We systematically reviewed the current understanding of human population immunity against SARS-CoV in different groups, settings and geography. Our meta-analysis, which included all identified studies except those on wild animal handlers, yielded an overall seroprevalence of 0·10% [95% confidence interval (CI) 0·02–0·18]. Health-care workers and others who had close contact with SARS patients had a slightly higher degree of seroconversion (0·23%, 95% CI 0·02–0·45) compared to healthy blood donors, others from the general community or non-SARS patients recruited from the health-care setting (0·16%, 95% CI 0–0·37). When analysed by the two broad classes of testing procedures, it is clear that serial confirmatory test protocols resulted in a much lower estimate (0·050%, 95% CI 0–0·15) than single test protocols (0·20%, 95% CI 0·06–0·34). Potential epidemiological and laboratory pitfalls are also discussed as they may give rise to false or inconsistent results in measuring the seroprevalence of IgG antibodies to SARS-CoV.

The study sought to identify factors involved in the emergence, prevention and elimination of severe acute respiratory syndrome (SARS) in Hong Kong during 11 March to 22 May 2003. A structured multiphase regression analysis was used to estimate the potential effects of weather, time and interaction effect of hospital infection. In days with a lower air temperature during the epidemic, the risk of increased daily incidence of SARS was 18·18-fold (95% confidence interval 5·6–58·8) higher than in days with a higher temperature. The total daily new cases might naturally decrease by an average of 2·8 patients for every 10 days during the epidemic. The multiplicative effect of infected hospital staff with patients in an intensive care unit (ICU) and the proportion of SARS patients in ICUs might respectively increase the risk of a larger SARS epidemic in the community. The provision of protective gear in hospitals was also a very important factor for the prevention of SARS infection. SARS transmission appeared to be dependent on seasonal temperature changes and the multiplicative effect of hospital infection. SARS also appeared to retreat naturally over time.

A vaccination programme offering hepatitis B (HBV) vaccine at reception into prison has been introduced into selected prisons in England and Wales. Over the coming years it is anticipated this vaccination programme will be extended. A model has been developed to assess the potential impact of the programme on the vaccination coverage of prisoners, ex-prisoners, and injecting drug users (IDUs). Under a range of coverage scenarios, the model predicts the change over time in the vaccination status of new entrants to prison, current prisoners and IDUs in the community. The model predicts that at baseline in 2012 57% of the IDU population will be vaccinated with up to 72% being vaccinated depending on the vaccination scenario implemented. These results are sensitive to the size of the IDU population in England and Wales and the average time served by an IDU during each prison visit. IDUs that do not receive HBV vaccine in the community are at increased risk from HBV infection. The HBV vaccination programme in prisons is an effective way of vaccinating this hard-to-reach population although vaccination coverage on prison reception must be increased to achieve this.

More people with hepatitis C virus pass through incarcerated settings each year than any other venue. The goal of this study was to assess inmates' attitudes towards hepatitis C testing and treatment while incarcerated. We interviewed 153 male and female inmates at the Rhode Island Department of Corrections (RIDOC). Ninety-one per cent of inmates said they would agree to be tested for hepatitis C and 95% said that they would be willing to be treated for hepatitis C while incarcerated. Thirty-three per cent perceived themselves to be at risk for hepatitis C. Inmates were very interested in hepatitis C testing and, if indicated treatment. Inmates' attitudes towards hepatitis C testing and treatment do not pose a major obstacle to implementing comprehensive hepatitis C screening and treatment programme in correctional settings.

This study analyses a screening programme for hepatitis C virus (HCV) infection among US veterans in a suburban Veterans Affairs Medical Center, in New York. This is the first study examining all 11 potential risk factors listed in the 2001 National U.S. Veterans Health Administration Screening Guidelines. A retrospective study was conducted of 5400 veterans ‘at risk’ of HCV, identified through a questionnaire in this institution's primary-care outpatient departments between 1 October 2001 and 31 December 2003. Multivariate logistic regression models were built to identify independent predictors of infection. Of 2282 veterans tested for HCV, 4·6% were confirmed by HCV PCR to be HCV infected. In the multivariate model developed, injection drug use, blood transfusion before 1992, service during the Vietnam era, tattoo, and a history of abnormal liver function tests were independent predictors of HCV infection. Our data support considering a more targeted screening approach that includes five of the 11 risk factors.

