10.1 Introduction

The Health Protection Agency (HPA) is responsible for collating Notifications of Infectious Diseases (NOIDs).  The HPA West Midlands Regional Epidemiology Unit (REU) uses NOIDS data on measles and mumps along with other surveillance data to monitor disease trends, vaccination coverage levels and also identify outbreaks and clusters.  These NOIDS based surveillance information on measles and mumps are currently disseminated on a quarterly basis via a report that is circulated to all Primary Care Trust (PCT) leads and Health Protection Units in the region. 

10.2 Notification of Infectious Diseases (NOIDs)

There has been a statutory requirement to notify certain infectious diseases since the end of the 19th century. Diseases such as cholera, diphtheria, smallpox and typhoid had to be reported in London from 1891 and the rest of England and Wales from 1899. In 2010 the Health protection legislation in England was updated and the revised measures are contained within the amended Public Health (Control of Disease) Act 1984 and its accompanying Regulations1, 2. These new Regulations for clinical notifications came into force on 6th April 2010 and in addition to a specified list of infectious diseases which now includes 30 diseases, there is also a requirement for Registered Medical Practitioners (RMPs) to notify cases of other infections or contamination which could present a significant risk to human and public health¹.

The prime purpose of the notification system is to provide a timely system for detecting possible outbreaks and epidemics. The accuracy of the diagnosis is secondary and need only be based on clinical suspicion. As notifications are based on clinical suspicion there are limitations to the data which should be considered when interpreting the data. Nevertheless, NOIDs data are very important for showing trends over time.

10.3 Immunisation data

The Measles, Mumps and Rubella vaccine (MMR) was introduced in Britain in 1988.  This is one of the vaccine programmes monitored  by the HPA Centre for Infections (CfI) which collates UK immunisation coverage statistics from child health information systems for children who have reached their first, second or fifth birthday during each reporting quarter.  Data are produced every quarter by the HPA3 and annual national data are available back to 1997.  Data included in this chapter are for Quarter 3 2006 (October – December) to Quarter 3 2009 (October to December). 

10.4 Results

NOIDs

10.4.1 Measles in the West Midlands, 1989 – 2009

Notifications of measles in the West Midlands have steadily decreased in the last 20 years with a small increase seen in the last two years (Figure 10.1).  This small increase may be a residual effect partly attributable to the decrease in MMR vaccine uptake in the target age group that arose following negative publicity about the vaccine.

Notifications have decreased from over 3,000 (59.2 per 100,000) in 1989 to just under 500 (8.8 per 100,000) in 2009.  At the beginning of this time period, rates observed in the West Midlands were above those in England and Wales.  However in the last few years measles notifications in the West Midlands have been lower than in England and Wales.

Figure 10.1: Number and rate of measles notifications in the West Midlands and England & Wales, 1989 – 2009

Number and rate of measles notifications in the West Midlands and England & Wales, 1989 – 2009

In 2009 in the West Midlands, notifications varied from 15.1 per 100,000 in Birmingham and Herefordshire to 2.0 per 100,000 in Worcestershire and South Staffordshire (Figure 10.2).  Overall rates in the West Midlands were lower than in England and Wales (8.8 per 100,000 compared to 9.6 per 100,000).

Figure 10.2: Number and rate of measles notifications in the West Midlands, 2009

Number and rate of measles notifications in the West Midlands, 2009

10.4.2 Mumps in the West Midlands 1989 – 2009

Clinical notifications of mumps in the West Midlands decreased from 1,546 notifications (30.0 per 100,000) in 1989 to 151 notifications (2.9 per 100,000) in 1998 (Figure 10.3).  In recent years, notifications have increased again peaking to 5,640 (105.4 per 100,000) in 2005.  Throughout most of this time period, rates in the West Midlands have been similar to those in England and Wales, however in 2009 rates were 22.0 per 100,000 in the West Midlands compared to 34.1 per 100,000 in England and Wales.  Nationally, an increase was observed in 2003 which continued in 2004 and 2005.  In the West Midlands this increase started towards the end of 2004 and peaked in 2005 before decreasing to 2004 levels the following year. 

During this time of increased incidence the majority of reported cases were in older teenagers and younger adults particularly those in the 15-24 age group with many of these cases associated with outbreaks in universities and colleges across England and Wales4.  This observed increase in susceptibility in the 15-24 age group may be attributed to low levels of natural immunity (as very few persons in this age group had been previously infected) and also low levels of acquired immunity because they either never received the MMR vaccine as they were too old when it was introduced in 1988 or may have received only one dose⁵.

Figure 10.3: Number and rate of mumps notifications in the West Midlands and England & Wales, 1989 – 2009

Number and rate of mumps notifications in the West Midlands and England & Wales, 1989 – 2009

In 2009 mumps rates were highest in Solihull, Coventry and Herefordshire (32.0, 32.3 and 33.4 per 100,000 respectively) (Figure 10.4).  Overall the West Midlands rate was lower than the England and Wales rate (22.0 per 100,000 compared to 34.1 per 100,000). 

