Bacillus Calmette-Guérin Vaccination History Research Articles

Prevalence and risk factors of tuberculosis among people living with HIV/AIDS in China: a systematic review and meta-analysis

ObjectiveTo estimate the prevalence and risk factors associated with tuberculosis (TB) among people living with human immunodeficiency virus (HIV) infection/acquired immunodeficiency syndrome (AIDS) in China.MethodsA systematic review and meta-analysis were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. After the literature was screened based on the inclusion and exclusion criteria, STATA® version 17.0 software was used for the meta-analysis. The heterogeneity among study data was assessed using I2 statistics. Subgroup analysis and meta-regressions were performed to further explore the source of heterogeneity.ResultsA total of 5241 studies were retrieved. Of these, 44 studies were found to be eligible. The pooled prevalence of HIV/TB co-infection was 6.0%. The risk factors for HIV/TB co-infection included a low CD4+ T cell count, smoking, intravenous drug use and several other sociodemographic and clinical factors. Bacillus Calmette–Guérin (BCG) vaccination history was a protective factor.ConclusionA high prevalence of TB was observed among people living with HIV/AIDS in China. Low CD4+ T cell count, smoking, and intravenous drug use were the primary risk factors for HIV/TB co-infection, whereas BCG vaccination history was a protective factor. Checking for TB should be prioritized in HIV screening and healthcare access.Systematic review registrationRegistered on PROSPERO, Identifier: CRD42022297754.

Determining the Need for Additional Testing With Quantiferon TB Gold in Patients With Positive Tuberculin Skin Tests and a History of BCG Vaccination.

To determine if the QuantiFERON-TB Gold (QFT) testing can be obviated for the diagnosis of latent tuberculosis infection (LTBI) in patients with a positive tuberculin skin test (TST) and a history of Bacillus Calmette-Guerin (BCG)vaccination by identifying high-risk features in patients with positive TST and a history of BCG vaccination who are associated with positive QFT. Retrospective chart review was done for 76 adult patients by dividing them into two groups. Group 1 consisted of true positive TST patients who had BCG vaccination and were positive for QFT. Group 2 consisted of false positive TST patients who had BCG vaccination but were negative for QFT. The two groups were compared to determine if the high-risk features of TST induration diameter of 15mm and more, TST induration of 20mm and more, recent immigration to the US, the advanced age of more than 65 years, country of origin with high TB burden, known exposure to active TB, and smoking history were more prevalent in Group 1 compared to Group 2. Group 1 had 23 patients and Group 2 had 53 patients. Group 1 had a higher prevalence of patients with PPD induration of more than 10mm than Group 2, which was statistically significant with a P value of 0.03. Other risk factors of advanced age, exposure to active TB and smoking did not show statistically significant differences between Groups 1 and 2. Conclusion:This study also confirms that if the TST induration is more than 10mm in patients with a history of BCG vaccination, the TST induration is likely because of LTBI and is less likely because of cross-reaction with BCG vaccination.

Clinical Course of Bacillus Calmette-Guerin Lymphadenitis.

Bacillus Calmette-Guerin (BCG) vaccination can cause lymphadenitis. The purpose of the current study was to describe patient characteristics and clinical courses of lymphadenitis associated with BCG vaccination. A total of 171 patients who visited a tertiary hospital with a diagnosis of BCG-associated lymphadenitis between January 2012 and June 2017 were included. The diagnostic criteria were a history of BCG vaccination on the symptomatic side, absence of tenderness and raised temperature over the swelling, absence of fever and constitutional symptoms, and isolated axillary (or supraclavicular/cervical) lymph node (LN) enlargement. Treatment strategies included observation, antibiotics, incision and drainage or needle aspiration (I&D/NA), and surgical excision. The median follow-up period was 40 days (range 1–1245 days). The median age at the first visit was 5.5 months (range 0.9–83.7 months). The most common location was the axilla (81.3%). The respective numbers of patients managed via observation, I&D/NA, antibiotics, and surgical excision were 99, 47, 5, and 20. LNs were significantly more enlarged in the I&D/NA group than in the antibiotics group and the observation group. The respective times taken for residual lesions to reduce to < 20% were approximately 3 months, 4 months, and 5 months in the antibiotics, observation, and I&D/NA groups. The surgery group had significantly fewer residual lesions than the observation group at the last visit, but there was no significant difference in current residual lesions between the groups. LNs were significantly larger in the I&D/NA group. The surgery group exhibited the least residual lesions at the last visit, but there was no significant difference in current status.

