[Risk factors for death caused by pneumonia in children younger than 1 year old in a metropolitan region of southeastern Brazil. A case- control study]

Effects of Paratuberculosis Vaccination at Different Ages in a Dairy Goat Herd: A 2-Year Follow-Up

Vaccination could be considered as an effective method for paratuberculosis control, although controversial, with a need for investigation in some aspects. The objective of this study was to evaluate the effect of vaccination, depending on the age of the animals, on their immune response, the reduction of paratuberculosis cases, mortality and culled animals in a commercial dairy herd. Goats from three different ages were immunized with the inactivated Gudair^® vaccine. Peripheral antibody and IFN-γ output were evaluated for 21 months post-vaccination (mpv) and intradermal skin tests (IDSTs) for tuberculosis, with avian- and bovine-purified protein derivatives (PPD), were carried out at 6 and at 18 mpv to evaluate the humoral and cellular immune peripheral responses, respectively. The number of dead or culled animals, regardless of the reason, was also monitored and the causes of death determined by pathological examination. A significant increase in the production of IFN-γ was observed in all the vaccinated groups when the blood samples were stimulated with avian PPD, from 3 mpv to 18 mpv, and with bovine PPD, between 3 and 21 mpv. Moreover, serum antibody levels increased between 3 and 21 mpv in all vaccinated groups. The highest levels were found in animals vaccinated at 5 months, and the lowest in adult individuals. No positive reactants to tuberculosis were found by intradermal skin test. No animal losses associated with clinical paratuberculosis were detected in any of the groups. The number of total culled animals was significantly lower in the vaccinated than in the unvaccinated groups, especially on 1.5-month-old vaccinated kids. These results suggest that vaccination of paratuberculosis, especially in young animals, could induce heterologous protection.

Fiction and Facts about BCG Imparting Trained Immunity against COVID-19

The Bacille Calmette-Guérin or BCG vaccine, the only vaccine available against Mycobacterium tuberculosis can induce a marked Th1 polarization of T-cells, characterized by the antigen-specific secretion of IFN-γ and enhanced antiviral response. A number of studies have supported the concept of protection by non-specific boosting of immunity by BCG and other microbes. BCG is a well-known example of a trained immunity inducer since it imparts ‘non-specific heterologous’ immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the recent pandemic. SARS-CoV-2 continues to inflict an unabated surge in morbidity and mortality around the world. There is an urgent need to devise and develop alternate strategies to bolster host immunity against the coronavirus disease of 2019 (COVID-19) and its continuously emerging variants. Several vaccines have been developed recently against COVID-19, but the data on their protective efficacy remains doubtful. Therefore, urgent strategies are required to enhance system immunity to adequately defend against newly emerging infections. The concept of trained immunity may play a cardinal role in protection against COVID-19. The ability of trained immunity-based vaccines is to promote heterologous immune responses beyond their specific antigens, which may notably help in defending against an emergency situation such as COVID-19 when the protective ability of vaccines is suspicious. A growing body of evidence points towards the beneficial non-specific boosting of immune responses by BCG or other microbes, which may protect against COVID-19. Clinical trials are underway to consider the efficacy of BCG vaccination against SARS-CoV-2 on healthcare workers and the elderly population. In this review, we will discuss the role of BCG in eliciting trained immunity and the possible limitations and challenges in controlling COVID-19 and future pandemics.

Effects of Mycobacterium bovis Calmette et Guérin (BCG) in oncotherapy: Bladder cancer and beyond

The Mycobacterium bovis Bacillus Calmette et Guérin (BCG) vaccine was generated in 1921 with the efforts of a team of investigators, Albert Calmette and Camille Guérin, dedicated to the determination to develop a vaccine against active tuberculosis (TB) disease. Since then, BCG vaccination is used globally for protection against childhood and disseminated TB; however, its efficacy at protecting against pulmonary TB in adult and aging populations is highly variable. Due to the BCG generated immunity, this vaccine later proved to have an antitumor activity; though the standing mechanisms behind are still unclear. Recent studies indicate that both innate and adaptive cell responses may play an important role in BCG eradication and prevention of bladder cancer. Thus, cells such as natural killer (NK) cells, macrophages, dendritic cells, neutrophils but also MHC-restricted CD4 and CD8 T cells and γδ T cells may play an important role and can be one the main effectors in BCG therapy. Here, we discuss the role of BCG therapy in bladder cancer and other cancers, including current strategies and their impact on the generation and sustainability of protective antitumor immunity against bladder cancer.

Is the BCG vaccine a useful tool against COVID-19?

The Bacillus Calmette–Guérin (BCG) vaccine has been used since 1921 initially for protection against tuberculosis. BCG acts through stimulation of cell-mediated adaptive immunity with activation of the Th1 cells and production of interferon gamma. Additionally, it is able to stimulate the immune system in a nonspecific manner, which results in effectiveness of the BCG against non-mycobacterial infections and in some malignant, autoimmune, and inflammatory diseases. Recently, its potential use in the fight against the coronavirus disease 2019 (COVID-19) pandemic has been suggested. This is based upon the concept of BCG-induced trained innate immunity—a memory-like response of the innate immune system that can realize greater protection in case of re-infection. This hypothesis represents a milestone in the potential use of the BCG vaccine in the fight with the novel coronavirus.

