This section deals with some key communicable diseases in the district: food poisoning, menigitis and cryptosporidium. It also addresses the rise in antibiotic resistance and declining immunisation uptake rates.

The legal basis for the control of communicable disease in England and Wales is laid down in the Public Health (Control of Disease) Act 1984, and the Public Health (Infectious Diseases) Regulations 1988. Table 3.1 lists the 32 currently 'notifiable' diseases.

Doctors caring for patients suspected or known to be suffering from a notifiable disease have a statutory duty to notify the proper officer of the district council where that patient lives. Notification should be done as quickly as possible by completing the correct written form. Neither a telephone call nor the sending of a laboratory result constitutes a formal notification. However, an initial telephone call to the public health department in cases of suspected meningitis or suspected outbreaks of food poisoning allows a prompt response and implementation of control measures.

Table 3.2 shows the trends in notifiable diseases reported in Portsmouth and South East Hampshire over the past eight years. The number of reported cases of food poisoning continues to rise. It has long been recognised nationally that there is substantial under reporting of some notifiable diseases. This is highlighted by the data on food poisoning and meningitis presented in this report. The number of cases formally notified by doctors is smaller than the numbers identified from laboratory sources and a recent study estimates that infectious intestinal disease occurs in one in five people each year, of whom only one in six attend their general practitioner. (1)

Table 3.3 shows the number of episodes of notifiable diseases that required hospital admission over the past three years. The main illnesses leading to admission were food poisoning, suspected meningitis and hepatitis B and C. There was a rise in admissions for 'suspected’ meningitis and acute hepatitis B and C, but a fall in admissions for food poisoning.

Food poisoning

Table 3.4 shows the overall number of notified cases of food poisoning by Local Authority since 1991. All areas have shown substantial increases between 1995 and 1998. It is not possible to tell whether this represents an increase in occurrence of food poisoning or an increased proportion of cases notified by GPs. Substantial under reporting of suspected and confirmed cases of food poisoning is known to occur and the notified cases only represent the 'tip of the iceberg’.

Table 3.5 shows that the overall number of laboratory confirmed cases of food poisoning has not changed over the past year. However, the number of cases caused by campylobacter has continued to rise but has been offset by a fall in the number of cases of salmonella. Campylobacter is almost always spread by eating inadequately cooked contaminated food. There has also been a fall in the number of cases of giardia and cryptosporidia since the peak in 1995 but the changes during the last year have not been notable.

Food poisoning can be due to contamination that occurs during food manufacturing, retailing or during the preparation, storage or cooking of foods. These issues are addressed both in businesses and with individual members of the public by the work of environmental health officers. In 1998 a Community Based Communicable Disease Strategy Group was established. Members include the Health Authority, local authority environmental health and education departments, and others. The aim of the group is to improve the health of the population through the prevention and control of communicable diseases by raising the knowledge and awareness of the population.

One area that the group will focus on is the prevention of food poisoning. Throughout the year it will raise public awareness about food hygiene, handling and storage and provide additional information before the start of the barbecue and picnic season.

Meningitis

Meningitis is a term that describes an inflammation of the lining of the brain. It may be caused by many different viral and bacterial organisms; this report concentrates on bacterial meningitis. Meningococcal meningitis is the commonest type of bacterial meningitis and the type that causes most public concern. The meningococcus bacteria also cause meningococcal septicaemia (blood poisoning) - an equally serious infection and they represent a spectrum of meningococcal disease.

Fig 3.1 shows the geographical distribution of cases of meningococcal meningitis and septicaemia in Portsmouth and South East Hampshire in the years 1997 and 1998. Table 3.6 shows the number of laboratory confirmed cases of meningitis since 1991. The number of cases varies in different parts of the Health Authority and change over time. All cases were investigated and the contacts identified. No links were identified between any of the cases.

Portsmouth and S E Hampshire Residents

¹ Meningococcal disease includes meningococcal meningitis and septicaemia. ² Both cases were adults

Over the last four years the number of confirmed cases of meningococcal meningitis and septicaemia has risen. This reflects the rise in number of cases seen nationally and may also reflect new and improved diagnostic techniques. No new cases of Haemophilus meningitis in children occurred after the introduction of childhood Hib vaccination in 1992. Streptococcal meningitis is a rare cause of meningitis affecting very small babies or the elderly.

