Microbial Contamination

What’s inside your Panipuri?

Suvecha Dahal, Senior Content Creator

October 12, 2017


Food can get microbial contamination anytime and anywhere – while it is being grown, processed, packaged, stored or made.



A typical roadside pani puri stall.

What is microbial contamination?

Microbes are universal and found everywhere. Some are harmless and some are harmful. All food you eat is prone to microbial contamination at every stage before being eaten. Contaminated food and water when ingested can cause food-borne diseases that can be toxic and infectious in nature. Most common include Staphylococcus and E. coli which can cause food poisoning, diarrhea, kidney failure and other infections. Others like Bacillus, Staphylococcus, Salmonella, Shigella, and Pseudomonas aeruginosa, can cause a host of illnesses.

Where do these microbes come from?

The microbes are either already in the food or added in through the environment during food processing or handling. The possibility of contamination from soil, air and water is very high, including human and animal waste. Hence hygiene of the farm, processing plant and food preparation area is very important. Also stale and improperly stored foods are highly susceptible to bear microbial contamination.

Sometimes the food is already contaminated, for example animal products like meat. When an animal shows slight sign of illness, they are immediately slaughtered and sent to market due to unethical processing practice. Instead of following a quarantine procedure and screening other animals, sick animals are immediately re-purposed and sent to the market to avoid losing money. Hence the adoption and regulation of good manufacturing practice is proving increasingly important.


Instead of following a quarantine procedure and screening other animals, sick animals are immediately repurposed and sent to the market to avoid losing money.


What kind of foods are prone to microbial contamination?

All kinds of food are prone to contamination depending on the way they are produced, processed, stored and handled. These are some major food groups that could be considered most likely for contamination.  

  • Processed food and street food:

The most contaminated food are those that require direct handling of the food by hand, for example street food. In one study, all tested street food items from an area in Kathmandu showed they carried some sort of bacterial contamination. Very few food handlers in Nepal receive training in hygiene and understand the source of contamination and the correlation between food handling and illness. Similarly, processed food on the shelves of grocery stores are prone to contamination too. As customers, we opt to equate attractive packaging with food quality. However, it is pertinent on adoption of good manufacturing and processing practices. Without it, there is high likelihood that the food was processed or manufactured in a subpar and unhygienic environment. Especially since there is low surveillance on food, diary and water industries, it poses serious threat to consumer health.

  • Fresh vegetables:

Fresh vegetables are prone to get easily contaminated from the soil it’s grown in, water and its environment. Fresh vegetables make a huge part of the Nepali diet. Fresh vegetables and foods that are eaten raw and without peeling gives a huge opportunity for parasitic transmission. That is why cleaning it using clean water thoroughly and properly is very important.


Fresh vegetables that are eaten raw or without peeling can lead to food borne illnesses

  • Water:

Although washing thoroughly can rid of microbial contamination to a certain extent, the interesting thing is that untreated and contaminated water could very well be the source of contamination. Also the water problems in the valley makes it difficult to maintain personal and commercial hygiene. Even bottled drinking water that are marketed as filtered and treated have microbial contamination. In a study, it was reported that among bottled drinking water that were tested 90% of samples showed microbial contamination above acceptable range.

Interestingly microbial contamination can also be present in herbal medicines. Many Nepalese consider ayurvedic medicines as better than allopathic medicines. But herbal medicines have a huge risk for contamination due to inappropriate storage, hygiene at ayurvedic clinics and minimum regulation. Herbal remedies could actually lead to serious health problems instead of relieving current ailments.

How does it affect my health?

Microbial contamination is a serious concern for public health. Food borne diarrheal illness kills more than 2 million people each year worldwide, especially children. Other conditions include typhoid, brucellosis, food poisoning, dysentery and diarrhea, even brain and neural disorders. Food borne illness continues to be the significant cause of morbidity and mortality in Nepal, especially with the proliferation of fast food cafes, restaurants and eating-out culture.
The situation is made worse by the increasing incidence of antibiotic resistance. The increasing incidence of antibiotics fed to animals which when becomes our food, leads to antibiotic resistance in our body over time. In the actual incidence of illness caused by microbial contamination, prescribed antibiotic medications do not work. Secondly the microbes in the food could be a resistant strain that does not respond to our immunity.


The increasing incidence of antibiotics fed to animals which when becomes our food, leads to antibiotic resistance in our body over time. In the actual incidence of illness caused by microbial contamination, prescribed antibiotic medications do not work.


What could be done?

It is important to ensure hygiene and cleanliness during the many stages of food processing and handling to prevent microbial contamination. Two most important concerns include:

  • Increased hygiene consciousness: Hygiene consciousness is not big in Nepal, not just with the food producers and handlers, but consumers as well. It may be due to lack of knowledge or negligence there is very little consumer motivation to seek confirmation that their food is treated with regulation. In recent past, there have been instances when food from popular restaurants were found to have faecal contamination . Even with such recorded evidence, the businesses still continue to get multitude of customers. With no pressure from the customers, there is no motivation for government to put regulations in place.
  • Good Manufacturing Practices: GMP is an approach that ensures that products produced are consistent in quality. Unhygienic and badly managed manufacturing and processing practice is rampant in Nepal. In a recent study, 43% of raw milk samples collected from milk collection centers were found to have microbial contamination. With the adoption and regulation of Good Manufacturing Practice and certification of businesses, the risk could be mitigated to a large extent.
  • Mandatory Food Testing: Food testing establishes the credency of the quality of your product. It is a great way to earn customer trust. While it might be an incredible undertaking for the government to establish mandatory and regular food testing right away, but it will be useful to set safety parameters for all types of food, water, diary, agricultural products.   

How can I make sure that my food at home is protected?

  • Wash thoroughly. Cook thoroughly.
  • Before handling food, while eating or cooking, wash your hands properly.
  • Store food in a cooler environment since high heat environment aides the growth of microbes.
  • Don’t drink water that you know is untreated or filtered.
  • Ensure that the water that you are using is pure and treated. Inquire about the quality of water that comes to your house.
  • Discard and do not consume food that shows any obvious  sign of deterioration or smell.

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