Dengue/YF & Zika/West Nile

Which of the following are the correct family and genus of Dengue, Yellow fever, Zika and West Nile virus? A) Flaviviridae, Flavivirus B) Bunyaviridae, Hantavirus C) Adenoviridae, Flavivirus D) Flaviviridae, Enterovirus

A) Flaviviridae, Flavivirus

Which of the following is considered the history of yellow fever? Select all that apply. A. The term was first used in Barbados. B. Introduced from Africa. C. First isolated in West Nile District, Uganda. D. Had its last outbreak in U.S. E. Controlled in Cuba and Panama.

A. The term was first used in Barbados. B. Introduced from Africa. D. Had its last outbreak in U.S. E. Controlled in Cuba and Panama.

What is the principal urban vector for dengue virus? A. Anopheles B. Aedes C. Culex D. Culiseta

Aedes

All of the following are Modalities of Transmission of Zika Virus EXCEPT FOR: A) Serum Transfusion B) Sexual Transmission C) Airborne Transmission D) Vector Transmission

Airborne Transmission

Which of the following is NOT an effective method of diagnosing dengue? A. Reverse transcriptase PCR B. Hybridization probes C. Flow cytometry D. Immunohistochemistry E. All of the above methods are useful in dengue diagnosis

All of the above methods are useful in dengue diagnosis

In class, we went over how the possible routes of transmission for the virus include enzootic/epizootic vectors of transmission. What is the difference between the two? Further, Why is it important to know this?

An enzootic disease is one in which it affects a certain animal population, however, only affects a small amount of animals at one time. A Epizootic vector is one in which there is a sharp increase of the number of new cases of a disease in a specific population. This is the difference between the two. It is important to know this, because by knowing how virology affects other species, humans may prevent future endemics from arising through the spread of vector borne zoonotic diseases. With extensive knowledge, and plan of action, humans will be more prepared to fight for the safety of the human race through studying different virus' virologies in populations of other species, how they affect human vectors, and even how they may directly affect humans.

Jojo is a historian who is visiting Uganda. From Prior knowledge, he knows that the Zika Virus was first originated in Uganda in 1947. He is stressed, and approaches you knowing that you are an aspiring infectious disease specialist. What advise would you MOST LIKELY tell him? A. Get the Vaccine for Zika B. Urge him to carry pesticides and to use them frequently outside to kill mosquitoes around his premises. C. Use DEET-based repellents before going out D. Cover all areas of skin to avoid being bit at all cost

Ans: C. There is no current vaccine for Zika. In addition, it would not be the best use to carry around pesticide, as spraying pesticides around would contaminate the ecosystem, messing with it's dynamic equilibrium. To cover all areas of skin at all times would be unpractical. Therefore, the best answer is C.

True or False. One of the modalities of transmission of Zika Virus is sexual transmission.

Answer is True. The modalities of transmission of Zika Virus all includes: mosquito bites, sexual transmission, and blood transfusion.

Which of the following is not contained in mosquito saliva? A(n)... A)Virus B)Anticoagulant C)Antihistamine D)Painkiller E)All of the above are within mosquito saliva

Antihistamine

True or false, regarding public health infrastructure, there has been a emphasis on larval source reduction over emergency epidemic response.

False

Which modality of Zika virus transmission is most frequent?

Mosquito bites

List the three modalities of Transmission of Zika Virus

Mosquito bites, Sexual Transmission, Blood Transfusion

According to the article, why are the majority of imported dengue cases never reported in the United States?

Most physicians in the United States have a low index of suspicion for dengue, which is often not included in the differential diagnosis of acute febrile illness, even if the patient recently returned from a tropical country.

What kind of cell is DNA containing the Zika gene injected into to stimulate the body into producing virus-like particles? a. Muscle Cells b. Blood Cells c. Stem Cells d. Bone Cells

Muscle Cells

Why did the West Nile virus spread so quickly across the United States?

