Screening of pregnant women for HTLV-1 could prevent infection of a thousand babies a year

A study estimated, through the development of a mathematical model, that the implementation of public policies to prevent the transmission of HTLV-1 through breastfeeding in Brazil would prevent the infection of more than a thousand children per year. The research was conducted by scientists at Imperial College London, in collaboration with research groups in Brazil, including Fiocruz Bahia, and published in the Lancet Global Health. Brazil's Ministry of Health recommends the suspension of breastfeeding for mothers with HTLV-1, however, testing is not offered by the Unified Health System (SUS, the Brazilian public health system) for pregnant women across the country.

This intervention reduces the risk of transmission of the virus to the child, preventing about 85% of infections. Only in some states, such as Bahia, testing is part of prenatal care, as a prevention policy. The implementation of testing for pregnant women is being assessed by the National Committee for Health Technology Incorporation (Conitec).

The human T-lymphotropic virus type 1 (HTLV-1) is a retrovirus of the same family as HIV, and can cause serious diseases such as cancer and chronic neurological disorders. This virus has transmission routes similar to HIV, and can contaminate a person through unprotected sex (sex without a condom), through sharp objects, or through breastfeeding. Currently, it is estimated that between 800 thousand and 2.5 million Brazilians are carriers of the virus.

The researchers assessed that, if massive testing of pregnant women for HTLV-1 were implemented, between 41 and 207 children per year would no longer develop adult T-cell leukemia, a type of cancer generated by HTLV-1, which is highly aggressive and usually fatal. Moreover, approximately 31 to 93 cases of HTLV-1-associated myelopathy – a progressive disease that affects the spinal cord – would also be prevented. This type of intervention can lead to future economic benefits for the Brazilian health system.

The mathematical model developed by the researchers is freely and openly available. The intention is that the work can be used by other countries to assess the cost-effectiveness of implementing public policies to prevent transmission through breastfeeding. The scientists point out that, as there is no treatment or vaccine for HTLV-1, the best policy to be adopted to combat the virus is to prevent new infections.