Influence of socio-economic status on Shiga toxin-producing Escherichia coli (STEC) infection incidence, risk factors and clinical features.

Shiga toxin-producing Escherichia coli (STEC) infection can cause serious illness including haemolytic uraemic syndrome. The role of socio-economic status (SES) in differential clinical presentation and exposure to potential risk factors amongst STEC cases has not previously been reported in England. We conducted an observational study using a dataset of all STEC cases identified in England, 2010-2015. Odds ratios for clinical characteristics of cases and foodborne, waterborne and environmental risk factors were estimated using logistic regression, stratified by SES, adjusting for baseline demographic factors. Incidence was higher in the highest SES group compared to the lowest (RR 1.54, 95% CI 1.19-2.00). Odds of Accident and Emergency attendance (OR 1.35, 95% CI 1.10-1.75) and hospitalisation (OR 1.71, 95% CI 1.36-2.15) because of illness were higher in the most disadvantaged compared to the least, suggesting potential lower ascertainment of milder cases or delayed care-seeking behaviour in disadvantaged groups. Advantaged individuals were significantly more likely to report salad/fruit/vegetable/herb consumption (OR 1.59, 95% CI 1.16-2.17), non-UK or UK travel (OR 1.76, 95% CI 1.40-2.27; OR 1.85, 95% CI 1.35-2.56) and environmental exposures (walking in a paddock, OR 1.82, 95% CI 1.22-2.70; soil contact, OR 1.52, 95% CI 2.13-1.09) suggesting other unmeasured risks, such as person-to-person transmission, could be more important in the most disadvantaged group.

Estimating the incubation period of acute Q fever, a systematic review.

Estimates of the incubation period for Q fever vary substantially between different reviews and expert advice documents. We systematically reviewed and quality appraised the literature to provide an evidence-based estimate of the incubation period of the Q fever by the aerosolised infection route. Medline (OVIDSP) and EMBASE were searched with the search limited to human studies and English language. Eligible studies included persons with symptomatic, acute Q fever, and defined exposure to Coxiella burnetti. After review of 7115 titles and abstracts, 320 records were screened at full-text level. Of these, 23 studies contained potentially useful data and were quality assessed, with eight studies (with 403 individual cases where the derivation of incubation period was possible) being of sufficient quality and providing individual-level data to produce a pooled summary. We found a median incubation period of 18 days, with 95% of cases expected to occur between 7 and 32 days after exposure.

A systematic review and meta-analysis on the incubation period of Campylobacteriosis.

Accurate knowledge of pathogen incubation period is essential to inform public health policies and implement interventions that contribute to the reduction of burden of disease. The incubation period distribution of campylobacteriosis is currently unknown with several sources reporting different times. Variation in the distribution could be expected due to host, transmission vehicle, and organism characteristics, however, the extent of this variation and influencing factors are unclear. The authors have undertaken a systematic review of published literature of outbreak studies with well-defined point source exposures and human experimental studies to estimate the distribution of incubation period and also identify and explain the variation in the distribution between studies. We tested for heterogeneity using I 2 and Kolmogorov-Smirnov tests, regressed incubation period against possible explanatory factors, and used hierarchical clustering analysis to define subgroups of studies without evidence of heterogeneity. The mean incubation period of subgroups ranged from 2·5 to 4·3 days. We observed variation in the distribution of incubation period between studies that was not due to chance. A significant association between the mean incubation period and age distribution was observed with outbreaks involving only children reporting an incubation of 1·29 days longer when compared with outbreaks involving other age groups.

Interventions to increase influenza vaccination rates in children with high-risk conditions--a systematic review.

BACKGROUND: Influenza is a common cause of morbidity and mortality, especially among the elderly and those with certain chronic diseases. Annual influenza vaccination is recommended for individuals in at-risk groups, but rates of vaccination are particularly low in children with high-risk conditions (HRCs). OBJECTIVE: To conduct a systematic review of studies that have examined interventions aimed at improving influenza vaccination in children with HRCs. METHODS: Two databases - PubMed and SCOPUS - were searched (with no time or language restrictions) using a combination of keywords - Influenza AND vaccination OR immunization OR children AND asthma OR malignancy OR high-risk AND reminder. Duplicates were removed, and abstracts of relevant articles were screened using specific inclusion/exclusion criteria. Thirteen articles were selected, and five additional studies were identified following a review of the reference lists of the initial thirteen articles, bringing the total number to eighteen. RESULTS: Most studies were conducted in the United States. Among the 18 studies, there was one systematic review of a specific intervention in asthmatic children, seven randomized controlled trials (RCTs), six before-and-after studies, one non-randomized controlled trial, one retrospective cohort study, one quasi-experimental post-test study, and one letter to editors. Interventions reported include multi-component strategies, letter reminders, telephone recall, letters plus telephone calls, an asthma education tool and year-round scheduling for influenza vaccination, amongst others. CONCLUSION: There is good evidence that reminder letters will improve influenza vaccination uptake in children with HRCs, but the evidence that telephone recall or a combination of letter reminder and telephone recall will improve uptake is weak. It is not known if multiple reminder letters are more effective than single letters or if multi-component strategies are more effective than single or dual component strategies. There is a need for further research of these interventions, possibly outside the United States.

