Formalin Inactivation of Virus for Safe Downstream Processing of Routine Stool Parasite Examination during the COVID-19 Pandemic
Issued Date
2023-02-01
Resource Type
eISSN
20754418
Scopus ID
2-s2.0-85147874805
Journal Title
Diagnostics
Volume
13
Issue
3
Rights Holder(s)
SCOPUS
Bibliographic Citation
Diagnostics Vol.13 No.3 (2023)
Suggested Citation
Chinabut P., Sawangkla N., Wattano S., Thavorasak T., Bootsongkorn W., Tungtrongchitr A., Ruenchit P. Formalin Inactivation of Virus for Safe Downstream Processing of Routine Stool Parasite Examination during the COVID-19 Pandemic. Diagnostics Vol.13 No.3 (2023). doi:10.3390/diagnostics13030466 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/81668
Title
Formalin Inactivation of Virus for Safe Downstream Processing of Routine Stool Parasite Examination during the COVID-19 Pandemic
Author's Affiliation
Other Contributor(s)
Abstract
During the COVID-19 pandemic, the parasitology laboratories dealing with fecal samples for the diagnosis of gastrointestinal parasitic infections are confronting the unsaved virus-containing samples. To allow for safe downstream processing of the fecal samples, a protocol for preparing a fecal smear is urgently needed. Formalin was tested with or without isotonic forms for virus inactivation using porcine epidemic diarrhea virus (PEDV) as a representative, as it belongs to the Coronaviridae family. The results revealed complete inactivation activity of 10% formalin and 10% isotonic formalin on coronavirus after 5 min of treatment at room temperature. Both also inhibited Naegleria fowleri growth after 5 min of treatment at 37 °C without disruption of the structure. In addition to these key findings, it was also found that isotonic formalin could stabilize both red and white blood cells when used as a solution to prepare fecal smears comparable to the standard method, highlighting its value for use instead of 0.9% normal saline solution for the quantification of blood cells without active virus. The 10% isotonic formalin is useful to safely prepare a fecal smear for the diagnosis of parasites and other infections of the gastrointestinal tract during the COVID-19 pandemic.