Effectiveness of Bacillus Calmette-Guérin vaccination against severe childhood tuberculosis in China: a case-based, multicenter retrospective study

BackgroundEvidence varies regarding the efficacy of Bacillus Calmette-Guérin (BCG) vaccine. Data on protection by BCG vaccination against severe tuberculosis (TB) among children in China remain unclear. MethodsWe conducted a case-based, multicenter retrospective study at three children's hospitals in China. Sociological factors affecting BCG vaccination and risk factors associated with disease types were analyzed using a multivariable model. ResultsA total 1701 children with active TB were enrolled. Children who were younger, female, residing in a rural area, living in the western regions, and with no BCG vaccination history were at higher risk of developing severe TB. Children with a BCG scar had significantly lower risk for severe TB (odds ratio [OR] 0.59, 95% confidence interval [CI] 0.51–0.67). Children with no BCG scar but who were vaccinated at birth still had lower risk of severe TB types, such as tuberculous meningitis (OR 0.88, 95% CI 0.80–0.97) and miliary TB (OR 0.77, 95% CI 0.69–0.87). ConclusionsNeonatal BCG vaccination could be an effective means to control TB. In the absence of a new, more effective TB vaccine, our results lend support to continued use of the BCG vaccine in China.

EFFECTIVENESS OF BCG VACCINATION AGAINST SARS-COV-2

Background: Bacillus Calmette-Guerin (BCG) vaccine is weakened Mycobacterium bovis based preparation that provides protective effects and immunotherapy against many ailments and may be tested against SARS-COV-2. Herein, we compare the prevalence of COVID-19 in countries with and without mandatory BCG vaccination program along with a study to examine its incidence in doctors working at quarantine facility with and without history of prior BCG vaccination. Methods: For cross-sectional examination, the data was collated from worldometer.info, BCG World Atlas and COVID-19 stats at National Command and Operation Centre (NCOC), Government of Pakistan accessed on Apr 30, 2021. For a real-time analysis, total of one hundred random male and female doctors working at a COVID-19 healthcare facility in Pakistan were voluntarily selected. Chi-square test was used to perform the statistical analysis with the help of SPSS-22. Results: The prevalence of COVID-19 in countries with and without a mandatory BCG vaccination policy was found to be 5,512 and 75,592 cases per million, respectively, and mortality rates were 98 and 1,435 per million, respectively. Amongst our randomly selected doctors, only 28% of the BCG vaccinated doctors were affected by COVID-19 contrary to 94% of those who were unvaccinated. Conclusions: The incidence of COVID-19 was considerably lower in the doctors with a history of BCG vaccination supported by the evidence that the countries with a universal BCG vaccine policy had a significantly low incidence and lower mortality rate due to COVID-19.

BCG vaccination history associates with decreased SARS-CoV-2 seroprevalence across a diverse cohort of health care workers.

BACKGROUNDSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused more than 1 million deaths worldwide; thus, there is an urgent need to develop preventive and therapeutic strategies. The antituberculosis vaccine bacillus Calmette-Guérin (BCG) demonstrates nonspecific, protective innate immune-boosting effects. Here, we determined whether a history of BCG vaccination was associated with decreased SARS-CoV-2 infection and seroconversion in a longitudinal, retrospective observational study of a diverse cohort of health care workers (HCWs).METHODSWe assessed SARS-CoV-2 seroprevalence and collected medical questionnaires, which included information on BCG vaccination status and preexisting demographic and clinical characteristics, from an observational cohort of HCWs in a multisite Los Angeles health care organization. We used multivariate analysis to determine whether a history of BCG vaccination was associated with decreased rates of SARS-CoV-2 infection and seroconversion.RESULTSOf the 6201 HCWs, 29.6% reported a history of BCG vaccination, whereas 68.9% had not received BCG vaccination. Seroprevalence of anti-SARS-CoV-2 IgG as well as the incidence of self-reported clinical symptoms associated with coronavirus disease 2019 (COVID-19) were markedly decreased among HCWs with a history of BCG vaccination compared with those without BCG vaccination. After adjusting for age and sex, we found that a history of BCG vaccination, but not meningococcal, pneumococcal, or influenza vaccination, was associated with decreased SARS-CoV-2 IgG seroconversion.CONCLUSIONSA history of BCG vaccination was associated with a decrease in the seroprevalence of anti-SARS-CoV-2 IgG and a lower number of participants who self-reported experiencing COVID-19-related clinical symptoms in this cohort of HCWs. Therefore, large randomized, prospective clinical trials of BCG vaccination are urgently needed to confirm whether BCG vaccination can confer a protective effect against SARS-CoV-2 infection.

