Objective To establish the incidence and aetiology of infectious intestinal disease in the community and presenting to general practitioners. Comparison with incidence and aetiology of cases reaching national laboratory based surveillance. Design Population based community cohort incidence study, general practice based incidence studies, and case linkage to national laboratory surveillance. Setting 70 general practices throughout England. Participants 459 975 patients served by the practices. Community surveillance of 9776 randomly selected patients.

Absence of prior M. tuberculosis infection or sensitization with environmental mycobacteria is associated with higher efficacy of BCG against pulmonary tuberculosis and possibly against miliary and meningeal tuberculosis. Evaluations of new tuberculosis vaccines should account for the possibility that prior infection may mask or block their effects.

ObjectivesTo estimate, overall and by organism, the incidence of infectious intestinal disease (IID) in the community, presenting to general practice (GP) and reported to national surveillance.DesignProspective, community cohort study and prospective study of GP presentation conducted between April 2008 and August 2009.SettingEighty-eight GPs across the UK recruited from the Medical Research Council General Practice Research Framework and the Primary Care Research Networks.Participants6836 participants registered with the 88 participating practices in the community study; 991 patients with UK-acquired IID presenting to one of 37 practices taking part in the GP presentation study.Main outcome measuresIID rates in the community, presenting to GP and reported to national surveillance, overall and by organism; annual IID cases and GP consultations by organism.ResultsThe overall rate of IID in the community was 274 cases per 1000 person-years (95% CI 254 to 296); the rate of GP consultations was 17.7 per 1000 person-years (95% CI 14.4 to 21.8). There were 147 community cases and 10 GP consultations for every case reported to national surveillance. Norovirus was the most common organism, with incidence rates of 47 community cases per 1000 person-years and 2.1 GP consultations per 1000 person-years. Campylobacter was the most common bacterial pathogen, with a rate of 9.3 cases per 1000 person-years in the community, and 1.3 GP consultations per 1000 person-years. We estimate that there are up to 17 million sporadic, community cases of IID and 1 million GP consultations annually in the UK. Of these, norovirus accounts for 3 million cases and 130 000 GP consultations, and Campylobacter is responsible for 500 000 cases and 80 000 GP consultations.ConclusionsIID poses a substantial community and healthcare burden in the UK. Control efforts must focus particularly on reducing the burden due to Campylobacter and enteric viruses.

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Objectives To determine whether BCG vaccination protects against Mycobacterium tuberculosis infection as assessed by interferon γ release assays (IGRA) in children.Design Systematic review and meta-analysis. Searches of electronic databases 1950 to November 2013, checking of reference lists, hand searching of journals, and contact with experts. Setting Community congregate settings and households.Inclusion criteria Vaccinated and unvaccinated children aged under 16 with known recent exposure to patients with pulmonary tuberculosis. Children were screened for infection with M tuberculosis with interferon γ release assays. Data extractionStudy results relating to diagnostic accuracy were extracted and risk estimates were combined with random effects meta-analysis. ResultsThe primary analysis included 14 studies and 3855 participants. The estimated overall risk ratio was 0.81 (95% confidence interval 0.71 to 0.92), indicating a protective efficacy of 19% against infection among vaccinated children after exposure compared with unvaccinated children. The observed protection was similar when estimated with the two types of interferon γ release assays (ELISpot or QuantiFERON). Restriction of the analysis to the six studies (n=1745) with information on progression to active tuberculosis at the time of screening showed protection against infection of 27% (risk ratio 0.73, 0.61 to 0.87) compared with 71% (0.29, 0.15 to 0.58) against active tuberculosis. Among those infected, protection against progression to disease was 58% (0.42, 0.23 to 0.77). Conclusions BCG protects against M tuberculosis infection as well as progression from infection to disease.Trial registration PROSPERO registration No CRD42011001698 (www. crd.york.ac.uk/prospero/). IntroductionBCG vaccine has been the subject of numerous efficacy trials and epidemiological studies conducted over several decades. These trials indicate that BCG has 60-80% protective efficacy against severe forms of tuberculosis in children, particularly meningitis, 1 2 and its efficacy against pulmonary diseases varies geographically.3-5 BCG does not seem to protect against disease when it is given to people already infected or sensitised to environmental mycobacteria, which could explain the geographical variation.6-8 Until recently it was not possible to establish whether the protective effect of BCG vaccination against disease was from its action in preventing acquisition of infection or limited to prevention of progression from infection to clinical disease.The scarcity of evidence on whether the vaccine is effective against Mycobacterium tuberculosis infection was because of limitations of the tuberculin skin test. This test cannot distinguish a positive response caused by M tuberculosis infection from that caused by BCG vaccination or non-tuberculous In this systematic review we examined the evidence for the protective effect of BCG against M tuberculosis infection, as opposed to against disease, in settings where children can be presumed to have been exposed to M tu...

Despite pronounced reductions in the number of deaths due to infectious diseases over the past six decades, infectious diseases are still a public health problem in Brazil. In this report, we discuss the major successes and failures in the control of infectious diseases in Brazil, and identify research needs and policies to further improve control or interrupt transmission. Control of diseases such as cholera, Chagas disease, and those preventable by vaccination has been successful through efficient public policies and concerted efforts from different levels of government and civil society. For these diseases, policies dealt with key determinants (eg, the quality of water and basic sanitation, vector control), provided access to preventive resources (such as vaccines), and successfully integrated health policies with broader social policies. Diseases for which control has failed (such as dengue fever and visceral leishmaniasis) are vector-borne diseases with changing epidemiological profiles and major difficulties in treatment (in the case of dengue fever, no treatment is available). Diseases for which control has been partly successful have complex transmission patterns related to adverse environmental, social, economic, or unknown determinants; are sometimes transmitted by insect vectors that are difficult to control; and are mostly chronic diseases with long infectious periods that require lengthy periods of treatment.

The protective effect of BCG against tuberculosis (TB) estimated in randomized controlled trials and observational studies ranges from negative to close to a 100%. One of the many explanations offered for this is that different immunological mechanisms may be associated with protective effect against different forms and sites of disease. In this investigation, we recalculated vaccine protective effect separately for pulmonary disease and for meningeal/miliary disease in randomized controlled trials and case-control studies, tested for heterogeneity in site-specific estimates of protective effect and calculated a summary measure when appropriate. We found protective effect against pulmonary disease to be heterogeneous to a statistically significant degree, and thus we did not calculate a summary measure of protection. Protective effect against meningeal and miliary TB was higher than against pulmonary disease and, except for a single study with two cases only, appeared to be homogenous. Summary BCG protective effect against miliary or meningeal TB in randomized controlled trials was 86% (95% confidence interval [CI] 65, 95) and in case-control studies 75% (95% CI: 61, 84). The fact that protective effect appeared to be homogeneous against meningitis and miliary TB but not against pulmonary disease may result from the fact that patients with meningitis are on average younger and thus less likely to have been exposed to atypical bacteria; to a waning of the protective effect of BCG; or from the diversity of mechanisms of pathogenesis of pulmonary disease, which can originate from reinfection, reactivation or primary progression.