New live attenuated tuberculosis vaccine MTBVAC induces trained immunity and confers protection against experimental lethal pneumonia

Among infectious diseases, tuberculosis is the leading cause of death worldwide, and represents a serious threat, especially in developing countries. The protective effects of Bacillus Calmette-Guerin (BCG), the current vaccine against tuberculosis, have been related not only to specific induction of T-cell immunity, but also with the long-term epigenetic and metabolic reprogramming of the cells from the innate immune system through a process termed trained immunity. Here we show that MTBVAC, a live attenuated strain of Mycobacterium tuberculosis, safe and immunogenic against tuberculosis antigens in adults and newborns, is also able to generate trained immunity through the induction of glycolysis and glutaminolysis and the accumulation of histone methylation marks at the promoters of proinflammatory genes, facilitating an enhanced response after secondary challenge with non-related bacterial stimuli. Importantly, these findings in human primary myeloid cells are complemented by a strong MTBVAC-induced heterologous protection against a lethal challenge with Streptococcus pneumoniae in an experimental murine model of pneumonia.

Mycobacterium tuberculosis has been causing infections in our species and our ancestors for at least thousands of years. Still today, the numbers of people affected by tuberculosis are alarming with more than 1,4 million deaths per year, representing the first cause of death by infectious disease worldwide. Despite immense research efforts, Bacille Calmette-Guerin (BCG), a vaccine based on a live attenuated form of Mycobacterium bovis that was developed one century ago, remains the only licensed vaccine against tuberculosis. Several independent works have shown that BCG induces protection not only against tuberculosis, but also against other infections through the induction of epigenetic and metabolic effects in the cells of the innate immune system, what has been termed trained immunity. Here we describe how MTBVAC, a new vaccine against tuberculosis based on a genetically modified form of the human pathogen Mycobacterium tuberculosis, that has shown similar safety profiles and improved protection than BCG in preclinical studies, is able to induce trained immunity in human cells and grant protection against a heterologous model of pneumococcal infection in mice. These results underline the potential of MTBVAC as a candidate for universal vaccination against tuberculosis or treatment against bladder cancer, representing a potential alternative to the current BCG vaccines.

Beyond memory T cells: mechanisms of protective immunity to tuberculosis infection

Tuberculosis (TB) is a serious infectious disease caused by infection with Mycobacterium tuberculosis, and kills more people annually than any other single infectious agent. Although a vaccine is available, it is only moderately effective and an improved vaccine is urgently needed. The ability to develop a more effective vaccine has been thwarted by a lack of understanding of the mechanism of vaccine-induced immune protection. Over recent decades, many novel TB vaccines have been developed and almost all have aimed to generate memory CD4 T cells. In this review, we critically evaluate evidence in the literature that supports the contention that memory CD4 T cells are the prime mediators of vaccine-induced protection against TB. Because of the lack of robust evidence supporting memory CD4 T cells in this role, the potential for B-cell antibody and "trained" innate cells as alternative mediators of protective immunity is explored.

Distribuição espacial das taxas de internação de crianças por pneumonia no Sistema Único de Saúde, nos municípios do estado de São Paulo

RESUMO: Objetivo: Identificar padrões espaciais na distribuição das taxas de internação de crianças por pneumonia no estado de São Paulo, no período de 2009 a 2013. Métodos : Estudo ecológico exploratório com dados obtidos do Departamento de Informática do Sistema Único de Saúde (DATASUS) de internações por pneumonia em crianças relativas aos municípios do estado de São Paulo de 2009 a 2013, dados de escolaridade materna e renda familiar; e foram criadas taxas por mil crianças e inseridas numa base digital de municípios obtida do Instituto Brasileiro de Geografia e Estatística. Foram construídos mapas temáticos, de Kernel e de Moran para as taxas de internação e calculados os índices de Moran. Foi utilizado o programa TerraView para a análise espacial. Resultados : Foram internadas 43.809 crianças no período. A taxa média por município foi de 11,51 (DP = 8,62). O índice de Moran foi de 0,21 (p = 0,01). Há aglomerados nas regiões norte, noroeste, centro-oeste e sudoeste; o mapa de Kernel mostra densidade maior de taxas no noroeste e centro-oeste do estado; e o mapa de Moran identificou 39 municípios que merecem atenção por parte dos gestores municipais e regionais. Conclusões : O geoprocessamento permitiu identificar regiões com maiores taxas de internação por pneumonia e também municípios que merecem prioridade de intervenção.

Determinants of BCG scarification among children in rural Guinea-Bissau: A prospective cohort study

Background: Bacillus Calmette-Guérin (BCG) vaccination may have beneficial non-specific effects on child survival, the effects being stronger for children developing a scar. In a prospective cohort study, we examined determinants for not developing a BCG scar within 6 months of vaccination.

Methods: Bandim Health Project (BHP) runs a Health and Demographic Surveillance System site in rural Guinea-Bissau. BHP provides BCG at monthly visits. We studied determinants for not developing a BCG scar using binomial regression models to obtain relative risks (RR).

Results: From May 2012 until October 2014, BHP nurses vaccinated 2415 infants with BCG. We assessed BCG scar between 6 and 12 months of age for 2156 (89%) of these children and 2115 (98%) had developed a scar. In comparison, among 785 children BCG vaccinated elsewhere, 622 (79%) had a scar, the RR of not having a scar being 10.91 (7.52-15.85) compared with children vaccinated by BHP.

Among children vaccinated by BHP, those receiving the Russian BCG strain were more likely not to develop a scar (RR = 2.98 (1.52–5.81)) compared with children receiving Danish BCG strain. Children with no post-injection wheal or a wheal <3 mm were more likely to not develop a scar (RR = 9.05 (3.69–22.20) and RR = 4.74 (1.96–11.45), respectively). Nutritional status and socioeconomic status were not associated with scarification.