Severity of COVID-19 in bacillus Calmette-Guérin vaccinated population.

PurposeConsidering the cross-protection reported for bacillus Calmette-Guérin (BCG) vaccination on viral respiratory infections, it has been proposed that it could reduce the severity of coronavirus disease 2019 (COVID-19). The objective of the current study is to investigate the association between the severity of COVID-19 with prior BCG vaccination in adult patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.Materials and MethodsAdult patients (18 years or above) with positive SARS-CoV-2 polymerase chain reaction admitted in July 2020 were included in this cross-sectional study. Patients were classified into non-severe, severe, and critical diseases. History of prior BCG vaccination and the presence of a BCG vaccination scar were recorded.ResultsOut of 103 patients, 64 patients with prior history of BCG vaccinations were compared with 39 patients without BCG vaccination in childhood. The median age was 55 years and 64 years in BCG vaccinated & non-BCG vaccinated patients (p-value=0.002). There was male predominance in both groups and frequent comorbid illnesses were hypertension and diabetes mellitus. Severe COVID-19 was found in 91 patients (88.3%) followed by non-severe disease and critical diseases i.e., 7 (6.8%) and 5 (4.9%) patients, respectively. No association of prior BCG vaccination with disease severity of COVID-19 was found in this study and mortality was 8.7%. Out of nine patients who expired only 2 (22.2%) had a prior history of BCG vaccination (p-value=0.01). Secondary infections were present in 26 patients and the majority had pneumonia.ConclusionThe BCG vaccine has no impact on the severity of COVID-19 but could have a protective role with a low mortality rate in already infected patients.

Bacillus Calmette-Guérin (BCG) Infections at High Frequency in Both AR-CGD and X-CGD Patients Following BCG Vaccination.

Patients with chronic granulomatous disease (CGD) develop severe infections, including Bacillus Calmette-Guérin (BCG). Although the autosomal recessive CGD (AR-CGD) patients should hypothetically develop relatively fewer infections compared to the X-linked CGD (X-CGD) patients due to more residual reactive oxygen intermediates, the impacts of BCG vaccination on AR-CGD and X-CGD patients are unclear. Herein, we demonstrated the clinical features of BCG infections, treatments, and genetic factors in CGD patients after BCG vaccination under the Japanese immunization program. We collected data retrospectively from 43 patients with CGD and assessed their history of initial infection, age at diagnosis of CGD, BCG vaccination history, clinical course, treatment for BCG infections, and genetic mutations associated with CGD. Fourteen CGD patients avoided BCG vaccination because of other preceding infections and family history. Of 29 patients with CGD who received BCG vaccination, 20 patients developed BCG infections. Although the age at onset of initial infection in X-CGD patients was significantly younger than that in AR-CGD patients (P < .01), the onset and frequency of BCG infections were similar in X-CGD and AR-CGD patients. In X-CGD patients, BCG infections equally developed in the patients carrying missense, insertion, deletion, nonsense, and splice mutations of CYBB. All CGD patients with BCG infections were successfully treated with anti-tuberculous drugs. Although X-CGD patients develop severe infections at a younger age than AR-CGD patients, our data suggested that BCG infections develop at high frequency in both AR-CGD and X-CGD patients, regardless of genotype and mutant forms.

