BROADENING HOST RANGE IN A GLOBALIZING WORLD Monkeypox virus emergence and threat Laudisoit Anne*, Gryseels Sophie, Mussaw Moise, Rouquette Olivier, Van Houtte Natalie, Musaba Prescott, Chantrey Julian, Begon Mike, Muyembe Jean Jacques, Leirs Herwig and Verheyen Erik *anne.laudisoit@liverpool.ac.uk
THE ERADICATION OF SMALLPOX : A WHO SUCCESS STORY 18th century : EUROPE 1/10 children died of smallpox 1950 50 million infections in the world 1977 Last natural infection 1979 Laboratory infection 33 endemic countries 1200 millions people 2 million deaths 1967 START eradication campaign 8th May 1980 ERADICATION TOTAL COST: 320 m$ SAR 80% CFR 25-40% R 0 3.5-6.9 How was it possible? VACCINE AVAILABLE VACCINEES IDENTIFIABLE VACCINEES VACCINATING MANPOWER - FUNDS NO ANIMAL RESERVOIR No renewable source
The EMERGENCE OF MONKEYPOX : A VIRAL SUCCESS STORY N annual cases/total (1996-2010) 1958 captive primates 1980 Active disease surveillance 1980-1986 338 cases Cessation of surveillance 2005-2007 Active surveillance 760 cases 1970 First human DRC 1971 Three West African countries 1985 Isolation from squirrel 20-fold increase 1996-1997 OUTBREAK 511 cases N COUNTRIES PERIOD N 1 Cameroon 1976-1990 24 2 Central African Republic 1984 6 3 Democratic Republic of Congo Endemic 4 Gabon 1987-1991 35 5 Ivory Coast 1971-1981 11 6 Liberia 1970 4 7 Nigeria 1971-1978 21 8 Republic of Congo Sporadic 9 Sierra Leone 1970-2014 11 10 Sudan 2005 19 0,25 0,2 0,15 0,1 0,05 14263Cases 243 HZ 0 1995 2000 2005 2010
MONKEYPOX VIRUS AND HOST RANGE RESERVOIRS OR NOT? THAT S THE QUESTION Species Confirmed human HMPX 4/4 (100) Rodents Cricetomys emini 2/7 (29) HA PCR positives/total (%) 40 Genus at least 65 species screened OXP-PCR : 137/462 = 29,7% INFECTED (DNA evidence) MKX-PCR : 12/108 = 11.1% INFECTED (DNA evidence) BROAD HOST TROPISM No difference between left and right bank WA-clade Sporadic case no interhuman transmission CB-clade Epidemic : interhuman transmission, increased virulence
MULTIPLE HOSTS AGENTS THE challenge to EID control 77% of livestock pathogens 91% of domestic carnivore pathogens 81.4% of animal diseases of greatest international importance infect multiple wildlife hosts The ability of pathogens to infect a wide range of hosts 1) is a risk factor for disease emergence 2) is key to eradication probability linked to hosts number, identity and ethology 3) requires more than presence/absence data transmission and contamination pathways spatial and temporal series cfr population dynamics interspecific network of interactions (camera trapping/behavior) frequency of inter- and intra-specific contacts evolution of agent-specific immunity
THE AGENT vs THE HOSTs POPULATIONs IMMUNE STATUS THE challenge to understanding disease dynamics R0 is NOT an intrinsic property of the infectious agent!!! Epidemic/Epizootic characteristic Virulence infectious agent (t x ) individual immune status herd-immunity R 0 for human MPX =? (based on few data : 0.83 to 1) Anybody knowing 1) R 0 for his/her «favorite agent» in WILD ANIMAL POPULATIONS? 2) the individual level of hosts immunity in target population(s)?
ASSESSING EPIDEMIC and EPIZOOTIC THREAT Does the agent portend pandemic/zootic potential? YOU ARE HERE EID do not respect borders, hide in suitcases, in multiple hosts EMERGENCE FROM LMIC without AFSCA -like controls BRIBE OR RACIAL PROFILING AT ENTRY / EXIT LMIC POINTS From a village in the heart of Africa to Brussels or...chicago IMPACT : 11/06/2003 Prohibition of all African rodents import into the USA (CDC) and sale, distribution, transport, or release ban of prairie dogs and six specific genera of African rodents within the USA (FDA).
Key points to discuss in a ONE HEALTH CONTEXT R&D «Prevention Preparedness Response» Research & Development (R&D) 1) VIRUS : WHY SUCH A BROAD HOST RANGE? Evolution towards human pathogenicity of Orthopoxviruses 2) WHAT ABOUT MPXV in domestic animals in DRC? In Africa? 3) HUMAN POPULATIONS : SPORADIC VS EPIDEMICS Disease dynamics and immunity VS source, mode and strain influence on R 0? Are the recovered hosts immune for life? Need a better surveillance - case notification and RDT in the field VACCINE DEVELOPMENT?! Coordinated «Prevention Preparedness Response» (PPR) We CANNOT wait the (next) big epidemics/zootics to hit the fan! What if shit happens? Example : Ebola outbreak Urge for a ONE HEALTH coordinated approach at ALL levels!!!