Cat-scratch disease has a worldwide distribution, however it is a non re portable disease in humans and therefore public health data on this disease is inadequate[1]. Geographical location, present season and variables associated with cats (such as exposure and degree of flea infestation) all play a factor in the prevalence of Cat-scratch disease within a population[2]. In warmer climates, the incidence of Cat-scratch disease is more prevalent during the fall and winter months[2]. The higher rate of Cat-scratch disease during those months may be attributed to the breeding season for adult cats, which allows for the birth of kittens[2]. B henselae, the bacterium responsible for causing Cat-scratch disease, is more prevalent in younger cats [less than one year old] than it is in adult cats[1].
To determine recent incidence of Cat-scratch disease in the United States, the Truven Health MarketScan Commercial Claims and Encounters database was analyzed in a case control study from 2005-2013[3]. The database consisted of healthcare insurance claims for employees, their spouses, and their dependents. All participants were under 65 years of age, from all 50 states. The length of the study period was 9 years and was based off 280,522,578 person-years; factors such as year, length of insurance coverage, region, age, and sex were used to calculate the person-years incidence rate to eliminate confounding variables among the entire study population[3]. 13,273 subjects were diagnosed with Cat-scratch disease, both in and outpatient cases were analyzed. The study revealed an incidence rate of 4.5/100,000 outpatient cases of Cat-scratch disease. For inpatient cases, the incidence rate was much lower at 0.19/100,000 population[3]. Incidence of Cat-scratch disease was highest in 2005 among outpatient cases and then slowly declined. The Southern states saw the most significant decrease of incidence overtime. Mountain regions have the lowest incidence of this disease because fleas are not a common vector found in these areas[3].
Distribution of Cat-scratch disease among children aged 5-9 were of the highest incidence in the analyzed database, followed by woman aged 60-64. Incidence among female patients was higher than that among male patients in all age groups[3]. According to data on social trends, women are more likely to own a cat over men[4]; which supports higher incidence rates of this disease in women. Risk of contracting Cat-scratch disease increases as the number of cats residing in the home increases[1]. The number of pet cats in the United States is estimated to be at 57 million[2]. Due to the large population of cats residing in the United States, the ability of this disease to continue to infect humans is vast. Laboratory diagnosis of Cat-scratch disease has improved in recent years, which may support an increase in incidence of Cat-scratch disease in future populations[2].
- ^ a b c Chomel, Bruno B.; Boulouis, Henri J.; Breitschwerdt, Edward B. (April 15, 2004). "Cat scratch disease and other zoonotic Bartonella infections" (PDF). Vet Med Today: Zoonosis Update. 224 (8): 1270–1279. doi:10.2460/javma.2004.224.1270. PMID 15112775 – via JAVMA.
- ^ a b c d e Windsor, Jeffrey J. (2001). "Cat-scratch Disease: Epidemiology, Etiology, and Treatment" (PDF). British Journal of Biomedical Science. 58 (2): 101–110. PMID 11440202. S2CID 13122848.
- ^ a b c d e Nelson, C. A., Saha, S., & Mead, P. S. (2016). Cat-Scratch Disease in the United States, 2005-2013. Emerging Infectious Diseases, 22(10), 1741-1746. doi:10.3201/eid2210.160115
- ^ "Profile of Pet Owners". Pew Research Center. November 4, 2010. Retrieved November 29, 2017.