Primary Immunodeficiency Diseases and Bacillus Calmette-Guérin (BCG)-Vaccine–Derived Complications: A Systematic Review

Bacillus Calmette-Guérin (BCG) vaccine is a live attenuated bacterial vaccine derived from Mycobacterium bovis, which is mostly administered to neonates in regions where tuberculosis is endemic. Adverse reactions after BCG vaccination are rare; however, immunocompromised individuals and in particular patients with primary immunodeficiencies (PIDs) are prone to develop vaccine-derived complications. To systematically review demographic, clinical, immunologic, and genetic data of PIDs that present with BCG vaccine complications. Moreover, we performed a meta-analysis aiming to determine the BCG-vaccine complications rate for patients with PID. We conducted electronic searches on Embase, Web of Science, PubMed, and Scopus (1966 to September 2018) introducing terms related to PIDs, BCG vaccination, and BCG vaccine complications. Studies with human subjects with confirmed PID, BCG vaccination history, and vaccine-associated complications (VACs) were included. A total of 46 PIDs associated with BCG-VAC were identified. Severe combined immunodeficiency was the most common (466 cases) and also showed the highest BCG-related mortality. Most BCG infection cases in patients with PID were reported from Iran (n= 219 [18.8%]). The overall frequency of BCG-VAC in the included 1691 PID cases was 41.5% (95% CI, 29.9-53.2; I2= 98.3%), based on the results of the random-effect method used in this meta-analysis. Patients with Mendelian susceptibility to mycobacterial diseases had the highest frequency of BCG-VACs with a pooled frequency of 90.6% (95% CI, 79.7-1.0; I2= 81.1%). Several PID entities are susceptible to BCG-VACs. Systemic neonatal PID screening programs may help to prevent a substantial amount of BCG vaccination complications.

Comparison of QuantiFERON-TB Gold In-Tube (QFT-GIT) and tuberculin skin test (TST) for diagnosis of latent tuberculosis in haemodialysis (HD) patients: a meta-analysis of κ estimates.

Diagnosis of latent tuberculosis infection (LTBI) is a concern in haemodialysis (HD) patients. Many studies have compared QuantiFERON-TB Gold In-Tube (QFT-GIT) and tuberculin skin test (TST) for detecting LTBI and reported the κ statistic of agreement between QFT-GIT and TST in HD patients. The present study aimed to systematically review this literature and conduct meta-analysis of individual studies that estimated the κ between QFT-GIT with TST among HD patients. All relevant published studies that were available as full-text were obtained by searching Medline (1950), Web of Sciences (1945), Scopus (1973) through May 2016. The κ was re-estimated from the individual studies and pooled using random effect meta-analysis. Subgroup analysis and meta-regression were applied to evaluate the effect of Bacillus Calmette-Guérin (BCG) vaccination, TST cut-off points, quality of studies, sample size and age on variation of κ estimate. Eight studies involving 901 HD patients were included in meta-analysis. The pooled κ estimate was 0·28 (I 2 = 18·4%, P = 0·239, 95% confidence intervals 0·22-0·34). The discordance of TST-/QFT-GIT+ was more than TST+/QFT-GIT-. History of BCG vaccination, TST cut-off points and age are related to variation of κ estimates. TST and QFT-GIT are not comparable in detecting LTBI in HD patients. The higher TST-/QFT-GIT+ ratio compared with TST+/QFT-GIT- ratio, may indicate the superiority of QFT-GIT over TST for detection LTBI in HD patients.

Post-Vaccination Disseminated Bacillus Calmette Guerin Infection Among Children in Southern Iran.

Background:Disseminated bacillus calmette guerin (BCG) infection is a rare but life threatening complication of BCG vaccination. It has been mainly seen in severe immune deficiency. A precise and rapid diagnosis is crucial for prompt initiation of an aggressive anti-mycobacterial treatment. Polymerase chain reaction (PCR) is directly applicable to smear-positive clinical specimens, proven to be a rapid and specific diagnostic test.Objectives:The aim of this study was to investigate disseminated BCG infection among 34 children in southern Iran, mainly confirmed by PCR.Patients and Methods:We included all the patients hospitalized with disseminated BCG infection at a referral teaching hospital in southern Iran between years 1990 and 2007. The clinical and laboratory data including the immunological workups were obtained through a review of the medical files. We recalled all pathology samples from pathology specimen banks and used an in-house PCR specific for Mycobacterium bovis BCG substrain to confirm the diagnosis.Results:From the total of 34 children hospitalized with disseminated BCG infection, 21 were categorized as definite and 13 probable. Thirty-one patients (91%) were under two years of age and 41% were male. The most common clinical findings were fever in 31 (91.2%), axillary’s lymphadenopathy in 26 (76.5%), hepatosplenomegaly in 25 (73.5%), stunted growth in 21 (61.8%), and distant lymphadenopathy in 16 (47.1%). Polymerase Chain Reaction positivity rate was 100% (9 of 9) in bone marrow smear slides and 84.2% (16 of 19) for formalin-fixed and paraffin-embedded tissue specimens. Immunodeficiency state was detected in 50% and the overall mortality rate was 58.8% (20 of 34).Conclusions:Disseminated BCG infection should be considered in the differential diagnosis of infants and young children with fever, hepatosplenomegaly, lymphadenopathy, and history of BCG vaccination. The PCR method has a high positivity rate and can serve as a useful tool for the rapid and specific identification of M. bovis BCG substrain infection.