The West Nile virus (WNV) can infect both birds in addition to mosquitos, making birds an animal reservoir. This means that infected migratory birds that traverse rapidly across the nation aid in spreading the disease to humans much more efficiently. In addition, the mosquito species primarily responsible for the spread of WNV, Culex pipiens, undergo diapause, allowing them to survive the winter and continue to infect colder climates. This means that vertical transmission occurs and the disease continues to spread, even throughout winter.

True or False. Immunity to West Nile Virus has been observed in some populations

True, in some African populations the prevalence of background immunity of WNV is 50% in children and 90% in adults.

True or False, Can an individual be infected by 4 dengue serotypes during their lifetime.?

True, infected individuals only receive immunity for the specific serotype they were infected by.

What is the current best personal defense against West Nile Virus or Zika? A. Get vaccinated against the virus B. Use DEET based repellants before you go outside in the morning or evening C. Cover your sleeping area with a mosquito or insect net before sleeping D. Avoid contact with someone who is exhibiting symptoms of the virus.

Use DEET based repellants before you go outside in the morning or evening

Animal Reservoirs play a major role in the spread of viruses. Which of these viruses has a different animal reservoir than the others? A)Yellow Fever B)West Nile C)Dengue D)Zika

West Nile

Fill in the blanks: Yellow fever is a hemorrhagic virus belonging to the genus ____________. It is an ______ (RNA/DNA) virus whose genome encodes for _________ structural and __________ nonstructural proteins. The insect responsible for transmitting Yellow fever between humans is the ____________________________. These vectors require _______________ (length of time) between getting and transmitting the virus, also called the _____________________________________.

Yellow fever is a hemorrhagic virus belonging to the genus (Flavivirus). It is an (RNA) virus whose genome encodes for (three) structural and (seven) nonstructural proteins. The insect responsible for transmitting Yellow fever between humans is the (Aedes aegypti mosquito). These vectors require (1-2 weeks) between getting and transmitting the virus, also called the (extrinsic incubation period.)

Where did scientists first discover the Zika virus?

Zika forest, Uganda

(SELECT ALL THAT APPLY) The hybridization probe method is a diagnosing tool created in recent years for the Dengue virus. It involves utilizing serotype-specific probes generated by researchers to diagnose someone. Why is this method not widely utilized in diagnostic laboratories? a) Data shows the scientists that this test is less sensitive than other diagnostic methods such as RT-PCR, making it less reliable. b) The test is affected by inhibitory substances such as neutralizing antibodies. c) The test simply takes too long to return results. By the time results have been generated and reproduced, the disease has already advanced in a patient. d) This test demands more technical expertise and training from its performer than most tests, such as PCR. e) The test requires fresh human samples and cannot be performed on preserved samples, such as fixed autopsy tissue. f) The test is too complex and costly to have practical use in diagnostic laboratories. b) The test is affected by inhibitory substances such as neutralizing antibodies. c) The test simply takes too long to return results. By the time results have been generated and reproduced, the disease has already advanced in a patient. d) This test demands more technical expertise and training from its performer than most tests, such as PCR. e) The test requires fresh human samples and cannot be performed on preserved samples, such as fixed autopsy tissue. f) The test is too complex and costly to have practical use in diagnostic laboratories.

a) Data shows the scientists that this test is less sensitive than other diagnostic methods such as RT-PCR, making it less reliable. & d) This test demands more technical expertise and training from its performer than most tests, such as PCR

The case fatality percent found in Yellow Fever is found to be ____, while the case fatality percent in Dengue is ____. a. 20%, 5% b. 15%, 10% c. 50%, 50% d. 5%, 20%

a. 20%, 5%

List the 2 main measures that were used to control the cases of yellow fever in the 20th century. (short answer)

1) A yellow fever vaccine was developed (especially useful in Africa) 2) Aedes aegypti eradication program was implemented in the Americas]

What are the 5 Major factors of Dengue Virus spread?