In February and in June 1998, two people developed acute hepatitis B following in-patient care in a district general hospital. Initial enquiries indicated their infections were not attributable to staff undertaking exposure-prone procedures (EPPs). We report the findings and implications of the subsequent investigation: a multi-disciplinary, multi-agency investigation, including molecular epidemiological analysis. Occupational Health records showed that staff involved in EPPs with the patients were HBsAg negative. No contact between the patients was identified nor were there failures in sterilization. The patients' HBV strains were identical, indicating a common source. A total of 231 out of 232 staff who might have treated either patient were tested for HBsAg; the remaining doctor, working abroad, was HBsAg- and HBeAg-positive and had the same HBV strain as the patients. On two occasions the doctor's hand had been cut while breaking glass vials, but there was no documentation linking these events to the two patients. The doctor had been vaccinated in 1993 and tested for anti-HBs prior to commencing work in 1997. The doctor was recalled to Occupational Health but did not attend and was not followed up. In total, 4948 patients potentially treated by the doctor received an explanatory letter and 3150 were tested for HBsAg. Only one was positive, and HBV sequencing showed no link to the doctor. Occasionally transmission of HBV from heath-care workers can occur in a non-EPP setting and the implications of this require examination by those setting national policy. Occupational Health Services should investigate clinical heath-care workers who do not respond to vaccination. They should ensure HBV carriers are identified and offer them appropriate advice to prevent transmission to patients.

Twenty-one Candida albicans isolates from three HIV-infected patients were collected over a period of 3 years and characterized for fluconazole susceptibility, infectivity and genetic relatedness. Fluconazole resistance was found in five isolates, four exhibited dose-dependent susceptibility and the remainder were fully susceptible to this agent. Pulsed-field gel electrophoresis of SfiI restriction digests of the genomic DNA from the isolates revealed that isolates from the same swab specimen were identical despite differences in susceptibility to fluconazole and isolates recovered over time from the three patients retained clonally related DNA fingerprints within each patient. This small-scale study confirms the persistence of oral colonization of C. albicans strains in HIV-infected patients. Clinical data also suggests that the primary infecting strain may become a persistent colonist in the oral cavity once the immune function of the patient has been restored.

The lymphocyte profile of 521 HIV-infected subjects hospitalized at Jackson Memorial (2001–2002) was compared across main respiratory diseases. Study data included medical history and all laboratory evaluations performed during hospitalization. Community-acquired pneumonias (CAP, 52%), Pneumocystis jiroveci pneumonia (PCP, 24%), tuberculosis (TB, 9%) and non-tuberculous mycobacterial diseases (NTM, 12%) were the most frequent causes of admission. Patients hospitalized with PCP and NTM exhibited the lowest CD4 counts (P=0·003). PCP patients had the highest B-cell percentages (P=0·04). CAP patients had the highest CD8 and CD4 percentages and the lowest percentage of Natural Killer (NK) cells and viral burdens. TB patients exhibited the lowest NK-cell (11·4±6·3) and B-cell percentages (13·6±12) and the highest CD8 (59±14) percentage. NTM patients, in contrast, had the highest NK-cell percentages of the groups (19·1±11·6, P=0·01). Additionally, immune responses associated with respiratory pathogens differed in HIV-infected patients with CD4+ cells above and below 200 counts.

A number of outbreaks and pseudo-outbreaks have been associated with contaminated rinse water in endoscope washer-disinfectors. Health Technical Memorandum 2030 specifies that final rinse water should be ‘bacteria-free’. In this study, results of rinse-water testing from 20 endoscopy units were reviewed over a 4-month period. Over 60% of samples were of an unsatisfactory quality (i.e. not bacteria-free) and none of the endoscopy units consistently achieved sterile water throughout the study period. Poor microbiology results caused anxiety to endoscopy staff and infection control teams who had to decide whether or not to take washer-disinfectors out of use, possibly resulting in delays to medical procedures. There was no common policy on how to react to poor results, with staff at each unit developing their own action levels. Here, it is suggested that future guidelines would be of more practical use if they specified a series of action levels of increasing severity based on the bacterial count in a water sample.

