Table 2.
Prospective cohort studies studying absolute risks of adverse outcomes following maternal ZIKV infection
| Location | Enrolment period | Enrolment 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, Brazil | September 2015–May 2016 | Symptoms of infection (rash) | 53% (182/345) | RT-PCR | N.A. | N.A. | 46% (58/125†) | 17 |
| Belem, Pará, Brazil | October 2015–December 2017 | Symptoms of infection | 44% (134/308) | RT-PCR, serological | N.A. | N.A. | 2% (2/101‡) | 23 |
| Manaus, Brazil | November 2015–December 2016 | Symptoms of infection | 42% (322/762) | RT-PCR | N.A. | N.A. | 17% (56/322) | 66 |
| Pernambuco, Brazil | December 2015–June 2017 | Symptoms of infection (rash) | 40% (277/694) | RT-PCR, serological | N.A. | N.A. | 24.3% (45/185¶) | 25 |
| French Guiana | January 2016– July 2016 |
Confirmed infection | 100% (300/300) | RT-PCR, serological | 26% (76/291) | RT-PCR or serological | 14% (42/291§) | 18 |
| São José do Rio Preto, São Paulo, Brazil | February 2016– October 2016 |
Symptoms of infection | 26% (54/216) | RT-PCR | 35% (18/51) | RT-PCR and serological | 28% (15/54) | 20 |
| French territories in the Americas | March 2016– November 2016 | Symptoms and confirmed infection | 100% (546/546) | RT-PCR | N.A. | N.A. | 7% (39/546) | 19 |
| Jundiaí, São Paulo, Brazil | March 2016–August 2017 | Attendance at high-risk pregnancy clinic | 8% (44/574) | RT-PCR | 5% (19/409) | RT-PCR | 23% (10/44) | 24 |
| La Virginia and Dosquebradas, Colombia | 2016 | Confirmed infection | 100% (86/86) | RT-PCR | N.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.