Viral Diseases

HIV

This virus target the immune system, such as dendritic cells, macrophages and CD4+ T cells, which not only makes a person immunocompromised but helps spread the infection to other organs.

HIV Virus Type

Retrovirus

HIV Enzymes

Reverse Transcriptase, integrase

Reverse Transcriptase

makes a lot of errors when copying the RNA into DNA so the proteins on the virus surface can change frequently and it can become resistant to antiviral compounds fast. 

HIV infected people often develop the malignancy called ______, caused by the Human herpesvirus 8 (HHV-8)

Kaposi's sarcoma

The transmission of the HIV is by…

sexual contact, blood, dirty needles, and mother to child during pregnancy, childbirth, or breastfeeding

Measles (rebeola)

Droplet/Respiratory Spread. Highly contagious. 

Severe complications can include acute measles encephalitis and the rare, progressive neurological disorder subacute sclerosing panencephalitis (SSPE).

Measles Vaccine

MMR Vaccine

Diagnostic Indicator of Measles (these appear before the characteristic measles rash develops) 

Koplik’s spots

Rubella (german measles)

macular rash resembling measles but less extensive. Can cross the placenta.

How is rubella spread?

Droplet/Respiratory Spread

Rubella Vaccine

MMR Vaccine

Varicella-Zoster

Herpesvirus (HHV-3) that causes chickenpox and can cause complications such as damage to blood vessels and, when aspirin is used during the infection, possibility Reye’s syndrome. 

Resides in ganglia of the head and neck in its latent form, it can be activated and cause Shingles.

Varicella=Zoster Vaccine

attenuated virus vaccine that is available to protect against chickenpox and a stronger version of this vaccine is given to protect against Shingles.

Smallpox

The one success story of ridding the human population of a dreaded virus. There are no animal host reservoirs.  A successful global vaccination program was essential for this to happen. 

A similar disease to smallpox but less severe caused by __________ has become a growing health concern.

Monkey Pox

__________ is in the same genus as the smallpox virus and the smallpox vaccine has a protective effect in disease spread.

Monkey Pox

Herpes Simplex Virus (HSV)

predominately found in cold sores and predominately found in genital herpes.  

__________ is a latent virus that resides in ganglia and it can lead to more serious complications such as encephalitis. Another complication from an active infection is neonatal herpes usually resulted from transmission during childbirth. The virus can be shed even when there is no lesion present.

HSV

Human Papillomavirus (HPV)

 There are over 200 types of this virus, and most cause common skin warts, and a few types cause genital warts, and about 14 types (HPV-16 and HPV-18) are related to cervical cancer, and are also associated with cancer of the vulva, vagina, penis, anus, and oropharynx. 

HPV Vaccine

Gardasil (does not treat an existing HPV infection, HPV-related disease, or cancer)

How many strains of HPV does Gardasil prevent?

9

Epstein- Barr Virus (EBV)

This herpesvirus (HHV-4) causes infectious mononucleosis ("mono") and targets the B cells of the immune system. It also remains latent in the B-cell after recovery of the initial infection. 

__________ can lead to complications in immunocompromised people, and it can cause Burkitt's Lymphoma as well as nasopharyngeal carcinoma.

EBV

Cytomegalovirus (CMV)

Approximately 80% of adults are carriers of this human herpes virus-5 (HHV-5).  This virus can cross the placenta and cause severe damage to the fetus (cytomegalic inclusion disease, CID).

________ is also a problem in immunocompromised individuals and patients receiving a transplant since they need to take drugs to suppress their immune system and can't fight off this virus as easily as a healthy person.

CMV

Rhinovirus

Most common cause of a cold.  So many different strains of this virus make it impossible to produce an effective vaccine. Coronaviruses are also a common cause of a cold.

Influenza virus

Is composed of 8 fragments of RNA which codes for the viral proteins.  Hemagglutinin (HA) and Neuraminidase (NA) are required for the virus to be infectious. Gradual accumulation of mutations in the genes coding for these proteins result in different viral strains.  

Gradual accumulation of mutations in the genes coding for these proteins result in different viral strains.  These continuous changes are referred to as __________ and it is the reason why every year there are different viruses that make up the influenza vaccine. 

Antigenic Drift

Since the viral RNA is on different fragments, it is known that if 2 different virus strains infect a host cell simultaneously, there is a chance for gene reassortment of these different influenza viral RNA fragments which also results in new viral strains.  This significant change is called _________ and is why the "Bird Flu" (avian influenza) is a concern to us since it is known that in cases where people become infected with the Bird Flu there is a high mortality rate with it. 

