Strongyloides and COVID-19: Challenges and Opportunities for Future Research

Strongyloides Hyperinfection Syndrome Following Immunosuppressant Therapy for COVID-19: A Case Report With Literature Review

Strongyloides hyperinfection and disseminated infections are usually associated with immunosuppression; these severe manifestations occur in a minority of cases. The use of immunosuppressants such as corticosteroids and Baricitinib for treating COVID-19 pneumonia can be responsible for patients' immunosuppression and cause Strongyloides hyperinfection syndrome. The chance increases when the patient belongs to countries or regions where chronic infection with Strongyloides is more prevalent. This case report describes the clinical scenario of a 78-year-old man from southeastern Bangladesh who was initially diagnosed with COVID-19 pneumonia. His condition improved after receiving corticosteroid therapy for approximately 1 month at various doses and Baricitinib therapy for more than a week due to moderate-to-severe COVID-19 pneumonia. Approximately 2 months later, he presented with low-grade fever, diarrhea, and itching throughout the body. Blood analysis revealed eosinophilia; stool examination revealed Rhabditiform larvae of Strongyloides stercoralis. The patient was diagnosed with Strongyloides hyperinfection syndrome and treated with Albendazole and Ivermectin. His clinical condition gradually improved, and he was discharged from the hospital. The stool sample was sent for a repeat microscopic examination after 14 days, which yielded a negative result. Clinicians should be more vigilant while prescribing corticosteroids and other immunosuppressants for a prolonged period. Proper screening to identify asymptomatic cases of strongyloidiasis, followed by empirical treatment of screening-positive cases, prompt detection, and management of severe manifestations, is crucial to reduce further morbidity and mortality related to Strongyloides stercoralis.

Strongyloides stercoralis hyperinfection presenting pneumatosis intestinalis and acute respiratory distress syndrome after treatment for COVID-19

A 91-year-old man was admitted with vomiting and abdominal pain. He had had COVID-19 pneumonia a month before and the treatment had consisted of remdesivir, dexamethasone and baricitinib. CT scans showed pneumatosis intestinalis. His respiratory condition rapidly deteriorated and chest CT scans showed ground-glass opacity and Strongyloides stercoralis was identified in the sputum, making a diagnosis of hyperinfection syndrome associated acute respiratory distress syndrome. Treatment of ivermectin was not achieved in time and he died of multiple organ failure. S. stercoralis is a soil-transmitted helminth endemic to tropical and subtropical areas. Immunosuppressive conditions can cause hyperinfection syndrome and life-threatening conditions. Our case highlights the importance of assessing for untreated chronic strongyloidiasis in COVID-19 patients requiring steroid treatment in endemic areas.

Strongyloidiasis

Strongyloidiasis is a neglected tropical disease caused primarily by the roundworm Strongyloides stercoralis. Strongyloidiasis is most prevalent in Southeast Asia and the Western Pacific. Although cases have been documented worldwide, global prevalence is largely unknown due to limited surveillance. Infection of the definitive human host occurs via direct skin penetration of the infective filariform larvae. Parasitic females reside in the small intestine and reproduce via parthenogenesis, where eggs hatch inside the host before rhabditiform larvae are excreted in faeces to begin the single generation free-living life cycle. Rhabditiform larvae can also develop directly into infectious filariform larvae in the gut and cause autoinfection. Although many are asymptomatic, infected individuals may report a range of non-specific gastrointestinal, respiratory or skin symptoms. Autoinfection may cause hyperinfection and disseminated strongyloidiasis in immunocompromised individuals, which is often fatal. Diagnosis requires direct examination of larvae in clinical specimens, positive serology or nucleic acid detection. However, there is a lack of standardization of techniques for all diagnostic types. Ivermectin is the treatment of choice. Control and elimination of strongyloidiasis will require a multifaceted, integrated approach, including highly sensitive and standardized diagnostics, active surveillance, health information, education and communication strategies, improved water, sanitation and hygiene, access to efficacious treatment, vaccine development and better integration and acknowledgement in current helminth control programmes.