Virus Resources

Forensic Nurse Guide: Viruses

Viruses are a ubiquitous part of life, virtually included in every facet of the ecosystem. Viruses affect all organisms, from animals to plants to bacteria, but are unique in that they can only exist and replicate with a living organism as its host. In humans, virus can range from the common cold, to sexually transmitted diseases, to HIV/AIDS. And while some viruses can be wiped out by vaccine, there are many others that continually show resistance. Understanding viral diseases and correlating cures prove to be a consistent battle in medicine, as viruses continue to evolve.

The following resource contains information regarding some of the most common and well-known viruses affecting human health today. By no means is this a comprehensive list, as the list of identified viruses range in the thousands. However, this resource seeks to provide insight and information regarding the diseases and conditions that affect millions of people a year.

Viruses

Viruses can be spread through a variety of ways, from insect to insect transmission, to sneezing and coughing, from ingestion, or through infected blood (cuts and STDs). Once a virus infects a host, it can rapidly replicate and spread throughout the body. Unlike bacterial infections that can be treated with antibiotics, viruses cannot be eliminated as easily due to its metabolic pathways. The best form of protection against viruses is a preventative vaccine (examples: polio, measles, mumps), although, these vaccines can prove to be ineffective if a virus has evolved into different strands. Antiviral drugs are also employed to fight viruses, but does not eliminate the pathogen and only inhibits it.

Dengue Fever

Dengue comes from one of four virus serotypes and of the genus, Flavivirus. The infection provides immunity to only one of that serotype for life. The Dengue fever’s common symptoms include fever, headache, skin rash, and muscle and joint pains, The virus is transmitted through mosquitoes from the Aedus genus. A vaccine for dengue is not currently available, but research is being conducted, so that it may be available to the public in 5 to 10 years.

Encephalitis, Arbovirus

Arboviruses are transmitted by arthropod vectors that bite and enter the circulatory system. Though encephalitis has a global distribution, the four main viral agents in the United States are St. Louis encephalitis (SLE), western equine encephalitis (WEE), eastern equine encephalitis (EEE) and La Crosse (LAC) encephalitis, in which are transferred by mosquitoes. These symptoms can include fever, confusion, headache, drowsiness and fatigue. Hallucinations, seizures, and memory problems can also occur in the more serious cases.

West Nile Fever

West Nile can be a very serious and sometimes fatal disease that is transmitted by infected mosquitoes in tropical climate. In humans, many of those who are infected go asymptomatic, then experience flu-like symptoms with rash, nausea, vomiting and diarrhea. In severe cases, West Nile can become encephalitis, affecting the circulatory system.

Rift Valley Fever

This type of virus affects mainly livestock, but can be passed to humans, by way of mosquitoes, causing fever. The symptoms in humans can differ from that of livestock, including no symptoms at all, or headaches, fever and liver abnormalities. Thankfully, only about 1% of infected humans actually die from the diseases whereas the levels of fatality among livestock are greater.

Yellow Fever

The virus is spread by female mosquitoes and usually found in tropical areas such as South America and Africa. General symptoms include nausea and fever, but sometimes a toxic phase follows where the liver can be damaged, ultimately leading to death. Fortunately, there is an effective and safe vaccine provided for those to guard again the fever. Some countries will even require the vaccination for those whom are traveling into the country.

Subacute Sclerosing Panencephalitis

This is a very rare disease that affects mostly children and young adults. SSPE is caused by a persistent infection from the measles virus, which is immune resistant. As of today, there is no cure for the condition, but can be maintained if treated early. Symptoms include a history of primary measles typically before 2 years of age, followed by gradual psychoneurological deterioration, seizures, coma, personality changes, and photosensitivity.

Adenoviridae Infections

Adenoviruses are DNA virus infections with 55 serotypes in humans that are responsible for the upper respiratory infections in 5-10% of children and adults. Transmission typically occurs via respiratory droplets because they have prolonged survival outside of the body and water. There used to be a vaccine to fight against two serotypes for the US military, but are no longer available.

Herpesviridae Infections

This DNA virus, part of a large family, causes diseases in both humans and animals. These infections cause lesions on the mucous membranes and in the skin. There are eight different viruses in the family that causes the disease to humans: HHV-1 through 6. The animal infections include Macauqe monkeys and mice.

Chickenpox

Often associated as a childhood disease, this illness is extremely contagious that typically starts with a spreading skin rash, producing raw pockmarks that actually heal without any scarring. This airborne disease is easily spread by the sneezing or coughing between those infected or even with contact to the rash on the skin. The rash appears after one to five days after being infected followed by the contagious period. Though there is not an actual cure for chickenpox, there are treatments available for relieving the symptoms, and most people only suffer once in lifetime.

Epstein-Barr Virus Infections

EBV, also known as HHV-4, is most common in humans in the form of mononucleosis. It is also associated with certain forms of cancer in rare cases. People who become infected with EBV typically gain adaptive immunity and about 90-95% of adults, and half of all 5 year olds have signs of previous infection. An EBV test is done by a blood sample in which abnormalities would be examined.

Infectious Mononucleosis

This disease, popularly known as the kissing disease, or mono, can have no symptoms or flu-like ones in the beginning. It is most common in young adults and adolescents and contains symptoms such as sore throat, fatigue and fever. Rest is most often prescribed as treatment, while Ibuprofen can be used to reduce pains and fever.

Herpes Simplex

Herpes is a highly contagious simplex virus that can lead to cold sores around the mouth. Type 2 is typically sexually transmitted, leading to genital herpes that cause pain and blisters around the infected genital area. Both of these can be transferred by direct contact. Herpes can often go asymptomatic, and thus an infected person can spread the disease unknowingly. There is no cure for herpes, but medication is prescribed to prevent and treat flare ups.

