The governments in both the movie and novel never told the public how many people had died from the virus to stop people from panicking and causing mass hysteria. In Contagion social media was a big threat to the government because of how information could be shared from 1 person to millions and since this information was faulty it caused unnecessary panic, but as for the Hot Zone having someone spreading false information would have been way harder because there wasn't really social media back then. In Contagion the government got backed into a corner and had to end up telling the population that there was a pandemic, but in the Hot Zone they never told anyone about it until years after the pandemic was