Number infected in Midwest outbreak may be higher than first reported.

2003 DEC 10 - (NewsRx.com & NewsRx.net) -- Researchers at Oregon Health & Science University are trying to gain a better understanding of last summer's monkeypox outbreak. The researchers traveled to the Midwest twice during the past few months to obtain blood samples from residents exposed to the disease and a third trip was planned for December.

The samples will be used to better understand the human immune system's ability to fight monkeypox, information that will be critical for future vaccine development.

"The recent monkeypox outbreak in the Midwest provides a unique and important opportunity for medical research," explained Mark Slifka, PhD, assistant scientist at the OHSU Vaccine and Gene Therapy Institute (VGTI) and an assistant scientist at the Oregon National Primate Research Center. Slifka is also an assistant professor of molecular microbiology and immunology in the OHSU School of Medicine.

"Blood samples provided by those infected with monkeypox and those who were exposed but remained illness-free can give us insight into how the human body fights off poxviruses, including the number one killer - smallpox. Tracking immune responses as they occur is tremendously helpful not only in learning how to develop better vaccines, but in providing us an opportunity to observe firsthand how the immune system attacks and destroys an invading pathogen. Watching how these interactions unfold over time helps us to expand our basic understanding of this complex disease."

In addition to a better understanding of monkeypox infections, researchers at the VGTI hope to learn whether one of their theories is true: More people were infected with monkeypox during this past year's outbreak than initially reported.

"At the time of the outbreak, fairly strict criteria were used to determine which cases were 'suspect' and which ones could be confirmed as monkeypox infections," Slifka said. "However, we believe there's a strong chance that some people who were immunized against smallpox back in their childhood may have still maintained cross-reactive resistance to monkeypox infection as well.

"If this occurred, then monkeypox infection would have resulted in very limited disease symptoms or even no symptoms at all. If the symptoms were very mild, then no 'pox' lesions would develop on the skin and those people may have thought they were simply suffering from the common cold or may not have even noticed that they were sick. Therefore, it is possible that some cases of monkeypox went undiscovered or were under-reported."