Conclusion: Vaccination technique and vaccine strain were associated with BCG scar development while nutritional status and socioeconomic status were not. Scarring rate may therefore be a better indicator of vaccination programme performance than coverage.

Childhood pneumonia and crowding, bed-sharing and nutrition: a case-control study from The Gambia

SETTING

Greater Banjul and Upper River Regions, The Gambia.

OBJECTIVE

To investigate tractable social, environmental and nutritional risk factors for childhood pneumonia.

DESIGN

A case-control study examining the association of crowding, household air pollution (HAP) and nutritional factors with pneumonia was undertaken in children aged 2-59 months: 458 children with severe pneumonia, defined according to the modified WHO criteria, were compared with 322 children with non-severe pneumonia, and these groups were compared to 801 neighbourhood controls. Controls were matched by age, sex, area and season.

RESULTS

Strong evidence was found of an association between bed-sharing with someone with a cough and severe pneumonia (adjusted OR [aOR] 5.1, 95%CI 3.2-8.2, P < 0.001) and non-severe pneumonia (aOR 7.3, 95%CI 4.1-13.1, P < 0.001), with 18% of severe cases estimated to be attributable to this risk factor. Malnutrition and pneumonia had clear evidence of association, which was strongest between severe malnutrition and severe pneumonia (aOR 8.7, 95%CI 4.2-17.8, P < 0.001). No association was found between pneumonia and individual carbon monoxide exposure as a measure of HAP.

CONCLUSION

Bed-sharing with someone with a cough is an important risk factor for severe pneumonia, and potentially tractable to intervention, while malnutrition remains an important tractable determinant.

Development of BCG Scar and Subsequent Morbidity and Mortality in Rural Guinea-Bissau

BACKGROUND

Previous studies have found that BCG vaccination has nonspecific beneficial effects on child survival, especially among children who developed a BCG scar. These studies have mostly been done in settings with a high scar frequency. In rural Guinea-Bissau, many children do not develop a scar; we tested the hypothesis that among BCG-vaccinated children, a vaccination scar was associated with lower mortality and fewer hospital admissions.

METHODS

During 2009-2011, children <5 years of age in villages followed by Bandim Health Project's demographic surveillance system had their scar status assessed at semiannual visits. We compared mortality and hospital admission rates of scar-positive and scar-negative BCG-vaccinated children during 6 months of follow-up in Cox proportional hazards models.

RESULTS

Among 15 911 BCG-vaccinated children, only 52% had a scar. There were 106 non-injury-related deaths among scar-positive children and 137 among scar-negative children. The mortality rate ratio (MRR) was 0.74 (95% confidence interval [CI], .56-.96) overall; 0.48 (95% CI, .26-.90) in infancy, 0.69 (95% CI, .45-1.05) in the second year of life, and 0.89 (95% CI, .61-1.31) in the third-fifth year of life. The association between scar positivity and lower mortality differed significantly by cause of death and was strongest for respiratory infections (MRR, 0.20 [95% CI, .07-.55]). There were 99 hospital admissions among scar-positive children and 125 admissions among scar-negative children, resulting in an incidence rate ratio of 0.74 (95% CI, .60-.92).

CONCLUSIONS

Among BCG-vaccinated children in a setting with low scar prevalence, having a scar is associated with lower mortality and morbidity. BCG scar prevalence may be an important marker of vaccination program quality.

Autophagy controls BCG-induced trained immunity and the response to intravesical BCG therapy for bladder cancer

The anti-tuberculosis-vaccine Bacillus Calmette-Guérin (BCG) is the most widely used vaccine in the world. In addition to its effects against tuberculosis, BCG vaccination also induces non-specific beneficial effects against certain forms of malignancy and against infections with unrelated pathogens. It has been recently proposed that the non-specific effects of BCG are mediated through epigenetic reprogramming of monocytes, a process called trained immunity. In the present study we demonstrate that autophagy contributes to trained immunity induced by BCG. Pharmacologic inhibition of autophagy blocked trained immunity induced in vitro by stimuli such as β–glucans or BCG. Single nucleotide polymorphisms (SNPs) in the autophagy genes ATG2B (rs3759601) and ATG5 (rs2245214) influenced both the in vitro and in vivo training effect of BCG upon restimulation with unrelated bacterial or fungal stimuli. Furthermore, pharmacologic or genetic inhibition of autophagy blocked epigenetic reprogramming of monocytes at the level of H3K4 trimethylation. Finally, we demonstrate that rs3759601 in ATG2B correlates with progression and recurrence of bladder cancer after BCG intravesical instillation therapy. These findings identify a key role of autophagy for the nonspecific protective effects of BCG.

Next to its effects against tuberculosis, BCG vaccination also induces non-specific beneficial effects on immune cells to increase their ability to control unrelated pathogens. It has been recently proposed that the non-specific effects of BCG are mediated through epigenetic reprogramming of monocytes, a process called trained immunity. Little is known regarding the intracellular events controlling its induction. In this study we identified autophagy as a key player in trained immunity. Pharmacological inhibition of autophagy as well as polymorphisms in autophagy-related genes blocked BCG-induced trained immunity. Furthermore, BCG vaccine is also used to treat bladder cancer. Genetic polymorphisms in autophagy-related genes correlated with progression and recurrence of bladder cancer after treatment with BCG therapy. These findings open new possibilities for improvement of future BCG-based vaccines to be used against infections and malignancies.

