ABSTRACT
Buruli ulcer (BU) occurs in >30 countries. The causative organism, Mycobacterium ulcerans, is acquired from the environment, but the exact mode of transmission is unknown. We investigated an outbreak of BU in a small coastal town in southeastern Australia and screened by PCR mosquitoes caught there. All cases of BU were confirmed by culture or PCR. Mosquitoes were trapped in multiple locations during a 26-month period. BU developed in 48 residents of Point Lonsdale/Queenscliff and 31 visitors from January 2001 through April 2007. We tested 11,504 mosquitoes trapped at Point Lonsdale (predominantly Aedes camptorhynchus). Forty-eight pools (5 species) were positive for insertion sequence IS2404 (maximum likelihood estimate 4.3/1,000), and we confirmed the presence of M. ulcerans in a subset of pools by detection of 3 additional PCR targets.
Subject(s)
Buruli Ulcer/epidemiology , Culicidae/microbiology , Disease Outbreaks , Insect Vectors/microbiology , Mycobacterium ulcerans/isolation & purification , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Australia/epidemiology , Buruli Ulcer/microbiology , Child , Child, Preschool , Communicable Diseases, Emerging/epidemiology , Communicable Diseases, Emerging/microbiology , Environmental Microbiology , Female , Humans , Infant , Male , Middle Aged , Mycobacterium ulcerans/genetics , Polymerase Chain Reaction/methodsABSTRACT
This report describes the epidemiological and clinical features of an outbreak of 47 cases of laboratory-confirmed Barmah Forest virus disease (BF disease) that occurred in Victoria between January and May 2002. Laboratory-confirmed cases were investigated, and information on travel history and clinical details was collected. Surveillance data from adult mosquito trappings and climatic conditions in the Wellington Shire were also reviewed. The response rate for interviews was 85 per cent (40/47). The most common symptoms reported by cases included arthralgia (95%), lethargy (90%) and maculopapular rash (72.5%). Transmission of BF disease in the Gippsland region was associated with unusually high numbers of Ochlerotatus camptorhynchus mosquitoes. This outbreak was of interest due to the fact that cases of BF disease outnumbered cases of Ross River virus disease (RR disease) in Victoria for the first time since data were available. Similar outbreaks of BF disease, in the absence of RR disease, occurred in Western Australia in 1993 and New South Wales in 1994/1995. Although the majority of BF disease cases reported regular outdoor activity during which they could be exposed to mosquito populations, they infrequently take precautions to limit exposure. Further efforts need to be made to educate people of the importance of using repellents and other personal preventative measures.
