Measures for the Prevention of Mother-to-Child Human T-Cell Leukemia Virus Type 1 Transmission in Japan: The Burdens of HTLV-1-Infected Mothers

Abstract

The main mode of mother-to-child transmission of the human T-cell leukemia virus (HTLV)-1 is through breastfeeding. Although the most reliable nutritional regimen to prevent HTLV-1 transmission is exclusive formula feeding, a recent meta-analysis revealed that short-term breastfeeding within 90 days does not increase the risk of infection. The protocol of the Japanese Health, Labor, and Welfare Science Research Group primarily recommended exclusive formula feeding for mothers who are positive for HTLV-1. However, there has been no quantitative research on the difficulties experienced by HTLV-1-positive mothers in carrying out these nutritional regimens, including the psychological burden. Therefore, this review was performed to clarify the burdens and difficulties encountered by mothers who are positive for HTLV-1; to this end, we analyzed the data registrants on the HTLV-1 career registration website "Carri-net" website. The data strongly suggest that it is not sufficient to simply recommend exclusive formula feeding or short-term breastfeeding as a means of preventing mother-to-child transmission; it is important for health care providers to understand that these nutritional regimens represent a major burden for pregnant women who are positive for HTLV-1 and to provide close support to ensure these women's health.

Keywords: exclusive formula feeding; human T-cell leukemia virus; mother-to-child transmission; short-term breastfeeding.

Figure 1

Health care providers who explained about mother-to-child transmission to HTLV-1-carrier mothers. The majority of health care providers who provided explanations regarding mother-to-child HTLV-1 transmission and prevention methods were obstetricians and gynecologists.

Figure 2

Nutrition protocol chosen by HTLV-1-infected mothers. Aggregated counts of all feeding period are shown in this figure.

Figure 3

Nutrition protocol chosen by HTLV-1-infected mothers. The data were separated into 2011 and before, 2011–2017, and 2017 according to the time of lactation. Nutritional methods selected varied depending on when they were implemented. The percentage of exclusive formula feeding increased from before March 2011 to after April 2017. On the other hand, the proportion of short-term breastfeeding was also increasing.

Figure 4

Preference of nutrition protocol assuming that short-term breastmilk feeding does not raise the possibility of HTLV-1 infection to the babies. About half of the HTLV-1-carrier mothers choose exclusive formula feeding even if short-term breastmilk feeding has no impact on the infection rate in infants for fear of infection risk.