Detective goes to work within the body

Press, 18 July 1985, Page 17

Detective goes to work within the body

By

DENIS DWYER,

information

officer, Canterbury Hospital Board

Examinations for parasites in human blood and intestines have increased considerably in Christchurch in recent years. Each month this year the microbiology department of Christchurch Hospital has received an average of 100 requests for these examinations.

the increase is due to several factors, including probably greater parasitic infection in the population as a result of rapid and more frequent travel, sexual permissiveness, and immigration from Third World countries.

One of the parasitic infections increasingly diagnosed in Christchurch in recent years is malaria. Indeed, the resurgence of malaria is causing world-wide concern. At Christchurch Hospital, 37 cases were diagnosed from January, 1 J978, to December, 7/983. Fifteen of

these infections were acquired in Papua New Guinea and 21 cases irom other countries; one was unknown, because the person had travelled in many different areas of potential malarial infection.

Happily, from the 1970 s there has been a big improvement locally in the knowledge and skills of parasitology. A locally trained medical technologist in the department, Mr Graeme Paltridge, spent a period in Vietnam with the New Zealand surgical team and developed there an interest in ogyFrustrated by the lack of knowledge in New Zealand of human parasitology, he studied in 1980 at the Centre for Disease Control, Atlanta, Georgia, and visited the parasitology departments of the U.C.L.A. , t

On return to New Zealand he implemented some new diagnostic techniques and taught others to find organisms that had never been found here before. “There are some parasites, particularly the protozoa, which are quite common overseas,” says Graeme Paltridge, “and we are now finding them as .endemic in New Zealand.” An example is an amoeba-like organism, Dientamoeba fragilis, possibly transmitted by the common pinworm. It is a significant cause of chronic bowel discomfort and diarrhoea, especially in children. is a more re-

cently discovered parasite. It causes diarrhoea and severe pathological lesions in the intestines of calves, lambs, foals, pigs, deer, and other animals. Chronic Cryptosporidium infection has been associated with patients with A.I.D.S. and it is being recognised as a cause of acute gastroenteritis among the population in general. Along with the transmission of parasites internationally, there has been an increasing awareness of parasitology and an increasing drawing on resources world wide. In Christchurch, for example, a dead larva was identified in 1984 in a band of tissue which hyd been

obstructing the small bowel of a young woman. After surgical removal of the band the woman recovered well. Slides of the larva were sent to the School of Public Health and Tropical Medicine, New Orleans, where it was identified as an Anisakis larva — the first case reported in New Zealand.

Anisakiasis is not an uncommon disease in countries where raw fish is a delicacy. Anisakis larvae are killed when heated to greater than 60 degrees Centigrade but they survive certain preparation and preserving methods, such as brine curing, vinegar, and spice marination, smoking (unless a hot process is used), and home freezing. With the increased parasitic infections, the preventive role of health professionals in this work is becoming more important.