BCG coverage and barriers to BCG vaccination in Guinea-Bissau: an observational study

BACKGROUND

BCG vaccination is recommended at birth in low-income countries, but vaccination is often delayed. Often 20-dose vials of BCG are not opened unless at least ten children are present for vaccination ("restricted vial-opening policy"). BCG coverage is usually reported as 12-month coverage, not disclosing the delay in vaccination. Several studies show that BCG at birth lowers neonatal mortality. We assessed BCG coverage at different ages and explored reasons for delay in BCG vaccination in rural Guinea-Bissau.

METHODS

Bandim Health Project (BHP) runs a health and demographic surveillance system covering women and their children in 182 randomly selected village clusters in rural Guinea-Bissau. BCG coverage was assessed for children born in 2010, when the restricted vial-opening policy was universally implemented, and in 2012-2013, where BHP provided BCG to all children at monthly visits in selected intervention regions. Factors associated with delayed BCG vaccination were evaluated using logistic regression models. Coverage between intervention and control regions were evaluated in log-binomial regression models providing prevalence ratios.

RESULTS

Among 3951 children born in 2010, vaccination status was assessed for 84%. BCG coverage by 1 week of age was 11%, 38% by 1 month, and 92% by 12 months. If BCG had been given at first contact with the health system, 1-week coverage would have been 35% and 1-month coverage 54%. When monthly visits were introduced in intervention regions, 1-month coverage was higher in intervention regions (88%) than in control regions (51%), the prevalence ratio being 1.74 (1.53-2.00). Several factors, including socioeconomic factors, were associated with delayed BCG vaccination in the 2010-birth cohort. When BCG was available at monthly visits these factors were no longer associated with delayed BCG vaccination, only region of residence was associated with delayed BCG vaccination.

CONCLUSION

BCG coverage during the first months of life is low in Guinea-Bissau. Providing BCG at monthly vaccination visits removes the risk factors associated with delayed BCG vaccination.

Acute lower respiratory infection among Bacille Calmette-Guérin (BCG)-vaccinated children

OBJECTIVE

To determine whether Bacille Calmette-Guerin (BCG) vaccination is linked to the risk of acute lower respiratory infection (ALRI) among children <5 years of age.

METHODS

Data from Macro International Demographic and Health Surveys and United Nations Children's Fund Multiple Indicator Cluster Surveys were used to identify a primary cohort of 58,021 children in 19 countries (2005-2010) and a secondary cohort of 93,301 children in 18 countries (2000-2007). Information was collected by trained interviewers during home visits using standardized questionnaires, review of vaccination health cards, and measurement of health indicators.

RESULTS

BCG vaccination was associated with a 17% to 37% risk reduction for suspected ALRI in both cohorts. The only vaccine or vitamin supplement to modify the effect of BCG was diphtheria-tetanus-pertussis (DTP; P < .001). The order in which the vaccines were first received was central to this phenomena (BCG before DTP, adjusted/propensity score-weighted relative risk [apRR]: 0.79, 95% confidence interval [CI]: 0.70-0.89; BCG with DTP, apRR: 0.82, 95% CI: 0.71-0.94; and BCG after DTP, apRR: 1.00, 95% CI: 0.87-1.13) but not number of DTP doses received. Other modifiers included vaccine strain used in immunization programs, chlorinating drinking water, using wood-burning fuel cook stoves, and owning livestock.

CONCLUSIONS

Children vaccinated with BCG had a significantly lower risk of suspected ALRI. Clarification is needed as to whether this is due to reductions in the underlying risk of tuberculosis or ALRI per se.

Long-lasting effects of BCG vaccination on both heterologous Th1/Th17 responses and innate trained immunity

We have recently shown that BCG (Bacillus Calmette-Guérin) vaccination in healthy volunteers induces epigenetic reprogramming of monocytes, leading to increased cytokine production in response to nonrelated pathogens for up to 3 months after vaccination. This phenomenon was named 'trained immunity'. In the present study we assessed whether BCG was able to induce long-lasting effects on both trained immunity and heterologous T helper 1 (Th1) and Th17 immune responses 1 year after vaccination. The production of TNFα and IL-1β to mycobacteria or unrelated pathogens was higher after 2 weeks and 3 months postvaccination, but these effects were less pronounced 1 year after vaccination. However, monocytes recovered 1 year after vaccination had an increased expression of pattern recognition receptors such as CD14, Toll-like receptor 4 (TLR4) and mannose receptor, and this correlated with an increase in proinflammatory cytokine production after stimulation with the TLR4 ligand lipopolysaccharide. The heterologous production of Th1 (IFN-γ) and Th17 (IL-17 and IL-22) immune responses to nonmycobacterial stimulation remained strongly elevated even 1 year after BCG vaccination. In conclusion, BCG induces sustained changes in the immune system associated with a nonspecific response to infections both at the level of innate trained immunity and at the level of heterologous Th1/Th17 responses.

Proposta de atuação da fisioterapia na saúde da criança e do adolescente: uma necessidade na atenção básica

Objetivo: elaborar uma proposta de assistência fisioterapêutica na rede básica de saúde objetivando sistematizar esse serviço para a saúde da criança e do adolescente. Método: revisão bibliográfica/pesquisa nas bases de dados Scielo, Lilacs e Medline. Resultados: o fisioterapeuta não apenas restaura, desenvolve e conserva a capacidade física do paciente, como também previne doenças e promove orientações. Assim, propõe-se sua atuação com base em três estratégias: orientação, assistência e acompanhamento. Conclusão: o fisioterapeuta na atenção primária pode efetivar sua integração na equipe multiprofissional das UBS, no apoio matricial e programas de saúde da família.

