Hantavirus maternal infection

There are 20 to 30 different types of Hantavirus and about a dozen have been associated with human infection ^{(Hjelle 2000, Uptodate 2018)}:

• Andes virus (ANDV), Bayou virus (BAYV), Black Creek Channel virus (BCCV),
• Choclo virus (CHOV), Dobrava / Belgrade virus (DOVB), Hantaan virus (HTNV),
• Laguna Negra virus (LANV), New York virus (NYV), Puumala virus (PUUV),
• Rio Mamore virus (RIOMV), Seoul virus (SEOV) and Sin Nombre virus (SNV).

Disease is transmitted through the inhalation of aerosolized particles of urine, feces, saliva or the remains of infected wild rodents; the virus lodges in regional lymph nodes and spreads to distant organs (Hjelle2000), causing two serious clinical forms of the disease ^{(Hjelle 2000, Uptodate 2018)}:

1. Haemorrhagic fever with Hantavirus renal syndrome (HFRS).
2. Hantavirus cardiopulmonary syndrome.

Hantavirus Renal Syndrome has been described in Europe and Asia and the Hantavirus Cardiopulmonary Syndrome in America, for that reason they are sometimes described as “Old world” and “New world” syndrome respectively.

Transmission from person to person is rare and has only been reported with one type of Hantavirus species, the ANDV ^(Padula1998), which has been detected in secretory cells of human salivary glands. Unlike other species, this Hantavirus has a high resistance to the antiviral properties of human saliva which would allow transmission from person to person specially through sexual contact and kisses. ^{(Hardestam 2009)}

According to PAHO, there is not sufficient evidence of interhuman transmission in North America to justify the practice of respiratory isolation methods with infected persons. The use of a surgical mask is recommended when faced with the possibility of interhuman transmission due to Andes species or other little known or unknown New World Hantavirus species. ^(OPS1999)

The most sensible recomendation regarding Hantavirus prevention is to minimize or eliminate contact with rodents at home or the workplace ^{(CDC 2019)}.

A healthy infant had IgG antibodies against SNV at 15 months of age. His mother had breastfed him and had died 8 months before due to an unconfirmed pulmonary Hantavirus syndrome and had breastfeed him. Although the authors ^(Pini1998) suggested the possibility that breast milk could be a source of transmission, no samples of milk or blood were taken from the mother and the infant had not become ill.

SNV viral RNA has been found in the milk of an infected mother who died in a few days; her three-week-old breastfed infant, breastfed until a few hours before the mother's hospitalization, neither became ill nor presented viral RNA in her analyzes. There were also antibodies against SNV in breast milk. ^(Pai1999)

Three newborns of mothers who suffered a HFRS in the 2nd trimester of pregnancy, were breastfed without problems ^{(JI 2017)}.

A 36-day-old infant died of ANDV. His mother, with severe ANDV infection since 6 days postpartum, breastfed him for the first 15 days, until the mother's hospitalization. PCR for ANDV was positive in breast milk, but both mother and paternal grandfather had ANDV infection, the only Hantavirus known to be transmitted by close contact. ^{(Ferrés 2020)}

An infant had an ANDV infection from 15 days of life, from which he recovered. His nursing mother had died 8 days postpartum from febrile respiratory failure without confirmation of Hantavirus infection. ^{(Bellomo 2020)}

All these cases suggest but do not confirm Hantavirus transmission through breast milk.

When breastfeeding, it is advisable to wash hands and cover mouth and nose with a mask especially when suspected of infection by Andes viruses or viral species from South America or of little experience in practice.