2016 Angola and DR Congo yellow fever outbreak a 32-year-old male Chinese citizen who had been in Angola had developed yellow fever on return. The case was the first imported yellow fever case in China in history. Yellow fever has never appeared in Asia even though the mosquito vector is present. Additional cases were later reported in people who first had symptoms while in Luanda. ProMED-mail moderator Jack Woodall warned that "spread could make the Ebola and Zika epidemics look like picnics in the park!" and that "international action should start now." Chinese authorities strengthened thermal imaging at airports to detect passengers with elevated body temperatures. A Chinese
Yellow fever titer (compared to an earlier sample) can confirm yellow fever. Together with clinical symptoms, the detection of IgM or a four-fold increase in IgG titer is considered sufficient indication for yellow fever. Since these tests can cross-react with other flaviviruses, such as dengue virus, these indirect methods cannot conclusively prove yellow fever infection. Liver biopsy can verify inflammation and necrosis of hepatocytes and detect viral antigens. Because of the bleeding tendency of yellow fever patients, a biopsy is only advisable "post mortem" to confirm the cause of death. In a differential diagnosis, infections with yellow fever must be distinguished from