Serious adverse events associated with bacille Calmette-Guérin vaccine in Canada

BCG Vaccination Reprograms the Function of M-MDSCs and Aggravates Necrotizing Enterocolitis in Neonates

Bacillus Calmette-Guérin (BCG), a live-attenuated vaccine primarily used against tuberculosis (TB), also provides protection against a broad array of antigens or heterologous antigens through the induction of trained immunity (TI). While BCG is generally safe for full-term infants, its application in preterm infants is contentious due to their immature immune systems and heightened susceptibility to adverse effects. Preterm infants, particularly those with low birth weight, are at an elevated risk of severe complications, such as necrotizing enterocolitis (NEC), a life-threatening inflammatory condition of the intestines. NEC is characterised by dysregulated immune responses to microbial colonisation, with myeloid-derived suppressor cells (MDSCs) playing a crucial role in maintaining immune tolerance during early life. This study reveals that BCG vaccination significantly exacerbates NEC severity (p = 0.0048) by enhancing glycolysis and upregulating mTOR-HIF1α signalling in neonatal monocytic MDSCs (M-MDSCs), thereby impairing their immunosuppressive function. Pharmacological or genetic inhibition of mTOR-HIF1α signalling or glycolysis pathways restored M-MDSC function and mitigated NEC severity. These findings complement our previous work on BCG's effects on polymorphonuclear (PMN)-MDSCs and highlight the dual role of BCG: while it provides protective benefits in certain contexts, it may also increase NEC risk in preterm infants by disrupting MDSC-mediated immune tolerance. This study offers critical insights into the mechanisms underlying BCG's off-target effects and underscores the necessity of tailored vaccination strategies for preterm infants to minimise potential risks.

Analysis of Health-Related Quality of Life and Incurred Costs Among Human Immunodeficiency Virus, Tuberculosis, and Tuberculosis/HIV Coinfected Outpatients in Indonesia

OBJECTIVES

A growing interest in healthcare costs and patients' health-related quality of life (HRQoL) exists in the context of the increasing importance of health technology assessment in countries with high numbers of the HIV and tuberculosis (TB) patient populations, such as Indonesia. This study aimed to analyze the HRQoL and out-of-pocket (OOP) costs of HIV, TB, and TB/HIV coinfected participants in a city in Indonesia with a high prevalence of HIV and TB.

METHODS

A cross-sectional survey was conducted in the voluntary counseling and testing and lung clinics of Bekasi City Public Hospital (Indonesia) from January to March 2018. Patients' HRQoL was measured using the EQ-5D-5L questionnaire, whereas OOP costs were extracted from a semistructured questionnaire.

RESULTS

Of the 460 eligible participants, 82% resided in the city, 48% of them were married, and their median age was 34 years. Less than half were insured, and more than half had no source of income. The median values of health utilities for participants with HIV, TB, and TB/HIV were perceived as potentially high (1.0, 0.9, and 0.8, respectively). The TB/HIV coinfected outpatients had the highest OOP costs (US$94.5), with the largest contribution coming from direct medical OOP expenditures. Taking loans from family members was adopted as a financial strategy to overcome inadequate household incomes and high treatment costs.

CONCLUSION

This study suggests that TB/HIV coinfection potentially lowers HRQoL and increases healthcare costs and the need for economic analysis to underpin cost-effective treatment in such patients.

Information systems for vaccine safety surveillance

Immunization implementation in the community relies upon post-licensure vaccine safety surveillance to maintain safe vaccination programs and to detect rare AEFI not observed in clinical trials. The increasing availability of electronic health-care related data and correspondence from both health-related providers and internet-based media has revolutionized health-care information. Many and varied forms of health information related to adverse event following immunization (AEFI) are potentially suitable for vaccine safety surveillance. The utilization of these media ranges from more efficient use of electronic spontaneous reporting, automated solicited surveillance methods, screening various electronic health record types, and the utilization of natural language processing techniques to scan enormous amounts of internet-based data for AEFI mentions. Each of these surveillance types have advantages and disadvantages and are often complementary to each other. Most are "hypothesis generating," detecting potential safety signals, where some, such as vaccine safety datalinking, may also serve as "hypothesis testing" to help verify and investigate those potential signals.

First vaccination after birth: serious adverse events of Bacillus Calmette-Guérin (BCG) in real-world

The Bacillus Calmette-Guérin (BCG) vaccine is a free vaccine in China, and more than 300 million newborns have been vaccinated. Inevitably, the BCG vaccine will have some rare adverse events on the first day of life (24 hours after birth), but related reports are extremely rare. In this commentary, the authors searched the Chinese legal documents database for documents related to serious adverse events caused by BCG from January 2010 to January 2022. Fourteen pediatric cases were identified, including 7 preterm infants and 7 full-term infants. The events included 4 cases of interstitial pneumonia, 3 cases of lymphadenitis, 3 cases of septicemia, 1 case of myocarditis, 1 case of muscle atrophy, 1 case of epilepsy, and 1 case of disseminated BCG vaccine. The mortality rate of preterm infants was 100% and that of full-term infants was 28.6% (2/7). All deaths occurred within one day. The BCG vaccine has good safety for the vast majority of newborns.

