4.14 Zika and microcephaly, continued. Exercise 4.12 discussed the 2016 CDC announcement that Zika causes microcephaly in newborns. The scientific evidence on which the CDC conclusion is based is available online. Typing DOI:10.1056/NEJMsr1604338 in a search engine will give you a link to the scientific article titled “Zika Virus and Birth Defects: Reviewing the Evidence for Causality.”

a. Table 2 in the article lists a number of criteria that can be used for establishing evidence of causation. Match the criteria from this table to the five criteria we listed for establishing causation in the absence of experiments. Are these five criteria met in the context of Zika infection and microcephaly?

b. Table 2 in the Zika publication lists experimental evidence as one way to establish causation. Is there experimental evidence available in the context of Zika infection and microcephaly?
How does this relate to the statement in the CDC announcement that “no single piece of evidence provides conclusive proof that Zika virus infection is a cause of microcephaly?”