Zika virus also linked to limb joint deformities in babies

Aside from causing microcephaly, a birth defect in which the brain doesn’t develop fully resulting in a smaller head size, new research suggests that the Zika virus may also be linked to acongenital joint condition called arthrogryposis.

Researchers looked at medical records of seven Brazilian infants who were infected with Zika while still in the womb and were also diagnosed with arthrogryposis.

The newborns all showed symptoms of underlying neurological damage, most notably the forming of scar-like calcium deposits in the brain and shrunken brain volume, but no physical abnormalities within the joints themselves. Moreover, at least one case of the joint condition was seen in an infant without microcephaly.

The deformities left the children with clubfoot, hyperextended knees, and dislocated hips, among other injuries.

It is still too early to be completely sure that these deformities were caused by the Zika virus, but the researchers concluded that microcephaly is not likely to be the only health problem that comes with congenital Zika infection. Aside from microcephaly and arthrogryposis, several of the children appeared to have vision and hearing problems as well.

“This disease goes beyond microcephaly, with other symptoms such as visual and hearing impairment, and unusual signs and symptoms different from other congenital infections,” the authors wrote, adding that microcephaly and other Zika-caused impairments should be seen as part of a broader congenital Zika syndrome.

A child with arthrogryposis is born with joint contractures, which happen when otherwise flexible, stretchy muscles become permanently hardened and shortened. Though most commonly found in the limbs, it can also occur in the jaw and spine. In arthrogryposis, these contractures can leave children with fingers frozen in place and rigid limbs that make walking impossible, though cases vary in severity.

Seventy to 80% of cases are tied to other neurological conditions, but before Zika, no virus or bacteria known to infect developing fetuses was thought to cause arthrogryposis. None of the children in the study tested positive for these other cognitive infections, adding more support for Zika’s role.

But without further research, it’s impossible to know how Zika can cause arthrogryposis. Offering an educated guess, the researchers theorized that the virus might directly interfere with the development of motor neurons that send signals to the limbs or wreak havoc on the arteries and veins that provide nourishment to the muscles.

Because it may take years for other skeletal or muscular deformities to show up in Zika-infected children, they recommended that these children receive follow-up evaluations by an orthopedist, even if they were already examined at birth.

Tags: featured

Category: Features, Health alert