To our knowledge, we present the largest case series of BCG vaccine-induced serious adverse events in neonates.

The BCG vaccine has good safety for the vast majority of newborns.

The incidence of serious adverse events with BCG vaccine may be as low as eight per million.

Physician vaccination practices in mild to moderate inborn errors of immunity and retrospective review of vaccine completeness in IEI: results from the Canadian Immunization Research Network

Background and objectives

Safety and effectiveness concerns may preclude physicians from recommending vaccination in mild/moderate inborn errors of immunity (IEI). This study describes attitudes and practices regarding vaccination among physicians who care for patients with mild/moderate B cell or mild/moderate combined immunodeficiencies (CID) and vaccination completeness among patients diagnosed with IEIs.

Methods

Canadian physicians caring for children with IEI were surveyed about attitudes and practices regarding vaccination in mild/moderate IEI. Following informed consent, immunization records of pediatric patients with IEI evaluated before 7 years of age were reviewed. Vaccine completeness was defined at age 2 years as 4 doses of diphtheria-tetanus-pertussis (DTaP), 3 doses pneumococcal conjugate (PCV), and 1 dose measles-mumps-rubella (MMR) vaccines. At 7 years 5 doses of DTP and 2 doses MMR were required.

Results

Forty-five physicians from 8 provinces completed the survey. Most recommended inactivated vaccines for B cell deficiency: (84% (38/45) and CID (73% (33/45). Fewer recommended live attenuated vaccines (B cell: 53% (24/45), CID 31% (14/45)). Of 96 patients with IEI recruited across 7 centers, vaccination completeness at age 2 was 25/43 (58%) for predominantly antibody, 3/13 (23%) for CID, 7/35 (20%) for CID with syndromic features, and 4/4 (100%) for innate/phagocyte defects. Completeness at age 7 was 15%, 17%, 5%, and 33%, respectively.

Conclusion

Most physicians surveyed recommended inactivated vaccines in children with mild to moderate IEI. Vaccine completeness for all IEI was low, particularly at age 7. Further studies should address the reasons for low vaccine uptake among children with IEI and whether those with mild-moderate IEI, where vaccination is recommended, eventually receive all indicated vaccines.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13223-022-00667-1.

The Spectrum of Bacille Calmette-Guérin Diseases in Children-A Decade of Data from Neonatal Vaccination Settings

In this paper, we present a multicentre record-based descriptive study used to estimate the incidence and characterize the spectrum of confirmed bacille Calmette–Guérin (BCG) vaccine-related disease among children in Oman. This study included all children (age ≤ 14 years) who had culture and/or polymerase chain reaction (PCR)-confirmed BCG disease from January 2006 to December 2018, as identified from Central Public Health Laboratory data and International Classification of Diseases coding of an electronic patient information system. In total, 88 children confirmed to have BCG disease were included in the study, making an average incidence of 9.2 cases per 100,000 vaccinated neonates. The males comprised 65.9%, Omanis 93.2%, and the median age of presentation was 4 months in children with BCG disease. The most common type of disease was BCG abscesses (72.4%). Children with immunodeficiency and those presenting within 6 months were found to have a more severe and disseminated disease. In total, 28 children had immunodeficiency. The age of presentation and type of BCG disease was significantly associated with immunodeficiency status. The majority of cases required therapy (both medical and surgical) and recovered well. The incidence of laboratory-confirmed BCG vaccine-related disease was low in Oman supporting continuing the use of the BCG vaccination practice at birth.

Active surveillance of acute paediatric hospitalisations demonstrates the impact of vaccination programmes and informs vaccine policy in Canada and Australia

Sentinel surveillance of acute hospitalisations in response to infectious disease emergencies such as the 2009 influenza A(H1N1)pdm09 pandemic is well described, but recognition of its potential to supplement routine public health surveillance and provide scalability for emergency responses has been limited. We summarise the achievements of two national paediatric hospital surveillance networks relevant to vaccine programmes and emerging infectious diseases in Canada (Canadian Immunization Monitoring Program Active; IMPACT from 1991) and Australia (Paediatric Active Enhanced Disease Surveillance; PAEDS from 2007) and discuss opportunities and challenges in applying their model to other contexts. Both networks were established to enhance capacity to measure vaccine preventable disease burden, vaccine programme impact, and safety, with their scope occasionally being increased with emerging infectious diseases’ surveillance. Their active surveillance has increased data accuracy and utility for syndromic conditions (e.g. encephalitis), pathogen-specific diseases (e.g. pertussis, rotavirus, influenza), and adverse events following immunisation (e.g. febrile seizure), enabled correlation of biological specimens with clinical context and supported responses to emerging infections (e.g. pandemic influenza, parechovirus, COVID-19). The demonstrated long-term value of continuous, rather than incident-related, operation of these networks in strengthening routine surveillance, bridging research gaps, and providing scalable public health response, supports their applicability to other countries.

