GRADE SUMMARY OF FINDINGS TABLES

ANNEX 2GRADE SUMMARY OF FINDINGS TABLES

A. Are children breastfeeding from a mother diagnosed with Zika virus positively diagnosed with Zika virus infection?

B. Is Zika virus detected in breast-milk samples from women with suspected, probable or confirmed Zika virus (Zika virus) infection?

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World Health Organization, Geneva

NLM Citation

Guideline: infant feeding in areas of Zika virus transmission [Internet]. 2nd edition. Geneva: World Health Organization; 2021. ANNEX 2, GRADE SUMMARY OF FINDINGS TABLES.

AAre children breastfeeding from a mother diagnosed with Zika virus positively diagnosed with Zika virus infection?

Patient or population: Breastfeeding children from women with suspected, probable or confirmed Zika virus infection

Setting: Areas of Zika virus transmission

Intervention: Children breastfeed from a woman with Zika virus infection

Comparison: Not breastfeeding children

Outcomes

Number of participants (studies)

Certainty of the evidence (GRADE)

Comments

Confirmed Zika virus infection among children breastfeeding from a woman with suspected, probable or confirmed Zika virus infection

7 (3 observational studies)

⊕⊝⊝⊝

VERY LOW^a

Three studies provided evidence. One report was not considered due to ambiguous results. The cases reported by two reports were not breastfeeding and therefore were not included in this outcome. The child reported by one report was never breastfed, and the case reported by another was exposed in utero to Zika virus and was born with congenital Zika syndrome, and these two studies were therefore excluded from this analysis.

Confirmed Zika virus infection among children breastfeeding from a woman with suspected, probable or confirmed Zika virus infection: cohort study

6 (1 observational study)

⊕⊝⊝⊝

VERY LOW^b

One report refers to a cohort study including women with confirmed Zika virus infection. Only an abstract was identified by the search and it reported on six women with Zika virus detected in breast-milk by RT-PCR.

: Explanations

a: Downgraded for risk of bias, imprecision and publication bias.

b: Downgraded for risk of bias, imprecision and publication bias.

BIs Zika virus detected in breast-milk samples from women with suspected, probable or confirmed Zika virus (Zika virus) infection?

Patient or population: women with suspected, probable or confirmed Zika virus infection

Setting: areas of Zika virus transmission

Intervention: children breastfeed from a woman with Zika virus infection

Comparison: not breastfeeding children

Outcomes

Number of participants (studies)

Certainty of the evidence (GRADE)

Comments

Presence of Zika virus in breast-milk from women with suspected, probable or confirmed Zika virus infection by RT-PCR

10 (6 observational studies)

⊕⊝⊝⊝

VERY LOW^a

One study reported two mother and child pairs, while three studies reported one mother and child pair each. One study reported four mother and child pairs, only one of the mother’s breast-milk tested positive for Zika virus infection. There was a one mother and child pair, in which exposure occurred at the 9th gestational week and the breast-milk sample was positive for Zika virus at the 36th gestational week.

Presence of Zika virus in breast-milk from women with suspected, probable or confirmed Zika virus infection by RT-PCR: cohort study

27 (1 observational study)

⊕⊝⊝⊝

VERY LOW^b

There was a cohort study including women with confirmed Zika virus infection. Only an abstract was identified by the search, and it reported on 6 women with Zika virus detected in breast-milk by RT-PCR.

Presence of Zika virus in breast-milk from women with suspected, probable or confirmed Zika virus infection detected by cell culture

5 (5 observational studies)

⊕⊝⊝⊝

VERY LOW^a

One study reported two mother-and-child pairs, Three studies reported one mother-and-child pair each. Cavalcanti 2017 reported four mother-and-child pairs; only one of the mother’s breast-milk tested positive for Zika virus infection and was subsequently tested by cell culture.

: Explanations

a: Downgraded for risk of bias, imprecision and publication bias.

b: Downgraded for risk of bias, imprecision and publication bias.