Evaluating the Use of a Streptococcus pneumoniae Urinary Antigen Detection Kit for the Management of Community-Acquired Pneumonia in Japan

Diagnostic accuracy of urinary antigen tests for pneumococcal pneumonia among patients with acute respiratory failure suspected pneumonia: a systematic review and meta-analysis

BACKGROUND/OBJECTIVES

Urinary antigen tests have been used for the rapid identification of Streptococcus pneumoniae infection in patients with pneumonia, thereby leading to earlier targeted therapy than when using conventional diagnostic culture methods. This study aimed to update the knowledge on the diagnostic accuracy of urinary antigen tests for S. pneumoniae among patients with acute respiratory failure suspected of pneumonia based on a systematic review and meta-analysis.

METHODS

A systematic search was performed using MEDLINE and the Cochrane Central Register of Controlled Trials for studies published up to 3 June 2020. Prospective and retrospective cohort studies (in English) that reported on the diagnostic performance of urinary antigen tests versus culture or smear diagnostic methods in adult patients with clinically diagnosed pneumonia were selected and analysed. The QUADAS-2 tool was used to assess the risk of bias, and a bivariate random effects model was applied to perform a meta-analysis of the selected studies.

RESULTS

A total of 2179 studies were screened, of which 30 met the eligibility criteria for quality assessment and meta-analysis. Overall, data from 12 366 patients, including 1548 patients (12.5%) with the target condition and suspected pneumococcal pneumonia, were included in the analysis. The overall quality of the included studies was determined to be serious. The calculated pooled sensitivity and specificity were of 0.66 (95% CI 0.62 to 0.69) and 0.90 (95% CI 0.85 to 0.93), respectively.

CONCLUSIONS

The urinary antigen test is useful for achieving a definitive diagnosis of S. pneumoniae infection in patients with pneumonia.

Burden of illness associated with pneumococcal infections in Japan - a targeted literature review

INTRODUCTION

Pneumococcal diseases (PDs) are among the leading causes of mortality and morbidity worldwide. However, the evidence on epidemiology, health economic, and patient-reported outcomes has not been systematically reviewed and published in Japan. This study aimed to assess the burden, treatment adherence and compliance, and serotype distribution associated with PDs in Japan.

METHOD

One hundred and eight studies were identified between January 2005 and June 2020. The identified studies were mostly regional and with a limited scale, clinical settings, and populations.

RESULTS

In 2013-2017, invasive PD incidence rates were 4.98-9.47/100,000 in <4-year-olds, 0.36/100,000 in 5-14-year-olds, 0.46/100,000 in 15-64-year-olds, and 1.50-5.38/100,000 in the elderly. The incidence of invasive PDs in children decreased from 24.6/100,000 in 2008 to 10.7/100,000 in 2013 after the introduction of PCV7 and further declined to 10.3/100,000 in 2014 after PCV13 was introduced. From 2014, the prevalence of PCV13 serotypes decreased across all age groups along with a decrease of PPV23 serotypes, but an increase of PPV23 serotypes not included in PCV13 among adults and the elderly. No study reported health-related quality-of-life data for PDs. In children, direct costs were 340,905-405,978 JPY (3,099-3,691 USD) per pneumococcal bacteraemia, 767,447-848,255 JPY (6,977-7,711 USD) per pneumococcal meningitis, and 79,000 JPY (718 USD) per pneumococcal acute otitis media episodes. In adults and the elderly, the direct cost of pneumococcal pneumonia was 348,280-389,630 JPY (3,166-3,542 USD). The average hospital stay length was 7.2-31.9 days in children, 9.0 days in adults and 9.0-28.7 days in adults and the elderly.

CONCLUSIONS

The epidemiological burden of PDs remains high in Japan, especially among children and the elderly with invasive PDs accounting for a very small proportion of all PDs. A significant impact of the PCV13 vaccine program was reported, while the PPV23's impact remains unclear. A substantial decrease in quality-adjusted life years in adults and the elderly and a high economic burden may exist.