We conducted a prospective, cohort study at two affiliated level III neonatal intensive care units to evaluate the effect of a closed drug-delivery system on the incidence of nosocomial and catheter-related bloodstream infections (CRBSI) in infants. A total of 300 infants (n=150 at each site) were enrolled over a 4-year study period. There was no difference in the rate of CRBSI per 1000 catheter days between the two sites (16·2±39 vs. 8·9±24, P=0·054, 95% CI−14·8 to 0·13). Infants at site A (closed drug-delivery system) had a higher rate of infectious nosocomial respiratory complications per 100 hospital days than infants at site B (open delivery system) (1·1±2·2 vs. 0·5±1·5, P=0·009), however, there was no difference in the overall number of confirmed or suspected nosocomial infection events per patient between study sites. Logistic regression revealed that the number of additional peripheral catheters, gestational age and duration of parenteral nutrition all significantly contributed to the risk of developing one or more CRSBI. The closed drug-delivery system failed to reduce the incidence of CRBSI or overall rate of nosocomial infections in premature infants.

A population-based insurance claims database was used to examine cellulitis incidence, anatomical sites of infection, complicating diagnoses, source of health service, and recurrence rates. Insurance claim files were searched for cellulitis ICD-9-CM codes 681.0–682.9. Complications of cellulitis including erysipelas, lymphadenitis, lymphangitis, and necrotizing fasciitis were also identified by ICD-9-CM codes. We found a cellulitis incidence rate of 24·6/1000 person-years, with a higher incidence among males and individuals aged 45–64 years. The most common site of infection was the lower extremity (39·9%). The majority of patients were seen in an outpatient setting (73·8%), and most (82·0%) had only one episode of cellulitis during the 5-year period studied. There was a very low incidence of cellulitis complications, including necrotizing fasciitis. Cellulitis is fairly common, usually treated in outpatient settings, and is infrequently complicated by erysipelas, lymphadenitis, lymphangitis, or necrotizing fasciitis.

The study was undertaken in response to local concerns of a rising number of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) infections. All patients resident in the community in Essex at the time of diagnosis with a first isolate of MRSA between 1994 and 2001 identified by the diagnostic microbiology laboratory were included. Although the annual incidence rose throughout the study period the majority of those with MRSA (82%) had had hospital contact within the last 5 years. The subset of patients without hospital contact had a median age of 79·5 years, 63% were female and 32% were residents of care homes. Carriage in this population was detected for up to 41 months post-diagnosis. Neither antibiogram nor clinical presentation distinguished these isolates from local hospital-acquired strains.

We analysed data from 33741 patients with ICD-10-AM-defined sepsis from an Australian hospital morbidity dataset to investigate the relationships between specific types of organisms, potential risk factors for infection, organ dysfunction, ICU utilization and hospital mortality. A total of 24% of patients received some of their care in an intensive care unit, and the overall hospital mortality rate was 18%. Gram-positive bacteria were isolated in 27% of cases and Gram-negative bacteria in 20%. Sepsis due to Staphylococcus aureus was associated with vascular and joint devices whereas Pseudomonasaeruginosa and Gram-negative rods were more common with genitourinary devices and lymphoproliferative disease. Sepsis-associated organ dysfunction most commonly involved the respiratory system, followed by the renal and circulatory systems. These patterns may provide useful clues to the pathogenesis and therapy of this often fatal syndrome which is a major ongoing problem for hospitalized patients.

Sepsis continues to have a substantial mortality and morbidity despite advances in the diagnosis and management of this condition. We retrospectively analysed hospital charts of patients diagnosed to have sepsis between January 2002 and June 2003. Demographic characteristics of patients, microbiological findings and predictors of survival were evaluated. Sixty-nine sepsis episodes that occurred in 63 patients were analysed. The most common underlying diseases were hypertension, malignancies and diabetes mellitus. Renal insufficiency, respiratory distress and disseminated intravascular coagulation developed in 52·2, 30·4 and 30·4% of the episodes respectively; 47·7% of the blood cultures yielded an organism. Gram-negative bacteria were the predominant microorganisms (65·9%). Fifty-five patients (87·3%) died. Mechanical ventilation and underlying renal disease were significant determinants of mortality. In conclusion, Gram-negative bacteria remain the major pathogens in sepsis. The mortality remains very high, and a change in the clinical approach to the septic patient should be employed to improve the outcome.