Individual-level factors associated with variation in mycobacterial-specific immune response: Gender and previous BCG vaccination status

A more effective tuberculosis (TB) vaccine is needed to eliminate TB disease. Many new vaccine candidates enhance the immunogenicity of the existing vaccine, Bacillus Calmette-Guérin (BCG). Understanding BCG induced immune variation is key to developing a new vaccine. We aimed to establish if individual-level covariates were associated with cell-mediated immune response (interferon gamma (IFN-γ)) at vaccine trial enrolment (baseline) in a long-term retrospective analysis (LTR) and after BCG vaccination in a short-term prospective analysis (STP). Four covariates were analysed: gender, country, BCG vaccination history and monocyte/lymphocyte cell count ratio. Univariable and multivariable linear regression were conducted on IFN-γ response at baseline for LTR, and area under the curve (AUC), 24 week and peak IFN-γ response for STP. Previous BCG vaccination was strongly associated with higher IFN-γ response at baseline (LTR analysis) (p-values < 0.05). Being male showed a weak association with higher baseline response (p-value = 0.1). BCG revaccination was strongly associated with a larger response increase than primary-vaccination (AUC & peak p-values < 0.01), but did not differ at 24 weeks (STP analysis). All other covariates were non-significant (p-values > 0.1). This analysis suggests that previous BCG vaccination and gender are associated with durable IFN-γ responses. Vaccine trials may need to stratify by BCG vaccination history and gender.

Attitudes towards latent tuberculosis among physicians in training: the role of BCG vaccination.

Prior work has demonstrated that international medical graduates physicians are less likely to recommend treatment of latent tuberculosis infection (LTBI) for themselves or their patients. Our objective was to measure differences in LTBI treatment attitudes among resident physicians when diagnosis is established with a positive tuberculin skin test (TST), as compared with a positive interferon gamma release assay (IGRA), and to determine whether a resident physician's personal history of Bacillus Calmette-Guerin (BCG) vaccination was associated with these attitudes. We conducted a cross-sectional survey of Internal Medicine resident physicians at two different training sites. Based on the country and year of birth, each respondent was assigned a putative BCG vaccination status based on a query of the BCG World Atlas (bcgworldatlas.org). We then asked whether the respondent agreed or disagreed with offering LTBI treatment in several clinical scenarios. Among their patients with a history of BCG vaccination, we found that resident physicians were least likely to agree with LTBI treatment for a first-ever positive TST, and most likely to agree with treatment for a converted IGRA. Contrary to our hypothesis, a resident physician's personal history of BCG vaccination was not associated with their LTBI treatment attitudes. Resident physicians broadly disagreed with LTBI treatment guidelines from the Centers for Disease Control and Prevention. Educational interventions designed to improve adherence to LTBI treatment recommendations should be broadly implemented, without regard to the educational or cultural backgrounds of physician.

Bacillus Calmette-Gu�rin (BCG) Vaccine-Induced Disease in Healthy Infants: Identification of BCG Gene from Formalin-Fixed Paraffin-Embedded Tissue

