Blog dedicated primarily to randomly selected news items; comments reflecting personal perceptions

Thursday, July 07, 2016

Brazil's Zika Epidemic

"If she [a pregnant woman] was infected at 18 weeks, you're not going to see anything [abnormalities] at 19 weeks -- time needs to pass before things evolve."
"That's what we've been trying to say to people -- it's not about the head size. It's about brain growth."
"As a rule, children with severe brain damage have shorter lifespans. It depends on the degree of damage."
"That's essentially the conversation that one has to have. If we have absolutely no ultrasound features of concern but evidence of the woman having Zika, we have to be genuine and say, 'it's great that we don't see any abnormalities but we can't tell what future time will show."
Dr. Deborah Money, professor of obstetrics and gynaecology, exec. vice-dean, faculty of medicine, University of British Columbia

"It was crazy. The population of mosquitoes [in Rio de Janeiro] is huge."
"For the first time, the Olympic and Para-Olympic Games are being held in a region that is dealing with a viral epidemic. All necessary [protective] measures should be utilized."
Dr. Babak Shadgan, chair, world wrestling federation medical commission, Vancouver

Dr. Shadgan, in his visit to Rio, discovered that there was nowhere that the Aedes aegypti mosquitoes, carriers of the Zika virus, aren't present, indoors as well as outdoors, in overwhelming numbers. He and an American colleague wrote a position paper published in the Clinical Journal of Sports Medicine, urging all national sport teams to do as the South Koreans are preparing their athletes for, to ensure optimal safety during the games.

To design and produce sport wear with fabric impregnated with insect repellent, to consider covering arms and legs with specially designed outfits. This is the first Olympics ever where international public health experts advocated cancelling the Games because of the Zika outbreak. Their argument is that the epidemic cannot be contained; the half-million international attendees could carry the virus back with them from Rio to their homes around the world.

And the organizing committee of the Olympics has, for the first time in its history, licensed an official supplier of mosquito repellent, to be provided at no cost to all competitors. Those who might become infected may have no symptoms whatever and slough off the infection, while others have the potential to be dreadfully affected by it.

Not only does the virus cause microcephaly, the birth defect that leaves babies with abnormally small heads and developmental problems; it is also responsible for increasing the risk of Guillain-Barre syndrome, causing partial paralysis. But it is the dire effects on newborns that concern most health scientists. It is one thing to monitor women who have been exposed either during or before pregnancy, but there are complicating factors.

In Canada, there have been 137 confirmed cases of Zika, 79 of whom are female. Those who are pregnant are monitored with regular ultrasounds checking for skull abnormalities. But if a woman has been exposed well into her pregnancy that detection of something gone awry could occur when she is well advanced in her pregnancy.

Therein lies another dilemma, the choice of late-term abortion to allay fears of possible brain damage. And then again, even if a foetus's skull is determined to appear normal in an ultrasound, brain damage might still have occurred, so how to respond? There is, it appears, "no defined gestational age" when micocephaly can be considered to be no longer a threat, as far as the Public Health Agency of Canada's scientists can see.

Researchers studied 602 liveborn babies with definite or probable Zika in Brazil, to discover one in five had a head circumference within what is considered to be normal range. Zika brain damage can occur outside the physical reality of microcephaly. The journal The Lancet published the study confirming that Zika brain damage can occur in babies whose heads are a normal size and configuration.

If and when brain damage occurs, it ranges from visual or hearing abnormalities to "very, very severe brain growth restriction", along with conditions such as cerebral palsy, said Dr. Money. That Zika can be hidden throughout most of a pregnancy does occur, where months pass before there are any detectable symptoms of abnormal skull or brain growth, revealed by ultrasound.

And while it's all very well to avoid travelling to geographies where the mosquitoes abound and the virus has become epidemic, a growing number of cases have surfaced indicating that transmission has taken place through sexual congress.

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