Figure 10.4: Number and rate of mumps notifications in the West Midlands, 2009

Number and rate of mumps notifications in the West Midlands, 2009

10.4.3 MMR coverage data

In recent years (2006-2009), MMR coverage has increased in the West Midlands both at 24 months and five years of age (Figures 10.5, 10.6 and10.7).  This improvement may be linked to the introduction of immunisation performance indicators within the Vital Signs programme as part of the NHS Operating Framework6.  Throughout this time period, coverage in the West Midlands has been above coverage in England both at 24 months and 5 years. 

During this time period, the overall uptake of the first dose of the MMR vaccine (MMR1) by 24 months of age was highest in Heart of Birmingham tPCT and North Staffordshire PCT.  The lowest coverage was observed in Herefordshire PCT and Coventry tPCT.  All PCTs in Shropshire and Staffordshire had higher coverage than the England average during this time. 

In the most recent quarter (2009 Q3), West Midlands coverage was at 90.7% with Warwickshire PCT having the highest coverage (95.2%) increasing from 87.9% in 2008 Q4.  Coventry tPCT also saw a large increase from 79.4% in 2008 Q4 to 92.4% in the most recent quarter.

Figure 10.5: Uptake of MMR1 at 24 months in the West Midlands and England, 2006 – 2009

Uptake of MMR1 at 24 months in the West Midlands and England, 2006 – 2009

The highest coverage for the MMR1 at five years of age (Figure 10.6) was in Heart of Birmingham tPCT and Stoke on Trent PCT.  Lowest coverage was in Herefordshire and Solihull PCTs.  Again all PCTs in Shropshire and Staffordshire had higher coverage than the England average during this time.  In the most recent quarter, the regional coverage was 93.5% with Coventry tPCT having the highest coverage (96.9%) increasing from 89.5% in 2009 Q2. 

Figure 10.6: MMR1 5 years in the West Midlands and England, 2006 – 2009

MMR1 5 years in the West Midlands and England, 2006 – 2009

The highest coverage for the booster dose at 5 years (Figure 10.7) was in North Staffordshire and Stoke on Trent PCTs.  The lowest uptake was in Birmingham East and North and South Birmingham PCTs.  Again the largest increase in the recent quarter was seen in Coventry tPCT which increased from 76.6% in 2009 Q2 to 90.6% in Q3.  In the most recent quarter the West Midland’s coverage was 86.3%.

Figure 10.7: Uptake of pre-school booster (MMR2) at 5 years in the West Midlands and England, 2006 – 2009

Uptake of pre-school booster (MMR2) at 5 years in the West Midlands and England, 2006 – 2009

10.5 Discussion

In recent years, MMR coverage in the West Midlands has continued to increase but most PCTs do not yet meet the World Health Organisation (WHO) recommended target of ≥95%7.  Achieving this vaccination threshold is needed to interrupt and reduce transmission in the community and ensure adequate herd immunity. 

Notifications of measles and mumps have increased in the most recent years with most of the observed increases in 2008 and 2009 linked to clusters and outbreaks in the region.  Following a measles outbreak that started in autumn 2008, the HPA West Midlands commenced enhanced surveillance of all cases reported to inform the outbreak management. The findings showed that between 1st November 2008 to the 31st March 2009 the majority of reported cases occurred in Warwickshire PCT (22%) and the majority of laboratory confirmed cases were in children aged less than 5 years (52%) and between 5 and 14 years (33%).  Where known, 64% of cases had not had their MMR vaccine, 27% had received at least 1 dose and 9% had received 2 doses. 

The HPA and NHS continue to promote MMR vaccination and regularly remind parents of the importance of children receiving two doses before they start school. 

References

1. HPA/NOIDs:  http://www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/NotificationsOfInfectiousDiseases/  Last accessed 16^th April 2010. 


2. OPSI: http://www.opsi.gov.uk/si/si2010/uksi_20100659_en_1.  Last accessed 16^th April 2010. 


3. HPA/COVER data:  http://www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/VaccineCoverageAndCOVER/.  Last accessed 24^th June 2010.


4. Savage E, Ramsey M, White J, et al.  Mumps outbreaks across England and Wales in 2004: observational study. BMJ 2005; 330:1119. 


5. Olowokure B, Clark L, Elliot AJ, et al.  Mumps and the media: changes in the reporting of mumps in response to newspaper coverage.  J Epidemiol Community Health 2007;61:385. HPA/immunisation data:  http://www.hpa.org.uk/hpr/infections/immunisation.htm#cover.  Last accessed 6^th July 2010.


6. WHO:  http://www.euro.who.int/__data/assets/pdf_file/0008/79028/E87772.pdf.  Last accessed 6^th July 2010.