Stock markets fell back from record highs on Thursday as the death toll from coronavirus leapt after a change in how infection rates are measured in China.

Officials in Hubei, the Chinese province at the centre of the outbreak, reported another 14,840 cases and 242 deaths overnight.

It takes the total death toll to an estimated 1,350, sending stock markets tumbling once again amid fresh fears over the potential scale of the outbreak.

Markets had reached record highs in Europe on Wednesday, amid hopes Chinese authorities’ tough quarantine measures were helping to contain the spread of the flu-like virus. China had reported its lowest number of new cases in a fortnight on Wednesday, according to Reuters.

But health authorities in Hubei announced the spike in reported cases after they began using quicker CT scans to diagnose the virus rather than genetic tests that can take several days.

READ MORE: How the coronavirus outbreak is hitting firms around the world

The pan-European STOXX 600 index (^STOXX), which tracks the continent’s top 600 listed companies, dropped 0.4%.

Germany’s DAX (^GDAXI) dropped by 0.3%, while France’s CAC 40 (^FCHI) was down 0.2%. The FTSE 100 (^FTSE) in London fell further, sinking 0.9% as announcements from Centrica (CNA.L) and Barclays (BARC.L) also weighed on shares.

In Asia overnight, China’s SSE Composite Index closed down 0.7%, Hong Kong’s Hang Seng Index (^HSI) slid by 0.3%, and Japan’s Nikkei (^N225) lost 0.1%.

“Doubts are being raised as to whether the Chinese government will be able to contain the spread of the virus in the very near future. Accordingly, the latest number of new infections is a cause for concern,” said Marc-Andé Fongern, head of FX research at MAF Global Forex.

US stocks also looked set for a lower open. Dow Jones futures slid 0.5% (YM=F), the S&P 500 looked set to lose 0.4% (ES=F), and Nasdaq futures slid 0.6%.