Diseases caused by viruses Questions in English

(D) Yellow fever is a viral disease caused by the yellow fever virus and is transmitted by the $Aedes$ $aegypti$ mosquito.
Dengue is also a viral disease caused by the dengue virus and is primarily transmitted by the $Aedes$ $aegypti$ mosquito.
Elephantiasis is caused by a filarial worm (parasite),sleeping sickness is caused by a protozoan $(Trypanosoma)$,and encephalitis can be caused by various agents including viruses,but the specific pair that is both viral and mosquito-borne is yellow fever and dengue.

(C) Rabies (hydrophobia) is a viral disease caused by the rabies virus (a rhabdovirus).
It is transmitted to humans through the saliva of infected animals (like dogs,cats,or bats) via bites or scratches.
The virus is neurotropic,meaning it travels to the central nervous system $(CNS)$,causing encephalitis,hydrophobia (fear of water),muscle spasms,paralysis,and eventually death.
Since the causative agent is a virus and not a bacterium,the Reason provided is incorrect.

(A) The common cold is one of the most infectious human diseases.
It is caused by a group of viruses known as $Rhinoviruses$.
These viruses infect the nose and respiratory passage but not the lungs.
The infection is transmitted through droplets resulting from coughs or sneezes of an infected person,either inhaled directly or transmitted through contaminated objects such as pens,books,cups,doorknobs,or computer keyboards.
The symptoms of the common cold typically include nasal congestion and discharge,sore throat,hoarseness,cough,headache,and tiredness,which usually last for $3-7$ days.

(N/A) Globalization and increased human mobility have significantly accelerated the spread of infectious diseases across international borders.
In the case of the $H_5N_1$ virus (Avian Influenza),the rapid movement of migratory birds and the global trade of poultry products facilitate the transmission of the virus to new geographical regions.
Once the virus enters a human population,the high frequency of international travel allows it to spread rapidly from one country to another.
If the virus develops the ability to transmit efficiently from human to human,the global connectivity of modern society ensures that it can reach pandemic proportions in a very short time.

(C) The common cold is a viral infectious disease of the upper respiratory tract.
It is primarily caused by the $Rhino$ $viruses$,which infect the nose and respiratory passages.
These viruses are responsible for $10-40\%$ of all common colds.
Therefore,the correct option is $C$.

(B) Dengue fever is a viral disease caused by the dengue virus $(DENV)$.
It is transmitted to humans primarily through the bite of an infected female $Aedes$ $aegypti$ mosquito.
While the virus is the causative agent,the mosquito acts as the vector that spreads the disease from one person to another.
Therefore,the correct answer is $B$ (Mosquito).

(C) The common cold is caused by the Rhino virus.
It infects the nose and respiratory passage but does not affect the lungs.
Pneumococcus causes pneumonia,which specifically infects the alveoli of the lungs.
Shigella dysenteriae causes dysentery,which affects the gastrointestinal tract.
Therefore,the correct answer is the Rhino virus.

(A) Swine flu is a respiratory disease caused by the influenza $A$ virus,specifically the $H1N1$ strain. This virus is a subtype of the influenza $A$ virus that originated in pigs but can infect humans. It spreads through respiratory droplets when an infected person coughs or sneezes.

(B) The Variola virus is the causative agent of Smallpox.
Smallpox was a highly contagious and deadly disease characterized by high fever and a characteristic skin rash.
It was officially declared eradicated by the World Health Organization $(WHO)$ in $1980$ due to successful global vaccination campaigns.
Measles is caused by the Measles virus,Chickenpox by the Varicella-zoster virus,and Mumps by the Mumps virus.

(A) $HTLV$ stands for Human $T$-cell Lymphotropic Virus. It is a group of retroviruses that are known to infect human $T$-cells. These viruses are associated with certain types of leukemia and lymphoma,such as Adult $T$-cell Leukemia/Lymphoma $(ATL)$. Therefore,the correct full form is Human $T$-cell Lymphotropic Virus.

(C) $SARS$ stands for Severe Acute Respiratory Syndrome. It is a viral respiratory disease caused by the $SARS-associated$ coronavirus $(SARS-CoV)$,which is a member of the coronavirus family.

