An ulcerated nodule associated with lymphadenopathy

Viability and Desiccation Resistance of Bartonella henselae in Biological and Non-Biological Fluids: Evidence for Pathogen Environmental Stability

Pathogen environmental stability is an often-neglected research priority for pathogens that are known to be vector-transmitted. Bartonella henselae, the etiologic agent of Cat Scratch Disease, has become a "pathogen of interest" in several serious human illnesses, which include neoplastic, cardiovascular, neurocognitive, and rheumatologic conditions. Survival in the flea gut and feces as well as the association with a biofilm in culture-negative endocarditis provides insight into this organism's ability to adjust to environmental extremes. The detection of B. henselae DNA in blood and tissues from marine mammals also raises questions about environmental stability and modes of pathogen transmission. We investigated the ability of B. henselae to survive in fluid matrices chosen to mimic potential environmental sources of infective materials. Feline whole blood, serum and urine, bovine milk, and physiologic saline inoculated with a laboratory strain of B. henselae San Antonio 2 were subsequently evaluated by culture and qPCR at specified time intervals. Bacterial viability was also assessed following desiccation and reconstitution of each inoculated fluid matrix. Bartonella henselae SA2 was cultured from feline urine up to 24 h after inoculation, and from blood, serum, cow's milk, and physiologic saline for up to 7 days after inoculation. Of potential medical importance, bacteria were cultured following air-desiccation of all fluid inoculates. The viability and stability of Bartonella within biological and non-biological fluids in the environment may represent a previously unrecognized source of infection for animals and human beings.

Parotid mass due to cat scratch disease

Cat scratch disease (CSD), due to Bartonella henselae, is a self-limited chronic lymphadenopathy. A previously healthy 22-year-old woman presented with a palpable painful swelling in the right submandibular region accompanied by enlarged cervical lymph nodes. A diagnosis of B. henselae infection was made according to her personal history that divulged frequent contacts with cats and to a high titre of immunoglobulin G (IgG) and IgM antibodies for this agent. The patient improved within 1 month without the requirement of antibiotic treatment or surgery. The CSD should always be included in the differential diagnosis of all equivocal masses in the neck, especially in young individuals. In addition, it is important that a meticulous personal history is obtained.