This study aimed to evaluate the relationship between HSV-2 infection and several socio-demographic and sexual practices of Mexican and Central American female sex workers (FSWs) in the Soconusco region in the State of Chiapas, Mexico. A cross-sectional study was carried out based on a sample frame of bars where FSWs were active in the Soconusco region. FSWs consented to investigations and answered a questionnaire and provided a blood sample for specific HSV-2 antibody analysis.

One hundred and sixteen bars were studied and 484 women were interviewed. The overall frequency of HSV-2 infected women was 85·7%. Variables that reflected exposure to HSV-2 were significantly associated with the frequency of the infection. Additionally, variables such as education and country of origin were significantly associated with HSV-2 infection. These results suggest that this infection is highly endemic in the Soconusco, posing a health risk for the study population.

The aim of this population-based retrospective study was to determine the incidence of hospitalization for community-acquired, laboratory-confirmed respiratory syncytial virus (RSV) infection in an unselected paediatric population from southern Europe. The study was performed in an area with 15700 children aged less than 5 years attended by a single hospital. The presence of RSV in nasopharyngeal aspirates from children with acute respiratory infection treated in the hospital was investigated in four seasons (July 1996–June 2000). A total of 390 episodes of hospitalization for RSV infection were detected and 83·3% of the children were aged less than 1 year old. The annual hospitalization rate was 37/1000 for infants aged less than 6 months and 25/1000 for those aged less than 1 year. During the study period, 2·5% of the infants younger than 1 year and approximately 5% of those younger than 3 months were hospitalized for RSV infection. The mean length of hospital stay was 5·9 days. Seven per cent of the patients required admission to the intensive care unit and more than half of these children were aged less than 1 month. In Spain, community-acquired RSV infection is a highly frequent cause of hospitalization in young children, especially in those aged less than 1 year. Prevention of RSV infection, through the development of vaccines and/or other strategies, should be a public health priority.

To enhance our understanding of the epidemiology and transmission dynamics of varicella in the pre-vaccine era we performed a serosurvey using opportunistically collected sera submitted to diagnostic laboratories across Australia during 1997–1999. A representative sample by state and sex of 2027 sera from persons aged 1–49 years was tested using an enzyme immunoassay method. The average age of infection and age-specific forces of infection (the probability that a susceptible individual acquires infection) were calculated using published methodologies. Seropositivity increased with age, with 83% of sera positive by ages 10–14 years. The highest force of infection was in the 5–9 years age group (0·195 per susceptible year) followed by the 0–4 years age group (0·139 per susceptible year) and the average age of infection was 8·15 years. These results provide valuable baseline information to measure the impact of vaccination and indicate that vaccination should be aimed at children less than 5 years of age, although further modelling using the serosurvey data is warranted.

A cluster of three cases of listeriosis cases occurred against a background of endemic listeriosis in Western Australia. Human and environmental isolates of Listeria monocytogenes obtained during the outbreak investigation were rapidly subtyped by automated ribotyping using an EcoRI protocol and a RiboPrinter®. DNA macrorestriction analysis by pulsed-field gel electrophoresis (PFGE) was used to confirm the relatedness of isolates. Serogroup 1/2 predominated among the food samples and the four clinical isolates from the outbreak cluster were also of this serogroup. All isolates from chicken material were serogroup 1/2 and indistinguishable by ribotype pattern. PFGE subdivided strains of this ribotype into four subtypes. The preliminary analysis had an immediate impact on hypothesis generation, environmental health investigations, environmental specimen collection and initial control measures. Sufficient typing data to guide environmental health and disease control initiatives was generated in less than one week by combining automated ribotyping with PCR-based detection of L. monocytogenes in suspect foodstuffs and an L. monocytogenes DNA probe. There were no further cases of bacteriologically confirmed listeriosis in Western Australia for six months after completion of the investigation.

