Don't celebrate your street food resistance just yet

A study conducted by Dhaka University's Centre for Advanced Research in Sciences (CARS) has uncovered alarming levels of harmful bacteria present in popular street foods widely sold across Dhaka.

According to the study, each plate of chotpoti on average was found to contain 7.2 crore E. coli, 750 Salmonella, and 750 Vibrio bacteria. Similarly, chickpea mix, sandwiches, sugarcane juice, aloe vera juice, and mixed salads were also contaminated with significant amounts of these bacteria.

For those unfamiliar, some variants of E. coli, Salmonella, and Vibrio bacteria are known for causing diarrheal diseases by producing toxins that damage the intestinal lining, leading to symptoms such as watery or bloody diarrhoea.

But what's astonishing about the recent study is that despite the high presence of harmful bacteria in street foods, most people who consume them aren't falling ill.

As per the research project titled 'Prevalence of Microbial Hazards in Street Food and Ready-to-Eat Salad Items in Restaurants and Their Probable Risk Analysis', funded by the Bangladesh Food Safety Authority (BFSA), out of every 10,000 consumers, only two might get sick due to E. coli, four due to Salmonella, and just one due to Vibrio.

This news was greeted joyously by a large section of people as soon as the findings of the study started making rounds in the media. If people are indeed not falling sick, does it mean you can continue to eat street food?  In that case, what are the implications of the study?

Photo: TBS

In a bid to clear the confusion, we reached out to Dr Md Latiful Bari, the lead investigator of the study. He is also the Chief Scientist and Head of Food, Nutrition and Agriculture Research Laboratory at the CARS. 

Through our conversation with him, it became apparent that the issue is not only more complex than initially perceived, but it is also more serious than has been portrayed in the local media. 

To start with, while the immediate effects may not be evident, we shouldn't ignore the long-term health consequences of consuming contaminated foods.

One straightforward reason why fewer people might get sick despite consuming these foods is that over the years, the residents of the city have been exposed to these bacteria to such an extent that they have developed a substantial degree of immunity, which helps prevent diarrheal diseases to a large extent.

In fact, the fewer instances of illness people experience from consuming such foods, the more likely it is that they have consumed them over the years and developed immunity to potential risks.

"When your body is faced with contaminated food frequently, it adapts to it. So, while a foreigner might easily fall ill from consuming these street foods, we, who are accustomed to them, are less likely to," explained Dr Bari.

But there is hardly any reason to rejoice this information. 

Even if it temporarily looks like the immune system has become more efficient at recognising and fighting off these bacteria, reducing the likelihood of falling ill, "ultimately there is a high chance of chronic diarrhoea, which will be extremely challenging to treat," warned Dr Bari. 

There are compelling reasons to support this notion. Frequent consumption of foods contaminated with high levels of bacteria can have long-term consequences for gastrointestinal health, according to a Crohn's & Colitis Foundation literature review.

For instance, continuous exposure to bacterial toxins and pathogens in contaminated foods can lead to chronic inflammation in the gastrointestinal tract, increasing the risk of various diseases like inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS).

These foods may also disrupt the balance of bacteria in the gut microbiome. This imbalance, known as dysbiosis, can compromise digestive health and increase susceptibility to gastrointestinal disorders such as diarrhoea, constipation, and gastrointestinal infections.

Even more concerning is that some bacteria present in the street foods are antibiotic resistant, meaning they can contribute to the spread of antibiotic resistance within the gut microbiome.

According to Global Research on Antimicrobial Resistance, E. coli and Salmonella Typhi are among the top five pathogens to be aware of in Bangladesh, as they caused the most number of deaths associated with antimicrobial resistance (AMR) in 2019.  

"This is a matter that we cannot afford to overlook,"  Dr Bari said. 

He pointed out that many people in Bangladesh have already developed resistance to seven or eight different types of antibiotics.

"By the time today's youth, who are regularly consuming contaminated foods, reach old age, there may be only two or three types of antibiotics left effective for them," Dr Bari said. 

This implies that despite ongoing advancements in medical science, many people in our country won't be able to benefit from it. They may easily succumb to illnesses due to a compromised disease prevention system.

For context, the World Health Organization (WHO) has identified Bangladesh as one of the countries with a high burden of AMR. 

According to the WHO's Tripartite AMR Country Self-Assessment Survey (TrACSS) Report 2021-22, in 2019, there were 26,200 deaths attributable to AMR and 98,800 deaths associated with AMR in the country.

The number of AMR deaths in Bangladesh surpasses the deaths from chronic respiratory diseases, respiratory infections and tuberculosis, maternal and neonatal disorders, diabetes and kidney diseases, and digestive diseases.

So, Dr Bari emphasised identifying key reasons behind bacteria-contaminated street food in Dhaka and taking adequate steps to mitigate them. He also believes that regardless of the study outcomes, Bangladeshi people will not stop eating street food.

Photo: TBS

From what he learnt from the study, limited access to safe water inhibits street food vendors from maintaining proper hygiene and sanitation practices, including food preparation techniques, utensil handling, personal cleanliness, and food storage methods throughout the day. 

He recommended that street food corners can be established throughout the city with adequate supply of water and other utility services. 

"Such centres will provide an environment for storing, preparing and serving safe food as well as ensure compliance with hygiene standards," he said.

A lack of education and awareness about cleanliness and food safety also leads to the production of food in unhygienic conditions. 

According to Dr Bari, street food vendors and restaurant staff must receive training on proper food handling, hygiene, and sanitation practices to reduce the risk of microbial contamination.

Jannatul Naym Pieal, Sketch: TBS

Lastly, he also felt that the absence of licensing for street food vendors complicates matters. 

"Given that street food vendors operate without a licence, it's crucial to provide them with clear legal standing so they can collect their entitlements and sustain their livelihood," he concluded.