CDC study on Cat Scratch Disease – Bartonella Henselae – finds a substantial burden of disease

New research from CDC on Cat scratch disease has just been published in the journal Emerging Infectious Disease. 

Cat-Scratch Disease in the United States, 2005–2013


Cat-scratch disease (CSD) is mostly preventable. More information about the epidemiology and extent of CSD would help direct prevention efforts to those at highest risk. To gain such information, we reviewed the 2005–2013 MarketScan national health insurance claims databases and identified patients <65 years of age with an inpatient admission or outpatient visit that included a CSD code from the International Classification of Diseases, Ninth Revision, Clinical Modification. Incidence of CSD was highest among those who lived in the southern United States (6.4 cases/100,000 population) and among children 5–9 years of age (9.4 cases/100,000 population). Inpatients were significantly more likely than outpatients to be male and 50–64 years of age. We estimate that each year, 12,000 outpatients are given a CSD diagnosis and 500 inpatients are hospitalized for CSD. Prevention measures (e.g., flea control for cats) are particularly helpful in southern states and in households with children.

and –

“CSD causes a substantial burden of disease nationwide and disproportionately affects children. Because CSD is a zoonotic infection that is maintained and spread among cats by fleas, comprehensive flea control for cats can help reduce the risk for human infection. Risk may also be reduced by washing hands after contact with cats, to remove potentially infectious flea feces that could enter breaks in the skin. Furthermore, because cats that hunt outdoors are at substantially greater risk for B. henselae bacteremia (17), limiting hunting activity of cats may reduce risk for human infection. Educational efforts should focus on cat owners, particularly those with children in the household or those with immunocompromising conditions. Additional research is warranted to elucidate the reasons for epidemiologic differences noted in this study and risk factors for severe disease.”



An interesting summary of this research is found on Galaxy Diagnostics website

  • CSD appears to be a bigger concern for immunocompetent adults and for females compared to men than previously recognized.
  • Average annual incidence of CSD is 4.7 per 100,000 persons <65 years of age in the US, with an estimated total of 12,500 patients receiving a CSD diagnosis each year in the United States.
  • Given the limitations of the MarketScan insurance claims database (a convenience sample excluding claims from persons >65 years of age, military personnel, uninsured persons, or Medicaid/Medicare enrollees), the actual incidence of CSD may be much higher. 

Evidence Beyond CSD

CSD and other types of Bartonellosis are not notifiable conditions. As a result, information on the epidemiology of Bartonella-related disease is extremely limited. Importantly, current research from teams around the globe have published important evidence further challenging traditional understandings of CSD and other Bartonella spp infections. Notable emerging evidence includes:

Fortunately, innovations in diagnostic approaches for confirmation of Bartonella spp infection in patient samples are driving research and discovery into the medical importance of these elusive bacteria and supporting efforts to raise awareness about the occupational risks and potential prevalence of Bartonella spp infection. 

Go to the link for further reading  –


Earlier posts on Bartonella :-


Understanding Bartonella

Risk Factors for Bartonella species Infection in Blood Donors from Southeast Brazil

RESEARCH GRANT – Enhanced Testing for the Diagnosis of Bartonellosis in Dogs

Bartonellosis: One health perspectives on an emerging infectious disease