Pictures of the infant Jose Wesley of Poco Fundo, Brazil, have been in the news throughout the world over the past few weeks, as his mother bathes him in a bucket, his tiny head revealing the birth defect from which he suffers – microcephaly, an unusually small head and brain in newborns. He has become the face of birth defects that have been associated with the mosquito-borne zika virus.
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The connection between the microcephaly and the virus is still unclear, but the leap in the number of infants born with this life-threatening condition has jumped more than 20 times the norm – about 4,000 cases in Brazil as opposed to the previous annual average of 150. It has sown panic in Brazil, where abortion is allowed only in extreme cases.
The panic has already crossed Brazil’s borders, as the virus has been reported in 21 Latin American countries, and the World Health Organization has announced that it expects the virus to spread to other countries in which the Aedes aegypti mosquito is prevalent. These areas include the Americas (except for Chile and Canada), all the tropical and sub-tropical counties in Africa, the Indian subcontinent, Southeast Asia, parts of Australia and Oceania.
There are no mosquitos of this species in Israel; however, four cases of Israelis who contracted the virus elsewhere have been reported. Last week a two-year-old who returned with her family from Colombia was diagnosed, and now it is reported for the first time here that the baby’s mother and apparently two other relatives also caught the virus.
Health Ministry director general Prof. Itamar Grotto says there is no cause for panic, and no concern over a local outbreak of the virus. Rather, he said the concern is over pregnant women who travel to infected countries.
The ministry also said that while the Ades aegypti mosquito is an efficient carrier of yellow fever, chikungunya, viral encephalitis and West Nile and dengue fever, it is less able to transmit the Zika virus.
West Nile and dengue have been spreading around the world and exist now in Israel because they are transmitted by the Asian tiger mosquito, Aedes albopictus, which was first noticed in Israel in 2002 and is now biting Israelispractically nationwide. Whether albopictus can spread zika is not entirely clear. But in any case, the Health Ministry said “at this time of year, Aedes albopictus is not active at all and so there is actually no risk during these months.”
Prof. Eli Schwartz, director of the Center for Geographic Medicine at Sheba Hospital, Tel Hashomer, agrees that this is not the season for the mosquito, but neither is this the end of the story. The Asian tiger mosquito can transmit the disease, Schwartz said, “and so potentially if many travelers come back to Israel who caught the virus, this could happen,” he added.
Schwartz said that “the mosquito needs blood every 10 days at most, preferably human blood. The moment it bites, the virus that is in its stomach passes on to the next human.” Thus, Schwartz said the spread of the virus to Israel – first by travelers bitten abroad and then by local mosquitos – is definitely a possibility.
This usually benign virus is now back in the news because of its possible connection made by Brazilian health authorities to the spike in microcephaly. The connection was made because of the number of babies born with the condition whose mothers experienced a rash during pregnancy, one of the symptoms of the virus.
“The connection is still not 100 percent clear,” said Dr. Leslie Lobel, a virologist at Ben-Gurion University. “But I think the directives to pregnant women not to travel to those countries are right so as not to take an unnecessary risk.”
Prof. Gustavo Malinger, head of the gynecological ultrasound unit at Ichilov Hospital, joined a medical team in Brazil about two months ago to check two women and their fetuses, due to be born within a week of their visit. “In both cases we found very damaged brains, really destroyed, and small heads. Not only the brain; in one case we found damage to the eyes as well,” Malinger said.
He said that from tests the team carried out, “We believe that microcephaly is apparently only one outcome of infection with the virus, and in some cases the heart and skeleton are also affected.”