Pooling sputum samples to improve the feasibility of Xpert® MTB/RIF in systematic screening for tuberculosis

SETTING

Systematic screening for tuberculosis (TB) using Xpert® MTB/RIF.

OBJECTIVE

To determine whether pooling sputum samples for Xpert testing may improve the feasibility and cost-effectiveness of Xpert by reducing the number of Xpert tests required.

DESIGN

Mycobacterium tuberculosis-spiked sputum samples at low organism concentrations were used to mimic samples that are more likely to be found in the screening, compared to the diagnostic, setting. Using Xpert, pooled sputum samples were tested from a pooling ratio of 1 in 2 to 1 in 12.

RESULTS

A linear relationship between the pooling ratio and the Xpert MTB cycle threshold (Ct) value was found. As the sputum pooling ratio increased, the Ct value also increased. However, the slope of this increase was relatively small. In the majority of the samples pooled (75/96, 78.1%), Xpert was able to detect M. tuberculosis.

CONCLUSION

These findings suggest that sputum pooling may be a viable method of improving the feasibility and cost-effectiveness of large-scale sputum testing using Xpert in the TB screening setting.

Prognosis of sub-types of cancer of unknown primary (CUP) compared to metastatic cancer

21010

Background: The aim is to study the clinical characteristics and outcomes of a complete cohort of presentations of Cancer of Unknown Primary (CUP) compared with patients presenting with metastatic cancer of known primary site. Methods: All persons diagnosed with cancer in New South Wales, Australia, from 1980 to 2004 were studied using a population based cancer registry. Patients classified as CUP were documented, compared to those with initial metastatic presentations of a known primary, for the same period. Results: There were 65,239 histologically or cytologically confirmed metastatic cancers presented. Of these 46,435 (77%) were metastatic with a known primary site and 13,280 (22%) were CUP. The median survival (ms) of all patients presenting with CUP was 3 months compared with 7 months for metastatic cancers of known primary site (p<0.0001). Patients with CUP with adenocarcinoma had significantly worse prognosis compared to metastatic adenocarcinoma of known primary site. However patients with squamous cell CUP had a significantly better outcome (ms 12 months) than metastatic squamous histology with a known primary site (ms 5 months, p<0.0001) with 31% of squamous cell CUP alive at 6 years. For those with CUP and adenocarcinoma the risk of dying was 80% greater compared to those with a known primary and adenocarcinoma (HR 1.8 95%CI 1.7–1.8). For those with CUP and squamous cell carcinoma the risk of dying was 50 % less (HR 0.49 95%CI 0.46–0.53). CUP with small cell, (HR 0.77 95%CI 0.71–0.85) and undifferentiated histology (HR 0.84, 95%CI 0.76–0.93) after controlling for sex and age, had a significantly better prognosis than other metastatic cancers. Germ cell CUP represented only 0.2% of all CUP presentations. Conclusions: CUP is a heterogeneous classification of cancer with a poorer prognosis overall when compared to metastatic cancer of known primary site especially if adenocarcinoma. However, squamous cell and small cell CUP had a better prognosis suggesting a need for specific and more focused treatment. Lack of trends for less CUP presentations compared to reducing metastatic cancer over this 24 year period suggests that CUP is in part a distinct clinico-pathological entity rather than a missed primary diagnosis.

No significant financial relationships to disclose.

Anxiety, post-traumatic stress disorder and depression in Korean War veterans 50 years after the war

BACKGROUND

There has been no comprehensive investigation of psychological health in Australia's Korean War veteran population, and few researchers are investigating the health of coalition Korean War veterans into old age.

AIMS

To investigate the association between war service, anxiety, post-traumatic stress disorder (PTSD) and depression in Australia's 7525 surviving male Korean War veterans and a community comparison group.

METHOD

A survey was conducted using a self-report postal questionnaire which included the PTSD Checklist, the Hospital Anxiety and Depression scale and the Combat Exposure Scale.

