Seven more babies have been born in the United States with Zika-related birth defects, raising the total to 54 and reflecting a steep rise, the Centers for Disease Control and Prevention (CDC) said yesterday in an update.

In research news, Brazilian researchers report microcephaly in 70% of babies born with Zika-related problems, and a US group has mapped the entire genome of the Zika-transmitting Aedes aegypti mosquito.

In yesterday's update, the CDC also noted two more pregnancy losses involving Zika-related defects, lifting that total to seven.

According to the latest information from the CDC US Zika Pregnancy Registry, 1,617 pregnant women with Zika infections have been under monitoring, and 1,228 of them have completed their pregnancies.

Microcephaly often subtle

In the Brazilian study, the researchers detailed a spectrum of features they're observing during clinical exams and imaging of babies born with Zika birth defects. Their findings on 83 children born with Zika-related problems appeared Mar 22 in the American Journal of Medical Genetics.

They saw microcephaly in 70% of the babies, but it was often subtle. Other common findings included redundant scalp and abnormal cranial shape due to arrested brain growth.

Musculoskeletal problems included joint immobility, deep and multiple dimples, hand or finger contractures, feet malposition, and arthrogryposis involving multiple joints.

Neurologically, the team saw several alternations in motor activity, severe hypertonia (difficulty with mobility and flexing), and behaviors such as excessive and inconsolable crying. Brain imaging often showed calcifications, underdeveloped brain stem and cerebellum, and marked decreased in brain volume.

Aedes gene mapping

Using a new, cheaper, and faster method of assembling an organism's genetic sequence from scratch, teams from Texas and Massachusetts yesterday reported in Science that they assembled the Ae aegypti genome.

Called 3D genome assembly, the process determines how the genome folds to fit inside the cell nucleus, allowing teams to "stitch together" hundreds and millions of short DNA reads.

Researchers had attempted to sequence the Ae aegypti genome, but it was challenging, because the chromosomes are much longer than humans'. They used the assembly data in their computers to test the new process, the results of which they said might yield new information about battling Zika virus.

They also assembled the genome of the Culex quinquefasciatus, the main carrier of West Nile virus.

See also:

Mar 23 CDC updates on Zika birth defects and pregnant women with Zika virus

Mar 22 Am J Med Genet abstract

Mar 23 University of California–San Diego press release

Mar 23 Science abstract

Mar 23 Baylor College of Medicine press release