Table 2

Prospective cohort studies studying absolute risks of adverse outcomes following maternal ZIKV infection

LocationEnrolment periodEnrolment requirement% with laboratory confirmed maternal infection (n/N)Laboratory test for maternal infection% with laboratory confirmed congenital infection (n/N)Laboratory test for congenital infection% of absolute risk for adverse outcomes* among cases with confirmed maternal infection (n/N)Reference
Rio de Janeiro, BrazilSeptember 2015–May 2016Symptoms of infection (rash)53% (182/345)RT-PCRN.A.N.A.46% (58/125†)17
Belem, Pará, BrazilOctober 2015–December 2017Symptoms of infection44% (134/308)RT-PCR, serologicalN.A.N.A.2% (2/101‡)23
Manaus, BrazilNovember 2015–December 2016Symptoms of infection42% (322/762)RT-PCRN.A.N.A.17% (56/322)66
Pernambuco, BrazilDecember 2015–June 2017Symptoms of infection (rash)40% (277/694)RT-PCR, serologicalN.A.N.A.24.3% (45/185¶)25
French GuianaJanuary 2016–
July 2016
Confirmed infection100% (300/300)RT-PCR, serological26% (76/291)RT-PCR or serological14% (42/291§)18
São José do Rio Preto, São Paulo, BrazilFebruary 2016–
October 2016
Symptoms of infection26% (54/216)RT-PCR35% (18/51)RT-PCR and serological28% (15/54)20
French territories in the AmericasMarch 2016– November 2016Symptoms and confirmed infection100% (546/546)RT-PCRN.A.N.A.7% (39/546)19
Jundiaí, São Paulo, BrazilMarch 2016–August 2017Attendance at high-risk pregnancy clinic8% (44/574)RT-PCR5% (19/409)RT-PCR23% (10/44)24
La Virginia and Dosquebradas, Colombia2016Confirmed infection100% (86/86)RT-PCRN.A.N.A.23% (20/86)21
  • *The range of clinical features considered to be adverse outcomes varies between studies.

  • †n=125/182 ZIKV-positive pregnant individuals were followedand had known pregnancy outcomes.

  • ‡n=101/134 ZIKV-positive pregnant individuals were followedand had known pregnancy outcomes.

  • §n=291/300 ZIKV-positive pregnant individuals were followed and had known pregnancy outcomes.

  • ¶n=185/503 children who were able to be evaluated for at least one adverse outcome.

  • N.A., not available; RT-PCR, reverse transcription polymerase chain reaction; ZIKV, Zika virus.