Infection with WNV can be without symptoms or can lead to West Nile fever or severe West Nile disease.1 It is usually transmitted by mosquito bites,2 and there is limited evidence of transmission through breastmilk.3 According to the CDC, there is no need to routinely screen people who breastfeed or to interrupt breastfeeding if they have been diagnosed with the West Nile virus.
Consult a physician when planning on donating breastmilk, especially if to a premature and sick infant. If concerned about the West Nile virus, donors can request a simple blood test from a healthcare provider.
Please see How can breastmilk be pasteurized at home? for more information on heat-treating and pathogens.
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