David Bruce Conn. Berry College One Health Center Harvard University Museum of Comparative Zoology

Transcription

1 David Bruce Conn Berry College One Health Center Harvard University Museum of Comparative Zoology

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3 From Yang et al, Global Distribution of Outbreaks of Water Associated Infectious Diseases. PLoS/Neglected Tropical Diseases

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5 In the arena of infectious diseases, much discussion centers on whether diseases are truly emerging, or if they are re emerging. The answer depends on the individual situation. It is best to avoid thinking of pathogens or parasites as disease agents, but to recognize that all are constantly seeking only to survive and reproduce. It may be best not to think of invasive species as a discrete category, but to recognize that all organisms constantly seek to colonize and exploit any available and suitable habitat.

6 Biological invasions may occur as a result of: novel access to a new environment. adaptation to new environmental conditions by the colonizing organism. change of environmental conditions that make an environment conducive to colonization by an organisms that previously was unable to live and reproduce there.

7 Pathogens and Parasites Arthropod vectors Molluscan intermediate hosts Vertebrate hosts Intermediate Definitive

8 Vibrio cholerae From UNEP

9 Modified map on right from UCLA, showing movement from potential Nepal source.

10 West Nile Virus Dengue Yellow Fever Virus Chikungunya Fever Virus Malaria sporozoan protists Filariasis and dirofilariasis nematodes AND MANY, MANY MORE.

11 1912: Malaria eliminated from Havana.

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13 Aedes aegypti Aedes albopictus

14 Aedes albopictus

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19 The virus is endemic in tropical areas of Africa and Latin America, with a combined population of over 900 million people. (WHO website)

20 BUT most people don t know that outbreaks occurred in Boston in the 1600s 1800s, or that in 1793 one in every ten residents of Philadelphia, and in one of every eight residents of Memphis, Tennessee died from yellow fever. This is NOT a tropical disease.

21 Based on Vector Distribution and Historical Outbreaks Adding Aedes albopictus to the picture increases the range even further. From Reiter 2010.

22 Molluscan intermediate hosts Biomphalaria glabrata and other snails Schistosomiasis (freshwater blood fluke disease) Many other trematode diseases Arthropod intermediate hosts Various freshwater crustaceans Diphyllobothriasis and other tapeworm diseases Sparganosis (freshwater juvenile cestode disease) Other cestode and nematode diseases

23 Genomic evidence now suggests that the Biomphalaria snails that carry Schistosoma mansoni have invaded and reinvaded between Africa and South America/Caribbean over long periods. With climate changes, could they begin to invade the southern U.S. and southern Europe?

24 Fish Waterbirds Mammals The bushmeat trade

25 Mostly a parasite of fish, but a case of human infection in the Czech Republic was reported this year (Yera et al. 2013; Parasitology International

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27 Though fish have been regarded as infection sources in most areas, at least 1000 human cases in recent years were reported from China alone, with most thought to have been acquired from consumption of infected aquatic snakes, tadpoles or frogs. Sparganosis appears to be spreading, an invasive freshwater disease, not only in China, but apparently in other regions as well.

28 HealthHuman Health Animal Animal Health Ecosystem Health Human Health

29 We need highly integrated surveillance strategies to monitor human and animal hosts, vectors, and pathogens simultaneously. We need highly integrated response strategies geared to recognize and respond to the most vulnerable points at which each disease can be most quickly and efficiently attacked. We should not wait until we see dead or sick people before we act in any given case.

30 Tower with Number Sign Base Column Body Column Base Counterweight Anchor Chain Anchor St. Lawrence-Lake Lake Ontario Navigational Buoys

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