Suspected Chandipura virus infection in Gujarat UPSC

CHANDIPURA VIRUS INFECTION

Source: INDIANEXPRESS

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Context

The Gujarat government said that six children have died of suspected Chandipura virus (CHPV) infection in the state since July 10.
So far, a total of 12 suspected cases have been reported.

Details

Chandipura virus (CHPV) is an arbovirus from the Rhabdoviridae family, first identified in Maharashtra in 1965.
It is primarily transmitted by sandflies and can cause severe brain inflammation, leading to rapid progression and high mortality rates, especially in children.

Transmission and Hosts

Vectors:Phlebotomine sandflies, Phlebotomus papatasi, and some mosquitoes like Aedes aegypti.
Hosts:Primarily affects children under 15 and can infect domestic animals.

Symptoms

Initial flu-like symptoms: fever, body ache, headache
Progression to neurological symptoms: altered mental state, seizures, encephalitis
Other symptoms: respiratory distress, bleeding tendencies, anemia
Rapid progression often leads to death within 24-48 hours after hospitalization

Diagnosis

PCR (Polymerase Chain Reaction)
ELISA (Enzyme-Linked Immunosorbent Assay)
Virus isolation

PCR AND ELISA

Polymerase Chain Reaction (PCR)
Polymerase Chain Reaction (PCR) is a widely used laboratory technique in molecular biology to amplify specific DNA sequences. It was developed by Kary Mullis in 1983. The process involves the following steps:

Denaturation: The double-stranded DNA is heated to separate it into two single strands.
Annealing: The temperature is lowered to allow primers to attach to the DNA template.
Extension: DNA polymerase extends the primers to form a new DNA strand.

PCR is essential for various applications, including genetic research, medical diagnostics, forensic science, and biotechnology. It allows for the detection and analysis of DNA even from small or degraded samples.

Enzyme-Linked Immunosorbent Assay (ELISA)
Enzyme-Linked Immunosorbent Assay (ELISA) is a common laboratory technique used to detect and quantify antigens (proteins, hormones, and antibodies) in a sample. The procedure involves the following steps:

Coating: An antigen is immobilized on a solid surface, typically a microplate.
Blocking: Non-specific binding sites are blocked with a blocking agent.
Binding: A specific antibody is added, which binds to the antigen.
Detection: A secondary antibody, conjugated with an enzyme, binds to the primary antibody.
Substrate Addition: A substrate is added, which the enzyme converts into a detectable signal, usually a color change.

ELISA is widely used in diagnostics for diseases, including HIV, and in various research applications to measure the concentration of substances in biological samples. It is valued for its sensitivity, specificity, and versatility.

Treatment

No specific antiviral treatment or vaccine
Supportive care: hydration, electrolyte balance, anticonvulsants, intensive care

Prevention

Vector control: reducing sandfly populations
Use of insect repellents and protective clothing
Public health education

Epidemiology

Endemic regions:Central India
Notable outbreaks:Maharashtra, Gujarat, Andhra Pradesh
Recent cases:Six children died in Gujarat in July 2024, with a total of 12 suspected cases.

Affected Regions and Patterns

Outbreaks often in rural and tribal areas with higher sandfly populations
Increased during monsoon seasons
Changes in disease patterns and vector behavior over the years

Arboviruses

Arboviruses (arthropod-borne viruses) are viruses transmitted by arthropods, such as mosquitoes and ticks.
These viruses can cause a range of diseases in humans and animals.

Category	Details
Definition	Viruses transmitted by arthropods (e.g., mosquitoes, ticks).
Transmission Vectors	Mosquitoes (e.g., Aedes, Culex), Ticks (e.g., Ixodes), Sandflies, and other arthropods.
Human Diseases	Dengue Fever, Zika Virus, Chikungunya, Yellow Fever, West Nile Virus, Japanese Encephalitis.
Symptoms	Fever, headache, rash, joint pain, muscle pain, hemorrhage, encephalitis (varies by virus).
Geographical Spread	Tropical and subtropical regions; some arboviruses are found in temperate zones.
Prevention	Vector control (e.g., mosquito nets, insect repellents), vaccination (for specific viruses), surveillance.
Diagnosis	Serological tests (e.g., ELISA), molecular tests (e.g., PCR), viral culture.
Treatment	Mostly supportive care; antiviral treatments are limited; vaccines available for some (e.g., Yellow Fever).
Notable Arboviruses	Dengue Virus, Zika Virus, Chikungunya Virus, Yellow Fever Virus, West Nile Virus, Japanese Encephalitis Virus.

Global Arbovirus Initiative

Aspect	Details
Objective	To enhance global capacity to detect, prevent, and control arbovirus outbreaks.
Initiating Organization	World Health Organization (WHO).
Key Activities	- Strengthening surveillance systems for early detection.
	- Coordinating research efforts to develop vaccines and treatments.
	- Enhancing public health response capabilities.
	- Promoting vector control strategies.
	- Facilitating information sharing and collaboration among countries.
Significance	Addresses the rising threat of arbovirus outbreaks due to factors like climate change and urbanization.
Impact	Aims to reduce the incidence and burden of arbovirus-related diseases globally.

Sandflies

Aspect	Details
Scientific Family	Psychodidae
Subfamily	Phlebotominae
Common Genera	Phlebotomus (Old World), Lutzomyia (New World)
Distribution	Tropical and subtropical regions, including parts of Asia, Africa, the Americas, and the Mediterranean
Habitat	Humid environments; typically found in forested areas, caves, and animal burrows
Behavior	Nocturnal; most active during dawn and dusk
Feeding	Female sandflies feed on blood for egg development; males feed on plant juices
Reproduction	Females lay eggs in moist environments; larvae develop in organic-rich soil
Disease Transmission	Vectors for diseases like leishmaniasis, Chandipura virus, and bartonellosis
Control Measures	Insect repellents, bed nets, environmental management to reduce breeding sites

Rhabdoviridae family

Aspect	Details
Scientific Classification	Family: Rhabdoviridae
Genome	Single-stranded negative-sense RNA
Structure	Enveloped, bullet-shaped or bacilliform virions
Genera	Lyssavirus, Vesiculovirus, Novirhabdovirus, and more
Notable Species	Rabies virus (Lyssavirus), Vesicular stomatitis virus (Vesiculovirus), Chandipura virus (Vesiculovirus)
Hosts	Vertebrates (mammals, fish) and invertebrates (insects)
Transmission	Bites (e.g., rabies), insect vectors (e.g., sandflies for Chandipura virus)
Diseases	Rabies, vesicular stomatitis, encephalitis (e.g., Chandipura virus infection)
Diagnosis	PCR, ELISA, virus isolation
Prevention	Vaccination (e.g., rabies), vector control, protective clothing

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Sources:

INDIANEXPRESS

PRACTICE QUESTION

Q: With reference to the Rhabdoviridae family, consider the following statements:

The Rhabdoviridae family includes viruses that infect animals, plants, and humans.
Rabies virus is a member of the Rhabdoviridae family.
All Rhabdoviridae viruses have a segmented genome.

Which of the statements given above is/are correct?

(a) 1 and 2 only

(b) 2 and 3 only

(d) 1, 2, and 3

Answer: (a)