RESULTS

Post-traumatic stress disorder (OR 6.63, P<0.001), anxiety (OR 5.74, P<0.001) and depression (OR 5.45, P<0.001) were more prevalent in veterans than in the comparison group. These disorders were strongly associated with heavy combat and low rank.

CONCLUSIONS

Effective intervention is necessary to reduce the considerable psychological morbidity experienced by Korean War veterans. Attention to risk factors and early intervention will be necessary to prevent similar long-term psychological morbidity in veterans of more recent conflicts.

Sesame seed products contaminated with Salmonella: three outbreaks associated with tahini

In November 2002, the first of three outbreaks of Salmonella Montevideo infection in Australia and New Zealand was identified in New South Wales, Australia. Affected persons were interviewed, and epidemiologically linked retail outlets inspected. Imported tahini was rapidly identified as the source of infection. The contaminated tahini was recalled and international alerts posted. A second outbreak was identified in Australia in June-July 2003 and another in New Zealand in August 2003. In a total of 68 S. Montevideo infections, 66 cases were contacted. Fifty-four (82%) reported consumption of sesame seed-based foods. Laboratory analyses demonstrated closely related PFGE patterns in the S. Montevideo isolates from human cases and sesame-based foods imported from two countries. On the basis of our investigations sesame-based products were sampled in other jurisdictions and three products in Canada and one in the United Kingdom were positive for Salmonella spp., demonstrating the value of international alerts when food products have a wide distribution and a long shelf life. A review of the controls for Salmonella spp. during the production of sesame-based products is recommended.

Population-based cancer control: where is the greatest benefit from proven strategies to 'regain' years of life lost prematurely?

OBJECTIVE

To apply a 'health gain' approach to population-based cancer control.

METHOD

We calculated the potential years of life otherwise lost prematurely which could be 'regained' through implementation of cancer control programs for which Level I or Level II evidence already exists for population outcomes.

RESULTS

More potential years of life lost (PYLLs) would be 'regained' by enforcing a 'smoke-free' Australia than by any other possible scenario based on proven effectiveness. Even achievable scenarios for tobacco control (17% or 20% prevalence) would 'regain' more PYLL than either mammographic screening according to national policy or faecal occult blood testing (FOBT) of both men and women over 50 years for colorectal cancer.

CONCLUSIONS

As few commentators remain optimistic that more money will be allocated to health, strategic thinking for health gain needs to re-appraise resource allocation for population-based cancer control in Australia.

IMPLICATIONS

We recommend wider debate in response to our finding that, on the basis of best available evidence, the greatest potential for health gain lies less in cancer screening than fully funded tobacco control.

Outbreak of extended spectrum beta lactamase producing Klebsiella pneumoniae in a neonatal unit

An outbreak of extended spectrum beta lactamase producing Klebsiella pneumoniae (ESBLKp) in a neonatal unit was controlled using simple measures. Normally, the control of such infections can be time consuming and expensive. Seven cases of septicaemia resulted in two deaths. ESBLKp isolates were subtyped by pulsed field gel electrophoresis, and four of the five isolates typed were identical. Control of the outbreak was achieved by altered empiric antibiotic treatment for late onset sepsis and prevention of cross infection by strict attention to hand washing. Widespread colonisation of babies in the unit was presumed, so initial surveillance cultures were not performed. No further episodes of sepsis occurred.

Invasive Haemophilus influenzae type b disease in elderly nursing home residents: two related cases

We investigated two fatal cases of invasive Haemophilus influenzae type b (Hib) infection in a community nursing home in western Sydney, Australia. Two elderly women had lived in the same room, and the onset of their illness was 5 days apart. Hib isolates from blood cultures showed identical profiles by pulsed field gel electrophoresis. These findings suggest that Hib infection was transmitted within this nursing home. Serious Hib disease may be underrecognized in this setting. Continued surveillance and serotyping of invasive H. influenzae disease is essential for identifying groups at increasing risk that may benefit from immunization against Hib.