By Ariana Eunjung Cha

Brazilian health authorities are sounding the alarm about a mosquito-borne virus that they believe may be the cause of thousands of infants being born with damaged brains.

The pathogen, known as Zika and first discovered in forest monkeys in Africa over 70 years ago, is the new West Nile -- a virus that causes mild symptoms in most but can lead to serious neurological complications or even death in others. Brazil's health ministry said on Nov. 28 that it had found the Zika virus in a baby with microcephaly — a rare condition in which infants are born with shrunken skulls — during an autopsy after the child died. The virus was also found in the amniotic fluid of two mothers whose babies had the condition.

"This is an unprecedented situation, unprecedented in world scientific research," the ministry said in a statement on its website

Brazil is investigating more than more than 2,400 suspected cases of microcephaly and 29 deaths of infants that occurred this year. Last year the country saw only 147 cases of microcephaly.

The situation in Brazil is so overwhelming that Angela Rocha, a pediatric infectious diseases specialist in Pernambuco, one of the hardest hit states, said in an interview that women may want to hold off on getting pregnant.

"These are newborns who will require special attention their entire lives. It's an emotional stress that just can't be imagined...," Rocha said. "We're talking about a generation of babies that's going to be affected."

Until a few years ago, human infections with the virus were almost unheard of. Then, for reasons scientists can't explain but think may have to do with the complicated effects of climate change, it began to pop up in far-flung parts of the world. In 2007, it infected nearly three-quarters of Yap Island's 11,000 residents. In 2013, Zika showed up in Tahiti and other parts of French Polynesia and was responsible for making an estimated 28,000 people so ill they sought medical care. It arrived in Brazil in May, where tens of thousands have fallen ill.

The World Health Organization, which has been monitoring the spread of the virus closely and issued an alert about the situation in Brazil, reported this month that it had popped up for the first time in the West African nation of Cape Verde and that it had led to additional illnesses in Panama and Honduras.

In the United States, the Centers for Disease Control and Prevention has found the virus in a few travelers returning from overseas, but says there have not come across any cases of people being infected by mosquitoes in the country.

Brazil has been struggling to contain the virus for months through both public education campaigns --which urge residents to use insect repelant and limit their time outdoors -- as well as by sending mosquito eradication teams house to house to treat places where aedes aegypti mosquito that carries the virus might breed. The health ministry said it was sending truckloads of larvicide -- enough to treat 3,560 Olympic-sized swimming pools -- to northeastern and southeastern states that have been most affected and that it would add 266,000 new community health agents to make the house calls.