THE PREVALENCE OF SERPULINA PILOSICOLI IN HUMANS AND DOMESTIC-ANIMALSIN THE EASTERN HIGHLANDS OF PAPNA NEW-GUINEA

In a survey of five villages in the Eastern Highlands of Papua New Gui nea, Serpulina pilosicoli was isolated from rectal swabs from 113 of 4 96 individuals (22.8%). Colonization rates ranged from 22.6-30.1% in f our of the villages but was only 8.6% in the other village. In compari son colonization was demonstrated in only 5 of 54 indigenous people (9 .3%) and none of 76 nonindigenous people living in an urban environmen t in the same region. Colonization did not relate to reported occurren ce of diarrhoea, age, sex, or length of time resident in a village. A second set of 94 faecal specimens was collected from I village 6 weeks after the first set. S. polysialic was isolated from 27 of 29 individ uals (93.1%) who were positive on the first sampling and from 7 of 65 individuals (10.8%) who previously were negative. In this case, isolat es were significantly more common in watery stools than in normal stoo ls. The annual incidence of infection in the village was calculated as 93.6%, with an average duration of infection of 117 days. S. pilosico li could not be isolated from any village pig (n = 126) despite its co nfirmed presence in 17 of 50 commercial pigs (34.0%) sampled at a loca l piggery. Four of 76 village dogs (5.3%) and 1 of 2 village ducks wer e colonized with S. pilosicoli, suggesting the possibility of cross tr ansmission between humans and animals.