Ebola and Measles Control Activities in Guinea, Liberia and Sierra Leone

Context

In 2014, Guinea, Liberia and Sierra Leone experienced an unprecedented Ebola virus disease (EVD) outbreak. By the end of 2014, the three countries had reported a total of 20,206 cases1. The outlook began to improve towards the end of Jan 2015 with less than 100 confirmed new cases per week2. In Liberia, there have been no reported cases during the first week of March, 2015.

Each of the affected countries have endured massive disruption of daily life and interruption of regular health services, including immunization, as nearly all health resources were shifted to the Ebola response. In Guinea, Liberia and Sierra Leone, which typically are short of health workers, a total of 830 confirmed health worker infections have been reported with 488 reported health worker deaths. Health clinics that remained open, faced communities deeply reluctant to visit for fear of Ebola infection. In Liberia for example, only 50% of health facilities were providing immunization services in the fourth quarter of 2014.

The Threat

Measles is far more contagious than Ebola and is associated with significant mortality, particularly among children under the age of five years. On average, a case of Ebola results in two new infections, while one measles case can generate up to 18 new cases among susceptible persons. While Ebola has killed nearly 10,000 people during this current outbreak3, a second crisis is looming – many more thousands will die if measles outbreaks are not prevented.

The most effective means of avoiding large measles outbreaks is the resumption of immunization services with careful and ongoing assessment of the EVD situation in each of these three countries. The Measles & Rubella Initiative (American Red Cross, U.S. CDC, UN Foundation, UNICEF, WHO) has been supporting the governments of Guinea, Liberia and Sierra Leone to prevent measles outbreaks.

Interventions:

  • Using the standard M&RI Risk Assessment Tool, a measles transmission risk assessment was conducted in September 2014 in Guinea, Liberia and Sierra Leone
  • In October 2014, WHO issued the policy statement, “Guidance for Immunization Programmes in the African Region in the Context of Ebola” to:
    1. Maintain immunization services and use immunization contacts and surveillance system as opportunities to educate and monitor for Ebola;
    2. Provide guidance on infection prevention and control during vaccination;
    3. Implement activities to increase immunization coverage in areas where feasible
  • Because of high risk of Ebola transmission, advised Liberia and Mali governments to postpone nationwide measles SIAs originally scheduled in the fourth quarter of 2014.
  • Continued close monitoring through surveillance of vaccine preventable diseases through the established surveillance network. Sierra Leone and Guinea have existing WHO accredited Laboratories to assist with surveillance while Liberia was supported by the Regional Reference Laboratory in Abidjan (Cote d’Ivoire).
  • Gavi, the Vaccine Alliance committed up to USD $45 million to assist with the recovery of health systems and immunisation services for all vaccines in the countries affected by the outbreak. Since 2013, Gavi has provided funding to the M&RI for outbreak response and other emerging needs.

 

The risk assessments indicated that there was an accumulation of large cohorts of unvaccinated children in all three countries with potential for significant measles outbreaks. Measles SIAs targeting children <5 years old were conducted in Guinea and Sierra Leone in 2012, and in 2011 for Liberia. For Guinea, an outbreak response immunisation covering 15 out of 34 districts was carried out in early 2014. Because of these activities from 2011 through early 2014, the largest immunity gaps are in children between 1 and 3 years of age. In addition, older age groups still remain vulnerable if they have not received 2 doses of measles vaccine.

However, up until the end of 2014, Ebola transmission was so intense in Guinea, Liberia and Sierra Leone that mass campaigns or large scale immunisation activities were deemed too high-risk and were deferred, given their potential for exacerbating EVD transmission.

Specific interventions by country

Liberia

The evolution of the EVD picture in Liberia has shown the greatest improvement and immunization activity planning has begun with the following activities:

  • Starting in December 2014, M&RI partners on the ground supported a multi-antigen Periodic Intensification of Routine Immunisation (PIRI) activity in 3 phases
  • M&RI provided a grant of USD $700,000 to pre-position 360,000 doses of measles vaccine in Monrovia, and support immunisation operations and surveillance strengthening
  • M&RI partners are participating in the in-country decision regarding scheduling of a nationwide measles campaign. The special challenges of organizing and implementing a high quality measles campaign will need to be overcome in order to conduct a high quality SIA.

Since January 2015, there have been 39 suspected measles cases reported in Montserrado. As of early March, lab equipment and reagents were being rushed to the country to test samples to confirm if these cases are measles.

Guinea

Following the measles outbreak late 2013, Guinea vaccinated 1.6 million children aged 6 months to 9 years in 15 districts in early 2014. In November and December 2014, M&RI partners supported activities to step up routine vaccinations in communities that had not reported a case of Ebola for 42 days.

Currently, the country is experiencing a confirmed measles outbreak with 305 suspected measles cases reported in the first eight weeks of 2015 in 10 health districts. From a total of 24 samples, 14 were positive for measles IgM confirming that this outbreak is indeed measles. The country team (WHO/MOH/UNICEF) is planning to conduct outbreak response vaccination in the affected districts and may seek support from the Measles & Rubella Initiative Outbreak Response Fund.

Sierra Leone

Sierra Leone reported a total of 153 cases of measles in 2014 – this relatively low number is likely due to the collapse of surveillance systems. In February 2015, a surveillance records review in 7 out of 14 Districts detected 864 cases in 2014. During February 2015, more than 50 measles cases were reported in Bombali districts, with unconfirmed suspected cases in other villages.

Unfortunately, the EVD situation remains volatile and widespread in Sierra Leone, which reported 81 new confirmed EVD cases in the first week of March, limiting the possibility of enhanced immunization activities. Nevertheless, the Ministry of Health is working with immunization partners to strengthen routine immunization services, mitigate outbreak risk, and respond to reported measles cases. An evaluation is underway to assist the country to decide when it will be feasible to conduct an under 5 year measles campaign.

Moving Forward

The disruption of the social fabric and health service delivery, and the resulting decline of immunization coverage has left hundreds of thousands of children vulnerable to vaccine preventable diseases like measles in Liberia, Guinea and Sierra Leone. The indirect impact of addressing the Ebola crisis may prove more deadly than the virus itself in terms of potential measles deaths.

Optimism that the worst of the Ebola crisis is waning has been tempered by recent WHO reports that the number of new cases of EVD are rising across Sierra Leone and Guinea for the second week running5. Preventing measles outbreaks in a rapidly changing Ebola situation in Western Africa will require careful reflection on the most effective immunization activities while weighing risks to communities and health care workers, and a closely monitored and tailored approach for each country.

The Measles & Rubella Initiative is working closely with each country and our partners to resurrect routine immunization programs, strengthen case-based surveillance, and provide financial and technical assistance for wide age multi-antigen mass campaigns. In doing so, we are dedicated to rebuilding immunization systems to ensure communities have regular opportunities to access essential vaccines to protect their children in a post-Ebola era.

Note: EVD reported information accessed on 11 March, 2015: https://apps.who.int/ebola/en/current-situation


FOOTNOTES
1 | WHO | EBOLA RESPONSE ROADMAP SITUATION REPORT | DEC 2014
2 | WHO | EBOLA RESPONSE ROADMAP SITUATION REPORT | JAN 2015
3 | WHO | EBOLA RESPONSE ROADMAP SITUATION REPORT | FEB 2015
4 | Gavi, the Vaccine Alliance, Report to the Board, 10 – 11 December 2014, page 2. “Accelerating Access to Ebola Vaccines and Country Perspective.”
5 | WHO | EBOLA RESPONSE ROADMAP SITUATION REPORT | FEB 2015