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

Specific diagnosis of infection with 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 . Other methods, such as electron microscopy and PCR, are used in research laboratories. Reverse transcription-polymerase chain reaction (RT-PCR) can detect and identify all species and serotypes of human rotavirus.

A determination of whether or not the person has dehydration is an important part of the assessment, with dehydration typically divided into mild (3–5%), moderate (6–9%), and severe (≥10%) cases. In children, the most accurate signs of moderate or severe dehydration are a prolonged capillary refill, poor skin turgor, and abnormal breathing. Other useful findings (when used in combination) include sunken eyes, decreased activity, a lack of tears, and a dry mouth. A normal urinary output and oral fluid intake is reassuring. Laboratory testing is of little clinical benefit in determining the degree of dehydration. Thus the use of urine testing or ultrasounds is generally not needed.

Gastroenteritis is typically diagnosed clinically, based on a person's signs and symptoms. Determining the exact cause is usually not needed as it does not alter management of the condition.

However, stool cultures should be performed in those with blood in the stool, those who might have been exposed to food poisoning, and those who have recently traveled to the developing world. It may also be appropriate in children young than 5, old people, and those with poor immune function. Diagnostic testing may also be done for surveillance. As hypoglycemia occurs in approximately 10% of infants and young children, measuring serum glucose in this population is recommended. Electrolytes and kidney function should also be checked when there is a concern about severe dehydration.

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

Specific diagnosis of infection with 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 . Other methods, such as electron microscopy and PCR (polymerase chain reaction), are used in research laboratories. Reverse transcription-polymerase chain reaction (RT-PCR) can detect and identify all species and serotypes of human rotavirus.

Because improved sanitation does not decrease the prevalence of rotaviral disease, and the rate of hospitalisations remains high, despite the use of oral rehydrating medicines, the primary public health intervention is vaccination. Two rotavirus vaccines against Rotavirus A infection are safe and effective in children: Rotarix by GlaxoSmithKline and RotaTeq by Merck. Both are taken orally and contain attenuated live virus.

Rotavirus vaccines are licensed in more than 100 countries, but only 17 countries have introduced routine rotavirus vaccination. Following the introduction of routine rotavirus vaccination in the US in 2006, the health burden of rotavirus gastroenteritis "rapidly and dramatically reduced" despite lower coverage levels compared to other routine infant immunizations. Clinical trials of the Rotarix rotavirus vaccine in South Africa and Malawi, found that the vaccine significantly reduced severe diarrhoea episodes caused by rotavirus, and that the infection was preventable by vaccination. A 2012 Cochrane review of 41 clinical trials that included 186,263 participants concluded Rotarix and RotaTeq are effective vaccines. Additional rotavirus vaccines are under development. The World Health Organization(WHO) recommends that rotavirus vaccine be included in all national immunisation programmes. The incidence and severity of rotavirus infections has declined significantly in countries that have acted on this recommendation.

The Rotavirus Vaccine Program is a collaboration between PATH, the (WHO), and the U.S. Centers for Disease Control and Prevention, and is funded by the GAVI Alliance. The Program aims to reduce child morbidity and mortality from diarrhoeal disease by making a vaccine against rotavirus available for use in developing countries.

Rotavirus is highly contagious and cannot be treated with antibiotics or other drugs. Because improved sanitation does not decrease the prevalence of rotaviral disease, and the rate of hospitalisations remains high despite the use of oral rehydrating medicines, the primary public health intervention is vaccination. In 1998, a rotavirus vaccine was licensed for use in the United States. Clinical trials in the United States, Finland, and Venezuela had found it to be 80 to 100% effective at preventing severe diarrhoea caused by rotavirus A, and researchers had detected no statistically significant serious adverse effects. The manufacturer, however, withdrew it from the market in 1999, after it was discovered that the vaccine may have contributed to an increased risk for intussusception, a type of bowel obstruction, in one of every 12,000 vaccinated infants. The experience provoked intense debate about the relative risks and benefits of a rotavirus vaccine.

In 2006, two new vaccines against infection were shown to be safe and effective in children, and in 2009, the WHO recommended that rotavirus vaccine be included in all national immunisation programmes.

