Google Earth Typhoid Reveal Disease Outbreak Secrets

British researchers have found a new way to track the spread of diseases in locations that lack traditional mapping support.

Google Earth has become a scientific tool for tracking in areas that do not allow health workers to record infections that are tied to street names and house numbers. Researchers from the British Wellcome Trust used Earth and GPS data to pinpoint the presence of Typhoid in Kathmandu, Nepal, which adds to the ability to track mutations of a disease via DNA sequencing.

The researchers found that the typhoid infection rate is not related to the density of the population. Instead, the study showed that the likelihood of infection increased the closer people lived to water spouts and the lower the geographic elevation. Typhoid, which is caused by the two bacteria salmonella typhi and salmonella paratyphi, is believed to be connected to faecal contamination of ground water during the monsoon time. The researchers discovered a particular strain of the salmonella paratyphi was spreading downstream from the focus area, which indicated that people at lower elevations are at higher risk to contract typhoid.

When the scientists analyzed the bacteria and their variations and their appearance, they found that typhoid infections are transmitted predominantly through the environment and not through people. They concluded that "improvements in infrastructure are fundamental to the control and elimination of typhoid."

As long as people are exposed to poor water quality, vaccines may have little effect and there is little chance that a community can get rid of the infection carriers. "Without integrating improvements in infrastructure alongside other control measures such as diagnosis, treatment and vaccination, it is unlikely that typhoid can be adequately controlled in places like Kathmandu in the long-term," they said.