Atypical pneumonia: Pathophysiology, diagnosis, and treatment

Atypical pneumonia is caused by atypical pathogens that are not detectable with Gram stain and cannot be cultured using standard methods. The most common causative organisms of atypical pneumonia are Mycoplasma pneumoniae, Chlamydia pneumoniae, and Legionella species. The therapeutic approach for atypical pneumonias is different than that for typical pneumonia. Typical bacterial pathogens classically respond to β-lactam antimicrobial therapy because they have a cell wall amenable to β-lactam disruption. On the contrary, most atypical pathogens do not have a bacterial cell wall, some are intracellular (e.g., Legionella), and some are paracellular (e.g., M. pneumoniae). To prevent an increase in the number of antimicrobial-resistant strains, the Japanese pneumonia guidelines have proposed a differential diagnosis for typical bacterial pneumonia and atypical pneumonia to select an appropriate antibiotic for the management of mild-to-moderate pneumonia. The guidelines have set up six parameters and criteria based on the clinical symptoms, physical signs, and laboratory data. However, in the elderly individuals and patients with underlying diseases, the differential diagnosis may be difficult or a mixed infection may be latent. Therefore, in these individuals, the administration of a β-lactam drug plus a macrolide or tetracycline, or only fluoroquinolone should be considered from the beginning to cover bacterial and atypical pneumonia.

Predictors and usefulness of targeted therapy for pneumococcal community-acquired pneumonia diagnosed by the urinary antigen test: a prospective, observational cohort study

The aim of the present study was to investigate the predictors of targeted therapy (TT) for pneumococcal community-acquired pneumonia (PCAP) with a positive urinary antigen test (UAT) and compare the outcomes with those of nontargeted therapy. This prospective cohort study enrolled consecutive PCAP patients with a positive UAT who were hospitalized at Kurashiki Central Hospital from October 2010 to November 2019. A total of 286 patients were included. Of them, 56 patients (19.6%) were included in the TT group. On multivariate analysis, identification of Gram-positive diplococci by Gram stain (OR [95% CI]: 2.46 [1.32-4.63]) was a positive predictor, whereas aspiration pneumonia (0.17 [0.03-0.59]) and CURB-65 score (0.59 [0.42-0.81]) were negative predictors of TT. Initial treatment failure and 30-day mortality were not significantly different. The UAT is not used enough for TT, and TT for PCAP did not have worse outcomes.

Evaluating the utility of Binax NOW Streptococcus pneumoniae urinary antigen test in adults with community acquired pneumonia in China

INTRODUCTION

Binax NOW rapid immunochromatographic membrane test (ICT), a rapid method for detection of Streptococcus pneumoniae antigen, has been used widely in Europe and America, but rarely in China.

OBJECTIVE

Our aim is to evaluate the utility of the ICT among adult patients with community acquired pneumonia (CAP) in China.

METHODS

Adult patients with CAP were prospectively recruited from 12 general hospitals. ICT tests were done in all patients and clinical data were recorded. Qualified sputum culture was used as the standard for determining the diagnostic usefulness of ICT test.

RESULT

Thousand hundred fifty four CAP patients were enrolled in analysis, with median (IQR) age of 48 (35) years. 276 (23.9%) patients had underling diseases, 770 (66.7%) had received antibiotics before ICT test. Overall, the positive rate of ICT test was 3.3%, with sensitivity and specificity 57.9% and 96.6%, respectively. Disease severity, chronic obstructive pulmonary disease (COPD), increased age; respiratory rate (RR), neutrophil ratio, blood urea nitrogen (BUN), procalcitonin (PCT) and the decreased oxygenation index were associated with positive results of ICT tests. Patients with BUN >7 mmol/L, CURB-65 3-5, PCT > 2ng/mL were the top three groups with highest positive rate of ICT test (22.6%, 22.2% and 21.1% respectively).

