Between April and September 2000, 60 injecting drug users in Scotland died or were hospitalized with severe illness. Laboratory investigations suggested that Clostridium novyi and other bacteria were important aetiological agents. To determine associated environmental/behavioural factors a case-control study was undertaken with 19 ‘definite’ and 32 ‘probable’ cases in Glasgow, Scotland. For every deceased case (n=19), up to three proxy individuals were interviewed. Three controls were identified for each case. Multivariate logistic regression analyses compared (i) all cases and controls; (ii) definite cases and matched controls; (iii) probable cases and matched controls. In all three analyses injecting into muscle or skin and injecting most of the time with a filter used by someone else were the variables most strongly associated with illness. Comparing only muscle-injecting cases and controls, cases were significantly more likely to have injected larger amounts of heroin per average injection than were controls. The findings make an important epidemiological contribution to the understanding of the public health and clinical implications of the contamination of illicit drugs by histotoxic clostridia.

The Danish meningococcal disease laboratory surveillance system was established in 1974, based on close collaboration between local Departments of Clinical Microbiology and the Reference Laboratory at Statens Serum Institut. The completeness of the clinical notification system integrated with the laboratory surveillance system has been estimated to be more than 95%. Overall 4257 (79%) of 5356 cases of meningococcal disease notified during 1974–1999 were confirmed by culture of Neisseria meningitidis. The proportion of culture-confirmed cases ranged from 70% in 1989 to 89% in 1980. Only 26 patients (0·6%) with culture-confirmed meningococcal disease were not notified. Serological phenotype and susceptibility to penicillin and sulphonamide were determined for all isolates. Multilocus enzyme electrophoresis and/or DNA-based analyses were used for the assessment of clusters and outbreaks. Meningococcal antibody tests and counter-immunoelectrophoresis were used for the ascertainment of suspected cases. These combined systems allowed timely and reliable management of outbreaks and identification of clusters.

Based on 92537 blood samples received from 7365 patients with a request for a meningococcal antibody test (MAT) during a 10-year period (1986–1995), the usefulness of the test in the diagnosis of meningococcal disease was assessed. Of 635 patients with culture-confirmed meningococcal disease, 88% were seronegative on admittance to hospital and 90% were seropositive 10–15 days after onset of disease. The humoral immune response in children <2 years of age was weaker than in older children and adults. Among 893 MAT-positive patients without culture-confirmed meningococcal disease, 261 (29%) had been notified as cases of meningococcal disease. Among 228 patients notified as serologically confirmed the MAT results were consistent with the clinical diagnosis in 86%. MAT is a reliable tool for establishing a diagnosis in patients with suspected meningococcal disease. Key factors facilitating appropriate interpretation of negative as well as positive test results were: time(s) of sampling(s) after onset of disease, age of the patient and clinical features.

Culture for Bordetella pertussis (B. pertussis) is the traditional gold standard for laboratory diagnosis of pertussis but is insensitive, especially later in the course of illness and in vaccinated persons. Interpretation of serology is limited by the lack of an appropriate reference standard. An outbreak of pertussis in a crowded boarding-school dormitory allowed evaluation of laboratory correlates of infection. Questionnaires, serum samples and throat swabs were collected from members of the exposed group. Serum samples from unexposed controls of a similar age group were used for comparison. B. pertussis PCR was performed on throat swabs, and sera were tested for IgA antibodies against whole-cell (WC) B. pertussis antigen and IgG antibodies to pertussis toxin (PT). The Centers for Disease Control and Prevention definition for pertussis was used to define clinical cases. We evaluated the use of a previously published cut-off for PT IgG of 125 EIA units (EU)/ml. Completed questionnaires were obtained from 115 students, of whom 85 (74%) reported coughing symptoms, including 32 (28%) who met the clinical case definition for pertussis. B. pertussis was detected by PCR in 17 (15%) and WC IgA in 22 (19%) students; neither correlated with symptoms, but dormitory of residence strongly predicted PCR status. The mean PT IgG geometric mean concentration, in this situation of high pertussis exposure, correlated with severity of symptoms and was significantly higher in both symptomatic and asymptomatic children exposed during the outbreak (P<0·001) than in control children. A cut-off for PT IgG of 125 EU/ml was too high in an outbreak situation to be sensitive enough to identify pertussis cases. A case of pertussis in a crowded boarding-school dormitory resulted rapidly in an outbreak. Serology and PCR were useful in identifying the outbreak and commencing disease control measures. The use of serology has mostly been evaluated in community serosurveys, where it is not possible to determine if immunity reflects vaccination, asymptomatic disease or symptomatic disease. This outbreak gave us the opportunity to evaluate the value of serology and PCR in the presence of confirmed exposure to pertussis.

