"You can prevent diarrhoea, you can prevent measles, you can even prevent malaria to some extent. But we've never been able to stop kids getting chest infections. They hit them like a truck." - MSF field doctor, Thailand Chest infections, of which pneumonia is the most serious form, are usually one of the five major causes of death in any emergency situation. The others are diarrhoea, malnutrition, measles and malaria. Even in non-emergency situations, chest infections are probably second only to diarrhoea in terms of the number of deaths they cause in developing countries. The most serious type of chest infection is bronchopneumonia. It affects young children, and may start as a simple cold. Then the lungs become affected and the child has a high fever, cough, and can be seen to be breathing rapidly. Listening to the chest with a stethoscope one hears sounds like sandpaper on wood - these are called crepitations, and are quite distinct from the gentle breath sounds of a normal chest. Any child with bronchopneumonia is at serious risk of death.