Outbreaks of soft tissue or skin infection due to non-tuberculous mycobacteria are reported frequently in scientific journals but in general the infection source in these outbreaks remains unknown. In Venezuela, in two distinct outbreaks, one after breast augmentation surgery and another after hydrolipoclasy therapy, 16 patients contracted a soft tissue infection due to Mycobacterium abscessus subsp. abscessus. Searching for the possible environmental infection sources in these outbreaks, initially the tap water (in the hydrolipoclasy therapy outbreak) and a surgical skin marker (in the breast implant surgery outbreak), were identified as the infection sources. Molecular typing of the strains with a variable number tandem repeat typing assay confirmed the tap water as the infection source but the molecular typing technique excluded the skin marker. We discuss the results and make a call for the implementation of stringent hygiene and disinfection guidelines for cosmetic procedures in Venezuela.

An IgM capture enzyme-linked immunosorbent assay for rubella-specific IgM was used to assess the avidity of specific IgM by comparing the results obtained with and without a mild protein denaturant in the washing fluid used after incubation of IgM with rubella haemagglutinating antigen. An avidity index (AI) was calculated with AIs < 50% considered to indicate low avidity. Sera from recent primary rubella, rubella reinfection and from patients persistently reactive for specific IgM were tested. Urea and diethylamine (DEA) were compared as the protein denaturants. Twenty-six of 28 sera from cases of primary rubella gave an AI < 50% with DEA, compared with 25 of 28 with urea. Seventeen of 20 sera from cases of reinfection gave an AI > 50% with DEA whereas only 14 of 20 had a similarly high avidity with urea. Eight of 10 sera from 4 cases of persistent specific IgM reactivity gave AIs > 50% with DEA, although this was reduced to 5 when urea was used. Thus a difference has been demonstrated between the avidity of specific IgM in primary infection from that demonstrated after a secondary antigenic challenge (reinfection). This may help in serologically distinguishing primary infection from reinfection.

A prospective survey was conducted in patients admitted to 11 randomly selected general practices and eight hospitals located in six provinces of Poland. For each patient meeting the international acute gastrointestinal infection (AGI) case definition criteria, information was collected on healthcare resources used. Antibacterial drug consumption was assessed using defined daily doses (DDD) and extrapolated to the national level using results from a parallel study of AGI incidence in the community. Additionally, a logistic multivariable model was fitted assessing determinants of antibacterial drug administration. Valid questionnaires were collected from 385 general practitioner (GP) consultations and 504 hospital admissions. Antibacterials for systemic use were prescribed during 60 (16%) GP consultations and 179 (36%) hospital admissions. The estimated societal AGI-related consumption of antibacterials amounted to 5·48 million DDD (95% uncertainty interval 1·56–14·12 million DDD). Antibacterial prescription was associated with work in large practices [adjusted odds ratio (aOR) 3·16] and hospital wards (aOR 2·87), compared to small general practices, referral for microbiological testing (aOR 2·88), presence of fever (aOR 2·50), presence of mucus or blood in stool (aOR 1·94), age >65 years vs. <5 years (aOR 1·88), and rural vs. urban residence (aOR 1·53). Despite the fact that antibacterials were prescribed to a minority of consulted AGI patients, their consumption in society was not negligible due to the high prevalence of AGI symptoms. Prescription of antibacterial drugs should be restricted to cases with specific indications, preferably following microbiological investigation of AGI aetiology. To achieve this, clear national recommendations should be widely disseminated to physicians, and included in medical training curricula.

