Investigation of two cases of Mycobacterium chelonae infection in haemato-oncology patients using whole-genome sequencing and a potential link to the hospital water supply.

BACKGROUND: Haemato-oncology patients are at increased risk of infection from atypical mycobacteria such as Mycobacterium chelonae which are commonly found in both domestic and hospital water systems. AIMS: To describe the investigation and control measures following two patient cases of M. chelonae and positive water samples in the study hospital. METHODS: Water testing was undertaken from outlets, storage tanks and mains supply. Whole-genome sequencing (WGS) was used to compare patient and positive water samples. The subsequent infection control measures implemented are described. FINDINGS: The WGS results showed two main populations of M. chelonae within the group of sampled isolates. The results showed that the patient strains were unrelated to each other, but that the isolate from one patient was closely related to environmental samples from water outlets, supporting nosocomial acquisition. CONCLUSIONS: WGS was used to investigate two patient cases of M. chelonae and positive water samples from a hospital water supply. Relevant control measures and the potential for chemical dosing of water systems to enhance proliferation of atypical mycobacteria are discussed.

Ventilator-associated pneumonia surveillance using two methods.

BACKGROUND: Ventilator-associated pneumonia surveillance is used as a quality indicator due to concerns that some cases may be preventable and may contribute to mortality. Various surveillance criteria exist for the purposes of national reporting, but a large-scale direct comparison has not been conducted. METHODS: A prospective cohort study applied two routinely used surveillance criteria for ventilator-associated pneumonia from the European Centre for Disease Control and the American Centers for Disease Control to all patients admitted to two large general intensive care units. Diagnostic rates and concordance amongst diagnostic events were compared. FINDINGS: A total of 713 at-risk patients were identified during the study period. The European surveillance algorithm returned a rate of 4.6 cases of ventilator-associated pneumonia per 1000 ventilation days (95% confidence interval 3.1-6.6) and the American surveillance system a rate of 5.4 (3.8-7.5). The concordance between diagnostic events was poor (Cohen's Kappa 0.127 (-0.003 to 0.256)). CONCLUSIONS: The algorithms yield similar rates, but the lack of event concordance reveals the absence of inter-algorithm agreement for diagnosing ventilator-associated pneumonia, potentially undermining surveillance as an indicator of care quality.

Lessons learned from a pneumocystis pneumonia outbreak at a Scottish renal transplant centre.

BACKGROUND: Pneumocystis pneumonia (PCP) is an opportunistic infection occurring in renal transplant patients. Over a 14-month period an increase in PCP cases was identified among our renal transplant cohort. AIM: The outbreak population was studied to identify potential risk factors for the development of PCP. METHODS: A retrospective analysis of hospital records was carried out, with each case being matched with two case-linked controls. Information was collected on patient demographics, laboratory tests, and hospital visits pre and post development of infection. FINDINGS: No patients were receiving PCP prophylaxis at the time of infection and mean time from transplantation to developing PCP was 4.7 years (range: 0.51-14.5). The PCP group had a significantly lower mean estimated glomerular filtration rate than the control group (29.3 mL/min/1.73 m2 vs 70 mL/min-1 (P = 0.0007)). Three patients were treated for active cytomegalovirus (CMV) infection prior to PCP diagnosis and two had active CMV at the time of diagnosis compared to none in the control group (P = 0.001). Those who developed PCP were more likely to have shared a hospital visit with another patient who went on to develop PCP; 37% of clinic visits vs 19% (P = 0.014). CONCLUSION: This study highlights the ongoing risk of opportunistic infection several years after transplantation and adds weight to potential person-to-person Pneumocystis jirovecii transmission. Risk factors have been identified which may highlight those most at risk, enabling targeted rather than blanket long-term PCP prophylaxis.

Challenges in the diagnosis of leptospirosis outwith endemic settings: a Scottish single centre experience.

Background Leptospirosis is a zoonotic infection occurring worldwide but endemic in tropical countries. This study describes diagnostic testing for leptospirosis at our institution in Scotland over a 10-year period. Method We identified patients with blood samples referred to the Public Health England reference laboratory for leptospirosis testing between 2006 and 2016. Results A total of 480 samples were sent for IgM ELISA testing with 26 positive results from 14 patients. Two patients met criteria for 'confirmed' leptospirosis (microscopic agglutination test > 1:320 in one case and a positive PCR in the other) and the remaining 12 were 'probable' on the basis of IgM ELISA positivity, though 9 did not have microscopic agglutination testing performed. Nine infections were imported, mostly from Asia and with a history of fresh water exposure. Three co-infections (respiratory syncytial virus, influenza B and Campylobacter sp.) were identified. Conclusions Practical issues with microscopic agglutination testing (insufficient blood sent to reference laboratory) and PCR (travellers returning > 7 days after illness onset) represent challenges to the laboratory confirmation of a clinical diagnosis of leptospirosis. Co-infection and infectious/auto-immune causes of false positive serology should be evaluated.

