title: Seroprevalence of antibodies to Rickettsia typhi in the Waikato region of New Zealand.
abstract: The first reported New Zealand-acquired case of murine typhus occurred near Auckland in 1989. Since then, 72 locally acquired cases have been recorded from northern New Zealand. By 2008, on the basis of the timing and distribution of cases, it appeared that murine typhus was escalating and spreading southwards. To explore the presence of Rickettsia typhi in the Waikato region, we conducted a seroprevalence study, using indirect immunofluorescence, Western blot, and cross-adsorption assays of blood donor samples. Of 950 human sera from Waikato, 12 (1·3%) had R. typhi antibodies. The seroprevalence for R. typhi was slightly higher in northern Waikato (1·4%) compared to the south (1·2%; no significant difference, χ 2 P = 0·768 at P < 0·05). Our results extend the reported southern range of R. typhi by 140 km and indicate it is endemic in Waikato. Evidence of past Rickettsia felis infections was also detected in six sera. Globally, R. felis is an emerging disease of concern and this pathogen should also be considered when locally acquired rickettsiosis is suspected. If public health interventions are to be implemented to reduce the risk of rickettsioses as a significant public health problem, improvements in rickettsial diagnostics and surveillance will be necessary.
authors.affiliation: Institute of Environmental Science and Research,Porirua,New Zealand.
authors.forename: M Y
authors.initials: MY
authors.lastname: Lim
authors.affiliation: School of Biological Sciences,University of Adelaide,South Australia,Australia.
authors.forename: P
authors.initials: P
authors.lastname: Weinstein
authors.affiliation: Waikato District Health Board,Hamilton,New Zealand.
authors.forename: A
authors.initials: A
authors.lastname: Bell
authors.affiliation: Institute of Environmental Science and Research,Porirua,New Zealand.
authors.forename: T
authors.initials: T
authors.lastname: Hambling
authors.affiliation: Landcare Research,Dunedin,New Zealand.
authors.forename: D M
authors.initials: DM
authors.lastname: Tompkins
authors.affiliation: Institute of Environmental Science and Research,Porirua,New Zealand.
authors.forename: D
authors.initials: D
authors.lastname: Slaney
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D015153:Blotting, Western; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D009520:New Zealand / Q000453:epidemiology; D012282:Rickettsia Infections / Q000453:epidemiology* / Q000382:microbiology; D041161:Rickettsia felis / Q000302:isolation & purification*; D012286:Rickettsia typhi / Q000302:isolation & purification*; D016036:Seroepidemiologic Studies; D014437:Typhus, Endemic Flea-Borne / Q000453:epidemiology / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial
keywords: Emerging infectious diseases; Rickettsia felis; Rickettsia typhi; murine typhus