Herpes Zoster

Also known as shingles, herpes zoster is an outbreak of blisters or rashes on the skin caused by the same virus that leads to chickenpox, the varicella-zoster virus. Tingling or burning pains, as well as itchiness or numbness can be the first signs of shingles. Antiviral drugs can be used to reduce the duration and severity of the attack. Shingles do not come from an outside source; it actually comes from a hidden virus inside the person’s body.

Warts

A viral infection causes skin growths on the top layer of the skin that are typically non-cancerous. Human papillomavirus produces warts caused by viruses, and they typically feel rough to the touch and are skin-colored. Three types of warts that occur the most are common warts, foot/plantar warts, and flat warts. The risk of transmitting flat, hand or foot warts from another person is a relatively small number.

Condyloma Acuminata

Also known as genital or venereal warts, condyloma is caused by the virus HPV. They cause small growths on the mucous membranes and on the skin with infections on the genital and anal regions. HPV infections are very common among women in college where only 1-2% actually had visible warts.

Erythema Infectiosum

This disease also known as fifth disease, referring to a rash typically found on the cheeks of infected children (sometimes named “slapped cheek disease”). The rash typically lasts a few days and may itch, but is usually not infectious once the rash appears. Adults or teenagers may experience a self-limited arthritis where pains and swelling of the joints. The disease is spread mostly by respiratory secretions, but also can be transferred by contact with infected blood.

Ecthyma, Contagious

This infectious dermatitis condition typically affects sheep and goat mouths. Other reported cases have been found in dogs as well as humans. Humans can contract this infection, also known as Orf, from direct contact with infected animals carrying the virus. Infected areas tend to be the finger, arm, hand or face.

Molluscum Contagiosum

Molluscum is a skin infection caused by a virus that creates small bumps and lesions on the skin with a white core that is hard to the touch. The bumps are skin colored, but looks waxy and doesn’t typically itch or hurt. It is spread by direct contact with the skin and often through sexual activity that usually appears on the face or groin areas. The lesions are usually treated the same way as warts, but they often reappear and have to be retreated.

Smallpox

Smallpox is very serious and contagious virus, with no treatment but a preventative vaccine. Transmission occurs with prolonged face-to-face contact as well as bodily fluids. Symptoms usually include head and body aches, high fever, and vomiting. The rash then follows as raised bumps with pus-filled blisters that eventually crust and fall off, leaving scars.

Lassa Fever

This illness is a viral hemorrhagic and an often fatal fever associated with RNA viruses. This condition typically occurs more in the drier seasons as opposed to rainy season. The victims often “export” the disease from Africa to other countries. It usually transmitted to humans through the bloodstream, respiratory tract, lymph vessels or digestive tract. Because of the viral replication, the reticuloendothelial cells lead to capillary lesions.

Hantavirus Infections

Hantaviruses are part of the bunyaviridae family and are negative sense RNA viruses. Rodents and their urine, saliva, bites, or even contact with their waste products can infect humans with this virus. It takes about two to four weeks before symptoms actually occur in five phases: febrile, hypotensive, oliguric, diuretic, and convalescent phase. There is an unknown antiviral treatment, but it is possible with natural recovery.

Measles

Measles are typically defined by the following symptoms: a rash that sticks around for 3 or more days, a temperature great than 101F, and cough, conjunctivitis, and coryza. Vaccination has been available since 1963 in the U.S., with a decrease of the disease as the ages shift from children to young adults. Thought it is widely available, not everyone is openly willing to receive it due to debunked autism concerns or religious reasons.

Respiratory Syncytial Virus Infections

RSV is a syncytial viral infection similar to a really bad cold with the same symptoms. Because of that the similarities, it is also very common and contagious. It is caused by RSV attacking the nose, lungs, eyes, and throat and spreading like a cold. Because of so many different types of RSV, many people will suffer multiple cases in a lifetime.

Mumps

Also known as epidemic parotitis, mumps may cause salivary glands swelling or rashes. Fever and headaches are also typical symptoms of mumps. The condition can be spread easily between persons through contact by the exchange of saliva such as the sneezing or coughing from an infected person.

  • The basics about mumps from KidsHealth.
  • Q&A about mumps from MedicineNet.com.

Rabies

This viral disease leads to brain inflammation in warm-blooded animals. It is most commonly spread by a bite from an animal that is infected and can be fatal if not treated. Rabies attack the central nervous system, therefore infecting the brain functions. Symptoms include fever, weakness, and headaches.

Influenza

Considered one the most common viral diseases, the flu affects hundreds of millions of people a year. The symptoms of human flu typically are cough, sore throat, fever, conjunctivitis and muscle aches. These flu epidemics occur during flu season and are typically not deadly except to those that are very young or old. They are also easily transmitted through coughs or sneezes by the germs in the air.

Coxsackievirus Infections

This virus lives in the human digestive tract and can be easily spread between persons by way of contaminated surfaces and unclean hands. Usually, the outbreaks occur during the fall and summer in the cooler climate areas, but occurs year-round in the tropical areas. About half of the infected children experience no symptoms but then encounter headache, fever or muscle aches.

HIV Infections

Human immunodeficiency virus is a condition that causes the immune system to completely fail, leading to AIDS. This also allows for cancers or infections to grow, ultimately leading to death. Infection is transmitted through bodily fluids usually by infected needles, unsafe sex, infected mother to her baby, or breast milk. HIV is a very serious condition and has killed over 25 million people since 1981.