Evaluation of Staphylococcus aureus eradication therapy in orthopaedic surgery.

PURPOSE: Despite WHO recommendations, there is currently no national screening and eradication policy for the detection of methicillin-sensitive Staphylococcus aureus (MSSA) in the UK prior to elective orthopaedic surgery. This study aimed to evaluate the effectiveness of current standard methicillin-resistant S. aureus (MRSA) eradication therapies in the context of S. aureus (both MRSA and MSSA) decolonization in an elective orthopaedic population. METHODOLOGY: A total of 100 patients awaiting joint replacement surgery who were positive for S. aureus on PCR nasal screening underwent the current standard MRSA pre-operative decolonization regimen for 5 days. Prior to commencement of the eradication therapy, swabs of the anterior nares, throat and perineum were taken for culture. Further culture swabs were taken at 48-96 h following treatment, at hospital admission for surgery and at hospital discharge. Following the completion of treatment, patients were asked to provide feedback on their experience using Likert rating scales. The primary outcome of this study was S. aureus clearance 48-96 h following eradication treatment.Results/Key Findings. Clearance of S. aureus 48-96 h following treatment was 94 % anterior nares, 66 % throat and 88 % groin. Mean completion with nasal mupirocin was 98 %. There was no statistically significant recolonization effect between the end of the eradication treatment period and the day of surgery (P>0.05) at a median time of 10 days. CONCLUSION: Current MRSA decolonisation regimens are well tolerated and effective for MSSA decolonization for the anterior nares and groin. The decolonization effect is preserved for at least 10 days following treatment.

Underestimation of Staphylococcus aureus (MRSA and MSSA) carriage associated with standard culturing techniques: One third of carriers missed.

OBJECTIVES: Nasal carriers of Staphylococcus (S.) aureus (MRSA and MSSA) have an increased risk for healthcare-associated infections. There are currently limited national screening policies for the detection of S. aureus despite the World Health Organization's recommendations. This study aimed to evaluate the diagnostic performance of molecular and culture techniques in S. aureus screening, determine the cause of any discrepancy between the diagnostic techniques, and model the potential effect of different diagnostic techniques on S. aureus detection in orthopaedic patients. METHODS: Paired nasal swabs for polymerase chain reaction (PCR) assay and culture of S. aureus were collected from a study population of 273 orthopaedic outpatients due to undergo joint arthroplasty surgery. RESULTS: The prevalence of MSSA nasal colonization was found to be between 22.4% to 35.6%. The current standard direct culturing methods for detecting S. aureus significantly underestimated the prevalence (p = 0.005), failing to identify its presence in approximately one-third of patients undergoing joint arthroplasty surgery. CONCLUSION: Modelling these results to national surveillance data, it was estimated that approximately 5000 to 8000 S. aureus surgical site infections could be prevented, and approximately $140 million to $950 million (approximately £110 million to £760 million) saved in treatment costs annually in the United States and United Kingdom combined, by using alternative diagnostic methods to direct culture in preoperative S. aureus screening and eradication programmes.Cite this article: S. T. J. Tsang, M. P. McHugh, D. Guerendiain, P. J. Gwynne, J. Boyd, A. H. R. W. Simpson, T. S. Walsh, I. F. Laurenson, K. E. Templeton. Underestimation of Staphylococcus aureus (MRSA and MSSA) carriage associated with standard culturing techniques: One third of carriers missed. Bone Joint Res 2018;7:79-84. DOI: 10.1302/2046-3758.71.BJR-2017-0175.R1.

Molecular epidemiology of multi- and extensively-drug-resistant Mycobacterium tuberculosis in Ireland, 2001-2014.

