VIRUSES
Viruses are submicroscopic particles (0.02 mm to 0.3 mm in size) containing genetic information, in the form of nucleic acid, surrounded by a protein coat. These infectious agents are unable to carry out respiratory or biosynthetic functions and hence depend on a human or animal cell to carry out the metabolic functions necessary for replication. Since viruses invade normal (host) cells, it is difficult to inhibit viral multiplication without affecting the host cell, hence, thus far no effective treatment for viral infections has been discovered. However, viruses are generally eliminated from drinking water during the water disinfection stage. The following section addresses the viruses of interest from a drinking water transmission perspective:
- Hepatitis A
- Hepatitis B
- Hepatitis C
- Hepatitis E
- Norwalk
Hepatitis A. Hepatitis A is one of seven viral infections in the hepatitis group including Hepatitis B, C, D, E, F, and G. Each infection has different characteristics including symptoms, modes of transmission, and disease control. Hepatitis D, F, and G have a low degree of severity, and the fewest number of documented cases. This fact sheet provides information and prevention guidelines on Hepatitis A.
What is Hepatitis A? Hepatitis A is a 27 nanometer (i.e., 1 millionth of a millimeter) virus that targets the liver. Initial symptoms include fever, abdominal pains and nausea which often leads to jaundice. The severity of the symptoms generally increases with age, while some people, especially children may not show any evidence of the illness except through a liver function test.
How May I be Exposed to Hepatitis A? The Hepatitis A virus is present in the feces of infected humans and other nonhuman primates. Peak levels are reached a week or two before symptoms appear. Surface waters such as streams, rivers and lakes may be contaminated with the virus, as well as food and drinking water if handled by an infected person.
What are the Symptoms of Hepatitis A? Abdominal discomfort with fever and/or nausea may occur fifteen to fifty days after swallowing the virus. These symptoms are often followed by jaundice within a few days. If you suspect that you have Hepatitis A, you should see your doctor who will check your bloodstream for antibodies against the virus. An infected person is most likely to pass on the disease before the symptoms appear, and is probably not infectious after the first week of jaundice.
What is the Treatment for Hepatitis A? There is no drug that will cure Hepatitis A, however, your doctor will be able to treat some of the symptoms. Most people recover within 1-2 weeks but should seek medical care as soon as possible. In the event that someone in your household contracts Hepatitis A, you should protect the other members of the household and/or sexual contacts by immunization against the virus within 2 weeks of exposure.
How is Hepatitis A spread? Hepatitis A is contracted only by ingestion of the virus. It is generally transmitted from person to person through the fecal-oral route. Therefore, it is necessary to take precautions as listed below.
How Can I Protect Myself?
1. Know the source of your water: (a) do not drink or swallow water directly from rivers, lakes, streams, pools, or spas, (b) if you travel outside the United States you may want to avoid drinking water that has not been boiled.
2. Always wash your hands with soap and water any time you might have touched human or animal feces, changed diapers, cleaned up feces, or gardened. Always wash your hands before eating.
3. Avoid sex that may involve contact with feces.
4. If you are immunocompromised you should consider additional protective steps such as boiling your drinking water for one minute, which will destroy any viruses in it.
Hepatitis B. Hepatitis B is one of seven viral infections in the hepatitis group including Hepatitis A, C, D, E, F, and G. Each infection has different characteristics including symptoms, modes of transmission, and disease control. Hepatitis D, F, and G are not severe and few cases are reported. This fact sheet provides information and prevention guidelines on Hepatitis B.
What is Hepatitis B? Hepatitis B is a 42-nanometer (i.e., 1 millionth of a millimeter) virus that targets the liver. Initial symptoms include anorexia, abdominal pains and nausea which often leads to jaundice. Fever may also be present. The severity of the infection ranges from asymptomatic to fatal. More than 300 million people are infected with Hepatitis B; one million live in the United States.
How May I Be Exposed to Hepatitis B? The Hepatitis B virus can be located in all body secretions and excretions of man. However, it is only infectious in blood (and serum-derived fluids), saliva, semen , and vaginal fluids.
What Are the Symptoms of Hepatitis B? The incubation period for the virus ranges from 45-180 days with an average of 60-90 days. Hepatitis B may cause flulike symptoms, anorexia, abdominal pains, nausea, dark urine, jaundice, fatigue and fever. The disease can become chronic with potentially fatal conditions in babies who have not been vaccinated. If you suspect that you have Hepatitis B, you should see your doctor who will check your bloodstream for antibodies against the virus. An infected person can pass on the disease many weeks before the symptoms appear, throughout the course of the disease, and also during the carrier state which may persist through life.
What Is the Treatment for Hepatitis B? Currently, Intererfon is the only treatment available for Hepatitis B. However, this treatment only works in less than half the patients who take it. The Hepatitis B vaccination will soon be required of children in California entering day care or kindergarten. In the event that someone in your household contracts Hepatitis B, you should protect the other members and/or sexual contacts by getting immunizations against the virus.
How is Hepatitis B Spread? Hepatitis B is transmitted through contact with infected blood, seminal fluid, vaginal secretions, and sexual contact. Other mechanisms of transmission include: contaminated drug needles, tattoo and body piercing instruments, commonly used toothbrushes, and commonly used razors.
Hepatitis C. Hepatitis C is one of seven viral infections in the hepatitis group including Hepatitis A, B, D, E, F, and G. Each infection has different characteristics including symptoms, modes of transmission, and disease control. Hepatitis D, F, and G lack severity and few cases are reported. This fact sheet provides information and prevention guidelines on Hepatitis C.
