A study by Brazilian scientists of children born with multiple fixations of their joints – a condition known as anthrogryposis – suggests it may be linked to the Zika virus
Earlier this year, the US Centers for Disease Control and Prevention concluded that there is a causal relation between prenatal Zika virus infection and microcephaly – a condition where a baby’s head is much smaller than expected – and other serious brain anomalies. Microcephaly is an important clinical sign; however, it is not present in all cases of congenital Zika virus infection.
The latest study, published in the British Medical Journal, suggests that the Zika virus may cause other congenital conditions, some of which may not manifest themselves until later in life.
The website of the US Centers for Disease Control and Prevention (CDC) says,
Other problems have been detected among fetuses and infants infected with Zika virus before birth, such as defects of the eye, hearing deficits, and impaired growth. There have also been increased reports of Guillain-Barré Syndrome, an uncommon sickness of the nervous system, in areas affected by Zika.
The Brazilian study involved seven children born between October and November 2015; all had anthropryposis associated with congenital infections. Other common infectious causes of microcephaly were eliminated. The children then underwent extensive neurological and orthopaedic examinations along with several other investigations.
The Brazilian study says that arthrogryposis may be a sign of several as yet unspecified disorders rather than a specific disease. It is already associated with more than 300 disorders. The study says, ‘In our case series, the arthrogryposis did not result from abnormalities of the joints themselves but was likely to be of neurogenic origin, with chronic involvement of central and peripheral motor neurones, leading to fixed postures in utero and consequently deformities.’
The study concludes that more research is needed but recommends that, ‘As we do not know the potential implications of congenital Zika virus infection as it evolves, children must receive orthopaedic follow-up, even those with a standard first orthopaedic evaluation, because they could develop musculoskeletal deformities secondary to neurological impairment, central or peripheral, or both, as these occur in patients with cerebral palsy and other chronic encephalopathies.’
The Zika virus was first discovered in Uganda in 1947 and is transmitted through the bite of infected Aedes aegypti mosquitoes, which are mainly found in tropical and sub-tropical climates. It can be transmitted from an infected woman to her baby during pregnancy or around the time of birth. The current outbreak has seen cases in over 50 countries, most in South America and the Caribbean. As of 10 August there were six reported locally acquired, mosquito-borne cases in the USA, all of them in Florida.