Summer Means Bacteria's Back

If you have been watching the local weather forecast lately, you may have noticed an unfamiliar index flashing across the TV screen along with the temperature and humidity indicators. Known somewhat ominously as the Food Poison Index, it predicts the possibility of a food poison outbreak on a scale of zero to 100.

If the index, released daily by the Korea Food and Drug Administration and the Korea Meteorological Administration, indicates a 10-35 reading, it means that a food poison outbreak is possible and calls for caution in food handling. At the other extreme, an index of 86 or higher means that food will turn bad within three to four hours of being left out unrefrigerated and that there is an elevated risk of a food poison outbreak.

Although the number of cases has been in decline over the past few years, food poisoning is still a major public health menace. There were 104 reported outbreaks of food poisoning involving 7,269 patients last year, according to the Korea Food and Drug Administration. While most healthy individuals do not develop a serious illness, food poisoning can be fatal in young children, the elderly and patients whose immune systems are compromised due to chronic illness.

The salmonella bacterium found in contaminated pork, deep-fried foods, kimbap, chicken and ham is the most frequent cause of food poisoning in Korea. The body usually recovers on its own after four to seven days, but severe diarrhea can require hospitalization.

Eating meat, dairy products or mayonnaise that has been contaminated with staphylococcus can also lead to food poisoning within a matter of hours, but bad side effects usually resolve themselves within a couple of days. "If you know that food may have been contaminated with the staphylococcus bacterium it should be discarded right away because the toxins released by the bacteria are not destroyed by heating," said Song In-sung, professor of internal medicine at Seoul National University.

In Korea, where people often enjoy raw fish, the vibrio vulnificus bacterium found in contaminated fish, shellfish and processed seafood poses a major health risk. Unseasonably warm coastal waters are thought to have contributed to the prevalence of vibrio vulnificus earlier than usual, prompting the National Health Institute to issue a vibrio septicemia warning last month. Vibrio septicemia － blood poisoning － is a potentially fatal disease that is contracted by eating contaminated raw seafood, and occurs commonly in the southwestern coastal areas of Korea. Ten of the 16 cases reported here last year resulted in death, and people with chronic liver diseases are particularly vulnerable. Vibrio gastroenteritis, characterized by diarrhea, vomiting and abdominal cramps, is also contracted by eating contaminated seafood.

Another bacterium, E. coli O-157, is found in contaminated meat, milk, cheese and alfalfa sprouts. While healthy individuals infected with E. coli O-157 do not usually experience serious illness, it is fatal in about 0.5 percent of patients.

All foods naturally contain small amounts of bacteria. It is when food is handled improperly that bacteria can multiply greatly to cause illness. Signs and symptoms of food poisoning vary with the source of contamination. Generally, diarrhea, nausea, abdominal pain and sometimes vomiting occur within hours of eating contaminated food. Mild to moderate illness often resolves itself, but you can help yourself recover by resting and drinking plenty of liquids. Anti-diarrheal medications are not recommended because they can slow the elimination of bacteria from your system.

The World Health Organization has issued what are known as the WHO Golden Rules for Safe Food Preparation that aim to reduce the risk of food-borne diseases. The guidelines recommend thorough cooking, meaning that the temperature of all parts of the food must reach at least 70 degrees centigrade. Frozen meat, fish and poultry must be thoroughly thawed in the refrigerator before cooking. Safe water is just as important for food preparation as for drinking. Boil water before adding it to food or making ice. Another common sense rule that people sometimes forget is to wash their hands not only before cooking but during food preparation as well.

After handling raw foods, wash your hands with soap before you start handling other foods.

If you cannot be persuaded to give up the raw fish habit even during hot-weather months, make sure to wash the seafood in running water and store it at a low temperature. Vibrio bacteria in contaminated fish and shellfish can be effectively removed when rinsed with fresh water, according to Lee Tae-shik, a researcher at the National Fisheries Research and Development Institute. Storing the seafood thus cleaned at a temperature of 10 degrees centigrade or lower was shown to significantly reduce the multiplication of the bacteria. "Since the bacteria are killed when heated to 70 degrees centigrade, it is advisable to eat cooked seafood," Mr. Lee said.

by Kim Hoo-ran