Shigellosis is an acute, orally-infected bacterial enteritis (inflammation of the small intestine). It is spread world-wide and exists in Japan too. Many infected patients are those who have returned from developing countries.
The animals infected with shigellae are mainly humans and some primates. Since it is orally transferred from person to person via food and containers, infections are not rare within Japan, either. Epidemic outbreaks may occur due to contacts among concentrated groups of people, as may be found in facilities such as nursery schools, schools, welfare facilities, and lodging facilities.
Path of infection:
Shigella is extremely highly infectious, even through contact with very small amounts. This bacterium is discharged from humans through their feces. Infection occurs by the bacterium entering human bodies through the mouth (oral infection), and even through minimal contact with contaminated people’s hands, fingers, and/or food.
Food is a path of infection. Infections more often occur from food that is directly touched by hands (sushi, etc.). In addition, there are reported infections incurred through drinking raw water, and also infections of infants from putting toys and other goods in their mouths.
The incubation period is one to seven days (four days or less in many cases). The symptoms include: colitis (hemorrhagic inflammation of mucous membranes), fever, diarrhea, vomiting, stomachaches, tenesmus, and mucous and bloody stools.