Another case of a rare type of salmonella has been identified in Otago and Southland this week, but health authorities have yet to establish the cause of the infection.
The new case brings to 11 the number of Otago-Southland people to have the illness since October 13, about a-quarter of the total cases throughout the country.
Nine of the cases have been in Otago and two in Southland. Most of the 40 cases of salmonella Typhimurium phage type 42 found have been from the South Island, with only six cases identified in the North Island.
Public Health South medical officer of health Dr Marion Poore said initial investigations had not given any definitive source of infection.
The Ministry of Health, the Institute of Environmental and Scientific Research and public health services have begun a case control investigation.
Dr Poore said this involved labour-intensive work, looking at each case and comparing it with cases of people with similar characteristics who did not have the illness.
Staff were making a big effort to get the work completed before Christmas.
Dr Poore agreed because the severity of the symptoms of the illness can vary from person to person, it was " entirely possible" there were more cases which had not been identified.
Some people would suffer relatively minor effects which would not prompt them to visit a doctor and be tested for the illness.
Symptoms include muscle aches, headache, diarrhea and vomiting which may be so severe in some patients they become dehydrated. The illness usually lasts several days.
Salmonella
Preventing salmonella transmission and infection
• Food handlers with salmonella infection and diarrhea and/or vomiting should stay away from work until the infection has cleared.
• Anyone with gastroenteritis should avoid preparing meals for others. If you must do so, care should be taken to ensure proper hand washing and to follow the four Cs - clean, cook, cover, chill.
• Salmonella thrives at room temperature. Food should be cooked thoroughly and then kept very cold or very hot.
• Wash hands after using the toilet (remember the 20+20 rule: 20 seconds to wash, plus 20 to dry on a clean towel or paper towels).
• Salmonella can be easily passed from person to person and particular care with personal hygiene needs to be taken around infants with diarrhea.