Table 3.7 shows the cases of meningococcal meningitis and septicaemia by group. The two most common types of meningococcal disease in Portsmouth and South East Hampshire (as in England and Wales) are B and C. The percentage of cases caused by type C have increased both locally and nationally in the last two years. It is important to know the group of the organism because a vaccine is available that offers protection against meningococcal illness resulting from group A and C. This information enables Public Health staff to organise vaccination of the patient's close contacts.

* Other indicates meningococcus of other groups

** Clinical cases are those where tests did not confirm the presence of meningoccus bacteria

Meningococcal disease affects certain age groups in the population, with children being most at risk. Group B occurs more often in very young children whilst group C affects young adults to a greater extent. However, even in the 0 to 4 year age group meningococcal illness is rare. There were 12 cases in the 33,000 children in this age group in 1998 giving an incidence rate of 3.6 cases per 10,000 children per year.

Prevention of Meningitis and its Complications. Early diagnosis and treatment of meningitis or septicaemia can prevent death or the disability that may sometimes result. Awareness of the symptoms of meningitis is the most important factor that can lead people to seek medical attention. However, it can be difficult to identify someone in the early stages of meningitis, as the symptoms can be similar to common illnesses such as ?flu’. An injection of penicillin by a GP as soon as they suspect a patient may have meningitis or septicaemia is vitally important and can save lives. The Community Based Communicable Disease Strategy Group will continue to disseminate information to help with early recognition of the symptoms of meningitis, particularly in the autumn before the expected winter increase in meningitis occurs.

The opportunity to prevent most forms of meningitis is limited. Prophylactic antibiotics are recommended for close household contacts of cases of meningococcal meningitis and these individuals are identified by public health staff once they are informed about a suspected case. The purpose of giving prophylactic antibiotics is to reduce the spread of the organism amongst close family or household contacts. They do not prevent the development of meningitis in susceptible individuals who may already be carrying the meningococcus bacteria.

Vaccination against Haemophilus influenzae (Hib) has been very successful with no new cases in children since the immunisation programme started in 1992. At present there is no effective vaccine against the most common group B strains of meningococcal meningitis. Vaccines are available against groups A and C but they do not provide adequate protection in children aged under 2, and the immunity they give is not long lasting. For these reasons routine immunisation with this vaccine is not recommended. New more effective vaccines are expected soon against the A and C groups and a vaccine against the B group is being tested. Once more effective vaccines become available the limited use of vaccination against meningococcal meningitis is likely to change.

Cryptosporidium

Cryptosporidium is an organism that causes diarrhoea illness in humans. It is a common organism in domestic and farm animals. It is spread from hand to mouth (the faeco oral route) and so can be spread from person to person, from animal to person or by consuming contaminated water or food.

In healthy individuals the illness resolves naturally. However, in immuno-compromised individuals such as transplant patients or AIDs sufferers it can be persistent or occasionally fatal.

One of the most commonly recognised routes of transmission to humans has been from contaminated drinking water supplies. The organism forms eggs, which are resistant to chlorination and can remain viable for a considerable time in the environment. Particularly at times of heavy rain, the oocysts are washed from contaminated fields into rivers. Water is taken from many rivers and reservoirs for purification before entering the water supply and, if cryptosporidia are present, can cause outbreaks of illness. This problem was recognised in the Badenoch Report(2) , 1990, and updated in the Bouchier Report 1998.(3) These reports made recommendations about the monitoring and purification of drinking water supplies and closer working between water companies, local authorities and health authorities.

The number of confirmed cases of cryptosporidia in Portsmouth and South East Hampshire has fallen from 45 in 1995 to 15 in 1998 Table 3.5. Most cases of cryptosporidia are ?sporadic’ which means that no links can be identified between them and thus no source for the infection identified. This is unsurprising as many cases of infection may be asymptomatic or go unreported and a proportion of cases are known to be contracted while people are on holiday abroad.

