16 JANUARY 1998. INDONESIA: DISEASE (JAPANESE ENCEPHALITIS)
"Presumptive JE infection was demonstrated serologically by Dr. Roy Hall and Cheryl Johansen at the University of Queensland, and this diagnosis was confirmed by Dr. Annette Broom at the University of Western Australia and Mrs. Debbie Phillips at Queensland Health Scientific Services.

Serological studies using a competitive ELISA have been carried out on sera collected from a number of different sites in south-western Papua New Guinea by Cheryl Johansen and Dr. Hall at the University of Queensland in Brisbane and by Wayne Melrose at James Cook University in Townsville. They found that JE virus has been active in the Daru area of Western Province since at least 1989 with 21% of sera found to be antibody positive. An increasing antibody positivity has also been observed in the Upper Fly region, rising from 8% in 1990-1991 to 24% in 1993, and JE antibody positive sera have been observed in Kareema region of Gulf Province and Lake Kutubu in Southern Highlands Province. However no JE virus activity has been observed in northern or eastern PNG, although antibodies to Murray Valley encephalitis and Kunjin viruses have been found in sera collected in these areas.

Most pig sera collected from Western Province by Dr. Jack Shield in 1995-96 were also seropositive for JE virus. The present increased JE virus activity and the two human cases in the Upper Fly region has occurred during a period of extreme drought. I understand that there has been increased mosquito breeding in the area as streams and rivers dry to form pools of stagnant water, and the flushing action of running streams ceases. I would assume that these reduced areas of water may also concentrate water birds and feral animals, allowing a greater potential for arboviral transmission."--John Mackenzie <jmac@biosci.uq.edu.au> in the Indonesian Nature Conservation List <edcolijn@noord.bart.nl