CONCLUSION

ICT test has a moderate sensitivity and high specificity in adults with CAP in China. Patients classified as sever pneumonia, or those with BUN > 7 mmol/L, or PCT > 2 ng/mL are more likely to have positive results.

Usefulness of pneumococcal antigen urinary testing in the intensive care unit?

OBJECTIVES

The use of pneumococcal antigen urinary tests is substantially increasing and is associated with a significant cost. The relevant use of this test in the intensive care unit (ICU) should be better defined. Our aim was to define the role of this test in relation to other microbiological tests. We described a series of patients admitted to the ICU for an invasive pneumococcal disease (IPD).

PATIENTS AND METHODS

We conducted a retrospective and descriptive study of the microbiological tests used to diagnose IPD in patients admitted to the ICU of the University Hospital in Bordeaux. Our aim was to measure the sensitivity of these bacteriological tests and of the BinaxNOWS. pneumoniae test.

RESULTS

Between 2009 and 2013, 148 patients were admitted for an IPD. A lower respiratory tract infection was diagnosed in 96.6% of them (143 patients). The overall ICU case fatality rate was 17.6%. The sensitivity of the pneumococcal antigen urinary test, sputum bacteriological examination, and blood cultures was respectively 83%, 37.6%, and 29.7%. S. pneumoniae was isolated from at least one bacteriological sample in 48.6% of patients, but in 51.4%, the diagnosis was only based on the results of the pneumococcal antigen urinary test.

CONCLUSION

We suggest performing a pneumococcal antigen urinary test when an IPD is suspected, only if the bacteriological tests are still negative after 48hours. This strategy would result in a substantial cost saving. Patients would not face any additional risks as the result of the pneumococcal antigen urinary test does not have any impact on the initially prescribed antibiotic therapy.

Clinical factors associated with negative urinary antigen tests implemented for the diagnosis of community-acquired pneumococcal pneumonia in adult patients

OBJECTIVE

This study investigated clinical factors associated with negative urinary antigen tests (UAT) implemented for the diagnosis of pneumococcal community-acquired pneumonia (CAP) in adult patients.

SUBJECTS AND METHODS

We reviewed the medical records of 755 adult patients who completed the UAT in our hospital between 2009 and 2012. Of these, we evaluated 63 patients with bacteriologically confirmed definite pneumococcal CAP (33 were UAT-positive, and 30 were UAT-negative).

RESULTS

There was no significant difference between the UAT-positive and the UAT-negative patients regarding age, dehydration, respiratory failure, orientation, blood pressure (ADROP) score (the CAP severity score proposed by the Japanese Respiratory Society), gender, white blood cell counts, liver/kidney function tests, or urinalysis. However, serum C-reactive protein (CRP) concentrations were 31% lower in the UAT-negative patients than in the UAT-positive patients (p = 0.02). Furthermore, the prothrombin time-international normalized ratio was 50% higher in the UAT-negative patients than in the UAT-positive patients, although the difference did not reach statistical significance (p = 0.06). The prevalence of comorbidities was similar in both UAT-positive and UAT-negative patients. However, warfarin had been prescribed in 8 (27%) of the UAT-negative patients compared to only 1 (3%) of the UAT-positive patients (odds ratio = 11.6; p = 0.01).

CONCLUSIONS

These results suggested that low serum CRP concentrations and the use of warfarin increased the possibility with which false-negative UAT results occurred in these patients with pneumococcal CAP.