Background: Bacillus Calmette-Guérin (BCG) vaccineinduced systemic complication is rare but localized skin lesion develops in the site of inoculation in healthy infants. Methods: In this report, we described three cases of BCG vaccineinduced skin lesions in healthy immunocompetent infants and a method of identification of BCG gene by polymerase chain reaction (PCR) form fresh frozen of formalin-fixed and paraffinembedded tissue samples. Results: These cases had a history of BCG vaccination but no family history of tuberculosis and no contact with patients of tuberculosis. Two cases developed cutaneous granuloma in the axilla of ipsilateral side of BCG inoculation. Another case showed granulomatous osteomyelitis of the left 6th rib. Histological examination demonstrated typical pathologic findings for epithelioid granuloma with caseation necrosis, indicating mycobacterium infection. PCR analysis from fresh frozen or formalin-fixed paraffin-embedded tissue rapidly confirmed the infection of Mycobacterium bovis BCG but not M. tuberculosis. Conclusion: BCG infection should be considered even in healthy infants with a history of BCG vaccination and histology of epithelioid granuloma with caseation necrosis. In such cases, BCG gene identification by PCR would be useful even from formalin-fixed and paraffin embedded tissue samples.

Comparison of the QuantiFERON‐TB Gold In‐Tube test with the tuberculin skin test for detecting latent tuberculosis infection prior to hematopoietic stem cell transplantation

A total of 244 patients including 100 (41%) autologous hematopoietic stem cell transplant (HCT) recipients and 144 (59%) allogeneic HCT recipients were enrolled over a 28-month period. During the study period, no prophylaxis for latent tuberculosis (TB) infection was administrated. Of these, 201 (82%) had Bacillus Calmette-Guérin (BCG) scars or prior histories of BCG vaccination. The tuberculin skin test (TST) and the QuantiFERON-TB Gold In-Tube (QFT-GIT) test were performed simultaneously in all 244 patients. TST indurations were ≥ 5 mm in 39 of these patients (15%), and in 25 (10%) indurations were ≥ 10 mm. In addition, 40 (16%) had positive QFT-GIT outcomes, and 34 (14%) indeterminate outcomes. If the 34 patients with indeterminate QFT-GIT results were excluded from the overall agreement analysis, the agreement between the TST results (induration size ≥ 5 mm) and the QFT-GIT results in the 210 patients with clear QFT results was poor (κ = 0.08, 95% confidence interval [CI] -0.06 to 0.24), as it was for the patients with indurations ≥ 10 mm (κ = 0.15, 95% CI -0.004 to 0.31). During follow up, 2 patients developed TB after HCT. The incidence of TB in the patients with positive QFT-GIT outcomes was 2.80 per 100 person-years (95% CI 0.07-15.81), whereas among those with positive TST (≥ 5 mm) results, it was 0 per 100 person-years (95% CI 0-8.00). However, this finding should be cautiously interpreted because of the relatively short follow up and the fact that the sample size of the study cohort did not have adequate power. In conclusion, our data show that, although the frequencies of positive outcomes in the 2 TB screening tests were similar, the overall agreement between the TST and the QFT-GIT test was poor, regardless of BCG vaccination history.

Tuberculin skin test in bacille Calmette–Guérin-vaccinated children: how should we interpret the results?

The tuberculin skin test (TST) is the most useful method for the diagnosis of tuberculosis (TB). There is no evidence about the effect of bacillus Calmette-Guerin (BCG) vaccine on the interpretation of TST results. The aim of this study was to evaluate TST results in a population of immigrants and adopted children, analyzing the effect of the vaccine on TST. Cross-sectional observational study including immigrants or adopted children evaluated in our unit between January 2003 and December 2008 was made. Children diagnosed with TB, live attenuated virus vaccinated 2 months earlier, HIV-infected, chronically ill, or under treatment with immunosuppressive agents were excluded. TST was considered the dependent variable. Independent variables were gender, age, geographical origin, BCG scar, nutritional status, immune status, and intestinal parasites infestation. One thousand seventy-four children were included, 69.6 % are female; their origin includes China (34.7 %), Latin America (20.8 %), India/Nepal (19.4 %), Eastern Europe (15.7 %), and Africa (9.3 %). BCG scar was present in 79 % of children. Mantoux = 0 mm in 84.4 %, <10 mm in 4.1 %, and ≥10 mm in 11.4 %. Only two variables, age and BCG scar, influenced TST result. Risk of a TST false-positive due to BCG disappears 3 years after vaccine administration. A history of BCG vaccination at birth does not interfere with TST results in children >3 years old. Under 3 years of age, BCG does interfere with and may cause a false-positive TST result. In these cases, the use of interferon-gamma release assays (IGRAs) is recommended. If IGRAs are not available or when results are indeterminate, ignoring the antecedent of the vaccine is recommended.

