[Protecting Health During the Rainy Season①] Rainy Season Favorable for Bacterial Growth, 'Food Poisoning' Prevention Methods

Manage Hygiene and Be Cautious When Consuming 'Raw' Foods

Summer monsoon. [Image source=Yonhap News]

[Asia Economy Reporter Lee Gwan-joo] The monsoon season has officially arrived. This period poses many threats to health management. Frequent rain limits outdoor activities and exercise, and the high humidity makes it easy for various bacteria to proliferate. It is also a time when new diseases may emerge or existing conditions can worsen.

One of the most important illnesses to watch out for during the monsoon season is food poisoning. High temperature and humidity cause food to spoil easily, and the warm, humid weather accelerates bacterial growth. The reduction of ultraviolet rays from sunlight, which have a sterilizing effect, during the monsoon season also contributes to active bacterial activity. If flooding occurs in an area, the hygiene conditions worsen even more.

Food poisoning is a disease in which the digestive system becomes infected through the ingestion of contaminated food, causing acute or chronic symptoms such as stomach upset and diarrhea. Symptoms include fever, nausea, vomiting, diarrhea, abdominal pain, and rashes. Depending on the cause, it can be classified into bacterial food poisoning caused by bacteria, food poisoning caused by toxins produced by microorganisms in food, natural toxin food poisoning caused by animal or plant toxins, and chemical food poisoning caused by chemicals. Bacteria that cause bacterial food poisoning include Staphylococcus aureus, Salmonella, Shigella, and Vibrio parahaemolyticus. The risk of bacterial food poisoning is high during the hot summer and monsoon season.

Food and Drug Safety Ministry Food Poisoning Prevention Guidelines.

The symptoms appear fastest in food poisoning caused by Staphylococcus aureus. If you eat food contaminated with this bacteria's toxin, vomiting and diarrhea occur within 1 to 6 hours. In this case, it is better to use general treatments such as adequate hydration rather than taking antibiotics or antidiarrheal drugs.

If infected with typhoid fever, there is an incubation period of about 1 to 2 weeks, followed by high fever around 40 degrees Celsius, headache, and diarrhea. Early symptoms resemble a cold, including chills and aching joints in the head and limbs. In severe cases, complications such as intestinal bleeding and meningitis may occur. In Korea, 70-80% of cases are transmitted through contaminated water. To prevent typhoid fever, develop habits of boiling water and thoroughly cooking food. Getting vaccinated in advance is also recommended. People who have had typhoid fever in the past should especially wash their hands cleanly during the monsoon season and frequently disinfect kitchen cloths and cutting boards.

Salmonella is most commonly transmitted through poultry such as chickens and ducks. Eggs can also be a source of infection. Salmonella is vulnerable to heat and is killed by heating at 62-65 degrees Celsius for 30 minutes. Cooking eggs thoroughly can prevent infection, but secondary contamination from other foods during cooking can be problematic.

Shigella is transmitted through contaminated water and spoiled food such as feces and has strong infectivity. Shigella bacteria can survive in water for 2 to 6 weeks and in soil for several months. They are resistant to stomach acid and can cause shigellosis even if only a small amount is on the hands or if about 200 bacteria enter the body. Initial symptoms include nausea and vomiting, followed by several episodes of diarrhea per day for 3 to 6 weeks. Children and the elderly may experience dehydration and risk falling into a coma. Therefore, if diarrhea persists or dehydration symptoms appear, prompt hospital visits are necessary.

Vibrio sepsis is a frightening infectious disease with a mortality rate of over half of patients even with treatment. Vibrio bacteria, which live in seawater, multiply rapidly in summer when seawater temperature rises. Infection does not occur with just one or two bacteria entering the body; usually about 100,000 bacteria must invade to cause illness. In Korea, where hepatitis is prevalent, it mainly occurs in chronic hepatitis and cirrhosis patients who consume raw seafood such as sashimi or raw oysters. Over 90% of patients are men in their 40s and 50s. People with such underlying diseases must always eat cooked seafood.

Cholera is a representative infectious disease to be cautious of at the end of the monsoon season. Cholera is transmitted through feces, vomit, contaminated water, or food. It can be contracted by preparing food or eating with contaminated hands. After an incubation period of 2 to 4 days, severe diarrhea and dehydration symptoms causing thirst appear. Over time, blood pressure drops, skin turns bluish, and mental status becomes unstable. Strict hand hygiene, boiling food and water, disinfecting cooking utensils thoroughly, and not storing food for long periods?these four hygiene rules can prevent many cholera cases.

The shortcut to preventing food poisoning is to properly manage the selection, cooking, and storage of food. Bacteria mainly multiply between 0 and 60 degrees Celsius. Food should be stored below 4 degrees Celsius and heated above 60 degrees Celsius. Exceptionally, some bacterial toxins are heat-resistant and can cause food poisoning even when heated above 60 degrees Celsius. Toxins from Staphylococcus aureus, Bacillus, and Clostridium can proliferate even after heating. It is best to consume cooked food as soon as possible.

Thorough personal hygiene is also important. Washing hands is essential after going out, touching dirty things, or using the restroom. Also, people with hand wounds should not prepare food because they may be contaminated with Staphylococcus aureus. During the summer, when food poisoning incidents are frequent, it is important not to drink groundwater, mineral water, or well water. Unlike tap water, these are not chlorinated and may be contaminated with various food poisoning bacteria. (Advice from Professor Jeong Ji-won, Department of Infectious Diseases, Asan Medical Center, Seoul)