Highlights of Medical Entomology

Transcription

1 Highlights of Medical Entomology 16 November :15 pm Donald A. Yee University of Southern Mississippi Hattiesburg, MS Copy of this talk?

2 Criteria for selection Journals, Databases, News, Colleagues Focal Journals Am J Trop Med, Emerg Infect Dis, J Am Mosq Control Assoc, J Med Entomol, J Vector Ecol, Malaria J, Med Vet Entomol, PLoS Negl Trop Dis, Vector Borne Zoon Dis Other Journals Am Nat, Annu Rev Entomol, Ecology, Ecol Appl, Ecol Entomol, Evolution, Ecol Lett, Ecol Monogr, Genetics, J Anim Ecol, Nature, PNAS, Science, Virus ~ 300 articles (31 selected, 3 books)

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4 Themes Old Threats Emerging Threats New Enemies Climate change Innovations and New Approaches Reviews & Books

5 s Old Threats

6 s Examined data from By 2004 states had well-developed programs By 2012 dramatic decrease in funds and programs Challenges to future disease outbreaks

7 data from Simulation method for prediction of high incidence of Lyme based on current incidence s Expansion was predicted but core areas were maintained NS has highest incidence in Canada 329 cases since 2002 Spread is likely, but past endemic regions are of biggest concern

8 Mechanism s for rapid expansion of blacklegged tick is unknown Migration/colonization? Population growth? Bayesian analysis and population genetics approach New tick populations likely from colonization events from south to north New genetic variants may have arose due to novel selective environments

9 s Emerging Threats

10 No reported cases in Japan in 70 years In late 2014, 160 autochthonous cases in Tokyo dengue serotype 1 Aedes aegypti rare in this area Ae. albopictus common in Tokyo Mosquitoes challenged with R. felis (fleas) was detected up to 15 d Bites of infected mosquitoes caused transient rickettsemias in mice Help explain many reports of fever unknown origin

11 1,967 Mb (largest sequence of mosquitoes to date) Expansion of gene families involved in resistance, diapause, sex determination, immunity, olfaction contribute to larger genome size Portions of integrated falvivirus-like genome support shared evolutionary history Large genome may assist in adaptability and success

12 Historical examination of history of diseases and terminology in the Americas dengue (Spanish) and chikungunya (Makonde of Africa) have alternated for each other! s Not until 1963 epidemic in India that led to the clinical differences between syndromes; gave us the modern use of the names

13 s New Enemies

14 Captured in Indian River, FL; formally only from Jamaica, Dominican Republish, Haiti, Bahamas Culex (Culex) interrogator, a mosquito species new to Florida Florida Mosquito Control Association meeting, 2014 George s O Meara, FMEL Summer 2014, Indian River County, FL. > 3000 egg rafts of which 9 rafts were laid by Cx. interrogator, prior restricted to southern Texas and other states bordering Mexico Third Culex in the last decade(cx. declarator 2002, Cx. coronator 2005) Niche models suggest widespread suitability Occurrence in suboptimal areas may be useful for control

15 Previous transmission records via contact with rodent excreta Virus has been found in lone star ticks in Florida (11.2% those tested) Reservoir host remains unidentified First discovered in 2009 in Missouri, Oklahoma, Tennessee Wildlife serology suggests 13 affected states (MO, TN previous records)

16 s Climate Change

17 Occurrence of dengue and chikungunya in Nepal is examined Presence of Aedes aegypti in 2009, dengue outbreak in 2010 in lower elevations Ae. aegypti and Ae. albopictus (2 ) occur up to 2100 m Climate (rainfall, temperature, humidity) predictors of vectors Pronounced warming likely led to expansion of vector

18 Examined climate conditions in the range prior to expansion Use thermal and aridity-humidity indices Historic range included pre-humid rain forests to semiarid steppe Hypothesize that it originated under monsoon climate with distinct dry seasons, with wet summers