We evaluated improvements made to the mandatory notification surveillance system for Legionnaires' disease in France by estimating its sensitivity in 1995 and 1998 using a repeat capture–recapture method. A case of Legionnaires' disease was defined as a person treated for pneumonia in whom legionella had been detected. Patient details were collected from (1) mandatory notifications; (2) the National Reference Centre for Legionella; (3) a postal survey of all hospital laboratories. The three sources were cross-matched and 715 individual cases were identified. A log-linear model, which included an interaction term between mandatory notifications and both the National Reference Centre and Laboratory sources, provided an estimated total of 1124 cases (95% CI 973–1275) in 1998, a twofold increase compared with 1995. The sensitivity of the surveillance system improved from 10% in 1995 to 33% (95% CI 29–38%) in 1998. Capture-recapture methods are important tools in the evaluation of surveillance systems.

The aim was to estimate the community incidence and risk factors for all-cause pneumonia in children in Western Sydney, Australia. A cross-sectional randomized computer-assisted telephone interview was conducted in July 2000, in Western Sydney. Parents of 2020 children aged between 5 and 14 years were interviewed about their child's respiratory health since birth. No verification of reported diagnosis was available. Logistic regression analysis was used to determine risk factors for pneumonia. A lifetime diagnosis of pneumonia was reported in 137/2020 (6·8%) children, giving an estimated incidence in the study sample of 7·6/1000 person-years. Radiological confirmation was reported in 85% (117/137). Hospitalization was reported in 41% (56/137) and antibiotic therapy in 93% (127/137) of cases. Using logistic regression modelling, statistically significant associations with pneumonia were a reported history of either asthma, bronchitis or other lung problems and health problems affecting other systems. In most cases, the diagnosis of asthma preceded the diagnosis of pneumonia. The community incidence of all causes of pneumonia is not well enumerated, either in adults or in children. This study provides community-based incidence data. The incidence of hospitalization for pneumonia in this study is comparable to estimates from studies in comparable populations, suggesting that retrospective parental report for memorable events is likely to be valid. We found a relationship between pneumonia and childhood respiratory diseases such as asthma, which has implications for targeted vaccination strategies.

We investigated primary human herpesvirus-6 and -7 (HHV-6, HHV-7) infections as a cause of rashes incorrectly diagnosed as measles in Brazilian children. Sera from 124 patients, aged 4 months to 17 years, from the states of Rio de Janeiro and Espírito Santo, in whom measles, rubella and parvovirus B19 infections had been excluded, were studied using indirect immunofluorescence antibody avidity tests; 38 (31%) had evidence of primary HHV-6 and/or HHV-7 infections. Twenty four children had primary HHV-6 infection, either recent or coincident with the rash, and similarly 31 had primary HHV-7 infection. Remarkably, almost half (17) of primary infections were dual HHV-6 and HHV-7 infections with the majority, 12 (71%), in children less than 1 year old. HHV-7 infection occurred earlier than previously reported, perhaps due to socioeconomic and tropical conditions in this region of Brazil, and thus coincided with the HHV-6 infections. This study also highlights the difficulties of diagnosing a rash illness on clinical grounds alone.

Japanese encephalitis (JE) is a serious health problem in the southwestern region of Nepal. Serological diagnostic kits for routine diagnostic use in this region have not been available. This study was performed to examine if the particle agglutination (PA) assay for Japanese encephalitis virus (JEV) IgM could be applicable to the samples collected in Nepal and also to evaluate the accuracy of clinical diagnosis of JE. One hundred and ninety-three blood samples were collected from the patients clinically diagnosed with JE or other infectious diseases in the JE-endemic, southwestern region of Nepal, in 2000. The PA assay was performed on these 193 serum samples and the results were compared with those by IgM-capture ELISA. Eighty-six samples were IgM-positive by the PA assay, and 71 of 86 were also positive by IgM-capture ELISA (sensitivity, 99%; specificity, 88%; positive predictive value, 0·82; negative predictive value, 0·99). These results suggest that the PA assay is a simple, reliable and useful diagnostic test to support clinical diagnosis in rural hospitals of Asia including Nepal.