The role of rapid diagnostic tests in managing adults with pneumonia in low-resource settings

In well-resourced settings the systematic use of rapid diagnostics tests (e.g. pneumococcal urinary antigen test) that define the causal pathogen to direct therapy has not resulted in significantly improved outcomes in adults withpneumonia. The management of pneumonia in many low-resource settings is complicated by a substantial burden of tuberculosis and HIV-associated opportunistic infections, in addition to the usual spectrum of pathogens seenin well-resourced settings. Clinical features alone do not reliably distinguish between these different aetiologiesand physicians often have to treat empirically. Given the limitations in diagnostic laboratory capability present inmost low-resource settings, rapid and point-of-care diagnostic tests could become valuable tools to guide treatment decisions. Pneumococcal and Legionella urinary antigen tests are specific and moderately sensitive, but their utilityin low-resource settings is uncertain. The Xpert MTB/RIF (Cepheid, USA) platform and rapid assays for urinary lipoarabinomannan can substantially speed up tuberculosis diagnosis; the current challenge is to translate this intoearlier treatment and hopefully improve patient outcome. In HIV-infected patients, 1-3-β-D-glucan is a serum marker of Pneumocystis jirovecii infection with excellent sensitivity. Further studies are needed to assess the clinical utilityand cost-effectiveness of these rapid diagnostic assays when they are incorporated into treatment algorithms.

Systematic review and meta-analysis of a urine-based pneumococcal antigen test for diagnosis of community-acquired pneumonia caused by Streptococcus pneumoniae

Standard culture methods for diagnosis of Streptococcus pneumoniae pneumonia take at least 24 h. The BinaxNOW urine-based test for S. pneumoniae (BinaxNOW-SP) takes only 15 min to conduct, potentially enabling earlier diagnosis and targeted treatment. This study was conducted to assess whether the use of BinaxNOW-SP at the time of hospital admission would provide adequate sensitivity and specificity for diagnosis of community-acquired pneumonia (CAP) in adult patients. We searched PubMed, EMBASE/OVID, Cochrane Collaboration, Centre for Reviews and Dissemination, INAHTA, and CADTH for diagnostic or etiologic studies of hospitalized predominately adult patients with clinically defined CAP that reported the diagnostic performance of BinaxNOW-SP versus cultures. Two authors independently extracted study details and diagnostic two-by-two tables. We found that 27 studies met our inclusion criteria, and three different reference standards were used between them. A bivariate meta-analysis of 12 studies using a composite of culture tests as the reference standard estimated the sensitivity of BinaxNOW-SP as 68.5% (95% credibility interval [CrI], 62.6% to 74.2%) and specificity as 84.2% (95% CrI, 77.5% to 89.3%). A meta-analysis of all 27 studies, adjusting for the imperfect and variable nature of the reference standard, gave a higher sensitivity of 74.0% (CrI, 66.6% to 82·3%) and specificity of 97.2% (CrI, 92.7% to 99.8%). The analysis showed substantial heterogeneity across studies, which did not decrease with adjustment for covariates. We concluded that the higher pooled sensitivity (compared to culture) and high specificity of BinaxNOW-SP suggest it would be a useful addition to the diagnostic workup for community-acquired pneumonia. More research is needed regarding the impact of BinaxNOW-SP on clinical practice.

Estimating the burden of pneumococcal pneumonia among adults: a systematic review and meta-analysis of diagnostic techniques

Background

Pneumococcal pneumonia causes significant morbidity and mortality among adults. Given limitations of diagnostic tests for non-bacteremic pneumococcal pneumonia, most studies report the incidence of bacteremic or invasive pneumococcal disease (IPD), and thus, grossly underestimate the pneumococcal pneumonia burden. We aimed to develop a conceptual and quantitative strategy to estimate the non-bacteremic disease burden among adults with community-acquired pneumonia (CAP) using systematic study methods and the availability of a urine antigen assay.

Methods and Findings

We performed a systematic literature review of studies providing information on the relative yield of various diagnostic assays (BinaxNOW® S. pneumoniae urine antigen test (UAT) with blood and/or sputum culture) in diagnosing pneumococcal pneumonia. We estimated the proportion of pneumococcal pneumonia that is bacteremic, the proportion of CAP attributable to pneumococcus, and the additional contribution of the Binax UAT beyond conventional diagnostic techniques, using random effects meta-analytic methods and bootstrapping. We included 35 studies in the analysis, predominantly from developed countries. The estimated proportion of pneumococcal pneumonia that is bacteremic was 24.8% (95% CI: 21.3%, 28.9%). The estimated proportion of CAP attributable to pneumococcus was 27.3% (95% CI: 23.9%, 31.1%). The Binax UAT diagnosed an additional 11.4% (95% CI: 9.6, 13.6%) of CAP beyond conventional techniques. We were limited by the fact that not all patients underwent all diagnostic tests and by the sensitivity and specificity of the diagnostic tests themselves. We address these resulting biases and provide a range of plausible values in order to estimate the burden of pneumococcal pneumonia among adults.