Increase in the diagnosis of mycobacteremia after the implementation of semi-automated blood culture at a Brazilian public health laboratory

INTRODUCTION

The prevalence of hematogenous dissemination of mycobacteria is high in immunosuppressed patients. The isolation of mycobacteria in culture remains the standard procedure.

METHODS

This is a cross-sectional study based on the results of solid (Löwenstein-Jensen medium) and semi-automated liquid (BACTEC 9240) blood cultures, obtained from the Lacen-GO database.

RESULTS

The implementation of a semi-automated procedure resulted in an increase of 61.5% and 350.0% in the positive results for Mycobacterium tuberculosis complex and nontuberculous mycobacteria, respectively. This technique also accelerated the detection of positive results.

CONCLUSIONS

Semi-automated liquid blood culture showed a better performance in the diagnosis of mycobacteremia.

Recommendations for pediatric tuberculosis vaccination in Italy

Bacillus Calmette-Guérin (BCG) vaccine is still the only vaccine approved for the prevention of tuberculosis (TB), and is widely used in highly endemic countries, where all newborns receive a single intradermal dose immediately after birth; however, the recommendations concerning its use in Europe vary widely from country to country. This document describes the recommendations of a group of Italian scientific societies concerning its pediatric use in Italy, the persistence of the protection it provides, its safety, its interference with tuberculin skin test (TST) responses, and the children who should be vaccinated. The experts conclude that BCG vaccination provides a good level of protection against tuberculous meningitis and disseminated forms, and a fair level of protection against pulmonary disease; the protective effective lasts at least 10 years, and revaccination offers no advantages over a single administration. The vaccine is safe in immunocompetent subjects, and affects the response to a TST for at least 6 y On the basis of these observations, we recommend its use in Italy in all TST-negative immunocompetent newborns and breastfeeding infants aged <6 months, and all TST-negative children aged between 6 months and 5 y who come from highly epidemic areas, or whose parents come from highly endemic areas, or who have been in contact with a family member with active TB without contracting the disease themselves.

CLINICAL MANAGEMENT OF LOCALIZED BCG ADVERSE EVENTS IN CHILDREN

BCG adverse events (BCG-AE) are rare conditions with no well-established treatment. This study aims to describe clinical characteristics and outcome of localized BCG-AE. Children with BCG-AEs who were treated at the Reference Center for Special Immunobiologicals of the Federal University of São Paulo from 2009 to 2011 were included. Patients were followed monthly until 3 months after healing. One hundred and twenty-seven patients with localized BCG-AE were followed: 67 (52.7%) had suppurative lymphadenitis; 30 (23.6%) injection-site abscess; five (3.9%) had enlarged lymph node > 3 cm; four (3.1%) had ulcer > 1 cm; and one (0.8%) had a local bacterial infection. Five patients (3.9%) had more than one BCG-AE simultaneously. Fifteen patients (11.8%) had atypical manifestations: seven wart-like lesions; five BCG reactivations; two other dermatologic lesions and one with vasomotor phenomenon. Isoniazid was used in 96 patients with typical BCG-AE (85.7%) until lesion resolution which took place 3.1 months later (in median); the healing rate was 90.6%. Patients with atypical manifestations had an individual approach. Regarding the outcome, 105/112 patients with typical AE and 13/15 patients with atypical AE had resolution of BCG-AE. Localized BCG-AE caused by BCG Moreau RJ had positive outcome when treated with a short course of isoniazid. Atypical BCG-AE are not infrequent.

Management and outcome of Bacille Calmette-Guérin vaccine adverse reactions

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BCG vaccine is the one of the most widely used vaccines globally.

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Local complications are commonly seen but approach to management varies.

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Injection site reactions and non-suppurative lymphadenitis can be managed conservatively.

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Aspiration may be beneficial in suppurative lymphadenitis.

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Antimicrobials and surgery are rarely required except for non-resolving cases.

Background

Bacille Calmette-Guérin (BCG) vaccine is one of the most widely used vaccines globally. Management of local BCG complications (injection site reactions and suppurative or non-suppurative lymphadenitis) varies between clinicians, and the optimal approach remains uncertain.

Aim

To determine the clinical features, management and outcome of BCG complications at two large acute hospitals in London, United Kingdom.

Methods

All children presenting with complications of BCG vaccination between January 2008 and December 2013 were included in this observational study. Medical and electronic laboratory records were reviewed to determine clinical features, treatment and outcome.

