3. Diseases Carried by Mosquitoes* Eastern equine encephalitis Heartworm Japanese encephalitis Chikungunya La Crosse encephalitis Barmah Forest virus St. Louis encephalitis Kunjin virus West Nile virus Ross River fever Western equine encephalitis O'Nyong-nyong fever Dengue Fever/DHF Yellow Fever Malaria Murray Valley encephalitis virus Rift Valley Fever Venezuelan equine encephalitis Elephantiasis/Filariasis *a partial list
4.
5. West Nile Virus Most human cases occur in late summer and in autumn 1 ◦ Vector – Culex quinquefasciatus Highest Risk – the elderly Case Fatality Rate ~3 to 15% Yearly Occurrence (so far) West Nile virus was first isolated from a febrile adult woman in the West Nile District of Uganda in 1937. WNV first appeared in North America in 1999 in New York City. WNV was first detected in Georgia in 2001. other possible vectors : Culex spp Aedes albopictus Ochlerotatus spp 4. Describe the recent history of WNV in the US. 5. Describe the typical transmission cycle of WNV. 6. Name the primary vector of WNV in Georgia.
6. WNV is not the only mosquito-borne disease found in Georgia. We also have: LaCrosse Encephalitis (LAC) – small mammals Most human cases occur in July, Aug, & Sept Vector - Oc triseriatus , the treehole mosquito Highest Risk – children under 15 Case Fatality Rate ~1% St Louis Encephalitis (SLE) – birds Most human cases occur in late summer and in autumn Vector – Culex spp Highest Risk – the elderly Case Fatality Rate ~10% Eastern Equine Encephalitis (EEE) - birds Most human cases occur in late summer and in autumn Vector – Culiseta melanura ; a variety of bridge vectors Highest Risk – young children and the elderly Case Fatality Rate >50% Horse Fatality Rate 90-95% Sporadic Occurrence
7. Eastern Equine Encephalitis Eastern equine encephalitis virus (EEEV) is maintained in a cycle between Culiseta melanura mosquitoes and avian hosts in freshwater hardwood swamps. Cs. melanura is not considered to be an important vector of EEEV to humans because it feeds almost exclusively on birds. Transmission to humans requires mosquito species capable of creating a "bridge" between infected birds and uninfected mammals such as some Aedes , Coquillettidia , and Culex species 7. Understand the importance of EEE to mosquito control operators. 8. Describe the EEE transmission cycle.
9. Malaria 9. Name the most important disease transmitted by mosquitoes world-wide .
10. Malaria affected 30 percent of the population in the region when the TVA was incorporated in 1933. The Public Health Service played a vital role in the research and control operations and by 1947, the disease was essentially eliminated. The U.S. Tennessee Valley Authority (TVA) - The Integration of Malaria Control with Economic Development (1933) Mosquito breeding sites were reduced by controlling water levels and insecticide applications.
11. Dengue is a viral disease, commonly called "breakbone fever." Dengue epidemics were common in the 1800s and early 1900s in the U.S. The last major epidemic of dengue in the continental US occurred in Louisiana in 1945 with 62 confirmed cases, but authorities estimated that there were probably several hundred unapparent and/or unreported cases. In 1980, Texas recorded 23 locally acquired cases of dengue, and new cases occurred sporadically until 1999, when 18 cases were reported. Although dengue is not endemic now in most of the US, potential vectors are present in the southern US, and the virus is commonly reported in people entering the country from endemic areas of the tropics.
12. What is Yellow Fever? Initial symptoms include fever, headache, vomiting and backache. As the disease progresses, the pulse slows and weakens, and bleeding of the gums and bloody urine occur. Jaundice may also occur. Rural cycle Urban cycle Sylvatic cycle
16. Mosquito Biological Data SPECIES LARVAL HABITAT HOST PREFERENCE OVER-WINTER BITING TIME FLIGHT RANGE Aedes albopictus AC, TH Humans, Large Mammals Egg D 100 to 300 yards Aedes vexans FW, GP, IP Humans, Large Mammals Egg C, N 1 to 15 miles Anopheles quadrimaculatus FW, GP, LM, RP Large Mammals Adults C 1/2 to 1 mile Coquillettidia perturbans FS, RE, LM, DD Humans, Mammals, Birds Larvae C 1 to 5 miles Culex nigripalpus GP, FW, DD Humans, Large Mammals Adults C 1/2 to 1 mile Culex quinquefasciatus AC, SCB, GRP Birds, Humans, Mammals Adults C, N 1/4 to 1/2 mile Culex restuans WP, GRP, DD Birds, Humans, Mammals Adults C, N 1 to 2 miles Culex salinarius AC, GP, LM, FS Birds, Humans, Mammals Adults C, N 1/4 to 5 miles Culiseta melanura FS, WP Birds Larvae C, N 1/2 to 2 miles Ochlerotatus canadensis WP, DD, FS Small Mammals, birds, reptiles Egg C, D 0 to 1/4 mile Ochlerotatus japonicus AC Humans, Mammals, Birds Egg, Larvae D Ochlerotatus sollicitans SM Humans, Birds Egg C, D 5 to 100 miles Ochlerotatus taeniorhynchus SM Humans, Birds, Mammals Egg C, N, D 2 to 40 miles Ochlerotatus triseriatus TH, AC, Red Maple Humans, Mammals, Squirrels Egg C 1/2 to 1 mile
18. Mosquito Myths Can AIDS be transmitted by mosquitoes? There is no scientific evidence to suggest that this is possible. Is it impossible? It is safe to say that the involvement of blood-feeding insects and arthropods is biologically insignificant if it occurs at all. 12. Recognize that AIDS is not transmitted by mosquitoes.
19.
20.
21.
22.
23.
24.
25. 3. Describe the proper technique for using insect repellents. The 5 D’s of DISEASE PREVENTION: Dusk Avoid being outdoors when Dawn mosquitoes are most active. Dress Cover your skin with protective clothing DEET Protect bare skin with mosquito repellent. Drain Empty containers holding stagnant water in which mosquitoes breed. Credit: J.Rutherford, Monroe CHD
26.
27.
28.
29.
30.
31. Knowing what mosquito species are present and where they are breeding is essential to a well-planned mosquito control program. SURVEILLANCE
32.
33. 5. Understand the concept of larval and adult surveillance. Gravid Trap Light Trap Mosquito Surveillance
34.
35.
36. What Kind of Trap Should You Use? depends on your need and your budget
46. 9. Name the most common type of adulticide application conducted today. Treatment of adult mosquitoes (adulticiding) is the most visible practice exercised by mosquito control operations. This option is usually reserved for managing mosquito populations that have reached the adult stage in spite of efforts to intervene in the larval stage or when such treatments have not, or cannot, be conducted. Adulticides are often applied as ultra‑low‑volume (ULV) sprays in which small amounts (3 fluid ounces or less per acre) of insecticide are dispersed either by truck-mounted equipment or from fixed‑wing or rotary aircraft.
47.
48.
49.
50. The risk of developing insecticide resistance in insect populations can be minimized by the use of Integrated Mosquito Management techniques. These practices try to reduce the need for insecticide applications. In addition, it is prudent to rotate the type of insecticide, active ingredient and corresponding mode of action of the insecticides used against an insect population. While this may necessitate the use of a more expensive product for some applications, the long term benefits of preserving susceptibility far outweigh any short term costs. There are a limited number of insecticides registered for mosquito control.