The relationship, in 539 individuals infected with the human immunodeficiency virus (HIV), between two prognostic markers, the CD4 count and beta-2-microglobulin (B2M), and the development of the acquired immunodeficiency syndrome (AIDS) and death was investigated. Cox proportional hazards models were used to determine the risk of AIDS or death. In a multivariate model which adjusted for demographic factors and treatment, the most recent measurements of B2M (relative hazard (RH) 1·37 per g/l higher) and CD4 count (RH 2·17 per log-unit lower) were both significantly associated with the development of AIDS. Similarly, in a multivariate model which additionally adjusted for the development of AIDS as a time dependant covariate, there was a strong relationship with risk of death for the most recent measurements of B2M (RH 1·34 per g/l higher), and CD4 lymphocyte count (RH 1·91 per log-unit lower). A difference in the level of B2M could be used among patients with similar CD4 counts as an indicator of increased risk of progression to AIDS or death. Using the most recent values of these markers provides a better estimate of the risk of AIDS or death, compared to the more common method of analysis, where baseline values of the markers are used.

Selenite F broth and a modified Muller—Kauffmann tetrathionate broth were investigated using sewage-polluted natural water as inocula. The modification of the tetrathionate medium was necessary as commercial alternatives would not allow multiplication of small numbers of salmonellas.

The wide range of molar concentrations in different tetrathionate broths was emphasized.

Selenite F broth was more efficient than Muller—Kauffmann tetrathionate broth, in our hands, with the material tested. Direct inoculation of the enrichment media was used.

Each of the two media examined had a bias towards selection of certain sero types. If possible, both enrichment broths should be used to obtain maximum information.

Restriction patterns obtained with EcoRI and Southern hybridization were used for the differentiation of tetracycline-resistant (Tetr) R plasmids in enterobaemorrhagic Escherichia coli (EHEC) O157[ratio ]H7 isolates from a mass outbreak at a kindergarten in Obihiro-City, Hokkaido, Japan, 1996. Two kinds of Tetr R plasmids of 50 and 95 kb were detected. The 50-kb plasmids were identical to each other, while the 93-kb plasmids were of three types that were very similar to each other. The tet genes of both 50- and 95-kb R plasmids were 100% identical to the tet gene of pSC101 and all plasmids hybridized to a probe for tet. Because food-origin O157 strains were sensitive to tetracycline, we concluded that such Tetr R-plasmids might transfer to drug-sensitive O157 strains in the infected individuals.

The colour-change and lead acetate tests for fermentation of d–, l–and m–tartaric acids and citric acid used in the Kristensen scheme for biotyping Salmonella typhimurium were found to be unreliable because, whatever the conditions of culture, they gave different results in replicate tests of the same strains. Many genotypically non-fermenting strains gave inconsistent reactions due to the emergence of fermenting mutant bacilli in some of their test cultures. No reliable test was found for the fermentation of citric acid.

A ‘turbidity’ test was found to give consistent and reliable results with the three tartaric acid isomers. It demonstrated fermentation by the significantly greater amount of growth obtained in a 24 hr. culture in Oxoid peptone water with added isomer than in a control culture without isomer. Lewis & Stocker's (1971) plate-inhibition test for fermentation of m–tartrate, which identifies m–tartrate-negative strains because m–tartrate inhibits their growth on citrate- or glycerol-containing minimal medium, was found to be as reliable as, and easier to read than, the turbidity test.

Use of the turbidity test for d–and l–tartrates and the plate-inhibition test for m–tartrate in biotyping 1435 strains of S. typhimurium showed that many strains had previously been mistyped by the lead acetate test and distinguished 16 new biotypes in addition to the 22 biotypes already recognized.

The transmission of human metapneumovirus (hMPV) among family members is not well understood. We identified 15 families in which multiple members were diagnosed with hMPV infection by real-time PCR in 2008 and 2010. Index patients ranged in age from 2 years to 11 years (median 5 years), and all 15 index cases were children who attended primary school, kindergarten, or nursery school. Contact patients ranged in age from 2 months to 46 years (median 6 years). Excluding five adult cases, contact patients were significantly younger than index patients (P = 0·0389). Of the 12 contact children, seven (58%) were infants who were taken care of at home. The serial interval between the onset of symptoms in an index patient and the onset of symptoms in a contact patient was estimated to be 5 days. These results suggest that the control of school-based outbreaks is important for preventing hMPV infection in infants.

