Cytomegalovirus and Epstein-Barr virus in breast milk are associated with HIV-1 shedding but not with mastitis.

BACKGROUND

Breast milk HIV-1 load is associated with clinical and subclinical mastitis, and both milk viral load and mastitis are associated with increased mother-to-child-transmission of HIV-1 through breastfeeding. Bacterial infections may cause clinical mastitis, but whether other copathogens common in HIV-1 infection are associated with subclinical mastitis or HIV-1 shedding is unknown.

DESIGN

A cross-sectional study of HIV-1-infected breastfeeding women in Zimbabwe was performed to examine the relationship between a wide range of breast coinfections, mastitis, and HIV-1 shedding.

METHODS

Breast milk was cultured for bacteria and fungi and tested by PCR for mycobacteria, mycoplasmas, human herpesvirus (HHV)-6, HHV-7, HHV-8, cytomegalovirus, Epstein-Barr virus, and HIV-1 RNA and DNA. Symptoms of clinical mastitis were documented and subclinical mastitis was identified by breast milk sodium concentration (Na) and leukocyte counts.

RESULTS

Coinfections of milk were not associated with clinical or subclinical mastitis in the 217 women studied. Detection of HIV-1 RNA, but not DNA, in breast milk was associated with cytomegalovirus concentration (odds ratio = 1.8, P = 0.002) and detection of Epstein-Barr virus (odds ratio = 3.8, P = 0.0003) but not other coinfections in multivariate analysis.

CONCLUSION

Coinfection of breast milk with bacteria, fungi, or herpes viruses was not associated with mastitis. The associations between shedding of cytomegalovirus and Epstein-Barr virus with HIV-1 in milk suggest a local interaction between herpes virus infection and HIV-1 independent of mastitis. Cytomegalovirus and Epstein-Barr virus infections may impact HIV-1 shedding in breast milk and the risk of MTCT.