Public health authorities are furiously working to contain and understand the origins of a cholera outbreak in Haiti that has killed more than 300 people and hospitalized almost 5,000.

Monday, the U.S. Centers for Disease Control shed light on how the food- and water-borne bacteria, which is not historically found in Haiti, may have spread to the earthquake-ravaged country.  According to CDC, the cholera strain matches strains commonly found in South Asia, adding a new level of legitimacy to speculation that United Nations peacekeepers from Nepal could have recently brought the bacteria to Haiti.

The outbreak appears to be centered around an area downstream from a U.N.base located above a tributary to the Artibonite River, where the Nepalese peacekeepers are based. Public health experts say they do not have enough information to determine what sparked the outbreak. The cholera strain common in South Asia could also have originated from India, Pakistan, or another country in the region.

“Although these results indicate that the strain is non-Haitian, cholera strains may move between different areas due  to global travel and trade,” Haiti’s Minister of Health Dr. Alex Larsen said in a statement. “Therefore, we will never know the exact origin of the strain that is causing the epidemic in Haiti.”

As leading experts point out, understanding the cause of the outbreak is not nearly as important as containing it.

“Our primary focus here is to save lives and control the spread of disease,” said CDC medical epidemiologist Dr. Jordan Tappero, the head of CDC’s cholera response team in Haiti.  “We realize that it’s also important to understand how infectious agents move to new countries. However, we may never know the actual origin of this cholera strain.”

According to the U.N. World Health Organization, the strains of Vibrio cholera 01 Ogawa isolated in Haiti showed resistance to antibiotics trimethoprim-sulfamethoxazole, furazolidone, nalidixic acid, and streptomycin.  The strains are sensitive to tetracycline, doxycycline and ciprofloxacin. The National Public Health Laboratory and CDC are currently working on genetic sequencing of the strains.

The World Health Organization is not recommending any travel or trade restrictions based on the outbreak.  “Travelers do not require proof of cholera vaccination, nor is there a need to screen travelers … There is no need to establish quarantine measures at the border, a measure that diverts resources and may hamper cooperation between institutions and countries,” WHO said in its most recent update.

Facilitated by poor water and sanitation, a lack of immunity among the Haitian population, and a short incubation period, the disease has spread rapidly–the first case was discovered just 12 days ago.

Authorities remain extremely concerned about controlling outbreak, especially as Haiti is preparing for Tropical Storm Tomas, which may potentially become a category 1 hurricane later this week. If disaster strikes the fragile region, it could further facilitate the spread of disease through flooding and the decimation of existing water infrastructure.