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Portable Device to Detect Zika Virus


An international team of researchers has developed a low-cost and portable product for detecting the Zika Virus. After using their device to test for the Zika virus in monkeys, the researchers are looking to product development as their next step.

The test is nucleic-acid based and has three steps: amplification, Zika detection, and CRISPR-Cas9-aided strain identification. Amplification is necessary because the viral load in samples such as saliva is significantly smaller than the viral load present in samples like urine.

Once the sample has been amplified, it goes into an RNA sensor called a toehold switch. The team’s research paper states that the switch can “be designed to bind and sense virtually any RNA sequence.” The RNA sensors are deployed via a paper disc that provides a sterile and abiotic environment for them. The paper changes color from yellow to purple if positive.

In the final step, the gene-editing mechanism, CRISPR-Cas9, searches the whole gene sequence for genetic markers. According to the Harvard Gazette, this step allows it to differentiate between strains of the Zika Virus.

This process improves upon previous tests which performed serum analyses that tested for the antibodies to certain viruses. In the past, this led to false positives, as the tests were unable to differentiate between the Zika Virus and close relatives like the dengue virus that share a geographical range.

Similarities between the targeted Zika Virus genomic sequences and those of the dengue virus range between 51 to 59 percent.

To ensure the accuracy of their test, Keith Pardee, a faculty member of the University of Toronto, told ResearchGate that the researchers exposed their test to low and high concentrations of the dengue virus, as well as “off-target regions of the Zika genome.” It differentiated between the target genome and everything else successfully.

All three components of the test can be freeze-dried for storage and distribution without damaging their effectiveness, which allows them to be sent to rural clinics for use. This means that even low-resource areas could have access to faster and more accurate tests for the Zika Virus. Previously, Pardee said, people needed to travel to urban areas for such accurate tests.

In an interview with ResearchGate, Pardee noted numerous potential benefits of the team’s test. It could potentially track the Zika Virus outbreak, and it would help physicians to more quickly identify and treat the infected. Physicians can also then take precautions to ensure the virus doesn’t spread.

– Anastazia Vanisko

Photo: National Cancer Institute

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WHO and PAHO Launch Worldwide Zika Virus Database

Zika Virus Database

The World Health Organization (WHO) has teamed up with the Pan American Health Organization (PAHO) to launch a Zika virus database to list and categorize all scientific studies on the Zika virus worldwide. The project is focused on helping global researchers understand and combat the virus.

The two agencies have identified and collected all investigations and research on Zika, including those that have been, or are in the process of being published and compiled them into a searchable database, according to a recent press release by the PAHO.

Experts creating the Zika virus database included the search mechanism in order to help researchers explore unknown factors about the possible relationship between Zika and congenital malformations.

The WHO declared a public emergency on Feb. 1, 2016, due to Zika’s suspected link to a range of serious health concerns, including birth defects in babies born to mothers who are infected with the virus and the development of neurological disorders in adults.

Researchers have been focused on identifying a correlation between Zika and microcephaly, a rare condition that causes infants to be born with abnormally small heads and brain damage.

Zika is a predominately mosquito-borne disease that arrived in Brazil last spring. Since then, it has spread to 34 countries and territories in the Americas. Between 3 to 4 million people could be infected with the virus by early next year, according to the WHO.

Communities affected by poverty face the most risk, as the virus is easily transmitted in crowded areas where access to sheltered air conditioned space is limited. A lack of running water and waste management combined with poor housing in urban areas also contributes to the continued spread of the virus.

The Zika virus database is part of the WHO’s wider plan to combat the disease globally through its Strategic Response Framework and Joint Operations Plan.

The strategy is currently focusing on mobilizing and coordinating partners, experts and resources to help countries provide medical care, communicate risks and proper protection measures to the affected communities. The initiative also involves fast-track research on vaccine development.

– Lauren Lewis

Photo: Flickr