Yellow fever In 1873, Shreveport, Louisiana lost 759 citizens in an 80-day period to a Yellow fever epidemic, with over 400 additional victims eventually succumbing. The total death toll from August through November was approximately 1,200, In 1878, about 20,000 people died in a widespread epidemic in the Mississippi River Valley. That year, Memphis had an unusually large amount of rain, which led to an increase in the mosquito population. The result was a huge epidemic of yellow fever. The steamship "John D. Porter" took people fleeing Memphis northward in hopes of escaping the disease, but passengers were not allowed to disembark
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