Despite a significant public health burden the epidemiology of human Campylobacter infection remains blurred. The identification of demographic determinants for Campylobacter infection is therefore essential for identifying potential areas for intervention. Demographic data from an active, population-based sentinel surveillance system for Campylobacter infection (from 2000 until 2003, n=15 907) were compared with appropriate denominator data from the 2001 United Kingdom Census. Incidence was higher in males from birth until the late teens and in females from 20 to 36 years. Age- and gender-specific differences in Campylobacter incidence were observed in different ethnic and socioeconomic groups and hence are all major drivers for Campylobacter infection. Epidemiological studies on Campylobacter infection need to take these factors into consideration during design and analysis. The collation of detailed epidemiological data and its comparison with appropriate denominator data provides a valuable epidemiological tool for studying infection.

Hepatitis E virus (HEV) is ubiquitous in pigs worldwide and may be zoonotic. Previous HEV seroprevalence estimates for groups of people working with swine were higher than for control groups. However, discordance among results of anti-HEV assays means that true seroprevalence estimates, i.e. seroprevalence due to previous exposure to HEV, depends on choice of seroassay. We tested blood samples from three subpopulations (49 swine veterinarians, 153 non-swine veterinarians and 644 randomly selected individuals from the general population) with one IgM and two IgG ELISAs, and subsets with IgG and/or IgM Western blots. A Bayesian stochastical model was used to combine results of all assays. The model accounted for imperfection of each assay by estimating sensitivity and specificity, and accounted for dependence between serological assays. As expected, discordance among assay results occurred. Applying the model yielded seroprevalence estimates of ~11% for swine veterinarians, ~6% for non-swine veterinarians and ~2% for the general population. By combining the results of five serological assays in a Bayesian stochastical model we confirmed that exposure to swine or their environment was associated with elevated HEV seroprevalence.

A gastroenteritis outbreak occurred in a military camp where a laboratory and epidemiological investigation was carried out. The early onset of symptoms indicated probable food contamination with Clostridium perfringens. Stool samples collected from affected patients were tested within 4 h via real-time polymerase chain reaction (PCR) for the presence of the C. perfringens plc gene. Ten out of the 12 stool samples were positive. Confirmation of the molecular test results was carried out by enumeration of C. perfringens in stool by culture and shown to be in excess of 106 spores/g stool. The isolates obtained from culture were further analysed by PCR for the presence of the chromosomal enterotoxin (cpe) gene. Based on the clinical symptoms, epidemiological and laboratory investigations, C. perfringens was implicated as the aetiological agent. The ability to conduct real-time PCR analysis greatly shortens the time to diagnosis and allows for preventive and control measures to be effected quickly.

This study examined the prevalence of HIV and other sexually transmitted infections (STIs) in pregnant women in Kinshasa, the Democratic Republic of the Congo (DRC). Between April and July 2004, antenatal attendees at two of the largest maternity clinics in Kinshasa were tested to identify HIV status, syphilis, Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG). HIV seroprevalence was 1·9% in 2082 women. With PCR techniques, CT and NG infections were also uncommon in the first 529 women (1·7% and 0·4%, respectively). No active syphilis infection case was identified by Treponema pallidum haemagglutination assay (TPHA) and rapid plasma reagin test (RPR). A woman's risk of HIV infection was significantly associated with her reporting a male partner having had other female sexual partners (OR 2·7, 95% CI 1·2–6·2). The continuing low seroprevalence of HIV in pregnant women from Kinshasa was confirmed. Understanding factors associated with this phenomenon could help prevent a future HIV epidemic in low HIV transmission areas in Africa.

An outbreak of cryptosporidiosis associated with exposure to outdoor swimming-pool water affected an estimated 800–1000 individuals. PCR products were obtained from faecal specimens from 30 individuals who tested positive for Cryptosporidium oocysts. RFLP and sequencing analyses showed that all individuals were infected with Cryptosporidium parvum. Among the infected individuals, five had just swum in an adjacent indoor pool during the same period, and had no identified contact with individuals linked to the outdoor pool. With the use of subgenotyping based on analysis of three mini- and microsatellite loci, MS1, TP14, and GP15, we could identify two sources of exposure. One subtype was associated with the outdoor pool and another with the indoor pool. These data demonstrate that the use of mini- and microsatellite loci as markers for molecular fingerprinting of C. parvum isolates are valuable in the epidemiological investigation of outbreaks.