P3.H142: Who let the dogs out?: A Case of Pneumonia Associated With Pulmonary and Hepatic Hydatid Disease from Ecuador

Introduction: Echinococcosis is a parasitic infection caused by larval tapeworms of the genus Echinococcus. It encompasses alveolar and cystic forms, predominantly affecting the lungs and liver. Transmission occurs mainly through zoonotic means, such as the contamination of water and food by infected dog feces. Delayed diagnosis may occur due to the nonspecific symptomatology which can mimic pneumonia. However, prompt diagnosis and treatment can lead to a cure. Here, we present a case involving delayed diagnosis of complex hepatic and pulmonary echinococcosis, initially misdiagnosed as pneumonia.

Case Description: A 6-year-old female from a rural area in Ecuador with a history of asthma and allergic rhinitis presented with a 3-day history of cough, vomiting, and fever. Febrile upon admission, with tachycardia and tachypnea. Physical examination revealed mild dehydration, decreased bilateral breath sounds, and bibasilar crackles. Laboratory findings showed leukocytosis, elevated CRP, and procalcitonin levels. Chest X-ray revealed consolidation in the left lung field. Consequently, she was admitted, diagnosed with pneumonia and initiated on ceftriaxone therapy. On hospital day 1, remained febrile with increasing oxygen requirements, prompting the need for a chest CT. Imaging revealed a cavitary lesion in the left inferior lobe, suggestive of complicated pneumonia with a lung abscess (Figure 1). Antibiotic therapy was adjusted to levofloxacin due to post-infusion urticaria, and vancomycin was initiated for MRSA coverage.

Subsequently, she was transferred to a tertiary care hospital. Reevaluation of her previous chest CT, along with an abdominal ultrasound that revealed a single hepatic cyst, raised suspicion of hydatid disease (Figure 2). Serology for Echinococcus granulosus returned positive. Upon further inquiry regarding contact with animals, and primary drinking water and food sources, the caregiver reported the presence of three unvetted household dogs.

A definitive diagnosis of acute bacterial pneumonia associated with hydatid disease was made. Patient completed 10-days of antibiotic therapy, and high-dose albendazole therapy was started prior to surgical resection of the lung cyst. Due to small size, the hepatic cyst was followed with conservative management. Histopathological exam confirmed echinococcosis. Fluid cultures were negative for bacteria, TB, and fungi. After 6 months, the patient completed antiparasitic therapy and fully recovered. Additionally, household members and pet deworming was recommended.

Discussion: Hydatid disease is commonly encountered in rural regions across Africa, Europe, Asia, the Middle East, Central and South America. Vigilance in suspecting echinococcosis is crucial, through meticulous history-taking, which uncovers potential transmission pathways, aiding in its prevention and control. In this case, the patient's living environment was key for diagnosis.

Conclusion: In resource-limited settings, clinicians should consider worm infections on their differential diagnosis when cystic-like masses appear on imaging and risk of transmission is present. Early evaluation and clinical suspicion of echinococcosis are essential for effective treatment. Increasing awareness is crucial for implementing public health control strategies.