Saudi Arabia said yesterday the total number of cases of Middle East Respiratory Syndrome (Mers), an often deadly new disease, had nearly doubled in the kingdom in April with 26 further infections reported on Tuesday and Wednesday.

International concern about Mers is acute because Saudi Arabia is expected to receive large numbers of foreign pilgrims during the fasting month of Ramadan in July, followed by millions more for Islam’s annual haj pilgrimage in October.

Although the World Health Organisation (WHO) has said the disease is difficult to pass between humans, most of the cases reported in Saudi Arabia so far appear to have been transmitted between people, rather than from animals.

Seven of the new cases were in Jeddah, four in Mecca, 10 in Riyadh, two in the northern town of Tabuk and one each in Hafr al-Batin near Kuwait and Najran near Yemen. Two people, who had previously been confirmed as suffering from the disease, died.

The new cases have taken the total number of confirmed infections in Saudi Arabia to 371, a jump of 89 per cent during the month of April. Most of the new infections last month came in an outbreak in three hospitals in Jeddah.

Of people who caught the disease in Saudi Arabia, 107 have died since it was identified two years ago.