Revealed: Zika’s life-threatening birth defects you DIDN’T know about
The mosquito-borne Zika virus can lead to extensive birth defects that go beyond microcephaly, a Brazilian study suggests.
Researchers studied 11 babies diagnosed with Zika and found they had a range of neurological impairments including small skulls and brains.
Many also had an underdeveloped cerebellum, the part of the brain responsible for motor skills, and an absence of normal folds in the cerebral cortex, the gray matter that handles memory, language, social skills and problem solving.
Some Zika babies may not be born with microcephaly but still suffer life-long complications, such as two-month-old Micaela Milagros Mendoza (pictured), a Venezuelan child who has Zika-related calcification in her brain and scarring in her retinas
‘Microcephaly is not the only thing that happens with fetal Zika infection,’ said senior study author Dr Amilcar Tanuri, a researcher in the laboratory of molecular virology at the Federal University of Rio de Janeiro.
Instead, Zika should be considered a congenital viral disease like rubella or cytomegalovirus, Dr Tanuri said.
‘Some babies do not survive and the ones that survive carry several developmental or cognitive delays or deficits,’ Tanuri added.
Zika has been reported in at least 59 countries and territories since it first appeared in the Americas last year in Brazil, according to the World Health Organization.
There are more than 25,000 cases of the mosquito-borne virus in the United States and its territories, including more than 2,300 involving pregnant women.
Most of the cases are in Puerto Rico, but there is a limited active outbreak in Miami.
The virus has been linked to thousands of babies being born with microcephaly.
Ten of the 11 mothers included in the study in Paraiba, a state in northeastern Brazil, had symptoms of Zika infection during the first half of pregnancy, researchers reported October 3rd in JAMA Neurology.
The women all had confirmed Zika virus diagnoses during pregnancy and ultrasound exams that showed some fetal abnormality in brain development.
Cases were referred between October 2015 and February 2016.
The only known way to cut the Zika spread is to spray outbreak zones like Miami (pictured)
Zika virus was identified in amniotic fluid, placenta, cord blood and neonatal tissues collected postmortem because three of the 11 babies died within 48 hours of delivery and two mothers consented to autopsies.
These deaths resulted in a perinatal mortality rate of about 27 percent.
The remaining infants were followed from gestation to 6 months old.
Researchers tested for other causes of microcephaly, such as genetic disorders and infections, and results were negative. The Zika virus genome was found in the tissues of both the mothers and their babies.
One limitation of the study is that most imaging was done during pregnancy, and more images after delivery would be needed to better assess brain damage in the children, the authors note.
Even so, the findings suggest that microcephaly is a result of several brain injuries related to the Zika virus, the researchers conclude.
As a result, they propose describing cases as having ‘congenital Zika syndrome,’ rather than just microcephaly, which is only one sign of the syndrome.
Nerve cells in the brain migrate in fixed ways early in life to form different critical regions of the brain, such as the cortex and the cerebellum, said Dr. Raymond Roos, a researcher at the University of Chicago Medical Center and author of an accompanying editorial.
‘Zika virus infection of the fetus disturbs this migration, resulting in a number of developmental abnormalities of the brain, such as microcephaly,’ Roos said by email.
Even if infants don’t appear to have microcephaly, they may still suffer lasting effects from Zika, Roos noted.
‘Physicians should scrutinize babies who are born from mothers who have been infected with Zika virus during pregnancy in special ways, even if the babies have normal sized heads,’ Roos said.
‘These babies should be carefully evaluated with respect to the timing of their milestones and intellectual development.’
LATEST ON ZIKA: WHAT WE KNOW ABOUT THE VIRUS
HOW DO PEOPLE GET IT?
Zika is transmitted to people through the bite of infected female mosquitoes, primarily the Aedes aegypti mosquito.
It is the same type that spreads dengue, chikungunya and yellow fever.
The Pan American Health Organization (PAHO) said Aedes aegypti mosquitoes are found in all countries in the Americas except Canada and continental Chile.
Zika will likely reach all countries and territories of the region where Aedes mosquitoes are found.
The virus can also be transmitted through sex, from either a male or female partner who has been infected.
A few cases of apparent infection via blood transfusion have been reported.
