinella spp. Cysticerci were more common in the province Preah Vihear (p < 0.001) than in the other provinces. Risk factors associated with porcine cysticercosis were management systems for the pigs and access to human faeces (p < 0.001). Trichinella spp. infection in pigs was more common in the province Ratanakiri (p = 0.001). The main risk factor associated with Trichinella spp. transmission was feeding pigs with food waste (p = 0.048). More men had heard about cysticercosis than women (p = 0.002), and men also consumed undercooked pork meat to a greater extent (p = 0.004). Although the present study is relatively small, several risk factors could be identified for porcine infection with Taenia spp. and Trichinella spp., which can be used to guide future interventions to improve both porcine and human health in these provinces.