Birth outcomes following treatment for precancerous changes to the cervix: a population-based record linkage study.

OBJECTIVE: To examine whether treatments for precancerous changes to the cervix are associated with adverse birth outcomes in subsequent pregnancies. DESIGN: Population-based retrospective cohort study using electronic linkage of data from the Welsh cervical screening programme and a national routine child health database. SETTING: Wales. POPULATION: A total of 174,325 women aged 20-39 years who received cervical screening between April 2001 and March 2004. METHODS: Logistic regression was used to compare the odds of each birth outcome between women who had negative cervical smears and women who received either colposcopy ± punch biopsy only or colposcopy and excisional or ablative treatments, adjusted for confounding factors (e.g. age, social deprivation and smoking). MAIN OUTCOME MEASURES: Preterm birth (before 37, 32 and 28 weeks of gestation), and low birthweight (<2500 g). RESULTS: Compared with women who had negative cervical smears, the odds ratio for preterm birth (<37 weeks) was significantly increased in women who had colposcopy only (adjusted odds ratio 1.54, 95% CI 1.32-1.80) and single excisional treatment (adjusted odds ratio 1.77, 95% CI 1.47-2.13). Similar results were observed for preterm birth at <32 weeks of gestation. There was no increased risk of preterm birth or low birthweight for women who had treatment compared with women who had colposcopy only. CONCLUSION: Women who were referred for colposcopy had an increased risk of preterm births regardless of whether or not they received treatment to the cervix. This increased risk could be the result of common risk factors for abnormal smears and preterm birth.

A case-control study to estimate the impact on breast cancer death of the breast screening programme in Wales.

OBJECTIVES: The aim of this study was to estimate the effect of service screening, as provided by the NHS breast screening programme, on breast cancer mortality in Wales. Furthermore, we wished to ascertain whether a reduction in breast cancer mortality consistent with that observed in the randomised screening trials was being achieved. SETTING: The NHS Breast Screening Programme in Wales, managed by Breast Test Wales, with headquarters in Cardiff. METHODS: A case-control study design with 1:2 matching. The cases were deaths from breast cancer in women aged 50-75 years at diagnosis who were diagnosed after the instigation of screening in 1991 and who died after 1998. The controls were women who had not died of breast cancer or any other condition during the study period. One was from the same GP practice and the other from a different GP practice within the same district, matched by year of birth. RESULTS: Based on 419 cases, the odds ratio for risk of death from breast cancer for women who have attended at least one routine screen compared to those never screened was 0.62 (95% confidence interval [CI] 0.47-0.82, p=0.001). After excluding cases diagnosed prior to 1995 and adjusting for self-selection bias, the estimated mortality reduction was 25% (odds ratio=0.75, 95% CI 0.49-1.14, p=0.09). CONCLUSION: The Breast Test Wales screening programme is achieving a reduction in breast cancer mortality of 25% in women attending for screening, which is consistent with the results of the randomized controlled trials of mammographic screening.

Addressing environmental health concerns near Trecatti landfill site, United Kingdom.

Residents near the Trecatti landfill site located in South Wales, United Kingdom, expressed concern about odors and health effects they attributed to site emissions. The authors compared routinely collected, population-based, health data from potentially exposed electoral wards (i.e., United Kingdom electoral tracts) with data from both wards nearby, matched for socioeconomic deprivation scores, and with wards where residents were likely to attend the same hospital. Mortality rates were higher for all causes and neoplastic diseases (but not respiratory disease) in the exposed wards, but there was no change in rates after the site opened. Hospital data revealed a transient increase in admissions for asthma during the 3 yr that preceded the peak in odor complaints. The birth prevalence of congenital malformations was raised in the exposed wards, but the authors could not exclude a possible artifact resulting from differences in reporting practices between hospitals. The absence of environmental monitoring in the community during the period of public concern was a significant weakness of this study.

Community exposures to chemical incidents: development and evaluation of the first environmental public health surveillance system in europe.

OBJECTIVE: To describe the frequency, nature and location of acute chemical incidents in Wales, and the morbidity in employees, emergency responders and the general public who were exposed. DESIGN: Active multi-agency community-based surveillance system. SETTING: Wales, 1993-5. MAIN OUTCOME MEASURES: Frequency, nature and location of incidents, populations potentially exposed and with symptoms. RESULTS: Most of the 402 incidents identified were not associated with sites governed by the Control of Industrial Major Accident Hazard Regulations but with smaller industrial sites and commercial premises. About two in every thousand of the estimated 236 000 members of the public considered to be at risk from exposure reported symptoms, which were mainly nausea, headaches, and irritation of the eye, skin and respiratory tract. The most commonly reported chemicals that members of the public were exposed to were smoke toxins, miscellaneous organics, toxic gases and flammable gases. A health authority was reported to be involved in only 34 (8%) of the incidents and in only 3 of the 29 incidents where more than 100 members of the public were exposed. CONCLUSION: A geographically defined, multi-agency surveillance system can identify high risk locations and types of incidents, together with the chemicals most likely to be involved. Such ongoing surveillance information is essential for appropriate policy making, emergency planning, operational management and training.

Investigation of an acute chemical incident: exposure to fluorinated hydrocarbons.

