It's his second visit to the country since the outbreak was declared in mid-May. The Ebola outbreak reached 3874 cases, including 1751 deaths as of Monday, according to the latest data published overnight by Congo's health ministry. Many health workers have gone on strike to protest lack of payment, although some have reported receiving their payment in recent days. Late detection of cases remains challenging and has been a key contributing factor to the 45 per cent fatality rate, officials say. The 77 new cases reported in the previous 24 hours included 44 deaths, according to the health ministry's update.