Passive detection of tuberculosis (TB) cases may lead to delay in treatment which may contribute to increased severity of disease and mortality. Active case finding may be an alternative. In a community survey in Cape Town, South Africa, we actively detected 27 bacteriologically positive TB cases and compared those with 473 passively detected TB cases. Seven of 27 (26%) actively detected TB cases did not start treatment within 2 months and were considered initial defaulters. Those who did start treatment had similar treatment success rates as passively detected TB cases (both 80%) (OR 1·01, 95% CI 0·33–3·09). Passively detected cases reported the presence of the symptoms cough (OR 3·72, 95% CI 1·47–9·39), haemoptysis (OR 3·20, 95% CI 1·03–9·93), night sweats (OR 3·35, 95% CI 1·40–7·99), fever (OR 4·28, 95% CI 1·21–15·14), and weight loss (OR 11·14, 95% CI 4·17–29·74) more often than those detected actively. We conclude that although TB cases detected by a community survey are less symptomatic and are prone to a high initial default rate, active case finding can potentially identify a substantial portion of the existing caseload at an earlier stage of disease, thereby reducing the risk of transmission.

Vertebral osteomyelitis (VO) is a rare event. To estimate the incidence of VO in France for 2002–2003, national hospital-discharge data were used. Hospital stays were categorized as definite, probable or possible VO. Unique patient identification numbers allowed the investigators to link patients with multiple hospital stays and to analyse data for individual patients. A sample of medical records was reviewed to assess the specificity of the VO case definition. In 2002–2003, 1977 and 2036 hospital stays corresponding to 1422 and 1425 patients (median age 59 years, male:female ratio 1·5) were classified as definite (64%), probable (24%) and possible (12%) VO. The overall incidence of VO was 2·4/100 000. Incidence increased with age: 0·3/100 000 (<20 years), 3·5/100 000 (50–70 years) and 6·5/100 000 (>70 years). The main infectious agents reported were Staphylococcus spp. (38%) and Mycobacterium tuberculosis (31%). The most frequent comorbidities were septicaemia (27%) and endocarditis (9%). Three percent of patients died. A review of 90 medical records confirmed the diagnosis of VO in 94% of cases. Using a hospital database and a specific case definition, nationwide surveillance of VO is possible.

This study evaluated the first use of a combination of the lyophilized components of the conjugated group C vaccine Menjugate™ reconstituted with the liquid group B outer membrane vesicle (OMV) vaccine MeNZB™. At 6-week intervals, healthy residential students received three doses of MeNZB alone or concomitantly with one dose of Menjugate (MeNZB+MenC). Short-lasting injection-site reactions of mild or moderate intensity were frequent in both groups. There were no vaccine-related serious adverse events. After three doses, the percentage of subjects with serum bactericidal assay (SBA) titres ⩾1:8 against the serogroup B strain NZ98/254 was 82% for MeNZB+MenC and 78% for MeNZB. All subjects in the MeNZB+MenC group achieved SBA titres ⩾1:8 against serogroup strain C11 and 67% in the MeNZB group. All SBA and ELISA responses of the combined vaccine were at least as good as for MeNZB alone. After vaccination, the pharyngeal carriage rate of any meningococcus in the vaccinated group had declined from 40% to 21%.

Sexual dimorphism in infectious diseases whereby disease incidence is more prevalent in one gender has been reported repeatedly in the scientific literature. Both behavioural and physiological differences have been suggested as a cause of this gender bias but there is a paucity of data to support either of these viewpoints. Here it is hypothesized that for campylobacteriosis physiological factors play an important role in the higher incidence in males. We demonstrate in the human population (from several countries in three continents) that this bias exists in young children (<1 year) where behavioural differences between genders are likely to be minimal. Further we demonstrate this difference in an animal model where both infection rates and shedding rates of the organism are greater in male mice.

Using multivariable models, we compared whether there were significant differences between reported outbreak and sporadic cases in terms of their sex, age, and mode and site of disease transmission. We also determined the potential role of administrative, temporal, and spatial factors within these models. We compared a variety of approaches to account for clustering of cases in outbreaks including weighted logistic regression, random effects models, general estimating equations, robust variance estimates, and the random selection of one case from each outbreak. Age and mode of transmission were the only epidemiologically and statistically significant covariates in our final models using the above approaches. Weighing observations in a logistic regression model by the inverse of their outbreak size appeared to be a relatively robust and valid means for modelling these data. Some analytical techniques, designed to account for clustering, had difficulty converging or producing realistic measures of association.

