Test four Flashcards

1
Q

Plasmodium

A

Disease organism

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2
Q

Family Culicidae

A

Mosquitoes
Great habitat diversity
Approximately 40 million years older than humans
Pests as well as vectors of pathogens causing human and animal disease

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3
Q

Subfamily

A
  1. Anophelinae - anopheles

2. Culicinae - aedes, culex, Haemagogus, Mansonia, Ochlerotatus and all other genera

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4
Q

Mosquito Characteristics

A

Bloodfeeding - only females take blood
Males and females feed on plant sugars
Larval biology - 4 stages (instars), aquatic, spiracle for breathing, filter-feeders, some cannibalistic, variable habitats

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5
Q

Malaria

A

Caused by a protozoan

Curable if promptly diagnosed and treated

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6
Q

Worse type of malaria

A

Plasmodium falciparum

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7
Q

Life cycle of Malaria

A
  1. A mosquito injects sporozoites into the blood stream
  2. They invade liver cells and transform into merozoites (this process is called exoerythrocytic schizogony. There are no disease symptoms during this stage
  3. Each cell ruptures, releasing tens of thousands of merozoites. Penetrating a red blood cell, a merozoite multiplies. This is called the erythrocytic stage (this is when clinical features develop)
  4. Each red cell bursts and releases more merozoites
  5. They infect more red blood cells and multiply again
  6. Some merozoites develop into male and female forms called qametocytes
  7. Feeding on a person with malaria a mosquito ingests the gametocytes
  8. They reproduce and develop into oocysts, which rupture and release sporozoites
  9. The sporozoites migrate from the mosquito’s gut to the salivary glands, ready to be injected into a human host
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8
Q

Erythrocytic Stage

A

intracellular parasite undergoes trophic phase
young trophozoite called ‘ring form’
ingests host hemoglobin

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9
Q

Exoerythrocytic Schizogony

A
hepatocyte invasion
asexual replication
6-15 days
1000-10,000 merozoites
no overt pathology
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10
Q

Sporogony

A
occurs in mosquito (9-21 d)
fusion of micro- and macrogametes 
zygote  ookinete (~24 hr)
ookinete transverses gut epithelium ('trans-invasion')
ookinete --> oocyst
asexual replication --> sporozoites
sporozoites released
sporozoites migrate through hemocoel
sporozoites 'invade' salivary glands
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11
Q

Symptoms of Encephalitis

A
Fever
Headache
Behavioral changes
Altered level of consciousness
Seizures
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12
Q

Encephalitis is

A

Acute inflammatory process affecting the brain

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13
Q

Encephalitis caused by

A

viruses or arboviruses

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14
Q

Arboviruses are

A

arthropod born viruses

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15
Q

Major arboviruses that cause encephalitis

A

Flaviviridae
Togaviridae
Bunyaviridae

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16
Q

Flaviviridae

A

West nile
st. louis encephalitis
Powassan virus

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17
Q

Togaviridae

A

E and W equine

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18
Q

Bunyaviridae

A

La Crosse

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19
Q

West Nile Virus

A

Primary host – wild birds

Principal arthropod vector – mosquitoes

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20
Q

1999 NY West Nile Outbreak

A

Crows dying in Queens, late summer
27 Deaths among captive birds
59 Human cases needing hospitalization, 7 deaths

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21
Q

Spread of West Nile in the US: 2000

A

spread throughout New England and Mid-Atlantic regions.

18 new human cases reported

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22
Q

Spread of West Nile in the US: 2001

A

spread throughout the entire eastern half of the US

64 cases reported, with NY, FL and NJ accounting for 60%

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23
Q

Spread of West Nile in the US: 2002

A

spread westward across Great Plains into Western US. Reached California by Labor Day.
By end of 2002 cumulative human cases > 3900, with > 250 deaths

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24
Q

Spread of the West Nile in the US: 2003

A

US, Canada, Mexico

9,858 cases reported to CDC, including 262 deaths in 45 states and D.C.

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25
Q

According to the CDC: What % of WN cases are fatal? sever forms kill?

A

Less than 1%

3-15%

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26
Q

St. Louis Encephalitis

A

Most common mosquito-transmitted human pathogen in the US

First isolated in 1933 in St. Louis, MO

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27
Q

St. Louis Encephalitis Case fatality ratio

A

5-15%

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28
Q

Easter Equine Encephalitis

A

Caused by a virus transmitted to humans and horses by the bite of an infected mosquito.
Average of 4 cases per year
Human cases occur relatively infrequently, largely because the primary transmission cycle takes place in swamp areas where populations tend to be limited.