Data from AIDS surveillance systems in the World Health Organization European region (1993–2001) were analysed to describe the main epidemiological aspects of recurrent bacterial pneumonia (RBP) as AIDS-defining illness (ADI) in Europe. Among the 153756 AIDS cases analysed, 5796 (3·8%) had RBP. The proportion of RBP was higher (8·3%) in eastern than in western Europe (3·6%), possibly because of a greater propensity of certain countries to diagnose RBP. In western Europe, the proportion of RBP as ADI appeared to increase over time up to 1998 (from 2·5% to 4·5%), and declined thereafter (3·3% in 2001). RBP was strongly associated with intravenous drug use (odds ratio 3·0, 95% CI 2·7–3·3), whereas it did not differ in age groups or geographical areas. The study findings confirm the crucial role of intravenous drug use in the occurrence of RBP and suggest that highly active antiretroviral therapies might have had a postponing impact on the relative frequency of RBP as ADI.

We estimated age-specific herpes zoster (HZ) incidence rates in the Kaiser Permanente Northwest Health Plan (KPNW) during 1997–2002 and tested for secular trends and differences between residents of two states with different varicella vaccine coverage rates. The cumulative proportions of 2-year-olds vaccinated increased from 35% in 1997 to 85% in 2002 in Oregon, and from 25% in 1997 to 82% in 2002 in Washington. Age-specific HZ incidence rates in KPNW during 1997–2002 were compared with published rates in the Harvard Community Health Plan (HCHP) during 1990–1992. The overall HZ incidence rate in KPNW during 1997–2002 (369/100000 person-years) was slightly higher than HCHP's 1990–1992 rate when adjusted for age differences. For children 0–14 years old, KPNW's rates (182 for females, 123 for males) were more than three times HCHP's rates (54 for females, 39 for males). This increase appears to be associated with increased exposure of children to oral corticosteroids. The percentage of KPNW children exposed to oral corticosteroids increased from 2·2% in 1991 to 3·6% in 2002. Oregon residents had slightly higher steroid exposure rates during 1997–2002 than Washington residents. There were significant increases in HZ incidence rates in Oregon and Washington during 1997–2002 among children aged 10–17 years, associated with increased exposure to oral steroids.

Three sources of data (general practice episode data from the Weekly Returns Service of the Royal College of General Practitioners, national hospital admission data for England and national mortality data by date of death) were examined separately in each winter (1994/1995 to 1999/2000) to investigate the impact of influenza on circulatory disease. Weekly data on incidence (clinical new episodes) hospital emergency admissions and deaths certified to circulatory disorders and to respiratory diseases (chapters VII and VIII of ICD9) during influenza epidemic periods (defined from combined clinical/virological surveillance) were examined in age groups 45–64, 65–74 and [ges ]75 years. Data collected in the four winters in which there were substantial influenza A epidemics were consolidated for the period 6 weeks before to 6 weeks after each peak of the epidemic, and associations between the variables at different time lags examined by calculating cross-correlation coefficients. We also examined deaths due to ischaemic heart disease (IHD) as a proportion of all circulatory deaths and deaths due to influenza/pneumonia as a proportion of all respiratory deaths. There were no increases of GP episodes nor of emergency admissions for circulatory disorders in any of the three age groups during epidemic periods. Increased circulatory deaths occurred in all age groups and particularly in the oldest group. The large cross-correlation coefficients of deaths (circulatory and respiratory) with GP respiratory episodes at weekly lags of 0, −1 and 1 were evidence that the deaths and episode distributions were contemporaneous. The ratios of excess circulatory deaths relative to excess respiratory deaths during epidemic periods were 0·74 (age 45–64), 0·72 (65–74) and 0·57 ([ges ]75 years). Increased circulatory deaths contemporary with new incident cases of respiratory episodes but with no concomitant increase in admissions suggests rapid death during the acute phase of illness. Influenza contingency planning needs to take account of these deaths in determining policy for prophylaxis and in providing facilities for cardio-respiratory resuscitation.