The Randomized Badger Culling Trial (RBCT) began in 1998 to determine the impact of badger culling in controlling bovine tuberculosis in cattle. A total of 1166 badgers (14% of total) proactively culled during the RBCT were found to be tuberculous, offering a unique opportunity to study the pathology caused by Mycobacterium bovis in a large sample of badgers. Of these, 39% of adults (~6% of all adults culled) had visible lesions (detectable at necropsy) of bovine tuberculosis; cubs had a lower prevalence of infection (9%) but a higher percentage of tuberculous cubs (55·5%) had visible lesions. Only ~1% of adult badgers had extensive, severe pathology. Tuberculous badgers with recorded bite wounds (~5%) had a higher prevalence of visible lesions and a different distribution of lesions, suggesting transmission via bite wounds. However, the predominance of lesions in the respiratory tract indicates that most transmission occurs by the respiratory route.

A rise in invasive Haemophilus influenzae type b (Hib) infections occurred 8 years after vaccine introduction in the United Kingdom. Aspects of Hib vaccine delivery unique to the United Kingdom have been implicated. The authors developed a fully age-structured deterministic susceptible–infected–resistant–susceptible mathematical model, expressed as a set of partial differential equations, to better understand the causes of declining vaccine effectiveness. We also investigated the consequences of the vaccine's impact on reducing Hib transmission for maintenance of immunity. Our findings emphasized the importance of maintaining high post-immunization antibody titres among age groups at greatest risk of invasive infections. In keeping with UK population-based estimates, low direct efficacy of immunological memory against disease was found, cautioning against over-reliance on evidence of priming alone as a correlate of population protection. The contribution of herd immunity to disease control was reinforced. Possible intervention strategies will be explored in subsequent work.

During 2003, a cluster of initially unexplained pneumonia cases (two fatal) occurred in patients aged <50 years in a British city. Routine culture tests were inconclusive, however, pneumococcal infection was suspected and the putative outbreak was investigated using non-culture methods. Clinical samples from ten patients were tested by pneumococcal polymerase chain reaction (PCR) and multi-locus sequence typing (MLST), or Binax NOW® pneumococcal urine antigen test and serotype-specific enzyme-linked immunosorbent assay (ELISA). Lung samples from the deceased patients were PCR positive and yielded different MLST types. Two patients in one family group were serotype 1 pneumococcal antigen positive. Two further patients were serotype 1 antigen positive, and one serotype 4 positive. Two antigen-positive cases were also serum PCR positive. Non-culture methods confirmed the disease aetiology in six cases. Serotype and MLST results showed no single outbreak, but a family cluster of cases in a high background of pneumococcal pneumonia, providing important epidemiological data that would not otherwise have been available.

Improving the efficiency of outbreak investigation in restaurants is critical to reducing outbreak-associated illness and improving prevention strategies. Because clinical characteristics of outbreaks are usually available before results of laboratory testing, we examined their use for determining contributing factors in outbreaks caused by restaurants. All confirmed foodborne outbreaks reported to the Centers for Disease Control and Prevention (CDC) from 1982 to 1997 were reviewed. Clinical profiles were developed based on outbreak characteristics. We compared the percentage of contributing factors by known agent and clinical profile to their occurrence in outbreaks of unclassified aetiology. In total, 2246 foodborne outbreaks were included: 697 (31%) with known aetiology and 1549 (69%) with aetiology undetermined. Salmonella accounted for 65% of outbreaks with a known aetiology. Norovirus-like clinical profiles were noted in 54% of outbreaks with undetermined aetiology. Improper holding times and temperatures were associated with outbreaks caused by Clostridium perfringens, Bacillus cereus, Staphylococcus aureus, and Salmonella, and also with outbreaks of undetermined aetiology that fitted diarrhoea-toxin and vomiting-toxin clinical profiles. Poor personal hygiene was associated with norovirus, Shigella, and Salmonella, and also with outbreaks that fitted norovirus-like and vomiting-toxin clinical profiles. Contributing factors were similar for outbreaks with known aetiology and for those where aetiology was assigned by corresponding clinical profile. Rapidly categorizing outbreaks by clinical profile, before results of laboratory testing are available, can help identification of factors which contributed to the occurrence of the outbreak and will promote timely and efficient outbreak investigations.

The aim of the study was to estimate the prevalence and risk factors associated with infection by high-risk human papillomavirus (HR-HPV) in cervix and squamous intra-epithelial lesions (SIL) in imprisoned women. This was done by a cross-sectional study of imprisoned women attending the gynaecological clinic in Foncalent prison in Alicante, Spain. The study period was from May 2003 to December 2005. HR-HPV infection was determined through Digene HPV Test, Hybrid Capture II (HC-II). HPV typing was determined by multiplex nested PCR assay combining degenerate E6/E7 consensus primers. Multiple logistic regression modelling was used for the analysis of associations between variables where some were considered possible confounders after checking for interactions. A total of 219 women were studied. HR-HPV prevalence was 27·4% and prevalence of SIL was 13·3%. HIV prevalence was 18%, higher in Spaniards than in migrant women (24·6% vs. 14·3%, P<0·05). In multivariate analyses, risk factors for HPV infection were younger age (P for trend=0·001) and tobacco use (OR 2·62, 95% CI 1·01–6·73). HPV infection (OR 4·8, 95% CI 1·7–13·8) and HIV infection were associated with SIL (OR 4·8, 95% CI 1·6–14·1). The commonest HPV types were HPV16 (29·4%), HPV18 (17·6%), HPV39 (17·6%) and HPV68 (17·6%). The prevalence of both HR-HPV infection and SIL in imprisoned women found in this study is high. Determinants for each of the outcomes studied were different. HPV infection is the most important determinant for SIL. A strong effect of HIV co-infection on the prevalence of SIL has been detected. Our findings reinforce the need to support gynaecological clinics in the prison setting.

