Seropositivity of Bartonella henselae Among Suspected Cat Scratch Disease Patients in Malaysia: A 5-Year Retrospective Study (2015-2019).

Cat scratch disease (CSD) is a worldwide preventable zoonotic disease caused by a Gram-negative bacteria, Bartonella henselae (B. henselae). A retrospective study was performed to determine the seroprevalence of B. henselae and to identify its associated factors among cat scratch disease suspected patients in Malaysia from 2015-2019. A total of 3525 serum samples from Malaysian government and private hospitals were tested using an indirect immunofluorescence antibody (IFA) test kit. The IgM seropositivity of B. henselae was 41.8% and this rate showed an increasing trend each year. Among the states, Selangor had the highest B. henselae infection rate (23%), while Perlis had the lowest (1%). Further analysis revealed a significant association between B. henselae infection and female gender, as well as the younger age group between 10-19 years old (AOR 1.20, 95% CI: 1.04, 1.38; AOR 2.84, 95% CI: 2.13, 3.79). Patients presenting with fever, axillary and inguinal lymphadenopathy were found to be at a higher risk of B. henselae infection with AOR 1.73, 95% CI: 1.43, 2.09; AOR 3.71, 95% CI: 2.01, 6.84; AOR 1.91, 95% CI: 1.05, 3.48 respectively. In conclusion, our study demonstrates that B. henselae infection is not uncommon among at-risk patients in Malaysia. Clinicians should have a high level of suspicion when encountering patients with significant clinical presentations and risk factors of CSD.