Respiratory diseases

The respiratory team covers influenza, tuberculosis (TB) and Legionnaires’ disease. Issues associated with influenza include surveillance and public health preparedness/response for pandemic, avian and seasonal influenza viruses.

Current work includes surveillance, prevention and control of the following diseases: TB, seasonal/pandemix influenza and Legionnaires’ disease.

Tuberculosis

Tuberculosis (TB) is an infectious disease caused by the bacteria Mycobacterium tuberculosis, which is spread by airborne droplets. The risk of infection depends upon duration of exposure, the instensity of the exposure, and the immune status of the person exposed. The immune system clears the bacteria immediately in more than 80% of people exposed. In a small proportion of people who have been infected, the bacteria are walled off and remain dormant but viable. This is called latent TB. It is estimated that 5-10% of those with latent TB will develop active TB during their lifetime. The most infectious form of TB is pulmonary TB, particularly smear positive cases where TB bacilli can bve seen on direct microscopic examination of the sputum. Left untreated, it is estimated that each person with active TB will infect on average between 10 and 15 people each year.

For further information on TB, see Epidemiology of tuberculosis in Northern Ireland annual report 2008

For surveillance information on TB, see Communicable Disease Surveillance Centre Northern Ireland

General information on TB.pdf

Notification and data collection form for Enhanced Tuberculosis Surveillance.docx

Influenza

Influenza or 'flu' is a respiratory illness associated with infection by influenza virus. Symptoms frequently include headache, fever, cough, sore throat, aching muscles and joints.

Influenza occurs most often in winter and usually peaks between December and March in the northern hemisphere. There are two main types that cause infection: influenza A and influenza B. Influenza A usually causes a more severe illness. The influenza virus is unstable and new strains and variants are constantly emerging, which is one of the reasons why the flu vaccine should be given each year.

For most people, influenza infection is just a nasty experience, but for some it can lead to more serious illnesses. The most common complications of influenza are bronchitis and secondary bacterial pneumonia. These illnesses may require treatment in hospital and can be life threatening, especially in the elderly, asthmatics and those in poor health.

For further information on seasonal flu, including surveillance arrangements and the seasonal flu bulletin see the Public Health Agency resource Flu Aware NI

Legionellosis

Legionellosis is caused by the bacterium Legionella pneumophila and includes pneumonic form (Legionaires disease) and the non-pneumonic form (Pontiac Fever). Legionaires disease presents as pneumonia, with a dry non-productive cough and severe flu-like symptoms. It can occur sporadically as an uncommon cause of community-acquired pneumonia, or as cases associated with environmental sources such as hospitals, hotels and factories.

Further information on legionnaires disease see the health protection surveillance.