What is Hepatitis C? Hepatitis C is a virus that attacks the liver and is approximately 30 to 50 nanometers (i.e., 1 millionth of a millimeter) in diameter. Initial symptoms include anorexia, abdominal pains and nausea which often leads to jaundice. Fever may also be present. The severity of the infection ranges from asymptomatic to fatal. Chronic Hepatitis C may progress to cirrhosis of the liver.
How May I Be Exposed to Hepatitis C? The exposure route of the Hepatitis C virus is via blood and plasma derivatives through the skin. Transfusion recipients, drug users and dialysis patients are at the highest risk of being infected by Hepatitis C.
What are the Symptoms of Hepatitis C? The incubation period for the virus ranges from two weeks to six months. Hepatitis C is related to flulike symptoms, anorexia, abdominal pains, nausea, dark urine, jaundice, fatigue and fever. However, carriers of the Hepatitis C virus may not exhibit any symptoms. If you suspect that you have Hepatitis C, you should see your doctor. Diagnosis occurs through the exclusion of hepatitis A, B, and D viruses and other liver diseases. An infected person can pass on the disease weeks before the first symptoms appear, throughout the course of disease, and also during the carrier state which may persist through life.
What is the Treatment for Hepatitis C? An effective treatment method has not yet been discovered for Hepatitis C. Corticosteroids and acyclovir have been used but with limited results. Chronic carriers of Hepatitis C may find Interferon to be useful. Currently, there is no vaccine available for Hepatitis C.
How is Hepatitis C Spread? Hepatitis C is transmitted through contact with infected blood, contaminated drug needles, syringes, razors, tattoo and body-piercing instruments. It is very rare to contract Hepatitis C through sexual activity.
Hepatitis E. Hepatitis E is one of seven viral infections in the hepatitis group including Hepatitis A, B, C, D, F and G. Each infection has different characteristics including symptoms, modes of transmission, and therefore disease control. Fact Sheets are included for Hepatitis A, B, C, and E. Hepatitis D, F, and G are not of great concern due to their lack of severity, and the small number of documented cases. This fact sheet provides information and prevention guidelines on Hepatitis E.
What is Hepatitis E? Hepatitis E is believed to be caused by a virus or virus family, 32 nm in size, that replicates in the liver. Initial symptoms include fever, abdominal pains and nausea which often leads to jaundice. The severity of the symptoms generally increases with age, while some people, especially children may not show any evidence of the illness except through a liver function test.
Where is Hepatitis E Found? The Hepatitis E virus is present in the feces of infected humans and other nonhuman primates. Surface waters such as streams, rivers and lakes may be contaminated with the virus, as well as food and drinking water if handled by an infected person.
What are the Symptoms for Hepatitis E? Fifteen to sixty-four days after swallowing the virus, you may experience abdominal discomfort with fever and/or nausea. These symptoms are often followed by jaundice within a few days. If you suspect that you have Hepatitis E, you should see your doctor. It is only possible to diagnose Hepatitis E by ruling out the other Hepatitis strains. It is not known when a person is most infectious, but the disease is most likely to be transmitted before symptoms appear, and is probably noninfectious after the first week of jaundice.
What is the Treatment for Hepatitis E? There is no drug that will cure Hepatitis E, however, your doctor will be able to treat some of the symptoms. Most people will recover within 1-2 weeks but should seek medical advice as soon as possible. There are no immunizations for Hepatitis E.
How is Hepatitis E Spread? Hepatitis E is contracted only by ingestion of the virus. It is generally transmitted from person to person through the fecal-oral route and therefore the following precautions should always be taken.
How Can I Protect Myself?
1. Know the source of your water: (a) do not drink or swallow water directly from rivers, lakes, streams, pools, or spas, (b) if you travel outside the United States you may want to avoid drinking water that has not been boiled.
1. Always wash your hands with soap and water any time you might have touched human or animal feces, changed diapers, cleaned up feces, or gardened. Always wash your hands before eating.
3. Avoid sex that may involve contact with feces.
4. If you are immunocompromised you should consider additional protective steps such as boiling your drinking water for one minute, which will destroy any viruses in it.
Norwalk Virus. What is Norwalk Virus? The Norwalk virus represents a mixture of viruses also known as small round structured viruses (SRVSs) or the Norwalk-like family of agents. The agents are usually identified by the location in which an out break occurred. The Norwalk virus itself is a small, 27 to 32 nm virus.
How Can the Norwalk Virus Affect my Health? The incubation period, the time between infection and onset of symptoms, is 24 to 48 hours. The symptoms of Norwalk virus infection include nausea predominantly, with vomiting, non-bloody diarrhea, and abdominal cramps. 25% to 50% of infected persons also have headaches, fever, and chills. The average duration of the illness is 12 to 60 hours.
What is the Treatment for Norwalk Virus Infection? There is no specific treatment for the infection, however, most people recover on their own. In severe cases fluid and electrolyte replacements have to be administered.
How is the Norwalk Virus Spread? Modes of transmission of the Norwalk virus include the ingestion of contaminated water and food (especially shellfish and salads) and other fecal-oral routes, inhalation of aerosols and other airborrne particles, and person-to-person contact. Infectivity may last for as long as two days after symptoms cease.
How Can I Protect Myself? Use hygienic measures applicable to diseases transmitted via the fecal-oral route as listed below:
1. Know the source of your water: (a) do not drink or swallow water directly from rivers, lakes, streams, pools, or spas, (b) if you travel outside the United States you may want to avoid drinking water that has not been boiled.
2. Always wash your hands with soap and water any time you might have touched human or animal feces, changed diapers, cleaned up feces, or gardened. Always wash your hands before eating.
3. Avoid sex that may involve contact with feces.
4. If you are immunocompromised you should consider additional protective steps such as boiling your drinking water for one minute, which will destroy any viruses in it.
Source: http://www.ci.sf.ca.us/puc/wqfs/outbreak.htm