A cluster of 10 cases of tuberculosis disease (one of them extrapulmonary) occurred from July 2001 until November 2003 in a health district in Southern Austria. Eight patients were culture confirmed and shared an identical strain. One of these eight cases was identified as outbreak-related by molecular strain typing only. Due to public pressure, a further 600 persons received chest X-ray and clinical examinations. Apart from one case which could be excluded from the outbreak because of a different strain pattern, no outbreak-related case of active tuberculosis was detected by this non-targeted procedure. Tuberculin skin testing, not part of the Austrian routine protocol of contact investigation in adults, was initiated after diagnosis of case 8. Forty-nine latently infected contacts were detected. Population-based genotyping of all isolates, prioritization of contact investigations and early use of targeted tuberculin skin testing are critical for effective tuberculosis control in low-incidence countries.

The relationship of Mycobacterium tuberculosis Beijing genotype with tuberculosis relapse was examined. Beijing strains were detected from 32 out of 45 (71%) relapsed cases and 148 out of 290 (51%) non-relapsed cases. Multivariate logistic regression analysis revealed that Beijing genotype was significantly associated with tuberculosis relapse (OR 2·64, 95% CI 1·30–5·34, P=0·005).

To date there has been no satisfactory explanation of the worldwide excess of tuberculosis (TB) notifications among adult males. We investigated the epidemiological basis for sex differences in TB notifications in high-burden countries using available group-level data. Multiple linear regression analysis was used to explore the ecological relationship between smoking and sex differences in TB notifications among high-burden countries. Cigarette consumption was a significant predictor of the sex ratio of TB notifications, and explained 33% of the variance in the sex ratio of TB notifications. Our findings suggest that smoking is an important modifiable factor which has a significant impact on the global epidemiology of TB, and emphasize the importance of tobacco control in countries with a high incidence of TB. This analysis provides support for the interpretation of sex differences in worldwide TB notification rates as indicative of true differences in the epidemiology of TB between males and females.

Mucormycosis is a fairly rare fungal infection caused by ubiquitous fungi of the order Mucorales and primarily affects immunocompromised hosts. A series of 16 cases of invasive mucormycosis admitted to three referral centres in Beirut, Lebanon between 1981 and 1999 is described. It includes 12 patients with rhinocerebral, three with cutaneous, and one with pulmonary infection. Onset of symptoms occurred in the summer and autumn in 15 out of 16 patients, showing a statistically significant seasonal variation (P=0·007) A recent report of 19 patients from Tel Aviv describes a strikingly similar seasonal pattern. Studies on atmospheric concentration of Mucorales spores in the Eastern Mediterranean are lacking. Weather pattern analysis in Beirut revealed clustering of onset of invasive mucormycosis at the end of a dry, warm period, which begins around May and ends in October. Mucormycosis incidence appears to be seasonal in the Eastern Mediterranean.

False-positive serological reactions (FPSR) due to infections with Yersinia enterocolitica serotype O[ratio ]9 (YeO[ratio ]9) are a problem in tests for brucellosis. In the present study, FPSR in classical and novel tests for brucellosis following experimental infections of pigs with YeO[ratio ]9 were compared with responses of B. suis biovar 2-inoculated pigs. FPSR were limited to 2–9 weeks post-YeO[ratio ]9 inoculation, while B. suis-infected pigs were test-positive throughout the 21-week period of investigation. Although YeO[ratio ]9-inoculated pigs exhibited FPSR in Brucella tests for a limited period of time, the serological responses in a YeO[ratio ]9-purified O-antigen indirect ELISA did not decrease accordingly. Analysis of available cross-sectional serum samples from pig herds naturally infected with YeO[ratio ]9 or B. suis biovar 2 confirmed that the observed difference in the duration of the serological responses between the two infections could be used to discriminate between herds infected with B. suis biovar 2 and YeO[ratio ]9.

In recent years, the control or eradication of scrapie and any other transmissible spongiform encephalopathies (TSEs) possibly circulating in the sheep population has become a priority in Britain and elsewhere in Europe. A better understanding of the epidemiology of scrapie would greatly aid the development and evaluation of control and eradication strategies. Here we bound the range of key epidemiological parameters using a combination of relatively detailed pathogenesis and demography data, more limited data on susceptibility and incubation times, and recent survey data on scrapie incidence in Great Britain. These data are simultaneously analysed using mathematical models describing scrapie transmission between sheep and between flocks. Our analysis suggests that occurrence of scrapie in a flock typically provokes changes in flock management that promote termination of the outbreak, such as the adoption of selective breeding, and that a large fraction of cases (possibly over 80%) goes undetected. We show that the data analysed are consistent with the within-flock reproduction number of scrapie lying in the range 1·5–6, consistent with previous epidemiological studies.