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Over two-thirds of meat samples from HCMC were found to contain Salmonella bacteria, according to a new study by the Oxford University Clinical Research Unit (OUCRU).

Researchers purchased 117 samples of chicken meat, beef and pork from retail sites including supermarkets and wet markets across the city between October 2016 and March 2017. Eighty of those samples (68.4%) were found to contain non-typhoidal Salmonella.

“That’s not too different from previous studies published in international journals about Vietnam,” said Nguyen Thi Nhung, OUCRU microbiologist and first author of the study. “But it’s extremely high compared with the European Union,” she added.

Ms. Nhung pointed out that, from the European Union’s 2014 surveillance data, the prevalence of Salmonella in 25g meat samples was 2.26%, 0.62% and 0.23% for chicken, pork and beef. Respective figures in the OUCRU study, with sampling from HCMC, were 71.8% (chicken), 70.7% (pork) and 62.2% (beef).

If it is not cooked well, meat contaminated with Salmonella can cause gastroenteritis in humans. While most non-typhoidal Salmonella infections are self-limiting, some can turn severe depending on the number of Salmonella bacteria present.

“The high counts of Salmonella in some types of meat, especially chicken meat sold in wet markets, is worrying. We found that not only does the meat contain Salmonella – it contains a lot of Salmonella,” Ms. Nhung added. She found that there were about 1,500 Salmonella bacteria in each gram of meat from wet markets, and noted that more research is needed to understand the reasons for this high level.

OUCRU researchers also examined how resistant the Salmonella that was present in the meat samples was to antibiotics. The researchers grew the Salmonella isolates in the lab, and then exposed them to 32 different types of antibiotics. Up to 52.2% of Salmonella isolates were multidrug resistant, meaning they showed resistance to at least three antibiotic classes. The most commonly identified type of Salmonella was multidrug resistant Salmonella Kentucky ST198, with high levels of resistance against β-lactams and quinolones. One isolate from pork, in particular, proved resistant to colistin. It was the first time that bacteria resistant against colistin, a last-resort antibiotic, had been identified in meat in Vietnam.

People can become infected with these antibiotic-resistant bacteria when they handle raw meat or undercooked meat, eggs and vegetables. To avoid infection people should wash hands and prepare food well, including careful washing of raw vegetables.

OUCRU also worked with the National Institute of Veterinary Research and the Dong Thap Sub-Department of Livestock Production and Animal Health to conduct antibiotic residue screening.

Antibiotic residues in animal-derived foods such as meat, dairy and eggs may cause adverse health effects in the people who eat them, including allergic/toxic reactions, and upsetting the balance of normal healthy bacteria in the gut. They can also cause the emergence of antibiotic-resistant bacteria.

The research team tested a total of 357 meat samples (chicken, pork and beef) from wet markets and supermarkets from HCMC, Hanoi and Dong Thap.

They found antibiotic residues in 7.3% of samples, with wet market meat showing a higher prevalence (9.6%) than meat from supermarkets (2.6%). The difference between these two retail channels was statistically significant (p value of 0.016), showing the difference was not by chance.

Such results appear low compared with similar studies previously done in Vietnam, but antibiotic residue in meat is always considered unacceptable since it reflects non-compliance with antibiotic withdrawal periods.

Detailed results by OUCRU researchers and collaborators were published in a scientific publication of the International Journal of Food Microbiology.

This study was conducted as an extension of ViParc, a farm-based trial in Dong Thap from 2016-2020 aiming to help farmers in the Mekong Delta raise healthy chickens while using less antibiotics.

Would you take part in a clinical trial? Is it bad for your health? Or is it the safest way to get treated?

These are some of the questions Prof Jeremy Day will discuss on Thursday 11th January 2018, in his now sold-out session: “Clinical Trials – exploitation or essential health care?” as part of Science in the Cafe series.

The series is in partnership with The Old Compass Cafe and Bar, in Ho Chi Minh City.

Jeremy will explore issues around clinical trials including why we do them, how they work, and how do we interpret the results. He will use examples of clinical trials completed and underway here at Oxford University Clinical Research Unit in collaboration with local hospital partners.

Prof Jeremy Day is head of our CNS & HIV Infections Research Group, and a Professor of Infectious Diseases for the Centre for Tropical Medicine and Global Health  at the University of Oxford, U.K. He studied medicine and political philosophy at Cambridge University in the UK, and completed his specialist training in Infectious Diseases and General Internal Medicine in Edinburgh, London and Manchester in the United Kingdom, and Ho Chi Minh City in Vietnam. The CNS & HIV Infections Research Group study infections of the brain, often related to HIV, that are important problems in our local population. These diseases are usually also of wider relevance, throughout Asia and globally, and have high rates of death and disability.

Reducing antibiotic usage in poultry production starts with a commitment to good farming practices – show students participating in “Stop Your Poultry from Bingeing on Antibiotics,” a contest organized in the Mekong Delta province of Dong Thap from late 2017-early 2018.

“Only when a farmer is fully devoted to his/her chickens will he/she feel urged to apply good farming practices for the sake of preventing bacterial infections, of reducing the need to treat his flocks with antibiotics,” said Tran Thanh Nam, 17.

Nam is among the 123 students from Thanh Binh 1 and Chau Thanh 1 high schools to have proposed novel ways to communicate about antibiotic abuse in Vietnam – through photos, paintings and short essays.

In his artwork To Produce Truly Awesome Chickens, Nguyen Le Duy Thanh, 18, depicts how a farm is run like an “antibiotic binge-drinking party,” where chickens big and small alike get drunk on antibiotics and yet the owner still markets his chicken products as “clean.”

