The question of the early diagnosis of asymptomatic and subpatent malaria in pregnancy: Implications for diagnostic tools in a malaria endemic area

G N Uyaiabasi; A Olaleye; C J Elikwu; R I Funwei; C Okangba; A Adepoju; A Akinyede; O O Adeyemi; O Walker

doi:10.1016/j.eurox.2023.100233

The question of the early diagnosis of asymptomatic and subpatent malaria in pregnancy: Implications for diagnostic tools in a malaria endemic area

Eur J Obstet Gynecol Reprod Biol X. 2023 Sep 2:19:100233. doi: 10.1016/j.eurox.2023.100233. eCollection 2023 Sep.

Authors

G N Uyaiabasi^{1

2

3}, A Olaleye^{2

4}, C J Elikwu^{2

5}, R I Funwei^{1

2}, C Okangba⁵, A Adepoju^{2

6}, A Akinyede³, O O Adeyemi³, O Walker^{1

2}

Affiliations

¹ Department of Pharmacology, Babcock University, Ilishan-Remo, Ogun State, Nigeria.
² Centre for Advanced Medical Research and Biotechnology, Babcock University, Ilishan-Remo, Ogun State, Nigeria.
³ Department of Pharmacology, Therapeutics & Toxicology, University of Lagos, Nigeria.
⁴ Two Hills Medical Clinic, Two Hills, Alberta, Canada.
⁵ Department of Medical Microbiology, Babcock University, Ilishan-Remo, Ogun State, Nigeria.
⁶ Centre for Research, Innovation & Development, Babcock University Teaching Hospital, Ilishan-Remo, Ogun State, Nigeria.

Abstract

Objectives: Malaria in pregnancy (MIP) is a major healthcare challenge in low-income countries with high malaria endemicity. Early but accurate diagnosis and appropriate treatment is the hallmark of preventing disease progression/adverse outcomes in the mother, foetus and neonates. We assessed the comparative diagnostic performance of Malaria Rapid Diagnostic Test (mRDT), microscopy and PCR for malaria diagnosis in pregnant women for early detection of asymptomatic malaria in pregnant women.

Study design: Five hundred and twenty Pregnant women attending study clinics within Ikene and Remo North LGAs with gestational age between 16 and 29 weeks, willing and consented; were enrolled into the study. Blood samples collected via venepuncture were screened for malaria using microscopy, mRDTs kits, and PCR techniques on their first visit (V₁) and at delivery. The parasite positivity rates, sensitivity and specificity were calculated and compared for each technique using PCR as the standard. Data was entered into REDCap® online database and analysis done using Stata and MedCalc®.

Results and conclusions: Average age of enrolled women was 28.8 years and mean gestational age was 21.0 weeks. The parasite positivity rates were 4.3%, 8.8% and 25.0% for microscopy, mRDT and PCR at V₁ and was 2.4%, 3.4% and 43.4% at delivery, respectively. Sensitivity for microscopy and mRDT was 11.2% and 30.3% respectively at V₁, while specificity was 98.2% and 98.5%. At delivery, the sensitivity reduced to 1.6% and 4.9%; while specificity was 96.9% and 97.6% respectively. Only 2.3% cases correlated with all three diagnostic methods. Our data showed a decrease in sensitivity of the diagnostic methods as pregnancy progressed, which may be due to very low parasitaemia, but high specificity. Our study demonstrated a high rate of subpatent parasitaemia amongst pregnant women. This finding therefore raises the question of the effect of subpatent parasitaemia on the health of the mother and foetus.

Keywords: Asymptomatic malaria; Malaria; Microscopy; PCR; Pregnancy; Subpatent parasitemia.