Donor shortage threatens rare-blood carriers

Only a small number of people in China have rhesus negative blood, and a lack of supplies can be potentially life-threatening if they need an urgent transfusion. Zhou Wenting reports from Shanghai.

Xie Yingfeng recently quit his job to devote himself to an NGO that helps people with a rare blood type find donors who could potentially save their lives.

There are four human blood types: A, B, AB, and O. Each has a rhesus factor, either positive or negative. Generally, people with rhesus negative blood can only receive transfusions of their own type, while rhesus positive carriers can receive blood from both positive and negative donors.