Strongyloides stercoralis infection in former Far East prisoners of war.

Out of 602 consecutive people who had been prisoners of war in the Far East and were screened for tropical diseases, 88 (15%) were found to have Strongyloides stercoralis infection a mean period of 30 years after their return from the tropics. The classical strongyloid creeping eruption was the most common symptom (84%), while gastrointestinal disturbances were rare (5%). Thiabendazole was highly effective in eradicating the infection. Strongyloidiasis is an important condition, as when the host is immunosuppressed fatal hyperinfection may occur. Many undiagnosed cases of strongyloidiasis must exist among former prisoners of war, and it is thus important to identify and treat these patients.     

Strongyloidiasis in Allied ex-prisoners of war in south-east Asia

One hundred and sixty ex-servicemen who had been prisoners of war in south-east Asia during 1942-5 were investigated for infection with Strongyloides stercoralis. Larvae were found in 44 (27·5%) of the men, who had therefore been infected for 34-37 years. Direct microscopy of the faeces was the most successful diagnostic method, giving a positive result in 37 cases (84%); multiple examinations were often necessary. Faecal culture was positive in 30 cases (68%), but examination of duodenal fluid obtained with the string test gave a positive result in only 17 (39%). The mean blood eosinophil count and mean serum IgE concentration were higher in the infected men, though normal values were often found in individual cases. Clinical manifestations of isolated strongyloides infection were analysed by comparing the infected men with control groups of ex-prisoners in south-east Asia without proved strongyloidiasis and ex-prisoners in Europe. Twenty-nine infected men (66%) complained of non-specific urticaria, and 13 (30%) had pathognomonic larva currens. Gastrointestinal symptoms significantly more common in the infected group were diarrhoea, indigestion, lower abdominal pain, pruritus ani, and weight loss (p <0·05-p <0·0005).The study group was thought to be reasonably representative of Allied ex-servicemen imprisoned in south-east Asia during the second world war. Probably there are many thousands of infected persons in several countries. The worm has an unusual ability to multiply, and larvae may spread throughout the body in immunosuppressed subjects.     

Insect taxonomic diversity in the Russian Far East

The insect fauna of the Russian Far East comprises 634 families from 31 orders. The estimated species number is 31500. The largest orders are Hymenoptera (76 families, 9000 estimated species), Diptera (120 families, 8000 estimated species), Coleoptera (114 families, 5500 estimated species), and Lepidoptera (81 families, 5000 estimated species). The fractions of the main insect orders in the fauna of the Russian Far East correspond to those in the Holarctic temperate zone. The high biodiversity of insects in the Russian Far East results from the position of this region extending across several climatic zones. There are four levels of diversity both for the families and for the species, corresponding to the tundra, taiga, the transitional area between taiga and broadleaved forests, and the broadleaved forest zone. The number of insect families increases by 3 times while that of species increases by 20 times from the tundra to the broadleaved forests. Differentiation of the insect fauna of the Russian Far East results from the recent climatic situation (the influence of the Pacific monsoon) and the geologic history (broadleaved forest refugia resulting from the absence of complete ice cover during Pleistocenic glaciation in the south of the Russian Far East); it reflects deep faunistic connections of the eastern Palaearctic with the Nearctic and Oriental Regions. The mountain areas in the North Pacific are the refugia of the Mesozoic and Tertiary insect faunas. The Pacific may have substantially reduced the Cenozoic aridization in the northern hemisphere, which was one of the important factors of formation of the recent biota in the Palaearctic and Nearctic regions.