Pulmonary Strongyloidiasis and Hyperinfection Syndrome

Abstract

INTRODUCTION: We report a case of refractory asthma in an immunocompromised patient found to have pulmonary strongyloidiasis, who developed septic shock and multiorgan failure due to bacterial translocation consistent with Hyperinfection syndrome. CASE PRESENTATION: A 65 year old man with chronic lymphoid leukemia and recent progression to myelodysplastic syndrome on steroid therapy presented with worsening shortness of breath. He had a history of farming angus cows. The patient had two recent admissions to the hospital for cough, wheezing and respiratory distress, where he was treated with steroids and antibiotics although no pathogenic organism was isolated. His pulmonary function tests from a few months ago showed severe airflow obstruction with significant bronchodilator response. On physical exam he had coarse breath sounds with bilateral rhonchi and wheezing. Abnormal laboratory findings included a white blood cell count of 16000 with 30% eosinophils [fig 1A and 1B show white blood cell count and differential trend in last five months]. The chest x-ray showed reticulonodular pattern [fig 2], while the CT chest showed new micronodules mostly in the right lower lobe [fig 3]. He was admitted to the intensive care unit with refractory septic shock and started on broad spectrum antibiotics. His IgE was 28.2 and the vasculitis work up was negative. Bronchoscopic examination showed diffuse erythema with mucopurulent secretions. [fig 4]. His bronchoalveolar lavage showed Strongyloides Stercoralis consistent with pulmonary strongyloidiasis [fig 5 and 6], and the blood cultures grew multi drug resistant Escherichia coli suggesting Hyperinfection syndrome. DISCUSSION: Pulmonary Strongyloidiasis is caused by Strongyloides Stercoralis. The larvae penetrate skin and migrate hematogenously to the lungs. The rhabditiform larvae in gastrointestinal tract mature into infectious filariform larvae, which can penetrate colonic mucosa causing Hyperinfection Syndrome in the immunocompromised host1 especially if they are in contact with cows. Hyperinfection syndrome with secondary bacterial translocation can cause septic shock, multiorgan failure and mortality as high as 80% has been reported. Pulmonary Strongyloidiasis can cause persistent eosinophilia2, cough, dyspnea, wheezing, asthma, hemoptysis, pneumonitis and acute respiratory failure. Pulmonary consolidation3 and micronodules on CT chest may be present. ELISA, stool examination and bronchoalveolar lavage are initial diagnostic tests. Combination of ivermectin with albendazole is suggested treatment of hyperinfection syndrome. CONCLUSIONS: The refractory asthma, persistent peripheral eosinophilia and new micronodular pattern on chest imaging in an immunocompromised host should raise suspicion of pulmonary strongyloidiasis, as the early initiation of therapy can prevent fatal Hyperinfection Syndrome.