Reviewer 2's Review (Edith Lederman):

“The authors describe the interim results from a cohort study of healthy infants born in the Gambia with evidence of congenital CMV infection (case definition: positive urine PCR). They found that these infants did well clinically, at least during the early follow up period and that placental malaria was associated with congenital CMV. I think this manuscript contains useful information and is consistent with similar studies from other countries, but the manuscript requires revisions before it can be published.

The authors conclude that “more health complaints” are reported for CMV+ children and although they delineate the complaints nicely in Table 4, I can’t figure out what type of complaints account for their p value of 0.04 when all subcategories listed have p values greater than 0.2. From a clinical standpoint it would be important to know what the common complaints/reason for health care utilization are in the first year of life, if it is indeed increased from baseline. The authors refer to another study where malaise was a common complaint; did the authors assess for general malaise in their cohort?

The findings of first born and crowded conditions described/expanded upon in the abstract are not included in the discussion. Furthermore, is “first born” really a surrogate for maternal age and are younger mothers more likely to develop primary infections during pregnancy (and thus promote vertical transmission)? If you have the maternal ages it would be worthwhile excluding maternal age as a confounder.

I agree that exclusion of the infants born to mothers with severe infections during pregnancy and infants born prematurely will decrease the prevalence of congenital CMV. Prevalence will also be decreased by not checking the serologic status of infants – and missing those who were infected earlier in pregnancy and who are no longer shedding virus.

Do the authors really contend that mothers were all reinfected with CMV (last third of paragraph two in the Discussion) – or that CMV reactivation (and shedding) during pregnancy may also play an important role?

Could the authors comment on why hepatomegaly seems more common? Do they think this is CMV hepatitis or a manifestation of placental and/or recurrent malaria? Were LFTs available to comment on?”

N.B. These are the general comments made by the reviewer when reviewing this paper in light of which the manuscript was revised. Specific points addressed during revision of the paper are not shown.