biology

Venezuelan hemorrhagic fever

Venezuelan hemorrhagic fever is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Venezuelan hemorrhagic fever rather than just read about it. In short: Venezuelan hemorrhagic fever (VHF) is a zoonotic human illness first identified in 1989. The disease is most prevalent in several rural areas of central Venezuela and is caused by Guanarito virus (GTOV) which belongs to the Arenaviridae family.

Key takeaways

Venezuelan hemorrhagic fever belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Venezuelan hemorrhagic fever to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Venezuelan hemorrhagic fever from memory before moving on to harder problems.

Reference excerpt

Venezuelan hemorrhagic fever (VHF) is a zoonotic human illness first identified in 1989. The disease is most prevalent in several rural areas of central Venezuela and is caused by Guanarito virus (GTOV) which belongs to the Arenaviridae family. The short-tailed cane mouse (Zygodontomys brevicauda) is the main host for GTOV which is spread mostly by inhalation of aerosolized droplets of saliva, respiratory secretions, urine, or blood from infected rodents. Person-to-person spread is possible, but uncommon.

Presentation VHF has many similarities to Lassa fever and to the arenavirus hemorrhagic fevers that occur in Argentina and Bolivia. It causes fever and malaise followed by hemorrhagic manifestations and convulsions. Some presentations of the virus are also characterized by vascular damage, bleeding diathesis, fever, and multiple organ involvement. Clinical diagnosis of VHF has proven to be difficult based on the nonspecific symptoms. The disease is fatal in 30% of cases and is endemic to Portuguesa state and Barinas state in Venezuela. Treatment and prevention for the VHF virus are limited and there are currently no licensed vaccines available that can act to prevent the disease. However, once infected, ribavirin, an anti-viral drug given intravenously, is one way to treat VHF.

Virus Arenaviruses are enveloped, single-stranded, bisegmented RNA viruses with antisense genomes. Based on their antigenic properties, arenaviruses have been classified into two major groups: the Old World arenaviruses, and the New World arenaviruses. Old World arenaviruses include lymphocytic choriomeningitis virus and Lassa virus. New world arena viruses are further broken down into three clades, A, B, and C. The Guanarito arena virus belongs to clade B and is the cause of VHF. On the biosafety level scale of one to four, with four causing the most risk, the viruses causing hemorrhagic fevers have been assigned a four by the CDC.

Host The short-tailed cane mouse, the main host of GTOV, is native to western Venezuela and resides in large numbers in tall grass, cultivated agricultural fields, human homes, and outbuildings. It is speculated that demographic and ecological changes in the rural areas increased the frequency of contact between humans and infected rodents such that VHF emerged.

History From September 1989 through December 2006, the State of Portuguesa recorded 618 cases of VHF. Nearly all of the cases were individuals who worked or lived in Guanarito during the time they became infected. The case fatality rate was 23.1%. Because the virus is contracted by aerosol dissemination, concern arose shortly after the first cases emerged in 1989 due to fear of biological warfare. Potential biological terrorism agents were identified and categorized in 1999 by the Centers for Disease Control and Prevention (CDC) as part of the Congressional initiative to further response capabilities to biological weapons. Arenaviruses causing hemorrhagic fevers, along with a genus of virus called filoviruses, were categorized in Category A; these are pathogens with the highest potential impact on public health safety. A notable event in the timeline of this virus' scientific knowledge was the unexplained disappearance of a vial of the virus at the University of Texas Medical Branch Galveston National Laboratory, announced 2013 March 24.

References

External links

Worked examples

Example 1 — a first encounter with Venezuelan hemorrhagic fever

Start with the simplest possible case. Write down what Venezuelan hemorrhagic fever claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Venezuelan hemorrhagic fever before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Venezuelan hemorrhagic fever ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Venezuelan hemorrhagic fever

In research: Venezuelan hemorrhagic fever appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Venezuelan hemorrhagic fever in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Venezuelan hemorrhagic fever is common in secondary-school and first-year university syllabi. It links to neighbouring topics Animal viral diseases, Hemorrhagic fevers, Rodent-carried diseases, so understanding it makes those chapters shorter.
In everyday life: Look for Venezuelan hemorrhagic fever outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Venezuelan hemorrhagic fever in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Venezuelan hemorrhagic fever means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Venezuelan hemorrhagic fever out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Venezuelan hemorrhagic fever in simple terms?

Why does Venezuelan hemorrhagic fever matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Venezuelan hemorrhagic fever?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Venezuelan hemorrhagic fever.