Hepatitis C virus (HCV) isolates from 93 patients living in Tunisia, including 16 haemophiliacs, were genotyped by INNO LiPA and partial sequencing of the 5′ untranslated region of the viral genome. In non-haemophiliacs, subtype 1b was largely predominant (79%), types 1a, 2a, 2b, 3a and 4a occurred much less frequently at 5, 7, 3, 3 and 1% of cases, respectively. In the group of haemophiliacs, a co-dominance between subtypes 1a and 1b was noticed (38%). Type distribution of HCV in Tunisia differs from that reported in other countries of the Mediterranean and Middle East regions. Genotyping results in respect of clinical status, age, and genotyping methods, are discussed.

We undertook a representative survey of measles antibodies in Addis Ababa, Ethiopia 1994, to characterize immunity and transmission. Specific-antibody levels (IU/l) were determined by ELISA for 4654 sera from individuals aged 0–49 years (1805 <15 years) collected by stratified household-cluster sampling. The proportion seronegative (<100 IU/l) was 20% (95% CI: 16–25) in children 9–59 months old, declining to 9% (7–12) in 5–9 year olds, 5% (4–7) in 10–14 year olds, and <1% in adults. The proportion of children (<15 years old) with low-level antibody (100–255 IU/l) was 8% (7–10). Vaccination and an absence of a history of measles illness were strongly associated with low-level antibody. History of measles vaccination in 9 months to 14-year-old children was ~80%. We estimate a primary vaccine failure rate of 21% (12–34) and continued high measles incidence of 22 per 100 susceptibles (19–24) per annum. Our data support the introduction of campaign vaccination in the city in 1998, although higher routine vaccine coverage is required to sustain the impact. The implications of a high prevalence of low-level antibody are discussed.

From February 1999 to February 2000, 1250 individual broiler chickens representing 125 broiler flocks originating from 62 broiler farms in Denmark were screened for campylobacter carriage. Every month, 10 flocks were tested for campylobacter carriage. The swabs were tested individually and as a pooled sample representing the flocks. Campylobacter spp. carriage was detected from 512 (40·9%) broiler chickens originating from 63 (50·4%) positive flocks. Campylobacter carriage by both individual chickens and flocks showed seasonal variation. Campylobacter jejuni was the dominant species (95·5%). Campylobacter isolates were typed using Penner heat-stable serotyping and flaA-typing methods. Data of campylobacter carriage by individual chickens and data generated by the use of different typing methods contributed to a better understanding of the dynamics of campylobacter infection within the broiler flocks. C. jejuni Penner heat-stable serotype HS2, flaA-type 1 was the most common type found in Danish broiler chickens.

Co-circulating variants of influenza A/H3N2 viruses in children were studied in Houston, Texas between October 1997 and March 1998 to assess the effects of a new variant strain on the severity of clinical illness. Influenza A virus was isolated from the nasal wash or nasal aspirate specimens collected from children at two tertiary care hospitals, and 271 isolates were available for variant-specific subtyping using RT–PCR and restriction fragment length polymorphism (RFLP) analysis. We classified 124 (46%) influenza viruses as A/H3N2/Wuhan/359/95-like and 137 (50%) as A/H3N2/Sydney/05/97-like. Ten (4%) virus isolates could not be classified. Ill contacts in the household were reported more frequently in patients infected with A/Sydney-like viruses than in those infected with A/Wuhan-like viruses (85% vs. 71%, respectively, P=0·02). There were no differences in other demographic variables among children infected with these strains. This study found no increase in illness severity in children infected with a newly emerging strain.

A longitudinal observational study (18 months) was carried out in two Dutch dairy herds to explore clinical, epidemiological and molecular characteristics of Streptococcus uberis mastitis. Infections (n=84) were detected in 70 quarters of 46 cows. Bacterial isolates were characterized at strain level by random amplified polymorphic DNA (RAPD) fingerprinting. Persistent infections were usually attributable to one strain, while recurrent infections could be caused by different strains. When multiple quarters of a cow were infected, infections were mostly caused by one strain. In each herd, multiple strains were identified yet one strain predominated. The majority of all infections were subclinical, and infections attributed to predominant strains were more chronic than infections attributed to other strains. Epidemiological and molecular data suggest infection from environmental sources with a variety of S. uberis strains as well as within-cow and between-cow transmission of a limited number of S. uberis strains, with possible transfer of bacteria via the milking machine.

We developed an immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA), using partial recombinant nucleoproteins (rNP) of Reston Ebola virus (EBO-R) and Zaire Ebola virus (EBO-Z). We examined the reaction of 10 sera from cynomolgus macaques naturally infected with EBO-R to each of the partial rNP in the IgG ELISA. All the sera reacted to the C-terminal halves of the rNP of both EBO-R and EBO-Z. Most of the sera reacted to the RΔC (amino acid (aa) 360–739), and RΔ6 (aa 451–551) and/or RΔ8 (aa 631–739) at a higher dilution than to the corresponding truncated rNPs of EBO-Z. The results indicate that this IgG ELISA is useful for detecting EBO-R specific antibody, and may have a potential to discriminate EBO-R infection from other subtypes.

