This is the first short news article written by students, during the professional development class of Spring 2024, about each other's research.

Student Spotlight: Shorooq Alharbi

By Alison Jennings

A female Aedes aegypti mosquito, needing protein for her eggs, slowly sucks out blood from an unsuspecting human. “Ugh. A mosquito.” The person swats at the bug, thinking she is a mere nuisance, but the damage is already done- the bite has not only caused swelling in the person’s arm, but it has also transferred a vexing virus. Within 10 days, the bitten victim might start to show symptoms of Dengue fever. Dengue fever is a global issue, with cases documented in Africa, the Americas, South-East Asia, as well as Western Pacific and Eastern Mediterranean regions. According to the World Health Organization, cases surged ten-fold (from 500,000 to 5.2 million) within the past two decades. New methods are needed to better understand virus transmission in light of these skyrocketing cases

“In the past, people have really only cared about whether female mosquitoes carry the virus, since the females are the ones that will transmit diseases to people. But in truth, male mosquitoes can be responsible for the virus being maintained in the mosquito population” says Shorooq Alharbi, a researcher in vector-borne diseases at Penn State

Alharbi is studying just how viruses are transmitted within mosquito populations. The virus can spread in two ways: either it is passed down from mother to egg (aka vertical transmission), or the virus is spread between male and female insects via mating (aka horizontal transmission).

“It’s been known that vertical transmission of certain viruses exists in mosquitoes since 1905. But the significance of this transmission as an important maintenance mechanism wasn’t appreciated until the late 1970s/early 1980s. Horizontal transmission of the virus is even less understood. In the Rasgon lab, we’re trying to gain a better understanding of how Dengue and other viruses spread within mosquito populations, by considering both vertical and horizontal transmission.”

Part of the reason that within-population transmissions of Dengue virus is poorly understood is that there are four known strains of the virus, and each strain has different genetic makeup. This means that the different strains could be transferred to people (or mosquitoes) at different rates. The first step in Alharbi’s research is to determine which version of the virus is most successful at vertical and horizontal transmission.

“Once we detect specific viral genotypes that effectively spread within mosquito populations, we can start looking into factors about the mosquitoes themselves that promote within-population transmission.” Alharbi hopes to build our understanding about vector-borne diseases and minimize the damage done to humans by insects.

Shorooq Alharbi is a PhD student in the Department of Entomology. She is advised by Dr. Jason Rasgon. This project is funded by the Saudi Arabian Cultural Mission (SACM).