The UK has had a pneumococcal polysaccharide vaccination (PPV) programme for groups at higher risk of invasive disease since 1992. This paper presents data from a sample of primary-care practices (Q-RESEARCH) of PPV uptake in patients according to their risk status. Of 2·9 million registered patients in 2005, 2·1% were vaccinated with PPV in the preceding 12 months and 6·5% in the preceding 5 years. Twenty-nine per cent of the registered population fell into one or more risk groups. The proportion of each risk group vaccinated in the previous 5 years ranged from 69% (cochlear implants), 53·4% (splenic dysfunction), 36·5% (chronic heart disease), 34·7% (diabetes), 22·9% (immunosuppressed), 28·7% (chronic renal disease), 15·9% (sickle cell disease) to 12·6% (chronic respiratory disease). Uptake was lower in areas where the non-white proportion of population was >10%. In conclusion, there remain large gaps in the uptake of PPV in several high-risk populations in the United Kingdom. Effective strategies need to be developed to address these deficiencies.

In this study, we have analysed the epidemiological significance of the concurrent infections caused by Vibrio cholerae and intestinal parasites among different age groups of hospitalized diarrhoeal patients in Kolkata. A total of 3556 stool samples collected during 1996–2004 were screened for vibrios and parasites. The seasonality of V. cholerae and parasitic infections were studied in detail. The detection rates for Ascaris lumbricoides and Giardia lamblia infection were more than for the hookworm, Trichuris trichiura and Entamoeba histolytica. V. cholerae O1 was identified as the predominant serogroup among diarrhoeal patients. The highest rates for V. cholerae infection were in the 2–5 years age group and combined infection of V. cholerae and parasites was recorded among children aged between 2 and 10 years.

Since 2001 hepatitis B vaccination has been offered to prisoners on reception into prisons in England and Wales. However, short campaigns of vaccinating the entire population of individual prisons have achieved high vaccination coverage for limited periods, suggesting that short campaigns may be a preferable way of vaccinating prisoners. A model is used that describes the flow of prisoners through prisons stratified by injecting status to compare a range of vaccination scenarios that describe vaccination on prison reception or via regular short campaigns. Model results suggest that vaccinating on prison reception can capture a greater proportion of the injecting drug user (IDU) population than the comparable campaign scenarios (63% vs. 55·6% respectively). Vaccination on prison reception is also more efficient at capturing IDUs for vaccination than vaccination via a campaign, although vaccination via campaigns may have a role with some infections for overall control.

The purpose of this study was to assess the association between human T-lymphotropic virus 1 (HTLV-1) and a lifetime history of active tuberculosis (TB) among relatives of HTLV-1-infected patients. We reviewed clinical charts of all relatives of HTLV-1-infected index cases who attended our institute in Lima from 1990–2004. The data of 1233 relatives was analysed; 394 (32·0%) were HTLV-1 positive. Eighty-one subjects (6·6%) had a history of active TB, including 45/394 (11·4%) HTLV-1-positive and 36/839 (4·3%) HTLV-1-negative relatives (P<0·001). On multivariate analysis, three factors were associated with TB history: HTLV-1 infection (adjusted OR 2·5, 95% CI 1·6–3·9), age (adjusted OR 1·3, 95% CI 1·1–1·5 per 10-year age increase) and relation to the index case (adjusted OR 2·6, 95% CI 1·3–5·1, for siblings vs. spouses of index cases). In conclusion, HTLV-1 infection may increase the susceptibility to active TB. In populations where both infections are frequent, such an association could affect the dynamics of TB.

The objective of this study was to address the impact of heterogeneity of infectious period and contagiousness on Salmonella transmission dynamics in dairy cattle populations. We developed three deterministic SIR-type models with two basic infected stages (clinically and subclinically infected). In addition, model 2 included long-term shedders, which were defined as individuals with low contagiousness but long infectious period, and model 3 included super-shedders (individuals with high contagiousness and long infectious period). The simulated dynamics, basic reproduction number (R0) and critical vaccination threshold were studied. Clinically infected individuals were the main force of infection transmission for models 1 and 2. Long-term shedders had a small impact on the transmission of the infection and on the estimated vaccination thresholds. The presence of super-shedders increases R0 and decreases the effectiveness of population-wise strategies to reduce infection, making necessary the application of strategies that target this specific group.