Human rhinoviruses (HRVs) are widespread respiratory pathogens and a major cause of acute respiratory tract infections. The aim of this study was to investigate the molecular epidemiology of rhinovirus infections in children in Cyprus over three consecutive winter seasons. From a total of 116 rhinovirus-positive samples, 68 were sequenced in the 5’-UTR and VP4/VP2 regions. Thirty-six (52·9%) samples were identified as HRV-A and 27 (39·7%) as HRV-C, with only five (7·4%) samples belonging to the HRV-B species. Of these, a total of 46 different genotypes were identified. In the VP2/VP4 phylogenetic tree all strains clustered in three different well-defined clades, whereas the 5’-UTR tree exhibited clades with a mixed clustering of HRV-A and HRV-C strains reflecting the evolutionary history of recombination between HRV-A and HRV-C that has been observed previously. In summary, a high intra- and inter-season diversity of HRV types was observed. Despite its geographical isolation the frequency of HRV species in Cyprus is comparable to that reported in other regions of the world supporting the concept of an unrestricted global circulation. This study assesses, for the first time, the epidemiology of rhinovirus infections in Cypriot children and will be helpful to clinicians and researchers interested in the treatment and control of viral respiratory tract infections.

Ljungan virus (LV) is a picornavirus related to human parechoviruses (HPeV). The virus has been found in bank voles (Myodes glareolus) and several other rodent species, and suggested to have zoonotic potential. Thus far, seroepidemiological data on LV infections in humans are scarce. In this study, we aimed to characterize the demographic and geographical distribution of LV-reactive antibodies in Finland, and to investigate its occurrence in patients suspected of having a rodent-borne disease, nephropathia epidemica (NE) caused by Puumala hantavirus (PUUV). Using an immunofluorescence assay (LV strain 145SLG), we screened human sera (n = 1378) and found LV-reactive antibodies in 36% of samples. The probability of possessing LV-reactive antibodies peaked at age of 14 years, suggesting that most infections occur in childhood. The prevalence of LV-reactive antibodies was significantly higher in the urbanized area surrounding Helsinki than in more rural Central Finland. These findings are uncharacteristic of a rodent-borne pathogen, and therefore we consider human-to-human transmission of one or several Ljungan-like viruses as a likely cause for most of the observed antibody responses.

The results of typing all group A streptococci isolated in one laboratory in 5 years were reviewed to see if the collected information showed epidemiological patterns. The great majority of the 5858 streptococci typed came from patients seen in general practice: 72% from throat swabs and 11 % from skin lesions. Eight types, M types 1, 2, 3, 4, 6, 12, 22 and type 28 R accounted for 65% of strains. These eight types had different patterns: types 2 and 6 caused small circumscribed outbreaks and were uncommon between epidemics; types 3, 4 and 12 caused larger, wider epidemics, whereas types 1, 22 and 28 R had a more stable pattern. Type 4 was more commonly resistant to tetracycline than most other types, a finding which affected the apparent incidence of tetracycline resistance in group A streptococci. Streptococci from superficial sites were more likely to have serum opacity factor and to lack a detectable M-antigen than strains isolated from the throat. Routine typing of streptococci helped to detect outbreaks of infection in special groups. It is concluded that regular streptococcal typing should be continued in some places.

A number of outbreaks and pseudo-outbreaks have been associated with contaminated rinse water in endoscope washer-disinfectors. Health Technical Memorandum 2030 specifies that final rinse water should be ‘bacteria-free’. In this study, results of rinse-water testing from 20 endoscopy units were reviewed over a 4-month period. Over 60% of samples were of an unsatisfactory quality (i.e. not bacteria-free) and none of the endoscopy units consistently achieved sterile water throughout the study period. Poor microbiology results caused anxiety to endoscopy staff and infection control teams who had to decide whether or not to take washer-disinfectors out of use, possibly resulting in delays to medical procedures. There was no common policy on how to react to poor results, with staff at each unit developing their own action levels. Here, it is suggested that future guidelines would be of more practical use if they specified a series of action levels of increasing severity based on the bacterial count in a water sample.

Since the implementation of Streptococcus pneumoniae (SPn) conjugate vaccination (PCV), non-vaccine types have prevailed in invasive pneumococcal disease (IPD), and an increase in Staphylococcus aureus (SA) burden has been suggested. Here, we assess the epidemiology of SA and SPn nasal carriage in 620 children at day-care centres; 141 of these children had received 1–4 PCV7 doses. A higher vaccine dosage was associated with non-vaccine-type SPn carriage. Of all SPn isolates, 45% were PCV7 types, 1% were additional PCV10 types and 22% were the three additional PCV13 types. SA carriage was inversely associated with vaccine-type SPn carriage. SPn serotype 19A showed higher SA co-carriage rates compared to other SPn serotypes. PCV7 implementation does not prevent children from being part of the IPD-related SPn transmission chain. These results contribute to the monitoring of SA- and SPn-related disease and add to the debate on the current national vaccination policy that recently included a change from PCV7 to PCV10.

