Bat-Borne and Rodent-Borne Viral Diseases

Question 1

Hantaviruses
(a) Family
(b) Order
(c) Genus
(d) Mode of transmission
(e) Basic structure and genome type

Answer 1

(a) Family: Hantaviridae
(b) Order: Bunyavirales
(c) Genus: Orthohantavirus
(d) Mode of transmission: contact with infected rodents and their excreta
(e) Basic structure and genome type: enveloped, three segments of negative-sense single stranded RNA viruses [Small (S) segment, Medium (M) segment, Large (L) segment]

[Diagram] [Diagram 2]

Question 2

Briefly state the role of each of the three segments of the Hantavirus genome.

Answer 2

🐀 Small (S) segment: Encodes the nucleocapsid protein (N protein), which is crucial for RNA encapsidation and protection.
🐀 Medium (M) segment: Encodes the glycoproteins (Gn and Gc), which are involved in virus attachment and entry into host cells.
🐀 Large (L) segment: Encodes the RNA-dependent RNA polymerase (RdRp), which is essential for viral RNA replication and transcription.
[Diagram 2]

Question 3

Name the two syndromes caused by Hantaviruses and state
(a) symptoms
(b) their respective regions of prevalence.

Answer 3

(1) Hantavirus Pulmonary Syndrome also calledHantavirus Cardiopulmonary Syndrome
Symptoms: fatigue, fever, muscle aches, coughing, shortness of breath, fluid build up in lungs, low blood pressure
Region of prevalence: Americas

(2) Hemorrhagic Fever with Renal Syndrome
Symptoms: intense headaches, back and abdominal pain, fever, chills, low blood pressure, acute shock, kidney failure
Region of prevalence: Europe, Asia

Question 4

Briefly discuss diagnosis and treatment of HPS and HFRS.

Answer 4

Hantavirus Pulmonary Syndrome
🐀 Diagnosis:
(1) Serology: Detection of hantavirus-specific IgM and IgG antibodies using enzyme-linked immunosorbent assay (ELISA).
(2) PCR: Polymerase chain reaction (PCR) to detect viral RNA in blood or tissue samples.
(3) Chest X-ray: To identify pulmonary edema and other lung abnormalities.

🐀 Treatment:
Treatment is supportive: oxygen therapy, mechanical ventilation, fluid management to prevent fluid overload and pulmonary edema.
[Some studies have explored the use of the antiviral drug ribavirin, but its effectiveness remains uncertain and it is not widely used.]

Hemorrhagic Fever with Renal Syndrome
🐀 Diagnosis:
(1) Serology: Detection of hantavirus-specific antibodies using ELISA.
(2) PCR: Detection of viral RNA in blood or tissue samples.
(3) Urinalysis and Blood Tests: To assess kidney function and detect signs of renal impairment.

🐀 Treatment is supportive: fluid management to maintain fluid and electrolyte balance, dialysis in case of acute kidney failure

Question 5

Briefly discuss prevention of Hantavirus infection.

Answer 5

🐀 Rodent control to reduce exposure to rodents and their excreta.
🐀 Encouraging proper hygiene practices, such as wearing gloves and masks when cleaning areas contaminated by rodents, can help prevent infection.

Question 6

List some bat-borne viruses.

Answer 6

Coronavirus, Rabies, Nipah, Ebola

Question 7

Ebola virus
(a) Family
(b) Genus
(c) Basic structure
(d) Genome type

Answer 7

(a) Family: Filoviridae
(b) Genus: Ebolavirus
(c) Basic structure: enveloped, helical
(d) Genome type: negative-sense, single-stranded RNA

[Diagram 1] [Diagram 2] [Diagram 3] [Image 1] [Image 2]

Question 8

Name the 3 genera of Filoviridae.

Answer 8

1. Cuevavirus
   
   2. Marburgvirus
   3. Ebolavirus