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

Abstract

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.

Keywords: Bartonella henselae; Cat scratch disease; United States; bacteria; fleas; lymphadenopathy; zoonoses; zoonotic disease.

Figure 1

Average annual incidence (cases/100,000 population) of cat-scratch disease outpatient diagnoses and inpatient admissions by year, United States, 2005–2013.

Figure 2

Geographic distribution of cat-scratch disease by US census division, United States, 2005–2013. Rates are reported as average incidence per 100,000 population per year. During the study period, there were <10 cases in Alaska and <10 cases in Hawaii.

Figure 3

Age- and sex-specific incidence (cases/100,000 population) of cat-scratch disease outpatient diagnoses (A) and inpatient admissions (B), United States, 2005–2013.

Figure 4

Seasonal variation of cat scratch disease outpatient diagnoses and inpatient admissions, United States, 2005–2013.

Figure 5

Seasonal variation of cat-scratch disease diagnoses by region, United States, 2005–2013. Northeast region = New England and Middle Atlantic divisions; North Central = East North Central and West North Central; South = South Atlantic, East South Central, and West South Central; West = Mountain and Pacific (divisions shown in Figure 2).