The aim of this study was to determine the seroprevalence of Toxoplasma gondii infection in free-range chickens from Uberlândia, Minas Gerais state, Brazil, and characterize the genotypic and phenotypic features of two isolates of this parasite, considering the importance of these hosts in the epidemiology of toxoplasmosis. Serum samples from 108 free-range chickens were obtained from ten different districts, and submitted to the modified agglutination test (MAT) for the presence of anti-T. gondii antibodies, and brain and heart tissue samples from infected chickens were processed for mouse bioassay. An overall seroprevalence of 71·3% was found and antibody titres ranged from 16 to 4096. After confirmation of seropositivity by mouse bioassay, the determination of the T. gondii genotypes of two isolates was performed by PCR–RFLP, using primers for the following markers: SAG1, SAG2, SAG3, BTUB, GRA6, c22–8, c29–2, L358, PK1, new SAG2, Apico and CS3. These T. gondii isolates, designated TgChBrUD1and TgChBrUD2, were obtained from heart samples of free-range chickens. The TgChBrUD1 isolate belonged to ToxoDB PCR–RFLP genotype 11 and the TgChBrUD2 isolate belonged to ToxoDB PCR–RFLP genotype 6. Both isolates demonstrated high virulence in a rodent model, with the TgChBrUD1 isolate able to induce brain cysts, in accord with its pattern of multiplication rates in human fibroblast culture. Taken together, these results reveal high prevalence of T. gondii infection in free-range chickens throughout Uberlândia, indicating an important degree of oocyst environmental contamination and the existence of considerable risk for T. gondii transmission to humans by consumption of free-range chicken as a food source.

The Salmonella Bio-EnzaBead Screening Kit, in its modified form with both the MOPC 467 and the 6H4 antibodies, was used for the detection of salmonellas in naturally contaminated foods and animal feeding stuffs in parallel with a traditional cultural procedure.

Initial results showed an 82% agreement between the enzyme immunoassay (EIA) and cultural methods when using the criterion recommended by the manufacturer as a cut-off for all types of foods. By adjusting the cut-off for each type of food, the number of EIA positive, culture negative samples was reduced although the number of EIA negative, culture positive samples increased. The EIA may be more sensitive than the cultural methods as in many cases the EIA positive, culture negative results could be real positives which were not detected by the cultural methods.

The screening kit provides a simple and convenient method for the detection of salmonella in foods and feeds and a presumptive positive result can be reported within 48 h. The advantages and disadvantages of the method are discussed.

The aim of this study was to determine changes in the epidemiology of hepatitis A virus (HAV) infection in the Basque Country, Spain, and to evaluate their implications for vaccination strategies. A total of 1356 persons were enrolled in a study of the prevalence of anti-HAV in 2004 and compared with two previous studies (1986–1987 and 1992). The selection method and the characteristics of the population were similar in the three studies. A marked decline in the seroprevalence in all age groups (P<0·001) and in the incidence of cases/100000 inhabitants (from 38·0 in 1986–1988 to 2·9 in 2002–2004) were observed. The mean age of patients with hepatitis A increased from 17·7 years in 1986–1992 to 21·2 years in 1993–1998 and 25·3 years in 1999–2004 (P<0·001). Between 1997 and 2004, 20% of patients were hospitalized. The changes observed have occurred rapidly causing a change in the epidemiological pattern from middle-high endemicity (1986) to low endemicity (2004).

Because of recent reports of abortion in farmers' wives following infection with ovine strains of Chlamydia psittaci during pregnancy, the distribution of chlamydial antibodies was studied in rural populations in north-west England, where endemic chalamydial infection with abortion in common in sheep. Immunoperoxidase assays with C. treachomatis and ovine C. psittaci showed no significant differences in either the frequency or titres of antibodies between sheep farmers and other types of farmer or non-farming adults living in the same areas. The frequency and titers of antibodies in farmers' wives were no greater than in farmers, and were unrelated to their previous obstetric history or type of farming. Overall, 62/255 (24%) of this rural population had antibody detected by C. trachomatis antigen and only 30/255 (13%) detected by C.Psittaci antigen. The possible significance of these findings is discussed. This survey does not suggest that the risk of infection with C.psittaci is especially high in people working with sheep, but the complications following infection during pregnancy deserve the specific instructions that have been given to pregnant women to avoid exposure, especially during lambing, in farming and veterinary work.

