Method Validation Study for SARS-CoV-2 Viral RNA Detection in Cervical, Rectal, Amniotic Fluid, Placental, Umbilical Cord Blood, and Breastmilk Specimens in a Cohort of Unvaccinated Women in Manila, Philippines

Authors

  • Erlidia F. Llamas-Clark, MD, MPH, PhD Department of Obstetrics and Gynecology, College of Medicine and Philippine General Hospital, University of the Philippines Manila, Manila, Philippines; Institute of Child Health and Human Development, National Institutes of Health, University of the Philippines Manila, Manila, Philippines https://orcid.org/0000-0002-6296-8610
  • Mayan U. Lumandas, MD, MSc Research Institute for Tropical Medicine, Muntinlupa City, Philippines
  • Daniel C. Villarico, RMT Research Institute for Tropical Medicine, Muntinlupa City, Philippines
  • Amalea Dulcene D. Nicolasora, MSc Institute for Tropical Medicine, Muntinlupa City, Philippines https://orcid.org/0000-0003-3323-6303
  • Maria Stephanie Fay S. Cagayan, MD, PhD Department of Obstetrics and Gynecology, College of Medicine and Philippine General Hospital, University of the Philippines Manila, Manila, Philippines; Department of Pharmacology and Toxicology, College of Medicine, University of the Philippines Manila, Manila, Philippines https://orcid.org/0000-0003-2429-0551
  • Emmanuel S. Baja, MSc, ScD Institute of Clinical Epidemiology, National Institutes of Health, University of the Philippines Manila, Manila, Philippines; Department of Clinical Epidemiology, College of Medicine, University of the Philippines Manila, Manila, Philippines https://orcid.org/0000-0002-3888-8880
  • Maria Esterlita T. Villanueva-Uy, MD, MPH Institute of Child Health and Human Development, National Institutes of Health, University of the Philippines Manila, Manila, Philippines; Department of Pediatrics, College of Medicine and Philippine General Hospital, University of the Philippines Manila, Manila, Philippines https://orcid.org/0000-0002-9155-6893
  • Paulyn Jean B. Rosell-Ubial, MD, MPH College of Public Health, University of the Philippines Manila, Manila, Philippines https://orcid.org/0000-0002-8981-9551
  • Francisco M. Heralde III, MSc, MBA, PhD Department of Biochemistry and Molecular Biology, College of Medicine, University of the Philippines Manila, Manila, Philippine https://orcid.org/0000-0002-7794-2894

DOI:

https://doi.org/10.47895/amp.vi0.7618

Keywords:

Philippines, SARS-CoV-2, PCR, pregnant women, umbilical cord, placenta, amniotic fluid, breastmilk

Abstract

Objectives. To validate a method in detecting SARS-CoV-2 via RT-qPCR in pregnant and non-pregnant samples other than nasopharyngeal swabs and/or oropharyngeal swabs such as cervical, rectal, amniotic fluid, placental, umbilical cord blood, and breastmilk.

Methods. We performed a validation experiment using MGI easy extraction kits and BGI PCR kits on non-conventional specimens, including cervical, rectal, amniotic fluid, placental, umbilical cord blood, and breastmilk to detect and confirm the presence of SARS-CoV-2. In addition, we tested the validated method on 572 purposively sampled field-collected non-conventional specimens from a cohort of 109 unvaccinated pregnant and 47 unvaccinated non-pregnant women to assess which candidate non-conventional maternal- and fetal-associated specimens may contribute to maternal-fetal viral vertical transmission.

Results. Positive detection of SARS-CoV-2 viral RNA in non-conventional specimens was demonstrated and verified. Of the 572 non-conventional samples tested, 1.8% (10/572) were positively validated by RT-qPCR for SARS-CoV-2 in the maternal-associated specimens particularly the rectal (5), placental (1), and cervical (4) swabs among six pregnant and four non-pregnant individuals. In contrast, no SARS-CoV-2 viral RNA was detected in fetal-associated specimens.

Conclusion. The results of the validation study may serve as an additional diagnostic screening layer to support maternal-child care. Furthermore, viral detection in these non-conventional maternal specimens may also be utilized to provide guidance in the clinical management of neonates, and pregnant women during delivery.

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Published

2024-08-30

Issue

Vol. 58 No. 15 (2024)

Section

Articles

How to Cite

1.
Method Validation Study for SARS-CoV-2 Viral RNA Detection in Cervical, Rectal, Amniotic Fluid, Placental, Umbilical Cord Blood, and Breastmilk Specimens in a Cohort of Unvaccinated Women in Manila, Philippines. Acta Med Philipp [Internet]. 2024 Aug. 30 [cited 2025 Apr. 3];58(15). Available from: https://actamedicaphilippina.upm.edu.ph/index.php/acta/article/view/7618

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