Antibiotic Resistance

There is growing concern about the increasing problem of bacterial resistance to antibiotic therapy. Many bacteria that cause illness in humans are now resistant to several types of antibiotic. This can make some infections particularly difficult to treat, especially when the patient is also immunocompromised, debilitated or elderly. Increasing concern has led the Chief Medical Officer to ask the Standing Medical Advisory Committee to examine the problem of antibiotic resistance in relation to medical prescribing. A report, "The Path of Least Resistance"(4), was published in 1998, the same year that the House of Lords Select Committee on Science and Technology published its report "Resistance to Antibiotics and Other Antimicrobial Agents".(5) One of the most important factors in increasing the prevalence of antibiotic resistance is excessive or inappropriate use of antibiotics. Eighty percent of antibiotic prescribing in humans occurs in general practice, but half of all antibiotic use in the UK is in animals. Much antibiotic use in animals is for prophylaxis and for growth promotion, rather than the treatment of sick animals. A large proportion of all human and animal antibiotic use is considered to be of questionable value.

This section looks at the problem of antibiotic resistance in Portsmouth and South East Hampshire for three common conditions: urinary tract infection, infections with the pneumococcus organism and methicillin resistant staphylococcus aureus (MRSA). It also considers local prescribing practice.

Antibiotic Resistance in Urinary Tract Infection. Urinary tract infections are common in both hospital and general practice and can range in severity from a nuisance to a life threatening illness. The Portsmouth Public Health Laboratory Service confirmed approximately 4,000 cases in hospital and 10,000 cases in general practice in 1997. This under- represents infections in primary care as many cases are treated without sending a urine specimen. Trimethoprim is the local antibiotic of choice and resistance remains stable at about 20%, both in hospital and general practice. As this does not include those cases treated successfully for which no sample was sent, the true level of resistance is likely to be lower. Resistance to amoxycillin occurs in 50% cases and this agent is therefore not recommended locally for the treatment of urinary tract infections. There are many newer and more expensive antibiotics which also have low resistance rates in urinary tract infections. They are useful as a second line treatment and should be reserved for cases where there is proven resistance to a first line agent.

Penicillin Resistance in Pneumococcus Infection. The pneumococcus bacteria causes respiratory and ear infections at all ages, and meningitis in very young babies and older people. Levels of bacterial resistance vary widely and in some countries resistance rates to penicillin reach 50%. In Portsmouth full or partial resistance to penicillin occurs in 7.2% of isolates. This compares with the national figures from surveys of resistance taken every five years of 1.5% in 1990 and 3.9% in 1995(6). Resistance is clearly rising and a further survey is planned for the year 2000. Pneumococcal infection is an important cause of disease and one for which an effective vaccine is available. These increasing levels of resistance may influence the national policy on vaccination which is currently offered only to those with specific conditions such as chronic heart, lung or liver disease, diabetes, chronic renal failure, absent spleen or immunodeficiency.

Methicillin Resistant Staphylococcus Aureus. Staphylococcus Aureus is a bacteria which causes skin, heart, bone and joint infections, and septicaemia. It has traditionally been treated with a penicillin based antibiotic. There are growing problems worldwide with resistance to these antibiotics which can result in serious complications, especially in hospitalised patients. Currently one in four cases of Staphylococcus Aureus isolated from blood in hospitalised patients locally are of the methicillin resistant strain. This is lower than the national average of one in three cases and the same as the regional average(7). The local figures have been stable over the last three years.

Local Antibiotic Prescribing Practice. The total number of antibiotic prescriptions in general practice in Portsmouth and South East Hampshire Health Authority for the period 1997-1999 is shown in Fig 3.2. This shows a slight downward trend as well as a reduction in the peak level of antibiotic prescribing seen during the winter. This is encouraging as it suggests that local prescribing practices are changing and may result in reductions in antibiotic resistance in the future. The use of broad spectrum antibiotics has been blamed for some of the increasing problem of antibiotic resistance and it is important to use the antibiotic most specific for any individual infection. In future it will be important to monitor not only the total amount of prescribing but also the appropriateness of the antibiotics being prescribed.

