A team of Chinese experts arrived in Tehran Saturday to help combat the deadliest outbreak of the coronavirus outside China, as the number of confirmed cases in Iran jumped more than 50% overnight and Iranian authorities complained of a shortage of supplies needed to contain the rapidly spreading illness.

Iran’s health ministry said Saturday that 593 patients had tested positive for coronavirus. Nine more people in Iran have died from the illness, bringing the total number of fatalities in the country to 43, according to the...