Key Health Data for the West Midlands 2000

Chapter 4: Communicable Disease

Contacts

Preface

Contents

List of Tables
List of Figures

Abbreviations

Main Body

1: West Midlands Geography
2: Inequalities and Health
3: The Burden of Disease
4: Communicable Disease
5: Environment and Health
6: Progress on Targets set by "Our Healthier Nation"
7: Crime and Health
8: Drug Misuse

4.1 Introduction

Saving Lives: Our Healthier Nation, identifies tuberculosis (section 9.22), food poisoning (9.15-9.17), HIV (9.7), gonorrhoea (9.5) and Chlamydia (9.5-9.6) as threats to public health. In this section we present data on trends in these infections.

4.2 Tuberculosis

Tuberculosis (TB) is statutorily notifiable by the clinician treating the patient to the proper officer of the local authority in which the patient lives. In addition the Communicable Disease Surveillance Centre (CDSC), West Midlands, co-ordinates an enhanced surveillance system for tuberculosis which collects extra risk factor data. This system was introduced in 1999 with the help of the ‘Consultants for Communicable Disease Control’ (CsCDC’s) and Chest physicians.

Tuberculosis notification rates have fallen throughout this century, due to improving living conditions and improved treatment. However, since the 1960s this decline has slowed, coinciding with an increased number of cases in immigrants from higher prevalence countries. The number of notifications nationally actually rose from 1987 to 1992.

Figure 4.1 shows annual notification rates for tuberculosis for the West Midlands region from 1986 to 1999. Although the crude rate was higher in 1999 than the previous four years, it is still below the rates observed in 1989-94.

Nearly 60% of notified cases in the West Midlands region are in people of Indian subcontinent origin (Figure 4.2), a rate more than 25 times higher than that for the indigenous population. Although age-specific rates increase with age in all ethnic groups, numbers of cases are highest in young Asian adults (Figure 4.3). Enhanced surveillance will be particularly useful for monitoring the marked ethnic inequalities in this disease. District specific rates were presented in last year’s Key Health Data report (Chapter 10).

Figure 4.1: Rates of notified Tuberculosis cases in the West Midlands and England and Wales: 1986-1999

Figure 4.2: 1999 West Midlands TB cases - ethnic breakdown

Figure 4.3: West Midlands TB cases in 1999 by age group and sex

4.3 Food poisoning

Food poisoning (FP) is also statutorily notifiable, although, partly because of the vagueness of the case-definition, case-ascertainment is variable: notification rates by local authority are shown in Figure 4.4.

Trends in FP notifications show that the West Midlands followed the national trend of a marked increase from 1990-97, but the last two years show a slight decline (Figure 4.5).

Figure 4.6 shows trends in laboratory diagnoses of important gastrointestinal bacteria. Campylobacter remains the most commonly diagnosed gastrointestinalinfection, with reported rates doubling between 1991 and 1998. Some of this may be

due to improved ascertainment, but the epidemiology of this important organism remains poorly understood and consequently control measures are relatively undeveloped.

After the dramatic rise in salmonellosis in the 1980’s, predominantly caused by the poultry-associated S. enteritidis PT 4, Salmonella reports remained stable in the 1990’s before recording significant falls in the last two years. This decrease may be due to vaccination of poultry flocks.

Although Cryptosporidium has the potential to cause large outbreaks and E. coli O157 can cause serious illness, neither are major contributors to the overall rate of diagnosed infectious intestinal illness.

Figure 4.4: Food poisoning notifications by local authority 1999

Figure 4.5: Food poisoning in the West Midlands Region 1990-1999

Figure 4.6: Laboratory reports of selected gastrointestinal infections in the West Midlands Region 1990-1999

4.4 HIV

HIV infection is not notifiable, but the West Midlands has an enhanced surveillance scheme funded by the Public Health Levy. Incidence of newly diagnosed cases of HIV infection in the West Midlands remained fairly constant from 1990 to 1998 at about 100 cases per annum (Figure 4.7). An increased number of new infections were reported in 1999, although as this is not statistically significant the relevance of this is not yet clear.

Prevalence of HIV infection has increased substantially in the last three years: this is due to the increased effectiveness of antiretroviral therapy, which has led to a 40% decrease in AIDS diagnoses and a 60% decrease in deaths from HIV/AIDS (Figure 4.7). This is placing enormous strain on HIV treatment budgets.

Figure 4.8 shows an important change in the epidemiology of newly diagnosed infection in the region. Although the incidence of new cases thought to be acquired homosexually has remained stable (a disappointing outcome), cases acquired heterosexually have increased in recent years.

In 1999, for the first time, a similar number of heterosexually-acquired cases as homosexually-acquired were reported. The majority of heterosexually acquired cases have links with higher-prevalence countries, especially sub Saharan Africa.

Figure 4.7: Newly diagnosed HIV and AIDS and Deaths from AIDS, West Midlands, 1990-1999

Figure 4.8: Date of first positive test and probable route of transmission

4.5 Gonorrhoea and Chlamydia

Data on sexually transmitted infections (STI) other than HIV have only been available from the KC60 returns submitted from Genitourinary Medicine (GU) clinics. These data have important deficiencies such as lack of information on district of residence or ethnicity.

The regional HIV Surveillance Project is working with GU consultants to set up an active enhanced surveillance system for STIs, thus making it possible to monitor STI rates at subregional level for the first time.

Trends in KC60 data at regional level are shown in figures 4.9 (gonorrhoea) and 4.10 (Chlamydia).

Figure 4.9: Genital Chlamydia cases in the West Midlands Region 1995-1999

Figure 4.10: Gonorrhoea cases in the West Midlands Region 1995-1999

An academic unit for Communicable Disease Epidemiology and Control was established in 2000 as a joint venture between the PHLS Communicable Disease Surveillance Centre (CDSC West Midlands) and the University of Birmingham, funded by the Public Health Development Fund (PHDF). This Unit contributes to the West Midlands Public Health Observatory.

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