Before Rwanda confirmed its first-ever Marburg virus outbreak, two initial cases were treated for malaria instead of the infectious haemorrhagic disease.

The Ministry of Health officially confirmed Marburg virus disease in Rwanda on Friday, September 27. In the days before that announcement, the two patients had arrived at an unidentified hospital seeking treatment for their deteriorating health.

Their symptoms resembled those of malaria, a factor that compelled the medics to test them for the disease and prescribe medication.

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After days of treatment, their condition deteriorated rather than improving. This raised concerns among the medics who were attending to them, compelling them to report the situation to Rwanda Biomedical Centre (RBC).

"Our surveillance in the hospital that was attending to the first suspected cases raised the alarm, saying ‘we are seeing two patients who are not responding to usual treatment,’” said health minister Dr Sabin Nsanzimana explained during a press briefing on Thursday, October 3.

Dr Nsanzimana noted that the medics had initially suspected that the patients had malaria since the Marburg virus symptoms are similar to those of malaria. These are for example high fever, severe headache, muscle and joint pain, fatigue and later on gastro-intestinal nausea and vomiting.

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What added to the confusion, he said, was that some malaria tests carried out on the patients had returned positive, which suggests that there was a co-infection of Marburg virus and malaria.

The first patient’s condition was deteriorating rapidly, prompting RBC and the National Reference Laboratory to step in for further examination.

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Blood samples were taken and tested using real-time reverse transcription polymerase chain reaction (RT-PCR) at the National Reference Laboratory.

The results confirmed the presence of the Marburg virus.

In response, health officials quickly initiated contact tracing, particularly among healthcare workers, taking into account key epidemiological cues, including the fact that Marburg virus symptoms appear between two to 21 days after exposure.

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"We went back to trace the contacts,” Dr. Nsanzimana said.

Over 400 contacts have been identified since and they are being monitored. PCR tests remain the definitive method for diagnosis.

Health authorities are still investigating the origin of the outbreak but have not yet determined its source. Minister Nsanzimana said that the index patient has not been identified.

More than 1,000 tests have been conducted so far.

As of October 3, a total of 37 cases had been confirmed and 11 deaths reported. The cases were spread across seven of the country’s 30 districts. Around 80 percent of the confirmed cases are healthcare workers.