For the first time since March 2014 when the World Health Organization (WHO) was first notified of a rapidly growing Ebola outbreak in southeastern Guinea, the affected region went a full week without any new lab-confirmed cases, according to an update today.
The WHO, however, cautioned about a remaining risk due to several high-risk contacts linked to recent transmission chains that have been lost to follow-up in both Guinea and Sierra Leone.
The encouraging further drop in cases means the outbreak region has stayed below 10 confirmed cases for 11 straight weeks and comes just 2 days after the WHO's Ebola emergency committee recommended that the situation still warrants a public health emergency of international concern as defined by the International Health Regulations.
Guinea's drop to zero cases last week followed a spurt of four cases the week before, all of them with links to the country's last known transmission chain, based in Conakry's Ratoma area. The WHO said 509 contacts are still being monitored in three of Guinea's districts: Conakry, Coyah, and Forecariah.
The WHO warned that over the past 42 days, responders have identified but haven't been able to trace 290 contacts from four of Guinea's districts: Conakry, Coyah, Dubreka, and Forecariah. The country's four most recent cases were reported in late September from two villages in Forecariah district. All were infected by an unregistered contact of a probable case linked to the Ratoma transmission chain.
Door-to-door case finding efforts have been under way in Conakry and in several villages in Forecariah district to address the risks posed by the contacts who were lost to follow up.
Meanwhile, Sierra Leone has gone 3 weeks without a new case, and as of Oct 4 all contacts related to the country's last two known transmission chains completed their monitoring. The last patient was discharged from treatment in Kambia district on Sep 26, which started the country's 42-day countdown toward Ebola-free status.
Officials, however, still haven't been able to trace two high-risk contacts, one each from Bombali and Kambia district. The WHO said responders will continue to search for them until 42 days have passed since the last case in each district.
Overall, the number of confirmed, probable, and suspected Ebola cases in the two countries and Liberia is at 28,421 cases, with Sierra Leone reporting the most illnesses, followed by Liberia. So far 11,297 deaths have been reported, with the highest number in Liberia, followed by Sierra Leone.
No new healthcare worker infections have been reported since Aug 26, keeping that total at 881, with 513 of them fatal.
Oct 7 WHO situation update
Oct 5 CIDRAP News scan "WHO committee continues Ebola emergency, temporary measures"