the World Health Organization applied a global influenza surveillance network. During the 1994 plague in India, many people were quarantined. Vessels and aircraft carrying passengers were fumigated. In the SARS epidemic, thousands of Chinese people were quarantined and checkpoints to take temperatures were set up. Moving infected patients to isolation wards and home-based self-quarantine of people potentially exposed was the main way the Western African Ebola virus epidemic was ended in 2016; members of the 8th WHO Emergency Committee criticised international travel restrictions imposed during the epidemic as ineffective due to difficulty of enforcement, and counterproductive as they slowed down aid efforts. The People's Republic of China has employed mass quarantines – firstly of the city of Wuhan and subsequently of all of the Hubei province (population 55.5 million) – in the coronavirus disease 2019 pandemic. After a few weeks, the Italian government imposed lockdowns for the entire country (more than 60 million people) in an attempt to stop the spread of the disease there. India quarantined itself from the world for a period of one month. Most governments around the world restricted or advised against all non-essential travel to and from countries and areas affected by the outbreak. By late 2020, the virus had already spread within communities in large parts of the world, with many not knowing where or how they were infected. Signals and flags Plain yellow, green, and even black flags have been used to symbolise disease in both ships and ports, with the colour yellow having a longer historical precedent, as a colour of marking for houses of infection, previous to its use as a maritime marking colour for disease. The former flag used for the purpose was the "Lima" (L) flag, which is a mixture of yellow and black flags previously used. It is sometimes called the "yellow jack" but this was also a name for yellow fever, which probably derives its common name from the flag, not the colour of the victims (cholera ships also used a yellow flag). The plain yellow flag ("Quebec" or Q in international maritime signal flags) probably derives its letter symbol for its initial use in quarantine, but this flag in modern times indicates the opposite—a ship that 'requests free pratique', i.e. that declares itself free of quarantinable disease, and requests boarding and routine port inspection. Ships in quarantine today would fly either the Q flag alone, meaning