RotavirusA09.0

Rotaviruses (rota, lat. = Rad) are the main cause of nosocomial intestinal infections in newborns and infants (Gervasi G et al. 2016). In adulthood rotavirus infections are significantly less frequent (12 % of the diseases in patients over 60 years of age).

Rotaviruses belong to the family Reoviridae. Within this family, rotavirus is the only important humapathogenic virus. Rotaviruses are non-enveloped (naked) virus particles (diameter 70-80nm) with a complex structure. They are three-layered (outer and inner isocedric capsid and core shell). Rotaviruses absorb at cellular structures (receptors) that carry neuraminic acid residues. A distinction is made between 7 serogroups (A-G). Rotaviruses of the group A have the greatest epidemiological importance worldwide. The antigenicity of the virus is determined by two proteins (VP4 and VP7) of the virus envelope. These envelope proteins also define the classification of the viruses according to the different serotypes (genotypes). A distinction is made between 16 VP7 types ("G-") and 27 VP4 types ("P-"). The largest proportion of rotavirus diseases in Germany is caused by rotaviruses of the types G1P and G4P, followed by G2P and G9P. Rotaviruses are extremely resistant to environmental influences.

Rotaviruses are spread worldwide (Gervasi G et al. 2016). The virus is transmitted via the fecal-oral route. However, aerosol transmission routes are also assumed.

The disease is seasonally more frequent and is highest in the months February to April. The viruses have a very high level of contagiousness. Diseased persons excrete very large amounts of the virus with the stool (109-1012 particles/g stool). In 2008, rotavirus infections were the second most common notifiable disease with 77,490 cases. In 2009, 62,207 rotavirus infections were reported to the RKI. 61% of these diseases (37,822) affected children up to the age of 5 years. 17% of the diseases (10,858) occurred in persons over 60 years of age.

In developing countries rotavirus diseases are of particular importance. They contribute significantly to child mortality. It is estimated that in Africa, Asia and Latin America more than 100 million children are affected annually and about 350,000 to 600,000-900,000 children aged < 5 years die from rotavirus infections.

The virus multiplies in the differentiated epithelial cells at the tips of the villi of the small intestine, infecting only the enterocytes of the tip of the villus and not those of the crypts. The infection leads to cytolysis of the affected cells. These show a strong vacuolisation and detach from the tissue. As a consequence, a drastic shortening of the villi of the duodenum is observed, combined with considerable resorption disturbances. After the onset of the immune response, the virus is eliminated and after 6-7 days the villi are completely restored by cryptic enterocytes.

In the western industrialized countries, infants and children aged 6 months to 2 years are most frequently affected (the reason for this is their high susceptibility due to the naivety of their immune system). During the first years of life, repeated rotavirus infections build up rotavirus-specific immunity. However, this immunity is not permanent. By the age of 3 years 90% of all children have undergone rotavirus infection, by the age of 5 years almost all children have become infected with rotaviruses. In adulthood, infections are less frequent but not excluded (12% of cases in >60 year old patients). They are usually milder - especially as travel diarrhoea. In persons > 60 years of age the incidence of the disease increases again. Although almost all adults have antibodies against rotaviruses, recurrent infections are possible in all age groups (Crawford SE et al. 2017).

After an incubation period of 1-3 days, watery to slimy, colorless to yellow-brown diarrhea (no blood!) occurs, which may be associated with vomiting and abdominal pain. The temperature is only slightly elevated (38 °C). Rotavirus-induced enteritis cannot be clinically distinguished from other infection-related gastroenteritis.

However, in infants and toddlers it is on average more severe than diarrhoea caused by other pathogens. The gastrointestinal symptoms usually persist for 2 to 6 days. In < 50% of cases, non-specific respiratory symptoms are observed. Complicated are the diseases in the course of which dehydration occurs. If not treated adequately in time, dehydration can lead to death (Crawford SE et al. 2017).

The laboratory diagnostic method of choice is the detection of a group-specific antigen of the inner capsid from the stool using the "enzyme immune test" (EIA). The direct detection of the virus by electron microscopy is easily possible, but is rarely carried out due to the high effort involved (an advantage of this method is the broad viral differential diagnosis).

