Field research to iden/fy infec/ous agents in animals and the environment to a6empt to predict emergence John S Mackenzie Plenary session 3: Policies and Strategies to Meet the Challenge of Emerging Disease Threats Through Preven@on, Preparedness and Response
Global distribu@on of rela@ve risk of an EID event. Jones et al (2008) Nature 451:990-3.
Implemen@ng a Targeted Surveillance Strategy in high risk loca-ons for emergence
Human Surveillance 1301 "high risk" individuals at the human-wildlife interface within Guangdong Province (China) Hospital-based surveillance studies for encephalitis and hemorrhagic fevers of unknown origin (China). FUO hospitalized patients and factory workers (Indonesia). US-CDC, Thai-MOPH, AFRIMS, and Thai NIAH collaboration - 400 patients with fever and animals from associated areas. (Thailand) Integrated human and wildlife surveillance CDC and ICDDR,B (Bangladesh)
Sampling and Tes@ng in GAINS Training in surveillance and wildlife disease across veterinary and public health sectors Establishing infrastructure for sample handling, capacity in laboratories and implemen@ng diagnos@c tes@ng
Longitudinal Studies of Individuals Occupationally Exposed to Animals
PATHOGEN DETECTION AND DISCOVERY HUMAN- WILDLIFE INTERFACE: COLLECT SAMPLES RELEVANT TO TRANSMISSION UNBIASED AND PAN- VIRUS FAMILY MOLECULAR ASSAYS: DEEP- SEQUENCING, PCR, and MICROARRAYS PATHOGEN DISCOVERY: FOLLOW- UP SURVEILLANCE AND CHARACTERIZATION
A staged strategy for pathogen discovery Lipkin MMBR, 2010
Wildlife Sampling To Date
PREDICT strengths and successes Strengths: - An exci@ng development with the possibility of finding a pathogen at an early stage if a subject becomes ill, or by detec@ng novel viruses; - Over 200 new viruses have been detected; - It has provided an excellent surveillance system in areas not previously been subject to surveillance, but which have been suggested to be poten@al hot spots ; - It has a strong capacity building component for both laboratories and field scien@sts in countries with the hot spots; - A new pathogen was found in retrospect using material collected 2 years earlier, Bas- Congo virus, in a small outbreak in DR Congo 3 pa@ents, two school age pa@ents who died from a haemorrhagic fever, and their health carer who fell ill but survived; a novel rhabdovirus was found by deep sequencing technologies.
PREDICT - weaknesses Weaknesses: - The process cannot PREDICT a new human pathogen; there is no mechanism available to indicate the pathogenic poten@al of the virus, nor the risks associated with cross- species transmissibility. - Any system that employs deep sequencing or similar current molecular techniques is unlikely to be sufficiently rapid or sensi@ve for pathogen detec@on.
Hendra virus: A virus of fruit bats (flying foxes) transmiued to horses (spillover host) and humans. An excellent example of One Health in ac@on in the field
Hendra virus A virus of pteropid fruit bats which spills over to cause a highly fatal acute, febrile respiratory or neurological disease horses; Humans can be infected from the sick horses, and suffer severe, ocen fatal, pneumonia and /or encephali@s with mul@- organ failure infec@ons: Thus an excellent example of a One Health problem. Despite the involvement of many wildlife experts, veterinarians, public health prac@@oners etc,we can not predict the @me or place of an outbreak, nor do we know clearly the drivers of spill- over events.
Environment interfaces: the natural product and extrac@on industries such as mining and logging Can we predict emergence and should we be more ac@ve in these scenarios? Environment/ Ecosystems Animals Humans
Environment interfaces: The global spread of Aedes albopictus through interna@onal trade in used car tyres Environment/ Ecosystems Animals Humans
Chikungunya Outbreak in Italy, 2007 CasYglione di Ravenna and CasYglione di Cervia Bologna three cases of local transmission 334 suspected cases, 204 lab confirmed. Outbreak iniyated by traveler from Kerala. Cases also in Rimini and Ravenna
Conclusions Field research to iden@fy new agents to ahempt to predict emergence We need to seek novel ways to try to detect and especially predict or rapidly determine whether newly described agents have pathogenic poten@al. This might not be possible for those agents for which only gene@c fragments have been iden@fied. Disease emergence has been associated with a number of anthropogenic factors, including land changes, so target areas and ac@vi@es should include the extrac@on industries. We need to remember that the environmental interface also has many factors precipita@ng poten@al pathogen emergence and spread not least the spread of mosquitoes and other vectors to new habitats and geographic areas. These and other issues form the basis of some of the breakout sessions acer the coffee break!
and another story In late summer 2001 an episode of avian mortality was observed in Austria Reminiscent of the begining of the West Nile Virus epidemic in the United States in 1999 Birds of different species died suddenly Mainly blackbirds (Turdus merula) were affected, leading to a significant reduc@on of the blackbird popula@on, but also barn swallows and owls
Usutu virus an unexpected incursant A virus was isolated in culture, sequenced, and shown to be an African virus, Usutu virus, a mosquito- borne flavivirus in the Japanese encephali@s serological group. This was the first @me Usutu virus had been found outside tropical or sub- tropical Africa. It had never been associated with bird mortali@es It had been isolated from mosquitoes, birds and occasional human cases with fever and rash.
Areas in Africa where Usutu virus has been identified
Usutu in Europe Since 2001, Usutu virus has caused outbreaks in Austria, Hungary, Germany, Switzerland, Serbia and Italy, with serologically posi@ve birds also found in the UK, Poland, Spain and the Czech Republic. In 2010, evidence of co- circula@on with West Nile virus. At least three incursions of virus from Africa appear to have occurred in central Europe and Italy and a further incursion into Spain. Its role in human disease remains uncertain: five human infec@ons were reported in 2009-10; viral RNA was detected in a pa@ent with rash in Austria; and in 2009 neuroinvasive Usutu infec@on was reported in two immunocomprimised pa@ents (both of whom had received blood transfusions) in Italy, and virus was recovered from the blood of one pa@ent.