Asymptomatic carriage of Neisseria meningitidis is common (5–35% of individuals) while the incidence of invasive meningococcal disease is fairly low (<1–5 per 100000 per annum in Europe). Naturally acquired protective immunity may account for this difference. In this study, we investigated the relationship between anti-meningococcal salivary IgA and age and carriage. We showed that salivary IgA to a range of meningococcal antigens increased successively with age with some specificity for commonly circulating serosubtypes. In a group of 258 students 37 (14%) of whom were carriers of N. meningitidis serogroup B, higher levels of specific IgA were associated with carriage. Stratified analysis revealed a positive relationship between smoking and specific anti-N. meningitidis IgA independent of current carriage, weighted odds ratio (OR) 4·1 (95% CI 1·1–18) and OR 3·8 (95% CI 0·96–16) for reference strains B:1:P1.14 and B:4:P1.5,4 respectively. These data implicate IgA as a factor in host defence from meningococcal invasion, although the precise mechanisms remain uncertain.

The incidence, phenotypic characteristics and antimicrobial resistance patterns of 193 Shigella strains isolated from 2489 hospitalized children with acute diarrhoea were studied during January 2001 to August 2004. S. flexneri (60%) was the most prevalent serogroup, followed by S. sonnei (23·8%), S. dysenteriae (9·8%) and S. boydii (5·7%). Since 2002, S. flexneri 2a was the most dominant serotype. Almost all S. flexneri strains exhibited resistance to ampicillin, co-trimoxazole, tetracycline, nalidixic acid and fluoroquinolones. After a lapse of almost 14 years, S. dysenteriae type 1 strains reemerged for the first time during 2002 and these strains were resistant to more than two antibiotics (multidrug resistance), including fluoroquinolones. An upsurge of similar resistance patterns was also noted among S. flexneri type 2a since December 2003. Resistance to fluoroquinolone increased year on year among S. dysenteriae type 1 and S. flexneri, but not in S. boydii or S. sonnei. Monitoring of antimicrobial susceptibility through a surveillance programme is recommended to select appropriate antibiotics for the effective treatment of shigellosis in this region.

In The Netherlands, in May 1999 an enhanced surveillance of hepatitis B was begun to collect detailed information of patients with acute hepatitis B virus (HBV) infection. The objective was to gain insight in transmission routes and source of infection of new HBV cases. Through public health services, patients were interviewed on risk factors. It appeared that the majority (59%) acquired the infection through sexual contact; 52% of these by homosexual and 48% by heterosexual contact. In 60% of the heterosexual cases, the source of infection was a partner originating from a hepatitis B-endemic region. Sexual transmission is the most common route of transmission of acute hepatitis B in The Netherlands and introduction of infections from abroad plays a key role in the current epidemiology of HBV. As well as prevention programmes targeted at sexual high-risk groups, prevention efforts should focus more on the heterosexual transmission from HBV carriers.

Hepatitis B virus (HBV) infection is endemic in Turkey, but the main routes of transmission were not well established. This study aims to detect the exposure time to HBV and associated risk factors among children. In a sampling group of chıldren aged 0–19 years living in Edirne, antiHBc, antiHBs and HBsAg were screened by the microELISA method. A questionnaire was also completed for each child. In 717 children that were included in the study, the total antiHBc seropositivity was 5·4% and was 1·8, 0·8, 1·7, 6·8, 11·8% in 0–1, 2–5, 6–10, 11–14, 15–19 years age groups respectively. The overall HBsAg seropositivity was 1·7%. The risk of HBV infection increased after the age of 10 years (OR 7·79, 95% CI 3·01–20·16). Collective circumcision was the only independent factor according to regression analysis. Children living in Edirne should be vaccinated against HBV before reaching 11 years of age.

Salivary excretion of rabies virus was evaluated in 14 adult vampire bats (Desmodus rotundus) intramuscularly injected with a large dose (106 MICLD50) of vampire rabies virus variant CASS88. Saliva samples were obtained from surviving bats every other day for 30 days, then weekly for 2 months, and finally 1 and 2 years later. Rabies virus was isolated in murine neuroblastoma cells and in randomly selected cases by PCR. Rabies virus was not detected in the saliva of any of the 11 animals that succumbed (somewhat early) to rabies challenge, nor in the control bats. In contrast, virus was detected early, and only once (days 6, 6 and 21) in each of the three animals that survived rabies challenge and remained healthy for at least 2 years after challenge. At that time even vigorous dexamethasone and cyclosporine administration failed to provoke further viral excretion.