Bacille Calmette-Guerin induces NOD2-dependent nonspecific protection from reinfection via epigenetic reprogramming of monocytes

Adaptive features of innate immunity, recently described as "trained immunity," have been documented in plants, invertebrate animals, and mice, but not yet in humans. Here we show that bacille Calmette-Guérin (BCG) vaccination in healthy volunteers led not only to a four- to sevenfold increase in the production of IFN-γ, but also to a twofold enhanced release of monocyte-derived cytokines, such as TNF and IL-1β, in response to unrelated bacterial and fungal pathogens. The enhanced function of circulating monocytes persisted for at least 3 mo after vaccination and was accompanied by increased expression of activation markers such as CD11b and Toll-like receptor 4. These training effects were induced through the NOD2 receptor and mediated by increased histone 3 lysine 4 trimethylation. In experimental studies, BCG vaccination induced T- and B-lymphocyte-independent protection of severe combined immunodeficiency SCID mice from disseminated candidiasis (100% survival in BCG-vaccinated mice vs. 30% in control mice). In conclusion, BCG induces trained immunity and nonspecific protection from infections through epigenetic reprogramming of innate immune cells.

Doenças respiratórias agudas: um estudo das desigualdades em saúde

Apresentam-se as desigualdades em saúde valendo-se das doenças respiratórias agudas na infância na área de abrangência de um centro de saúde na cidade de São Paulo, Brasil, para subsidiar o planejamento local de ações de promoção da saúde. O trabalho se fundamentou em estudos ecológicos que utilizam a área geográfica como unidade de análise, permitindo a comparação de indicadores de saúde e sócio-econômicos mediante dados censitários. Foram construídos indicadores de "inserção social" e de "qualidade do domicílio", gerando o "índice potencial de exposição" que reflete as condições de risco para o adoecimento por agravos respiratórios. O tratamento estatístico incluiu o agrupamento pela técnica de cluster. Foram identificados quatro grupos sociais homogêneos nas condições de risco para as doenças respiratórias agudas. Os grupos III e IV - com as piores condições sócio-econômicas - mostraram diferenciais importantes em relação aos grupos I e II. Os diferenciais de mortes por pneumonia encontrados, sugerem iniqüidades em saúde. Os resultados permitiram a localização geográfica de maior e menor concentração das carências relativas às condições de vida e a comparação entre os setores censitários para o reconhecimento de necessidades distintas, que subsidiem propostas para a articulação intersetorial.

Tuberculin reaction, BCG scar, and lower female mortality

BACKGROUND

Recent studies have suggested that bacille Calmette-Guérin (BCG) immunization may have a nonspecific beneficial effect on infant survival and that the effect may be more pronounced among girls. In a prospective birth cohort, we examine whether a positive tuberculin skin test and BCG scar in response to BCG immunization were related to better overall survival in Guinea-Bissau and, if so, whether the effect was sex-specific.

METHODS

Skin tests and BCG scarring were monitored at ages 2 months (n = 2332) and 6 months (n = 1817) in children born from March 2000 to July 2002. A tuberculosis (TB) surveillance system allowed us to exclude from the analysis children with likely TB exposure. The children were followed for survival until 18 months of age.

RESULTS

Among children with a tuberculin skin test at 2 and 6 months of age, the mortality rate ratio for skin test reactors (>1 mm) versus nonreactors (0-1 mm) was 0.54 (95% confidence interval = 0.30-0.99). Comparing children with and without a BCG scar, the ratio was 0.55 (0.31-0.96). The effect of a skin test reaction or a BCG scar seemed stronger among girls; for those with positive reaction, the mortality ratio was 0.31 (0.11-0.88) among girls and 0.84 (0.39-1.82) among boys; and for BCG scar, the results were 0.41 (0.21-0.82) and 0.88 (0.34-2.30), respectively.

CONCLUSIONS

A good response to BCG vaccination is related to lower child mortality. The effect seems most pronounced among girls. The findings may have implications for future vaccine trials and policy.

Beneficial non-targeted effects of BCG--ethical implications for the coming introduction of new TB vaccines

Non-targeted effect of BCG: Several recent studies suggest that BCG has beneficial non-targeted effects on general child survival in low-income countries. Studies of the effect of BCG on morbidity in humans are scarce; some found a positive effect of BCG and others show no effect. Non-targeted effects of vaccines-possible bias and confounding: The major argument against comparing vaccinated and unvaccinated groups is that there is a beneficial social selection bias for vaccinated children-the "Healthy vaccinee effect". However, controlling for various social and health-related background factors in the survival analyses had no effect on the estimates, making this source of bias less likely. A more powerful argument that the findings are not due to the healthy vaccinee effect is that differential non-targeted effects of other vaccines have been observed; diphteria-tetanus-pertussiss vaccination has marked negative effects on child survival, whereas measles vaccine has a positive effect in several studies. Several studies have shown better survival for children reacting to their BCG vaccination with a BCG scar or tuberculin skin test reaction (TST). It could be argued that the reacting children were immunologically stronger and therefore more likely to survive-the "Healthy reactor effect". However, recent findings show that a BCG scar and a TST reaction depend to a large extent on the vaccination technique. Hence, the BCG responses may reflect a true vaccine effect and not merely the health status of the children. Since HIV-1 has been shown to suppress both TST and BCG scar reaction in response to BCG, it is an obvious contributor to the healthy reactor effect, but excluding deaths of children with HIV-1 infection from analysis did not affect the beneficial effect of having a positive TST. Excluding children exposed to tuberculosis (TB) in the household did not affect the estimates either. Furthermore, there are strong sex-differential effects of BCG in both mortality and morbidity data, BCG being more beneficial for girls. These observations cannot consistently be explained by the healthy vaccinee or healthy reactor effects. Ethical implications: For future TB-vaccine studies, these findings imply that: These recommendations might be considered to delay or to be a too large obstacle for the development and trials of new TB vaccines. However, most of the non-targeted beneficial effects of BCG have been observed in children below 2 years of age, which is not a long follow-up time in a TB-vaccine trial. Furthermore, considering the difficulty in setting the TB diagnose in children and the lack of reliable TB-protection markers, it does not seem unreasonable to argue for monitoring of general morbidity and survival in future TB-vaccine trials.