Local Action. A national campaign to increase public awareness and understanding of the issues surrounding antibiotic use and the problem of growing resistance is to be co-ordinated by the Department of Health. Portsmouth and South East Hampshire Health Authority is developing local initiatives to complement the national campaign. These include developing help sheets for general practitioners, which recommend the best local practice for treating common bacterial disseminated with the help of educational sessions facilitated by primary care prescribing advisers. A system of enhanced surveillance to identify changing resistance patterns to antibiotics will be developed with the microbiology laboratory and community and hospital infection control teams. Better targeting and reduced use of antibiotics is recognised as important if we are to prevent increasing resistance to antibiotics in the future. The use of Prescribing Analysis and Cost (PACT) data to monitor general practitioner prescribing and pharmacy data to monitor hospital prescribing will help identify where prescribing practice needs to be changed.

Immunisation

Immunisation programmes are one of the major public health successes of the last 50 years. Within the next few years, the worldwide eradication of poliomyelitis is likely to be added to the eradication of smallpox achieved 20 years ago. Within the United Kingdom, sustained high uptake rates for immunisation have led to major declines in the frequency of serious childhood infections such as diphtheria, whooping cough and haemophilus meningitis. However, there is a danger of immunisation programmes becoming victims of their own success. As these diseases become so uncommon, public perception of their seriousness falls and concerns about vaccine safety assume greater importance. There have been a number of stories about such concerns over the past 18 months, leading to a decline in uptake rates for some childhood vaccines. This has been seen both nationally and locally. Parent and public confidence in the immunisation programme must be maintained or we may see a repeat of the situation seen 20 years ago when concerns about the safety of whooping cough vaccine led to a major decline in vaccination of children. The resulting epidemics led to over 100,000 cases of whooping cough in the UK. Falls in the number of children currently being vaccinated for other diseases such as measles, mumps and rubella could lead to the recurrence of epidemics of these illness as well.

Infant Immunisation. The infant immunisation programme consists of three series of injections, at two months, three months and four months of age, which are against diphtheria, tetanus, pertussis (whooping cough), polio and haemophilus influenzae (a bacterial infection that can cause meningitis). A single injection against measles, mumps and rubella (MMR) is given at 14 months. The uptake rate is shown in Table 3.8.

For the second year in a row, there has been a decrease in coverage. The decrease compared with 1997 ranges from 0.9% for diphtheria, tetanus and polio, to 2.1% for MMR. This mirrors the national picture, although Portsmouth and South East Hampshire continues to have above average uptake rates compared with national figures.

The decrease follows repeated publicity about possible links between MMR and conditions such as autism and inflammatory bowel disease and unfortunately this adverse publicity has also led to a fall in the uptake rates of the other infant vaccines. Careful review of all the available evidence by many independent experts, both in the UK and abroad, and by the World Health Organisation, has concluded that MMR vaccine is not associated with either autism or inflammatory bowel disease. The Chief Medical Officer has written to all doctors, strongly advising that the current MMR programme should continue. Substantial efforts have been made to provide health professionals and the public within Portsmouth and South East Hampshire with accurate and timely information, and this process will continue.

National data suggests that the fall in uptake rates has now levelled off, but we do not yet have local data to confirm this. It is clear that major efforts will be required to return uptake rates to their former levels.

Table 3.9 shows the pre-school booster immunisation uptake. Pre-school boosters are given at the age of three years and nine months, and do not include pertussis, or haemophilus.

These rates are based on the uptake at time of first scheduling of the booster vaccination and do not include boosters that are given late, for example following postponement due to illness. Final uptake rates are likely to be higher than shown but are significantly lower than the infant immunisations, and have also shown a marked fall over the past couple of years.

School Leaver Vaccinations. The school leaver vaccinations consist of a booster dose of diphtheria, tetanus and polio, given to children between the ages of 14 and 15. Uptake for 1998 was 76%, an increase of almost 5% over the previous year. However, it is likely that the true level of uptake was higher. The reason for this is that there are problems with the collection of this data, as both GPs and School Health Services share the responsibility for vaccination, but do not have a joint information system. A comprehensive child health information system covering birth to school-leaving age has now been developed and came into service on 1 April 1999. This should improve both the uptake and the accuracy of the data.

The school leaver vaccination uptake shows a marked discrepancy between the localities in the district. Thus the uptake in Fareham and Gosport was 92%, 75% in Havant and Petersfield and 68% in Portsmouth City. At present it is difficult to tell whether these reflect true differences or differences in the accuracy of the data. The new system should resolve this issue and there may be implications for primary care groups if these variations are confirmed.