OBJECTIVES: The primary objective of this work was to examine the acquisition and spread of multi-drug resistant (MDR) tuberculosis (TB) in Ireland. METHODS: All available Mycobacterium tuberculosis complex (MTBC) isolates (n = 42), from MDR-TB cases diagnosed in Ireland between 2001 and 2014, were analysed using phenotypic drug-susceptibility testing, Mycobacterial-Interspersed-Repetitive-Units Variable-Number Tandem-Repeat (MIRU-VNTR) genotyping, and whole-genome sequencing (WGS). RESULTS: The lineage distribution of the MDR-TB isolates comprised 54.7% Euro-American, 33.3% East Asian, 7.2% East African Indian, and 4.8% Indo-Oceanic. A significant association was identified between the East Asian Beijing sub-lineage and the relative risk of an isolate being MDR. Over 75% of MDR-TB cases were confirmed in non-Irish born individuals and 7 MIRU-VNTR genotypes were identical to clusters in other European countries indicating cross-border spread of MDR-TB to Ireland. WGS data provided the first evidence in Ireland of in vivo microevolution of MTBC isolates from drug-susceptible to MDR, and from MDR to extensively-drug resistant (XDR). In addition, they found that the katG S315T isoniazid and rpoB S450L rifampicin resistance mutations were dominant across the different MTBC lineages. CONCLUSIONS: Our molecular epidemiological analyses identified the spread of MDR-TB to Ireland from other jurisdictions and its potential to evolve to XDR-TB.

Diagnosis and features of hospital-acquired pneumonia: a retrospective cohort study.

BACKGROUND: Hospital-acquired pneumonia (HAP) is defined as radiologically confirmed pneumonia occurring ≥48h after hospitalization, in non-intubated patients. Empirical treatment regimens use broad-spectrum antimicrobials. AIM: To evaluate the accuracy of the diagnosis of HAP and to describe the demographic and microbiological features of patients with HAP. METHODS: Medical and surgical inpatients receiving intravenous antimicrobials for a clinical diagnosis of HAP at a UK tertiary care hospital between April 2013 and 2014 were identified. Demographic and clinical details were recorded. FINDINGS: A total of 166 adult patients with a clinical diagnosis of HAP were identified. Broad-spectrum antimicrobials were prescribed, primarily piperacillin-tazobactam (57.2%) and co-amoxiclav (12.5%). Sputum from 24.7% of patients was obtained for culture. Sixty-five percent of patients had radiological evidence of new/progressive infiltrate at the time of HAP treatment, therefore meeting HAP diagnostic criteria (2005 American Thoracic Society/Infectious Diseases Society of America guidelines). Radiologically confirmed HAP was associated with higher levels of inflammatory markers and sputum culture positivity. Previous surgery and/or endotracheal intubation were associated with radiologically confirmed HAP. A bacterial pathogen was identified from 17/35 sputum samples from radiologically confirmed HAP patients. These were Gram-negative bacilli (N = 11) or Staphylococcus aureus (N = 6). Gram-negative bacteria tended to be resistant to co-amoxiclav, but susceptible to ciprofloxacin, piperacillin-tazobactam and meropenem. Five of the six S. aureus isolates were meticillin susceptible and all were susceptible to doxycycline. CONCLUSION: In ward-level hospital practice 'HAP' is an over-used diagnosis that may be inaccurate in 35% of cases when objective radiological criteria are applied. Radiologically confirmed HAP represents a distinct clinical and microbiological phenotype. Potential risk factors were identified that could represent targets for preventive interventions.

Efficient national surveillance for health-care-associated infections.

BACKGROUND: Detecting novel healthcare-associated infections (HCAI) as early as possible is an important public health priority. However, there is currently no evidence base to guide the design of efficient and reliable surveillance systems. Here we address this issue in the context of a novel pathogen spreading primarily between hospitals through the movement of patients. METHODS: Using a mathematical modelling approach we compare the current surveillance system for a HCAI that spreads primarily between hospitals due to patient movements as it is implemented in Scotland with a gold standard to determine if the current system is maximally efficient or whether it would be beneficial to alter the number and choice of hospitals in which to concentrate surveillance effort. RESULTS: We validated our model by demonstrating that it accurately predicts the risk of meticillin-resistant Staphylococcus aureus bacteraemia cases in Scotland. Using the 29 (out of 182) sentinel hospitals that currently contribute most of the national surveillance effort results in an average detection time of 117 days. A reduction in detection time to 87 days is possible by optimal selection of 29 hospitals. Alternatively, the same detection time (117 days) can be achieved using just 22 optimally selected hospitals. Increasing the number of sentinel hospitals to 38 (teaching and general hospitals) reduces detection time by 43 days; however decreasing the number to seven sentinel hospitals (teaching hospitals) increases detection time substantially to 268 days. CONCLUSIONS: Our results show that the current surveillance system as it is used in Scotland is not optimal in detecting novel pathogens when compared to a gold standard. However, efficiency gains are possible by better choice of sentinel hospitals, or by increasing the number of hospitals involved in surveillance. Similar studies could be used elsewhere to inform the design and implementation of efficient national, hospital-based surveillance systems that achieve rapid detection of novel HCAIs for minimal effort.