Bacillus Calmette-Guérin vaccination and infant mortality

When the bacillus Calmette-Guérin (BCG) vaccine was introduced in the 1920s, it was suggested that BCG occasionally had nonspecific beneficial effects on mortality beyond the specific protection against tuberculosis. Considering that BCG has since then become the most used vaccine in the world, surprisingly few studies have been undertaken into the effect of BCG on general mortality and morbidity. Recent studies suggest that BCG has beneficial nontargeted effects on general infant morbidity and mortality in low-income countries, often with the most pronounced effect among girls. These observational findings are supported by early trials in which children were randomized or alternated to BCG vaccination. Furthermore, a BCG scar and a positive tuberculin reaction are related to better survival among BCG-vaccinated children in low-income countries, especially for girls. The findings are not explained by frailty bias, in other words, that healthy children are more likely to receive BCG vaccination. A nonspecific, gender-differential effect of BCG on general infant mortality may have large implications for tuberculosis vaccine research and routine vaccination policy.

BCG vaccination scar associated with better childhood survival in Guinea-Bissau

BACKGROUND

Recent studies have suggested that Bacille Calmette-Guerin (BCG) vaccination may have a non-specific beneficial effect on infant survival and that a BCG scar may be associated with lower child mortality. No study has previously examined the influence of BCG vaccination on cause of death.

METHODS

Two cohorts (A and B) were used to describe the mortality pattern for children with and without BCG scar and to determine specific causes of death. In cohort A (n = 1813), BCG scar was assessed at 6 months of age and as previously described children with a BCG scar had lower mortality over the next 12 months than children with no BCG scar. In cohort B, 1617 children aged 3 months to 5 years of age had their BCG scar status assessed in a household-based survey and mortality was assessed during a 12-month period. Causes of death were determined by verbal autopsy (VA) and related to BCG scar status in a cause-specific hazard function.

RESULTS

Controlling for background factors associated with mortality, there was lower mortality for children with a BCG scar than without in cohort B, the mortality ratio (MR) being 0.45 (95% CI 0.21-0.96). Exclusion of children exposed to TB did not have any impact on the result. In a combined analysis of cohorts A and B, the MR was 0.43 (95% CI 0.28-0.65) controlling for background factors. There were no large differences in distribution of the five major causes of death (malaria, pneumonia, acute diarrhoea, chronic diarrhoea, and meningitis/encephalitis) according to BCG scar status in the two cohorts. Having a BCG scar significantly reduced the risk of death from malaria [MR 0.32 (95% CI 0.13-0.76)].

CONCLUSIONS

A BCG scar is a marker of better survival among children in countries with high child mortality. BCG vaccination may affect the response to several major infections including malaria.

The etiology of extensive pleural effusions with troublesome clinical course among children

CONTEXT

In São Paulo, pneumonia is the main infectious cause of death among children. Parapneumonic pleural effusion is a possible complication and has to be treated surgically when the patient does not respond to antibiotics.

OBJECTIVE

Assessment of the etiology of complicated parapneumonic pleural effusions that needed surgical intervention.

TYPE OF STUDY

Retrospective study.

SETTING

University hospital of the University of São Paulo.

METHOD

Analysis of 4,000 files on children hospitalized with pneumonia from November 1986 to November 1996 had shown that 115 of these children presented a total of 117 cases of pleural empyema that required surgical procedures. The children's clinical condition was assessed in relation to radiological findings and to their nutrition and immunization status. Previous antimicrobial therapy and pleural effusion bacterioscopy were also evaluated.

RESULTS

Streptococcus pneumoniae was the agent found most commonly, as frequently in blood cultures as in pleural effusions.

DISCUSSION

Data on vaccination coverage, birth weight and nutritional status are analyzed and compared to other publications. We observed that pleural effusion has a high potential for discomfort, and in most cases it is not a complication of the first pulmonary disease episode. Previous use of antibiotics interfered with culture positivity. The agent most frequently found was Streptococcus pneumoniae, which is in accordance with the findings from other authors. Nonetheless, the antibiotics used to treat the patients after the procedure were the same used in non-complicated pneumonias, which has led us to conclude that the worse outcome in this cases was not due to drug resistance.

CONCLUSION

The bacteriological profile in our series of complicated pneumonia cases was similar to what has been described for non-complicated pneumonia cases. Future studies will be necessary to determine why these children presented a worse outcome.

Crowding: risk factor or protective factor for lower respiratory disease in young children?

Background

To study the effects of household crowding upon the respiratory health of young children living in the city of São Paulo, Brazil.

Methods

Case-control study with children aged from 2 to 59 months living within the boundaries of the city of São Paulo. Cases were children recruited from 5 public hospitals in central São Paulo with an acute episode of lower respiratory disease. Children were classified into the following diagnostic categories: acute bronchitis, acute bronchiolitis, pneumonia, asthma, post-bronchiolitis wheezing and wheezing of uncertain aetiology. One control, crudely matched to each case with regard to age (<2, 2 years old or more), was selected among healthy children living in the neighborhood of the case.