Another aspiring artist, Tran Le Huynh Thu, names her painting Let Me Tell You, Darling, in which a couple is discussing how to reduce antibiotic usage through such good farming practices as choosing strong chicken breeds and planning the right vaccinations. Ms. Thu, 18, believes that for any antibiotic reduction measure to work, farming couples should discuss more with each other, although sharing farming experience is uncommon among husbands and wives in rural Vietnam.

English_Top 10 entries from “Stop Your Poultry from Bingeing on Antibiotics” contest

Together the contest participants brought antibiotic abuse into the perspective of complex societal relations. And they did that, not without a sense of humor.

With 10 prizes, “Stop Your Poultry from Bingeing on Antibiotics” will have its award ceremonies in Thanh Binh and Chau Thanh districts on the 8^th and 9^th January respectively.

It is organized by the Ho Chi Minh City-based Oxford University Clinical Research Unit, in collaboration with the Dong Thap Center for Health Information and Education, and the Provincial Department of Education and Training.

“Stop Your Poultry from Bingeing on Antibiotics” is a community-engagement activity under ViParc, a research project aiming to help farmers in the Mekong Delta raise healthy chickens with lesser amounts of antibiotics.

The ViParc project is conducted against the backdrop of widespread antibiotic overuse and misuse in Vietnam’s farming sector, which is believed to be a major driver of antibiotic resistance. Such resistance refers to the ability of bacteria to avoid the mechanism of action of antibiotics, resulting in failure in the treatment of bacterial infections in both animals and humans.

ViParc researchers recently confirmed the presence of colistin-resistant non-typhoidal Salmonella in pork purchased from a wet market in Ho Chi Minh City. It was the first time that bacteria resistant against colistin, a last-resort antibiotic, had been identified in meat in Vietnam.

In a new paper published in PNAS, OUCRU researcher Lauren Carrington has provided evidence supporting the introduction of Wolbachia into areas where there are dengue virus-transmitting mosquitoes, as a biocontrol method to reduce the transmission of dengue and other arboviruses.

Wolbachia is a bacteria that manipulates its host reproductive system to enhance its spread through a population. In doing so however, it can also provide its host with other benefits, like protection from virus infections. When Aedes aegypti, the primary mosquito vector of dengue virus around the world, is infected with a strain of Wolbachia called wMel and then exposed to dengue virus, fewer mosquitoes will eventually become infected with the virus. The World Mosquito Program has been working with Wolbachia-infected Aedes aegypti for a number of years under laboratory conditions, and accumulated evidence that supports Wolbachia’s ability to reduce dengue virus transmission in the field.

This study is special though, because it directly tested whether Wolbachia would be effective at blocking dengue virus transmission from humans to mosquitoes, not just in the lab environment, but in natural conditions in the real world. To do this, Dr Carrington and colleagues collected mosquito eggs and larvae from the wild in two field sites: Nha Trang city, which was Wolbachia-free, and Tri Nguyen, a village on Hon Mieu Island (off the coast of Nha Trang). Hon Mieu is the site of Wolbachia releases for the World Mosquito Program in Vietnam. The eggs were brought back to the lab and reared under standard, optimal conditions. The oldest of the larvae that were collected, were brought back to the lab, just in time for emergence as adults. Field reared and lab-reared females were then directly fed from the blood of human dengue patients.

The team observed that, as expected, the Wolbachia-infected mosquitoes had overall reduced odds of developing a dengue virus infection in the abdomen and saliva than mosquitoes that were not infected with Wolbachia, under both field- and lab-rearing conditions. However, when wild type and Wolbachia-infected mosquitoes were reared under field conditions, the relative difference between the two groups was greater than when they were reared under laboratory conditions. This shows that lab-rearing conditions underestimate the positive effect that Wolbachia can have on preventing transmission of the dengue virus from mosquitos to humans.  Dr Carrington explained, “Our study shows that infecting mosquitos with Wolbachia is an effective way to block dengue virus transmission from humans to mosquitoes  – and the effect is even greater in the wild than in the lab”.

Every year thousands of pilgrims visit religious sites in the mountains of Nepal.  Many of these local pilgrims are unaware of the dangers of climbing to high altitudes and many succumb to altitude related illnesses.  Some even die on the mountains.  The Himalayan Rescue Association, OUCRU Public Engagement and Media for Development worked together with the pilgrim community to create a public health film to inform others of the challenges of these journeys.

https://www.youtube.com/watch?v=Mw2ZHrAkGVc

In August 2016 MFD worked with 12 young people from Bhaktapur in Kathmandu to film the Gosainkunda pilgrimage.  The Gosainkunda Lake lies at an altitude of 4380 meters above sea level and is considered holy by Buddhist and Hindus in Nepal. A festival lasting two to three days takes place here every year and is attended by up to 20,000 pilgrims. A desolate place for most times of the year, it becomes a teeming hub where pilgrims from right across the country gather to bathe and pray at the lake.  Many pilgrims are ill prepared, ascend too quickly and suffer from altitude related illnesses.

Filming their own experiences and interviewing others on the pilgrimage or at the local rest stops, the group created a film which explains the perils of the mountains and how to be better prepared.  In 2017, HRA, MFD and some of the participants toured around Kathmandu holding community screenings of the film and offering advice to those considering the pilgrimage.

This project was led by Dinesh Deokota (MFD), Dr Buddha Basynat (OUCRU-NP and HRA) and Mary Chambers (Head of PE OUCRU).  The project was funded by a Wellcome Trust International Engagement Award.