单项选择题

Health workers who are HIV positive are banned from performing most surgery or dental treatment in case they cut themselves with their instruments and infect patients with their blood. They can only perform day-to-day tasks, including giving injections; which are considered low risk. But the Department of Health wants to lift the ban because it says the chance of a health worker infecting a patient is "negligible". It has undertaken research suggesting the risk of a patient catching HIV from their doctor, dentist or surgeon is less than one in five million, similar to that of being killed by lightning. Officials say the risk can be further reduced by ensuring any infected member of staff takes medication to reduce their virus count, which means it cannot easily be passed on. There are 110 frontline workers in the National Health Service with HIV who would be affected by the rule change.
Since 2006 all members of staff who deal with patients have had to undergo compulsory blood tests to check whether they have the virus. The Government says there have so far been no recorded cases of patients in Britain catching HIV from a healthcare worker, although it has happened abroad. The Department of Health launched a consultation yesterday on its proposals to lift the ban and in the next few weeks will gather feedback from organizations and the public. Officials are expected to make a final decision next year. They point out that rules in Britain are far stricter compared with elsewhere in the world. In Austria, Belgium, Canada, France and Sweden, for example, it is up to individual employers such as hospitals to decide whether a worker can perform surgery or other tasks.
Under the proposals, HIV-infected health workers would have to be given "combination antiretroviral (抗逆转录病毒的) drug therapy" to reduce the virus count so it could not be transmitted. They would also have to undergo tests to check the virus count was low before they could perform surgery and other procedures. Deborah Jack, chief executive of the National Aids Trust, said, "These recommended rule changes for healthcare workers with HIV are long overdue. Sadly, the UK has lagged behind other countries in addressing this issue.\
What does the author mean by saying "... similar to that of being killed by lightning" (Line 7, Para. 1)（）