More than 422,000 Rohingya have fled to Bangladesh from Rakhine State in Myanmar following an escalation in violence on 25 August. The most recent wave of Rohingya refugees has added to the hundreds of thousands of Rohingya who fled across the border in previous years. Most of the newly arrived refugees have moved into makeshift settlements without adequate access to shelter, food, clean water, or latrines. With little potable water available, people are drinking water collected from paddy fields, puddles, or hand-dug shallow wells which are often contaminated with excreta. At MSF’s clinic in Kutupalong, 487 patients were treated for diarrhoeal diseases between 6 and 17 September. Food security in and around the settlements is also incredibly fragile: newly arrived refugees are completely reliant on humanitarian aid, prices in the market are skyrocketing and the lack of roads is compromising access to the most vulnerable populations. A massive scale-up of humanitarian assistance in Bangladesh is needed to aid the Rohingya refugees and avert a wider public health disaster. Photographer: Antonio Faccilongo