The aim of this study was to compare the incidence of community-acquired Legionnaires' Disease in Nottingham with England and Wales and to explore reasons for any difference observed. Based on data from the National Surveillance Scheme for Legionnaires' Disease (1980–1999), the rate of infection in England and Wales was 1·3 per million/year compared with 6·6 per million/year in Nottingham. Domestic water samples were obtained from 41 (95%) of 43 Nottingham cases between 1997 and 2000. In 16 (39%) cases, Legionella sp. were cultured in significant quantities. Proximity to a cooling tower was examined using a 1[ratio ]4 case-controlled analysis. No significant difference in the mean distance between place of residence to the nearest cooling tower was noted (cases 2·7 km vs. controls 2·3 km; P=0·5). These data suggest that Nottingham does have a higher rate of legionella infection compared to national figures and that home water systems are a source.

The incidence rate of giardiasis in New Zealand is one of the highest among developed countries, peaking in the 1–4 year age group. A case–control study was undertaken to identify risk factors for giardiasis among Auckland children under 5 years of age. The exposure history of 69 cases and 98 controls were analysed. Ninety-five per cent cases and 86% controls used water from the Auckland Metropolitan mains (AMM) supply for domestic purpose, 44 cases and 42 controls swam and 59 cases and 54 controls wore nappies. Children wearing nappies were at significantly increased risk of the disease (OR=3·0, 95% CI=1·01–8·9), as were those from households which had more than one child wearing a nappy (6·5, 1·8–23·4). The Auckland metropolitan mains water supply was associated with a reduced risk compared to other drinking water sources. Significantly increased risks were also associated with drinking water consumed away from home (4·7, 2·2–10·1), swimming at least once a week (2·4, 1·1–5·3) and travelling domestically (2·5, 1·03–6·0). The study identified vulnerable groups and modifiable risk factors for diarrhoeal diseases, particularly Giardia infection. Nappy wearing was an independent risk factor for infection. Further study is advocated to ensure better protection of public health, especially for children.

In a study to estimate the frequency of Cryptosporidium infections in Switzerland, stool samples from patients found to be positive for Cryptosporidium spp. by modified Ziehl–Neelson staining and fluorescence microscopy were used for genotyping experiments. With 9 of 12 samples, DNA extraction and subsequent genotyping was successful. All Cryptosporidium-isolates belonged to the bovine genotype. In one stool sample, two strains of Cryptosporidium were demonstrated, suggesting a mixed infection. In comparison with reference strains from calves, one of the isolates showed a full sequence identity and the other a similarity of 97·5%. The fact that only bovine genotypes were detected suggests, that cryptosporidiosis must primarily be considered as a zoonotic disease in Switzerland. This is in contrast to other countries, where the human genotype of C. parvum was shown to dominate the epidemiological situation. The results of our study are supported by the previous finding, that two of the analysed strains originated from patients who used to consume raw milk or raw cream, a known risk factor for cryptosporidiosis.

The aims of this descriptive study were to confirm the high incidence of subacute sclerosing panencephalitis (SSPE) previously reported from Papua New Guinea (PNG) and to relate SSPE to previous measles vaccination and measles illness. From February 1997 to April 1999 we diagnosed a total of 55 patients with SSPE at Goroka Base General Hospital in Eastern Highlands Province (EHP) of PNG. The diagnosis was based on high cerebrospinal fluid and serum measles virus antibody titres with progressive neurological disorder and myoclonic jerks. Of these 55 patients 42 were from EHP, including 32 whose onset was in the 2-year period 1997–1998. The annual incidence of SSPE in EHP in these 2 years was 98 per million population under 20 years of age, the highest ever reported. This incidence was more than ten times higher than the highest incidence in the prevaccine era reported from elsewhere. The mean age of onset of SSPE was 7·7 years (range 2·8–14·8 years) and the interval between measles and the onset of SSPE, where known, had a mean of 5·9 years and a range of 2·5–11·1 years. Among the SSPE patients 19 had a documented history of measles vaccination. Eight of these 19 also had documentation of previous measles illness; of these, seven were vaccinated after the development of measles and one was vaccinated 20 days before measles illness. Two non-SSPE children received vaccination twice which was documented and subsequently developed measles which was also substantiated by documentation. Two patients with SSPE yielded amplified nucleotide sequences of measles virus that were different from any of the vaccine strains. We found no evidence to implicate measles vaccination in the development of SSPE.

