Yellow Fever Virus: Diagnostics for a Persistent Arboviral Threat

Abstract

Yellow fever (YF) is the prototypical hemorrhagic fever and results from infection with yellow fever virus (YFV), which is endemic to regions of Africa and South America. Despite the availability of an effective vaccine, YFV continues to cause disease throughout regions where it is endemic, including intermittent large outbreaks among undervaccinated populations. A number of diagnostic methods and assays have been described for the detection of YFV infection, including viral culture, molecular testing, serology, and antigen detection. Commercial diagnostics are not widely available, and testing is generally performed at a small number of reference laboratories. The goal of this article, therefore, is to review available clinical diagnostics for YFV, which may not be familiar to many practitioners outside areas where it is endemic. Additionally, we identify gaps in our current knowledge about YF that pertain to diagnosis and describe interventions that may improve YFV detection.

Late-Relapsing Hepatitis after Yellow Fever

“…Nevertheless, the results so far suggested YFV persistence in the liver up to three months after the onset of YF. The absence of RNAmia (indicating the lack of viremia), and the presence of anti-YFV IgM and IgG from the 8th day of the first symptoms forward are consistent with the expected pattern for YF, with IgM appearing after one week of disease onset [1] and IgG levels rising a few days later [13].…”

Inactivation of yellow fever virus with amotosalen and ultraviolet A light pathogen‐reduction technology

“…In 45% of the YF cases, symptoms may develop 3 to 6 days after infection. Wild‐type YFV causes a pansystemic viral disease with viremia approximately 8 log GE/mL and symptoms may develop after or concomitantly with peak viremia . Therefore, asymptomatic or presymptomatic infected blood donors could present at the blood center and be allowed to donate blood while in the ramping phase of viremia.…”

“…Wild-type YFV causes a pansystemic viral disease with viremia approximately 8 log GE/mL 28 and symptoms may develop after or concomitantly with peak viremia. 28 Therefore, asymptomatic or presymptomatic infected blood donors could present at the blood center and be allowed to donate blood while in the ramping phase of viremia. Assuming YFV is similar to that reported for other flaviviruses, which have a 2 to 3 log ratio of infectious particles to genome equivalent, 29,30 a PR system with inactivation capacity greater than 5 logs as measured by infectivity assays is preferable.…”

Memory T Cells in Flavivirus Vaccination

“…YFV is endemic to tropical and subtropical regions of South America and Africa. Although a majority of human YFV infections are asymptomatic, severe YF occurs in about 12% of infected individuals and may manifest with jaundice, hemorrhage, and multisystem organ failure [67]. The YFV 17D live-attenuated vaccine was developed by Max Theiler and colleagues in 1930s, for which he won the Nobel Prize in 1951.…”