The unexplained illness has infected 31 people and claimed the lives of 13, the World Health Organization (WHO) reported
Samples from four patients who died have tested positive for meningitis C, Liberia's Health Ministry told the WHO Monday. This points to the bacteria Neisseria meningitis as the likely cause of the illnesses, though investigations are ongoing to confirm it, the WHO said.
The infection is spread by close contact with infected people. Health officials in Liberia have been isolating suspected patients, tracing contacts, requiring safe burials and engaging with community and religious leaders to raise awareness, WHO spokesman Tarik Jašarević said.
An effective vaccine is available. While investigations continue, Liberian health officials are looking into vaccination options to prevent further cases, the WHO said.
The US Centers for Disease Control, which received blood, urine and plasma samples from the first patient believed to have died in this cluster, this week is sending meningitis laboratory scientists and epidemiologists to Liberia to assist investigations and to confirm whether meningitis is to blame, spokeswoman Kristen Nordlund told CNN in a statement.
"Based on what is currently known, there is no direct threat to the United States," she said.
Child dies after funeral
Events began on April 23, after an 11-year-old died within an hour of being admitted to a hospital with diarrhea, vomiting and confusion. The child had attended a funeral of a religious leader the previous day in Greenville, Sinoe County, according to the WHO.
Liberia's Health Ministry quickly ruled out Ebola, yellow fever and Lassa fever.
Then others who had attended the funeral in grew ill, the WHO said. The only person who has gotten sick but did not attend the funeral is the partner of a man who had been at the event; that man died April 29 in a Monrovia hospital.
"Timing of the events, duration between disease onset and death, higher case fatality among children are all suggestive of ingestion or exposure to a contaminant," CDC spokesman Tom Skinner said
in early May.
Liberian officials initially declined to link the illnesses with the funeral.
Fighting meningitis in Africa
There are six strains of meningitis bacteria that can cause epidemics: A, B, C, W, X and Y. Type A dominates in Africa, particularly across northern parts of the continent known as the meningitis belt, though the other types can appear.
Nigeria, which is about 1,200 miles east of Liberia, is currently fighting the largest meningitis C outbreak it has seen in nine years, according to Doctors Without Borders
. As of the end of April, the outbreak had claimed 839 lives among more than 9,600 suspected cases since late 2016, the group reported.