OBJECTIVES: To assess whether attendance at the site after an incident in a sewer was associated with symptoms in emergency personnel and whether the prevalence of symptoms was associated with estimated levels of exposure to any chemical hazard. METHODS: Symptoms experienced by people attending an incident involving two dead sewer workers suggested the presence of a chemical hazard, before environmental sampling confirmed any toxic agent. Self reported symptoms, estimated exposures, and biomarkers of exposure for likely agents from all 254 people who attended the incident and a referent occupational group matching the 83 emergency personnel who went to the Accident and Emergency department (A and E) in the first 48 hours were recorded. The prevalence of symptoms and concentrations of creatine phosphokinase in serum of the 83 early patients at A and E were compared with their referent occupational group. In all workers who attended the incident, the trends in symptom prevalences and concentrations of creatine phosphokinase in serum were examined by distance from the site and predefined exposure category. RESULTS: Among all workers who attended the incident, symptoms of shortness of breath and sore throat were significantly associated with indirect estimates of exposure but not associated with concentrations of creatine phosphokinase. Freon was detected in two blood samples. The early patients at A and E reported more symptoms than their matched reference group and their median concentrations of creatine phosphokinase were higher. CONCLUSIONS: The association between symptoms and concentrations of creatine phosphokinase with attendance at the site indicated the presence of a continuing hazard at the site and led to extra precautions being taken. Comparison values from the referent occupational group prevented unnecessary medical follow up.

Assessment of impact on health of residents living near the Nant-y-Gwyddon landfill site: retrospective analysis.

OBJECTIVES: To compare indices of health in a population living near a landfill site with a population matched for socioeconomic status and to review environmental monitoring data. DESIGN: Ecological study with small area statistics and environmental reports. SETTING: Electoral wards in valleys of South Wales. SUBJECTS: Populations in the five wards near the landfill site who had formally complained of odours (exposed population), and comparison populations in 22 wards in the same unitary authority within the same fifth of Townsend score. OUTCOME MEASURES: Mortality, rates of hospital admission, measures of reproductive health (proportion of all births and stillbirths of infants weighing <2500 g; rates of admissions for spontaneous abortion; rates of all reported congenital malformations). Environmental data on site emissions. RESULTS: There were no consistent differences in mortality, rates of hospital admissions, or proportion of low birthweight infants between the two populations. There was an increased maternal risk of having a baby with a congenital abnormality in residents near the site, both before its opening (relative risk 1.9; 95% confidence interval 1.3 to 2.85; P<0.001) and after (1.9; 1.23 to 2.95; P=0.003). Environmental monitoring showed that hydrogen sulphide from the site was probably responsible for odours. CONCLUSIONS: The area surrounding the landfill site has an increased rate of reported congenital malformations, which predated the opening of the landfill, although the cluster of cases of gastroschisis post-dated its opening. Several chemicals emitted from the site, including hydrogen sulphide and benzene, were found in air samples in the nearby community. Further studies of the reproductive risk in such communities are needed to examine the safety of waste disposal sites.

An international outbreak of Salmonella enteritidis associated with lasagne; lessons on the need for cross-national co-operation in investigating food-borne outbreaks.

We investigated an outbreak of Salmonella enteritidis involving at least 19 British tourists returning from one hotel in another European country. A retrospective cohort study of 47 hotel guests identified lasagne as the most likely vehicle of transmission (RR 11.5; 95% CI 3.0-44.1; P < 0.0001). However, difficulties in information exchange and lack of formal mechanisms to agree on the aims of the cross-national investigation hampered efficient management of the outbreak. The factors leading to contamination of the food vehicle were not identified and therefore specific action to prevent reoccurrence could not be taken. There is need to develop protocols for cross-national investigations of outbreaks in Europe which should include specifying objectives, roles and responsibilities of investigators and control agencies, with formal reporting of the outcome of the investigation.

A study of postoperative fever following paediatric tonsillectomy.

The aetiology of post-tonsillectomy fever is obscure. Bacteraemia during surgery, anaesthetic agents and the inflammatory response of tissue to injury have been implicated. A prospective study was undertaken in 100 consecutive children to evaluate the occurrence and severity of fever in the 24 h after tonsillectomy and its relationship to bacteraemia during surgery and qualitative and quantitative cultures (colony counts) of organisms in tonsil core tissue. Fifty-four patients had a fever (> 37.5 degrees C) postoperatively, of whom, 30 had a fever greater than 38 degrees C. Blood cultures during tonsillectomy were positive in 22 patients. There was no statistically significant difference between the occurrence of fever and the techniques of tonsillectomy and haemostasis. There was also no association between positive blood, core or surface cultures and the incidence or severity of fever nor any association between colony count in core cultures and fever. Our results suggest that postoperative fever in the 24 h following tonsillectomy is not caused by infection.

Effect of environmental tobacco smoke on peak flow variability.

This study was undertaken to determine whether exposure to various indoor pollutants is associated with a higher prevalence of respiratory symptoms, a diagnosis of asthma, or more variable peak flow rates. Four hundred and twenty-six children aged 8-11 years in four junior schools at three locations recorded respiratory symptoms and diagnosis of asthma using the ISAAC questionnaire. Daily peak flow measurements were taken during two six-week periods (winter and summer). Symptoms in children with and without asthma were not related to gas fires, cookers, smokers, or pets in the home. However, the variability of lung function, expressed as the coefficient of variation, in all children was increased with a household smoker. Environmental tobacco smoke increases airways variability in children with and without asthma. Its effects were not apparent from a questionnaire completed by parents, and the coefficient of variation of serially measured peak flows was a more sensitive indicator of lung function.