Wolbachia pipientis Infection

Wolbachia pipientis is a gram-negative bacteria belonging to the family Anaplasmataceae. The organism is found in all developmental stages of Dirofilaria immitis, the filarial helminth that causes heartworm disease in dogs and cats. While Wolbachia may collaborate in the pathogenesis of Dirofilaria immitis infection, clinical signs are indistinguishable from heartworm disease. Treating dogs infected with Dirofilaria immitis with an antibiotic that targets Wolbachia results in a decrease in microfilaremia, and when combined with ivermectin, fewer pathologic pulmonary lesions are observed compared to adulticide therapy alone. Because all Dirofilaria immitis are infected with Wolbachia, the prognosis of Wolbachia infection follows the prognosis for treatment of heartworm infections. Dirofilaria immitis is able to infect humans, where it generally causes granulomatous lesions in lungs and subcutaneous tissue.