A 10-month longitudinal household study of pre-school children and their families was undertaken with monthly visits collecting epidemiological data and nasopharyngeal swabs in Hertfordshire, England from 2001 to 2002. Pneumococcal culture was with standard methods. In total, 121 families (489 individuals) took part. Mean prevalence of carriage ranged from 52% for age groups 0–2 years, 45% for 3–4 years, 21% for 5–17 years and 8% for [ges ]18 years. Carriage occurred more than once in 86% of children aged 0–2 years compared to 36% of those aged [ges ]18 years. The most prevalent serotypes in the 0–2 years age group were 6B followed by 19F, 23F, 6A and 14. Young children were responsible for the majority of introductions of new serotypes into a household. Erythromycin resistance (alone or in combination) occurred in 10% of samples and penicillin non-susceptibility in 3·7%. Overall the recently licensed 7-valent conjugate vaccine (PCV) would protect against 64% of serotypes with no intra-serogroup cross protection and 82% with such protection. Nasopharyngeal carriage of S. pneumoniae is common in a UK setting in the pre-conjugate vaccine era. PCV would protect against a large proportion of carriage isolates. However, the impact of vaccination on non-vaccine serotypes will need to be monitored.

During a 2-year period, blood samples from 2505 Lebanese blood donors were chosen at random, at various periods of time at one blood donation centre (Hotel Dieu de France, Beirut, Lebanon) and were screened for markers of HBV infection (HBsAg, anti-HBc and anti-HBs). The study showed HBsAg positivity of 0·6% and an overall exposure rate to HBV of 10·0%. Out of the 2505 blood donors screened, 56 (2·2%) were found to be ‘anti-HBc alone’ positive which is almost four times the HBsAg positivity. The 56 ‘anti-HBc alone’ samples were retested by another ELISA kit commercially available and 54 samples were ‘anti-HBc alone’ positive by both assays. The 54 samples had no serological markers as evidence of infection with human immunodeficiency virus (HIV) or hepatitis C virus (HCV). Only seven (13%) out of the 54 samples were HBV DNA positive by PCR and all were HBV genotype D. All seven HBV DNA-positive samples had HBV DNA levels below 400 copies/ml. Although any circulating HBV DNA among our ‘anti-HBc alone’ blood donors was below the detection limit of our Amplicor Monitor assay, some of these samples had circulating virus. A national study, where a larger number of blood donors from different blood donation centres across the country will perhaps determine whether screening for anti-HBc in addition to HBsAg detection is needed in Lebanese blood donors.

The New York State hospital discharge database and the multiple cause-of-death file were used to estimate the mortality rate of hepatitis C in New York State excluding New York City in 1997. The mortality rate with hepatitis C was severely underestimated when each data source was used alone. Applying the capture–recapture method using the hospital discharge database and the multiple cause-of-death file appears to be an efficient method to estimate the mortality rate with hepatitis C.

The purposes of the study were (i) to describe the abundance and epidemiology of Legionellaceae in the man-made environment in a northern Italian area, (ii) to assess the concordance between pulsed-field gel electrophoresis (PFGE) and automated ribotyping (AR) techniques for genotyping L. pneumophila and (iii) to investigate the correlation between serogrouping and genotyping data. Water was sampled from reservoirs in 12 buildings across an area of 80-km radius. Despite the water temperature always being maintained above 55 °C, all of the buildings sampled were contaminated with Legionellaceae on at least one occasion and 63 L. pneumophila isolates representing nine different serogroups were collected. The two DNA methods revealed a high degree of genetic heterogeneity, even though identical L. pneumophila clones were recovered at different sites. The AR technique provided a fairly reliable approximation of PFGE results (73% concordance), however there was poor correlation between serogrouping and genotyping data as identical DNA fingerprints were shared by isolates of different serogroups.

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.

A retrospective study of group A streptococcal (GAS) infections was performed for the period 1985–2002 in an area of central Italy. Although very severe diseases such as streptococcal toxic shock syndrome (STSS) were observed, a general increase in invasive infections was not found. Isolates of GAS were classified by M protein genotyping (emm typing) and analysed according to their origin from invasive and non-invasive infections. The predominant emm types were types 1, 4 and 12, followed by types 3, 6 and 28. During the study period the proportion of isolates of types 1 and 12 fell, while other types (3, 6, 22, 28 and 77) appeared. Isolates from invasive and non-invasive infections shared several emm types; however, most invasive strains belonged to five types only (types 1, 4, 12, 28 and 77), while non-invasive isolates were generally more heterogeneous.

The prevalence of hepatitis C and related risk factors in drug users were compared in two geographic regions in Belgium, the city of Antwerp and the mixed urban–rural area of Limburg. All 310 participants were surveyed and screened for hepatitis B, hepatitis C and HIV. Prevalence rates of anti-HCV, anti-HBc and anti-HIV were 71, 62 and 4% in Antwerp and 46, 21 and 0% in Limburg respectively. Injecting drug use, duration of injecting drug use, work as a commercial sex-worker, originating from Turkey or Northern Africa, marginalization and anti-HBc positivity were identified as independent predictors for hepatitis C infection. In this study an important difference in HCV seroprevalence among drug users in a methadone maintenance programme across two geographic regions in Belgium was demonstrated. This was explained not only by variations in drug-related risk behaviour, but also by differences in sexual risk behaviour and socio-economic status.