(C) Let's analyze each statement:
$(1)$ $HIV$ (Human Immunodeficiency Virus) was previously referred to as $HTLV-III$ (Human $T$-lymphotropic virus type $III$) or $LAV$. While it is a virus,the statement is technically imprecise regarding the nomenclature history,but statement $(5)$ is factually incorrect as $Neisseria$ $gonorrhoeae$ is a bacterium,not a virus.
$(2)$ Rabies virus is indeed transmitted through the saliva of infected animals like dogs. (Correct)
$(3)$ Mumps is a viral infection affecting the parotid glands. (Correct)
$(4)$ Herpes simplex virus $(HSV)$ causes genital herpes. (Correct)
$(5)$ Gonorrhea is caused by the bacterium $Neisseria$ $gonorrhoeae$. Since the question asks about viral diseases,this statement is incorrect. (Incorrect)
$(6)$ Dengue is caused by the Dengue virus. (Correct)
Thus,statement $(1)$ (due to nomenclature inaccuracy) and statement $(5)$ (due to being a bacterial disease) are considered incorrect in the context of viral diseases. Therefore,$4$ statements are correct and $2$ are incorrect.

(C) The consumption of eggs and chicken was significantly affected due to the outbreak of the $H5N1$ virus,commonly known as the $Bird \ flu$ virus. This viral disease primarily affects birds,including poultry like chickens and ducks. When outbreaks occur,it leads to mass culling of birds to prevent the spread of the infection to humans,which causes a sharp decline in the demand and consumption of poultry products due to public health concerns.

(C) Adenoviruses are a group of viruses that typically cause respiratory illnesses,such as the common cold,bronchitis,pneumonia,and sore throat.
Bacteriophages are viruses that infect bacteria.
Baculoviruses are pathogens that attack insects and other arthropods.
$TMV$ (Tobacco Mosaic Virus) is a plant virus that infects tobacco and other plants.
Therefore,the correct option is $C$.

(B) $SARS$ (Severe Acute Respiratory Syndrome) is a viral respiratory illness. It is caused by the $SARS-CoV$ virus,which belongs to the Coronaviridae family. This family also includes viruses that cause the common cold. Therefore,$SARS$ is related to the corona virus family.

(B) Poliomyelitis is a viral disease caused by the poliovirus,which leads to muscle weakness and paralysis.
Atrophy is a condition characterized by the degeneration or wasting away of muscle tissue,which can occur due to various factors like cancer,$AIDS$,or $COPD$.
Dystrophy refers to a group of genetic disorders,such as muscular dystrophy,caused by the inability to produce functional dystrophin protein.
Muscular hypertrophy is the increase in the size of muscle cells,commonly observed in individuals who engage in intensive resistance training,such as bodybuilders.

(D) Bird flu is caused by a virus. Specifically,it is caused by the avian influenza virus,most commonly the $H5N1$ strain.
It is a viral disease that primarily affects birds but can occasionally infect humans through direct contact with infected poultry or contaminated environments.

(D) The bird flu virus (Avian Influenza) is heat-sensitive.
Cooking poultry products such as chicken and eggs at temperatures above $70^{\circ}C$ effectively kills the virus.
Since the question specifies cooking at temperatures above $100^{\circ}C$, the virus is completely destroyed, and there is no risk of contracting the disease through consumption.

(B) Hepatitis-$A$ virus contains $ssRNA$ as its genetic material.
Hepatitis-$B$ virus contains $dsDNA$ as its genetic material and is primarily transmitted through sexual contact,blood transfusion,and from infected mother to fetus.
Hepatitis-$C$ virus contains $ssRNA$ as its genetic material.
Hepatitis-$D$ and Hepatitis-$E$ viruses also contain $ssRNA$ as their genetic material.
Therefore,Hepatitis-$B$ is the correct answer.

(C) Measles is a viral disease caused by the measles virus.
In contrast, cholera is caused by the bacterium $Vibrio \text{ } cholerae$, diphtheria is caused by $Corynebacterium \text{ } diphtheriae$, and whooping cough (pertussis) is caused by $Bordetella \text{ } pertussis$.

(D) Interferons are antiviral proteins produced by virus-infected cells to protect healthy cells from further viral infection.
Since interferons specifically target viral replication, their presence indicates a viral infection.
Among the given options, Typhoid is caused by the bacterium $Salmonella \text{ } typhi$, Filariasis is caused by nematodes (worms), and Malaria is caused by the protozoan $Plasmodium$.
Measles is a disease caused by the measles virus $(Morbillivirus)$.
Therefore, the presence of interferon suggests an infection of Measles.