Conclusions

Estimating the adult burden of pneumococcal disease from bacteremic pneumococcal pneumonia data alone significantly underestimates the true burden of disease in adults. For every case of bacteremic pneumococcal pneumonia, we estimate that there are at least 3 additional cases of non-bacteremic pneumococcal pneumonia.

Regional epidemiology of invasive pneumococcal disease in Asian adults: epidemiology, disease burden, serotype distribution, and antimicrobial resistance patterns and prevention

OBJECTIVES

To summarize published data on the clinical and economic burden, epidemiology, antimicrobial resistance levels, serotype prevalence, and prevention strategies for pneumococcal disease among adults in Asia.

METHODS

We performed a systematic search of the PubMed database for relevant, peer-reviewed articles published between January 1995 and December 2011, covering China, Hong Kong, India, Indonesia, Japan, Malaysia, Pakistan, the Philippines, Singapore, South Korea, Taiwan, Thailand, and Vietnam.

RESULTS

Taiwan and Thailand had the most comprehensive epidemiological data on adult pneumococcal disease. Very little relevant data were found for Indonesia, Pakistan, the Philippines, and Vietnam; surveillance is urgently needed in these countries. The emergence and spread of resistance emphasize the importance of vaccination to prevent infection in adults at increased risk for serious pneumococcal disease. Vaccination policies and opinions on the efficacy of vaccination vary widely in Asian countries, although a new option in the form of a pneumococcal conjugate vaccine is now available.

CONCLUSIONS

Increased awareness of the public health and economic benefits of pneumococcal vaccination is critically needed to help both the public and policymakers in making changes to vaccination policies in the region. Maximizing access to pneumococcal vaccines will decrease the number of hospitalizations, complications, and deaths associated with pneumococcal disease.

Guidelines for the management of adult lower respiratory tract infections--summary

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Guidelines for the management of adult lower respiratory tract infections--full version

This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. Background sections and graded evidence tables are also included. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.

Routine use of point-of-care tests: usefulness and application in clinical microbiology

Point-of-care (POC) tests offer potentially substantial benefits for the management of infectious diseases, mainly by shortening the time to result and by making the test available at the bedside or at remote care centres. Commercial POC tests are already widely available for the diagnosis of bacterial and viral infections and for parasitic diseases, including malaria. Infectious diseases specialists and clinical microbiologists should be aware of the indications and limitations of each rapid test, so that they can use them appropriately and correctly interpret their results. The clinical applications and performance of the most relevant and commonly used POC tests are reviewed. Some of these tests exhibit insufficient sensitivity, and should therefore be coupled to confirmatory tests when the results are negative (e.g. Streptococcus pyogenes rapid antigen detection test), whereas the results of others need to be confirmed when positive (e.g. malaria). New molecular-based tests exhibit better sensitivity and specificity than former immunochromatographic assays (e.g. Streptococcus agalactiae detection). In the coming years, further evolution of POC tests may lead to new diagnostic approaches, such as panel testing, targeting not just a single pathogen, but all possible agents suspected in a specific clinical setting. To reach this goal, the development of serology-based and/or molecular-based microarrays/multiplexed tests will be needed. The availability of modern technology and new microfluidic devices will provide clinical microbiologists with the opportunity to be back at the bedside, proposing a large variety of POC tests that will allow quicker diagnosis and improved patient care.

