As if civil war and a barely existent infrastructure were not enough, South Sudan is suffering an outbreak of a disease with symptoms disturbingly similar to Ebola. Health researchers are confident that the disease is not only not Ebola, but is not likely to spread at anything like the same rate. Still, that is only limited comfort for the sick and those with the responsibility to keep the population healthy.

On May 19, the World Health Organization announced that it had been notified by the South Sudanese health authorities of 51 suspected cases of hemorrhagic fever from Aweil North and Aweil West, counties in the northern part of the world's newest independent nation. Ten people have died. Three-quarters of the cases were in people aged less than 20, although in-state, where almost two-thirds of the population are under 24, this may be more coincidence than the sign of a disease that targets the young.

Reported symptoms include unexplained bleeding, fever, and vomiting. In cases where medical treatment could be provided symptoms resolved quickly, but in a nation with some of the most limited medical resources in the world this hasn't always been possible.

The reports follow an even larger number of cases, and deaths, in neighboring Darfur last year.

The relatively easy resolution of the condition, with treatment, differentiates the disease from Ebola, but possibly more importantly, it doesn't seem to spread person-to-person, the capacity that inspired terminology such as “going viral”.

Whether the cause is viral, bacterial or something else remains unknown, however. Samples taken from 33 patients tested negative for Ebola, and for other viruses and bacteria known to cause hemorrhagic fever. The only known pathogen that was detected in multiple cases was O'nyong-nyong, a mosquito-borne virus. However, not only does O'nyong-nyong have much milder symptoms, but it was only found in five cases.

With no evidence of person-to-person spread, the mysterious disease is unlikely to cause the sort of chaos unleashed by a disease like Ebola, where medical workers were highly vulnerable. On the other hand, having no idea what is causing the condition makes it almost impossible to be confident it is under control.

Aid agency Médecins Sans Frontières told National Public Radio they are “watching the situation fairly closely,” and “could deploy very rapidly if necessary in the area, but for the moment it does not seem that it is required.”

Nevertheless, with the experience of the Zika virus, once thought largely harmless, dominating the news, it is hard to write off the threat from any poorly understood disease.