(B) The common cold is caused by a group of viruses known as Rhinoviruses. These viruses infect the nose and respiratory passage but do not infect the lungs. Therefore,the statement that Rhinovirus infects the lungs is incorrect.

(D) $Aedes$ mosquito is the primary vector for both $Chikungunya$ and $Dengue$ viruses.
$Culex$ mosquito is the vector of $Wuchereria$ $bancrofti$,which causes $Elephantiasis$ (filariasis).
$Xenopsylla$ (Rat flea) is the vector of $Yersinia$ $pestis$,which causes $Plague$.
$Anopheles$ mosquito is the vector of $Plasmodium$,which causes $Malaria$.

(A) The causative agents of the common cold are $Rhinoviruses$,which are a group of viruses responsible for most infectious human ailments.
These viruses specifically infect the nose and respiratory passage but do not affect the lungs.
$\Rightarrow$ The common cold is characterized by symptoms such as nasal congestion and discharge,sore throat,hoarseness,cough,headache,and tiredness.
These symptoms typically last for $3$ to $7$ days.
Transmission occurs when droplets resulting from the cough or sneezes of an infected person are inhaled directly or transmitted through contaminated objects such as pens,books,cups,doorknobs,computer keyboards,and mice,leading to infection in a healthy person.

(C) Let us analyze the causative agents for each disease:
$1$. Mumps: Caused by the Mumps virus (Viral).
$2$. Smallpox: Caused by the Variola virus (Viral).
$3$. Common cold: Caused by Rhinoviruses (Viral).
$4$. Typhoid: Caused by the bacterium Salmonella typhi (Bacterial).
$5$. Herpes: Caused by the Herpes simplex virus (Viral).
$6$. $AIDS$: Caused by the Human Immunodeficiency Virus $(HIV)$ (Viral).
$7$. Hepatitis-$B$: Caused by the Hepatitis $B$ virus $(HBV)$ (Viral).
$8$. Pneumonia: Primarily caused by bacteria like Streptococcus pneumoniae (Bacterial),though it can have other causes.
Counting the viral diseases: Mumps,Smallpox,Common cold,Herpes,$AIDS$,and Hepatitis-$B$ are all viral.
Total count = $6$.

(A) Dengue and chikungunya are viral diseases transmitted to humans through the bite of infected mosquitoes.
Specifically, the $Aedes$ mosquito (primarily $Aedes$ $aegypti$) acts as the vector for both the dengue virus and the chikungunya virus.
$Anopheles$ mosquitoes are vectors for malaria, while $Culex$ mosquitoes are known vectors for diseases like filariasis and Japanese encephalitis.
Therefore, the correct answer is $Aedes$.

(D) The common cold is a viral infectious disease of the upper respiratory tract.
Symptoms typically include nasal congestion and discharge,sore throat,hoarseness,cough,headache,and fatigue.
These symptoms usually last for $3-7$ days.
In the common cold,the infection is restricted to the nose and respiratory passage and does not affect the lungs.
Therefore,infection in the lungs is $NOT$ a symptom of the common cold.

(C) Dengue and Chikungunya.
$Dengue$ is a mosquito-borne viral infection caused by the $Dengue$ virus,transmitted by infected female $Aedes$ $aegypti$ mosquitoes.
$Chikungunya$ is also a mosquito-borne viral disease. The virus is transmitted from human to human by the bite of an infected female $Aedes$ $aegypti$ mosquito.

(C) The correct answer is $C$.
Common cold is a viral infectious disease of the upper respiratory tract.
It is primarily caused by a group of viruses known as Rhinoviruses.
These viruses infect the nose and throat,leading to symptoms such as sneezing,sore throat,cough,and nasal congestion.

(B) Rhinovirus.
The common cold,also known as rhinitis,is caused mainly by rhinoviruses.
These viruses infect the upper respiratory tract but do not affect the lungs.
The characteristic symptoms include nasal congestion,cough,headache,hoarseness,and sore throat.

(A) $Interferons$ are antiviral proteins produced by virus-infected cells to protect non-infected cells from further viral infection.
Among the given options,measles is a viral disease caused by the $Measles$ $virus$.
Tetanus and anthrax are bacterial diseases,and malaria is a protozoan disease.
Therefore,the production of $interferons$ is a characteristic response to a viral infection like measles.