Recurrence of tuberculosis in a low-incidence setting without directly observed treatment: Victoria, Australia, 2002-2014.

SETTING: Victoria, Australia, is an industrialised setting with low tuberculosis (TB) incidence and universal health care. Individually tailored adherence support for self-administered daily anti-tuberculosis treatment is provided. Directly observed treatment (DOT) is very rarely used. OBJECTIVE: To review the rate of recurrent TB in Victoria between 2002 and 2014. DESIGN: This was a retrospective cohort study. All recurrent episodes of TB were reviewed and 24-locus MIRU-VNTR (mycobacterial interspersed repetitive units-variable number of tandem repeats) molecular typing was used where possible to determine the likelihood of relapse or reinfection. RESULTS: Of 4766 notifications, 32 (0.7%) were recurrent episodes. Of 20 episodes that occurred in patients who had previously completed treatment, 11 were culture-positive (0.4% of 3012 culture-positive episodes): 9 were likely relapses (distinguishable at no more than one of 24 loci) and two were likely reinfections, giving a TB relapse rate among culture-positive episodes of 52.5/100 000 person-years (mean time to study end per patient of 5.7 years). The median time until relapse was 18 months (interquartile range 12-30). CONCLUSIONS: The low rate of relapse in our setting demonstrates that individually tailored adherence support for self-administered anti-tuberculosis treatment can achieve excellent treatment outcomes.

Molecular epidemiology of tuberculosis in Victoria, Australia, reveals low level of transmission.

SETTING: Victoria, Australia. OBJECTIVE: To measure the level of Mycobacterium tuberculosis transmission in Victoria. DESIGN: Retrospective analysis of mycobacterial interspersed repetitive unit-variable number of tandem repeats (MIRU-VNTR) typing profiles from all first M. tuberculosis complex (MTC) isolates obtained from patients residing in Victoria from 2003 to 2010 was performed. State TB reference laboratory records were matched with Department of Health notification records to obtain further laboratory, demographic, contact investigation, clinical and treatment data. These data were used to assign patients to one of four categories: 1) no epidemiological link, 2) possible link, 3) likely transmission event and 4) laboratory contamination. RESULTS: A total of 2377 MTC isolates were genotyped using 15-locus MIRU-VNTR. Of the 2298 M. tuberculosis isolates, 1029 (44.8%) had unique genotypic profiles and were considered epidemiologically unrelated, while 1269 (55.2%) isolates shared a profile with one or more other strains, defined as a genotypic cluster. Systematic investigation of all 268 genotypic clusters, including 24-locus MIRU-VNTR on selected isolates, led to a further 862 patients being classified as unrelated, bringing the total number of patients with no epidemiological links to 1891 (82.3%). Of the remaining patients, 294 (12.8%) were classified as having possible epidemiological links, 96 (4.2%) were classified as having known epidemiological links representing likely transmission events and 17 (0.7%) as the result of laboratory cross-contamination. CONCLUSIONS: There is considerable genotypic diversity among Victorian MTC isolates, and the level of transmission is low.

Mycobacterium ulcerans infection in two alpacas.

BACKGROUND: An ulcerative dermopathy caused by Mycobacterium ulcerans is described in two alpacas (Vicugna pacos) domiciled in endemic areas of Victoria, Australia. RESULTS: The diagnosis was confirmed in both cases by PCR targeting the M. ulcerans-specific insertion sequence, IS2404. Extensive wound debridement and bandaging was effective in controlling local disease in one alpaca, although the animal was eventually euthanased because of suspected disease recurrence at other anatomical sites. Treatment was not undertaken in the second animal, but the results of a complete necropsy are described. Investigation of the environs of the second animal yielded low levels of M. ulcerans DNA associated with a variety of samples. The potential use of adjunctive antibiotic therapies directed against M. ulcerans infection in this species is discussed. CONCLUSION: Mycobacterium ulcerans infection should be suspected in alpacas domiciled in endemic areas and presented with ulcerative skin disease.

Epidemiology and control of tuberculosis in Victoria, a low-burden state in south-eastern Australia, 2005-2010.

SETTING: Victoria, Australia. OBJECTIVE: To describe the epidemiology and control of tuberculosis (TB) in Victoria, 2005-2010. DESIGN: Retrospective review of laboratory-confirmed TB in Victoria, 2005-2010. State TB reference laboratory records were matched with Department of Health notification records to obtain laboratory, demographic, clinical and treatment data. RESULTS: The incidence of TB fell in the Australian-born population but increased overall, reflecting an increase in the proportion of overseas-born cases from 88.9% to 95.8% between 2005 and 2010 (P = 0.03). Patients from India and Viet Nam accounted for over one third of all cases. For overseas-born cases, the median time between arrival and diagnosis was 4 years. Half of all diagnoses were pulmonary disease, of which 45.4% were Ziehl-Neelsen smear-positive. Treatment was most commonly self-administered (76.9%), and very few patients defaulted or failed treatment (1.1%). Only 4.1% of cases were linked to another laboratory-confirmed case. Multidrug-resistant TB remained uncommon (1.7% of cases). CONCLUSIONS: TB in Victoria remains low by global standards and continues to overwhelmingly affect the overseas-born population. Current TB control strategies in Victoria are effective, but strengthened control in high-burden countries will also improve TB control locally.

