Case series of four patients with strongyloides after occupational exposure

TO THE EDITOR: Strongyloidosis in Australia has been reported in Indigenous Australians, war veterans who have served in South-East Asia and travellers and immigrants from regions in which strongyloidosis is endemic.1,2 The condition is caused by Strongyloides stercoralis, and chronic infection with the nematode is maintained by an autoinfective life cycle. The consequences of infection range from asymptomatic minor infection to chronic symptomatic strongyloidosis. In immunocompromised people, lifethreatening dissemination can occur3 with a mortality of nearly 90%.2 In the past 8 years at Alice Springs Hospital, four people have presented with strongyloidosis, in whom the only identifiable exposure was their occupation. Work-related exposure resulting in S. stercoralis infection has been documented previously in healthy Australian medical professionals volunteering in the Solomon Islands.4 In our series, Patient 1 was a middle-aged white man who had previously worked as a teacher in an Indigenous school. He had documented Still’s disease treated with prednisolone, methotrexate and hydroxychloroquine, and presented with urticaria, diarrhoea and a cough. Patient 2 was a child care worker with rheumatoid arthritis, treated with methotrexate and hydroxychloroquine. She presented with a rash, cough, wheezing and eosinophilia. Patient 3 was a middle-aged ex-nurse treated with methotrexate for rheumatoid arthritis, who presented with recurrent epigastric pain. Patient 4 was a paediatrician with systemic lupus erythematosis, who developed abdominal pain, nausea, diarrhoea and eosinophilia after commencing prednisolone for worsening arthralgia and vasculitis. All four patients tested positive for S. stercoralis in serological tests. The “gold standard” for diagnosis of strongyloides infection is finding typical larvae in stool samples or biopsies, but the strongyloides serological test has a sensitivity of 97% and a specificity of 100%.5 Symptoms for all four patients resolved with two doses of ivermectin 200 mg/kg, spaced 2 weeks apart. Follow-up serological tests performed 6 months later showed an adequate reduction in titres. This case series describes four individuals who were exposed to strongyloides at work, and highlights the importance of considering strongyloidosis in patients with possible occupational exposure, especially in those on immunosuppressive therapy.3 Whether professionals with occupational exposure to strongyloides should be routinely screened for infection, or should receive regular empirical ivermectin treatment, is of potential debate.