Results

Sixty children presented with adverse reactions. Two-thirds (65%) presented with BCG lymphadenitis, one-third (30%) presented with injection site complications and two children (3%) presented with both injection site reaction and lymphadenitis; only one child (2%) had disseminated BCG disease. The majority (88%) of children with injection site reactions were managed conservatively; overall, 95% showed complete resolution within 6 months. Among children with lymphadenitis, 46% were managed conservatively, whilst 54% had anti-tuberculous therapy and/or a procedure (aspiration mostly, or surgery); complete resolution was seen in 59% of cases.

Conclusions

Injection site reactions and non-suppurative lymphadenitis were generally managed conservatively, with good outcomes. There was more variation in management and outcome of suppurative lymphadenitis and the optimal approach remains uncertain.

Pharmacovigilance in children: detecting adverse drug reactions in routine electronic healthcare records. A systematic review

AIMS

A systematic review of the literature published in English over 10 years was undertaken in order to describe the use of electronic healthcare data in the identification of potential adverse drug reactions (ADRs) in children.

METHODS

MEDLINE and EMBASE were searched using MESH headings and text words. Titles, keywords and abstracts were checked for age <18 years, potential ADRs and electronic healthcare data. Information extracted included age, data source, pharmacovigilance method, medicines and ADRs. Studies were quality assessed.

RESULTS

From 14 804 titles, 314 had a full text review and 71 were included in the final review. Fifty were published in North America, 10 in Scandinavia. Study size ranged from less than 1000 children to more than 10 million. Sixty per cent of studies used data from one source. Comparative observational studies were most commonly reported (66.2%) with 15% using passive surveillance. Electronic healthcare data set linkage and the quality of the data source were poorly reported. ADRs were classified using the International Classification of Disease (ICD10). Multi-system reactions were most commonly studied, followed by central nervous system and mental and behavioural disorders. Vaccines were most frequently prescribed followed by corticosteroids, general anaesthetics and antidepressants.

CONCLUSIONS

Routine electronic healthcare records were increasingly reported to be used for pharmacovigilance in children. This growing and important health protection activity could be enhanced by consistent reporting of studies to improve the identification, interpretation and generalizability of the evidence base.

Clinical, laboratory and imaging findings of the patients with disseminated bacilli Calmette-Guerin disease

OBJECTIVES

In the present study, we reviewed 44 cases of disseminated BCG infection during a 10-year period in an Iranian referral children medical centre hospital.

MATERIAL AND METHODS

In this study, all of the patients with clinical and laboratory findings that were compatible with a diagnosis of disseminated BCG were included.

RESULTS

Through 10 years evaluation, 44 patients were found with disseminated BCG disease. Hepatomegaly and splenomegaly were seen in 68% and 66% of patients, respectively. Osteomyelitis was observed in 9% of our cases. Decrease in blood cells including anaemia, leucopoenia, neutropenia and thrombocytopenia were associated with more severe disease and even deaths. Moreover, 80% and 70% of patients who died had high level of C reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Among the dead patients, 80% had abnormal sonography. Thirty nine percent of patients had immunodeficiency, while more than half of the patients who died had no identified immunodeficiency.

CONCLUSION

These findings confirm the need to do sonography as well as bone imaging immediately in all patients with BCGitis. Assessment of the inflammatory factors in order to predict the prognosis of the disease is recommended. Furthermore, complete blood count would provide important information and should perform in all patients with BCGitis.

The Canadian Immunization Monitoring Program, ACTive (IMPACT): Active surveillance for vaccine adverse events and vaccine-preventable diseases

For almost 25 years the Canadian Immunization Monitoring Program, ACTive (IMPACT) has been conducting active surveillance for severe adverse events following immunization (AEFIs) and vaccine-preventable diseases in children. The network, which consists of volunteer paediatric infectious diseases investigators at 12 tertiary care paediatric hospitals, is an important component of Canada's AEFI monitoring. The network employs nurses at each of the sites to search for and report possible AEFIs to local, provincial and national public health authorities. The active nature of the surveillance ensures a high level of vigilance for severe AEFIs in children.

Incidence, spectrum and outcome of immune reconstitution syndrome in HIV-infected children after initiation of antiretroviral therapy

BACKGROUND

Immune reconstitution syndrome (IRS) is a relatively common complication in HIV-infected adults starting combination antiretroviral therapy (cART). Data on IRS in HIV-infected children remain limited and are largely restricted to resource-limited settings. This study investigated the incidence, spectrum and outcome of IRS in a pediatric cohort in the United Kingdom.

METHODS

Retrospective analysis of clinical events during the first 12 months after initiation of cART in 135 treatment-naïve, HIV-infected children in the United Kingdom over a 5-year period. Demographic and laboratory data were provided by the Collaborative HIV Paediatric Study.

