Assisting with an early warning system for cholera in the WHOAFR

1. Assisting with an early warning systemfor cholera in the WHOAFR • Bradford Gessner, MD – PrimaryInvestigator Martin Mengel, MD - ProjectCoordinator • AnnualRegionalConference on Immunization • Dar-es-Salaam, Tanzania,December 10-12, 2012.

2. Outline • African cholera distribution • Cholera early warning system • Need • Characteristics • Limitations • Africhol methodology • Epidemiology and vaccine use • Way forward in strengthening cholera prevention and control in the WHOAFR

3. Is there a need for an early cholera warning system? • Minimizing deaths means early intervention • Most deaths occur early • Mobilization of health and public health workers • Mobilization of supplies • Organization of CTCs • Vaccine stockpile effectiveness means early identification • Short duration of outbreaks • Identification of high risk/target groups • Identification of other target districts/distribution of spread

4. Characteristics of early cholera warning system • Timely • Reasonable positive predictive value (reported cases are true cases) • Reasonable sensitivity at macro-level  outbreaks not missed • Data quality  enough data to identify risk groups individual level reporting with basic demographics • Acceptable to population and surveillance staff • Simple and flexible

5. Limitations of an early warning system • Even best system may not allow rapid enough response • Difficult to maintain high training/awareness/motivation levels • Intermittent and sometimes infrequent need • Worse at primary reporting levels • May become ever more problematic as cholera programs succeed • May need to cover entire country, or large areas. • May depend on cross-border cooperation

6. - Objectives • Overall objective • By working through MOH structures in 9 African countries, collect data for evidence-based decisions on cholera prevention • Specific objectives • create and support a consortium of organizations involved in the fight against cholera in Africa and the world • create an international network of cholera surveillance • present epidemiological data on cholera in Africa to public health policy makers in support of in-country surveillance activities • strengthen the capacity of target countries in outbreak investigations and laboratory diagnostics, and improve understanding of the dynamics of epidemics • conduct phylogenetic studies on the isolated strains

7. - Consortium Coordination • Consortium • Africhol is a consortium of nine member countries with implementation through MOH structures supported by a global consortium of public health organizations and technical institutions at the country level (AMP, AFENET, EPIVAC, CVD-Mali, U.S. CDC, WAHO, OCEAC, SACIDS, Univ. Marseilles) • External Advisory Board • The quality and scientific methodology of Africhol is overseen by a board of international experts on enteric disease research • Funding • Bill & Melinda Gates Foundation through April 2013 • Grant management • AMP manages the grant and coordinates project activities

8. - Methodology Country Togo Uganda HU Guinea H HC HU H = Hospital HC = Health Centre HU = Health Unit IvoryCoast Kenya HU HC HC 1 Cameroon Tanzania 2 DR Congo Mozambique • Organization of surveillance • Standard operating procedures • Standard laboratory diagnostics • Initial training of participants & site supervision • Out-fitting sites • Organization of information channels • Implementation of internal and external quality control at participating labs Increased surveillance zone – ongoing monitoring Otheraffected zones – Not activelymonitored Outbreak Investigations

9. Africhol collects extensive individual data and confirms each notification in the lab

10. Africhol also collects detailed environmental and socio-economic data Household investigation Data is entered in a unified database Environmental form

11. Vaccines and epidemiological situations

12. Oral Cholera Vaccines (OCV) • The 64th World Health Assembly endorses OCV use • A new, safe and effective oral cholera vaccine (OCV) WHO pre-qualified in September 2011 • OCV campaigns were conducted successfully in Zanzibar(2010) and in Guinea-Conakry (2011) • Two potential strategies • Reactive • Preventive • Cholera vaccine stockpile initiative

13. Summary of two available cholera vaccine characteristics

14. EndemicCholera – Dem. Rep. of Congo Eastern DRC experiences year-round cholera, with seasonal fluctuations If cholera is endemic and predictable and priority groups to target are known preventive vaccination. Cases Nmber of cases

15. Epidemic cholera: Mozambique Spatial clusters of cholera in Mozambique week 1, 2009 through week 19, 2011 Legend: • Clusters: red areas • Weekly cases: red line • Rainfall: bluecolumns Findings: • Clusters spread widely • Clusters spatially seperate • Outbreaks of short duration • 89% of deaths during first 6 weeks • 24% of outbreaks >10 weeks

16. Oral cholera vaccine use in Guinea-Conakry Epidemic with 7000 cases and 127 deaths since the index case on March 6th. MSF vaccinated 200 000 people with Shanchol oral cholera vaccine in the districts of Boffa (mainly) and Forécariah. Pre-established Africhol surveillance system monitoring long term vaccine impact Dose 1 Dose 2 Number of cases Dose 1 Dose 2 Number of cases

17. Early warning systems and reactive cholera vaccination • Reactive = rapid (<4 weeks) • Early determination of: • Risk/target populations • Likely direction of spread (e.g., waterways) • Indirect effect • Risk assessment • Early logistics organization • Cold chain/storage • Human resources • Two doses • Coordination with other interventions (case management, water chlorination) • Regulatory: in advance • Community education

18. Role of Africhol or other regional networks • Part of - not replacement for - national and sub-national systems • Can assist with: • Mobilizing response • Technical expertise • Standard methodologies/forms • Laboratory support • Outbreak investigation • Monitoring intervention impact • May facilitate cross-border cooperation • Forum for information exchange