Pulmonary Loiasis and HIV Coinfection in Rural Cameroon

A 38-year-old man presented to a rural hospital in Northwest Cameroon with a one-month history of dyspnea that worsened upon exertion. He reported occasional cough, which was nonproductive. Review of systems revealed a fall in weight from 81 kg to 71 kg over the last year, but no other problems were noted. The patient initially sought care at a health center in Douala (10 hours away by public transport), where he was treated for typhoid with no improvement. On physical examination, temperature was 37.8uC, blood pressure 110/ 70 mmHg, pulse 88 beats per minute, and respiratory rate 28 breaths per minute. He was noncachectic without thrush or lymphadenopathy. Lung auscultation revealed no bronchial breath sounds or wheezes, but decreased breath sounds and dullness to percussion were noted at both lung bases, and a chest radiograph showed dense bibasilar opacities (Figure 1). Diagnostic thoracentesis confirmed the presence of exudative pleural effusion; cytological examination yielded 435 white blood cells/ mm (84% lymphocytes, 10% neutrophils, and 6% eosinophils), 240 red blood cells/ mm, and numerous motile microfilariae (mff) throughout the specimen (see Video S1). A smear was made of the pleural aspirate and the filarial species identified as Loa loa based on morphological features (Figure 2). Other laboratory investigations included hemoglobin of 9.3 mg/dl, white blood cells 9,800/mm, a thick blood film negative for malaria parasites, and a positive HIV serology test. His CD4 count was 954 cells/ml. Peripheral blood was not examined for microfilariae. After discussing these results with his physician, the patient received a single dose of ivermectin (150 mg/kg body weight) and all other medications that had been ordered by the admitting team— including multiple broad-spectrum antibiotics, ventolin, and amodiaquine—were stopped. A short course of prednisone was initiated to reduce potential reaction to parasite antigens. The next day, he left the hospital in stable condition. Follow-up examination three weeks later showed normalization of his vital signs and total resolution of the pleural effusions on repeat radiography (Figure 1). The patient was encouraged to participate in the annual ivermectin campaigns common in the area and to monitor his HIV infection at his local medical center.