RESULTS

The median age at cART initiation was 6.6 years (interquartile range: 2.3-10.2). The median CD4 lymphocyte percentage (CD4%) at baseline was 15% (median CD4 lymphocyte count: 390 cells/μL). Eight patients (5.9%) developed IRS (incidence: 5.7/100 person years). The IRS events comprised: Bacillus Calmette-Guerin-related complications (local ulceration/lymphadenitis; n = 4), pulmonary tuberculosis (n = 1), Mycobacterium avium intracellulare infection (n = 1), combined tuberculosis/Mycobacterium avium intracellulare infection (n = 1) and cutaneous herpes simplex (n = 1). The mortality was significantly higher in children with IRS than in those without (P < 0.0001). The only statistically significant risk factor for IRS identified was increment in CD4 count at 12 months after starting cART (P = 0.03).

CONCLUSIONS

The incidence of IRS was significantly lower than previously reported from resource-limited settings, likely reflecting less profound immunodeficiency at cART initiation and fewer coexisting opportunistic infections in our cohort. However, IRS events were associated with considerable morbidity and mortality. Therefore, preventive strategies that can reduce the risk of IRS in children need to be identified.

Severe combined immunodeficiency (SCID) in Canadian children: a national surveillance study

PURPOSE

Severe Combined Immune Deficiency (SCID) is universally fatal unless treated with hematopoietic stem cell transplantation (HSCT). Following the identification of disseminated Bacille Calmette-Guérin (BCG) infections in Canadian First Nations, Métis and Inuit (FNMI) children with unrecognized primary immune deficiencies, a national surveillance study was initiated in order to determine the incidence, diagnosis, treatment and outcome of children with SCID in Canada.

METHODS

Canadian pediatricians were asked to complete a monthly reporting form if they had seen a suspected SCID case, from 2004 to 2010, through the Canadian Paediatric Surveillance Program (CPSP). If the case met CPSP SCID criteria, more detailed data, including demographics and clinical information about investigations, treatment and outcome was collected.

RESULTS

A total of 40 cases of SCID were confirmed for an estimated incidence of SCID in non-FNMI Canadian children of 1.4 per 100,000 live births (95 % CI 1 to 1.9/100,000). The proportion of SCID cases that were FNMI (17.5 %) was almost three times higher than was expected on the basis of proportion of the pediatric population estimated to be FNMI (6.3 %) resulting in an estimated incidence of 4.4 per 100,000 live births (95 % CI 2.1 to 9.2/100,000) in FNMI Canadian children. The mean age at diagnosis for all SCID cases was 4.2 months (range 1–583 days). There were 12 deaths (30 %; 95 % CI 18–46 %); seven died of confirmed or suspected infections before they could receive an HSCT.

CONCLUSIONS

The frequency of SCID cases in FNMI children is higher than in the general Canadian pediatric population. The high mortality rate, due primarily to infection, suggests that early diagnosis by newborn screening followed by HSCT could significantly benefit children with SCID.

Evaluating clinical course of BCG lymphadenitis and factors affect on it during a 5-year period in Kerman, Iran

INTRODUCTION

One of the preventive methods of pulmonary tuberculosis is bacillus Calmette-Guérin (BCG) vaccination and one of the common complications of vaccine is lymphadenitis. We aimed to evaluate clinical course of BCG lymphadenitis in children of Kerman Province, Iran.

METHOD

314 children with BCG lymphadenitis were enrolled in study. Patients were followed up monthly regarding clinical improvement and complications.

RESULTS

BCG lymphadenitis was improved in many patients during follow up; during 6 months 23.7% of patients had spontaneous regression. Only the primary size of lymphadenitis had significant effect on clinical course of lymphadenitis and developing complication (p = 0.0540).

CONCLUSION

Many patients improved without any intervention. The primary size of lymphadenitis may affect clinical course of lymphadenitis and dispose person to abscess and fistula. To confirm this result and evaluate efficiency of preventive surgery instead of observation further study is recommended.

Control of chronic mycobacterium tuberculosis infection by CD4 KLRG1- IL-2-secreting central memory cells

The bacille Calmette-Guérin vaccine provides very efficient protection in standard animal models of Mycobacterium tuberculosis challenge. We show in this article that although bacille Calmette-Guérin controlled M. tuberculosis growth for 7 wk of infection, the protection was gradually lost as the infection entered the chronic phase. The regrowth of M. tuberculosis coincided with an almost complete disappearance of IL-2-producing CD4 T cells. Booster vaccination with a subunit vaccine (Ag85B-ESAT-6+CAF01) expanded IL-2(+) CD4(+) T cell coexpressing either TNF-α or TNF-α/IFN-γ, and the maintenance of this population in the late stage of infection was associated with enhanced control of bacterial growth. The IL-2(+) CD4(+) T cell subsets were KLRG1(-) (nonterminally differentiated), were found to be CD62L(high), and further maintained a pronounced proliferative and cytokine-producing potential in the draining lymph nodes, when the animals were challenged 2 y postvaccination. These results suggest that the CD4(+) KLRG1(-) IL-2-secreting subsets are central memory T cells with the potential to continuously replenish the T cells at the site of infection and prevent attrition and functional exhaustion.

