Author(s): Christina Nelson

BARTONELLA QUINTANA INFECTION

CARRIÓN DISEASE

CAT SCRATCH DISEASE

Infectious Agent

Several gram-negative bacteria in the genus Bartonella cause human disease through various transmission routes. Human illness primarily is caused by B. quintana (known historically as “trench fever”), B. bacilliformis (Carrión disease), and B. henselae (cat scratch disease [CSD]). A variety of Bartonella spp. can cause subacute, culture-negative endocarditis; other clinical syndromes (e.g., encephalitis, ocular disease, osteomyelitis) due to Bartonella spp. have been reported. Additional Bartonella spp. that cause human illness have been described recently.

Transmission

B. quintana is transmitted by the human body louse; B. bacilliformis is transmitted by infected phlebotomine sand flies of the genus Lutzomyia; and B. henselae is transmitted through scratches from domestic or feral cats, particularly kittens. Direct transmission of B. henselae to humans by the bite of infected cat fleas likely can occur but has not yet been proven.

Epidemiology

B. quintana and CSD infections occur worldwide. B. quintana infections typically occur in populations that lack access to proper hygiene, (e.g., refugees living in crowded conditions, people experiencing homelessness). Minimal data are reported on CSD among travelers, but in the United States, CSD is more common in children, in southern states, and during the months August–January.

Carrión disease has limited geographic distribution; transmission occurs in the Andes Mountains at 1,000–3,000 m (≈3,300–9,800 ft) elevation. Most cases are reported in Peru, but cases have also occurred in Bolivia, Chile, Colombia, and Ecuador. Short-term travelers to endemic areas are likely at low risk.

Clinical Presentation

Bartonella quintana Infection

Symptoms of B. quintana infection include fever, headache, transient rash, and bone pain, mainly in the shins, neck, and back.

Carrión Disease

Carrión disease has 2 distinct phases: an acute phase (Oroya fever) characterized by fever, myalgia, headache, and anemia; and an eruptive phase (verruga peruana) characterized by red-to-purple nodular skin lesions.

Cat Scratch Disease

CSD typically manifests as a papule or pustule at the inoculation site and enlarged, tender lymph nodes that develop proximal to the inoculation site 1–3 weeks after exposure. B. henselae infections also can cause prolonged fever. Atypical manifestations include follicular conjunctivitis, encephalitis, neuroretinitis, osteomyelitis, or infection of the liver or spleen.

Bacillary Angiomatosis

Bacillary angiomatosis can present as skin, subcutaneous, or bone lesions, and is caused by B. henselae or B. quintana; peliosis hepatis manifests as liver lesions and is caused by B. henselae. Both occur primarily in people infected with HIV.

Diagnosis

Bartonella quintana Infection

B. quintana infection can be diagnosed by serology, polymerase chain reaction (PCR) testing, or blood culture. Endocarditis caused by Bartonella spp. can be diagnosed by elevated serology and by PCR or culture of excised heart valve tissue.

Carrión Disease

Oroya fever is typically diagnosed via blood culture or direct observation of the bacilli in peripheral blood smears, but sensitivity of these methods is low. PCR and serologic testing also might aid diagnosis. Clinicians can contact CDC’s Division of Vector-Borne Diseases for diagnostic consultation by calling 970-221-6400.

Cat Scratch Disease

CSD can be diagnosed presumptively in patients with typical presentation and a compatible exposure history. Serology can confirm the diagnosis, although cross-reactivity might limit interpretation in some circumstances. Serology is available from large commercial laboratories. B. henselae also can be detected by PCR or culture of lymph node aspirates by using special techniques. Some specialized laboratories offer Bartonella testing with novel techniques, but lack adequate clinical validation data; clinicians should consider these options with caution.

Treatment

Each variation of Bartonella infection has distinct recommended treatments.

Bartonella quintana Infection

Doxycycline plus gentamicin is the recommended treatment for B. quintana bacteremia and associated symptoms (e.g., fever and rash).

Carrión Disease

Treat Oroya fever using chloramphenicol or ciprofloxacin.

Cat Scratch Disease

Antibiotics may not be necessary for the treatment of typical CSD, since it can resolve without treatment. Consider prescribing azithromycin for patients with extensive lymphadenopathy or to shorten the course of disease.

A small percentage of people will develop disseminated disease with severe complications. The effect of antibiotic treatment in reducing risk of progression to atypical disease is unknown. Doxycycline plus rifampin appears to promote disease resolution for B. henselae neuroretinitis; regimens and duration of treatment might vary by clinical presentation.

Prevention

Travelers should protect themselves from bites of body lice and sand flies (see Sec. 4, Ch. 6, Mosquitoes, Ticks & Other Arthropods). People, especially those who are immunocompromised, should avoid kittens and stray cats; rough play with associated scratches is a particular risk. People can reduce the risk for cats to carry B. henselae by controlling fleas and limiting cats’ outdoor roaming. People also should wash their hands promptly after handling cats.

CDC website: Bartonella