Zika cause microcephaly? CDC sought more
#Cosmoread: Still, Disease Control and Prevention (CDC), researchers at the Center for Study of Zika virus are collaborating with researchers in Brazil. Scientists rapidly spreading mosquito-borne virus, a harm fetal brain development that babies born with a small head and small brain, leading to the goal of course is incomprehensible.
In a recent press briefing, CDC director Dr. Thomas Frieden said, “With each passing day, Zika virus and is looking stronger and stronger cooperation between microcephaly.”
Now, the next there is actually a cause and effect link between the virus and microcephaly whether to investigate, the researchers called a case-control study will use a major type of research study, Frieden said.
Preliminary evidence of a causal link is emerging: The CDC recently analyzed two who died shortly after birth two pregnancies that ended in abortion in Brazil early infants with microcephaly, and collected brain tissue samples. All four mothers in the first trimester of pregnancy, such as fever and rash Zika infection symptoms, said.
Those lab results from the babies and abortion placental tissue in the brain tissue showed the presence of Zika virus. Microcephaly in the Zika virus and suggested a strong association between the risk of the uterus, according to a CDC report.
Further investigation of a causal link between Zika virus and microcephaly, the key is in the way that one of the researchers will use a case-control study, Frieden said. A case-control study, preliminary research yet to gather strong evidence of a link could provide, he suggested.
Using this type of study, researchers infants certainly microcephaly, is considered the “cases” and children who do not have birth defects, will identify as “controls.” Once investigators in each group is a large enough number, characteristics of infants and their mothers, many of the scientists, to tease out the differences between the groups may indicate a causal relationship, comparing environmental risks and laboratory testing the result can look at.
Search for clues
Currently, the CDC is collecting the information quickly and carefully all the scientific evidence of the link between Zika and microcephaly may help to establish the full picture that is working to evaluate, Peggy Honein, birth defects and growth CDC’s National center for the disabled in Atlanta said a pandemic.
Zika case-control study and a plan of microcephaly in Brazil is starting soon, and the CDC team has traveled the region to help in the research, Honein said. CDC also is expected to launch similar study in Colombia, and Puerto RICOL is working on a review of the cases, Honein added.
Brazilian researchers studied 400 women and 500 infants in the past few months, microcephaly, both with children (cases) of the total enrollment is expected to be included, and those without the condition (as control ), Honein told Live Science.
Researchers such as whether women during their pregnancies had symptoms of Zika virus, a quarter of these symptoms, and women such as rubella or other potential environmental toxin prenatal risk, or not, that may be risk factors, will examine the adverse birth outcomes, including microcephaly are strongly associated with, Honein said.
Whenever possible, researchers also found that these infections will be looking to see if any, laborato
ry confirmation, but scientists, whether infection symptoms experienced by women were at the basis of their evaluation needs, Honein said.
Between mid-2015 and January 2016, about 4,800 babies born in Brazil, suspected microcephaly, while less than 200 cases per year in the country before Zika outbreak were reported as was reported recently in the journal Lancet according to a newspaper. The outbreak began in early 2015 in the northeast region of Brazil.
However, although there has been a tremendous increase in suspected cases of microcephaly, Brazil far below the actual number of cases may have microcephaly. When laboratory tests, imaging exams and rigorous checks are completed by a number of health professionals can leave the Lancet study authors said.
Why case-control studies can provide clues
Microcephaly can be a difficult to monitor birth defects, different criteria are used to determine the definitions, because Honein said. She also said that researchers other viral diseases, such as rubella and cytomegalovirus infection in infants can cause health problems, infection during pregnancy are looking at the examples. Researchers use this information to create the Zika virus and its possible mechanism about microcephaly and are trying to understand more.
Case-control studies are widely used, especially for the study of infectious diseases, Stephen Morse of Columbia University Mailman School of Public Health in New York City, professor of epidemiology in the study of emerging infectious diseases he specializes in. Such studies are easy to a relatively small number of cases of the rare diseases that are efficient for data collection, he said.
When researchers want some quick answers are valuable for case-control studies, and studied for a suitable place to start accumulating information in these circumstances, Morse told Live Science. “But the trick is being able to control the group as a suitable match,” he explained.
A cohort study, people with time on exposure to risk factors of a disease caused by a group that is used to evaluate – as – other types of studies as microcephaly, for a rare disease that can take a long time to complete, said Morse. Probably a case controlled study could be completed in a few months, he said.
A case-control study can help you learn more information on microcephaly Zika infection in pregnant women and evidence of a causal relationship between consolidating, Morse said. Researchers in Brazil, pregnant women will collect information about many factors: your age; Socioeconomic status; Living conditions; Nutritional status; Such as lead, pesticides or toxins during pregnancy, the risk; And infection during pregnancy experienced. By doing so, researchers can sort out whether the Zika virus alone or other risk factors may be contributing to the birth defects in combination with, he explained.
Little is currently widespread or Zika virus infection in pregnant women in the population of Brazil is known about the spread, then to understand microcephaly Zika virus with pregnant women who were exposed to what percentage of the children born there was a need, said Morse.