A new B/Shangdong/7/97-like influenza virus (Victoria/2/87 lineage) predominated during the 2002/2003 epidemic season in Finland and was estimated to account for 2246 of the 13496 feverish upper respiratory tract infections (URIs) occurring among conscripts in the Finnish army. The incidence (1716/10000 conscripts) was indicative of moderate epidemic activity at most. Analysis of the cross-reactive antibodies induced in 1988 suggests that the basis of the protection was probably established during the childhood of the conscripts. Vaccination in autumn 2002 prevented 42% of the URIs during the influenza B outbreak and 71% (95% CI 42–85) of infections interpreted as influenza B. Despite the low genetic variability of the Shangdong/7/97-like viruses, breakages of a potential glycosylation site in haemagglutinin (HA1, position 197) were frequent; their biological significance is discussed. The Shangdong/7/97-like strains were HA1/NA reassortants, as were also the less abundant strains that for HA1 belonged to the B/Yamagata/16/88 lineage. A further reassortment, which probably emerged during the outbreak in one of the garrisons, supports our hypothesis that circumstances in these settings may especially favour the emergence of diversity by reassortment.

Three outbreaks of respiratory illness associated with human coronavirus HCoV-OC43 infection occurred in geographically unrelated aged-care facilities in Melbourne, Australia during August and September 2002. On clinical and epidemiological grounds the outbreaks were first thought to be caused by influenza virus. HCoV-OC43 was detected by RT–PCR in 16 out of 27 (59%) specimens and was the only virus detected at the time of sampling. Common clinical manifestations were cough (74%), rhinorrhoea (59%) and sore throat (53%). Attack rates and symptoms were similar in residents and staff across the facilities. HCoV-OC43 was also detected in surveillance and diagnostic respiratory samples in the same months. These outbreaks establish this virus as a cause of morbidity in aged-care facilities and add to increasing evidence of the significance of coronavirus infections.

Human respiratory syncytial virus (hRSV) transmission dynamics are inherently cyclical, and the observed genetic diversity (between groups A and B) also appears to have a repeating pattern. A key unknown is the extent to which genetic variants interact immunologically, and thus impact on epidemiology. We developed a novel mathematical model for hRSV transmission including seasonal forcing of incidence and temporary intra- and inter-group partial immunity. Simultaneous model fits to data from two locations (England & Wales, UK, and Turku, Finland) successfully reproduced the contrasting infection dynamics and group A/B dominance patterns. Parameter estimates are consistent with direct estimates. Differences in the magnitude and seasonal variation in contact rate between the two populations alone could account for the variation in dynamics between these populations. The A/B group dominance patterns are explained by reductions in susceptibility to and infectiousness of secondary homologous and heterologous infections. The consequences of the observed dynamic complexity are discussed.

From July to October 2001, 215 cases of aseptic meningitis occurred among the inhabitants of the German city of Kassel and neighbouring counties. A matched case-control study identified bathing in a public, nature-like pond during the beginning of the outbreak as a risk factor for disease [matched odds ratio (mOR) 44·8, 95% confidence interval (CI) 3·9–515·6]. Among bathers, patients with meningitis spent more time in the water (mOR 18·8, 95% CI 2·0–174·1) and swallowed water more frequently (mOR=7·3, 95% CI 0·7–81·8). Of 30 cerebrospinal fluid samples tested, echovirus 30 was cultured from 16, and echovirus 13 from seven. An echovirus 30 sequence obtained from one pond water sample showed a 99% nucleotide and 100% amino-acid homology with patient isolates. This outbreak demonstrates the potential of nature-like swimming ponds to cause widespread community infection with substantial public health impact.

This study was undertaken to provide first-time estimates for the seroprevalence of parvovirus B19 infection among daycare educators in Montréal, Canada, and to identify factors associated with seropositivity. A cross-sectional design was used. Directors and educators from 81 daycare centres (DCCs) were surveyed about DCC and personal characteristics respectively, and serum samples from 477 female educators were tested for parvovirus B19 IgG antibodies. The seroprevalence of parvovirus B19 was 70%. Parvovirus B19 seropositivity was significantly associated with age and with working experience in DCCs, but the latter association was restricted to educators aged less than 40 years. In conclusion, working as a daycare educator appears to be associated with increased risk of acquiring parvovirus B19 infection, but this finding will require further investigation. Because of the large proportion of educators susceptible to acquiring parvovirus B19 infection, our findings also highlight the need for preventive measures.

