Virology

Differences Between Bacteria and Viruses 

Viruses are strict obligate intracellular parasites, incapable of replication without living hosts. Due to the lack of independent replication capability, viruses are considered non-living things. 

Monkeypox vs Chickenpox

Chickenpox and monkeypox share some symptoms but there are some major differences between these two diseases

Monkeypox: Frequently asked questions

The monkeypox virus is the causative agent of monkeypox. It was first reported from the Democratic Republic of Congo (DRC).

Hepatitis C: Structure, Pathogenesis, and Diagnosis

Hepatitis C is an RNA virus of the genus hepacivirus belonging to the family Flaviviridae. Hepatitis from this virus progresses to chronic condition.

Bacteriophages: Discovery, Detection, and Applications

Bacteriophages are viruses that infect bacteria and archaea. They have a simple structure with genetic materials covered in a protein coat.

Varicella-Zoster Virus (VZV): Chicken Pox and Shingles

Varicella-Zoster virus (VZV) is a DNA virus that belongs to the α-herpesvirus family.

Hepatitis B: Structure, Pathogenesis, and Diagnosis

Hepatitis B virus is a DNA virus belonging to the family hepadnavirus and is responsible for causing acute and chronic hepatitis

Hepatitis A Virus: Structure, Pathogenesis, and Diagnosis

Hepatitis A virus is an RNA virus that is the leading cause of infectious hepatitis worldwide and transmitted by feco-oral route.

Killed or Live Vaccine, Which One to Choose?

Live, attenuated vaccines and inactivated vaccines are two basic types of vaccines used to protect susceptible individuals from infectious diseases.

Virus: Structural Properties and Diseases

Viruses are genetic elements that cannot replicate independently of a living host cell.

Ct Value in SARS-CoV-2 RT-PCR

A low Ct indicates a high concentration of viral genetic material, which is typically associated with a high risk of infectivity.

5 Most Dangerous Viral Infections In History

Ebola virus disease, HIV, Influenza, Small Pox and COVID-19 can be taken as five deadliest viral disease of this century.

Antigen Testing for COVID-19: Principle, Procedure, Results

Antigen tests for SARS-CoV-2 are generally less sensitive than RT-PCR and other NAATs.

mRNA Vaccine: What it is and How it works?

mRNA vaccines teach our cells how to make a protein. This protein triggers an immune response inside our bodies.

Bacteriophage: Structure, Replication, Uses

Bacteriophage is a type of virus that infects and replicates within bacteria and archaea. Current use includes vector and potential antibacterial agent.

Cytopathic effect (CPE) of Viruses: Types with Examples

Cytopathic effect (CPE) refers to morphological changes in host cells because of viral infection. It may aid in viral disease diagnosis.

Shell Vial Cell Culture

Shell vial culture involves inoculation of the clinical specimen on cell monolayer for rapid detection of viruses in vitro.

Neutralization Test for Virus and Toxins

When microbial toxins and specific antibodies combine and the active portion of the toxins are blocked, neutralization occurs.

Indirect Fluorescent Antibody (IFA) Test

Indirect fluorescent antibody test (IFA) is a semi-quantitative, sensitive, and rapid test to detect specific antibodies or antigens.

Embryonated Egg Cultures for Viruses

Embryonated chicken eggs are used for the cultivation of some viruses. The viruses grow in the cells of the embryo and membranes.

COVID-19 Testing Kits That You Should Only Use According To FDA

SARS-CoV-2 IgG/IgM Rapid Test for the diagnosis of COVID-19

Collection and Transport of Nasopharyngeal Swab

Nasopharyngeal swab is the preferred sample for the diagnosis of respiratory syncytial virus (RSV), SARS-CoV-2, influenza virus infections.

Testing Methods for COVID-19 (SARS-CoV-2)

Manufacturers have developed commercial tests for the diagnosis of COVID-19 based on unique gene detection, antigen detection or serological assays.

SARS-CoV-2: Properties, Transmission, and Prevention

SARS-CoV-2, a SS-RNA virus is a member of the Coronaviridae family that causes COVID-19 pandemic.

Viral Transport Media (VTM): Preparation, Uses

Viral Transport Media (VTM) are suitable for collection, transport, maintenance and long-term freeze storage of clinical specimens containing viruses.

Rapid detection of SARS-CoV-2: Diagnosis of COVID-19

Antigens in disease diagnosis

Detection of specific antigens present in the sample (blood, urine, or CSF) using specific antibodies is the mainstay for the rapid diagnosis of infections.

Bacteriophage Plaque Assay: Principle, Procedure, Results

Lysis of the bacteriophage is indicated by the formation of a zone of clearing or plaque within the lawn of bacteria.

Respiratory Syncytial Virus (RSV): Replication, Pathogenesis

RSV is a most common cause of pneumonia and bronchiolitis in infants and young children.