[Assessment of the contribution of the immunochromatographic pneumococcal urinary antigen test to the etiological diagnosis of pneumonia in hospitalized adults]

AIM OF THE STUDY

To assess the usefulness and prescription practices of the Binax Now Streptococcus pneumoniae urinary antigen test in hospitalized adults.

PATIENTS AND METHODS

The results of the pneumococcal urinary antigen tests (UAT) performed from January 2002 to September 2004 were related to that of microbiological cultures, and in positive patients to radiographic findings and C-reactive protein (CRP) levels. The evolution of the number of prescriptions and positivity rate in 2007 versus 2002-2004 was analyzed.

RESULTS

The pneumococcal UAT was positive in 32 of the 278 patients included from 2002 to 2004 (11.5%). Results were concordant with that of microbiological cultures in 90% of the 247 documented cases. Pneumococcal etiology was considered to be definite in 19 patients (isolation of S. pneumoniae from blood, 17 patients; or pleural fluid, two patients), of whom 15 had a positive UAT (sensitivity: 79%); to be probable in 22 patients (positive UAT, 17 patients and/or isolation of S. pneumoniae from respiratory samples, six patients), and was retained in 39 of the 41 patients (positive predictive value: 93.7%). CRP was greater than 100mg/L in 34 of 39 documented patients and lobar alveolar radiographic opacities observed in 25 of 28 documented patients. In 2007, the dramatic increase in the number of UAT prescriptions and the diversification of prescribing units were associated to a decreased positivity rate (8.1%).

CONCLUSION

Whereas the pneumococcal UAT clearly increases etiological diagnosis, pneumococcal pneumonia cannot be ruled out if negative. Indications for its use need to be refined to improve the cost-effectiveness of this test.

Diagnosis of Streptococcus pneumoniae infections in adults with bacteremia and community-acquired pneumonia: clinical comparison of pneumococcal PCR and urinary antigen detection

The diagnosis of severe Streptococcus pneumoniae infection relies heavily on insensitive culture techniques. To improve the usefulness of PCR assays, we developed a dual-PCR protocol (targeted at pneumolysin and autolysin) for EDTA blood samples. This was compared to the Binax NOW S. pneumoniae urine antigen test in patients with bacteremic pneumococcal infections. Patients with nonbacteremic community-acquired pneumonia also were tested by these methods to determine what proportion could be confirmed as pneumococcal infections. A direct comparison was made in a group of patients who each had both tests performed. The Binax NOW S. pneumoniae urine antigen test was positive in 51 of 58 bacteremic pneumococcal cases (sensitivity, 88%; 95% confidence interval [CI], 77 to 95%), whereas the dual PCR was positive in 31 cases (sensitivity, 53.5%; 95% CI, 40 to 67%; P < 0.0001), and all of these had detectable urinary antigens. Both tests gave positive results in 2 of 51 control patients (referred to as other-organism septicemia), giving a specificity of 96% (95% CI, 86.5 to 99.5%). In 77 patients with nonbacteremic community-acquired pneumonia, urinary antigen was detected significantly more often (in 21 patients [27%]) than a positive result by the dual-PCR protocol (6 [8%]) (P = 0.002). The development of a dual-PCR protocol enhanced the sensitivity compared to that of the individual assays, but it is still significantly less sensitive than the Binax NOW urine antigen test, as well as being more time-consuming and expensive. Urinary antigen detection is the nonculture diagnostic method of choice for patients with possible severe pneumococcal infection.

Early diagnosis of lower respiratory tract infections (point-of-care tests)

PURPOSE OF REVIEW

Respiratory tract infections are a common reason for prescribing antibiotics, although not all of these infections require such therapy. Rapid diagnosis of etiology using point-of-care tests is a potentially useful way of reducing prescriptions of both unnecessary and unnecessarily broad-spectrum antibiotics. This can also lead to the facilitation of appropriate infection control measures to prevent spread of respiratory viruses within institutions.

