How rare is London's deadly legionnaires’ disease outbreak?

How rare is London's deadly legionnaires’ disease outbreak?

As London’s legionnaires’ disease outbreak climbs to 66 confirmed cases, including two deaths, an infectious disease expert says the city’s caseload is far beyond what he’d expect in a typical year. With the outbreak's source still unconfirmed, reporter Adshayah Sathiaseelan reports on the rarity of the situation and what may be behind it.