1) Exponential Population Growth 2) Increase in Urbanization and movement of people into population centers 3) Lack of effective Mosquito control (that doesn't have ecological repercussions) 4) Air Travel (and volume of travel) 5) Decay and lack of public health infrastructure in high-risk countries

What is the case fatality of Dengue hemorrhagic fever? A: 3% B: 0.01% C: 5% D: 10%

5%

In what year was the Yellow Fever vaccine developed? A. 1906 B. 1949 C. 1899 D. 1936

1936

How many Structural and non-structural proteins are present in flavivirus? a) 4 structural, 6 non structural b) 3 structural, 7 non structural c)7 structural, 3 non structural d) 6 structural, 4 non structural

3 structural, 7 non structural

There are ___ dengue virus serotypes. a) 3 b) 7 c) 4 d) 5

4

Which of the following is the correct difference between the two Zika Virus vectors, Aedes aegypti and Aedes albopictus? (Select all that apply) A. Aedes aegypti has a singular line on its torso while Aedes albopictus has a lyre-shaped torso. B. According to the estimated range in the United States in 2016, Aedes aegypti is not found in Massachusetts, but Aedes albopictus is found in Massachusetts. C. Aedes aegypti is a sneaky biter, while Aedes albopictus is an aggressive biter. D. Aedes albopictus is usually found in urban areas, while Aedes aegypti is usually found in arboreal vegetation.

B. According to the estimated range in the United States in 2016, Aedes aegypti is not found in Massachusetts, but Aedes albopictus is found in Massachusetts. C. Aedes aegypti is a sneaky biter, while Aedes albopictus is an aggressive biter.

Why did Zika not widely spread in the U.S. similarly to other countries? A. The U.S. has a vaccine for Zika. B. Monkeys were the original reservoirs and are not common in nature in the U.S. C. WHO has designated the Zika virus a public health emergency which has led to funding and manpower being allocated to fight the pathogen. D. The U.S. has DEET in their water supply

B. Monkeys were the original reservoirs and are not common in nature in the U.S.

Which of the following is not a RNA virus of the genus Flavivirus? A. Westnile Virus B. Smallpox Virus C. Zika Virus D. Yellow Fever

B. Smallpox Virus

Which virus is able to be acquired in the laboratory setting via airborne transmission or percutaneous inoculation? A. Dengue B. West Nile Virus C. Zika Virus D. Yellow Fever

B. West Nile Virus

Viruses such as the West Nile Virus are transmitted through a vector such as a mosquito, however these vectors are not the natural reservoir for the viruses, where they can amplify and mutate. What is the natural reservoir for the West Nile Virus? A. Bat B. Cattle C. Buffalo D. Bird

Bird

Which of the following serves as the animal reservoir for the West Nile Virus? A. Primates B. Dogs C. Birds D. Fish

Birds

Aedes aegypti is the scientific name of the mosquito that is most commonly associated with the spread of Dengue and Yellow Fever, in that it is the principle urban vector of these diseases; which of the following is NOT one of the characteristics of these mosquitos? A. Breeding in domestic water supplies B. Day biting C. Black and yellow striped bodies D. Humans are preferred source of blood meal

Black and yellow striped bodies

The pesticide DTT affects: a) Calcium Synthesis b) Electron Transport Chain c) Vitamin B Synthesis d) Gluconeogenesis

Calcium Synthesis

Which of the following statements are accurate? A) The best defense that currently exists on a personal level from WNV and ZIKA are vaccinations combined with use of DEET-based repellents B) WNV and ZIKA can be controlled on a population level through a variety of specific approved methods C) There are currently no specific treatments for WNV and ZIKA D) DEET-based repellents are ineffective in repelling against WNV or ZIKA infected mosquitos

C) There are currently no specific treatments for WNV and ZIKA

Which of the following is the major vector for WNV? A. Aedes aegypti B. Anopheles gambiae C. Culex pipiens D. none of the above

C. Culex pipiens

What is the BEST way to control the mosquito vector that harbors dengue fever? A. Spraying insecticides around homes and other crowded areas B. Using mosquito nets around sleeping structures C. Reducing the larval source D. Deep cleaning highly crowded areas

C. Reducing the larval source

True/False: The exact mechanisms and sites of WN virus replication following the bite of an infected mosquito are well documented and studied

FALSE, they are unknown

What family of birds is West Nile Virus particularly virulent in within the U.S.? A. Columbidae B. Corvidae C. Turdidae D. Chickadee