RECENT FINDINGS

Point-of-care tests are available for diagnosing influenza, respiratory syncytial virus, Streptococcus pneumoniae, and Legionella infections using easily obtainable specimens. Their main benefit is that results can be obtained in about 15 min with reasonable accuracy. In many situations, however, it is still important to confirm diagnosis with more accurate but slower tests such as bacterial cultures with antibacterial susceptibility testing or viral polymerase chain reaction testing.

SUMMARY

Although the sensitivities of many of the rapid diagnostic tests are moderate, when used at the time of initial consultation, they have the potential to reduce costs, length of stay, secondary spread of respiratory viruses, and inappropriate antibiotic prescribing.

Additive inoculation of influenza vaccine and 23-valent pneumococcal polysaccharide vaccine to prevent lower respiratory tract infections in chronic respiratory disease patients

BACKGROUND

An increased incidence of pneumococcal infection triggered by influenza infection has been reported.

OBJECTIVE

To examine the effectiveness of the additive inoculation of influenza vaccine (I-V) and 23-valent pneumococcal vaccine (P-V) to prevent lower respiratory tract infections.

METHODS

105 Japanese patients with chronic respiratory disease underwent the additive inoculation of I-V and P-V between October 2002 and January 2003, and their medical records were used to retrospectively examine the number of bacterial respiratory infections, number of hospitalizations, and length of hospital stay in the 2 years prior to and after P-V inoculation. Among them [chronic obstructive pulmonary disease (COPD): 45; bronchial asthma: 24; bronchiectasis: 20 (including diffuse panbronchiolitis); and other diseases: 16], 98 patients were evaluated, except for seven patients who died of diseases other than respiratory infections within the 2 years after P-V inoculation. Subjects were 51 to 91 years of age (median: 74 yrs), the male-female ratio was 63:42, and 32 patients were on home oxygen therapy.

RESULTS

After P-V inoculation, decreases in the number of respiratory infections (3.16 vs. 1.95 infections; p=0.0004) and in the number of hospitalizations (0.79 vs. 0.43 hospitalizations; p=0.001) were observed. Furthermore, an analysis including other factors, i.e., number of patients on home oxygen therapy and influenza season, also revealed a decreased number of hospitalizations.

CONCLUSIONS

The additive inoculation of I-V and P-V in Japanese patients with chronic respiratory disease prevented the development of bacterial respiratory infections and warrants further study in patients with respiratory disease.

Usefulness of the QuantiFERON TB-2G test for the differential diagnosis of pulmonary tuberculosis

OBJECTIVE

We prospectively evaluated the usefulness of the QuantiFERON TB-2G (QFT-2G) compared to that of tuberculin skin test (TST) as a supportive method of diagnosing pulmonary tuberculosis (TB) without invasive examinations.

METHODS

The subjects were 90 patients who required differentiation of pulmonary TB clinically and for whom a definitive diagnosis could not be obtained after admission. The final clinical diagnosis of TB infection in 28 patients and non-TB infection in 62 patients was established using bronchoscopic procedures.

RESULTS

In patients with TB infection, the positive response rate on QFT-2G (79%) was significantly higher than that on TST (57%). The QFT-2G negative rate (5%) was significantly lower than that on TST (48%) in patients with non-TB infection. For QFT-2G test, there was a positive response in 25 patients, a negative response in 49, and indeterminate findings in 16. Of the two patients with a false-negative result on QFT-2G, one had pulmonary TB during immunosuppressive treatment and one had pulmonary tuberculoma. Of the three non-TB patients with a positive result on QFT-2G, two had pneumonia and one had pulmonary mycosis. Four TB patients with an indeterminate result on QFT-2G included two elderly patients and two immunocompromised patients.

CONCLUSIONS

We could confirm the usefulness of the QFT-2G test compared to TST in patients requiring a differential diagnosis between pulmonary TB and other pulmonary diseases in this series. Therefore, we recommend the QFT-2G test as one of the useful noninvasive diagnostic examinations for pulmonary TB.