Epidemiological evidence suggests that monoclonal antibody type 2 positive (MAB 2+) Legionella pneumophila serogroup 1 (LP1) more often causes disease than do MAB 2− isolates, and there is evidence that MAB 2− LP1 grow less well in cells than do MAB 2+ bacteria. We tested the intracellular growth rates of ten randomly selected MAB 2− LP1 isolates, by using guinea-pig alveolar macrophages, and human monocyte-derived macrophages. Save a low virulence control, all ten MAB 2− isolates grew as well in cells as a virulent MAB 2+ isolate. Heterogeneity of MAB 2− LP1 growth in cells exists, making poor intracellular growth an unlikely explanation for why MAB 2+ LP1 appear to cause disease more often.

Early prediction of the final size of any epidemic and in particular for Zika disease outbreaks can be useful for health authorities in order to plan the response to the outbreak. The Richards model is often been used to estimate epidemiological parameters for arboviral diseases based on the reported cumulative cases in single- and multi-wave outbreaks. However, other non-linear models can also fit the data as well. Typically, one follows the so called post selection estimation procedure, i.e., selects the best fitting model out of the set of candidate models and ignores the model uncertainty in both estimation and inference since these procedures are based on a single model. In this paper we focus on the estimation of the final size and the turning point of the epidemic and conduct a real-time prediction for the final size of the outbreak using several non-linear models in which these parameters are estimated via model averaging. The proposed method is applied to Zika outbreak data in four cities from Colombia, during the outbreak ocurred in 2015–2016.

An investigation has been described in which the complement fixing antibody titres of selected groups of the population have been correlated with the occurrence of epidemic and sporadic influenza and of other cases of respiratory disease which it was thought might be due to the virus of epidemic influenza.

During two non-epidemic seasons the influenza virus could not be isolated from cases of apparent influenza neither could any serological evidence be obtained of the existence of any form of respiratory disease caused by the virus.

With rare exceptions individual antibody titres either remain constant, or if they are high show a tendency to fall during non-epidemic times, and periodic investigations of sample groups each consisting of several hundred sera show a wave-like fluctuation in the titres of the population consisting of a sudden rise followed by a gradual fall, the former being an accompaniment of an epidemic. Such a wave-like fluctuation appears to be an indication of variations in the immunity of the population, and to be responsible in part, at least, for the occurrence of large influenza epidemics.

I wish to acknowledge the help received from all who took part in this investigation, and in particular to thank the students of the University Halls of Residence in Manchester, the numerous doctors who helped by supplying particulars of cases of influenza and to Dr R. W. Fairbrother who has given advice and maintained a constant interest throughout the investigation.

From January 1985 to May 1991, herald strains of influenza B virus were isolated in 1987 and 1989 in Japan. In both cases, influenza epidemics caused by the same type followed in the next winter season. The HA gene sequences of the influenza B viruses isolated in Japan from 1987–91, which covers two herald waves of influenza B viruses, were analysed and located on the phylogenetic tree for influenza B viruses after the B/Singapore/64 strain. Co-circulation of at least two evolutionary lineages of the HA genes existed for influenza B viruses in Japan during the period of this study. The herald viruses in one wave (1987) were genetically close to the winter isolates and were considered to be the parental viruses for the following influenza season, while in the other wave (1989) winter isolates belonged to another lineage on which one of the herald viruses was located, but they were genetically and antigenically different from the herald viruses.

The relationship between the serological findings for brucellosis and the epidemiological factors has been studied in veterinary surgeons in Northern Ireland. The anti-human globulin (Coombs) test and the complement-fixation test for brucella were used in two groups of veterinary surgeons, those self-employed and those employed by the Ministry of Agriculture.

Significant serological differences were found to exist between the two groups. Those in private practice showed changes related to age, cattle skin rash, reactions to S. 19 vaccine accidents and symptoms suggestive of brucellosis in the past or the last year. But those working for the Ministry only showed titre changes related to the length of their private practice experience before joining the Ministry. In neither group was there a relationship between serological findings and the type of milk drunk or any particular group of symptoms suggestive of brucellosis.

The findings indicate that high titres to brucella by the Coombs and complement-fixation test can occur in people repeatedly exposed to infection at work. Titres which would be of diagnostic importance in the rest of the population may be of little diagnostic significance even when they are as high as 160 Coombs and 128 complement fixation.