Treating BCG-induced disease in children

BACKGROUND

Bacillus Calmette-Guerín (BCG) is a live attenuated vaccine to prevent tuberculosis, routinely administered at birth as part of the World Health Organization global expanded immunisation programme. Given intradermally, it can cause adverse reactions, including local, regional, distant and disseminated manifestations that may cause parental distress. Rarely, it can cause serious illness and even death. Among those patients with immunocompromised conditions, such as the human immunodeficiency virus (HIV) infection, the complication rate is even higher.

OBJECTIVES

To assess the effects of different interventions for treating BCG-induced disease in children.

SEARCH METHODS

The following databases were searched: the Cochrane Infectious Diseases Group Specialized Register and Cochrane Central Register of Controlled Trials (CENTRAL), published in The Cochrane Library (The Cochrane Library 2012, Issue 4); MEDLINE (1966 to November 2012); EMBASE (1947 to November 2012); and LILACS (1980 to November 2012). The metaRegister of Controlled Trials (mRCT) and the WHO trials search portal. Conference proceedings for relevant abstracts and experts were also contacted to identify studies. No language restrictions were applied.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing any medical or surgical treatment modality for BCG-induced disease in children.

DATA COLLECTION AND ANALYSIS

Two authors independently evaluated titles, applied inclusion criteria, and assessed the risk of bias of studies. The primary outcomes were the failure rate of therapies for all types of BCG vaccine-induced complications and the time to resolution of illness measured in months. The secondary outcomes were death from BCG vaccine-induced disease and the all-cause mortality. Risk ratios (RRs) were used as measure of effect for dichotomous outcomes and mean differences for continuous outcomes.

MAIN RESULTS

Five RCTs analysing 341 children addressed the primary outcomes and were included. Four arms compared oral antibiotics to no intervention or placebo, one arm evaluated needle aspiration compared to no intervention, and another evaluated the use of locally instilled isoniazid versus oral erythromycin.Two small studies evaluated oral isoniazid; we are uncertain of whether this intervention has an effect on clinical failure (RR 1.48; 95% Confidence Interval (CI) 0.79 to 2.78; 54 participants, two studies, very low quality evidence). Similarly, for oral erythromycin, we are uncertain if there is an effect (clinical failure RR 1.03; 95% CI 0.70 to 1.53; 148 participants, three studies, very low quality evidence), and for oral isoniazid plus rifampicin (clinical failure, RR 1.20; 95% CI 0.51 to 2.83; 35 participants, one study, very low quality evidence).In patients with lymphadenitis abscess, needle aspiration may reduce clinically persistent BCG-induced disease at 6 to 9 months of follow-up (RR 0.13; 95% CI 0.03 to 0.55; 77 participants, one study, low quality evidence). In another study of patients with the same condition, aspiration plus local instillation of isoniazid reduces time to clinical cure compared to aspiration plus oral erythromycin (mean difference 1.49 months less; 95% CI 0.82 to 2.15 less; 27 participants, one study).No RCTs of HIV-infected infants with a BCG-induced disease evaluated the use of antibiotics or other therapies for reducing the rate of clinical failure or the time to clinical resolution. No data on mortality secondary to the interventions for treating BCG-induced disease were reported.

AUTHORS' CONCLUSIONS

It is unclear if oral antibiotics (isoniazid, erythromycin, or a combination of isoniazid plus rifampicin) are effective for the resolution of BCG-induced disease. Most non-suppurated lymphadenitis will resolve without treatment in 4 to 6 months. Patients with lymphadenitis abscess might benefit from needle aspiration and possibly local instillation of isoniazid could shorten recovery time. Included studies were generally small and could be better conducted. Further research should evaluate the use of needle aspiration and local instillation of isoniazid in fluctuant nodes. Therapeutic and preventive measures in HIV-infected infants could be important given the higher risk of negative outcomes in this group.

Bacillus Calmette-Guérin-related cold thigh abscess as an unusual cause of thigh swelling in infants following BCG vaccine administration: a case series

INTRODUCTION

Thigh swelling in an infant can be a symptom of a simple benign condition or a life-threatening condition. We observed a cluster of thigh swelling episodes in infants in which the cause was Bacillus Calmette-Guérin-related cold thigh abscess. We report this unusual case series to raise awareness about this diagnosis.

CASE PRESENTATIONS

We performed a retrospective review of five infants (four boys and one girl) who presented with Bacillus Calmette-Guérin-related left thigh abscess. The swelling was noticed by the parents at a mean period of three months prior to presentation. The ages at presentation were five, five, eight and nine months for the boys, and six months for the girl. All of the patients were healthy Saudi infants, and received the Bacillus Calmette-Guérin vaccine at birth. Clinically, all of the patients were well and did not demonstrate signs of systemic infection. All patients underwent needle aspiration, with subsequent incision and drainage in four of the five cases. The cultures obtained from the abscess fluids were the key to establishing the diagnosis. Only three patients (60%) received antituberculosis drugs. Wound healing lasted for a mean period of approximately seven months. Two-year follow-up was unremarkable for all of our patients.