Antigenic Shift

Flu Virus Vaccine

The vaccine is produced every year with a few different strains that are most predominant that year. It is made in the embryonated chicken eggs, but this is very inefficient which is why there have been vaccine shortages.  Currently cell culture-based methods have become an important advancement in influenza vaccine production.

Severe Acute Respiratory Syndrome (SARS)

caused by a coronavirus, SARS-CoV-1. The disease has a high mortality rate, and the first outbreak was in China in 2002. The source of SARS-CoV-1 is believed to be bats, with the virus likely being transmitted to humans through intermediate hosts, such as palm civets. The virus is spread by close contact with infected people, and it is monitored by the World Health Organization (WHO) as an emerging virus. Since 2004, no known cases of SARS due to quarantining people sick with the virus.

__________ is an enveloped virus with an unsegmented single-stranded positive-sense RNA (+ss RNA). The high mutation rate when this RNA virus replicates its RNA causes new strains of the virus to evade antibodies made to a previous strain. That is why vaccine formulations sometimes need to be updated to target newly emerging variants, and booster shots are often recommended to maintain protection.

Coronavirus

Respiratory Syncytial Virus (RSV)

It causes the most common lower respiratory infection in infants.  The virus is named for its characteristic of causing cell fusion when grown in cell culture. Hospital workers need to be careful not to spread this virus in the nursery wards. 

Mumps

Humans are the only host of the virus. If it occurs in adults or leads to severe inflammation, male sterility, meningitis, inflammation of the ovaries, etc.

Mumps Vaccine

MMR Vaccine

Rotavirus

A common cause of viral gastroenteritis among infants and young children.  Hospital workers must be careful not to spread the virus in the children's ward. There is a vaccine to it.  In developing countries, there is a high mortality rate associated with this virus since children do not receive fluids lost from diarrhea.

Noroviruses

 A group of viruses like the first identified Norwalk virus. They are the most common cause of viral gastroenteritis affecting all age groups. They are transmitted by the fecal–oral route and even aerosols from vomiting. The virus is highly contagious can remain on surfaces for a long time.

_________ ___ is caused by a DNA virus and the other two are RNA viruses.

Hepatitis B

________ is spread by the fecal - oral route, and there is a vaccine to it.  

Hepatitis A

_______ is spread mainly through blood and sexual contact.  A person can carry this virus in their body for many years after recovery which may lead to liver disease. There is a vaccine which all health care workers should receive. This virus is implicated in some cases of liver cancer.

Hepatitis B

________ is spread through blood products.  It can become a chronic infection in some people and has been implicated in some cases of liver cancer and liver cirrhosis. There isn't a vaccine. The risk of transmission through sexual contact is generally considered low.

Hepatitis C

Polio

There are three serotypes. This virus enters the body through the mouth, typically via the fecal-oral route. The complication caused by the poliovirus is complete or partial paralysis. The WHO has attempted to get all countries to participate in a vaccination campaign to eliminate the virus from the planet but so far it has not met with the same success that smallpox vaccination has.   

Polio Virus Vaccine

There are two forms of the vaccine (Salk– Inactivated Vaccine and Sabin–Oral Vaccine). Sabin vaccine is no longer licensed or available in the U.S. for routine use. Since everyone in this country is vaccinated we would most likely only see cases of it in someone not vaccinated coming from another country.

Rabies Virus

almost always results in fatal encephalitis. This virus is found in many mammals and spread to people from infected animals usually through bites and scratches. Exposure to infected saliva through unnoticed bat bites or contact with mucous membranes also contributes to transmission.  

West Nile Virus

Is transmitted by mosquitos and has spread across the country in the short time that it was introduced in this country.  It can be thought of as an emerging disease and will be hard to control since birds are a reservoir for the virus.

Some other mosquitoes-borne encephalitis. __________ cause inflammation of the brain. These viruses can be thought of as re-emerging viruses and birds are reservoir for some of these viruses. Mosquitoes pass these viruses on to humans and horses.

Eastern Equine, Western Equine, and St. Louis Encephalitis Viruses 

_________ transmitted primarily by mosquitoes. The virus can be also transmitted sexually, mother to fetus during pregnancy and through blood transfusions. The major complication is microcephaly in the infant when the mother contracts the disease during pregnancy and the virus cross the placenta.  

Zika virus

______ are infections that can naturally spread from animals to humans. 

zoonoses