Three new cases of human infection with Dirofilaria repens, one pulmonary and two subcutaneous, in the Egyptian governorate of Assiut

Human dirofilariasis caused by Dirofilatia repens is a parasitic infection, currently considered to be an emerging zoonosis, that has been observed in many areas of the Old World. Dogs are the main 'reservoir' host. In humans, D. repens can cause inflammatory nodules, most commonly in the subcutaneous tissues or in the subconjunctival space. Lung involvement, which is the most common of the non-cutaneous and non-ocular manifestations, is frequently mis-diagnosed as a primary or metastatic lung tumour. Two new subcutaneous cases and one new pulmonary case, all observed in the Egyptian governorate of Assiut, are described here. This represents the first report of human pulmonary dirofilariasis caused by D. repens on the African continent. All the worms collected from the cases, including a living worm from the left lung of the pulmonary case, were identified morphologically, and the identity of the lung parasite was confirmed by PCR.