CONCLUSIONS

Technical errors continue to be significant in the development of vaccine-related complications. Bacillus Calmette-Guérin-related cold thigh abscess is an extremely rare entity.

Evaluation of Toxoplasma gondii as a live vaccine vector in susceptible and resistant hosts

Background

Toxoplasma gondii has been shown to trigger strong cellular immune responses to heterologous antigens expressed by the parasite in the inbred mouse model [1]. We studied the immune response induced by T. gondii as an effective vaccine vector in chickens and rabbits.

Results

T. gondii RH strain was engineered to express the yellow fluorescent protein (YFP) in the cytoplasm. A subcutaneous injection of the transgenic T. gondii YFP in chickens afforded partial protection against the infection of transgenic E. tenella YFP. T. gondii YFP induced low levels of antibodies to YFP in chickens, suggesting that YFP specific cellular immune response was probably responsible for the protective immunity against E. tenella YFP infection. The measurement of T-cell response and IFN-γ production further confirmed that YFP specific Th1 mediated immune response was induced by T. gondii YFP in immunized chickens. The transgenic T. gondii stimulated significantly higher YFP specific IgG titers in rabbits than in chickens, suggesting greater immunogenicity in a T. gondii susceptible species than in a resistant species. Priming with T. gondii YFP and boosting with the recombinant YFP can induce a strong anti-YFP antibody response in both animal species.

Conclusions

Our findings suggest that T. gondii can be used as an effective vaccine vector and future research should focus on exploring avirulent no cyst-forming strains of T. gondii as a live vaccine vector in animals.

Novel multiplex PCR using dual-priming oligonucleotides for detection and discrimination of the Mycobacterium tuberculosis complex and M. bovis BCG

We developed a novel multiplex PCR assay using dual-priming oligonucleotide primers targeting the RD1 gene for simultaneous identification of the Mycobacterium tuberculosis complex and M. bovis bacillus Calmette-Guérin (BCG). This assay would be useful both for detection of the M. tuberculosis complex and for differentiation of M. bovis BCG from pathogenic M. tuberculosis complex species.

Tubercular disease caused by Bacillus of Calmette-Guérin as a local adjuvant treatment of relapsing bladder carcinoma

Two (2) exemplary case reports of respiratory granulomatous infection caused by Bacillus of Calmette-Guérin (BCG), in patients who were repeatedly treated with local, intravesical adjuvant BCG therapy for a relapsing transitional bladder carcinoma, are outlined and discussed on the grounds of the cumbersome diagnostic and differential diagnostic process (especially when a prior tuberculosis and a concurrent chronic obstructive pulmonary disease are of concern), along with an updated literature revision. Only 4 cases of respiratory BCG-itis (pulmonary tuberculosis-like forms) have been reported, to date, to the best of our knowledge (2 of them following the bladder instillation of BCG). One (1) episode of ours represents the first described case with a dual, concomitant granulomatous localization of BCG-itis, also involving the genitourinary tract.

Disseminated Bacillus Calmette-Guerin infection after BCG vaccination

The BCG is administered to all the newborns at birth in Iran. Systemic adverse reactions to BCG vaccine such as osteomyelitis and disseminated BCG infection are rare. This is a retrospective study of 15 cases <72 months who were admitted with systemic syndrome compatible with disseminated mycobacterial disease during 2004-07. Disseminated BCG disease occurred in eight children younger than 6-months old and 12 patient younger than 12-months old. Twelve patients were male. Nine of 15 patients had well known primary immune deficiency disorders including severe combined immunodeficiency, chronic granulomatous disease; cell mediated immune defect and HIV infection. Nine (60%) cases had good response to four anti-mycobacterial drug therapy and interferon gamma. Disseminated BCG disease is a rare but devastating complication of BCG vaccination that should be considered in the appropriate clinical setting. Severe immune-compromised infants are at greatest risk and they respond poorly to standard therapies.

Assessment of Bacille Calmette-Guerin Vaccine Reaction in HIV-Exposed Thai Infants

We evaluated local reactions at 1, 2, and 4 months of age to bacille Calmette-Guérin vaccine given at birth to 1058 infants who were exposed to human immunodeficiency virus (HIV). No scar was discernible in 12 (12.4%) of 97 HIV-infected infants and 20 (2.1%) of 961 uninfected infants (relative risk, 5.9; 95% confidence interval, 3.0-11.8). This difference may reflect poorer immunogenicity in HIV-infected infants.