The course of experimental infection in groups of 6-month-old castrated lambs with field isolates of Mycoplasma agalactiae from France was followed culturally and serologically for 7 months. Infection with an ovine field isolate following inoculation by different routes and contact exposure was compared with that caused similarly by a caprine field isolate. The prolonged infections produced were symptomless apart from limited arthritis in one animal inoculated with the isolate from sheep and increased lachrymation in another associated with the goat isolate. The ovine isolate was more virulent in that ante- and post-mortem recoveries of the organism were more consistent and the serological responses more pronounced. Serological responses varied between animals and between strain infections, and the results of the film inhibition test were more consistent than those of the complement fixation test. The limitations of both these tests for detecting carrier infections are discussed.

Newborns often present with skin conditions ranging from transient benign to severe. An occasional cause of neonatal exanthemic rash is infection due to Gram-positive bacteria, but Gram-negative infection is uncommon. We describe an outbreak of sepsis in 10 neonates over a 2-week period, caused by Klebsiella pneumoniae in a level III neonatal intensive care unit (NICU). Seven babies developed an exanthematous maculopapular rash. Molecular analysis by pulsed-field gel electrophoresis showed that all the babies with rash were infected by a single strain of K. pneumoniae which was distinct from the strain recovered from babies without rash.

Understanding endemic infectious disease risk factors through traditional epidemiological tools is challenging. Population-based case–control studies are costly and time-consuming. A case–case analyses using surveillance data addresses these limitations by using resources more efficiently. We conducted a case–case analyses using routine surveillance data reported by 16 U.S. states (2005–2015), wherein reported cases of salmonellosis were used as a comparison group to identify exposure associations with reported cases of cryptosporidiosis and giardiasis. Odds ratios adjusted for age and reporting state (aOR) and 95% confidence intervals (95% CI) were calculated. A total of 10 704 cryptosporidiosis cases, 17 544 giardiasis cases, and 106 351 salmonellosis cases were included in this analyses. When compared with cases of salmonellosis, exposure to treated recreational water (aOR 4.7, 95% CI 4.3–5.0) and livestock (aOR: 3.2; 95% CI: 2.9–3.5) were significantly associated with cryptosporidiosis and exposure to untreated drinking (aOR 4.1, 95% CI 3.6–4.7) and recreational water (aOR 4.1, 95% CI 3.7–4.5) were associated with giardiasis. Our analyses shows that routine surveillance data with standardised exposure information can be used to identify associations of interest for cryptosporidiosis and giardiasis.

African horse sickness (AHS) and equine encephalosis (EE) viruses are endemic to southern Africa. AHS virus causes severe epidemics when introduced to naive equine populations, resulting in severe restrictions on the movement of equines between AHS-positive and negative countries. Recent zoning of South Africa has created an AHS-free zone to facilitate equine movement, but the transmission dynamics of these viruses are not fully understood. Here, we present further analyses of serosurveys of donkeys in South Africa conducted in 1983–5 and in 1993–5. Age-prevalence data are used to derive estimates of the force of infection, λ. For both viruses, λ was highest in the northeastern part of the country and declined towards the southwest. In most of the country, EE virus had a higher transmission rate than AHS. The force of infection increased for EE virus between 1985 and 1993, but decreased for AHS virus. Both viruses showed high levels of variation in transmission between districts within the same province, particularly in areas of intermediate transmission. These data emphasize the focal nature of these viruses, and indicate areas where further data will assist in understanding the geographical variation in transmission.

Antimicrobial resistance (AMR) in Neisseria gonorrhoeae compromises patient treatment and disease control. Epidemiologically based surveillance of AMR in gonococci is needed to optimize standard treatment regimens. Validation of AMR surveillance data depends on external quality assurance schemes (EQAS). AMR surveillance data quality in India during 2001–2007 was assessed by participants testing panels of reference strains and repeated re-challenge with identical controls, accompanied by educative feedback. Overall, correct results were obtained for 944 (82%) of 1030 tests performed for five ‘core’ antibiotics. Aggregated error rates decreased from 33% (123 tests) in 2001 to 4·4% (180 tests) in 2007 with improvements in individual laboratory performance. Cephalosporin test results produced high error rates without improvement. Reference centre and network laboratory collaboration produced marked improvements in test performance through annual EQAS integrating proficiency testing and participant education. More frequent EQAS cycles would assist this process. These experiences may be applicable in similar settings elsewhere.