Corvidae

What species of mosquitoes transmits West Nile Virus? A. Aedes B. Anopheles C. Culex D. Culiseta

Culex

How many non-structural genes are there in the dengue virus genome? Which end are they located at? A) 3, 5' end B) 3, 3' end C) 7, 5' end D) 7, 3' end

D) 7, 3' end

What factors contribute to the rapid spread of West Nile Virus? I. Birds as animal reservoirs II. Aedes Aegypti are found everywhere in the US III. Aedes Aegypti can survive the cold A. II only B. I and II only C. II and III only D. I, II, and III

D. I. Birds as animal reservoirs II. Aedes Aegypti are found everywhere in the US III. Aedes Aegypti can survive the cold

According to the article "West Nile Virus", a person presents with symptoms of West Nile Virus meningoencephalitis. What is the appropriate course of action you should take in treating this person? A. Care for the patient at home with supportive care. B. Send the patient to hospice care, as there is nothing else that can be done. C. Hospitalize the patient so that they can receive surgery to correct the condition and have them use corticosteroids post-surgery. D. Hospitalize the patient for observation and supportive care and to rule-out treatable Central Nervous System infections/conditions.

D. Hospitalize the patient for observation and supportive care and to rule-out treatable Central Nervous System infections/conditions.

The CDC has a substantial amount of _________ stored in case of emergency with mosquito-transmitted disease. A. Citronella candles B. DDT (Dichlorodiphenyltrichloroethane) C. Acetone D. Sodium Hydroxide

DDT (Dichlorodiphenyltrichloroethane)

Which one of the following is NOT a serotype of Dengue virus? a) DEN-1 b) DEN-2 c) DEN-5 d) DEN-4

DEN-5

What is a primary virulence factor for the WN e ncephalitis virus? A] fimbriae B] surface receptors C] envelope toxins D] virus envelope protien E] capsid protien

D] virus envelope protien

"The critical stage of DHF is at the time of __________..." a) Increased Fever b) Vomiting c) Headache d) Defervescence (decrease of fever)

Defervescence (decrease of fever)

When making a flu vaccine, scientists determine which serotypes are likely to be the most dominant that flu season. Which disease that we studied is similar to the flu in this way and how many serotypes are there?

Dengue, 4 virus serotypes.

What process explains the range differences between Culex mosquitos and Aedes aegypti?

Diapause

True or False: The majority of West Nile viral infections are associated with severe myelitis and myocarditis.

FALSE

What kind of virus is Zika? A. Papovaviridae B. Adenoviridae C. Flaviviridae D. Plasmaviridae

Flaviviridae

In which states can A. aegypti be currently found? (select all that apply) A. Florida B. Hawaii C. Arizona D. California E. Louisiana F. Texas G. Alabama

Florida & Texas

Which of these serologic tests are not used in the diagnosis of Dengue infection? A. Complement fixation B. Hemagglutination-inhibition C. Neutralization test D. Fluorescent treponemal antibody absorption

Fluorescent treponemal antibody absorption

Which best describes the flow of the Zika virus spread from the years 1946 to 2016? a. From East Africa to East Asia to South America b. From West Africa to East Asia to North America c. From North Africa to Australia to South America d. From East Africa to North America to South America

From East Africa to East Asia to South America

All of the following countries experienced an outbreak of West Nile Virus between the years 1950-2000 except: A) Israel B) France C) Germany D) South Africa

Germany

Explain the effect of globalization on the spread of the Zika virus.

Globalization has increased travel, trading and interactions between people from around the globe. Importing goods can create pockets of water where female mosquitoes that carry the virus lay their eggs. These offspring can carry the Zika virus because of vertical transmission and will be ready to infect humans when they hatch.

A 54 year-old male presents to the clinic with slowed reflexes and trouble with fine motor tasks. He also mentions that he recently traveled to French Polynesia for vacation. What could be the potential issue? a. Guillan-Barre Syndrome b. Acute myelitis c. Microcephaly d. The common cold

Guillan-Barre Syndrome

Dengue fever has 4 stereotypes (DEN-1, DEN-2, DEN-3 and DEN-4) and often times these stereotypes can cocirculate in the same city. This is known as ______.

