Monkeypox contacts: a puzzling problem.

When it emerged that two people infected with monkeypox had travelled by plane through one of the world's busiest airports, a media storm arose, with irresponsible headlines and exaggerations of risks for others in the UK and across the globe.

The two patients—currently recovering in specialist units in London and Liverpool, UK—probably contracted the infection, which produces symptoms such as fever, headache, malaise, and the typical smallpox-like vesicular rash, from animals in Nigeria, where there is an ongoing outbreak of the virus. The Nigeria Centre for Disease Control has recorded 262 suspected cases of monkeypox since the outbreak began in September, 2017, including 113 confirmed cases and seven deaths. The Nigerian outbreak is likely to be the result of a local zoonotic spillover event from the virus' natural hosts—rodents. The disease, caused by a virus of the Orthopox genus, is usually self-limiting—although it has a mortality rate of 1–10%.

Human-to-human spread is rare, but cases have been recorded after prolonged, close exposure to infected individuals. The two infected patients had travelled from Nigeria's capital Abuja on separate flights—one coming indirectly into Heathrow—and then used further modes of transport to arrive in their final destinations in the UK. 213 668 passengers pass through the airport every day, and 76 600 employees work within the boundaries of the 2 227 acre site.

Public Health England (PHE) is currently monitoring anyone who came in close contact with the patients including health-care workers who were not wearing personal protective equipment, passengers on the planes seated three rows in front or behind the patients, and anyone who had sustained contact with the patients in a domestic or work setting. They have been asked to look out for symptoms of the illness and to talk with their designated PHE lead if any signs occur.

Clearly, the risk of outbreaks from emerging zoonotic infections remains an important threat in the modern era of extensive, rapid interconnectedness. However, in the media fallout, PHE avoided being caught up in hyperbole and has sensibly undertaken a balanced approach to a puzzling problem.

For more about the UK cases of monkeypox see https://ncdc.gov.ng/news/152/re%3A-monkeypox-cases-in-the-united-kingdom