Communicable disease report. CDR review最新文献

In February 1996, sputum smear positive tuberculosis was diagnosed in an adolescent white girl born in the United Kingdom. The investigation was complex because the index case had attended two schools and had a large extended family. The extent of transmission was consistent with "adult" pulmonary disease; eight previously unvaccinated contacts showed evidence of infection: one had proven tuberculosis, four had pulmonary radiological changes and positive Heaf test results, and three had positive Heaf test results. Seven of the eight were family/ household contacts, the eighth was a school contact. Current guidelines for the management of tuberculosis in schools were followed in this investigation and it was concluded that they remain appropriate. The source of infection for the index case was not definitely established. It may have been an adult who presented with active tuberculosis in 1994. The index case had erythema nodosum with a normal chest radiograph in 1993.

The re-emergence worldwide of tuberculosis as a major threat to public health and continuing and changing challenges in the control of tuberculosis in England and Wales provide the basis for the designation, by the PHLS, of tuberculosis as a priority area. In addition to the mycobacteriology reference services provided by the PHLS in England and Wales (summarised in an accompanying article) the PHLS contributes to the control of tuberculosis through its surveillance and other epidemiological work. This article summarises the range of this work, emphasising the collaborative nature of the effort required for surveillance, prevention, and control of tuberculosis.

Tuberculosis (TB) is the most important cause of infectious disease in the world, with eight million new cases and three million deaths each year. The increasing incidence of TB in the developed and the developing world, increasing drug resistance, and the occurrence of nosocomial outbreaks of drug sensitive as well as drug resistant TB has led the PHLS to establish TB as a priority area. This article reviews the enhanced reference services for mycobacteriology provided by the PHLS in England and Wales. These include microscopy and culture on solid and liquid media, rapid culture systems, identification of mycobacteria using macroscopic, microscopic, growth, and biochemical characteristics, and molecular DNA analysis. The Mycobacterium Reference Unit (MRU) provides rapid molecular DNA amplification techniques to identify Mycobacterium tuberculosis in specimens. All four PHLS Regional Centres test isolates for drug susceptibility. This work is quality controlled by MRU, which is one of the World Health Organisation's reference centres for global surveillance on drug resistance in tuberculosis. National data on drug resistance are collated through 'Mycobnet', a surveillance scheme run through the collaboration of PHLS and other UK reference centres and the PHLS Communicable Disease Surveillance Centre.

A wedding reception at a North Yorkshire hotel was followed by an explosive outbreak of gastroenteritis. The attack rate among the 111 guests was 50% and vomiting was a predominant feature. The results of laboratory and epidemiological investigations were consistent with a common source outbreak of small round structured virus (SRSV) infection genotype II. The source of the outbreak was traced to a kitchen assistant who suddenly became ill on the eve of the reception and vomited into a sink used for preparing vegetables. The sink was cleaned with a chlorine based disinfectant and used the next morning to prepare a potato salad, subsequently identified as the vehicle of infection in a cohort study of guests (odds ratio 3.21; CI 1.78-5.78, p = 0.0001). No other food was associated with illness. The outbreak provides further supporting evidence of the importance of vomiting in the transmission of SRSV infection, highlights the virulence of this group of viruses, and indicates their relative resistance to environmental disinfection and decontamination. It also highlights the need for the adequate training of catering staff and the implementation and enforcement of food hygiene regulations.

Accurate estimates of expected survival times and survival rates of AIDS patients are important both for estimating the prognosis of individuals and for monitoring the progress of the HIV/AIDS epidemic as new treatments are introduced. They are also needed for projecting future numbers of AIDS cases. Data on reported AIDS cases held at the PHLS AIDS Centre at the Communicable Disease Surveillance Centre and the Scottish Centre for Infection and Environmental Health confirmed the time, age, and reporting delay effects identified in earlier analyses of the United Kingdom AIDS database. The duration of survival after AIDS is diagnosed has improved since the epidemic began--median survival was 10.6 months in cases diagnosed before 1987 and has been at least 18.4 months in cases diagnosed each year since then. People who are diagnosed younger live longer--median survival fell from 21.6 months at age 15 to 29 to 12.6 months at age 45 or over. Delay in reporting AIDS cases adversely affects survival estimates for cases reported in recent years. Survival was longer in cases reported over a year after diagnosis of AIDS--23.7 months compared with 16.9 months in those reported less than a year after diagnosis. The experience of the hospital, measured by its cumulative AIDS caseload, was an important factor in the survival of men who have sex with men presenting with Kaposi's sarcoma alone or 'other' diagnoses--survival was shorter for cases reported from smaller centres. Men who have sex with men with Pneumocystis carinii pneumonia alone or other opportunistic infections alone who were known to be HIV positive before being diagnosed with AIDS had a shorter survival after being diagnosed than those who were unaware of their HIV infection. This supports the hypothesis that treatment for HIV infection and prophylaxis may extend the period before AIDS develops but reduce the period between developing AIDS and dying.

Gastroenteritis is a major cause of illness in young children worldwide. The magnitude of this problem is underestimated, as many cases may not present for medical treatment and many that do present are not asked to provide a faecal specimen. In this study, laboratory reports of pathogens responsible for gastroenteritis in children under 5 years in England and Wales reported to the PHLS Communicable Disease Surveillance Centre from January 1990 to December 1994 were analysed. These reports were compared with food poisoning notifications and mortality attributable to gastroenteritis collated by the Office of Population Censuses and Surveys in the same age group over the same period. Thirty-nine per cent of the 167630 laboratory faecal identifications were of rotavirus. Reports were commonest in children under 1 year of age during the winter months. Salmonellas and campylobacters were isolated from 16% and 15% of the specimens reported respectively. During the study period salmonella reporting rates rose by 48% in this age group. Improving the microbiological quality of food and raising standards of food hygiene, together with increasing parental awareness of the possibility of food poisoning in young children, will help to reduce morbidity in this age group. The majority of childhood deaths attributable to gastroenteritis were associated with rotavirus infection. The introduction of recently developed vaccines against rotavirus could substantially reduce the level of morbidity in this age group.

Preliminary enquiries following prompt notification of three cases of suspected food poisoning revealed that they had all attended the same three functions during the preceding weekend. Subsequent investigation identified 49 people with gastrointestinal symptoms, 13 of whom were infected with Salmonella enteritidis phage type 6. Forty-five of those with symptoms, including 11 with confirmed infection, had eaten a buffet meal at a public house. Eating egg sandwiches was strongly associated with infection. Defects in the kitchen structure and the storage and handling of the implicated food items provided the potential for cross contamination. Salmonella was isolated from several environmental sites, including a general purpose cleaning cloth. Two different quiches and pork pies, which were possible vehicles of infection were thought to have been contaminated after being brought into the kitchen. The investigation did not reveal whether or not shell eggs used in the sandwiches were the original source or whether they too had been contaminated during their preparation.