VIRAL DIARRHEAMIC 450 - LAP

What is diarrhea?

Diarrhea is frequent, loose, and watery bowel movements. also called {stools}

body wastes passed through the rectum and anus.

Stools contain what is left after your digestive system absorbs nutrients and fluids from what you eat and drink.

If your body does not absorb the fluids, or if your digestive system produces extra fluids, stools will be loose and watery

Loose stools contain more water, salts, and minerals and weigh more than solid stools.

Acute diarrhea:-Diarrhea that lasts a short time is called acute diarrhea. Acute diarrhea is a common problem and usually lasts only 1 or 2 days, but it may last longer.

Chronic diarrhea :- Diarrhea that lasts for at least 4 weeks is called chronic diarrhea. Chronic diarrhea symptoms may be continual or they may come and go

The type of diarrhea-:

What other symptoms might I have with diarrhea?

In addition to passing frequent, loose stools, other possible symptoms includeo cramps or pain in the abdomen

the area between the chest and hips

o an urgent need to use the bathroom

o loss of bowel control

You may feel sick to your stomach or become dehydrated. If a virus is the cause of your diarrhea, you may have fever and chills and bloody stools.

Dehydration-:

Being dehydrated means your body does not have enough fluid to work properly.

Every time you have a bowel movement, you lose fluids.

Diarrhea causes you to lose even more fluids.

You also lose salts and minerals such as sodium, chloride, and potassium.

These salts and minerals affect the amount of water that stays in your body.

Dehydration can be serious, especially for children, older adults, and people with weakened immune systems.

Signs of dehydration in adults are-:

being thirsty urinating less often

than usual having dark-colored

urine having dry skin feeling tired feeling dizzy or

fainting

Signs of dehydration in babies and :young children are

having a dry mouth and tongue

crying without tears having no wet diapers for 3

hours or more having sunken eyes, cheeks,

or soft spot in the skull having a high fever being more cranky or drowsy

than usual  

• bacteria\ from contaminated food or water•- viruses\ that cause illnesses such as the flu•- parasites\, which are tiny organisms found in contaminated food or water•- medicines such as antibiotics•- problems digesting certain foods•- diseases that affect the stomach, small intestine, or colon, such as Crohn’s disease• problems with how the colon functions, caused by disorders such as irritable bowel syndrome

Causes of diarrhea include

the type of virus who causes diarrhea :-

- Rotavirus

- Adenovirus

Rotavirus

History: In 1974, Thomas Henry suggested the name rotavirus after observing that, when viewed through an electron microscope, a rotavirus particle looks like a wheel (rota in Latin) the name was officially recognised by the International Committee on Taxonomy of Viruses four years later. In 1976, related viruses were described in several other species of animals.These viruses, all causing acute gastroenteritis, were recognised as a collective pathogen affecting humans and animals worldwide. Rotavirus serotypes were first described in 1980, and in the following year, rotavirus from humans was first grown in cell cultures derived from monkey kidneys, by adding trypsin (an enzyme found in the duodenum of mammals and now known to be essential for rotavirus to replicate) to the culture medium.The ability to grow rotavirus in culture accelerated the pace of research

rotavirus spread: Rotavirus infection is highly contagious. The primary mode

of transmission of rotavirus is the passage of the virus in stool to the mouth of another child. This is known as a fecal-oral route of transmission. Children can transmit the virus when they forget to wash their hands before eating or after using the toilet. Touching a surface that has been contaminated with rotavirus and then touching the mouth area can result in infection.

There also have been cases of low levels of rotavirus in respiratory-tract secretions and other body fluids. Because the virus is stable (remains infective) in the environment, transmission can occur through ingestion of contaminated water or food and contact with contaminated surfaces. Rotavirus can survive for days on hard and dry surfaces, and it can live for hours on human hands.

Types of rotavirus: There are five species of rotavirus,

referred to as A, B, C, D and E. primarily infected by species A, B and C,

most commonly by species A. All five species cause disease in other animals.

Structure:

The genome of rotavirus consists of 11 unique double helix molecules of RNA which are 18,555 nucleotides in total. Each helix, or segment, is a gene, numbered 1 to 11 by decreasing size. Each gene codes for one protein, except genes 9 and 11, which each code for two. The RNA is surrounded by a three-layered icosahedral protein capsid. Viral particles are up to 76.5 nm in diameter and are not enveloped

When a person becomes infected with rotavirus, it begins to multiply within the small intestine. After approximately two days, rotavirus symptoms can begin. This period between the rotavirus transmission and the start of symptoms is called the "rotavirus incubation period.“

Not all people who are infected with the virus will develop symptoms. If symptoms do occur, the illness tends to begin suddenly.

Common rotavirus symptoms include: 

Vomiting

Upset stomach

Watery diarrhea

Severe dehydration

High fever (greater than 102.2°F)

Loss of appetite

Mucus in stool.  

Signs and Symptoms:

The watery diarrhea can be mild to severe and generally will last for three to nine days. Severe diarrhea can lead to a dangerous depletion of body fluids called dehydration, which can result in death if untreated. Virtually all children become infected with rotavirus in the first three to five years of life, but severe diarrhea and dehydration occur mainly among children aged 3 to 35 months.

Diagnosis

Diagnosis of infection with rotavirus normally follows diagnosis of gastroenteritis as the cause of severe diarrhoea. Most children admitted to hospital with gastroenteritis are tested for rotavirus A.

Specific diagnosis of infection with rotavirus A is made by finding the virus in the child's stool by enzyme immunoassay . There are several licensed test kits on the market which are sensitive, specific and detect all serotypes of rotavirus A.