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.

In order to determine the susceptibility and serum neutralizing antibody response of Desmodus rotundus to rabies virus, bats were inoculated with a virus isolated from a naturally infected haematophagous bat. Bats were divided into four groups of 10 animals each. Dilutions of rabies virus containing 100, 1000, 10000 and 100000 MICLD50 (lethal dose 50% for mice inoculated by the intracerebral route) were administrated in the pectoral muscle. The presence of rabies virus was detected in brain and salivary glands by fluorescent antibody, mouse inoculation and RT–PCR. The observed mortality for each virus dose was 0, 20, 20 and 60% respectively. Serum neutralizing antibodies were tested for by the rapid fluorescent focus inhibition test, and antibody titres greater than 0·5 IU/ml were found in 53% of bats 30 days after virus inoculation. Resistance to infection was seen in bats that developed low or no detectable antibody response as well as in bats with high titres. Among the 10 bats that died of rabies, eight showed signs of paralytic rabies and two bats showed no clinical signs.

To control plagues of free-living mice (Mus domesticus) in Australia, a recombinant murine cytomegalovirus (MCMV) expressing fertility proteins is being developed as an immunocontraceptive agent. Real-time quantitative PCR was used to monitor the transmission of two genetically variable field strains of MCMV through mouse populations after 25% of founding mice were infected with the N1 strain, followed by the G4 strain 6 weeks later. Pathogen-free wild-derived mice were released into outdoor enclosures located in northwestern Victoria (Australia). Of those mice not originally inoculated with virus, N1 DNA was detected in more than 80% of founder mice and a third of their offspring and similarly, G4 DNA was detected in 13% of founder mice and in 3% of their offspring. Thus, prior immunity to N1 did not prevent transmission of G4. This result is promising for successful transmission of an immunocontraceptive vaccine through Australian mouse populations where MCMV infection is endemic.

In 1992, isolates with a distinctive phage pattern were identified amongst the 186 MRSA recovered in New Zealand. These unusual isolates were recovered in the Auckland region from individuals who came from or had visited Western Samoa, and were called Western Samoan phage pattern (WSPP) MRSA. They were almost exclusively community based and were mainly responsible for the alarming 15-fold increase in MRSA seen in New Zealand over the next 6 years. Since 2000, the number of infections attributable to WSPP MRSA appears to be declining. WSPP isolates are clonal, possess a unique type IV SCCmec element, and a distinctive multilocus sequence allelic profile (ST30). WSPP isolates are invariably not multiresistant with methicillin MICs generally [les ]32 μg/ml. Virulence of the WSPP clone appears to be related to its adhesive and consistent toxin- (e.g. Panton–Valentine leukocidin, α- and γ-haemolysins) producing capabilities. Isolates are most frequently associated with cutaneous lesions in younger age groups. Since 1998, MRSA isolates belonging to the UK-derived EMRSA-15 strain (also type IV SCCmec) have continued to increase in New Zealand, and together with WSPP, these strains now dominate MRSA isolations in New Zealand.

A survey was carried out in two goat herds during a single peste des petits ruminant (PPR) outbreak. Clinical examination showed that animals belonging to the West African Dwarf species had severe symptoms while those belonging to the West African long-legged species had mild symptoms. To confirm and to monitor the disease in each species, the study required specific monoclonal antibody-based diagnostic tools. An association of shedding of PPR virus (PPRV) and acute or mild clinical signs of the disease could be demonstrated by the rinderpest virus (RPV)/PPRV immunocapture ELISA assay. Between 85 and 100% of nasal secretions obtained from clinically diseased goats during the PPR outbreak reacted positively. Parallel serological surveillance for specific measurement of PPR antibodies revealed that between 34·4 and 88·5% of animals with no detectable virus were, however, able to seroconvert and therefore seemed to demonstrate that PPR subclinical infections do occur. Antibodies were shown to impair the RP heterologous vaccination. This evaluation offers new prospects for diagnosis and management of PPRV infection as well as for RPV control.

During the period 2000–2003, wild grey foxes (Urocyon cinereoargenteus) in northern Colombia became infected with rabies. In order to derive phylogenetic relationships between rabies viruses isolated in foxes, dogs and humans in this region, 902 nt cDNA fragments containing the G–L intergenic region and encoding the cytoplasmic domain of protein G and a fragment of protein L were obtained by RT–PCR, sequenced and compared. Phylogenetic analysis showed that rabies viruses isolated in foxes, dogs and humans belonged to a single genetic variant. Speculative analysis together with epidemiological data indicated that rabies in foxes may have been due to contact with rabid dogs. Rabies transmission between dogs, wild foxes and humans may happen in natural conditions in northern Colombia. This finding is the first to suggest dog-to-fox rabies transmission in South America, and provides another example of dog rabies variants being able to successfully colonize wildlife hosts.