We report on the first recorded outbreak of cholera in Namibia. From December 2006 to February 2007, more than 250 cases of cholera were reported from the Omusati and Kunene provinces of Namibia. However, only nine bacterial isolates were obtainable for analysis. Isolates were all identified as Vibrio cholerae O1 serotype Inaba biotype El Tor. All isolates were susceptible to ampicillin, augmentin, chloramphenicol, nalidixic acid, ciprofloxacin, tetracycline, kanamycin, imipenem, ceftriaxone and ceftazidime; and they all showed resistance to trimethoprim, sulfamethoxazole and streptomycin. Pulsed-field gel electrophoresis analysis of bacteria incorporating either SfiI or NotI digestion revealed an identical fingerprint pattern for all isolates. These data together with results indicating identical antimicrobial susceptibility profiles for all isolates determined that the outbreak was caused by a single strain of V. cholerae.

An observational study was carried out, using data collected from four areas in the Irish midlands, between 1989 and 2004, to critically evaluate the long-term effects of proactive badger culling and to provide insights into reactive badger culling tuberculosis (TB) prevalence in cattle. Confirmed cattle herd TB incidence is the outcome measure used throughout. Relative to reactive culling, proactive badger culling was associated with a decrease in incidence in each of the 16 years of observation, which encompassed periods of both intensive and less-intensive badger removal. By 2004, we observed a decrease of 22% [95% confidence interval (CI) 15–29, P<0·001] in the entire proactive and 37% (95% CI 25–47, P<0·001), in the inner proactive removal areas. The size of the decrease increased with time (P=0·055). There was a decrease (constant over time) of at least 14% (95% CI 76–97, P=0·013) in incidence in the inner compared to the outer control area (herds ⩽2 km, >2 km, from proactive removal area boundaries, respectively). Incidence in the outer proactive removal area (herds <1·6 km from the proactive removal boundary) was similar to the inner control area (P=0·890). Incidence in the outer control area and total control area, compared to a neighbouring area some distance away, increased over the course of the study. Differences with the total control area were not statistically significant but the outer control area was 11% higher than the neighbouring area by 2004 (borderline significance P=0·057).

To determine if a prediction of epidemic cholera using climate data can be made, we performed autoregression analysis using the data recorded in Dhaka City, Bangladesh over a 20-year period (1983–2002) comparing the number of children aged <10 years who were infected with Vibrio cholerae O1 to the maximum and minimum temperatures and rainfall. We formulated a simple autoregression model that predicts the monthly number of patients using earlier climate variables. The monthly number of patients predicted by this model agreed well with the actual monthly number of patients where the Pearson's correlation coefficient was 0·95. Arbitrarily defined, 39·4% of the predicted numbers during the study period were within 0·8–1·2 times the observed numbers. This prediction model uses the climate data recorded 2–4 months before. Therefore, our approach may be a good basis for establishing a practical early warning system for epidemic cholera.

In June 2005 Coxiella burnetii-infected sheep, grazing and lambing on a meadow bordering a residential area, caused a large Q fever outbreak (331 cases) in Germany. Our outbreak investigation provided attack rates (AR) by distance between residence and meadow, sex and age groups. The AR of people living within 50 m of the meadow was 11·8%. It decreased the further the residence was from the meadow, falling to 1·3% at 350–400 m distance (RR 8·7, 95% CI 4·5–17·1). The AR was higher in men (RR 1·4, 95% CI 1·1–1·8). In the 25–64 years age group, the AR was 2·3 times higher compared to other age groups (95% CI 1·7–3·0). The distance-related AR showed a relationship between risk of infection and living close to the meadow. Ongoing urbanization will probably lead to further Q fever outbreaks, hence prevention activities undertaken by animal and public health practitioners should be aligned and strengthened.

Empirical data about contact frequencies of children is needed for estimating parameters in mathematical modelling studies that investigate the effect of targeting influenza intervention to children. A survey about the social contacts of school children was conducted in a primary school in Germany. The distribution of the daily numbers of contacts was stratified by age of the contacted person and by weekday. A negative binomial regression analysis was performed to investigate factors that influence contact behaviour. Using logistic regression analysis we examined the relationship between the numbers of private contacts and having been ill in the last 6 months. We computed effective contact numbers to take the heterogeneity in contact behaviour into account in assessing the contribution of children's contacts to the overall transmission of an infection. The possible effects of intervention measures such as school closure and vaccination on the transmission of respiratory-spread agents to other age groups are discussed.