Between 2007–2008 and 2010–2012, 870 organ samples were collected from wild boars in 16 Transylvanian counties. Anaplasma phagocytophilum DNA was identified using a nested PCR protocol that amplifies a fragment of the 16S rRNA gene. Prevalence was compared between sampling periods and counties using Fisher's exact test. In total, 39 (4·48%) samples tested positive, with significantly higher values recorded in the second period, caused by an increased infection rate in boars from Sibiu county. Positive cases tended to concentrate in the central part of the country. During the second sampling period, A. phagocytophilum was detected in two additional counties, suggesting a spatial spreading of the pathogen. The results confirm that Transylvanian wild boars are naturally infected with A. phagocytophilum, thus raising awarness concerning a potential zoonotic cycle. This is the first study to evaluate spatial and temporal variations of A. phagocytophilum distribution in wild boar populations from Transylvania.

One of the most striking points in the pathology of Bacterial Dysentery is the fact that while the bacilli are found regularly in the mesenteric glands, they are not found in the spleen or other organs, and do not occur in the blood, urine, or milk. In this respect Lentz (p. 320) points out that the disease differs markedly from the septicaemic diseases, such as typhoid, and that it must be regarded as a local infection of the intestinal mucous membrane and corresponding lymphatic glands by the bacillus, the toxin alone passing into the circulation and giving rise to the typical clinical picture, which, as in the case of cholera, gives the impression of a severe poisoning or toxaemia.

The baseliiie susceptibility of the lesser bandicoot rat, Bandicota bengalensis, from Rangoon, Burma, to five anticoagulant rodenticides was established with no-choice feeding in the laboratory. The susceptibility of lesser bandicoots to the several poisons (brodifacoum, difenacoum, diphacinone, coumatetralyl, and warfarin) was such that they were offered at a 0·001 % concentration. B. bengalensis was most susceptible to brodifacoum, and in descending order, difenacoum, coumatetralyl, diphacinone and warfarin. In comparison with Rattus norvegicus on warfarin at 0·005 %, B. bengalensis proved more susceptible. Feeding tests at 0·005 % concentration indicated that a 1-day feeding on broclifacoum and difenacoum would result in complete mortality, whereas coumatetralyl and warfarin would require 4 days feeding to a 100 % kill. Brodifacoum and difenacoum are recommended at 0·002–0·005 % bait concentrations and coumatetralyl at 0 001 % concentrations for the control of B. bengalensis in the field in Rangoon. The use of any anticoagulant material in rat control should be alternated with acute toxicants to retard the possible development of anticoagulant resistance.

Understanding the epidemiology of current health threats to deployed U.S. troops is important for medical assessment and planning. As part of a 2004 study among U.S. military personnel deployed to Al Asad Air Base, in the western Anbar Province of Iraq, over 500 subjects were enrolled, provided a blood specimen, and completed a questionnaire regarding history of febrile illness during this deployment (average ∼4 months in country). This mid-deployment serum was compared to pre-deployment samples (collected ∼3 months prior to deployment) and evaluated for seroconversion to a select panel of regional arboviral pathogens. At least one episode of febrile illness was reported in 84/504 (17%) of the troops surveyed. Seroconversion was documented in nine (2%) of deployed forces tested, with no association to febrile illness. Self-reported febrile illness was uncommon although often debilitating, and the risk of illness due to arbovirus infections was relatively low.

In July 2014, an outbreak of gastroenteritis occurred among visitors to lakes in Tampere, Finland. We conducted a retrospective cohort study using an internet-based survey, solicited by public announcement, to identify source of infection and to implement control measures. Of 1453 persons enrolled in the study, 244 met the case definition (attack rate, 17%). In the pooled univariate analysis, risk factors for gastroenteritis included getting water in the mouth while swimming (Risk ratio (RR) 3.32; 95% Confidence interval (CI), 2.36–4.68) and playing on the wet sand at the beach (RR 1.90; 95% CI 1.50–2.41). In a multivariable analysis (logistic regression), the source of the infection was likely at two lakes (lake A Odds ratio (OR) 1.66; 95% CI 1.15–2.39 and lake B, OR 2.35; 95% CI 1.49–3.72). Norovirus (NoV) was found in 19 stool samples. All water samples from implicated beaches had acceptable values of fecal indicator bacteria and were negative for NoV. The likely source of the outbreak was lake-water contaminated with NoV at two popular lakes. Closure of swimming beaches, advice on hygienic precautions and rapid outbreak alerts were efficient in controlling the outbreak. Results suggest a need for new indicators of water quality and development of evidence-based recommendations regarding timing of safe reopen of recreational water venues associated with outbreaks.

