nd Human Services Secretary Sylvia Mathews Burwell, CDC Director Thomas Frieden and Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases. </p>
            </p>

            <p class="paragraph">
                <p>On Thursday, the World Health Organization is scheduled to hold a briefing in Geneva. Director-general Margaret Chan has warned that the disease’s spread is “explosive.” She has described the circumstantial evidence connecting Zika to cases of microcephaly, in