1. Standard Bact. coli cultures have been heated at 51° C. in phosphate buffered media having pH values ranging from 2·8 to 8·8, and survivor curves obtained.

2. Except at pH 3·9, the first continuous decline in viable numbers was followed by the establishment of a small fluctuating residual population which was apparently permanent.

3. The colony counts showed a moderate excess of unduly high values of x2, the bulk of which were encountered when the mortality was between 95 and 99·999%.

4. Prolonged incubation of the plates led to increased colony counts, but the rise was confined to the active disinfection phase. It occurred chiefly in the 95–99·999% mortality range and was moderate in degree. The x2 values were little affected.

5. The log survivors-time graphs of the disinfection phase were convex in type but approached linearity in the faster reactions. The logarithmic death-rate became maximal at about 90 % mortality and thereafter remained constant, though under the more acid conditions a somewhat lower rate was maintained. At pH 7·0 and 6·4 the curves were exceptionally straight.

6. Standardization of all the curves revealed a continuous change in shape with pH but, nevertheless, they could be placed in three closely knit overlapping groups which were best revealed by the variation in maximum death-rate.

7. The 50–99·99% mortality times were obtained either from the calculated regressions of log survivors on time over the linear portions of the curves or, outside that range, from the freehand curves. Maximum survival at all mortality levels occurred at about pH 6·5–6·6, i.e. close to the neutral point of pure water at 51° C. On both sides of this point sensitivity increased regularly but was abnormally high at pH 7·0 and 6·4.

8. Within these zones of abnormally high sensitivity the assessment of the effect of a given change in pH varied in amount and direction according to the mortality level chosen.

9. The enhanced resistance of a culture regenerated from the survivors of a disinfection at 51° C. and pH 7.0, as previously reported, could possibly have been largely due to a small increase in acidity but not to a slight shift towards alkalinity.

We used the clustered lot quality assurance sampling (clustered-LQAS) technique to identify districts with low immunization coverage and guide mop-up actions during the last 4 days of a combined oral polio vaccine (OPV) and yellow fever (YF) vaccination campaign conducted in Cameroon in May 2009. We monitored 17 pre-selected districts at risk for low coverage. We designed LQAS plans to reject districts with YF vaccination coverage <90% and with OPV coverage <95%. In each lot the sample size was 50 (five clusters of 10) with decision values of 3 for assessing OPV and 7 for YF coverage. We ‘rejected’ 10 districts for low YF coverage and 14 for low OPV coverage. Hence we recommended a 2-day extension of the campaign. Clustered-LQAS proved to be useful in guiding the campaign vaccination strategy before the completion of the operations.

Human cytomegalovirus (CMV) is a common herpesvirus establishing lifelong persisting infection, which has been implicated in immunosenescence and mortality in the elderly. Little is known about how and when susceptibility to CMV infection is determined. We measured CMV seroprevalence in two genetically informative cohorts. From the Leiden Longevity Study (LLS) we selected long-lived sib-pairs (n=844) and their middle-aged offspring and the offspring's partners (n=1452). From the Longitudinal Study of Aging Danish Twins (LSADT) 604 (302 pairs) same-sex monozygotic (MZ) and dizygotic (DZ) twins aged 73–94 years were included (n=302 pairs). Offspring of the long-lived LLS participants had significantly lower seroprevalence of CMV compared to their partners (offspring: 42% vs. partners: 51%, P=0·003). Of 372 offspring living with a CMV-positive partner, only 58% were infected. The corresponding number for partners was 71% (P<0·001). In the LSADT, MZ and DZ twins had high and similar CMV-positive concordance rates (MZ: 90% vs. DZ: 88%, P=0·51) suggesting that shared family environment accounts for the similarity within twin pairs. Our findings suggest that susceptibility to CMV infection – even under continuous within-partnership exposure – appears to be more strongly influenced by early-life environment than by genetic factors and adult environment.