19 35 year study on questing Ixodes ricinus in Russia Increase in populations across Europe Dramatic increase in over the last 21 years in abundance Small mammal populations were constant over this time, large mammals has small fluctuations Climate change and anthropogenic changes driver of tick abundance increase Temperature effects on survival (+), arable lands abandoned and produced more forest (+)

20 Examined various future climate scenarios for Anopheles distribution and Plasmodium falciparum in South America By 2070, regardless of climate combinations expanded range of Anopheles and P. falciparum spread to 35-45% of continent Shift away from An. darlingi and toward Albitarsis complex based on climate Vector Borne Zoonotic Dis Mar;15(3): doi: /vbz Examination of validation methods for models of climate change on arthropod vectors of disease

21 Innovations and New Approaches s

22 Challenge of arboviruses: labile in nature, low prevalence, labor costs for ID, equipment and expertise needed to detect Adding FTA cards (honey-baited nucleic acid preservation card) to CO 2 trap Mosquitoes fed on the FTA card and card analyzed for virus Detection of three types of viruses (Ross River, Barmah Forest, Stratford) Improvement for surveillance without significant additional costs

23 e-nets and e-cloth are used for capture of Tsetse fly adults Compared flight vs. alight cloth designs as well as net size, color, pulse frequency Recommendations for various applications

24 Review of natural infections of viruses in mosquitoes How do these natural viruses interact with arboviruses, affect transmission Outlines a) how detected, b) viral maintenance, c) viral diversity and evolution, d) effects on vector competence, e) novel applications for control s Examined how these species would be affected by infection by both viruses Simultaneous, separately, or inverse order oral infections offered Simultaneous dissemination for all Co-transmission for CHIKV and DENV-2 at low rates for sequential but not simultaneous infection

25 Examined Plasmodium relictum and Culex pipiens infection across ages (7 d, 17 d) and prior blood feeding (yes, no) Lower infection with older animals with no prior blood meal Reversed when older adults were exposed to a prior blood meal Structural and functional alternations in physiology with age Reversal may decrease age effect in nature

26 Metarhizium anisopliae, fungal pathogen for control of Aedes aegypti Auto-dissemination from infected males to females Infected males had lower mortality and longer development but equal insemination compared to uninfected males 5 th mating still resulted in 50% mortality of females Potential biocontrol of adults

27 Know occurrences of species from Data (geo-positioned occurrence records) include 19,930 Ae. aegypti, 22,137 Ae. albopictus Data sets are open to use in R

28 s Reviews & Books

29 Current knowledge of molecular mechanisms, genes, gene interaction, and gene regulation of resistance s Examine the importance of the modern human life style and arbovirus emergence Based on this, control strategies to reduce their effect

30 Examines the lack of large outbreaks of WNV in Florida, including environmental factors affecting the vector, Culex nigripalpus Overview of mosquito cues for oviposition from larval food, larvae, predators, synthetic compounds

31 Review of the effects of biodiversity on infectious disease risk Provide a predictive framework for biodiversity effects s Specifically examine host richness, trophic structure, functional diversity, and symbiont composition, across spatial and temporal scales

32 A. Townsend Peterson Mapping Disease Transmission Risk Johns Hopkins University Press ISBN 13: Introduces ecologic niche models as predictors of disease transmission risk Part I describes distributional ecology Part II explore data necessary to develop ecologic models rather than arbitrarily complex black box models Part III provides information for how not to collect data Part IV for calibrating, processing, and evaluating models and the production of risk maps Merrill Singer Anthropology of Infectious Disease Left Coast Press ISBN-13: Examine how pathogens are intertwined with human social worlds Case studies including malaria and Lyme disease Biosocial/biocultural approach to the understanding of infectious disease Emphasis on interactions among biologic, political, economic, sociocultural, and ecologic factors and how these factors affect the emergence, prevention, treatment, distribution, cultural experiences, and global impact of pathogens.

33 Zach Adelman Genetic Control of Malaria and Dengue Academic Press ISBN Coverage of vectorial capacity, critical to understanding vector-borne disease transmission Summary of the concepts of both population suppression and population replacement Coverage of ethical and ecological ramifications of genetics-based control strategies