Animal Cell Culture: Types, Applications

Cells used to culture are fibroblast, lymphocytes, cells from cardiac and skeletal tissues, cells from liver, breast, skin, kidney, and tumor cells.

Western Blot Technique: Principle, Steps, Uses

Western blotting or immunoblotting enables researchers to identify the specific protein from a mixture of proteins.

Gaëtan Dugas is free from blame of AIDS Patient Zero

For many years, scientific communities, the press, and the general public blamed Gaëtan Dugas as a "Patient Zero" but recently he was exonerated.

Baltimore system of Classifications of Viruses

All viruses must synthesize positive-strand mRNAs from their genomes, in order to produce proteins and replicate themselves.

Properties of Orthomyxoviruses and Paramyxoviruses

Paramyxoviruses include the most important agents of viral respiratory tract infections notably Respiratory syncytial virus (RSV), Measles, Mumps, and Parainfluenza virus.

Laboratory Diagnosis of Dengue Viral Infection

Detection of IgG and IgM are accessible methods but NS1 antigen detection, genome detection and virus isolation are sensitive methods.

Zika virus: Transmission, Pathogenesis, Symptoms, Lab Diagnosis

Zika virus is an emerging mosquito-borne virus. It is a member of Flavivirus and Aedes mosquitoes act as vector.

Monospot test: Principle, Procedure, Uses

Monospot test is a heterophile antibody test for the rapid screening of infectious mononucleosis caused by Epstein–Barr virus.

Japanese Encephalitis (JE) Virus: Life Cycle, Pathogenesis, Diagnosis

Japanese Encephalitis (JE) virus is a leading cause of vaccine-preventable encephalitis.

Hemagglutination Inhibition Test: Principle, Procedure, Uses

Antibodies against the measles virus neutralize its hemagglutinins, so preventing agglutination of RBCs by these agglutinins.

Ebola Virus: Properties, Disease, and Diagnosis

Why does DNA virus replicate in the nucleus and RNA virus in cytoplasm?

Viral Hemorrhagic Fever (VHFs)

Collection of Upper Respiratory Tract Specimens

Oropharyngeal (OP) and nasopharyngeal (NP) swabs and nasopharyngeal wash/aspirate are the common upper respiratory tract specimens.

Infectious causes of Cancer: Bacteria, Virus and Parasites

Measles virus: Structure, Pathogenesis, Lab Diagnosis

Measles virus is a member of the genus Morbillivirus of the family Paramyxoviridae. Measles is usually a disease of childhood (3-10 years).

Lab Diagnosis of Viral Diseases: Five Approaches

Direct detection of antigen, or gene of virus or isolation of the virus or detection of IgM antibody or four-fold rise in antibody titre.

Henrietta Lacks and Origin of HeLa Cells

What makes some people resistant to HIV infection?

HIV VIRUS, Co receptors, CCR5, CXCR4, CD4 positive T cells,

How does the influenza virus change so fast?

Influenza virus has two ways to change — one slow and one fast. The slow change is known as drift and the fast change is called shift.

Should I worry about bird flu?

Bird flu poses no immediate threat to the average person.

Why does influenza come back year after year?

Influenza virus changes every time it reproduces, generating progeny that are ever so slightly different from the parent.

What is influenza, anyway, and why is it such a big deal?

Category A Infectious Microorganisms

Interpretation of Hepatitis B Serologic Test Results

HBsAg is present early in acute infection, disappears with a resolution of infection, and persists in chronic infection.

Why HBcAg is not detected in Serum?

Hepatitis B core antigen (HBcAg) are expressed by infected hepatocytes only.

Geological Names of Microorganisms and Diseases

Sometimes the name of the microorganisms or diseases are derived from the place of the first isolation of the organism or occurrence of the disease.

Laboratory diagnosis of HIV Infection

Lab diagnosis of HIV is made by measuring anti-HIV antibodies in the serum of the suspected patient by ELISA or RDTS, detecting P24 antigen or via western blot technique.

Continuous Cell Line

Continuous cell line has acquired the ability to proliferate indefinitely through mutations.

Structure of Human Immunodeficiency Virus (HIV)

Poliovirus Vaccine: Salk and Sabin vaccine

Poliomyelitis: Pathogenesis, Clinical Features, Lab Diagnosis

Mumps Virus: Pathogenesis, Clinical Findings, Lab Diagnosis

Mumps is an acute self-limited  viral infection of the children that primarily affects salivary glands.

Influenza (flu) Virus: Classification, Structure, and Diagnosis

Influenza (flu) is caused by influenza viruses, a member of the orthomyxovirus family. There are three types of influenza (flu) viruses: A, B, and C.

Rabies Virus: Structure, Pathogenesis, and Lab Diagnosis

Rabies is a viral disease most often transmitted through the bite of a rabid animal. Rabies virus is a negative-sense, non-segmented, SS RNA virus.

Herpes Simplex Virus (HSV): Structure, Clinical Feature, Lab Diagnosis