The World Health Organization has declared a public health emergency of international concern over a rare strain of the Ebola virus spreading across DR Congo and Uganda. The strain, known as Bundibugyo, has no approved vaccine or specific treatment.
More than 500 cases and 131 suspected deaths have been reported.
The Bundibugyo strain has a mortality rate of 30 to 40 percent, lower than the Zaire strain's 90 percent. However, the lack of vaccines and clinical experience makes this outbreak particularly dangerous. Cases are appearing in remote, conflict-affected areas, and overlapping outbreaks of malaria and cholera complicate detection.
The WHO's emergency declaration is meant to mobilize international funding and support. Countries in Asia, including Singapore, Thailand, and Indonesia, have stepped up airport surveillance. The United States has begun screening passengers from affected areas and suspended some visa services. Experts say airport screenings are effective and urge travelers to practice good hygiene but not to panic.