The World Health Organization is meeting in emergency session today to consider the international response to the Zika virus that has affected thousands of pregnant women and infants across Latin America. The virus, which is spread by mosquitoes, has been linked to a recent rise in serious birth defects in Brazil and other countries across the region, and WHO is warning it could soon reach the U.S. Finding a way to stop the explosive spread of this dangerous pathogen clearly needs to be a top priority for U.S. public health officials this year.
At this point, medical researchers have developed neither a vaccine to protect against infection by the virus nor a reliable test to detect its presence in the blood of women who are pregnant or may soon become pregnant. Nor has the link between the Zika virus and the recent spike in Brazil of cases of microcephaly — a congenital, irreversible condition characterized by brain damage from deformations in the skulls of newborn babies — been established with certainty. But as many as three to four million people in the hemisphere could be exposed to the virus over the next 12 months, prompting fears that the severity of the current outbreak could exceed that of last year's Ebola epidemic in West Africa.
In response, the Centers for Disease Control and Prevention has issued a travel advisory warning pregnant women against visiting the 20 or so countries where the virus is known to be present and to consult their doctors to determine whether they should be tested for it. That may slow the spread of the virus to the U.S., but it is unlikely to stop it completely. There are still too many unknowns regarding the exact mechanism through which the virus interacts with the body and its routes of transmission to predict when it can be brought under control.
The CDC's chief of infectious diseases, Dr. Anthony Fauci, says the United States' first line of defense should be stepped up mosquito control programs in subtropical regions of the nation, such as south Texas and southern Florida. He also said a new vaccine and test are in the works, but it's still too soon to know how effective they will be.
In the meantime the WHO is racing to catch up with a crisis that its director general, Dr. Margarett Chan, acknowledges her agency has been slow to respond to. The organization took a lot of heat last year from critics who charged it was behind the curve on the Ebola epidemic and that thousands of lives could have been saved had it acted earlier. Dr. Chan obviously doesn't want to repeat that experience, and at today's meeting she will be pushing her international colleagues hard to decide whether to declare a public health emergency.
That should be an easy call given that authorities in Brazil, where the epicenter of the outbreak is located, reported last week that the number of cases of microcephaly there had climbed to more than 4,100 since October, a 7 percent increase from the tally last week. That represents a huge jump for a virus that appears to have arrived in Brazil relatively recently. (Zika was first identified in Uganda in 1947, but researchers believe it only crossed the Atlantic within the last nine months.) Before the current outbreak, Brazil had recorded fewer than 200 cases of microcephaly a year.
The virus has taken it biggest toll so far in the marginalized, underdeveloped communities of Brazil's impoverished northeast, where millions of people live without access to safe drinking water, electricity or medical care. The country has long been characterized by extremes of wealth and poverty, but now even in the prosperous southeast, where Sao Paulo and Rio de Janeiro are located, authorities are reporting the virus' presence. That's particularly worrisome for officials in Rio, where the 2016 Summer Olympic Games are expected to draw millions of fans from around the world in August.