Development of two real-time multiplex PCR assays for the detection and quantification of eight key bacterial pathogens in lower respiratory tract infections.

The frequent lack of a positive and timely microbiological diagnosis in patients with lower respiratory tract infection (LRTI) is an important obstacle to antimicrobial stewardship. Patients are typically prescribed broad-spectrum empirical antibiotics while microbiology results are awaited, but, because these are often slow, negative, or inconclusive, de-escalation to narrow-spectrum agents rarely occurs in clinical practice. The aim of this study was to develop and evaluate two multiplex real-time PCR assays for the sensitive detection and accurate quantification of Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, Moraxella catarrhalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii. We found that all eight bacterial targets could be reliably quantified from sputum specimens down to a concentration of 100 CFUs/reaction (8333 CFUs/mL). Furthermore, all 249 positive control isolates were correctly detected with our assay, demonstrating effectiveness on both reference strains and local clinical isolates. The specificity was 98% on a panel of nearly 100 negative control isolates. Bacterial load was quantified accurately when three bacterial targets were present in mixtures of varying concentrations, mimicking likely clinical scenarios in LRTI. Concordance with culture was 100% for culture-positive sputum specimens, and 90% for bronchoalveolar lavage fluid specimens, and additional culture-negative bacterial infections were detected and quantified. In conclusion, a quantitative molecular test for eight key bacterial causes of LRTI has the potential to provide a more sensitive decision-making tool, closer to the time-point of patient admission than current standard methods. This should facilitate de-escalation from broad-spectrum to narrow-spectrum antibiotics, substantially improving patient management and supporting efforts to curtail inappropriate antibiotic use.

Cutaneous Mycobacterium chelonae infection in Edinburgh and the Lothians, South-East Scotland, U.K.

BACKGROUND: We reviewed all cases of Mycobacterium chelonae infection seen in our department between 1 January 2008 and 31 December 2012. OBJECTIVES: To review the epidemiology, clinical features and management of cutaneous M. chelonae in South-East Scotland, and to compare prevalence data with the rest of Scotland. METHODS: The Scottish Mycobacteria Reference Laboratory database was searched for all cases of cutaneous mycobacterial infections. RESULTS: One hundred and thirty-four cases of cutaneous mycobacterial infection were recorded. Sixty-three were tuberculous; of the remaining 71, M. chelonae was the most common nontuberculous organism (27 cases). National Health Service (NHS) Lothian Health Board was the area with highest incidence in the Scotland (12 cases). Three main groups of patients in the NHS Lothian Health Board contracted M. chelonae: immunosuppressed patients (n = 6); those who had undergone tattooing (n = 4); and others (n = 2). One case is, we believe, the first report of M. chelonae cutaneous infection associated with topical corticosteroid immunosuppression. The majority of patients were treated with clarithromycin monotherapy. CONCLUSION: The most prevalent nontuberculous cutaneous mycobacterial organism in Scotland is M. chelonae. The prevalence of M. chelonae in Edinburgh and the Lothians compared with the rest of Scotland is disproportionately high, possibly owing to increased local awareness and established facilities for mycobacterial studies. Immunosuppression with prednisolone appears to be a major risk factor. The first outbreak of tattoo-related M. chelonae infection in the U.K. has been reported. Clinicians should be aware of mycobacterial cutaneous infection and ensure that diagnostic skin samples are cultured at the optimal temperatures.

The effect of a large Legionnaires' disease outbreak in Southwest Edinburgh on acute and critical care services.