Changing socioeconomic risk factors for invasive H. influenzae disease after the introduction of conjugate vaccine.

OBJECTIVES: To determine socioeconomic risk factors for invasive Haemophilus influenzae (HI) disease before and after the introduction of HI type b (Hib) conjugate vaccine in the West Midlands, UK. METHODS: Study population consisted of children aged <5 years with laboratory confirmed invasive disease. Linear associations between disease rates and socioeconomic variables were examined 2-years before and 2-years after the introduction of conjugate vaccine. RESULTS: Pre-vaccine there were no trends in disease incidence. Post-vaccine there was an absolute reduction in disease incidence and significant disease differentials between affluent and deprived populations were identified for non-owner-occupancy (P=0.032) and car access (P=0.049). CONCLUSIONS: Our results suggest that changes in socioeconomic risk factor for invasive HI occurred after the introduction of conjugate vaccine. This may have implications for future immunisation strategies.

Ecological analysis of ethnic differences in relation between tuberculosis and poverty.

OBJECTIVE: To examine the effect of ethnicity on the relation between tuberculosis and deprivation. DESIGN: Retrospective ecological study comparing incidence of tuberculosis in white and south Asian residents of the 39 electoral wards in Birmingham with ethnic specific indices of deprivation. SETTING: Birmingham, 1989-93. SUBJECTS: 1516 notified cases of tuberculosis. MAIN OUTCOME MEASURES: Rates of tuberculosis and measures of deprivation. RESULTS: Univariate analysis showed significant associations of tuberculosis rates for the whole population with several indices of deprivation (P<0.01) and with the proportion of the population of south Asian origin (P<0.01). All deprivation covariates were positively associated with each other but on multiple regression, higher level of overcrowding was independently associated with tuberculosis rates. For the white population, overcrowding was associated with tuberculosis rates independently of other variables (P=0.0036). No relation with deprivation was found for the south Asian population in either single or multivariable analyses. CONCLUSIONS: Poverty is significantly associated with tuberculosis in the white population, but no such relation exists for those of Asian ethnicity. These findings suggest that causal factors, and therefore potential interventions, will also differ by ethnic group.

A case-control study of elderly patients with acute respiratory illness: effect of influenza vaccination on admission to hospital in winter 2003-2004.

Every winter, hospitals face a large increase in emergency respiratory admissions in elderly people. A case-control study was undertaken to assess the effect of routine influenza vaccine in preventing such admissions among a cohort of UK elderly presenting with acute respiratory illness during winter 2003-2004. 157 hospitalised cases and 639 controls (matched for age, sex and week of consultation) were interviewed. In a winter typical of levels of circulating influenza in recent years, influenza vaccine did not show a protective effect on emergency respiratory admissions overall (adjusted OR 1.2 (95%CI 0.8, 1.9). Policy makers should not rely solely on influenza vaccine routinely having a large effect on winter pressures, and should focus on additional preventive strategies.

A survey of the implementation of health service guidelines on arrangements for infection control in health trusts in the West Midlands.

A good hospital infection control programme can reduce hospital acquired infection, which causes considerable morbidity, mortality, and cost. NHS trusts in the West Midlands were surveyed to assess progress in implementing national infection control guidelines. All 25 acute trusts replied but only 13 of 21 trusts for the community or for mental health (MH). Twenty-four acute trusts had access to an infection control nurse (ICN), but ICNs were responsible for an average of 520 acute beds, twice as many as usually recommended. Seven (of 13) community/MH trusts had only informal arrangements for access to an ICN. Six acute trusts had no formal arrangements for covering ICN leave. All 25 acute trusts had access to an infection control doctor, but on-call cover in eight required this individual to be permanently available. All acute trusts had a hospital control of infection committee, but in only 10 did a senior member of management regularly attend. Twenty-four acute trusts had an outbreak control plan but only 13 had been updated as recommended. The NHS performance management structure needs to be utilised to ensure that these deficiencies are rectified. It would be wise to investigate implementation of national guidance in NHS trusts in other regions.

Enhanced surveillance of meningococcal disease in the West Midlands: 1996 to 1998.

Surveillance of meningococcal disease is vital if we are to respond to a changing burden of disease, but current sources of routine data suggest different trends. A scheme for enhanced surveillance of meningococcal disease began in the West Midlands in January 1996 using several data sources, including case reporting from consultants in communicable disease control, data from the PHLS Meningococcal Reference Unit, and monitoring of statutory notifications and laboratory reports. One thousand two hundred and twenty-eight cases of probable meningococcal infection were identified in three years (1996-1998), 594 of which were laboratory confirmed. Routine data for the same period yielded smaller totals--920 notifications and 412 laboratory reports--suggesting that these sources underestimate incidence by 25% to 30%. Diagnosis by polymerase chain reaction became increasingly important, and accounted for 38% of confirmed cases in 1998. A significant excess of male cases was observed (p < 0.01), most obvious in children under 5 years of age. There was no increase in N. meningitidis C2a strains, which had been identified as a threat nationally. A national system of enhanced surveillance has now been set up to inform programmes that aim to reduce the burden of meningococcal infection.