This prospective, multicentre study was conducted during 2–30 April 2001 in the internal medicine/infectious diseases services in France and included data from 1858 hepatitis C virus (HCV)-infected patients, half of whom were HIV co-infected. The aims were to outline the type of pre-therapeutic evaluation of HCV infection performed (HCV RNA, genotype, liver biopsy); determine the proportion and characteristics of patients receiving antiviral treatment; and determine if any changes in these parameters had occurred between 1995 and 2001. Patients whom had a complete pre-therapeutic evaluation (39%, 709/1834) and received antiviral treatment (38%, 690/1830) were more likely to have abnormal liver biochemistry, cirrhosis and cryoglobulinaemia (P<0·001). Injecting drug users and HIV-co-infected patients were less likely to have a complete pre-therapeutic evaluation or receive antiviral treatment (P<0·001). A complete pre-therapeutic evaluation was more often performed in 2001 than in 1995 (39% vs. 6%, P<0·001), including qualitative HCV RNA testing (91% vs. 68%, P<0·001), genotyping (59% vs. 7%, P<0·001) and a liver biopsy (60% vs. 29%, P<0·001). The frequency of anti-HCV treatment approximately doubled between 1995 and 2001 (20% vs. 38%, P<0·001). Although adherence to consensus recommendations regarding pre-therapeutic evaluation is not ideal, a substantial improvement has occurred since 1995. Nevertheless, means of increasing the availability of antiviral therapies, particularly for patients with HIV co-infection or injecting drug use, require further study.

Serological assays using dried blood spots from 5221 women in rural areas of eastern Zimbabwe were used to assess the epidemiology of Trichomonas vaginalis infection, and its association with HIV. Antibodies to T. vaginalis and to HIV were detected by enzyme immunoassays. Behavioural and demographic data were collected by confidential questionnaires. In total, 516 (9·9%) women were seropositive for T. vaginalis and seroprevalence increased with age among younger women. Divorced, widowed and single women were more likely to be seropositive. After controlling for age, seropositivity was significantly associated with being sexually active, having multiple sex partners, having a partner who had multiple sex partners, and having a new sex partner in the past year. Seropositivity was associated with a recent history of genital discharge. Overall, 208 (40·3%) T. vaginalis-positive samples were also positive for HIV, compared with 1106 (23·5%) T. vaginalis-negative samples (age and sex adjusted OR 2·11, 95% CI 1·74–2·55, P<0·001). There was increased risk for being HIV-positive amongst T. vaginalis-seropositive women regardless of residence, employment or education. In a logistic regression controlling for common risk factors, the association remained significant. T. vaginalis-seropositive young women with a history of genital discharge were much more likely to be HIV-positive than women who were T. vaginalis-seronegative and had no history of discharge (OR 6·08, 95% CI 2·95–12·53). Although a causal relationship cannot be assumed, detection and treatment of trichomoniasis may be important in strategies to reduce HIV transmission through sexually transmitted infection control.

Susceptibilities to amphotericin B and fluconazole of 628 clinical yeast strains collected from 22 hospitals in Taiwan were determined. A total of 53 isolates (8·4%) were resistant to fluconazole. Each hospital had different resistance rate to fluconazole ranging from 0% to 24%. None of the 186 isolates from eight of the 22 hospitals was resistant to fluconazole. In contrast, isolates from nine of the remaining 14 hospitals had greater than 10% resistance rate to fluconazole. Consistently, 88·9% (8/9) fluconazole-resistant C. albicans isolates were from hospitals having a high resistance rate to fluconazole. The prevalence of various Candida spp. in each hospital was different. A positive association was found between the prevalence of C. tropicalis and the resistance rate to fluconazole for individual hospitals. Although only three isolates (0·5%) were resistant to amphotericin B, a co-resistance to both amphotericin B and fluconazole was observed, which highlights the emerging problem of drug resistance.

