Skip to main content

Table 3 Summary of studies reporting incidence of symptomatic influenza virus infection

From: Incidence of influenza virus infection among pregnant women: a systematic review

Study

Number of cases

Denominator

Crude incidence rate (CI)

95% CI

Pandemic or seasonal?

Study design

Grading system and scoreb

Hospital-based or clinic-based?

Duration of surveillance (months or years)

Country

Doyle 2013

194

295,941

6.6 per 10,000 pregnanciesa

(5.70–7.55)

Pandemic

Case series

NOS = 8

Both

13 months

US

Jamieson 2009

34

3,392,060

0.10 per 10,000 pregnancies

(0.07–0.14)

Pandemic

Case series

JBI = 6/7

Both

1 month

US

Madhi 2014

HIV uninfected:

38

1,023

371 per 10,000 pregnanciesa

(272–507)

Seasonal

Clinical trial

Low Risk (Cochrane)

Clinic

2 years (9 months total influenza season)

South Africa

HIV infected:

16

88

1,818 per 10,000 pregnanciesa

(1,167–2,832)

      

Total:

54

1,111

486 per 10,000 pregnanciesa

(375–630)

      
  1. aCalculated from provided number of cases or %
  2. b NOS Newcastle-Ottawa Scale, JBI JBI Critical Appraisal Checklist for Descriptive/Case Series, Cochrane The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials