Serious respiratory illnesses

Legionnaires’ disease

The Legionnaires involved have nothing to do with the French Foreign Legion. The disease is named after a group attending an American Legion Convention in Philadelphia in 1976 who developed a mystery respiratory illness. Despite the headlines of ‘Killer virus’ that usually follow such dramatic events, the cause was eventually identified as a newly recognised strain of bacteria now called Legionella pneumophila. It had not been identified before because it could not be cultured in the laboratory by the established methods. It is now known that it exists naturally in water and mud in lakes and rivers, and can grow in the water systems of buildings.

It has caused outbreaks after infecting the air conditioning and water systems of hospitals and office blocks in the UK and hotels in several western countries. It can occur anywhere in the world.

Clusters of cases of pneumonia in returning travellers have been associated with hotels and apartment blocks in various areas surrounding the Mediterranean. The shower systems are usually implicated.

Continuous chlorination of the water and raising the temperature of all the circulating water to keep it hot usually controls the growth of bacteria. When this is done as a precaution, you need to be careful not to get scalded when using the hot water tap.

A person who has the disease, caused by inhalation of the organism, will have the symptoms of pneumonia with cough, shortness of breath, and often fever and chest pain.

Sometimes diarrhoea or vomiting occurs early on. It is now treatable with antibiotics and so is usually only a serious danger to infirm individuals or those whose immune system is unable to function well. However, it is worth considering, or asking your doctor to consider it as a possible diagnosis, if you have symptoms of pneumonia after your holiday. See also SARS below.

SARS

Severe acute respiratory syndrome (SARS) was first recognised in March 2003. Cases arose in Guangdong Province in southern China and by 13 May there were 7,548 probable cases including 573 deaths from 29 countries. Recommendations to restrict travel (an extremely unusual step) to certain parts of China and other countries with evidence of spread were issued by the WHO, followed by the UK authorities. Meanwhile only a handful of cases were imported into the UK with virtually no spread of disease from these cases. There was a

potential for many countries to be affected and for there to be serious health and economic consequences. Health facilities, even in developed countries, can be severely stretched by the requirement for isolation and barrier nursing, so in developing countries there was even more potential for hospitals to be overwhelmed (see ‘Avian influenza’ below).

The cause of SARS was unknown, although it is thought to be a new variety of the normally mild coronavirus. The symptoms are high fever and a cough or difficulty breathing. Despite the highly contagious spread from just a few people who took the virus from country to country initially, and the rapid spread to medical staff in hospitals and to other family members in the home setting, it appeared much less contagious in most other situations, including casual contact in streets and airports.

It seems sensible that travellers are still aware of the symptoms of SARS especially if outbreaks recur. Vigilance has to be maintained. In time, there may be a vaccine.

Avian influenza

Worries about a pandemic of avian (bird) influenza had overtaken concerns about SARS by the summer of 2005. This strain of flu, which originally affected birds and chickens in Hong Kong, China, Thailand, Vietnam and other parts of south-east Asia, by early 2008 has been reported in 33 countries. Although most infections have been in birds, by 22 February 2008 366 humans had caught the infection as a result of close contact with infected birds, and 232 died. It has the potential to cause a global pandemic if it spreads between individuals in the human population. Without an effective vaccine and limited treatment options, medical facilities in both developing and developed countries would be stretched to the limit (see ‘SARS’ above). Meanwhile travellers are advised to take the following precautions:

• Avoid visiting live animal markets and poultry farms
• Avoid contact with surfaces contaminated with animal faeces
• Do not eat or handle undercooked or raw poultry, egg or duck dishes
• Do not attempt to bring any live poultry products back to the UK
• Do not pick up or touch dead or dying birds
• Exercise good personal hygiene with frequent hand washing.

Travellers are not advised to carry antiviral drugs and to date there have been no cases in travellers.

In the event of a sudden increase in cases in the UK or before travel you should refer to the Nathnac (National Travel Health Network and Centre) and Department of Health websites (see ‘Useful information’).

There are vast international efforts to produce a specific vaccine that are hampered by the ability of the virus to mutate. The current flu vaccine is not effective against avian flu.