Immunization with Haemophilus influenzae (Hib) conjugate vaccine following discharge from hospital.

BACKGROUND: This study was undertaken to ascertain Haemophilus influenzae type b (Hib) conjugate vaccination status following discharge from hospital and to determine the time taken to vaccinate with Hib conjugate vaccine following hospital discharge of unvaccinated children. MATERIALS AND METHODS: Population-based cross-sectional survey involving children aged 3-59 months admitted to a hospital with laboratory confirmed invasive H. influenzae disease. RESULTS: Of 51 eligible children, 42 (82%) had not received Hib conjugate vaccine prior to admission. No children were immunized prior to discharge. Vaccination following discharge took an average of 110 days (range 3-441 days). More than one quarter (28%) remained unvaccinated following discharge. If these children had been immunized, immunization coverage among this group of children would have increased significantly from 73% to 98% (p = 0.0017). CONCLUSION: In the immediate post-Hib conjugate vaccine period, delayed immunization after discharge was identified. This reduces the individual and community benefits of immunization.

Influence of material deprivation on hospital admissions for gynaecologic infections.

This study was conducted to examine the relationship between age, material deprivation, and hospital admissions for selected gynaecologic infections in an English health region. Data from hospital episode statistics relating to hospital admissions for pelvic inflammatory disease (PID), infections of the uterus, and infections of the cervix, vagina, and vulva were obtained. Townsend deprivation scores (based on 1991 census data) were allocated by linking postcodes of cases to enumeration districts (EDs) and then assigning the EDs to appropriate quintiles of material deprivation. Both single variable and multivariable (Poisson regression) analyses were performed. For women with PID, the risk of hospitalisation increased with increasing deprivation (P<0.0001), and women in the most deprived quintile were at increased risk (relative risk [RR] 1.31; 95% confidence interval [95%CI] 1.24-1.39) for hospitalisation. Multivariable analysis identified an elevated risk of hospital admission in women aged 25-44 years for PID (RR 2.03; 95%CI 0.84-4.87) and infections of the cervix, vagina, and vulva (RR 1.47; 95%CI 1.16-1.87), and the incidence of both conditions increased significantly with age. In summary, the results obtained suggest that women from the most deprived areas are at greatest risk of hospitalisation for gynaecologic infections, particularly PID. Preventive measures together with earlier diagnostic, treatment, and referral procedures are required to reduce morbidity.

A national outbreak of multi-resistant Salmonella enterica serovar Typhimurium definitive phage type (DT) 104 associated with consumption of lettuce.

Between 1 August and 15 September 2000, 361 cases of Salmonella enterica serotype Typhimurium definitive phage type (DT) 104, resistant to ampicillin, chloramphenicol, streptomycin, sulphonamides, spectinomycin and tetracycline (R-type ACSSuSpT), were identified in England and Wales residents. Molecular typing of 258 isolates of S. Typhimurium DT104 R-type ACSSuSpT showed that, although isolates were indistinguishable by pulsed-field gel electrophoresis, 67% (174/258) were characterized by a particular plasmid profile. A statistically significant association between illness and consumption of lettuce away from home was demonstrated (OR = 7.28; 95% CI=2.25-23.57; P=0.0006) in an unmatched case-control study. Environmental investigations revealed that a number of food outlets implicated in the outbreak had common suppliers of salad vegetables. No implicated foods were available for microbiological testing. An environmental audit of three farms that might have supplied salad vegetables to the implicated outlets did not reveal any unsafe agricultural practices. The complexity of the food supply chain and the lack of identifying markers on salad stuffs made tracking salad vegetables back to their origin extremely difficult in most instances. This has implications for public health since food hazard warnings and product withdrawal are contingent on accurate identification of the suspect product.

A large outbreak of Q fever in the West Midlands: windborne spread into a metropolitan area?

The largest outbreak of the zoonotic disease Q fever recorded in the United Kingdom (UK) occurred in Birmingham in 1989. One hundred and forty-seven cases were identified, 125 of whom were males, and 130 of whom were between 16 and 64 years of age. Fewer cases of Asian ethnic origin were observed than expected (p < 0.01), and more smokers (p < 0.005). A case control study (26 cases and 52 matched controls) produced no evidence that direct contact with animals or animal products had caused the outbreak. The epidemic curve suggested a point source exposure in the week beginning 10 April. The home addresses of cases were clustered in a rectangle 11 miles (18.3 km) north/south by 4 miles (6.7 km) east/ west, and attack rates became lower towards the north. Directly south of this area were farms engaged in outdoor lambing and calving, a potent source of coxiella spores. A retrospective computerised analysis showed that the geographical distribution of cases was associated with a source in this area (p < 0.00001). On 11 April, unusual southerly gales of up to 78 mph (130 km/h) were recorded. The probable cause of the outbreak was windborne spread of coxiella spores from farmland to the conurbation.