Viral Diseases and Immunity

Cryptosporidium is a genus of apicomplexan protozoans that can cause gastrointestinal illness with diarrhea in humans. Cryptosporidium is the organism most commonly isolated in HIV-positive patients presenting with diarrhea.

HIV tests detect antibodies or antigens produced by the body in response to HIV infection. A positive test result indicates HIV infection, which if left untreated can progress to AIDS (Acquired Immunodeficiency Syndrome). The test identifies the virus, not the advanced disease stage.

First viruses to be used as vectors in gene therapy experiments were retroviruses.
Retroviruses are used for inserting a normal gene into the genome to replace an abnormal disease causing gene. In gene therapy of ADA-SCID or ADA deficiency, haemophilia b, rheumatoid arthritis, etc.

This is a major portal of entry, though not the only one. The chemokine receptors CXCR4 and CCR5 are also major portals of entry and reduce the CD4 positive helper T-cell numbers dramatically.

CMV is an example of herpesviruses. These are all large DNA viruses of which CMV is the largest; which is also known as human herpesvirus-5 (HHV-5).

VZV lies dormant in sensory nerve ganglia (near the base of the nerves) for decades and re-emerges to cause shingles.

CXCR4 is a chemokine receptor which HIV utilizes as a coreceptor for entry into naive CD4+ T-cells and mature dendritic cells. Another chemokine receptor, CCR5, is used particularly for entry of HIV into immature dendritic cells, macrophages and activated effector or memory CD4+ T-cells.

This is the correct option. Genital warts and chlamydiasis are completely curable if detected early and treated properly.

Viruses have completely dependent metabolism because they are obligate parasites - they cannot reproduce or carry out metabolic processes on their own and must hijack host cellular machinery. They have no independent metabolic capabilities and rely entirely on host cells for energy, protein synthesis, and replication. Viruses are essentially genetic material wrapped in protein, lacking their own metabolic systems.

Orthomyxoviruses (influenza A, B, and C viruses) are enveloped viruses that contain single-stranded RNA in a helical array of nucleoprotein. Inserted in the lipid envelop are two glycoproteins- the hemagglutinin (HA) and the neuraminidase (NA).

Respiratory syncytial virus (RSV) was first isolated in 1956 by Morris and co-workers who named it “chimpanzee coryza agent”. Shortly thereafter, Chanock and co-workers confirmed that the agent was able to cause respiratory illness in humans. Respiratory syncytial virus measures from 121 to 300 nm. It has an RNA genome, and like all members of the paramyxovirus family, the envelop exhibits spokes of glycoprotein.

All are the members of the family Flaviviridae .

Adenoviruses are medium-sized (90-100 nm), nonenveloped (without an outer lipid bilayer) icosahedral viruses composed of a nucleocapsid and a double-stranded linear DNA genome.

African swine fever virus (ASFV) is a large double-stranded DNA virus which replicates in the cytoplasm of infected cells and is the only member of the Asfarviridae family. In common with other viral haemorrhagic fevers, the main target cells for replication are those of monocyte, macrophage lineage.

Human Immuno Deficiency Virus