Factors Leading to Uncertainties

Possible effects of different and simultaneous arbovirus infections in Brazil

When Zika virus arrived in Brazil

Why the Zika virus outbreak occurred in Brazil

Specific determinants in Brazil and in the Brazilian Northeast not known

Population immunity and occurrence of disease over time

Alternate causes for microcephaly and unknown exposure to these causes

No certainty of exposed numbers or exposure rates

Risk of microcephaly not determined

Lack of accurate and universally available differential laboratory diagnosis for Zika virus, dengue virus, and Chikungunya

Different hazardous effects on fetal brain at different periods of pregnancy

Characterization of other types of transmission other than vector transmission

Inaccurate notification

Unknown exposure to larvicides in drinking and stored water

Unknown risks related to larvicide and insecticide exposure

Suggestions for Government and Organizations’ Risk Reduction Strategies for Populations and Communities

Approach to Zika with an “all hazards–whole health” outlook

Improvement of living and sanitary conditions

Adequate water supply and piped water

Sewage systems

Laboratory diagnosis confirmation for all probable cases of Zika

Differential diagnosis for Zika virus, dengue virus, and Chikungunya

Screening blood for transfusions

Adequate surveillance and notification

Counseling for pregnant women and women of reproductive age

Better vector-control strategies

Enhanced risk communication strategies

Improvement of health literacy

Seroprevalence studies and investigations into alternate causes of microcephaly and nervous system abnormalities

Comprehensive health care for women, children with Zika sequelae, and families

Suggestions for Individuals’ Prevention Strategies

Individual care and responsibility for the environment

Planned pregnancy and planned parenthood

Use of condoms

Pregnant women’s rational use of repellents and care to avoid mosquito bites