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. 2018 Nov 12;12(11):e0006913.
doi: 10.1371/journal.pntd.0006913. eCollection 2018 Nov.

Estimation of HTLV-1 vertical transmission cases in Brazil per annum

Carolina Rosadas  1   2 , Bassit Malik  1 , Graham P Taylor  1 , Marzia Puccioni-Sohler  3   4
Affiliations

Estimation of HTLV-1 vertical transmission cases in Brazil per annum

Carolina Rosadas et al. PLoS Negl Trop Dis. .

Abstract

Background: Brazil has at least 800,000 HTLV-1 infected individuals. HTLV-1 can be transmitted via sexual intercourse, contact with blood and from mother to child, mainly by breastfeeding. Treatments for the high morbidity/mortality associated diseases (ATL and HAM/TSP) are limited, therefore, infection prevention is of utmost importance. However, antenatal screening is not routinely performed in Brazil. A lack of data regarding the number of individuals infected via breastfeeding impairs the development of government policies. The objective is to estimate the number of HTLV-1 infections occurring annually due to mother to child transmission (MTCT) in Brazil, nationally and regionally.

Methodology: To estimate HTLV-1 MTCT in Brazil the following variables are modelled: number of births, prevalence of HTLV-1 infection in pregnant women, breastfeeding duration rate and transmission risk according to breastfeeding period. The number of cases of HAM/TSP and ATL attributable to MTCT are also estimated.

Principal findings: In 2008, there were 2,934,828 live births in Brazil. HTLV prevalence in pregnant women in Brazil ranges between 0.1-1.05% by region. An estimated 16,548 HTLV-1 infected women are pregnant each year. According to the breastfeeding pattern and HTLV-1 prevalence of each region there are an estimated 3,024 new cases of HTLV-1 infection due to MTCT annually of which 2,610 are preventable through infant feeding advice. These 3,024 transmissions will result in 120-604 cases of ATL and 8-272 of HAM/TSP. North-East region comprises the high number of MTCT cases, followed by South-East.

Conclusions/significance: A high number of new HTLV-1 infections due to MTCT occur every year in Brazil. Antenatal screening and avoiding breastfeeding are essential to prevent subsequent development of HTLV-1-associated diseases.

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Conflict of interest statement

The authors have declared that no competing interests exist.

Figures

Fig 1
Fig 1. Estimation of HTLV-1 mother-to-child transmissions cases in Brazil.
A) Model used to calculate the number of breastfeeding women over time in Brazil: Breastfeeding duration (days) against HTLV-1 transmission; B-F) Model used to evaluate the HTLV-1 transmission risk according to breastfeeding duration rates in the different Brazilian regions: B) North; C) North East; D) Midwest; E) South East; F) South.
Fig 2
Fig 2. PRISMA flow chart for study selection.
The flow diagram indicates the numbers of studies reviewed in preparation of the current systematic review of HTLV prevalence in pregnant woman from Brazil. Adapted from [14].
Fig 3
Fig 3. Representative map of HTLV-1 prevalence in pregnant women in different Brazilians states.
The map was created with Paint 3D Windows and Adobe Photoshop CC 2018, using the open source map available at https://commons.wikimedia.org/wiki/Atlas_of_the_world.
See this image and copyright information in PMC

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