Virus cultivation is difficult and therefore not a routine method. Infection chains can best be reconstructed by molecular biological examination methods Reverse transcription polymerase chain reaction (RT-PCR) and sequencing of the amplificate. Meaningful serological standard tests do not exist.

Usually, oral substitution of fluid and electrolytes is sufficient. Hospital treatment is necessary if intravenous fluid intake is required. Antiviral therapy does not exist. Antibiotics and agents that inhibit intestinal motility are not indicated.

Measures for patients and contacts: To prevent transmission by faecal-oral routes, hygiene measures should be extended, particularly in the symptomatic phase:

• separation of the sick persons, if necessary cohort isolation/care
• Wearing gloves and protective clothing to prevent infection
• consistent hand hygiene, hand disinfection
• Disinfection of surfaces close to the patient and frequent hand contact surfaces (e.g. door handles) as well as toilets and wash basins
• For disinfection, preparations with proven efficacy with the efficacy range "limited virucidal PLUS" or "virucidal" are suitable (testing and declaration of the efficacy of disinfectants against viruses for use in the human-medical sector (Federal Health Gazette 3/2017).
• According to § 34 para. 1 IfSG , children < 6 years of age suffering from or suspected of suffering from infectious gastroenteritis are not allowed to visit community facilities. Children suffering from or suspected of suffering from infectious gastroenteritis who have not yet reached the age of 6 years may be readmitted 48 hours after the clinical symptoms have subsided. For further information see the recommendations of the RKI for the readmission to community facilities according to § 34 IfSG.
• The restriction of the activity or the visit to the joint facility applies until there is no longer any reason to fear a further spread of the disease according to medical opinion. The medical judgement may be the judgement of the attending physician or a physician from the competent health authority. The medical opinion may be given orally. § 34 IfSG does not require a written certificate of the medical judgement, but it may be useful for the protection of all concerned.
• Similarly, persons who are ill may not work in food-related occupations (defined in § 42 IfSG). A resumption of work should take place at the earliest 2 days after the clinical symptoms have subsided. During the following 4 to 6 weeks, special care must be taken to ensure hand hygiene at the workplace. If the symptoms reoccur, a new leave of absence is necessary.

Measures to be taken in case of outbreaks: In case of rotavirus diseases (hospitals, community facilities or old people's homes), the rapid clinical differentiation of occurring rotavirus infections from other gastroenteritis, e.g. those caused by food toxins, forms the basis of effective outbreak prevention. If the typical symptoms and epidemiological features indicate rotavirus infection, preventive measures should be consistently implemented without waiting for confirmation by virological tests, due to the epidemic potency of rotavirus. It is recommended that persons suffering from rotavirus infection should not carry out care activities in health and community facilities during the symptomatic phase.

The main recommended measures are:

• Isolation of affected patients in a room with private WC; cohort isolation if necessary;
• Instruction of patients and staff on correct hand hygiene, use of a hand disinfectant with a "limited virucidal PLUS" or "virucidal" effect and care of patients with disposable gloves, protective gowns and, if necessary, suitable respiratory protection to prevent infection associated with vomiting;
• Carrying out careful hand hygiene, application of a hand disinfectant with the "limited virucidal PLUS" or "virucidal" effect after taking off the disposable gloves and before leaving the isolation room;
• Daily (in sanitary areas more often if necessary) wipe disinfection of all contact surfaces near the patient including door handles with a surface disinfectant with the "limited virucidal PLUS" or "virucidal" effect;
• clean contaminated surfaces (e.g. with a chair) immediately with targeted disinfection;
• use and disinfect care utensils in a personalised manner;
• Transport bed and body linen as infectious laundry in a closed laundry bag and clean and disinfect with a chemo-thermal washing process with virucidal effectiveness;
• machine wash dishes (as a rule) as usual;
• inform contact persons (e.g. visitors, family) of the possible human-to-human transmission through contact and instruct them in correct hand disinfection;
• Minimise patient and resident movement between areas/ wards in order to prevent the spread within the facility as far as possible (point out the risk of infection if a sick person has to be transferred to another ward);
• strict indication of acutely ill patients with regard to transfers within inpatient areas, nursing homes or community facilities. The receiving institution must be informed in advance.
• Wards or areas that were closed to new admissions of patients due to an outbreak of rotavirus should only be reopened after final disinfection, taking into account the incubation period after the last case of illness.
• For the reprocessing of medical devices, we refer to the corresponding recommendations of the Commission for Hospital Hygiene and Infection Prevention ("Hygiene requirements for the reprocessing of medical devices" and "Hygiene requirements for the reprocessing of flexible endoscopes and additional endoscopic instruments" see www.rki.de/Infektionsschutz > Hospital Hygiene).
• In the case of larger outbreaks, it is not necessary to carry out a diagnosis for all affected persons. In these cases, it is usually sufficient to diagnose a maximum of 5 of the affected persons and then to diagnose rotavirus infection in the other patients from the same environment with similar symptoms. It is important to point out that hygienic measures are of decisive importance even after the acute symptoms have ceased. The detection of the pathogen in the stool can remain positive for a long time after the symptoms have subsided. Careful hand hygiene must therefore be ensured in the following period.
• In order to avoid outbreaks, sick staff should be released from work even if the gastrointestinal symptoms are minor and should not resume work with careful attention to hand hygiene until at least 2 days after the end of the clinical symptoms. Monitoring of virus excretion is not indicated.

There is an obligation to report in accordance with the IfSG. According to § 7 para. 1 IfSG the direct or indirect evidence of rotavirus, if it indicates an acute infection, is reported by name to the responsible public health office.

Furthermore, according to § 6 para. 1 No. 2 IfSG, the suspicion of and the illness of acute infectious gastroenteritis must be reported,

if the person concerned handles food or is employed in catering establishments (e.g. kitchens, restaurants) (see measures for patients and contact persons), or

if two or more similar diseases occur for which an epidemic link is probable or suspected

The reports must be submitted to the public health department within 24 hours of their discovery.

1In § 8 IfSG the persons obliged to report are named (https://www.gesetze-im-internet.de/ifsg/__8.html). Section 9 IfSG stipulates the information that may be included in the notification to the public health department (https://www.gesetze-im-internet.de/ifsg/__9.html).

Obligation to notify according to IfSG

In accordance with § 34 Para. 6 IfSG, heads of community facilities must inform the responsible health authority immediately if children who are cared for in their facility and are under 6 years of age fall ill with infectious gastroenteritis or are suspected of having it.

Notification: In accordance with § 11 para. 1 IfSG, the public health office only notifies the competent state authority of cases of illness or death and pathogen evidence that correspond to the case definition in § 11 para. 2 IfSG.

The case definitions prepared by the RKI are published on the RKI website at www.rki.de/falldefinitionen.

1. Crawford SE et al (2017) Rotavirus infection. Nat Rev Dis Primers 3:17083.
2. Gervasi G et al (2016) Nosocomial rotavirus infection: An up to date evaluation of European studies. Hum Vaccine Immunother. 12:2413-2418.
3. Lee KS et al (2018) The economic burden of rotavirus infection in South Korea from 2009 to 2012, PLoS One 13:e0194120.
4. RKI Guide(2018, taken on 15.3.20209 https://www.rki.de/DE/Content/Infekt/EpidBull/Merkblaetter/Ratgeber_Rotaviren.html;jsessionid=F126091F5EDACBC89C78312CF3BAD85E.internet061#doc2374564bodyText2
5. Schnitzler P et al (2019) Rotavirus. In: Hof H, Schlüter D, Dörries R, ed. Duale Reihe Medizinische Mikrobiologie. 7th, completely revised and extended edition. Stuttgart: Thieme p. 246-247
6. Velázquez FR et al (1996) Rotavirus infection in infants as protection against subsequent infections. N Engl J Med 335:1022-1028.