OBJECTIVE: The largest outbreak of Legionnaires Disease (LD) in the UK for a decade occurred in Edinburgh in June 2012. We describe the clinical and public health management of the outbreak. SETTING: Three acute hospitals covering an urban area of ~480,000. METHODS: Data were collected on confirmed and suspected cases and minutes of the Incident Management Team meetings were reviewed to identify key actions. RESULTS: Over 1600 urine samples and over 600 sputum samples were tested during the outbreak. 61 patients with pneumonia tested positive for Legionella pneumophila serogroup 1 by urinary antigen detection, culture, respiratory PCR or serology. A further 23 patients with pneumonia were treated as suspected cases on clinical and epidemiological grounds but had no microbiological diagnosis. 36% of confirmed and probable cases required critical care admission. Mean ICU length of stay was 11.3 (±7.6) days and mean hospital length of stay for those who were admitted to ICU was 23.0 (±17.2) days. For all hospitalized patients the mean length of stay was 15.7 (±14) days. In total there were four deaths associated with this outbreak giving an overall case fatality of 6.5%. Hospital and critical care mortality was 6.1% and 9.1%, respectively. CONCLUSION: A significant proportion of patients required prolonged multiple organ support or complex ventilation. Case fatality compared favourably to other recent outbreaks in Europe. Access to rapid diagnostic tests and prompt antibiotic therapy may have mitigated the impact of pre-existing poor health among those affected.

Combined dysfunctions of immune cells predict nosocomial infection in critically ill patients.

BACKGROUND: Nosocomial infection occurs commonly in intensive care units (ICUs). Although critical illness is associated with immune activation, the prevalence of nosocomial infections suggests concomitant immune suppression. This study examined the temporal occurrence of immune dysfunction across three immune cell types, and their relationship with the development of nosocomial infection. METHODS: A prospective observational cohort study was undertaken in a teaching hospital general ICU. Critically ill patients were recruited and underwent serial examination of immune status, namely percentage regulatory T-cells (Tregs), monocyte deactivation (by expression) and neutrophil dysfunction (by CD88 expression). The occurrence of nosocomial infection was determined using pre-defined, objective criteria. RESULTS: Ninety-six patients were recruited, of whom 95 had data available for analysis. Relative to healthy controls, percentage Tregs were elevated 6-10 days after admission, while monocyte HLA-DR and neutrophil CD88 showed broader depression across time points measured. Thirty-three patients (35%) developed nosocomial infection, and patients developing nosocomial infection showed significantly greater immune dysfunction by the measures used. Tregs and neutrophil dysfunction remained significantly predictive of infection in a Cox hazards model correcting for time effects and clinical confounders {hazard ratio (HR) 2.4 [95% confidence interval (CI) 1.1-5.4] and 6.9 (95% CI 1.6-30), respectively, P=0.001}. Cumulative immune dysfunction resulted in a progressive risk of infection, rising from no cases in patients with no dysfunction to 75% of patients with dysfunction of all three cell types (P=0.0004). CONCLUSIONS: Dysfunctions of T-cells, monocytes, and neutrophils predict acquisition of nosocomial infection, and combine additively to stratify risk of nosocomial infection in the critically ill.

Improving the use of sputum cultures in lower respiratory tract infection.

BACKGROUND: The clinical value of sputum culture in suspected lower respiratory tract infection (LRTI) remains contentious. The quality of samples submitted significantly impacts their clinical usefulness. METHODS: Using pre-defined criteria we prospectively analysed the appropriateness of sputum samples submitted from consecutive patients with suspected LRTI attending two acute hospital units over ten weeks. We then provided an education package for staff on when and how to collect appropriate sputum samples, and repeated the evaluation. RESULTS: Our intervention reduced sample numbers from 347 to 133, simultaneously increasing the proportion of appropriately sent samples from 40.5 to 60.2% (p=0.001) and reducing cost. Appropriate sampling was associated with a higher yield of pathogens (relative risk 1.51, 95% confidence intervals 1.03-2.21, p=0.03). The rate at which sputum samples appeared to alter clinicians' management remained low and constant at 18% pre- and post-intervention. CONCLUSION: A simple educational intervention can significantly increase appropriateness of sputum sampling, reducing workload and cost.

Mycobacterium chelonae infection: a complication of tattooing.

We describe an outbreak of Mycobacterium chelonae infection in four young immunocompetent patients who were tattooed by the same artist. All had been previously tattooed without complication, but following the latest tattooing session, they all developed a very similar papular eruption confined to skin that had been newly coloured light grey. On histological examination of the eruption, granulomatous inflammation with microabscess formation was seen, in association with the tattoo pigment. Skin cultures grown under optimal conditions grew M. chelonae, sensitive to clarithromycin, from one patient. M. chelonae was also cultured from the contents and nozzle of an opened bottle of light-grey ink from the tattoo parlour frequented by the patients. Dermatologists should consider mycobacterial infection in patients who develop inflammatory changes within a new tattoo.