BCG Vaccination. The BCG vaccination protects against tuberculosis. National policy is for universal immunisation of schoolchildren between the ages of 13 and 14. In this age group, vaccination is preceded by a Heaf test, (Table 3.10), to ensure that the children have no evidence of pre-existing immunity.

These figures show a slight fall from last year, though again the lack of a comprehensive child health information system prevents the efficient operation of the recall system. This will be rectified by the time next year’s programme commences. The variation across localities is less evident for this vaccination, though Fareham and Gosport again have the highest uptake.

BCG vaccination may also be given to some new born babies who are at increased risk of developing tuberculosis. These are mainly babies where one or both of the parents originates from an area of the world where tuberculosis is common. The district policy on neonatal BCG was revised in 1997 and there has been a marked increase in the number of neonatal vaccinations given since this change was implemented.

Trends in Vaccine Preventable Disease. Table 3.11 shows the numbers of notifications, in Portsmouth and South East Hampshire, of those infectious diseases against which the childhood immunisation programme is targeted.

Numbers of notifications over the past three years have been fairly stable, apart from measles, which has shown a consistent downward trend for several years, and tuberculosis, where notifications are increasing. The former is almost certainly due to the increases in immunisation rates since the introduction of the MMR vaccine and the school measles/rubella vaccine programme in 1994. Tuberculosis notifications have shown a slight rise nationally since 1990, some of which has been attributed to greater awareness. However, there does seem to be a genuine increase in the number of cases, especially in urban centres, and this may relate to an increasing ethnic minority population, and relatively high rates of homelessness and poverty in these districts.

Though notification of these diseases is a statutory requirement, not all cases will be formally notified. Conversely, not all notified cases are proven. Salivary tests for measles antibody have been routinely performed on notified cases for the last two years, and less than 1% of cases are confirmed. The true decline in cases of measles is thus likely to be even greater than that suggested by these figures.

Conclusion. Before routine immunisation was introduced, a district the size of Portsmouth and South East Hampshire would have had about 1,000 cases of whooping cough and one death each year; 5,000 cases of measles each year and one death every two years; 500 cases of diphtheria and 25 deaths each year; and 40 cases of polio. The last two diseases have been practically eliminated and many of the distressing and sometimes fatal infectious diseases of childhood have almost entirely disappeared as a result of the childhood immunisation programme. Uptake rates for childhood vaccinations in the district remain high, but have fallen over the past two years as a result of inaccurate and adverse media publicity. The rebuilding of public confidence will require a sustained effort by all health care professionals to promote vaccination in the district. This will be supported by the introduction of the comprehensive child health information system, which should increase the uptake rates of immunisation in the school-age group.

Key issues

General

• There is substantial under reporting of cases of notifiable diseases.

Food Poisoning and Cryptosporidium

• There has been a marked increase in the number of food poisoning notifications in the past four years.
• Food poisoning is a significant cause of ill health affecting about one in five of the population each year.
• For every case notified there are at least 100 people affected by food poisoning.
• Local authorities' environmental health departments have a key role in the prevention of food poisoning through their inspection and advisory visits to businesses and their work with individual members of the public.
• There has been a decline in the number of cases of cryptosporidium in the past two years.

Meningitis

• The meningococcal organism is the most common cause of meningitis in Portsmouth and South East Hampshire Health Authority.
• The most important way of reducing death and disability from meningitis is by early detection and treatment.
• There has been an increase in the proportion of cases of meningococcal disease caused by Group C bacteria both nationally and locally.
• The Hib vaccination programme has been effective at preventing meningitis and other life threatening infections caused by haemophilus influenzae.

Antibiotic Resistance

• Antibiotic resistance to many infections is a growing local and national problem.
• Local resistance patterns in urinary tract infection to first line treatment (trimethoprim), remain unchanged.
• Local rates of MRSA infection are below national rates.
• Local resistance to penicillin in pneumococcal infections is greater than the rate seen in the last national survey.
• Early indicators suggest that GP antibiotic prescribing habits may be changing locally with a slight decline recently and lower levels of peak prescribing in the winter.