The incidence and severity of rotavirus infections has declined significantly in countries that have acted on this recommendation. A 2014 review of available clinical trial data from countries routinely using rotavirus vaccines in their national immunisation programs found that rotavirus vaccines have reduced rotavirus hospitalisations by 49–92 percent and all cause diarrhoea hospitalisations by 17–55 percent. In Mexico, which in 2006 was among the first countries in the world to introduce rotavirus vaccine, diarrhoeal disease death rates dropped during the 2009 rotavirus season by more than 65 percent among children age two and under. In Nicaragua, which in 2006 became the first developing country to introduce a rotavirus vaccine, severe rotavirus infections were reduced by 40 percent and emergency room visits by a half. In the United States, rotavirus vaccination since 2006 has led to drops in rotavirus-related hospitalisations by as much as 86 percent. The vaccines may also have prevented illness in non-vaccinated children by limiting the number of circulating infections. In developing countries in Africa and Asia, where the majority of rotavirus deaths occur, a large number of safety and efficacy trials as well as recent post-introduction impact and effectiveness studies of Rotarix and RotaTeq have found that vaccines dramatically reduced severe disease among infants. In September 2013, the vaccine was offered to all children in the UK, aged between two and three months, and it is expected to halve the cases of severe infection and reduce the number of children admitted to hospital because of the infection by 70 percent. In Europe, hospitalisation rates following infection by rotavirus have decreased by 65% to 84% following the introduction of the vaccine. Globally, vaccination has reduced hospital admissions and emergency department visits by a median of 67%.

Rotavirus vaccines are licensed in over 100 countries, and more than 80 countries have introduced routine rotavirus vaccination, almost half with the support of Gavi, the Vaccine Alliance. To make rotavirus vaccines available, accessible, and affordable in all countries—particularly low- and middle-income countries in Africa and Asia where the majority of rotavirus deaths occur, PATH (formerly Program for Appropriate Technology in Health), the WHO, the U.S. Centers for Disease Control and Prevention, and Gavi have partnered with research institutions and governments to generate and disseminate evidence, lower prices, and accelerate introduction.

Antigen detection, polymerase chain reaction assay, virus isolation, and serology can be used to identify adenovirus infections. Adenovirus typing is usually accomplished by hemagglutination-inhibition and/or neutralization with type-specific antisera. Since adenovirus can be excreted for prolonged periods, the presence of virus does not necessarily mean it is associated with disease.

With most infections, the key is to block the spread of the organism.

- Wash hands frequently

- Eat properly prepared and stored food.

- Bleach soiled laundry

- Vaccinations for "Vibrio cholerae" and rotavirus have been developed. Rotavirus vaccination is recommended for infants in the U.S. Vaccines for "V. cholerae" may be administered to individuals traveling to at-risk areas

Antibody (Ig) ELISAs are used to detect historical BVDV infection; these tests have been validated in serum, milk and bulk milk samples. Ig ELISAs do not diagnose active infection but detect the presence of antibodies produced by the animal in response to viral infection. Vaccination also induces an antibody response, which can result in false positive results, therefore it is important to know the vaccination status of the herd or individual when interpreting results. A standard test to assess whether virus has been circulating recently is to perform an Ig ELISA on blood from 5–10 young stock that have not been vaccinated, aged between 9 and 18 months. A positive result indicates exposure to BVDV, but also that any positive animals are very unlikely to be PI animals themselves. A positive result in a pregnant female indicates that she has previously been either vaccinated or infected with BVDV and could possibly be carrying a PI fetus, so antigen testing of the newborn is vital to rule this out. A negative antibody result, at the discretion of the responsible veterinarian, may require further confirmation that the animal is not in fact a PI.

At a herd level, a positive Ig result suggests that BVD virus has been circulating or the herd is vaccinated. Negative results suggest that a PI is unlikely however this naïve herd is in danger of severe consequences should an infected animal be introduced. Antibodies from wild infection or vaccination persist for several years therefore Ig ELISA testing is more valuable when used as a surveillance tool in seronegative herds.

Cultures of stool samples are examined to identify the organism causing dysentery. Usually, several samples must be obtained due to the number of amoebae, which changes daily. Blood tests can be used to measure abnormalities in the levels of essential minerals and salts.

A clinical diagnosis may be made by taking a history and doing a brief examination. Treatment is usually started without or before confirmation by laboratory analysis.

"Campylobacter" organisms can be detected by performing a Gram stain of a stool sample with high specificity and a sensitivity of ~60%, but are most often diagnosed by stool culture. Fecal leukocytes should be present and indicate the diarrhea to be inflammatory in nature. Methods currently being developed to detect the presence of campylobacter organisms include antigen testing via an EIA or PCR.

Antigen ELISA and rtPCR are currently the most frequently performed tests to detect virus or viral antigen. Individual testing of ear tissue tag samples or serum samples is performed. It is vital that repeat testing is performed on positive samples to distinguish between acute, transiently infected cattle and PIs. A second positive result, acquired at least three weeks after the primary result, indicates a PI animal. rtPCR can also be used on bulk tank milk (BTM) samples to detect any PI cows contributing to the tank. It is reported that the maximum number of contributing cows from which a PI can be detected is 300.

The best prevention against viral pneumonia is vaccination against influenza, adenovirus, chickenpox, herpes zoster, measles, and rubella.

Numerous studies have shown that improvements in drinking water and sanitation (WASH) lead to decreased risks of diarrhoea. Such improvements might include for example use of water filters, provision of high-quality piped water and sewer connections.