Hyperendemicity

In the article "Dengue and Dengue Hemorrhagic Fever" which of the following is NOT listed as a major contributing factor to the resurgence of Dengue and DHF? A. Inadequate vector control B. Increased international travel by boat C. Population growth D. Rapid uncontrolled urbanization in developing countries

Increased international travel by boat

Which of these is not one of the four isolation systems used for dengue viruses? a. Mammalian Cell Culture b. Intracerebral inoculation of 1-3 day old baby mice c. Mosquito Cell Culture d. Intrafollicular extraction of newly hatched mosquito larvae

Intrafollicular extraction of newly hatched mosquito larvae

Explain the complication of creating a vaccine for the Dengue virus.

It is complicated to create a vaccine for the dengue virus because there exist 4 serotypes of it and there is no cross-immunity among these.

Which of the following is derived from host cells: A. Membrane protein B. Envelope protein C. Lipid Bilayer D. RNA E. Capsid

Lipid Bilayer

Which of these is not a mode of transmission of Zika? A)Blood Transfusion B)Sexual Transmission C)Mosquito Bites D)None of the above

None of the above

What is the animal reservoir for dengue? A.) Birds B.) Horses C.) Primates D.) Bats

Primates

Which of the following is not a modality of transmission of Zika virus? A. Mosquito bites B. Sexual Transmission C. Blood transfusion D. Respiratory droplets

Respiratory droplets

What is the primary cause of death from dengue infections? A.) Severe hemorrhaging B.) Respiratory failure C.) Sepsis D.) Deep vein thrombosis

Severe hemorrhaging

(T/F): According to the article "Dengue and Dengue Hemorrhagic Fever," female Ae. aegypti are nervous feeders, moving from person to person if disrupted and rapidly spreading dengue if infected.

TRUE

True or False? According to the article "Dengue and Dengue Hemorrhagic Fever", the factors responsible for the resurgence/emergence of dengue include huge global population growth, increased yet unplanned urbanization, lack of effective mosquito control in areas where dengue is endemic, increased air travel, and decay in public health infrastructures in most countries in the past 30 years.

TRUE

True/False Thrombocytopenia, a condition that consists of a persistent decrease in the number of platelets in the blood, is a common symptom of dengue fever.

TRUE

What could be the benefits and consequences of Yellow Fever using transovarial transmission?

The benefits of being vertically transmitted may provide a way for Yellow Fever to survive during unfavorable conditions, allowing it to survive harsher climatic conditions or in the absence of a suitable host by using their vector to reproduce and pass on the virus to their offspring. Transovarial transmission could lead Yellow Fever to have low virulence, which can have positives and negatives. Being highly virulent could cause death before reproduction, so keeping a low virulence due to the vertical transmission could be beneficial. However, low virulence and vertical transmission could cause a bottleneck effect, leading to issues described by Muller's Ratchet, especially since RNA has a higher chance of mutating. In addition, if a suitable host did appear, the low virulence in vertical transmission might've led to a lower fitness due to a reduced natural selection that favors high viral reproduction, leading to a continued loop of reduced virulence.

Describe the 3 main reasons why WNV is distributed across the US compared to DENV.

The first reason is that birds are the reservoir host for West Nile Virus. This allows the virus to travel across the US very quickly, and complete the transmission cycle to humans. The second reason is that the vector Culex pipiens is distributed across the US and can be found in any state. So that means the reservoir of the virus is across the US, and so is the vector that spreads it. The last reason is that C. pipiens can survive winter by entering diapause. In diapause, the mosquitoes suspend development and don't lay eggs until the spring, Once the weather warms, the females lay eggs and transmit the virus vertically to their offspring.

Why is the West Nile virus far more pervasive in the United States when compared to the Zika virus?

The principal animal reservoir for the Zika virus is the monkey. Monkeys have no natural habitat within the United States, meaning that most Zika cases are related to travel rather than local transmission. Additionally, the West Nile virus (WNV) has a variety of advantages that make it ideal to rapidly spread within the highly urbanized regions of the United States.

