dr. denise jamieson is with the centers for disease control and prevention. dr. jamieson, thank you for joining us. >> you're most welcome. >> there are a lot of questions circulating about this and i think it comes down to two basic categories. what do we know about this disease and, more importantly, what don't we know? >> what we know is that zika is generally a very mild disease inned inned a adults. it causes and a rash and joint pain. we know that it causes microcephaly and other brain disorders. >> if you are in the pregnancy population, what should you be doing to protect yourself? >> the best way to protect yourself is if you can avoid travel or residing in areas where there's ongoing zika virus transmission. if you are in an area where that is occurring, you can take steps to protect yourself. notably, avoiding mosquito bites and also ensuring that your partner uses a condom. >> i know that here in the united states we have not had one case of transmission from mosquito bites at this point. in fact, the mosquitos that are responsible for transmission ar

dr. denise jamieson is with the c.d.c. zika virus response team. >> at the beginning of the outbreak, we were hoping that women without symptoms would not have adverse pregnancy outcomes, and since we now know that adverse pregnancy outcomes can occur in women without symptoms, we felt it was really important to start reporting these numbers. >> reporter: the c.d.c. is now monitoring 157 pregnant women with zika infection in the 50 states and another 122 in puerto rico and other u.s. territories. in the u.s., most cases were acquired from travel to affected areas, and a few through sexual contact. the c.d.c. says most of the women are still pregnant. it's too early to know how often the virus infects the fetus. >> we know of less than a dozen cases of pregnant women with zika who have had adverse outcomes, including miscarriage and birth defects. >> reporter: in february, we met one of those women, samantha mejia, at her home in illinois. she had recently miscarried after becoming infected with zika virus while vacationing