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29
Q

E. Equine: 1831

A

First recognized as a disease in horses.

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30
Q

E. Equine: 1947

A

largest recorded outbreak in Louisiana and Texas. 13,344 cases and 11,722 horse deaths

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31
Q

W. Equine

A

Mosquito-borne
639 confirmed cases in the US since 1964
Important cause of encephalitis in horses and humans in North America, mainly in the Western parts of the US and Canada

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32
Q

W. Equine: 1912

A

25,000 horses died in Central Plains of US

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33
Q

La Crosse

A

On average 75 cases per year reported to the CDC
Most cases occur in children under 16 years old
Zoonotic pathogen that cycles between the daytime biting treehole mosquito, and vertebrate amplifier hosts (chipmunk, tree squirrel) in deciduous forest habitats

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34
Q

CDC’s “Three Ways to Reduce your West Nile Virus Risk”

A

Avoid mosquito bites
Mosquito-proof your home
Help your community

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35
Q

Yellow Fever

A

Caused by yellow fever virus (Flavivirus)

Transmitted predominantly by Aedes mosquitoes

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36
Q

Yellow Fever: Genus/Family

A

Flavivirus fibricus, Group B Arbovirus

Toga virus

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37
Q

YF Virus size? Consists of?

A

35-40 nm, single strand of RNA virus

38
Q

Natural host of YF in Forest areas:

A

Primates non human

39
Q

Vectors of YF in Forest areas:Africa

A

Aeded africanus

40
Q

Vectors of YF in forest areas: S. America

A

Haemagogus

41
Q

Vectors of YF in urban areas: African/S. America

A

Aedes aegypti

42
Q

Rold of humans in YF Transmission

A

Incubation period of 2-6 days
Human become viremic; capable of infecting mosquitoes
The extrinsic incubation period in Ae. aegypti is 9–12 days

43
Q

Clinical features of yellow fever: acute phase lasting? symptoms?

A
4-5 days
a sudden onset of fever
headache or backache
muscle pain
nausea
Vomiting
red eyes
44
Q

YF can be strongly suspected when what is present?

A

Faget’s sign

45
Q

Faget’s sign:

A

The simultaneous occurrence of a high fever with a slowed heart rate.

46
Q

YF Toxic Phase presents with:

A
jaundice
Bleeding from the gums, nose or in the stool
vomiting blood
diarrhea
slow pulse in relation to fever
47
Q

Dengue Fever spread by

A

mosquito

48
Q

Dengue Fever: AKA, define

A

Breakbone fever

is an acute communicable disease caused by virus.

49
Q

Dengue Fever: Infectious Agen

A

Dengue viruses (another RNA virus in the Flavivirus family)

50
Q

DF highest in what area

A

Tropical and subtropical regions

51
Q

More sever form of Dengue is:

A

Dengue Hemorrhagic fever

52
Q

Symptoms of Dengue Hemorrhagic Fever

A

Severe and continuous pain in abdomen
Bleeding from the nose, mouth and gums or skin bruising
frequent vomiting with or without blood
stools, like coal tar
After several days the patient becomes irritable, restless, and sweaty

53
Q

Three main forms of leishmaniasis

A

Cutaneous
Visceral
Mucocutaneous

54
Q

Cutaneous

A

involving the skin at the site of a sandfly bite

55
Q

Visceral

A

involving liver, spleen, and bone marrow

56
Q

Mucocutaneous

A

involving mucous membranes of the mouth and nose after spread from a nearby cutaneous lesion (very rare)

57
Q

Leishmania donovani

A

VISCERAL LEISHMANIASIS: involving endothelial tissue liver, spleen, and bone marrow.

58
Q

Leishmania tropica (CL)

A

OLD WORLD CUTANEOUS LEISHMANIASIS: involving epithelial cells the skin at the site of a sand fly bite.

59
Q

Leishmania brazilliensis (MCL)

A

NEW WORLD MUCOCUTANEOUS LEISHMANIASIS: involving mucous membranes of the mouth and nose after spread from a nearby cutaneous lesion.

60
Q

Transmission of Leishmaniasis

A

By sand flies.
Artificial transmission of leishmania via the sharing of contaminated syringes and needles, from one intravenous drug user to another.
Rarely, Leishmaniasis is spread from a pregnant woman to her baby.
Blood transfusion is another possible mechanism of transmission.

61
Q

Cutaneous Leishmaniasis: forms?