Vacina BCG contra tuberculose: efeito protetor e políticas de vacinação

OBJETIVO: A vacina BCG é utilizada desde 1921, embora ainda apresente controvérsias e aspectos não esclarecidos. O objetivo do artigo foi analisar aspectos relacionados ao efeito protetor da primeira e segunda doses da vacina BCG e as políticas de vacinação adotadas. MÉTODOS: Foi realizada revisão sistemática da literatura publicada em inglês e espanhol, abrangendo o período compreendido entre 1948 e 2006, na base PubMed. Os principais descritores utilizados foram BCG vaccine, BCG efficacy, BCG e tuberculosis. Os estudos foram agrupados por tipo de desenho, apresentando-se separadamente os principais resultados de ensaios clínicos, estudos de caso-controle e metanálises. RESULTADOS: O efeito protetor da primeira dose da vacina BCG contra a tuberculose na forma miliar ou na meningite é elevado. No entanto, os resultados são discordantes em relação à forma pulmonar, variando de ausência de efeito a níveis próximos a 80%. Estão sendo conduzidas pesquisas sobre novas vacinas candidatas a substituir a BCG ou serem utilizadas como reforço. CONCLUSÕES: Há evidências de que a segunda dose da BCG não aumenta o seu efeito protetor. Apesar de seus limites e da expectativa futura de nova vacina para tuberculose, a vacina BCG mantém-se como importante instrumento no controle dos efeitos danosos da doença, sobretudo em países com taxas de incidência médias e elevadas.

Mycobacterium tuberculosis infection in First Nations preschool children in Alberta: implications for BCG (bacille Calmette-Guérin) vaccine withdrawal

BACKGROUND

On April 1, 2004, BCG (bacille Calmette-Guérin), a tuberculosis (TB) control vaccine, was discontinued in all but four high-risk communities in Alberta. To confirm the safety of vaccine withdrawal, and for future planning, the annual risk of infection (ARI) was determined in preschool First Nations children.

METHODS

First Nations children born into reserve communities in Alberta between April 1, 1998 and March 31, 2004, and still living on reserve in 2004-2005, were identified. Health centre TB histories were validated by cross-referencing the birth cohort with the provincial TB Registry. Children that were not BCG vaccinated and not known to be tuberculin skin test (TST) positive underwent a TST. Birth cohort children were grouped as follows: (i) BCG vaccinated; (ii) BCG non-vaccinated, no TST; (iii) BCG non-vaccinated, TST; (iv) BCG vaccination status unknown. The ARI was calculated and the age and community characteristics of the groups were compared.

RESULTS

There were 8447 children in the 6-year birth cohort, 4699 (55.6%) vaccinated, 2696 (31.9%) non-vaccinated, and 1052 (12.5%) whose vaccination status was unknown. Of the non-vaccinated children, 1921 (71.3%) were tested and only 2 were TST positive. No other TST positive, BCG non-vaccinated children were identified in the TB Registry cross-match. The prevalence of infection in 2004-2005 was 0.1% and the ARI was 0.03%. The community risk of TB exposure was comparable in tuberculin-tested and non-tested BCG non-vaccinated children.

CONCLUSION

In low BCG-uptake First Nations communities in Alberta, the ARI is low and it is safe to withdraw BCG.

The benefits and risks of bacille Calmette-Guérin vaccination among infants at high risk for both tuberculosis and severe combined immunodeficiency: assessment by Markov model

BACKGROUND

Bacille Calmette-Guérin (BCG) vaccine is given to Canadian Aboriginal neonates in selected communities. Severe reactions and deaths associated with BCG have been reported among infants born with immunodeficiency syndromes. The main objective of this study was to estimate threshold values for severe combined immunodeficiency (SCID) incidence, above which BCG is associated with greater risk than benefit.

METHODS

A Markov model was developed to simulate the natural histories of tuberculosis (TB) and SCID in children from birth to 14 years. The annual risk of tuberculous infection (ARI) and SCID incidence were varied in analyses. The model compared a scenario of no vaccination to intervention with BCG. Appropriate variability and uncertainty analyses were conducted. Outcomes included TB incidence and quality-adjusted life years (QALYs).

RESULTS

In sensitivity analyses, QALYs were lower among vaccinated infants if the ARI was 0.1% and the rate of SCID was higher than 4.2 per 100,000. Assuming an ARI of 1%, this threshold increased to 41 per 100,000. In uncertainty analyses (Monte Carlo simulations) which assumed an ARI of 0.1%, QALYs were not significantly increased by BCG unless SCID incidence is 0. With this ARI, QALYs were significantly decreased among vaccinated children if SCID incidence exceeds 23 per 100,000. BCG is associated with a significant increase in QALYs if the ARI is 1%, and SCID incidence is below 5 per 100,000.

CONCLUSION

The possibility that Canadian Aboriginal children are at increased risk for SCID has serious implications for continued BCG use in this population. In this context, enhanced TB Control--including early detection and treatment of infection--may be a safer, more effective alternative.