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
- Author:
Erlidia F. Llamas-Clark
1
,
2
;
Mayan U. Lumandas
3
;
Daniel C. Villarico
3
;
Amalea Dulcene D. Nicolasora
3
;
Maria Stephanie Fay S. Cagayan
1
,
4
;
Emmanuel S. Baja
5
,
6
;
Maria Esterlita T. Villanueva-Uy
2
,
7
;
Paulyn Jean B. Rosell-Ubial
8
;
Francisco M. Heralde III
9
Author Information
- Publication Type:Journal Article
- Keywords: Breastmilk
- MeSH: Philippines; Sars-cov-2; Pregnant Women; Umbilical Cord; Amniotic Fluid; Polymerase Chain Reaction; Placenta
- From: Acta Medica Philippina 2024;58(15):32-38
- CountryPhilippines
- Language:English
-
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.
METHODSWe 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.
RESULTSPositive 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.
CONCLUSIONThe 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.
- Full text:20240915035523915195.pdf