Low prevalence of strongyloidiasis in Far North Queensland pregnant women

Abstract

INTRODUCTIONStrongyloidiasis is a neglected tropical disease caused by the parasite Strongyloides stercoralis that remains consistently under-researched despite an estimated worldwide prevalence of 370 million people. 1 Strongyloidiasis is of particular concern to immunosuppressed patients, in which the parasite can proliferate rapidly (hyperinfection syndrome), with a mortality of 70%-100%. 1 Pregnant women are potentially at risk of hyperinfection syndrome, due to the combined effects of immunosuppression during pregnancy and the prescription of corticosteroids, which are routinely administered if a preterm birth is suspected. 2 In a 2015 reported case from New York, a Haitian woman died and her foetus was stillborn. 2 Moreover, the offspring of chronically infected mothers are at risk of low birthweight.Cairns is the largest city in tropical Far North Queensland (FNQ), in a region in which strongyloidiasis is suspected to be hyper-endemic. Little is known about the current burden of strongyloidiasis, as studies typically show inconsistent prevalence data from single towns, which due to their unique socioeconomic circumstances cannot be generalized to the whole region. Two studies in rural Queensland found prevalences of 4% and 12%, respectively, 3,4 while a study in the Kimberley found 36%. 5 Without reliable, up-to-date prevalence studies clinicians are unable to appropriately screen and treat at-risk patients.We performed a prospective cohort study examining the prevalence and clinical burden of strongyloidiasis in pregnant women in FNQ. From January to July 2018, all women able to provide informed consent were invited to participate at antenatal clinics at Cairns Hospital, irrespective of age, ethnicity or medical co-morbidities. Consented women had S. stercoralis serology added to their routine prenatal blood tests and were then followed until the end of their pregnancy. Cairns Hospital is the main health service performing deliveries for FNQ including the Torres Strait, making this site a suitable location to collect an accurate sample and accurately describe Strongyloides' prevalence. The study received ethical approval from the FNQ Human Research Ethics Committee (Reference Number HREC/17/QCH/25-1125).Eighty-seven women were approached for involvement with one woman declining, leaving 86 women who consented for involvement in this study (Table 1). Compliance with the testing protocol was challenging: amongst the 86 consented participants, only 60 then went on to complete testing for S. stercoralis. In contrast to our hypothesis, a very low prevalence rate of 3.3% (two patients, 95% CI, 0.8%-12.5%) was recorded amongst the cohort. Both were Aboriginal or Torres Strait Island Australians and one had type two diabetes mellitus, one from the greater Cairns region and one from a remote community. No child complications were observed, and the seropositive participants were treated. | 439 PALTRIDGE ET AL.Neither of the two participants who were positive for S. stercoralis had eosinophilia. This corroborates th...

A Review on Strongyloidiasis in Pregnant Women

“…Difficulties in compliance with testing protocols using serology have been reported. 20 There is a clear need to include reliable serological tests in further studies of Strongyloides prevalence in pregnant women. Worldwide, health-care providers would benefit from more accurate prevalence data to appropriately manage strongyloidiasis in pregnant women and women of childbearing age.…”

“… 15 , 19 In an Australian study, there were implementation issues leading to only 60 of 86 women being screened by serology, and seroprevalence of 3.3% was reported. 20 …”