Infectious diseases are caused by micro organisms which can spread from one person to another. These micro organisms include:
- viruses which cause infections like measles and influenza;
- bacteria which cause infections like impetigo and meningitis ;
- parasites like head lice and scabies.
The way an infectious disease spreads between people depends on the disease. Examples are direct contact with the infected person, the environment, through the air, contaminated food, and through exposure to infected blood or body fluids.
Deaths due to infectious diseases have declined, in part due to improvements in sanitation, but also the introduction of vaccination programmes and improvements in medical treatments. However, the burden of infectious diseases remains high. Infections remain a major cause of death in the very young and in the elderly, especially for those with pre existing conditions.
Infectious diseases are mostly preventable, and therefore the burden of infectious diseases on individuals, communities, health services, and the economy is also preventable. Primary prevention of some infectious diseases can be achieved through vaccination. In addition, basic precautions help to reduce the spread of an infectious disease, for example:
- "Catch it, bin it, kill it" helps control the spread of colds and influenza;
- exclusion from school, nursery or the workplace may halt the spread of infections such as viral gastroenteritis;
- identification and screening of contacts may help prevent further spread of some infectious diseases, like Tuberculosis.
Further information on specific infections, visit: A to Z of infectious diseases .
The local picture
Weekly data is published for several infectious diseases notifiable to Public Health England ( Notifiable diseases and causative organisms: how to report ) . The published data only reports notified cases plus some laboratory notifications and is not considered an accurate measure of overall incidence. It is acknowledged that many cases may not be notified or others not denotified on confirmation of another cause.
Notifications of infectious diseases in Calderdale are generally low when compared to neighbouring areas. Below are a few key infections:
Rate per 100,000 population of notification of infectious diseases in West Yorkshire authorities for 2015 unless stated
|Authority||Tuberculosis (TB): 3 year average 2012-14||Hepatitis C: 2014||Measles||Mumps||Rubella||Pertusis (whooping cough)||New cases of Human immunodeficiency virus (HIV)|
|Yorkshire and the Humber||10.6||28.4||2.1||14.7||1.2||6.2||5.5|
Mortality associated with infectious diseases, including influenza
For England, the rolling average mortality rate for infectious diseases is 10.5 per 100,000 population. In Calderdale this was 9.5 per 100,000 population.
Inequalities data relating to the incidence of infectious diseases is limited but may be published in PHE annual reports where available (eg TB, Hepatitis C) and the Public Health profiles website.
However, there are many diseases that are more prevalent among certain groups eg:
- Hepatitis C is more prevalent among males aged 25-44 years of age and people who inject drugs;
- HIV is more prevalent among men who have sex with men;
- complications of influenza are more prevalent among older people, infants, pregnant women and people with long term conditions.
Where data is available, immunisation rates are lowest in the most deprived areas eg Measles, Mumps and Rubella (MMR).
Infectious diseases are managed through Primary Care (General Practitioners (GP) practices and pharmacies), acute hospital services, sexual health and drug services and tertiary services (eg Leeds Infectious Diseases Unit). Support and advice is available to providers of health and social care, community groups, schools and members of the public via Public Health England and the Calderdale Council's Infection Prevention and Control Team, based in the Public Health Directorate.
In addition, Calderdale has a dedicated TB service commissioned by the Clinical commissioning group (CCG) and provided by Calderdale and Huddersfield NHS Foundation Trust (CHFT). The service is delivered in line with the NICE guidelines ( Tuberculosis ) with the needs of the population in mind.
No user views have been collected over the general management of infectious diseases. However, patient feedback information is available for the different providers of services and may be included in the disease specific annual reports.
Calderdale has a low incidence of HIV. However, the rate of late diagnosis of HIV in Calderdale, whilst improving, remains higher than that of England and of the region, suggesting the needs of individuals with undiagnosed HIV are not being met. Actions are being taken to increase knowledge, understanding and improve access to testing.
The Yorkshire and Humber report on Hepatitis C (Public Health England, 2015: Hepatitis C in the UK ) was discussed at the Calderdale Health protection assurance group. Yorkshire and Humber as a whole have the highest rate outside London, but Calderdale remains a low rate area. A gap in knowledge is the prevalence in the South Asian population who account for 14% of specimens tested in Yorkshire and Humber, but 17% of positive results, therefore is the population under tested or is testing better targeted.
In line with the national trend, the uptake of influenza vaccine dropped last year in most of the target groups. This was considered to be related to the negative publicity in 2014/15 regarding the vaccine match to the circulating strains of flu. Actions are being taken to ensure the public are provided with accurate and consistent messages and improved access to vaccination through the additional provision via pharmacies across West Yorkshire.
National results of antenatal screening for hepatitis B, HIV and syphilis in England and Yorkshire and Humber shows the uptake of screening for all infections remains high (>95%). A gap in knowledge and assurance is the local data on uptake and outcomes.
Projected future need
The key change to impact on the incidence of infectious diseases is travel and migration. Not only can this affect the incidence of diseases such as TB and Hepatitis B, but can affect the risk of pandemic infections. Systems are in place to support travel health, review health needs of new entrants and to ensure people receive the vaccinations they need to prevent the spread of vaccine preventable infections.
Key considerations linked to the known evidence base (what works?)
TB new arrival screening uses Interferon-Gamma Release Assay (IGRA) as a first line for testing, considering the group to be a difficult to engage community, unlikely to attend for two appointments in one week which is required by the National Institute for Health and Care Excellence (NICE) first line treatment. This difference is captured in the Calderdale TB service specification.
NICE guidance is in development to inform increasing the uptake of influenza immunisation.
There are NICE guidelines associated with infectious disease management (this is not an exhaustive list):
- PH21: Immunisations: reducing differences in uptake in under 19s ;
- CG102: Meningitis (bacterial) and meningococcal septicaemia in under 16s: recognition, diagnosis and management ;
- NG33: Tuberculosis ;
- PH34: HIV testing: increasing uptake in men who have sex with men ;
- CG139: Healthcare-associated infections: prevention and control in primary and community care ;
- QS19: Meningitis (bacterial) and meningococcal septicaemia in children and young people ;
- PH43: Hepatitis B and C testing: people at risk of infection ;
- CG165: Hepatitis B (chronic) : diagnosis and management .
References and further information
- Public Health England, 2015: Hepatitis C in the UK ;
- Public Health England, 2015: Notifiable diseases and causative organisms: how to report .
- A to Z of infectious diseases ;
- Public Health profiles .
More information on health can be found in Further resources .
Gill Manojlovic, Head of Infection prevention and control, Public Health, Calderdale Council (22nd November 2016).