New cases of Zika infection in pregnant women were down again for the 50 states over the 2-week reporting period ending Jan. 24, but U.S. territories saw a big increase, according to the Centers for Disease Control and Prevention.
It is important to note, however, that Puerto Rico, where most U.S. Zika cases are occurring, has been retroactively reporting cases for months, which can result in larger-than-normal increases.
The territories had 186 new cases of pregnant women with laboratory evidence of Zika virus infection for the 2 weeks ending Jan. 24, compared with 43 for the previous 2-week period. The corresponding numbers for the 50 states and the District of Columbia were 47 (Jan. 24) and 55 (Jan. 10), the CDC data show.
So far for 2016-2017, there have been 4,465 pregnant women reported to have Zika virus infection in the United States: 3,071 in the territories and 1,394 in the 50 states and D.C., according to the U.S. Zika Pregnancy Registry (states, territories, and the District of Columbia) and the U.S. Zika Active Pregnancy Surveillance System (Puerto Rico).
Of the nearly 1,400 state/D.C. Zika-infected pregnancies, 999 have been completed, with 38 infants born with birth defects and 5 defect-related pregnancy losses, the CDC said. There have been no Zika-related pregnancy losses reported in the states/D.C. since late June. The CDC is no longer reporting adverse pregnancy outcomes for the territories because Puerto Rico is not using the same inclusion criteria.
Among all Americans in 2015-2017, there have been 41,387 cases of Zika infection as of Feb. 1. Of that total, 35,334 cases, which is more than 85%, have occurred in Puerto Rico, according to data from the CDC’s Arboviral Disease Branch.
Zika-related birth defects reported by the CDC could include microcephaly, calcium deposits in the brain indicating possible brain damage, excess fluid in the brain cavities and surrounding the brain, absent or poorly formed brain structures, abnormal eye development, or other problems resulting from brain damage that affect nerves, muscles, and bones. The pregnancy losses encompass any miscarriage, stillbirth, and termination with evidence of birth defects.