In institutions, communities, and households, interventions that promote hand washing with soap lead to significant reductions in the incidence of diarrhea. The same applies to preventing open defecation at a community-wide level and providing access to improved sanitation. This includes use of toilets and implementation of the entire sanitation chain connected to the toilets (collection, transport, disposal or reuse of human excreta).

Safe and effective adenovirus vaccines were developed for adenovirus serotypes 4 and 7, but were available only for preventing ARD among US military recruits, and production stopped in 1996. Strict attention to good infection-control practices is effective for stopping transmission in hospitals of adenovirus-associated disease, such as epidemic keratoconjunctivitis. Maintaining adequate levels of chlorination is necessary for preventing swimming pool-associated outbreaks of adenovirus conjunctivitis.

The doctor will take a medical history to make sure that nothing else is causing the symptoms. Also, the doctor might perform a rectal or abdominal examination to exclude the possibilities of inflammatory bowel disease (e.g., Crohn’s disease) and pelvic abscesses (pockets of pus). A stool culture (a laboratory test to identify bacteria and other organisms from a sample of feces) can be used to determine the specific virus or germ that is causing gastroenteritis.

Diagnosis can be made in several ways, encompassing a range of multi-faceted techniques:

- Isolation and detection of the virus in cell culture.

- Detection of viral antigens directly within bodily respiratory tract secretions using immunofluorescence, enzyme immunoassays or fluroimmunoassays.

- Polymerase chain reaction (PCR).

- Analysis of specific IgG antibodies showing a subsequent rise in titre following infection (using paired serum specimens).

Because of the similarity in terms of the antigenic profile between the viruses, hemagglutination assay (HA) or hemadsorption inhibition (HAdI) processes are often used. Both complement fixation, neutralisation and enzyme linked immunosorbent assays – ELISA, can also be used to aid in the process of distinguishing between viral serotypes.

The following types of diarrhea may indicate further investigation is needed:

- In infants

- Moderate or severe diarrhea in young children

- Associated with blood

- Continues for more than two days

- Associated non-cramping abdominal pain, fever, weight loss, etc.

- In travelers

- In food handlers, because of the potential to infect others;

- In institutions such as hospitals, child care centers, or geriatric and convalescent homes.

A severity score is used to aid diagnosis in children.

One study suggests that on very long trips in the wilderness, taking multivitamins may reduce the incidence of diarrhea.

Viral disease is usually detected by clinical presentation, for instance severe muscle and joint pains preceding fever, or skin rash and swollen lymph glands.

Laboratory investigation is not directly effective in detecting viral infections, because they do not themselves increase the white blood cell count. Laboratory investigation may be useful in diagnosing associated bacterial infections, however.

Viral infections are commonly of limited duration, so treatment usually consists in reducing the symptoms; antipyretic and analgesic drugs are commonly prescribed.

Treatment is symptomatic and aims to prevent dehydration in young pigs, using products such as electrolyte and energy supplements. Good biosecurity protocols such as adequate quarantine, isolation of cases, and disinfection help prevent entry or spread of the disease in the herd. In Canada, the Canadian Swine Health Board developed detailed protocols on how to adequately disinfect transportation vehicles for live hogs and ensure the quality of the disinfecttion protocol.

Many cases of croup have been prevented by immunization for influenza and diphtheria. At one time, croup referred to a diphtherial disease, but with vaccination, diphtheria is now rare in the developed world.

The World Health Organization recommends the following:

- Food should be properly cooked and hot when served.

- Consume only pasteurized or boiled milk and milk products, never raw milk products.

- Make sure that ice is from safe water.

- If you are not sure of the safety of drinking water, boil it, or disinfect it with chemical disinfectant.

- Wash hands thoroughly and frequently with soap, especially after using the toilet and after contact with pets and farm animals.

- Wash fruits and vegetables thoroughly, especially if they are to be eaten raw. Peel fruits and vegetables whenever possible.

- Food handlers, professionals and at home, should observe hygienic rules during food preparation.

- Professional food handlers should immediately report to their employer any fever, diarrhea, vomiting or visible infected skin lesions.

Different types of water sources may have different levels of contamination:

- More contamination may be in water that

1. likely could have passed through an area subject to heavy human or animal use

2. is cloudy, has surface foam, or has some other suspicious appearance.

- Less contamination may be in water from

1. springs (provided the true source is not surface water a short distance above)

2. large streams (those entering from the side may have less contamination than those paralleling the trail)

3. fast-flowing streams

4. higher elevations

5. lakes with undisturbed sediments (10 days undisturbed water storage can result in 75-99% removal of coliform bacteria by settling to the bottom)

6. freshly melted snow

7. deep wells (provided they aren't subject to contamination from surface runoff)

8. regions where there was a heavy snow year when streams run full and long compared to dry years.

Rain storms can either improve or worsen water quality. They can wash contaminants into water and stir up contaminated sediments with increasing flow, but can also dilute contaminants by adding large amounts of water.

Unfortunately, there have not been any epidemiological studies to validate the above, except possibly for the case of spring water.