The growing problem of whooping cough was reported at a meeting in Milan of the European Congress of Clinical Microbiology and Infectious Diseases. Scientists said one reason why the disease is appearing in greater numbers is possibly because an increasing number of teens, adults and elderly people who have the disease, but don't know it, are unknowingly spreading it to infants who have not been vaccinated.
Another speculation is that the immunisations wear off after a few years and, after decades of use, the bug may have become resistant to the vaccine anyway.
The disease, caused by the bacteria Bordetella pertussis, is usually not a danger in adults but can be fatal to infants and was, for many years, one of the most common causes of infant mortality, until a vaccine was introduced in the 1940s. - (SAPA)