Transmission of bovine herpesvirus 1 (BHV1) within and between herds was studied on the island of Ameland, The Netherlands. There were 50 herds with 3300 head of cattle on the island. Herds were divided into three groups: (1) only containing seronegative cattle, (2) containing seronegative cattle and vaccinated seropositive cattle, and (3) containing only vaccinated cattle. All 23 herds in groups 1 and 2 were monitored. Three major outbreaks of BHV1 infections were observed due to the introduction of infectious cattle. Another major outbreak was most likely induced by reactivation of latent BHV1 in seropositive cattle. The basic reproduction ratio within these herds was estimated at least 4. Only one of these outbreaks led to three secondary outbreaks in susceptible herds in which all cattle were seronegative. These outbreaks were most likely due to respectively, direct animal contact, human transmission, and aerogenic transmission. The basic reproduction ratio between herds in this study was estimated to be 0·6.

Mycobacterium avium subspecies paratuberculosis, the organism responsible for paratuberculosis in cattle and sheep has been found in wild rabbits (Oryctolagus cuniculus) in the east of Scotland. Few studies have investigated either the level of faecal contamination by rabbits on farms, or the potential infectivity of rabbit excreta. The rate of rabbit faecal contamination deposited and the numbers encountered were estimated for 21 fields on 4 farms with a paratuberculosis problem. 7357±2571 S.E.M. rabbit faecal pellets were deposited per hectare per day and up to 81000 pellets/ha (‘standing crop’) were encountered in October/November 1998. Where access to rabbits was restricted, the standing crop of faeces encountered fell to 22000 pellets/ha.

The prevalence of infection with M. a. paratuberculosis was assessed for 83 rabbits from the four farms. M. a. paratuberculosis was isolated from rabbits on all farms with an overall prevalence of 17%. Out of 17 rabbits from which urine was available, M. a. paratuberculosis was isolated from two – the first reported isolation from urine in wild rabbits. The mean number of colony-forming units per gram of infected rabbit faeces was 7·6×105±5·2×105.

A relative estimate of the input of M. a. paratuberculosis onto pasture, at the stocking levels found on the four farms, showed that sheep and cattle potentially contributed 4 and 125 times more organisms/ha per day respectively than rabbits. However, rabbits could still contribute millions of M. a. paratuberculosis organisms per ha per day. Existing rabbit control measures on farms may be inadequate in reducing the risk of transmission to livestock.

Livestock feed is susceptible to contamination from wildlife excreta during on farm storage. Pathogens associated with diseases such as paratuberculosis, salmonella and cryptosporidiosis are present in wild rodent and bird excreta. Feed stores on four farms in the east of Scotland were monitored monthly over the winter of 1998/9 to quantify the levels of wildlife faecal contamination. A mean of 79·9 rodent (95% confidence interval: 37·5–165·9) and 24·9 (14·3–41·7) bird faeces were deposited per m2 of stored feed per month. It was estimated that individual cattle and sheep could encounter 1626 and 814 wildlife faeces over the winter.

A model based on the numbers of infected faeces consumed per annum was used to estimate ‘infectious probabilities’ (Pinf) required to account for the reported prevalence of paratuberculosis, salmonella and cryptosporidiosis in sheep and cattle in the east of Scotland in 1998. Based on empirical data for input variables [the number of faeces encountered (Fe), the number ingested (Fi) and the prevalence of infection in wildlife species (Ip)], Pinf estimates ranged from 1·6×10−8 for cryptosporidiosis in sheep to 8·2×10−6 for paratuberculosis in cattle. The model suggested that ingestion of feed contaminated by wildlife faeces could account for the prevalence of all three diseases. Wildlife faecal contamination of stored feed should be given serious consideration as a potential source of infection to livestock.

We surveyed T serotypes and emm genotypes of Streptococcus pyogenes isolates from streptococcal toxic shock-like syndrome (TSLS) patients. T1 (emm1) remained dominant through 1992 to 2000, but the dominant T3 (emm3.1) strains from 1992 to 1995 disappeared during 1996–2000. Strains of several emm genotypes emerged during 1996–2000, indicating alterations in the prevalent strains causing TSLS.

Epidemiol. Infect. 128 (2002), 363–371

An outbreak of gastroenteritis in Osaka, Japan due toEscherichia coliserogroup O166[ratio ]H15 that had a coding gene for enteroaggregativeE. coliheat-stable enterotoxin 1 (EAST1)

Tables 1 and 2 were omitted