By the end of December 2000, the epidemiological system ‘Alert’ of the Public Health Institute in Tirane reported an outbreak of acute gastroenteritis. The outbreak involved children in Tirane and in the rural area. In total, 2722 children were seen in Tirane Hospital and 982 (56·4%) were treated for acute gastroenteritis. The age group with the highest morbidity was 0–5 years (89·7%), followed by the 6–9 (6·2%) and 10–15 years age groups (4·1%). The distribution of acute gastroenteritis cases, which occurred along the same water distribution system, suggests a waterborne origin. The nucleic acid amplification confirmed the co-circulation of different genotypes of rotavirus, mainly P[8]G9 and P[8]G3, responsible for the outbreak. Other enteric viruses such as astrovirus serotype 1, adenovirus and Norovirus, genogroups I and II were detected. Co-infections with different rotavirus genotypes and even with different enteric viruses were detected in several samples.

We investigated whether there are differences between the natural history of B and C chronic hepatitis in a southern Italian population, and whether the chronic viral hepatitis population was modified by the introduction of the anti-HCV test in 1989. We examined clinical charts of 1120 patients consecutively admitted to our division from January 1979 to December 1998 with the histological diagnosis of chronic viral hepatitis (304 from 1979 to 1988; 816 from 1989 to 1998). We found significant differences only in age at diagnosis (higher in the second decade, P=0·001), and in aetiology (HBV decreased in the second decade, P<0·0001). We were able to follow up 449 patients for 2–20 years (311 with HCV and 138 with HBV infection), and found that chronic HCV evolved to cirrhosis more frequently than did chronic HBV; but in both types time to development of cirrhosis and the incidence of death were similar. Our data confirm that a higher onset age of HBV and of HCV is frequently observed in those subjects who have a faster disease progression.

A cross-sectional study of 694 children aged 2 to 45 months selected from 30 clusters throughout the city of Salvador, Bahia (pop. 2·3 million) was carried out as part of a longitudinal study of diarrhoea in order to identify risk factors for infection with Giardia duodenalis. Variables studied included three social and demographic factors (such as mother's education and marital status), five relating to the peri-domestic environment (rubbish disposal, open sewers, paving of the street), seven relating to the home itself (house construction, susceptibility to flooding, water supply and sanitation) as well as a score for hygiene behaviour based on structured observation. After multivariate analysis using a hierarchical model, only four significant risk factors were found: (a) number of children in the household under five years (b) rubbish not collected from the house (c) presence of visible sewage nearby, and (d) absence of a toilet. All four were significant at the 1% level.

Because non-name-based case registries have recently been used for reporting human immunodeficiency virus infection, this study attempted to define the sensitivity, specificity and accuracy of case registry matches using non-name-based registries. The AIDS, sexually transmitted disease (STD), and tuberculosis (TB) case registries were matched using all available information to establish the standard. The registries were then matched again using five increasingly less specific criteria to compare sensitivity, specificity and accuracy. The registries were then also transformed into non-name-based codes as if they were the HIV registry and matched again. With name-based registries, sensitivities increased as the matching criteria became less exacting, while the accuracy declined slightly. Specificities remained close to 100% due to the relatively small number of matched cases. Results from matches of non-name-based registry matches were similar to those of the name-based registry matches. Non-name reporting can be used for data matching with acceptable accuracy.

Between 1992 and 1999, 93 cases of blastomycosis, including 25 laboratory confirmed cases, were identified in Missouri (annual incidence, 0·2/100000 population). Mississippi County in southeastern Missouri had the highest incidence (12/100000) with a much higher rate among blacks than whites in this county (43·2/100000). The mortality rate, 44% was also higher among blacks. To determine risk factors for endemic blastomycosis, a case-control study was conducted among southeastern Missouri residents. Independent risk factors for blastomycosis were black race and a prior history of pneumonia. No environmental exposures or socioeconomic factors were significantly associated with increased risk. The increased risk among blacks may possibly be related to genetic factors, but further studies are needed to clarify this. However, heightened awareness of the disease and a better understanding of the risk factors are important and may lead to earlier diagnosis and start of treatment, possibly improving outcome.

