HTLV-I and Strongyloides in Australia: The worm lurking beneath.

Strongyloidiasis and HTLV-I (human T-lymphotropic virus-1) are important infections that are endemic in many countries around the world with an estimated 370 million infected with Strongyloides stercoralis alone, and 5-10 million with HTVL-I. Co-infections with these pathogens are associated with significant morbidity and can be fatal. HTLV-I infects T-cells thus causing dysregulation of the immune system which has been linked to dissemination and hyperinfection of S. stercoralis leading to bacterial sepsis which can result in death. Both of these pathogens are endemic in Australia primarily in remote communities in Queensland, the Northern Territory, and Western Australia. Other cases in Australia have occurred in immigrants and refugees, returned travellers, and Australian Defence Force personnel. HTLV-I infection is lifelong with no known cure. Strongyloidiasis is a long-term chronic disease that can remain latent for decades, as shown by infections diagnosed in prisoners of war from World War II and the Vietnam War testing positive decades after they returned from these conflicts. This review aims to shed light on concomitant infections of HTLV-I with S. stercoralis primarily in Australia but in the global context as well.

Cross-Cultural, Aboriginal Language, Discovery Education for Health Literacy and Informed Consent in a Remote Aboriginal Community in the Northern Territory, Australia.

BACKGROUND: Education for health literacy of Australian Aboriginal people living remotely is challenging as their languages and worldviews are quite different from English language and Western worldviews. Becoming health literate depends on receiving comprehensible information in a culturally acceptable manner. METHODS: The study objective was to facilitate oral health literacy through community education about scabies and strongyloidiasis, including their transmission and control, preceding an ivermectin mass drug administration (MDA) for these diseases. A discovery education approach where health concepts are connected to cultural knowledge in the local language was used. Aboriginal and non-Aboriginal educators worked collaboratively to produce an in-depth flip-chart of the relevant stories in the local language and to share them with clan elders and 27% of the population. RESULTS: The community health education was well received. Feedback indicated that the stories were being discussed in the community and that the mode of transmission of strongyloidiasis was understood. Two-thirds of the population participated in the MDA. This study documents the principles and practice of a method of making important Western health knowledge comprehensible to Aboriginal people. This method would be applicable wherever language and culture of the people differ from language and culture of health professionals.

A comparative study of intestinal helminths in pre-school-age urban and rural children in Morobe Province, Papua New Guinea.

Children aged between 1 month and 10 years from one rural coastal locality, two rural upland localities and two urban localities in Morobe Province, Papua New Guinea were examined between September 1980 and September 1982. Hookworm (predominantly Necator americanus), Ascaris lumbricoides and Trichuris trichiura increased in prevalence with age. The prevalence of Strongyloides fuelleborni subspecies kellyi, where present, was either highest in the < 1 year age group or similar in all age groups. N. americanus prevalence was between 59% and 83% in the 3 year age group except at the coastal locality, where it was 15%. A. lumbricoides prevalence in the 3 year age group was very low in one upland locality and between 7% and 41% for the other localities. T. trichiura prevalence in the 3 year age group was between 33% and 55% at the coastal and two urban localities, and very low at the two upland localities. S. f. kellyi prevalence in the < 1 year age group was 48% and 20% respectively at the two upland localities, 2% at one of the urban localities and not detected at the other localities. Strongyloides stercoralis was detected at both urban localities, but not at the coastal locality or at the upland locality where testing was done. Many children had infections of more than one species, and there was a significant association of A. lumbricoides with T. trichiura at the coastal and two urban localities. The presence of S. f. kellyi at one of the urban localities raises the possibility that this once isolated species may now be spreading as infected people visit and settle in the towns. Between 68% and 93% of children in the 3 year age group and between 65% and 100% in the 5 year age group were infected with at least one helminth species.

A comparative study of intestinal helminths in pre-school-age urban and rural children in Morobe Province, Papua New Guinea

Children aged between 1 month and 10 years from one rural coastal locality, two rural upland localities and two urban localities in Morobe Province, Papua New Guinea were examined between September 1980 and September 1982. Hookworm (predominantly Necator americanus), Ascaris lumbricoides and Trichuris trichiura increased in prevalence with age. The prevalence of Strongyloides fuelleborni subspecies kellyi, where present, was either highest in the < 1 year age group or similar in all age groups. N. americanus prevalence was between 59% and 83% in the 3 year age group except at the coastal locality, where it was 15%. A. lumbricoides prevalence in the 3 year age group was very low in one upland locality and between 7% and 41% for the other localities. T. trichiura prevalence in the 3 year age group was between 33% and 55% at the coastal and two urban localities, and very low at the two upland localities. S. f. kellyi prevalence in the < 1 year age group was 48% and 20% respectively at the two upland localities, 2% at one of the urban localities and not detected at the other localities. Strongyloides stercoralis was detected at both urban localities, but not at the coastal locality or at the upland locality where testing was done. Many children had infections of more than one species, and there was a significant association of A. lumbricoides with T. trichiura at the coastal and two urban localities. The presence of S. f. kellyi at one of the urban localities raises the possibility that this once isolated species may now be spreading as infected people visit and settle in the towns. Between 68% and 93% of children in the 3 year age group and between 65% and 100% in the 5 year age group were infected with at least one helminth species.

Effective diagnostic tests and anthelmintic treatment for Strongyloides stercoralis make community control feasible.

Strongyloides stercoralis is endemic in tropical and subtropical countries, and is prevalent particularly in economically impoverished people. Although an estimated 30 to 100 million people world-wide suffer from S. stercoralis infection and it is a life-long disease, it remains a neglected tropical disease. Faecal testing for S. stercoralis is very insensitive. The prevalence of S. stercoralis in Indigenous Australians (up to 60%) is much higher than previously thought, and its prevalence in Papua New Guinea is likely to be much higher than currently believed. When S. stercoralis and the HTLV-1 virus coexist in the one person, both diseases progress more quickly than when either infection is on its own. When people become infected with S. stercoralis, they develop acute strongyloidiasis which may be life threatening. At any time during the course of the disease, if the immune system is suppressed, most often by corticosteroid drugs, infected people may develop hyperinfective strongyloidiasis and they will die unless the underlying S. stercoralis infection is effectively treated. The use of serology for diagnosis, together with ivermectin treatment, has revealed that it is possible to eradicate S. stercoralis from the patient, and serology can also define the effectiveness of treatment. The reservoir of infection is humans; the free-living stages are short-lived. Mass treatment may be effective at eliminating S. stercoralis from a community. Safe water and effective sanitation alone do not lead to elimination of S. stercoralis. Up-to-date knowledge of S. stercoralis has been revealed through the workshops of the National Strongyloides Working Group in Australia and is summarized here. Much of this information is now available on the world wide web, and the addresses of relevant web sites are given.