(Has a picture) What circumstances caused this regression and reemergence of A. aegypti in the Americas?

The regression of A. aegypti was due to the campaign to eradicate the species using insecticides. Eventually the campaign was discontinued because the DDT in the insecticide is very dangerous when inhaled by humans. This dicontinuation of the insecticide campaign allowed A. aegypti to reemerge and flourish in the Americas.

What is one established fact that supports enzootic cycles of West Nile virus in the United States?

The virus has been active in the united states for four consecutive transmission seasons, OR The detection of WNV in Florida in June suggests that the virus was introduced earlier than 2000 OR The virus has been observed to be present throughout most of the eastern parts of the USA OR The West nile virus can infect a broad species of avian host and vector mosquito species.

Which is not a shared characteristic of West Nile Virus and Zika Virus? A. Single-Stranded B. RNA Virus C. Transmitted by Aedes Aegypti only D. Family: Flaviviridae, Genus: Flavivirus

Transmitted by Aedes Aegypti only

How does vertical transmission affect the maintenance of yellow fever, dengue, West Nile Virus, and other mosquito-transmitted NTDs? A. It allows mosquitos to travel vertically, extending their reach to the north and south. B. Vertical transmission allows the diseases to continue to survive even when there are no other organisms outside of the mosquitoes to infect and spread the disease to, furthering its influence and life. C. It allows a decreased frequency of mating and reproduction so mosquitoes can take over more areas. D. None of the above

Vertical transmission allows the diseases to continue to survive even when there are no other organisms outside of the mosquitoes to infect and spread the disease to, furthering its influence and life.

The world has dumped resources into developing a tetravalent vaccine for Dengue fever. Through this research, many different candidates have been presented. What type of vaccine below has NOT been considered as a potential vaccine type? I. Attenuated live vaccine II. Inactivated whole-virion vaccine III. mRNA vaccine IV. Toxoid vaccine V. Subunit vaccine a) I, III, V b) III, IV c) III only d) II, V e) I, II, III

b) III, IV

During what period can an infected individual transmit Dengue to a biting mosquito? a. incubation b. acute febrile c. extrinsic incubation d. vertical transmission

b. acute febrile

The West Nile virus can typically be isolated in what is called "peak viraemia," which is generally between how many days following infection? a. between 0-1 days b. between 2-4 days c. between 5-7 days d. between 1-2 weeks

between 2-4 days

Where is the final target zone for virus replication in a mosquito that facilitates transmission to host? A)Proboscis B)Antennae C)glands D)Mid-gut

glands

Which piece of evidence did not help researchers determine the urban transmission cycle. a. Absence of monkeys in Yap State b. Humans are infected as an accidental host c. scale of the recent outbreaks d. low viremia in Zika infected people

low viremia in Zika infected people

Why is transovarial transmission significant to the spread of yellow fever? a) it ensures the virus stays within the area it originated b) it keeps the virus from infecting more than one species c) mosquito eggs increase the spread of the virus around the world by trade/commerce d) mosquitos are unable to pass the virus to their offspring

mosquito eggs increase the spread of the virus around the world by trade/commerce

What are the methods of control for West Nile Virus and Zika virus?

mosquito spraying and public education

Which of the following best describes the genome of the Zika virus? A] negative-sense single strand of DNA B] negative-sense double strand of DNA C] positive-sense single strand of RNA D] positive-sense double strand of RNA E] positive-sense double strand of DNA

positive-sense single strand of RNA

What class of virus does West Nile Virus belong to? A. dsDNA B. ssDNA C. dsRNA D. ssRNA

ssRNA

Which of the following does not apply to the Zika virus? a) family Flaviviridae, genus flavivirus b) transmitted to humans primarily by Culex mosquitos species c) single-stranded, enveloped RNA virus d) closely related to Dengue virus

transmitted to humans primarily by Culex mosquitos species

About how many kilo base pairs are there in the single stranded RNA genome of the Yellow Fever/Dengue virus? a. ~10 b. ~11 c. ~12 d. ~13

~11