Situation Report

The C.D.C. changes testing guidelines to exclude those exposed to virus who don’t exhibit symptoms.

The Centers for Disease Control and Prevention quietly modified its coronavirus testing guidelines this week to exclude people who do not have symptoms of Covid-19 — even if they have been recently exposed to the virus.

Experts questioned the revision, pointing to the importance of identifying infections in the brief window immediately before the onset of symptoms, when many individuals are thought to be most contagious.

Africa declared free of polio Nigeria is now rid of wild polio having had more than half of global cases less than 10 years ago. BBC News

Africa has been declared free from wild polio by the independent body, the Africa Regional Certification Commission.

Polio usually affects children under five, sometimes leading to irreversible paralysis. Death can occur when breathing muscles are affected.

Twenty-five years ago thousands of children in Africa were paralysed by the virus.

The disease is now only found in Afghanistan and Pakistan.

There is no cure but the polio vaccine protects children for life.