A

Cutaneous forms of the disease normally produce skin ulcers on the exposed parts of the body such as the face, arms and legs. The disease can produce a large number of lesions

62
Q

Rocky mountain spotted fever

A

The most virulent of the “spotted fever group” of rickettsiae
First described in Idaho in the late 19th Century
Causative agent named Rickettsia rickettsii
The tick is the vector and main reservoir

63
Q

Which tick is main vector of RMSF?

A

Dermacentor variabilis – American dog tick

64
Q

RMSF: Causative agent?

A

Rickettsia rickettsii

65
Q

RMSF: Clinical Manifestations

A

Incubation period of 2 to 14 days
Starts with fever, myalgia, headache (usually severe)
High temp- >1020 F in most
Nausea, vomiting, abdominal pain, diarrhea

66
Q

Basic categories/examples of cultural techniques

A

Cropping tactics
Harvest Tactics
Sanitation

67
Q

Benefits of cultural controls

A

Often easily incorporated into the production system
predictable level of control, even if partial
Fast acting
As a group, relatively sustainable

68
Q

Disadvantages of Cultural Controls

A

Some are not environmentally benign (e.g. conventional tillage, residue burning)
May alter crop value or gross income (planting date, harvesting, spacing)
Some are labor/energy intensive (pruning, tillage)
Widespread adoption may be low
Many conflicts

69
Q

Field Preparation & Planting

A

Plant & row spacing
Planting date (early vs late)
Planting method (depth, insertion method)
Mulches – organic & synthetic

70
Q

Cropping Tactics

A

Trap/Barrier Crops
Intercropping
Cultivar mixtures

71
Q

Trap/Barrier Crops

A

Trap crops are destroyed with the pest
planting plants that attract pests and then harvest or spray trap crop
Planting geraniums attracts Japanese beetles, which are poisoned by the geraniums
Barrier crops are on field perimeter

72
Q

Intercropping

A

Two or more useful crops

73
Q

Cultivar mixtures

A

Different cultivars may have to be planted in different fields to create a “cultivar patchwork”.

74
Q

Water Management

A

flooding may destroy soil pests

light sprinkling at specific times may decrease ovipositioning of pests

75
Q

Crop Rotation

A

Intercropping in time
Especially effective against soil-based pests: Weeds, soil-borne pathogens, root-feeding insects
For weeds:
Changes weed complex
Not stand alone weed mgmt, instead used to facilitate weed mgmt

76
Q

Harvest Tactics

A

Harvest timing (early vs late) – may use early/late varieties.
Crop matures before pests build up
Harvesting operation itself causes extensive mortality.

77
Q

Harvest method

A

Partial Harvesting – Prevents movement to high value crops
Maintains young age structure
Concentrates natural enemies (usually more mobile)

78
Q

Sanitation

A

Residue removal
Burning
Pruning (Removing Part of a Plant)
Infected/Infested host tissue
Foliage that provides pest access
Alters canopy microclimate
Removing other resources

79
Q

Varroa Mites – cultural control

A

Apiary site location
Comb culling
Requeening w/ resistant (tolerant) stock

80
Q

Varroa Mites – physical control

A

Screened bottom boards (season long)

Heat (104-110◦F for 4 hrs)

81
Q

Cultural control in the greenhouse

A

Inspect new plants thoroughly, reject or discard badly infested ones.
Use fine mesh screening on doors, screens, and ventilators
Use clean or sterile soils or media
Eliminate pools of standing water and any insect breeding debris
Avoid over-watering and promote good ventilation

82
Q

Thrips IPM

A

Sanitation
Remove weeds that act as a thrips refuge.
Remove and destroy crop residues after harvest.
Remove all soil debris from greenhouse.
Screen windows, vents, and fans.
Pasteurize soil to kill immature thrips

83
Q

Which caused by virus?

A

Yellow fever

Dengue fever

84
Q

Which caused by bacteria?

A

Encephalitis

RMSF

85
Q

Caused by Protozoa

A

Leishmaniasis

86
Q

Mosquito vectors for?

A
Yellow fever
Dengue fever
Encephalitis
W/E equine
La crosse
Malaria
87
Q

Ticks vector for?

A

RMSF
Tularemia
Lyme disease

88
Q

Sand flies vector for?

A

Leishmaniasis

89
Q

Regulatory control

A

Prevention of pests from entering the country (APHIS)
Rationale
some pests can be excluded by quarantines
cheaper to try and exclude pests than trying to control them
Quarantines only useful for
new pests

90
Q

Mechanical transmission.

A
  • Facultative
  • On mouth parts only (usually)
  • Vector must be constantly re-infected
  • immediate infectivity
91
Q

Propagative transmission.

A
  • Obligatory
  • Enter insect gut
  • Latent period
  • Disease titer increases