An expedition across the Asian part of the Black Sea coast and national parks of Northern Turkey was organized in the summer of 2001 to investigate the presence of Borrelia burgdorferi sensu lato (s.l.), Lyme borreliosis agent, and Anaplasma phagocytophilum, human granulocytic ehrlichiosis agent, in wild mice. A total of 65 Apodemus flavicollis, Apodemus sylvaticus, Microtus epiroticus, Crocidura suaveolens and Mus macedonicus, were captured. Two out of 22 Apodemus sylvaticus specimens were seropositive for B. afzelii by enzyme-linked immunosorbent assay as confirmed by Western blotting, however cultures of skin and bladder samples from all small mammals in Barbour–Stoenner–Kelly's medium-II remained negative for B. burgdorferi s.l. All sera tested were negative for Anaplasma phagocytophilum by indirect immunofluorescent assay. The prevalence of B. burgdorferi s.l. and Anaplasma phagocytophilum is low in wild mice of the Asian part of Northern Turkey.

Contagious bovine pleuropneumonia (CBPP) is a cattle respiratory disease that represents one of the major threats to cattle health and production in sub-Saharan Africa. The transmission contact rate of CBPP plays a key role in the spreading dynamics of the disease. We have developed an approach based on the combination of a SEIR model describing the spread of CBPP with the dynamic of seroconversion to determine the transmission contact rate for CBPP. This method has been subsequently applied to serological diagnostic data obtained from an experimental vaccine trial. As a result, we find that the transmission contact rates for subclinical, clinical and chronic infective states are respectively, 0·084/N, 0·45 and 0·14/N per animal per day, where N is the herd population size, and the basic reproductive number corresponding to this trial (N=28) is R0=27.

Equine grass sickness (EGS) is a largely fatal, pasture-associated dysautonomia. Although the aetiology of this disease is unknown, there is increasing evidence that Clostridium botulinum type C plays an important role in this condition. The disease is widespread in the United Kingdom, with the highest incidence believed to occur in Scotland. EGS also shows strong seasonal variation (most cases are reported between April and July). Data from histologically confirmed cases of EGS from England and Wales in 1999 and 2000 were collected from UK veterinary diagnostic centres. The data did not represent a complete census of cases, and the proportion of all cases reported to the centres would have varied in space and, independently, in time. We consider the variable reporting of this condition and the appropriateness of the space–time K-function when exploring the spatial-temporal properties of a ‘thinned’ point process. We conclude that such position-dependent under-reporting of EGS does not invalidate the Monte Carlo test for space–time interaction, and find strong evidence for space–time clustering of EGS cases (P<0·001). This may be attributed to contagious or other spatially and temporally localized processes such as local climate and/or pasture management practices.

A prevalence study of verotoxin-producing Escherichia coli O157 (VTEC O157) was performed in 371 randomly selected dairy herds distributed throughout Sweden. Faecal and manure samples were collected and analysed by immunomagnetic separation and culturing. Data were recorded for each herd regarding herd size, age of sampled animals and whether, in addition to cattle, the farm kept other animals. VTEC O157 was isolated from 33 (8·9%) of the 371 investigated herds. The prevalence was higher (23·3%) in Halland county than in the rest of Sweden (P>0·01). Halland was also the county in Sweden that during the study period had the highest incidence of human VTEC O157 cases. VTEC O157 was not detected on any farm in northern Sweden. Identified risk factors, in the multivariate analyses, for herds being VTEC O157 positive were herd size, geographical localization, presence of pigs on the farm and median age of sampled animals.

Faecal samples of 2660 domestic animals from 116 farms and 956 samples of food were examined for the presence of Shiga toxin-producing Escherichia coli (STEC). STEC was recovered from 126 (15·3%) cattle, 135 (11·3%) pigs, 135 (66·8%) sheep, 31 (73·8%) goats, 4 (1%) chicken, and 15 (1·6%) food samples. Of all STEC isolates, 21·5, 25·8 and 15% produced enterohaemolysin, α-haemolysin, and aerobactin respectively, 1·6% displayed localized adherence (LA) to HEp-2 cells, 27·6% were sorbitol negative, and 30% were resistant to antibiotics. Only 14 (3·1%) of the STEC isolates belonged to human infection-associated serogroups (O26, O55, O111, O128 and O157), designated as enterohaemorrhagic E. coli (EHEC). This study revealed that STEC are prevalent in domestic animals, and to a lesser extent in food of animal origin in Serbia, but the absence of a EHEC phenotypic profile (characteristic serogroup, LA, enterohaemolysin production) in most animal STEC strains may explain the low incidence of human STEC infection in this part of the world.