The Dangers of Salmonella typhi

You may not be familiar with the bacteria called Salmonella typhi (S. typhi), but you probably have heard of typhoid fever. As the name of the disease implies, a high fever is the ‘signature’ symptom.

It is a bacterial disease that can easily occur when food or water supply become contaminated with this microorganism. It can easily spread from person to person, commonly from anyone who handles food (e.g. cooks/chefs, restaurant/kitchen workers, caregivers, etc.). This is especially true if food handlers start working after their symptoms have cleared as the bacteria remains active and is therefore transmissible to others.

Although the authorities require food workers to be vaccinated against typhoid (and to have their vaccinations updated every three years), quite a number slip through administrative cracks, for instance those operating small-scale food/drink businesses from home, as well as undocumented foreign workers.

About Salmonella

Salmonella is a pathogen that often causes food-related illnesses such as fever, headache, nausea, vomiting, intermittent constipation with diarhhoea and abdominal cramps. Most people refer to salmonella as food poisoning as the source of infection usually comes from food, with symptoms appearing within 12-72 hours.

Salmonella species food-poisoning (non-typhoid Salmonella) is seldom life-threatening for most healthy adults. However, children below five, the elderly, and people with weakened/compromised immune systems face a higher risk of more severe symptoms or developing complications.

S. typhi is more dangerous as it is infectious and can affect the entire body. During the incubation period, typhoid fever displays no signature signs/symptoms. Worse, signs/symptoms that appear later can be non-specific, making it easy to miss in the beginning.

As the disease progresses, some of the more common signs/symptoms include loss of appetite, feeling sick or unwell, having headaches and/or body aches, and possibly fever. Some people may develop a rash.

Leaving it untreated may lead to a high fever (up to 40°C or higher that may last up to three weeks), abdominal pain, intestine perforation, disseminated blood infection and can affect other organs. There is even a small chance (3-5%) that the patient becomes a carrier of typhoid .

How typhoid spreads

  • Unhygienic handling of food, especially if prepared by infected food handler may lead to contamination of food/drink.
  • Contamination of food/water sources from direct/indirect contact with an infected person’s faeces. Floods can further spread the disease.

Preventing typhoid fever

Typhoid fever can also happen in urban areas. There’s the abundance of roadside, tepi longkang and mamak stalls which many of us eat at or buy takeaways from without a second thought. It’s in our best interest not to assume that they are clean and hygienic, especially if they have no access to running water, making it challenging for the operator to maintain proper hand hygiene or general cleanliness.

Other known sources of contamination include shellfish, caught from polluted waters, that are undercooked or eaten raw (e.g. etak, cockles, kupang, clams, oyster), raw vegetables (lettuce, ulam), drinks and cold desserts prepared from unknown, contaminated water, and raw milk. Avoid eating raw vegetables/fruits and iced drinks – eat only thoroughly cooked food and drink only boiled or bottled water, especially during reported outbreaks. Hygiene is absolutely crucial, especially when it comes to food and drinks.

As an extra precaution, get vaccinated against typhoid fever if you live in, or plan to travel to, an area where typhoid is endemic, such as Kelantan (due to floods and poor rate of treated water usage), parts of northern/western Africa, most South Asian countries, parts of Indonesia and Peru . Regardless of the length of your stay, this advice applies, whether it is for a local family foodie adventure or an overseas trip.

An educational contribution by Malaysian Paediatric Association.

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