Immunisation

• Immunisation programmes are one of the major public health successes of the last 50 years. Sustained high uptake rates for immunisation have led to major declines in the frequency of serious childhood infections such as diphtheria, whooping cough, and haemophilus meningitis.
• Uptake rates for childhood vaccines are falling both nationally and in Portsmouth and South East Hampshire, following adverse publicity about the MMR vaccine. There is no convincing evidence that MMR vaccine is associated with either autism or inflammatory bowel disease.

Recommendations

General

• All doctors should be encouraged to report to the proper officer suspected or confirmed cases of communicable diseases.

Food Poisoning and Cryptosporidium

• Local authorities and the Health Authority must continue to work together to provide information and raise public awareness of food poisoning and how it can be avoided.
• The Public Health Department should work closely with environmental health officers to monitor the incidence of food poisoning.
• GPs should be encouraged to send specimens early if they suspect food poisoning.
• Laboratory reports of cases of cryptosporidium to be routinely monitored by the Consultant in Communicable Disease Control.
• Immunocompromised people should be made aware that they should boil their drinking water from whatever source.
• The Consultant in Communicable Disease Control should plan an exercise for a cryptosporidia incident, to involve neighbouring health authorities and water supply companies.

Meningitis

• Information about the symptoms of meningitis and septicaemia will continue to be made available to the public.
• GPs will be reminded of the importance of early intravenous administration of antibiotics to suspected cases of meningitis or septicaemia.
• The Public Health Department will continue to monitor the distribution of cases of meningitis and septicaemia.
• The Communicable Disease Strategy Group will continue to promote awareness of meningitis and septicaemia through educational initiatives aimed at schools, nurseries and higher education institutions.
• The importance of Hib vaccination should be emphasized to parents.

Antibiotic Resistance

• The Public Health Laboratory Service should maintain and strengthen surveillance of local resistance patterns in order to detect changes in antibiotic resistance locally.
• The Consultant in Communicable Disease Control and prescribing advisers should monitor GP and hospital antibiotic prescribing practices and advise on best practices.
• Prescribing advisers will complement the national campaign on antibiotic use through the development of local information material and educational sessions.

Immunisation

• Sustained efforts are required to reverse the decline in immunisation rates to avoid the risk of future epidemics of childhood infectious disease.
• Clear and consistent messages about the effectiveness and safety of childhood vaccinations will be promoted to primary care teams through professional education and Health Authority publications.
• Clear and consistent messages about the effectiveness and safety of childhood vaccinations will be promoted to the public through the media, Health Authority publications, and existing public and patient partnerships.

References:

1. Wheeler J G, Sethi D, Cowden J M, Wall P G, Rodrigues L C, Tompkins D S, Hudson M J, and Roderick P J. Study of infectious intestinal disease in England: rates in the community, presenting to general practice, and reported to national surveillance, BMJ 1999; 318:1046-1050.

2.Badenoch J. Cryptosporidium in water supplies. Report of the Group of Experts; Department of the Environment, Department of Health. London: HMSO 1990

3.Cryptosporidium in water supplies. Third Report of the Group of Experts to: Department of the Environment, Transport and the Regions and Department of Health. Department of the Environment, Transport and the Regions, 1998

4.Standing Medical Advisory Committee Sub-Group on Antimicrobial Resistance. The Path of Least Resistance. Department of Health 1998.

5.House of Lords Select Committee on Science and Technology. Resistance to antibiotics and otherantimicrobial agents. London: HMSO, 1998.

6. Johnson A P, Speller D C E, George R C , Warner M, Domingue G, Efstration A. Prevalence of Antibiotic Resistance and Serotypes in Pneumococci in England and Wales: Results of Observational Surveys in 1990 and 1995. BMJ 1996; 312; 1454-1456.

7. Methicillin Resistance in Styphylococcus Aureus Isolated from Blood in England and Wales: 1994 to 1998. CDR 1999; 9 (8); 65, 68.

Produced by Ann Edmeades, IT Services, Hampshire County Council
for Portsmouth and South East Hampshire Health Authority
© Copyright Portsmouth and South East Hampshire Health Authority 1998
Last Updated 1st September, 1999