A mother can pass the virus to her unborn fetus.
Current research indicates the greatest microcephaly risk is associated with infection during the first trimester of pregnancy, but health officials have warned an impact could be seen in later weeks.
Recent studies have shown evidence of Zika in amniotic fluid, placenta and fetal brain tissue.
HOW DO YOU TREAT ZIKA?
There is no treatment or vaccine for Zika infection.
Companies and scientists are racing to develop a safe and effective vaccine for Zika.
However, a preventative shot is not expected to be ready for widespread use for at least two or three years.
WHAT ARE THE DANGERS?
The CDC concluded that infection with the Zika virus in pregnant women is a cause of the birth defect microcephaly.
Microcephaly is a condition defined by unusually small heads that can result in developmental problems, and other severe brain abnormalities in babies.
The CDC said that since the causal relationship had been established, several important questions must still be answered with studies that could take years.
The World Health Organization in an updated assessment said the ‘most likely explanation’ is that Zika virus infection during pregnancy is a cause of congenital brain abnormalities including microcephaly.
Brazil recently reported 1,949 confirmed cases of microcephaly believed to be linked to Zika infections in pregnant women.
It is investigating more than 3,030 suspected cases of microcephaly.
The WHO also updated its guidelines to say the infection is a trigger of Guillain-Barre syndrome (GBS), a rare neurological disorder that can result in paralysis.
Its previous statement, based on a rapid assessment of evidence, said there was strong scientific consensus that Zika virus caused GBS, microcephaly and other neurological disorders.
WHAT ARE THE SYMPTOMS?
People infected with Zika may have a mild fever, skin rash, conjunctivitis, muscle and joint pain and fatigue that can last for two to seven days.
But as many as 80 per cent of people infected never develop symptoms.
HOW CAN ZIKA BE CONTAINED?
Efforts to control the spread of the virus focus on eliminating mosquito breeding sites and taking precautions against mosquito bites such as using insect repellent and mosquito nets.
U.S. and international health officials have advised pregnant women to avoid travel to Latin American and Caribbean countries, sections of Miami, Florida in the United States and Singapore where they may be exposed to Zika.
They are also advising that men and women who have traveled to Zika outbreak areas use condoms or abstain from sex for six months to prevent sexual transmission of the virus.
HOW WIDESPREAD IS THE OUTBREAK?
Active Zika outbreaks have been reported in at least 59 countries or territories, most of them in the Americas, according to the CDC. Brazil has been the country most affected.
Africa: 1 country
Americas: 49 countries
Anguilla, Antigua and Barbuda, Argentina, Aruba, The Bahamas, Barbados, Belize, Bolivia, Bonaire, Brazil, British Virgin Islands, Cayman Islands, Colombia, Costa Rica, Cuba, Curaçao, Dominica, Dominican Republic, Ecuador, El Salvador, French Guiana, Grenada, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Jamaica, Martinique, Mexico, Nicaragua, Panama, Paraguay, Peru, Saba, Puerto Rico, Saint Barthelmy, Saint Lucia, Saint Martin, Saint Vincent and the Grenadines, Saint Eustatius, St. Maarten, St. Kitts and Nevis, Suriname, Trinidad and Tobago, Turks and Caicos, United States, U.S. Virgin Islands, Venezuela.
Asia: 1 country
Oceania/Pacific Islands: 8 countries
American Samoa, Fiji, Kosrae, Federated States of Micronesia, Marshall Islands, New Caledonia, Papua New Guinea, Samoa, Tonga.
HISTORY OF ZIKA
The Zika virus is found in tropical locales with large mosquito populations.
Outbreaks of Zika have been recorded in Africa, the Americas, Southern Asia and the Western Pacific.
The virus was first identified in Uganda in 1947 in rhesus monkeys and was first identified in people in 1952 in Uganda and Tanzania, according to the WHO.
ANY OTHER ZIKA-RELATED COMPLICATIONS?
Zika has also been associated with other neurological disorders, including serious brain and spinal cord infections.
The long-term health consequences of Zika infection are unclear.
Other uncertainties surround the incubation period of the virus and how Zika interacts with other viruses that are transmitted by mosquitoes, such as dengue.