Herpes Simplex Virus (HSV)

Herpes simplex virus (HSV) is a lifelong virus that is categorized into two distinct herpesvirus species, herpes simplex virus 1 (HSV-1) and herpes simplex virus 2 (HSV-2). HSV-1 is typically transmitted by oral-oral contact to cause oral herpes but can also cause genital herpes through oral-genital contact.  HSV-2 is typically sexually transmitted and causes genital herpes but can also cause infections in the mouth. Importantly, both types of virus can cause herpes disease in newborns and infants and can appear anywhere on the body.

In newborn infants, HSV infections are often severe and result in high rates of mortality and morbidity.  Every precaution needs to be taken to prevent infants from being exposed to the herpes virus and appropriate hand hygiene should be done before holding the infant.

Is it safe for a mother to breastfeed if she has active herpetic lesions?

Maybe. Women with herpetic lesions may transmit HSV to their infants by direct or indirect contact with the lesions. Breastfeeding is acceptable if no lesions are present on the breasts and if active lesions elsewhere on the mother are carefully and fully covered. In cases where a mother has herpetic lesions on her breast, the mother should temporarily refrain from breastfeeding her infant from the affected breast or feeding her infant expressed breast milk from the affected breast. She should discard expressed breast milk from the affected side until the lesions have healed. A mother may breastfeed her infant or express milk from the unaffected breast but should ensure that the lesions on the affected breast are completely covered to avoid transmission. Mothers should also follow appropriate hand hygiene practices to avoid transmission of herpes to her infant.

Some mothers may need additional support to maintain their milk production and/or supplement with their expressed human milk (previously expressed milk or expressed milk from the unaffected breast) or formula while herpetic lesions on the breast are healing. Mothers should talk with their physicians to determine if their lesions have healed and they can resume breastfeeding or expressing milk from the affected breast.

Is it safe for a mother to give her infant hand expressed or pumped breast milk if she has active herpetic lesions on her breast?

No. Breast milk can be contaminated if it comes in contact with active herpetic lesions through touching the breast during hand expression or via the pump. Therefore, if a mother has herpetic lesions on her breast, she should discard expressed breast milk from the affected side until the lesions have healed. Expressing breast milk will be important for maintaining milk production while not directly breastfeeding from the affected breast. Mothers should be vigilant about practicing appropriate hand hygiene and cleaning the pump parts thoroughly. Mothers should talk with their healthcare provider to determine if their lesions have healed and they can resume breastfeeding or expressing milk from the affected breast.

It is safe to use expressed breast milk from the unaffected breast, as long as the mother ensures that the lesions on the affected breast are completely covered to avoid transmission. Appropriate hand hygiene and cleaning the pump parts thoroughly are still important.

For more information about managing breastfeeding with specific medical conditions, read Lawrence RA, Lawrence R. (2016) Breastfeeding: A guide for the medical profession, 8th Edition.