(NEW YORK) -- A deadly, undiagnosed disease that has been spreading in one region of the Democratic Republic of Congo (DRC) may be linked to malaria, health officials said Thursday.
As of Dec. 14, the latest date for which data is available, 592 cases have been reported with 37 confirmed deaths and 44 deaths under investigation, according to the Africa Centres for Disease Control and Prevention (Africa CDC), the public health agency of the African Union.
Over the last week, 181 samples from 51 cases were tested in a laboratory, Dr. Ngashi Ngongo, Africa CDC chief of staff, said during a Thursday press briefing.
Laboratory testing showed 25 out of 29 tested were positive for malaria. Additionally, rapid testing showed 55 out of 88 patients were positive for malaria.
Ngashi said there are two hypotheses: The first is that the undiagnosed disease is severe malaria "on a background of malnutrition and viral infection" and the second is the disease is a viral infection "on a background of malaria and malnutrition."
Malaria is a serious disease caused by a parasite that infects a certain type of mosquito, according to the U.S. Centers for Disease Control and Prevention (CDC). Most people contract malaria after being bitten by an infected mosquito.
Most cases of malaria occur in sub-Saharan Africa, but it also occurs in parts of Oceania and in parts of Central and South America and Southeast Asia.
Malaria can be deadly if is not diagnosed and treated quickly, the CDC said.
What we know about the disease
The disease first appeared in a remote area in the province of Kwango, in the southwestern part of the DRC on the border with Angola, according to Africa CDC.
The first case was documented on Oct. 24. Patients have been experiencing flu-like symptoms including fever, headache, coughing and difficulty breathing as well as anemia, Africa CDC said during a press briefing earlier this month.
A plurality of cases, or 42.7%, have occurred in children under 5 years old. This age group also has the largest number of deaths, with 21 so far, data from Africa CDC shows. Children between ages 5 and 9 make up the second highest number of cases
Africa CDC said in a post on X earlier this month that it took five to six weeks after the first case was reported for local authorities to alert the national government, highlighting "gaps in Africa's disease detection systems: limited surveillance, testing delays & weak lab infrastructure."
-ABC News' Youri Benadjaoud contributed to this report.