Euan M. Scrimgeour

Ross River virus arthritis in Papua New Guinea

In 1975 it was reported that antibodies to Ross River virus (RRV) were present in the sera of many population groups in Papua New Guinea. We describe here 3 cases of polyarthritis that occurred in Port Moresby, the capital of Papua New Guinea, during 1980-81 and in which the diagnosis of RRV infection was confirmed by serological tests, and 3 other cases in which serological tests suggested RRV infection but were not diagnostic. A possible case of fatal RRV encephalitis is also reported.

A clinico-pathological study of a case of kuru

Kuru was diagnosed in a 42-year-old Melanesian male from the Eastern Highlands Province of Papua New Guinea. The clinical features indicated predominant cerebellar degeneration together with widespread cortical neuronal dysfunction and involvement of the diencephalon, hippocampus and basal ganglia. Dementia was an early and prominent feature. The duration of clinical illness was about 12 months and atypically he spent the last 7 months in hospital allowing continuous assessment. At autopsy, spongiform encephalopathy was demonstrated, and inoculation of brain tissue into 4 squirrel monkeys and 1 capuchin monkey resulted in the development of kuru. This is the longest continuous study of kuru in a hospital setting to be recorded in the adult human subject. The virus isolated from the brain of this patient has been adopted as a standard reference strain of kuru for future use and repository.

Levels of serum cholesterol, triglyceride, HDL-cholesterol, apoproteins A-l and B, and plasma glucose, and prevalence of diastolic hypertension and cigarette smoking in papua new guinea highlanders

&NA; Coronary heart disease (CHD) is rare in Papua New Guinea (PNG) highlanders. Fifty‐two men and 69 women randomly selected from three rural communities and a low socioeconomic urban community in the Eastern Highlands Province were assessed for hyperlipidemia, diabetes mellitus, diastolic hypertension and cigarette smoking. There was no significant difference between the findings in the rural and urban groups. The mean fasting levels of serum cholesterol, HDL cholesterol and apoproteins A‐l and B were significantly lower (p< 0.001) than those of rural Australians in a comparative study but the serum triglyceride levels were significantly higher in men <30 yr and women < 40 yr of age. There was no significant difference in the serum cholesterol levels in men and women, and the levels of serum cholesterol and triglyceride did not rise with age. The mean fasting levels of plasma glucose were generally lower in PNG subjects and only two (1.7%) had diabetes mellitus. The proportions of highlanders who had diastolic hypertension or who smoked cigarettes were similar to those of Australian populations generally. The low incidence of CHD in PNG highlanders is probably related to the low serum cholesterol and apoprotein B levels, in turn probably related to their basically vegetarian diet and physically active life‐style.

Distribution of Angiostrongylus cantonesis in Papua New Guinea

Abstract Examination of 97 rats trapped in Port Moresby and Lae on the mainland of Papua New Guinea and in Rabaul, East New Britain Province, showed that 124% were infected by Angiostrongylus cantonensis . Larval An. cantonensis were found in Achatina fulica snails collected at these towns, from the Ramu Valley near Madang on the mainland and at locations in West New Britain, New Ireland and Bougainville Island. The mollusc infection rates ranged from 12·7% at Port Moresby to 32·4% at Kimbe in West New Britain (mean: 19·2%). Larvae obtained from snails from Port Moresby, Lae, the Ramu Valley and Rabaul were fed to laboratory rats and mature nematodes obtained subsequently provided confirmation that the species was An. cantonensis. Ach. fulica has not yet colonized the Highland region of Papua New Guinea and rats trapped in Goroka were free of infection. Human angiostrongyliasis has now been reported from Rabaul and studies have shown a high level of immunological responsiveness to the parasite in the sera of residents of East New Britain.

Chronic pulmonary cryptococcosis in a Rattus rattus from Rabaul, Papua New Guinea

A wild Rattus rattus trapped in Rabaul, East New Britain Province, Papua New Guinea, was noted to have chronic, cystic pulmonary cryptococcosis. R. rattus is common in settlements in Papua New Guinea whereas pigeons, which have been suspected as a possible source of human cryptococcosis, rarely nest in villages in this country. If R. rattus was susceptible to chronic pulmonary cryptococcosis, because of its habit of nesting in roofs, it could serve as a possible vector of human cryptococcosis in Papua New Guinea and perhaps in other countries as well.

Angiostrongylus cantonensis in East New Britain, Papua New Guinea

The first case of angiostrongyliasis (eosinophilic meningitis) to be diagnosed in Papua New Guinea in 1977, led to a survey of adult Melanesian residents of East New Britain province where the case occurred, to assess the level of immunological responsiveness to Angiostrongylus cantonensis. In 104 subjects tested using an indirect fluorescent antibody test, the serum antibody titres to A. cantonensis equalled or exceeded 1:16 in 50.7% and ranged from 1:32 to 1:64 in 17.3% of subjects. No individual tested showed evidence of active or recent angiostrongyliasis but in a patient suspected to have ocular angiostrongyliasis, the antibody titre of A. cantonensis was 1:128 in the single serum specimen obtained. In a programme to determine the distribution of this parasite in the natural hosts, 19 rats were trapped; one had adult A. cantonensis in its pulmonary arteries. Examination of 200 Achatina fulica snails revealed Angiostrongylus larvae in 62 (31%) and when these larvae were fed to laboratory rats, adult A. cantonensis were subsequently recovered from their pulmonary arteries.