All buildings were surveyed for the presence of environmental contaminants, type of construction and building material. Plans of all homes, including measurements of floor area, height of walls, windows and solar orientation, was performed. Data were analysed using conditional logistic regression.

Results

A total of 313 pairs of children were studied. Over 70% of the cases had a primary or an associated diagnosis of a wheezing illness. Compared with controls, cases tended to live in smaller houses with less adequate sewage disposal. Cases and controls were similar with respect to the number of people and the number of children under five living in the household, as well the number of people sharing the child's bedroom.

After controlling for potential confounders, no evidence of an association between number of persons sharing the child's bedroom and lower respiratory disease was identified when all cases were compared with their controls. However, when two categories of cases were distinguished (infections, asthma) and each category compared separately with their controls, crowding appeared to be associated with a 60% reduction in the incidence of asthma but with 2 1/2-fold increase in the incidence of lower respiratory tract infections (p = 0.001).

Conclusion

Our findings suggest that household crowding places young children at risk of acute lower respiratory infection but may protect against asthma. This result is consistent with the hygiene hypothesis.

Fatores ambientais e hospitalizações em crianças menores de cinco anos com infecção respiratória aguda

Considerando a hospitalização como um indicador de gravidade da Infecção Respiratória Aguda (IRA), objetiva-se estudar a associação de alguns fatores ambientais com a necessidade de tratamento hospitalar em crianças com diagnóstico de IRA. Foram analisados todos os prontuários de atendimento do Pronto Socorro Municipal de Cuiabá, das crianças menores de cinco anos, de ambos os sexos, agrupados por mês do atendimento. Obedecendo às características climáticas da região, dois períodos climáticos foram levados em conta: seco (maio a outubro) e chuvoso (novembro a abril). As variáveis: temperatura, umidade relativa do ar, o número de focos de calor (queimadas) foram cotejadas. A prevalência da IRA foi 49,8%; a necessidade de internação alcançou 7,6%, com percentual de internações maior no período seco. Conclui-se que o período seco e a umidade relativa do ar estão associados com as hospitalizações das crianças estudadas.

[Geoprocessing and health promotion: social and environmental inequalities, Brazil]

OBJECTIVE

To characterize social inequalities that represent risk conditions for respiratory tract diseases in children and to describe geoprocessing techniques to identify homogeneous social groups and intervention actions for health promotion.

METHODS

The study area comprised the surroundings of a health school center in the city of S o Paulo. Based on 1991 census, housing data on 49 census units in the study area were statistically analyzed and it was obtained the mean of characteristic social and environment variables in these units. Together with local representatives, variables were selected that made up composite indicators related to social insertion and housing quality to allow identifying different conditions of potential exposure to respiratory tract diseases. Using geoprocessing techniques, four homogeneous groups were identified in terms of potential exposure to risk conditions for respiratory diseases.

RESULTS

It was obtained a spatial configuration of the groups reflecting different needs in the study area. The methodological instruments used revealed to be important for the development of local actions to be implemented in services that operate in specific geographical areas.

CONCLUSIONS

The study contributed to the identification of risk conditions in the health center area, making it possible the joint and inter-sector discussion of conditions related to respiratory tract diseases in children, aiming at promoting equity and improving child health.

Effects of socioeconomic status on presentation with acute lower respiratory tract disease in children in Salvador, Northeast Brazil

Two different socioeconomic groups of children with pneumonia were studied, and their clinical and demographic aspects were evaluated. The diagnosis of pneumonia was based on findings of cough and tachypnea, or on crackles on auscultation or on radiologically confirmed infiltrate. This was a prospective cross-sectional study conducted at the Professor Hosannah de Oliveira Pediatric Center, which cares for children of lower socioeconomic status (PHOPC), and at one private hospital which cares for children from middle to high socioeconomic status (Aliança Hospital, AH). Demographics and clinical differences were assessed by the Pearson chi-square test or Fisher's exact test as appropriate; means of continuous variables were compared by Mann-Whitney U-test. In a 26-month period, 3,431 cases were recruited. The 2,476 cases identified at the PHOPC were younger than the 955 identified at AH (2.2 +/- 2.3 vs. 4.5 +/- 3.1 years, P < 0.0001) and had higher scores for severity (3.5 +/- 1.5 vs. 2.7 +/- 1.7, P < 0.0001), duration of hospitalization (days) (10.9 +/- 12.1 vs. 6.2 +/- 7, P < 0.0001), frequency of tobacco smoker in the household (48% vs. 31%, P < 0.0001), cardiopathy (15.3% vs. 5.9%, P = 0.003), fever (44.4% vs. 36.3%, P = 0.0001), tachypnea (67.6% vs. 32.3%, P < 0.0001), crackles (69.5% vs. 64.9%, P = 0.02), somnolence (19.9% vs. 10.4%, P < 0.0001), malnutrition (13.7% vs. 5%, P < 0.0001), hospitalization rate (27.4% vs. 22.5%, P = 0.003), and death (0.9% vs. 0.1%, P = 0.009). However, other features were more frequent among AH cases: parent's university level of education (38.2% vs. 1.0%, P < 0.0001), underlying chronic illness (40.6% vs. 28.5%, P < 0.0001), asthma (62.7% vs. 50.8%, P = 0.01), rhinitis (9.2% vs. 0.4%, P < 0.0001), previous use of antibiotics (34.3% vs. 27.1%, P = 0.001), and wheezing (53.1% vs. 42.2%, P < 0.0001). Children of lower socioeconomic status have more serious lower respiratory tract disease, whereas children with pneumonia of middle to high socioeconomic status have more allergic diseases (rhinitis, asthma) and wheezing.

