Preventing Zika virus infection during pregnancy by timing conception seasonally

Abstract

It has come to light that Zika virus (ZIKV) infection during pregnancy can result in transplacental transmission to the fetus along with fetal death, congenital microcephaly and/or Central Nervous System (CNS) malformations. There are projected to be > 9, 200, 000 births annually in countries with ongoing ZIKV transmission. In response to the ZIKV threat, options to the full extent of the law" [14]. The CDC has issued recommendations for 54 ZIKV-exposed individuals to delay trying to get pregnant. Exposed women and exposed 55 asymptomatic men are recommended to wait 8 weeks, and men with symptoms are 56 recommended to wait 6 months [15]. No official stance on delaying pregnancy has been 57 taken for unexposed women. Problematically, the public is receiving a mixed message, susceptibily to infection, host/vector infectiousness, virus viability, the 86 transmssion-relevant contact rate among hosts/vectors, the density of hosts, and vector 87 abundance [16,21,27]. 88Aedes aegypti has seasonal variation in its ability to facilitate flavivirus transmission 89 because its abundance and competence as a vector are affected by temperature and 90 rainfall [28,29]. Using data from Puerto Rico-one of the U.S. locations with ongoing cohorts. This is because births are seasonal across human populations, and there is a 100 distinct birth pulse in most countries/regions that varies geographically in its seasonal 101 timing [31,32]. Fig 1b shows the birth seasonality in Puerto Rico, with the birth peak 102 from August-October. Due to birth seasonality, the percent of pregnancies experiencing 103 a specific trimester is not evenly distributed throughout the year (Fig 1d). For any 104 given country, the timing of the seasonal birth pulse, relative to the ZIKV transmission 105 season, will therefore determine the fraction of pregnancies at risk for maternal infection 106 and congenital ZIKV. For example, if a country has a birth pulse where sensitive 107 gestational periods coincide with the ZIKV season, more pregnancies in that country 108 will be at risk than elsewhere. Fortunately, if access to contraceptives and family 109 planning practices are proactively targeted for intervention, then the birth pulse could 110 be intentionally shifted and amplified regionally to minimize the risk of intrauterine 111 ZIKV infection for entire birth cohorts.