Table 2

Characteristics of included studies and assessment of the risk of bias*

StudyCountryNo of pairsStudy designPrimary methods for maternal HSV-2Use of antiretroviral therapyMaternal CD4 count closest to delivery (cells/mm3)Assessment of the risk of bias
Eligibili-ty criteriaMethods for maternal HSV-2Methods for infant HIV statusMethods for confound-dingAnaly-sisAttri-tionOverall risk of bias
Aebi-Popp et al16Ukraine1513Retrospective cohortSerologyHSV-2+
ZDV±NVP n=443, cART n=542
HSV-2−
ZDV±NVP n=283, cART n=183
Median 430 (IQR 290–580)LowMod.LowLowMod.Mod.Mod.
Bollen et al17Thailand307Retrospective cohortSerologyZDV n=151<200: n=33
200–499: n=166
≥500: n=107
LowLowLowLowMod.Mod.Low
Chen et al19USA402Retrospective cohortCultureZDV n=266<500: n=142
≥500: n=231
LowMod.LowLowMod.Mod.Mod.
Chen et al13USA78Case–controlSerologyZDV n=22 transmitters and n=29 non-transmitters
cART n=4 transmitters and n=22 non-transmitters
Median:
362 (cases)
448 (controls)
LowLowLowHighLowLowMod.
Cowan et al14Zimbab-we1448Case–controlSerologyNone≤200: n=217
201–400: n=447
≥401: n=679
Missing: n=184
LowLowLowMod.LowLowLow
Drake et al15Kenya175Case–controlSerologyAny ARVs n=25 transmitters and n=106 non-transmittersMedian at 32 weeks GA:
419
(IQR 299–620)
Mod.LowLowHighMod.LowMod.
Hitti et al21USA48Prospective cohortCultureNot reportedOf 58 women:
<200: n=4
200–500: n=23
>500: n=31
Mod.LowHighHighMod.Mod.High
Jamieson et al18Côte d’Ivoire250Prospective cohortSerologyZDV n=126<350: n=56
350–499: n=51
≥500: n=138
LowMod.LowHighMod.Mod.Mod.
Pitt et al22USA497Prospective cohortMethods not statedZDV n=167Mean ± SD:
399±254 (transmitters)
and 505±417 (non- transmitters)
Mod.HighLowHighMod.Low.High.
Van Dyke et al23USA204Prospec-tive cohortClinical diagnosisZDV n=174Median (IQR):
372 (277–579; transmitters)
and 453 (252–642; non-transmitters)
LowHighLowHighMod.Mod.High.
  • ARVs, antiretrovirals; cART, combination antiretroviral therapy; GA, gestational age; HSV-2, herpes simplex virus-2; LTFU, lost to follow up; mod., moderate; NVP, nevirapine; ZDV, zidovudine.