Long-term follow-up of contacts exposed to multidrug-resistant tuberculosis in Victoria, Australia, 1995-2010.

SETTING: The effectiveness of public health strategies following exposure to multidrug-resistant tuberculosis (MDR-TB) is not clear. OBJECTIVE: To perform long-term follow-up of MDR-TB contacts and review individual outcomes and management approaches. DESIGN: Retrospective review of MDR-TB contacts identified by the Victorian Department of Health from 1995 to 2010. Health records, including personal medical and pharmacy records and statewide clinical and laboratory TB databases, were searched to identify management strategies and individual outcomes. RESULTS: A total of 570 contacts of 47 MDR-TB cases were identified, with a total follow-up period of 3093 person-years of observation (PYO) since exposure. Of 570 contacts, 49 (8.6%) were considered likely to have been infected with Mycobacterium tuberculosis from index cases, and 11/49 (22.5%) of these were prescribed preventive therapy tailored to isolate susceptibility. No MDR-TB cases occurred in those receiving preventive treatment, while two cases were observed in those not treated (incidence 2878/100 000 PYO during the first 2 years post exposure). CONCLUSIONS: The risk of MDR-TB transmission to close contacts in this low-prevalence setting highlights the potential for public health strategies involving preventive treatment.

Localised Mycobacterium ulcerans infection in four dogs.

Localised infection caused by Mycobacterium ulcerans is described in two Kelpies, a Whippet and a Koolie domiciled on the Bellarine Peninsula, Victoria, Australia. The diagnosis was confirmed using real-time polymerase chain reaction (PCR) targeting the M. ulcerans-specific insertion sequence (IS2404) in DNA extracted from swabs of ulcerated lesions in all cases. Where available, molecular typing confirmed that three of the dogs were infected with a strain of M. ulcerans that was indistinguishable from a disease-causing strain in people and other animals in Victoria. One dog was still undergoing treatment at the time of writing, but the remaining three dogs were successfully treated with a combination of surgical debridement and medical therapy in one case, and medical therapy alone in the other two. Investigation of the home environs of three of the dogs using real-time PCR revealed low amounts of M. ulcerans DNA in various environmental samples. Mycobacterium ulcerans infection should be included in the differential diagnoses of any ulcerated skin lesions in dogs that live in or visit endemic areas of Victoria and Queensland.

Molecular characterization of a novel fastidious mycobacterium causing lepromatous lesions of the skin, subcutis, cornea, and conjunctiva of cats living in Victoria, Australia.

Between 1999 and 2006, 15 cats were diagnosed with disease attributable to a novel mycobacterial species. The infections consisted of granulomatous lesions in the skin, subcutis, and ocular or periocular tissues with an indolent but progressive clinical course. Lesions typically were found in facial regions or on the distal limbs. Cats of all ages and both sexes were affected. Infections often were challenging to treat, although they could be cured using surgery in concert with combination antimicrobial therapy. Microscopically, lesions were granulomatous to pyogranulomatous and contained numerous acid-fast bacilli. Scanty cultures of the causal microorganisms occasionally could be obtained in mycobacterial broth, but subculture to solid media failed. When cultures were not available, DNA was extracted from fresh tissue, lyophilized material, and formalin-fixed, paraffin-embedded tissues from lesions. PCR amplification of the 5' end of the 16S rRNA gene and regions within four additional loci (ITS1, hsp65, rpoB, and sodA) was performed with various efficiencies using mycobacterial primers. Nucleotide sequences were unique for each locus tested. Nucleotide sequences obtained from individual cases were identical for each locus for which the amplification was successful. Phylogenetic analysis performed using concatenated partial 16S rRNA and hsp65 gene sequences indicated that this novel mycobacterial species from Victoria is a member of the Mycobacterium simiae-related group, taxonomically related to the mycobacterium causing leproid granulomas in dogs throughout the world. Based on the clustering of cases, we refer to this novel species as Mycobacterium sp. strain Tarwin.

A new trichrome-blue stain for detection of microsporidial species in urine, stool, and nasopharyngeal specimens.

Detection of microsporidia in clinical specimens has relied on electron microscopy, histology, or staining. This article describes further alterations to the modified trichrome staining method which make it easier to identify microsporidial spores. The changes are a decrease in the phosphotungstic acid level and the substitution of a colorfast counterstain, aniline blue, for the fast green of the original stain. The modified stain provides good contrast between microsporidial spores and background material including human and fungal cells. Stool specimens from 139 human immunodeficiency virus-seropositive patients revealed that 5 patients were infected with Enterocytozoon bieneusi and 6 patients had larger spores. Thin-section electron microscopy of the larger spores showed a structure consistent with that of either Encephalitozoon or Septata species. Three of the patients with Encephalitozoon- or Septata-like species had disseminated infection, with spores detected in nasopharyngeal aspirates and urine samples.