[Association between socioeconomic factors and infant deaths due to diarrhea, pneumonia, and malnutrition in a metropolitan area of Southeast Brazil: a case-control study]

A population-based case-control study was carried out to identify determinant factors for post-neonatal infant deaths due to diarrhea, pneumonia, and malnutrition in Greater Metropolitan Belo Horizonte, Southeast Brazil. From May 1, 1991, to April 30, 1992, 511 post-neonatal deaths due to diarrhea, pneumonia, and malnutrition were selected after investigation of medical records to validate cause of death. Of this total, 396 deaths were compared to a neighborhood control group, matched for age. The study was carried out in a low-income area with a high proportion of families living in shantytowns. The article discusses the methodology and selected socioeconomic factors. Logistic regression analysis indicated that number of household appliances, mother's and father's education, and mother's marital and work status were significantly associated with risk of infant death, i.e., they were determinants of infant deaths due to avoidable causes.

Routine vaccinations and child survival: follow up study in Guinea-Bissau, West Africa

OBJECTIVE

To examine the association between routine childhood vaccinations and survival among infants in Guinea-Bissau.

DESIGN

Follow up study.

PARTICIPANTS

15 351 women and their children born during 1990 and 1996.

SETTING

Rural Guinea-Bissau.

MAIN OUTCOME MEASURES

Infant mortality over six months (between age 0-6 months and 7-13 months for BCG, diphtheria, tetanus, and pertussis, and polio vaccines and between 7-13 months and 14-20 months for measles vaccine).

RESULTS

Mortality was lower in the group vaccinated with any vaccine compared with those not vaccinated, the mortality ratio being 0.74 (95% confidence interval 0.53 to 1.03). After cluster, age, and other vaccines were adjusted for, BCG was associated with significantly lower mortality (0.55 (0.36 to 0.85)). However, recipients of one dose of diphtheria, tetanus, and pertussis or polio vaccines had higher mortality than children who had received none of these vaccines (1.84 (1.10 to 3.10) for diphtheria, tetanus, and pertussis). Recipients of measles vaccine had a mortality ratio of 0.48 (0.27 to 0.87). When deaths from measles were excluded from the analysis the mortality ratio was 0.51 (0.28 to 0.95). Estimates were unchanged by controls for background factors.

CONCLUSIONS

These trends are unlikely to be explained exclusively by selection biases since different vaccines were associated with opposite tendencies. Measles and BCG vaccines may have beneficial effects in addition to protection against measles and tuberculosis.

[Incidence and risk factors for diarrhoea and acute respiratory infections in urban communities of Pernambuco, Brazil]

Magnitude and distribution of Diarrhoea and Acute Respiratory Infections (ARI) in children were studied within a larger broader research that focused on health education. Two household surveys were conducted in a sample of families with at least one child under five years of Recife and Olinda in April-May 1992 and 1994. The total number of children studied was 5,436. The estimated adjusted annual incidence rate (AAIR) of diarrhoea was 2.7 episodes per child. The two-week incidence rate of diarrhoea was 10.2% for both years. Risk factors associated with higher incidence of diarrhoea were age (under two years), lack of sanitation facilities, and absence of electrical appliances in the household. Estimated AAIR of ARI was 9. 5 episodes per child. The two-week incidence rate of ARI was 41.0% in 1992 and 32.6% in 1994. Majority of ARIs affected the upper respiratory tract (75.9%). The only factor consistently associated with a higher risk of ARI was age (under three years). Study results indicate that both pathologies are still an important health problem for children under five in Pernambuco. In particular, in the case of diarrhoea the need for improving the access to basic services, such as water supply and sewage system is urgently needed.

Vigilância nutricional e morbidade de crianças menores de 5 anos numa unidade básica de saúde: análise da série histórica 1987-91

O presente estudo apresenta uma análise preliminar dos dados de estado nutricional (EN) e de morbidade de crianças menores de 5 anos, coletados pelo Sistema de Vigilância Alimentar e Nutricional (SISVAN) entre 1987 e 1991 numa unidade de atenção primária à saúde que atende a uma população favelada do Rio de Janeiro. Os perfis encontrados nas quase 35.000 consultas no período indicaram um importante desvio à esquerda, já no primeiro semestre de vida, para o indicador estatura/idade (E/I). Revelaram, ademais, que 20,4% das crianças apresentavam massa corporal para idade (MC/I) abaixo do percentil 10 da referência NCHS. Houve uma aparente tendência de diminuição da freqüência de crianças com nanismo (valor Z E/I < -2 Z) ao longo dos anos. Os oito motivos de consulta mais freqüentes foram os mesmos durante o período, mas suas freqüências variaram de ano para ano. Nos últimos 3 anos, os motivos mais freqüentes foram doenças do aparelho respiratório (AR), doenças do aparelho digestivo (AD) e desnutrição. Não se observou uma tendência clara entre freqüência de doenças do AR e EN, observando-se, no entanto, uma relação inversa entre a freqüência de AD e o percentil de MC/I. Além de indicarem um relevante quadro de déficit de crescimento da clientela estudada, justificando a implantação do SISVAN, estes resultados também reforçam a necessidade de outros estudos relacionando os perfis nutricional e de morbidade da clientela antendida em serviços de atenção primária, potencializando o papel do SISVAN na rede de saúde.