Coughs and sneezes spread diseases, but some people pass on more infections than others

Global Stop TB Partnership

Research published in Nature shows that for infectious diseases such as SARS, measles and Ebola, a minority of individuals are responsible for most new cases.

As Alison Galvani and Robert May explain in an accompanying article, treating only these 'superspreaders' could halt disease outbreaks sooner, whilst treating fewer people than if conventional measures were used.

Galvani and May say such 'heterogeneous diseases' are less likely to cause epidemics than infections that everyone is equally likely to pass on. But the researchers warn that if such diseases are left unchecked and do give rise to epidemics, they are more likely to be "explosive".

The most heterogeneous diseases include schistosomiasis (bilharzia), HIV/AIDS and malaria, for which one-fifth of the population is responsible for more than 80 per cent of disease transmission.