WHO Releases New Details About Additional Cases of Ebola Virus Disease in Mali

As of Nov. 20, 2014, Mali has officially reported a cumulative total of six cases of Ebola virus disease, with five deaths. Of the six cases, five are laboratory confirmed and one remains probable as no samples were available for testing. These numbers include the 2-year-old girl who initially imported the virus into Mali and died of the disease on Oct. 24, 2014.

Intensive tracing and monitoring of the child’s numerous contacts, including many who were monitored in hospital, failed to detect any additional cases. All 118 contacts, including family members, have now passed through the 21-day incubation period without developing symptoms.

The virus was almost certainly re-introduced into Mali by a 70-year-old Grand Imam from Guinea, who was admitted to Bamako’s Pasteur Clinic on Oct. 25 and died on Oct. 27. He has been reclassified as a Guinea case, as he developed symptoms in that country. No samples were available for testing.

All five cases in this new outbreak are linked -- three directly and two indirectly -- to the patient in the Pasteur Clinic.

The first was a 25-year-old male nurse who worked at the clinic and was assigned to care for the Imam. He was hospitalized on Nov. 8. His case was laboratory-confirmed on Nov. 11 and he died the same day.

The second case was confirmed in a doctor who worked at the clinic and treated the Imam. He developed symptoms on Nov. 5 and was hospitalized on Nov. 8. Laboratory confirmation was received on Nov. 12. He is currently undergoing treatment.

The third case was a 51-year-old friend of the Imam who visited him at the Pasteur Clinic. He developed symptoms on Nov. 7 and died on Nov. 10 from an undiagnosed cause. He is the country’s single probable case.

The friend’s infection led to an additional two confirmed and fatal cases. The first was a 57-year-old woman who had direct contact with the friend. She developed symptoms on Oct. 29. She was admitted to another clinic on Nov. 11and then transferred to a hospital on Nov. 12. She died that same day.

The second case was the woman’s son. He visited yet another clinic on Nov. 5 and died at home on Nov. 14. Ebola infection was laboratory-confirmed in both cases.

A massive effort is currently under way to identify all potential chains of transmission, monitor contacts, and prevent the outbreak from growing larger. At present 338 contacts have been identified and 303 (90 percent) of these have been placed under daily surveillance. This rigorous “detective” work shows that the deceased nurse from the Pasteur Clinic had the largest number of contacts, at 98, including 75 family members.

As the successful experiences in Senegal and Nigeria show, aggressive contact tracing, which seeks to find and break every chain of transmission immediately after an imported case, can hold the number of additional cases to very small numbers and support a rapid end to the outbreak.

The Ministry of Health, with assistance from the WHO country office, has augmented the number of staff engaged in contact tracing by drawing on polio surveillance teams and using local medical students with training in epidemiology.

In addition, the World Health Organization (WHO) has deployed 10 epidemiologists through its Global Outbreak Alert and Response Network (GOARN). The country is also ramping up its capacity to perform exit screening at the Bamako airport.

The Imam was buried in his native village of Kourémalé, Guinea on Oct. 28. That event has now been investigated. Thousands of mourners may have attended the funeral. Some of them touched the body as part of the traditional funeral ceremony. About 300 contacts are being traced.

Experts in Mali and at WHO agree that Mali will remain at risk of further imported cases as long as transmission across the border is ongoing.

Source: WHO