1971. Onchocerca lupi: An Emerging Parasitic Infection in the Southwestern United States
Session: Oral Abstract Session: Emerging Public Health Threats
Saturday, October 10, 2015: 3:15 PM
Room: 25--ABC
Background: Onchocerca lupi is a zoonotic parasite that causes canine and feline eye disease. Eye disease due to O. lupi has been described in 7 patients from Europe, Asia, and the Middle East since it was identified in humans in 2011.  Little is known about O. lupi, its definitive host, insect vector, and the spectrum of disease in humans.

Methods: This report describes the first 6 cases of O. lupi human infection in the US, including geographic and clinical characteristics, and management.  

Results: All patients resided in the southwestern US (Table); some traveled to CO and UT.  Five cases occurred in children. Cases 2 and 3 reported insect bites at the nodule site years prior to presentation. Case 6 owned a dog with eye lesions. All presenting symptoms were attributed to a nodule containing an adult nematode. Three nodules were found in the cervical spinal canal, two in subcutaneous tissues of the scalp and forearm, and one in the superior rectus muscle of the orbit. The cervical spine nodules in cases 1 and 5 contained a gravid female nematode. Treatment included surgical excision and antiparasitic treatment for most cases.  Five patients with follow up information available remained asymptomatic following treatment.

 

Case 1

Case 2

Case 3

Case 4

Case 5

Case 6

Age

22 mo

10 y

50 y

13 y

5 y

10 y

Residence

AZ

NM

AZ

AZ

NM

TX

Presentation

Cervical spine mass

Scalp nodule

Forearm nodule

Cervical spine mass

Cervical spine mass

Superior rectus muscle nodule

Diagnosis

Histologic

Histologic

PCR

Histologic

PCR

Histologic

Histologic

Histologic

PCR

Nematode

Gravid female

Non-gravid adult

Non-gravid adult

Non-gravid adult

Gravid female

Non-gravid adult

Evaluation

Skin snips

Eye exam

Eye exam

Lumbar puncture, eye exam

Lumbar puncture, eye exam

None

Management

Biopsy

Ivermectin

Excision

Excision

Ivermectin Doxycycline

Partial excision

Corticosteroids Ivermectin Doxycycline

Excision

Ivermectin Doxycycline

Excision

Ivermectin Doxycycline

Conclusion: There appears to be a transmission cycle for O. lupi in the southwestern US that involves humans, dogs, and cats. In the US, the clinical presentation has been more invasive than elsewhere.  Continued investigation is needed to describe the spectrum of human disease, develop approaches for diagnosis and treatment, and create prevention strategies.

Christiana Smith, MD1, Suchitra Rao, MB, BS1, Walter Dehority, MD, MSc2, G. Amin Ostovar, MD3, Maria Alzona, MD4, Jill E. Weatherhead, MD5, Morven Edwards, MD, FIDSA, FPIDS6, Jessica Weeks, MD7, Andrew Terranella, MD7, Marcos E. De Almeida, PhD8, Blaine Mathison, BS8, Henry Bishop, BS8, Mark Eberhard, PhD8 and Paul Cantey, MD, MPH8, (1)Pediatric Infectious Diseases, University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO, (2)Pediatrics, University of New Mexico, Albuquerque, NM, (3)Pediatrics, Maricopa Medical Center, Phoenix, AZ, (4)Clin-Path Associates, Tempe, AZ, (5)Pediatrics-Tropical Medicine, Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, (6)Baylor College of Medicine, Houston, TX, (7)Indian Health Service, Window Rock, AZ, (8)Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, GA

Disclosures:

C. Smith, None

S. Rao, None

W. Dehority, None

G. A. Ostovar, None

M. Alzona, None

J. E. Weatherhead, None

M. Edwards, None

J. Weeks, None

A. Terranella, None

M. E. De Almeida, None

B. Mathison, None

H. Bishop, None

M. Eberhard, None

P. Cantey, None

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