IPM & the West Nile Virus Epidemic, Greece, Terms to Know. Which is more dangerous? Florida and Thessaloniki, Greece

Transcription

1 IPM & the West Nile Virus Epidemic, Greece, Philip G. Koehler Margie & Dempsey Sapp Endowed Professor of Structural Pest Control FPMA Endowed Professor of Urban Entomology Entomology Department University of Florida Terms to Know Arbovirus: Arthropod-borne virus West Nile virus: Part of the Japanese encephalitis antigenic complex of viruses. It mainly infects birrds, but is known to infect humans, horses, dogs, etc. Sentinel chickens: used to monitor and detect certain arboviruses in an area Seroconversion: development of detectable disease antibodies in blood Mosquito larvicide: insecticide used to kill mosquito larvae Mosquito adulticide: insecticide used to kill adult mosquitoes Aerial mosquito treatments targeted using GPS and spray fate models defined in the lecture Which is more dangerous? 100,250 deaths per year 3 million deaths per year Florida and Thessaloniki, Greece State of Florida 16 million people 50,000 acres of rice-fields 23,000 acres natural wet-lands Thessaloniki 1 million people Bears Sharks 11 million acres of wetlands Snakes Lions Everglades 1.4 million acres of wetland 5.1 million people Mosquitoes prevent development in both the U.S. and Greece Wounds from bites Potential for disease transmission Annoyance Allergic reactions Mosquito-borne Diseases Impacting Greece Important arboviruses (arthropod-borne viruses): Malaria Chikungunya West Nile virus Yellow Fever Dengue Chikungunya from Italy & India Encephalitis 700 million people affected annually Florida spends annually $150,000,000 for mosquito control efforts West Nile Virus From Everywhere Malaria From Turkey 1

2 Mosquito Control in Greece and European Union Temephos was the main larviciding product (>10 years) In 2008 temephos was removed from the market A chitin inhibitor (diflubenzuron) has been used since Budget cuts decreased the size and duration of the program Larviciding ended in middle of July ,000-50,000 hectares treated (normally 70,000-80,000 hectares) Summary Less effective larvicide Treatment area ~50% smaller Treatment ended sooner Implementing IPM for Mosquito Control 6 Steps 1. Education & Communication 2. Identification 3. Monitoring 4. Prevention 5. Treatment Step 1 Education & Communication What is West Nile Virus? 1. Learn about the problem 2. Understand hazards 3. Cooperate with professionals Second Largest European WNV Epidemic Central Macedonia, North Greece, 2010 Number of patients diagnosed with neuroinvasive WNV infection according to date of symptom onset - Greece, 2010 WNV epicenter near Thessaloniki 2nd largest city of Greece ~1-2 million citizens cases Clinical July 6 July 15 Larviciding Discontinued Urban Areas Agricultural Areas July August September Larviciding program terminated due to budget cuts when epidemic started 2

3 Excessive adult mosquito populations - >100 mosquitoes/15 sec, - 90,000 females/cdc trap per night in ,000-30,000 females/cdc trap per night (summers 2008, 2009) Neuro-invasive WNV Lineage 2 (highly virulent strain) in Greece 2010: 261 neuroinvasive cases & 34 deaths Thessaloniki Central Macedonia, July 2010 Epicenter of the outbreak Neuro-invasive WNV (Lineage 2) Infections in Greece cases Thessaloniki Step 3 Monitoring 1. Mosquito presence determines strategies 2. Arboviruses (arthropod-borne disease) in birds can predict human epidemics Mosquito & Arbovirus Surveillance Program 2011 For the first time we developed an active mosquito/wnv surveillance system in Central Macedonia CDC light traps baited with dry ice Sentinel animals (chickens/horses) Purpose of the system was To determine the main nuisance/vector species in the area To guide mosquito control interventions to the right place, at the right time Decrease the likelihood or outcome of an epidemic Rice fields Thessaloniki: Major Mosquito Breeding Areas 2011 Aerial Identification of Mosquito Breeding Sites Discarded tires near the port River flooding Animal Facilities Flooding next to airport Flooded urban areas 3

