Officials say Ebola outbreak in eastern DR Congo may have spread undetected before April detection

Why are officials worried the outbreak is larger than first reported?

Congolese officials and WHO representatives say the virus may have been circulating before 24 April, and a modeling analysis cited in coverage suggested substantial underdetection and said the total number of cases could already be higher than official counts indicate BBC,BBC,Aol.

Why is this outbreak especially difficult to contain?

Sources say the epicenter is in eastern Congo, where insecurity and frequent movement of people make contact tracing and surveillance harder. The Bundibugyo variant also has no approved vaccine, limiting the tools available compared with some past Ebola outbreaks Guardian,BBC,uol.com.br.

What does the WHO emergency declaration mean here?

The WHO's declaration of a public health emergency of international concern is its highest alarm level for an extraordinary health event that poses cross-border risk and calls for coordinated international action; in this case, it followed spread from DR Congo into Uganda NYT,Guardian,Hindustan Times.