arboviruses Flashcards
(21 cards)
arboviruses
any of a group of viruses that are transmitted by mosquitoes, ticks, or other arthropods. They include encephalitis, dengue, and yellow fever.
arboviruses
RNA \+ss flavi family( same as HCV) cos has membrane replicates usually in mosquito salivary gland, then is available to be transmitted to new host
arboviruses
Yellow Fever virus
West Nile virus
Dengue Virus
Zika
arboviruses can cause
-Encephalitis
• Febrile diseases
• Occasionally hemorrhagic fevers
prevention and facts
Prevention depends on surveillance
Physicians, veterinarians
Curbing mosquito habitats is important
Remove standing water
80-90% of infections are asymptomatic.
Less than 1% of people who become
infected with West Nile virus will develop
severe illness.
arboviruses cycles
1. syllabic cycle examples West nile, Zika animalarthropod---->>>>>>human (human not a part of the cycle) 2. urban examples Dangue, Yellow fever, Zika humanarthropod
major reservoir
Infects many kinds of birds and mammals.
Birds are the major vertebrate reservoir.
west nile virus
incubation period for WNV infection
is about 2 to 14 days
Serious Symptoms in a Few People. The severe symptoms can include high fever, headache,
neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness,
vision loss, numbness and paralysis. These symptoms may last several weeks, and
neurological effects may be permanent.
▪ Milder Symptoms in Some People. Up to 20 percent of the people who become
infected will display symptoms which can include fever, headache, and body aches,
nausea, vomiting, and sometimes swollen lymph glands or a skin rash on the chest,
stomach and back.
Dengue
Mostly in the tropics. Spread by aedes mosquitos. 4 serotypes - they used to be localized, now spread. Fever, headache, myalgia, bone ache (breakbone fever).
Immunopathological - reinfection with a second serotype
results in antibodies from the first infection making the second
infection worse - ADE: Antibody Dependent Enhancement of
infectivity.
Humans are the only vertebrate reservoir besides monkeys,
zika
Zika was first discovered in monkeys in Uganda in 1947.
types of mosquitos for zika dengue
Aedes aegypti mosquitoes
Aedes albopictus mosquitoes.
zika symptoms
Fever, rash, joint pain, red eyes, and muscle aches.
Guillain-Barré syndrome.
Can infect skin cells, dendritic cells, placental cells, brain glial cells, neurons, neural
progenitor cells and probably many more. It uses many cell receptors.
Shows up in a person’s bloodstream about one week after infection.
First insect-borne disease with a proven link to serious birth defects.
First arbovirus to be sexually transmitted.
zika reservoir
The virus has been isolated in monkeys, and antibodies have been detected in domestic
sheep, goats, horses, cows, ducks, rodents, bats, orangutans, and water buffalo.
Congenital Zika syndrome
including severe microcephaly, decreased brain tissue,
damage to the eye, clubfoot, and muscle development
problems that lead to restricted movement soon after a
baby is born.
first trimester is
the most dangerous, but a Zika infection in the mother could harm the fetus at any point during pregnancy.
ebola
RNA -ss ebola, Marburg Filo family cause hemorrhagic fever helical membrane
Ebola Virus
rapid accumula@on gene@c varia@on
• First discovered in 1976 near the Ebola River in the Democra@c Republic of Congo
• Sporadic outbreaks in Africa
• Bats are the most likely reservoir (zoonosis)
2014 outbreak Ebola
largest
effected countries: guinea, Sierra Leone, Liberia
incubation period and symptoms for ebola
2-21 days, ave 8-10 days
Symptoms Fever Severe headache Muscle pain Weakness Fa'gue Diarrhea Vomi'ng Abdominal pain Hemorrhage (Bleeding or Bruising)
Death
ebola entry
- through mucous membranes or parenterally, e.g. breaks in the skin.
- has to be a ——-DIRECT CONTACT with blood or body fluids of a person sick with
Ebola
—-Objects (needles and syringes) contaminated with virus
Infected animals
- no air contamination
mechanism:
Ebola virus infects many cell types, including monocytes,
macrophages, dendri’c cells, endothelial cells, fibroblasts,
hepatocytes, adrenal cor’cal cells and epithelial cells.
virus migrates: inital infection site –»lymph nodes –» liver, spleen and adrenal
gland.
Ebola virus appears to trigger a release of pro-inflammatory cytokines
with subsequent vascular leak and impairment of clottig ultimately
resulting in multi-organ failure and shock.
ebola vaccine
rVSV-ZEBOV
it is a recombinant, replication-competent vaccine. It consists of a vesicular
stomatitis virus (VSV), which has been genetically engineered to express a glycoprotein from
the Zaire ebolavirus so as to provoke a neutralizing immune response to the Ebola virus.
It is 70-100% effective.
post exposure vaccine
NBP134 pan-ebolavirus = antibody cockteil