4 2011 Mosquito & Arbovirus Surveillance Program Mosquito & Arbovirus Surveillance Locations Surveillance Unit Sentinel horses Sentinel chickens CDC light trap baited with dry ice Weekly sampling, 6 sentinel stations, 28 mosquito CDC traps Identification of Main Mosquito Species 17 species were identified in 2011 Aedes caspius Aedes vexans Cu. longiareolata Aedes dorsalis Aedes. albopictus Coquillettidia richiardii Aedes detritus Culex pipiens Uranotaenia unguiculata Aedes sticticus Culex. modestus Aedes cantans Culex theileri Aedes mariae Anopheles hyrcanus Also Malaria vectors Aedes zammitti Anopheles sacharovi June o population Cumulative mosquito Mosquito Population Levels Thessaloniki 2011 Culex mosquitoes, chicken seroconversions Culex mosquitoes, chicken seroconversions & human Cases Mean Temperature C Mean Temperature C Cumulative mosquito po opulation Tem mperature C Cumulative mosquito po opulation Tem mperature C 4

5 First report of WNV enzootic circulation in Greece for 2011 One month prior to human cases The virus was isolated and molecularly identified Identical to the WNV isolate from the 2010 epidemic Step 4 Prevention Keep pests from causing problems Remove breeding sources Exclusion Screens windows Prevent bites Change outdoor activity patterns Apply repellents Step 5 Treatment Apply the Smallest amount of The least toxic pesticide To the infested places to do the job GPS Modern Mosquito Control Equipment Spray Fate Model Real time weather probe Electric atomizer Turbine helicopter Precise & Recorded Treatments Equivalent of 1 aspirin tablet of insecticide per acre 5,000 ft offset Area A Wind:SSE 7.5m/s Aerial ULV Treatments in Response to WNV epidemic Aerial adulticide treatments were conducted Over the the epicenter of the outbreak Spray was only allowed >2 km away from populated areas Residue analysis was conducted at the end of the season on the rice crop No residues were detected 5

6 September 9th 2010 Product used: Aqua-K-Othrine (2% deltamethrin) 2,500 hectares treated BEFORE: Hundreds of mosquitoes!!!! 98% decrease 15 min after treatment: Almost no mosquitoes! Before: Hundreds of mosquitoes! 15 min after treatment: Almost no mosquitoes! Culex mosquitoes, chicken seroconversions & human cases 2011 Aerial treatments started after first human cases Mean Temperature C Cumulative mosquito po opulation Tem mperature C 6

7 Control Interventions in Response to WNV epidemic In 2010 Decision was made based on the presence of human cases In 2011 Decision was made based on Mosquito population density Seroconversions in sentinel animals Presence of human cases Conclusions WNV epidemics in Greece during 2010 & 2010 A mosquito IPM program was implemented in Greece during 2011 Step 1. Education: People were warned about mosquitoes and WNV Step 2. Identification: 17 mosquito species were identified Step 3. Monitoring: Mosquito populations increased in May Sentinel seroconversions were found in late June Determined that WNV lineage 2 strain had overwintered Human cases occurred one month after sentinel seroconversions Step 4. Prevention: Use repellents, stay indoors, destroy breeding Step 5. Mosquito control was initiated after first human cases and killed ~98% of mosquitoes, epidemic ended Questions What is the most dangerous animal (causing the most deaths) in the world? Where is Northern Greece (Macedonia [not the current country by that name]) and what is the name of its largest city? What are the specific breeding sites for vectors of West Nile virus? What are some methods of monitoring mosquito populations? What are some methods of monitoring arboviruses? When should do you decide to start spraying in a mosquito IPM program? Should mosquito treatments be applied over inhabited villages when there is a disease epidemic? Acknowledgments Regional Authority of Central Macedonia Development Agency of Thessaloniki Ministry of Public Health Ministry of Public Health Deployed War Fighter Research Program Greek CDC 7