A total of 1452 cases of typhoid fever was notified in Singapore from 1980–9. The morbidity rates of indigenous cases showed a steady decline from 5.9 per 100000 population in 1980 to 1.2 per 100000 population in 1989. The mean case fatality was 0.8%. Children, adolescents and young adults were most susceptible to typhoid fever. There was no significant difference in morbidity rates between the major ethnic groups. The vast majority of indigenous cases were sporadic while outbreaks accounted for almost one third of them. Food was the main vehicle of transmission. The commonest indigenous phage types were B1, D1 and A. Antimicrobial resistance was infrequently seen. The proportion of imported cases rose from 32% in 1980 to 72% in 1989. Almost half (48.5%) of all imported cases were local residents who contracted typhoid fever while travelling in endemic countries. As imported cases assume greater importance in the epidemiology of typhoid fever in Singapore, further drop in typhoid fever incidence would require reduction of travel-related cases through greater awareness of food hygiene and effective vaccination.

The incidence of nosocomial candidaemia was evaluated in a retrospective study in a Turkish tertiary-care hospital. Over a 12-year period (1996–2007), a total of 743 episodes of candidaemia occurred in 743 patients, accounting for an average incidence of 1·9 episodes/1000 admissions and 2·9 episodes/10 000 patient-days per year. The annual incidence was almost constant during the study period except for 1996 when it was significantly higher in comparison with other years (P<0·05). The most common species isolated was Candida albicans (45%), followed by C. parapsilosis (26%), C. tropicalis (7%), C. krusei (7%), and C. glabrata (3·5%). A significant increase in C. albicans isolates causing candidaemia linked to a decrease in C. parapsilosis isolates in adult patients and C. krusei isolates in children was found between the two 6-year study periods. This trend reflects improved infection control at Uludağ University Hospital. Ninety percent of isolates were susceptible to fluconazole (⩽8 μg/ml) and resistance was found only in C. glabrata and C. parapsilosis isolates. Regular local surveillance of Candida spp. is important in order to develop empirical treatment protocols to reduce the incidence and mortality of candidaemia.

To estimate incidence and completeness of notification of Legionnaires' disease (LD) in The Netherlands in 2000 and 2001, we performed a capture–recapture analysis using three registers: Notifications, Laboratory results and Hospital admissions. After record-linkage, 373 of the 780 LD patients identified were notified. Ascertained under-notification was 52·2%. Because of expected and observed regional differences in the incidence rate of LD, alternatively to conventional log-linear capture–recapture models, a covariate (region) capture–recapture model, not previously used for estimating infectious disease incidence, was specified and estimated 886 LD patients (95% confidence interval 827–1022). Estimated under-notification was 57·9%. Notified, ascertained and estimated average annual incidence rates of LD were 1·15, 2·42 and 2·77/100 000 inhabitants respectively, with the highest incidence in the southern region of The Netherlands. Covariate capture–recapture analysis acknowledging regional differences of LD incidence appears to reduce bias in the estimated national incidence rate.

Airborne contamination in an operating suite was studied with a slit sampler, settle plates and a light-scattering particle counter. In conventional operating rooms there was a significant difference between the empty rooms and rooms in use; the mean total bacterial count by a slit sampler changed from 1·1 in empty to 42·5 c.f.u./m3 in use (39 times increase), the settle plates count changed from 1·5 to 17·4 c.f.u./m2/min (12 times increase), and the mean total particle count changed from 56·9 to 546·7/1 (10 times increase) respectively. The increase was caused mainly by persons present in the room.

Another difference was found between zones in the operating suite; the bacterial count in the clean area doubled in the semi-clean area and further doubled in the dirty area in slit sampler count as well as settle plates count, and particle count in the clean area increased by 14 times in the semi-clean and dirty areas. This difference resulted from the different quality of the ventilating system.

Air cleanliness of operating rooms in use by persons present in the room dropped to a level between the clean and the semi-clean area in spite of the high quality of the ventilating system.

Bacterial species identified were mostly coagulase negative staphylococci and micrococci.

Our study indicates that reduction of airborne contamination in an operating suite is accomplished by the combination of an efficient ventilating system and the restriction of the number of persons present in the room.

We estimated the extent of undiagnosed hepatitis C virus (HCV) infection in injecting drug users (IDUs) in Scotland. We used record-linkage to determine HCV diagnosis status for 41 062 current/former IDUs attending drug treatment and support services between 1 April 1995 and 31 March 2006; the extent of undiagnosed HCV infection was estimated by comparing the number HCV-diagnosed to the number HCV-infected (estimated from an unlinked anonymous testing survey of 2141 current/former IDUs). In all, 9145 IDUs (22%) were diagnosed HCV antibody-positive since first attendance at drug services (diagnosis rate of 33·6/1000 person-years, 95% CI 32·7–34·4). By 31 March 2006, of the 19 632 current/former IDUs who had attended drug services and were determined to be living with HCV, an estimated 58% (95% CI 45–62) had not been HCV-diagnosed. It is essential that the deployment of resources for identifying at-risk IDUs with a view to offering antiviral therapy is guided by evidence.