The Institute of Environmental Science and Research (ESR) has changed its name to the New Zealand Institute for Public Health and Forensic Science (PHF Science) as of 1 July 2025. The website address is now www.phfscience.nz. Visitors are automatically redirected to the new address. Please check and update any links and bookmarks.
Use our research, insights & resources
Our intelligence hub hosts all our information, from disease surveillance dashboards to environmental risk assessments. Explore and use PHF Science’s research, insights, tools and resources to make a difference for Aotearoa New Zealand.
PHF Science is working to actively co-design with Māori in research, science and innovation to improve Māori economic, social and wellbeing outcomes and impacts.
PHF Science is a New Zealand Government owned research organisation that plays a critical national role in public health and forensics, and is a key contributor to environment and biosecurity outcomes.
Members of the genus Rickettsia have garnered much attention worldwide in recent years with the emergence of newly recognized rickettsioses. In New Zealand, only Rickettsia typhi and R. felis, belonging to the typhus and spotted fever groups, respectively, have so far been found (1). R. typhi, primarily transmitted by the oriental rat flea (Xenopsylla cheopis), has a worldwide distribution and causes murine typhus in humans (2). At the end of 2009, a total of 47 cases of murine typhus had been recorded in New Zealand. In contrast, although the cat flea (Ctenocephalides felis) can carry R. felis in New Zealand (3), no human infections have been reported. However, because R. felis shares a similar clinical profile to murine typhus, infection can be mistaken for a suspected case of R. typhi (4). Clinical suspicion of rickettsial infection is widely confirmed by serologic tests with the indirect immunofluorescence assay (IFA) being the standard test. However, antibodies against R. felis in human sera are known to cross-react with R. typhi in IFA (5). Western blot (WB) and crossadsorption assays, in combination with IFA, can differentiate between several rickettsioses (5, 6). We report on the trial in New Zealand of WB and crossadsorption assays for differentiating retrospectively between past R. typhi and R. felis infections and evidence of R. felis infection in persons living in the country.