Other methods, electron microscopy and polyacrylamide gel electrophoresis , are used in research laboratories. Reverse transcription-polymerase chain reaction (RT-PCR) can detect and identify all species and serotypes of human rotavirus.

Vaccine

The vaccine protects against rotavirus, the leading cause of severe diarrhea in babies and young children around the world – and formerly in the United States, before the vaccine came along. The severe diarrhea caused by this virus is often accompanied by fever, vomiting, dehydration, and sometimes death. It's extremely contagious, spreading easily through ordinary person-to-person contact.

There are two rotavirus vaccines available in Canada. They are available under these brand names: RotaTeq (Merck Frosst Canada) and Rotarix (GlaxoSmithKline).

TreatmentTreatment of acute rotavirus infection is nonspecific

and involves management of symptoms and, most importantly, maintenance of hydration. If untreated, children can die from the resulting severe dehydration. Depending on the severity of diarrhoea, treatment consists of oral rehydration, during which the child is given extra water to drink that contains small amounts of salt and sugar. Some infections are serious enough to warrant hospitalisation where fluids are given by intravenous drip or nasogastric tube, and the child's electrolytes and blood sugar are monitored

Adenovirus

Adenoviruses were first discovered in 1953 by Wallace Rowe and his colleagues. They were isolated from adenoid tissue cell culture, hence the

family name of Adenoviridae.In 1962, John Trentin and his colleagues showed that human adenovirus type 12 causes cancer in baby hamsters in a laboratory setting. This was the first

demonstration of oncogenic activity by a human virus. Since then, adenoviruses have been suspected in inducing human cancer but have yet to

be strongly linked to it. Experiments involving adenoviruses, which are easy to culture and work

with, have made important contributions to eukaryotic molecular biology.

History

Adenoviruses — a group of viruses that infect the membranes (tissue linings) of the respiratory tract, the eyes, the intestines, and the urinary tract — account for about 10% of acute respiratory infections in kids

and are a frequent cause of diarrhea. 

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. There are 57

described serotypes in humans, which are responsible for 5–10% of upper respiratory infections in children,

and many infections in adults as well.Viruses of the family Adenoviridae infect various

species of vertebrates, including humans.

Structure

1- Adenoviruses are very contagious and local outbreaks are common (for example, at summer camps, playgrounds, schools, or public swimming pools) 2- Respiratory Transmission: usually through a cough or a sneeze, adenoviruses can infect the mucosa of the eyes or respiratory tract through aerosolized viral particles or through mucous droplets. 3- Direct Contact: adenoviruses are very stable in the environment and can survive chemical and pH disturbances. Therefore the virus can be transmitted by touching a contaminated surface and then touching the mucosa or the eyes or mouth (note: this is also semi-respiratory transmission since it infects the respiratory mucosa).

4- Fecal-Oral: usually through contaminated food or water, or through poor personal hygiene (i.e. do not wash hands). 5- Water-borne: adenoviruses are often transmitted in swimming pools, especially when insufficient chlorine has been used.

 

Transmission

To diagnose adenoviral infection, the virus is first isolated from body fluids or secretions (via eye swabs, throat swabs, urine, feces, leukocytes, or cerebrospinal fluid.) These secretions are then examined under the microscope to look for characteristic cytopathic effects .More specific diagnosis is made from antigen detecting tests (such as ELISA) or from a polymerase chain reaction (PCR) .

 Diagnosis

There is no vaccine to prevent adenovirus infection, nor is there

a cure for these viruses.

Vaccine

Signs and Symptoms 

Febrile respiratory disease which is an infection with fever of the respiratory

tract, is the most common result of adenoviral infection in kids. The illness often appears flu-like

and can include inflammation of the pharynx, or sore throat, inflammation of nasal membranes, or a

congested, runny nose, cough, and swollen lymph nodes .

Gastroenteritis is an inflammation of the stomach and

the small and large intestines. Symptoms include watery diarrhea,

vomiting, headache, fever, and abdominal cramps.

Urinary tract infections can cause frequent urination, burning, pain, and

blood in the urine.

Eye InfectionsConjunctivitis (or pinkeye) is a

mild inflammation of the conjunctiva. Symptoms include

red eyes, discharge, tearing, and the feeling that there's something

in the eye

There is no effective treatment for adenovirus infections. Ribavirin or other antiviral medications are sometimes used, but they do not usually have significant effects. Treatments are generally targeted at the symptoms of adenovirus, and include oral rehydration, sleep

and rest, warm compresses, drugs [acetaminophen (Tylenol), decongestants, non-steroidal anti-inflammatory drugs, but rarely aspirin (due to the risk of Reye Syndrome)]. Intravenous antiviral drugs (such as ribavirin) can be used to treat severe diseases. A

new vaccine made by Barr Laboratories is expected to be released in 2008

Treatment

PreventionSince adenoviruses are transmitted in a variety of different ways,

there are a wide range of preventative measures that can be taken to reduce the likelihood of infection. These include:

Respiratory • Cover mouth and nose while sneezing

• Avoid touching eyes, nose, or other respiratory mucosa

Fecal-Oral and Direct Contact • Frequent hand-washing and other personal hygiene measures • Clean potentially contaminated surfaces (table tops, counters,

toys, drawer handles, etc.)

Water-borne • Maintain chlorine levels in pools

• Sterilize water

Nosocomial and Iatrogenic • Sterilization of hospital equipment

• Wear masks, gloves, and other protective clothing when interacting with a patient with adenovirus infection

General Prevention • Avoid conscious exposure to people known to have an adeno

•Jmeelh Al-swayed •Sarah Al-Ghouraibi•Elaf Al-shdokhi•Hadeel Al-Dosari•Alanoud Al-Dossary