High-sensitive and rapid detection of Mycobacterium tuberculosis infection by IFN-γ release assay among HIV-infected individuals in BCG-vaccinated area

BackgroundAn accurate test for Mycobacterium tuberculosis infection is urgently needed in immunosuppressed populations. The aim of this study was to investigate the diagnostic power of enzyme-linked immunospot (ELISPOT)-based IFN-γ release assay in detecting active and latent tuberculosis in HIV-infected population in bacillus Calmette-Guerin (BCG)-vaccinated area. A total of 100 HIV-infected individuals including 32 active tuberculosis patients were recruited. An ELISPOT-based IFN-γ release assay, T-SPOT.TB, was used to evaluate the M. tuberculosis ESAT-6 and CFP-10 specific IFN-γ response. Tuberculin skin test (TST) was performed for all recruited subjects.ResultsThe subjects were divided into group HIV+ATB (HIV-infected individuals with active tuberculosis, n = 32), group HIV+LTB (HIV-infected individuals with positive results of T-SPOT.TB assay, n = 46) and group HIV only (HIV-infected individuals with negative results of T-SPOT.TB assay and without evidence of tuberculosis infection, n = 22). In group HIV+ATB and HIV+LTB, T-SPOT.TB positive rate in subjects with TST <5 mm were 50% (16/32) and 41.3% (19/46), respectively. Individuals in group HIV+ATB and HIV+LTB with CD4+ T cells <500/μl, T-SPOT.TB showed a higher sensitivity than TST (64.5% vs. 22.6% and 62.2% vs. 29.7%, respectively, both P < 0.0001). In addition, the sensitivity of T-SPOT.TB assay in group HIV+ATB increased to >85% in patients with TB treatment for less than 1 month and CD4+ T cells ≥200/μl, while for patients treated for more than 3 months and CD4+ T cells <200/μl, the sensitivity was decreased to only 33.3%. Furthermore, the results could be generated by T-SPOT.TB assay within 24 hours, which was more rapid than TST with 48–72 hours.ConclusionELISPOT-based IFN-γ release assay is more sensitive and rapid for the diagnosis of TB infection in Chinese HIV-infected individuals with history of BCG vaccination, and could be an effective tool for guiding preventive treatment with isoniazid in latently infected people and for TB control in China.

Protective effect of Bacillus Calmette-Guerin (BCG) vaccination in children with extra-pulmonary tuberculosis, but not the pulmonary disease: A case-control study in Rosario, Argentina

A hospital-based case-control study was carried out at the Vilela Children's Hospital in Rosario, Argentina, to measure the protection conferred by BCG vaccination against tuberculosis (TB). The study included 148 newly diagnosed cases of TB (75 males and 73 females, mean age 3.34 ± 2.97 years, S.D.), 134 of them with pulmonary TB and 14 cases with extra-pulmonary disease. Controls (425 males and 357 females, 3.39 ± 2.98 years) were selected randomly among children who attended to the Hospital showing, neither respiratory diseases nor any other infectious illnesses. Information on BCG vaccination history was assessed from scars or immunisation records. All participants were negative to human immunodeficiency virus and belonged to the lower and upper-lower socioeconomic status, being similar in place of residence and ethnic characteristics. Rate of vaccinated children was 92.6% of cases and 94.5% of controls (3.4 and 3.9% of them without scars, respectively). Regarding the total cases, the protective association between BCG and TB was statistically insignificant, as was for the pulmonary form. Among cases with extra-pulmonary disease, vaccine effectiveness attained significance [79% (95% CI = 26–94)], no matter their age, sex or nutritional status. BCG vaccination exerted a beneficial role in extra-pulmonary TB, even in children not seriously undernourished.

Prevalence of tuberculin reactivity among healthcare workers from a Mexican hospital.

The prevalence of tuberculosis (TB) infection in healthcare workers (HCWs) is completely unknown in Mexico. To evaluate the frequency of TB infection in our hospital, we performed a prevalence study of tuberculin reactivity among a random sample of asymptomatic HCWs. Our results showed an extremely high prevalence of PPD reactivity (70%) among 175 HCWs, probably related to the high incidence of active TB in the general population and to the absence of preventive programs.