Typhus Group Rickettsiosis, Texas, USA, 2003–2013

Abstract

We characterized the epidemiology of typhus group rickettsiosis in Texas, USA. During 2003–2013, a total of 1,762 cases were reported to the state health department. The number of diagnosed cases and geographic expansion increased over time. Physician awareness is critical to diagnose and effectively treat rickettsial infections.

Evidence of locally acquired spotted fever group rickettsioses in Southeast Texas, 2008–2016

“…All of the patients in this study received doxycycline treatment within five days of admission, a fact that likely contributed to positive clinical outcomes (Chapman et al, ). A high level of suspicion for rickettsial disease exists in much of Texas due to the prevalence of R. typhi infection (Murray et al, ); this may have contributed to the relatively timely utilization of doxycycline.…”

Newly Recognized Pediatric Cases of Typhus Group Rickettsiosis, Houston, Texas, USA

“…We identified cases by searching all laboratory orders for rickettsial panel immunofluorescent antibody (IFA) testing. We determined these patients’ case status by following guidance from TXDSHS ( 1 ). We defined a confirmed case as 1 of the following: 1) IFA assay titer > 1:1024 and a titer for R. typhi > 2-fold greater than that for R. rickettsii ; 2) a positive PCR result; or 3) a > 4-fold increase in titer between acute and convalescent specimens.…”

“…Recently, we demonstrated evidence of TGR reemergence into new geographic areas of Texas, including Houston/Harris County, the third most populated county in the United States ( 1 ). Here we present the clinical findings of pediatric patients with TGRs in the Houston metropolitan area, starting in 2011.…”

“…Since 2003, the annual incidence of TGR cases in Texas has increased and expanded geographically ( 1 ). Recently, a study conducted in Galveston County found that 7 of 18 persons with acute fever were positive for R. typhi ( 2 ).…”

“…Recently, a study conducted in Galveston County found that 7 of 18 persons with acute fever were positive for R. typhi ( 2 ). In the Houston/Harris County metropolitan area, which is adjacent to Galveston County, TGR was first reported to the Texas Department of State Health Services (TXDSHS) in 2007 ( 1 ). By 2013, 27 cases had been reported to the state.…”