Does an interferon-gamma release assay change practice in possible latent tuberculosis?

BACKGROUND AND AIMS: Suspected latent tuberculosis infection (LTBI) is a common reason for referral to TB clinics. Interferon-gamma release assays (IGRAs) are more specific than tuberculin skin tests (TSTs) for diagnosing LTBI. The aim of this study is to determine if IGRA changes practice in the management of cases referred to a TB clinic for possible LTBI. DESIGN AND METHODS: A prospective study was performed over 29 months. All adult patients who had TST, CXR & IGRA were included. The original decision regarding TB chemoprophylaxis was made by TB team consensus, based on clinical history and TST. Cases were then analysed with the addition of IGRA to determine if this had altered management. An independent physician subsequently reviewed the cases. RESULTS: Of 204 patients studied, 68 were immunocompromised. 120 patients had positive TSTs. Of these, 36 (30%) had a positive QFT and 84 (70%) had a negative QFT. Practice changed in 78 (65%) cases with positive TST, all avoiding TB chemoprophylaxis due to QFT. Of the immunocompromised patients, 17 (25%) underwent change of practice. No cases of active TB have developed. CONCLUSION: This study demonstrates a significant change of clinical practice due to IGRA use. Our findings support the NICE 2011 recommendations.

Tuberculosis and alcohol misuse in Scotland: a population-based study using enhanced surveillance data.

OBJECTIVE: To identify for the first time in Scotland the epidemiological characteristics of tuberculosis (TB) patients who misuse alcohol. DESIGN: A retrospective cohort study using Enhanced Surveillance of Mycobacterial Infections (ESMI) scheme data for adult (aged ≥ 18 years) TB cases notified in Scotland, 2001-2007. Characteristics and treatment outcomes of TB cases with and without recorded alcohol misuse were compared. RESULTS: Of 2419 adult TB cases, alcohol misuse was recorded in 426 (18%). Alcohol misuse was associated with male sex, White ethnicity, birth in the United Kingdom, unemployment, urban residence and socio-economic deprivation. Alcohol misusers were more likely than other TB cases to have pulmonary TB (92% vs. 61%, P < 0.001), be sputum smear-positive (74% vs. 58%, P < 0.001) and be enrolled on directly observed treatment (30% vs. 3%, P < 0.001). Treatment completion rates were respectively 77% and 79% (P = 0.34) in alcohol misusers and other TB cases. CONCLUSION: We have identified epidemiological characteristics associated with alcohol misuse among TB patients in Scotland, notably socio-economic deprivation. We suggest improvements in data collection to allow more robust findings to inform policy decisions to assist the prevention and management of alcohol misuse and reduce the TB incidence in Scotland.

Contact tracing in pulmonary and non-pulmonary tuberculosis.

AIM: The aim of our study was to determine the effectiveness of contact tracing for both pulmonary and non-pulmonary tuberculosis (TB). METHODS: The authors studied contact tracing in South East of Scotland, Edinburgh TB Clinic, UK, for 3 years. New index cases of both pulmonary and non-pulmonary TB were identified from reviewing TB nurses records. Pulmonary involvement was excluded from all non-pulmonary cases. Active TB was diagnosed as per the national TB guidelines. Latent TB was diagnosed based on history, tuberculin skin test and interferon γ release assay. TB contacts were identified from reviewing TB nurses notes on index TB patients. A positive screening episode was defined as identification of either active or latent TB in a contact following relevant investigations. RESULTS: Total number of positive screening episodes for pulmonary TB was 43.1% and non-pulmonary TB was 26.1%. Of these, 78.8% were household contacts and 21.2% were casual contacts. CONCLUSION: Contact tracing in low-prevalence TB countries, for both pulmonary and non-pulmonary TB, is an essential intervention to identify and reduce the number of infected patients that will progress to active disease. This is the key for effective TB control.

Mycobacterium microti infection in two meerkats (Suricata suricatta).

Mycobacterium microti is a member of the Mycobacterium tuberculosis complex (MTC). M. microti is generally considered a pathogen of small rodents, although sporadic infections in a range of other mammals, including domestic animals and man, have been reported. While many human infections have been associated with immunosuppression, an increasing number of cases are being reported in immunocompetent patients. Two cases of M. microti infection in meerkats (Suricata suricatta) are reported. These are the first cases of mycobacterial disease to be described in meerkats outside Africa.