Monitoring the emergence of community transmission of influenza A/H1N1 2009 in England: a cross sectional opportunistic survey of self sampled telephone callers to NHS Direct.

OBJECTIVE: To evaluate ascertainment of the onset of community transmission of influenza A/H1N1 2009 (swine flu) in England during the earliest phase of the epidemic through comparing data from two surveillance systems. DESIGN: Cross sectional opportunistic survey. STUDY SAMPLES: Results from self samples by consenting patients who had called the NHS Direct telephone health line with cold or flu symptoms, or both, and results from Health Protection Agency (HPA) regional microbiology laboratories on patients tested according to the clinical algorithm for the management of suspected cases of swine flu. SETTING: Six regions of England between 24 May and 30 June 2009. MAIN OUTCOME MEASURE: Proportion of specimens with laboratory evidence of influenza A/H1N1 2009. RESULTS: Influenza A/H1N1 2009 infections were detected in 91 (7%) of the 1385 self sampled specimens tested. In addition, eight instances of influenza A/H3 infection and two cases of influenza B infection were detected. The weekly rate of change in the proportions of infected individuals according to self obtained samples closely matched the rate of increase in the proportions of infected people reported by HPA regional laboratories. Comparing the data from both systems showed that local community transmission was occurring in London and the West Midlands once HPA regional laboratories began detecting 100 or more influenza A/H1N1 2009 infections, or a proportion positive of over 20% of those tested, each week. CONCLUSIONS: Trends in the proportion of patients with influenza A/H1N1 2009 across regions detected through clinical management were mirrored by the proportion of NHS Direct callers with laboratory confirmed infection. The initial concern that information from HPA regional laboratory reports would be too limited because it was based on testing patients with either travel associated risk or who were contacts of other influenza cases was unfounded. Reports from HPA regional laboratories could be used to recognise the extent to which local community transmission was occurring.

Influenza vaccine uptake and distribution in England and Wales using data from the General Practice Research Database, 1989/90-2003/04.

BACKGROUND: Routinely collected data from patients registered with general practices participating in the General Practice Research Database (GPRD) were used to analyse influenza vaccine uptake and distribution in England and Wales between 1989/90 and 1996/97. Major changes to influenza immunization policy were introduced in 1998 and 2000 when immunization of the elderly became age related rather than risk related. This new study examines trends in vaccine uptake for high- and low-risk patients and the impact of the policy changes on uptake in the elderly. METHODS: Between 0.5 and 2.7 million patients registered with practices participating in the GPRD from 1989 to 2004 were included. Data were examined by age group, medical risk group and evidence of vaccination per study year. RESULTS: Vaccine uptake among high-risk persons aged 65 or more increased from 36.7 per cent in 1989/90 to 72.1 per cent in 2003/04. For the same period, uptake rates for high-risk persons under 65 years increased from 10.8 to 24.3 per cent. For those at high risk, uptake by females was higher in all age groups up to 65 years. Of those that were vaccinated, a higher proportion of the 65 and over were vaccinated in October each year compared with the high risk under 65 (p < 0.001). CONCLUSIONS: Coverage among high-risk patients in younger age groups continues to fall well below satisfactory levels, especially among the youngest groups. Government policy should now focus on ways to improve uptake in these patients.

Influenza vaccine uptake in the elderly: results from a rapid assessment of the effectiveness of new government policy in England for the winters 2000/2001 and 2001/2002.

Immunisation against influenza is an important means of reducing morbidity and mortality amongst high-risk groups, and especially the elderly. Although immunisation has been recommended for these groups for many years, no timely or comprehensive monitoring at the national level was carried out in England before the beginning of this century. Annual numbers of doses administered were available, but not to whom they were given. This paper describes the results of a national rapid reporting scheme for England that was introduced by the Department of Health (DH) and PHLS Communicable Disease Surveillance Centre (CDSC). The scheme collected monthly data on influenza immunisation uptake among people aged 65 or more during the winters of 2000/2001 and 2001/2002. Results showed that DH annual targets of 60 and 65%, respectively were both met, although considerable variation occurred at the local levels. The feasibility of this method of monitoring immunisation uptake in the elderly is discussed.