MAR 01, 2018 12:44 PM PST

Yellow Fever Persists in Urine and Semen

WRITTEN BY: Kara Marker
Scientists found evidence of the yellow fever virus in urine and semen samples almost one month after one São Paulo patient became infected. The problem? Scientists thought that a person infected with yellow fever was no longer contagious after ten days.
The yellow fever virus. Credit: CDC Public Health Image Library
This discovery means that a person infected with the virus is capable of passing the infection to others longer than scientists thought. The present study is, in a way, a follow-up to another study where researchers found dengue virus and Zika virus in urine and semen samples in infected patients. For the Zika virus, scientists observed the pathogen persisting in semen for months.
"This detection is a matter for serious concern, above all because it suggests that the transmissibility period for yellow fever virus may be longer than expected in the case of an acute infection,” explained study author Paolo Zanotto.
The patient involved in the discovery is a 65 year-old Sao Paulo individual, who never entered the toxic phase of the disease. Researchers found viral RNA from yellow fever virus, usually tested for using blood samples, in urine and semen samples 15 and 25 days after the individual’s yellow fever symptoms first began.
Yellow fever, like Zika and dengue, is transmitted to people through the bite of a mosquito carrying the virus. Symptoms usually go away three or four days after they begin and include fever, chills, fatigue, headache, muscle pain, nausea, and vomiting.
Scientists still need to test more patients to further understand what this discovery means for yellow fever and its transmission. They will need to find out how often the virus persists for multiple weeks and just how long it can stay in the human body. Being able to understand these components of yellow fever infection will help scientists improve diagnostics for the disease.
Current methods for diagnosing yellow fever involve certain tests that look for viral RNA in the blood. One test, called ELISA, measures the blood levels of immunoglobulin M, a type of antibody produced in the immune response against pathogens.
However, over half of people infected with yellow fever never show symptoms, which often prevents them from getting tested. Scientists from the present study offer a non-invasive diagnostic option: detection of the virus in urine.
"Detection of the virus in urine has been used to confirm infection by other flaviviruses, such as West Nile, Zika and dengue. In the case of dengue, this method won't become standard yet because we aren't sure how many infected people do in fact have the virus in their urine,” Zanotto explained. “This must now be investigated.”
The present study was published in the journal Emerging Infectious Diseases.


About the Author
  • I am a scientific journalist and enthusiast, especially in the realm of biomedicine. I am passionate about conveying the truth in scientific phenomena and subsequently improving health and public awareness. Sometimes scientific research needs a translator to effectively communicate the scientific jargon present in significant findings. I plan to be that translating communicator, and I hope to decrease the spread of misrepresented scientific phenomena! Check out my science blog:
You May Also Like
APR 24, 2018
APR 24, 2018
Synthetic Retinoid Shows Promise for Inhibition of Cancer Cells
Researchers studied the potential use of a synthetic retinoid, WYC-209, as an inhibitor of cancer cell growth and metastasis via the retinoic acid receptor pathway....
JUN 21, 2018
Clinical & Molecular DX
JUN 21, 2018
Unique Gene Signature in the Blood Indicates TB Diagnosis
A unique series of genes could tell doctors that a person will develop a tuberculosis (TB) infection months before symptoms are visible. From The Francis C...
JUN 30, 2018
JUN 30, 2018
CD4 T Cells Responsible for Inflammatory Bowel Disease
A specific subset of immune cells could be targeted to better treat inflammatory bowel disease (IBD). A new University of Alabama at Birmingham study point...
AUG 01, 2018
Cell & Molecular Biology
AUG 01, 2018
Levels of One Molecule, LAC, can Diagnose Depression
Depression can be hard to classify and therefore, challenging to treat. New work could help change that....
AUG 16, 2018
Clinical & Molecular DX
AUG 16, 2018
Nanotech patch makes light-up medical tests 100x brighter
Researchers have developed a high-tech fix that uses metal nanostructures to increase the fluorescence intensity by 100 times in diagnostic tests. It&rsquo...
SEP 15, 2018
Genetics & Genomics
SEP 15, 2018
Data-based Health Management Tool for Aortic Aneurysm
This tool might be extrapolated for many other disorders, and may free patients from repeated doctor visits....
Loading Comments...