The aims of the study were to compare the burden of varicella and herpes zoster in Australia. No national surveillance exists for varicella or herpes zoster. We used hospital morbidity data from 1993–9 and pharmaceutical prescribing data from 1995–9.

In the financial year 1998/99, there were 4718 hospitalizations for zoster compared to 1991 for varicella. For varicella the mean age of patients was 15 years compared to 69 years for zoster. The mean length of stay in hospital was 4·2 days for varicella and 12·7 days for zoster. Varicella accounted for 8396 (3726 with principal diagnosis varicella) bed days compared to 26266 (5382 with principal diagnosis of zoster) for zoster. The in-hospital case-fatality rate was 0·4% for varicella and 1% for zoster. In 1999, 59200 community-based cases of zoster were treated with antivirals. We estimate that 157266 cases of zoster occurred in the community in 1999, a rate of 830 per 100000 population.

Herpes zoster has a higher burden of disease than varicella, and must be a component of disease surveillance in order to determine the full impact of vaccination on the epidemiology of varicella zoster virus (VZV).

Seroconversion illness is known to be associated with more rapid HIV disease progression. However, symptoms are often subjective and prone to recall bias. We describe symptoms reported as seroconversion illness and examine the relationship between illness, HIV test interval (time between antibody-negative and anibody-positive test dates) and the effect of both on time to AIDS from seroconversion. We used a Cox model, adjusting for age, sex, exposure group and year of estimated seroconversion. Of 1820 individuals, information on seroconversion illness was available for 1244 of whom 423 (34%) reported symptomatic seroconversion. Persons with a short test interval ([les ]2 months) were significantly more likely to report an illness than people with a longer interval (OR 6·76, 95% CI 4·75–9·62). Time to AIDS was significantly faster (P=0·01) in those with a short test interval. The HIV test interval is a useful replacement for information on seroconversion illness in studies of HIV disease progression.

During the period January 1998–December 2001, all Danish broiler flocks were monitored bacteriologically for thermophilic campylobacters and isolates were stored at −80 °C. Six neighbouring broiler farms in a small community were selected for detailed examination of all Campylobacter jejuni isolated (n=180) from these farms during 1998–2000 using Penner serotyping and pulsed-field gel electrophoresis (PFGE). The area and the farms were selected according to their prevalence of campylobacter so that both farms with low and high frequencies of campylobacter positive flocks were included in the study. The frequency of campylobacter positive flocks on the six farms ranged from 24·5 to 72·7%. One hundred and eighty of the isolates were C. jejuni (included in this study), 14 isolates were C. coli whereas 7 isolates belonged to other species but were not further identified. By serotyping of all C. jejuni 56 isolates (31·5%) were assigned to the 4-complex, 32 isolates (18·0%) to serotype 2, 12 isolates (6·7%) to serotype 11, and 11 isolates (6·2%) were assigned to serotype 12. In three farms, 4-complex was the most prevalent serotype, in one farm it was the second most frequently isolated serotype, while serotypes 2 and 1,44, respectively, were the most frequently isolated from the two remaining farms. This serotype distribution differed from the overall country-wide distribution where serotypes 2 and 1,44 are the most prevalent. All serotype 4-complex isolates from the six selected farms were compared by PFGE to serotype 4-complex isolates from the rest of the country. The results showed that there was a high level of diversity among isolates from the whole country, whereas isolates from the six farms were very homogeneous and only displayed one or a few different PFGE patterns on each farm. It is suggested that certain campylobacter clones persist in a confined geographical area, probably at the farm, and that the broiler houses may be repeatedly infected with a few C. jejuni clones during succeeding broiler flocks. New clones may be introduced, however, the sources and vehicles are yet unknown.