Respiratory infections are common both at home and abroad and frequently affect people while travelling. Certain situations which may be encountered when travelling, and certain infections, place the traveller at some increased risk of a respiratory infection.

10.2  Acute respiratory infections

Some travellers spend considerable periods in crowded conditions or communal living which may increase the risk of acute respiratory infections such as colds, influenza and bronchitis. Most are self-limiting virus infections for which there is no specific treatment. If symptoms persist or worsen, medical attention should be sought. Practitioners should be aware that respiratory pathogens acquired abroad may have unusual antimicrobial resistance patterns.

10.3  Influenza and pneumococcal infections

Influenza infection occurs throughout the world mainly in winter (it should be remembered that in the southern hemisphere this is during the summer months of the northern hemisphere). In the tropics, influenza activity is not seasonal. For most travellers no specific protection against influenza is recommended and treatment should be symptomatic. Influenza immunisation before travel should be considered for individuals for whom annual influenza immunisation is recommended in the UK, such as those (of any age) with certain chronic underlying diseases and those aged 65 and over.

The risk of pneumococcal infection is increased in certain groups and increases with age; high altitude may add to the risk. Immunisation is advised for those at increased risk in accordance with the recommendations in Immunisation against Infectious Disease.

10.4  Legionnaires' disease

Legionnaires' disease is an uncommon form of pneumonia or severe chest infection which has a significant mortality, particularly among middle aged or elderly adults. It may be contracted anywhere in the world. Both sporadic cases and outbreaks of legionnaires' disease have been reported among holiday makers who have stayed in hotels and apartment blocks, particularly around the Mediterranean. Although the risk for any individual is extremely small, the diagnosis should be considered in travellers who develop a respiratory illness, particularly pneumonia, during or on return from their travel, so that appropriate treatment can be instituted promptly. No preventive measures against acquiring legionnaires' disease are available to the individual.

Use of a rapid diagnostic test (e.g. detection of antigen in urine) will enable rapid and appropriate antibiotic treatment to be given, thus reducing the risk of severe illness and death from this disease.

10.5  Tuberculosis

Tuberculosis (TB) is one of the major global public health challenges. The World Health Organization estimates that one third of the world's population is infected with TB, and it is the major cause of death from a single infectious agent among adults in the developing world. There has been some increase in TB in parts of the industrialised world.

In many countries of Africa and Asia, infection with HIV has further increased morbidity and mortality from TB: TB is responsible for about 40 per cent of AIDS-related deaths in Africa. Drug resistant TB is increasing in many areas of the world.

Among travellers from industrialised countries, the families of migrants returning to visit relatives abroad are particularly at risk. The risk for other travellers is limited as transmission of the infection usually requires prolonged close contact.

Regions of the world can be categorised based on the incidence of cases of tuberculosis reported to the World Health Organization. The incidence of tuberculosis is generally high in Africa, Asia and South America and low in industrialised countries. Some countries within global regions may, however, have incidence rates that differ substantially from that seen in the rest of their region. For countries in low risk regions, with an incidence rate of up to 40 per 100,000 population, no specific recommendation for BCG immunisation is made for travellers. For countries defined as high risk (incidence rate over 40 per 100,000 population), BCG is recommended for visits longer than about a month, particularly if living or working with the local population. (See under disease risks for each area for the risk for particular countries).

BCG should only be offered to those not previously immunised and who have a negative tuberculin skin test (see Immunisation against Infectious Disease for further details).