Generality
Rotavirus is the viral agent responsible for most juvenile cases of gastroenteritis.
Generally, the symptoms of rotavirus gastroenteritis consist of: nausea, vomiting, fever and watery diarrhea.
The most feared complication is dehydration, following repeated episodes of vomiting and dysentery.
In most cases, physical examination and medical history are sufficient to detect a rotavirus infection.
There are no specific treatments, only symptomatic treatments.
The patient's rehydration is essential to avoid serious complications.
What is rotavirus?
Rotavirus is the biological agent that represents the main cause of gastroenteritis in infants and children.
The genome of several double-stranded RNA molecules, the rotavirus belongs to the viral family known as Reoviridae .
What is gastroenteritis
With the term gastroenteritis, doctors indicate an inflammation of the stomach and intestines.
Generally, gastroenteritis has an infectious origin; however, in some cases, it may arise due to the ingestion of toxic metals, drugs, plants or fungi.
SPECIES OF ROTAVIRUS
To date, the virologists have identified 8 species of rotavirus, identified with the first eight capital letters of the alphabet, then A, B, C, D, E, F, G and H.
Of the 8 Rotavirus species so far identified, the Rotavirus A species is the most widespread. In fact, this is responsible for more than 90% of so-called rotavirus infections.
SOME FEATURES OF THE ROTAVIRUS
The rotavirus genome consists of 11 double-stranded RNA molecules, identified with the Arabic numerals 1 to 11.
All together, these 11 double-stranded RNA molecules possess exactly 18, 555 nucleotides .
Except for the RNA molecule number 9 - which encodes two genes - all other RNA molecules code for one gene only.
The rotavirus is a particle whose diameter measures 76.5 nanometers .
HISTORY OF THE ROTAVIRUS
The merit of the rotavirus discovery belongs to the Australian virologist Ruth Bishop and her team of colleagues. It was the year 1973.
The introduction in the medical jargon of the term "rotavirus" dates back to 1974: this word was coined by another virologist, a certain Thomas Henry Flewett, who on the electron microscope noticed the particular wheel shape of the rotavirus ("rota" is the Latin term which, in Italian, means "wheel").
Beginning in 1980, researchers studying rotavirus began to identify the various viral species existing in nature and capable of infecting humans.
Epidemiology
According to some statistical studies, the rotavirus would cause millions and millions of infections every year, resulting in about 2 million hospitalizations and causing the death of almost 453, 000 children under 5 years of age.
However, it should be pointed out that since rotavirus vaccines have existed, the annual number of rotavirus infections is clearly decreasing (obviously in countries where vaccination is possible).
Rotavirus is so common that, in the opinion of doctors and virologists, almost all children contract this viral agent at least once within the first 5 years of life.
The probability of developing a rotavirus infection is greater during the cold and / or dry seasons.
In the adult population, rotavirus infections are very rare.
Rotavirus in the USA before the vaccine
Before the creation of ad hoc vaccines, in the USA, every year, the cases of rotavirus infection were about 2.7 million.
Of these 2.7 million cases of infection, about 60, 000 required hospitalization and about 37 caused the death of the individual concerned.
Causes
Rotavirus transmission can take place in different ways:
- Via the so - called fecal-oral route ( fecal-oral transmission ). This mode of transmission means that the pathogen is able to find itself in the faeces.
In the specific case, the rotavirus has the aforementioned capacity.
- Through physical contact with contaminated hands, surfaces, food or objects.
- Via the respiratory tract . In this case, to transmit the viral agent are small volatile droplets of saliva, which expel infected people when they talk, sneeze, cough etc.
The fecal-oral transmission is, by far, the most widespread and the one that causes the greatest number of infections. Moreover, consider that the faeces of a subject infected by the rotavirus contain about 10 trillion viral particles per gram and that, to develop a rotavirus gastroenteritis, less than 100 viral particles per gram are sufficient.
SOME CURIOSITIES ABOUT THE TRANSMISSION OF THE ROTAVIRUS
The rotavirus is quite stable in the environment and is able to survive there, waiting to infect someone, for a period of time ranging from 9 to 19 days.
Furthermore, it is curious how, in the countries of the world where sanitary measures are inadequate, the incidence rate of rotavirus infections is comparable to the incidence rate of rotavirus infections calculated for the countries of the world where the sanitary measures are all 'vanguard.
RISK FACTORS
The subjects most at risk of rotavirus infection are children aged between 3 and 35 months .
Symptoms and Complications
The symptoms and signs of a rotavirus infection appear approximately two weeks after exposure to the pathogen. So the incubation period of the rotavirus is about 14-15 days .
The resulting gastroenteritis, which may be moderate or severe, initially causes a mild fever, nausea and vomiting ; at a later time (usually after 3-7 days), recurrent episodes of watery diarrhea (or dysentery) and severe abdominal pain appear.
ROTAVIRUS IN ADULTS
In adults who are in good health, rotavirus infections cause very mild, often almost imperceptible, manifestations.
In other words, they are partially or totally asymptomatic .
Why are adults less susceptible to rotavirus infections?
Adults are less prone to rotavirus infections for at least two reasons:
- They have probably already contracted the virus at a young age, so they have developed an antibody immunity that protects them from subsequent infections.
- They have a mature and more effective immune system than a child's.
AS ROTAVIRUS CAUSE GASTROENTERITE
From a pathophysiological point of view, rotavirus causes gastroenteritis because, when it enters the body, it attacks and destroys enterocytes .
Enterocytes are the epithelial cells that line the inner wall of the small intestine; in this case, it is the cellular elements that cover the intestinal villi .
WHEN TO REFER TO THE DOCTOR?
In the case of young or very young patients, it is advisable to contact the doctor in the presence of:
- Diarrhea for more than 24 consecutive hours
- Recurrent vomiting
- Feces of black color or containing blood and / or traces of pus
- Fever at 40 ° C or higher
- Lethargy, irritability and / or severe pain
- Dehydration
In the case of adult patients, it is advisable to consult the doctor in the presence of:
- Diarrhea episodes at least twice a day
- Inability to retain ingested liquids for more than 24 hours
- I vomit with blood
- Repeated bowel movements
- Fever at 39 ° C or higher
- Dehydration
COMPLICATIONS
The most important complication of rotavirus infections is dehydration following recurrent episodes of watery diarrhea.
If left untreated and in the right way, dehydration can bring the person concerned to death.
- Dizziness in getting up from a sitting position
- Decline of urination
- Dry mouth
- Plants without tears
- Unusual sleepiness
- Great sense of thirst
- Sense of weakness
- Dizziness
Diagnosis
The rotavirus causes an infection that doctors generally diagnose through a thorough physical examination and a careful medical history (clinical history).
If there are any doubts, the examination that definitively clarifies the origin of diarrhea and other symptoms of gastroenteritis is the analysis of a patient 's stool sample .
The analysis of the fecal sample includes a series of laboratory tests, aimed at finding the rotavirus.
Treatment
The treatments available for the treatment of rotavirus infections are non-specific and consist substantially of symptomatic therapies . A symptomatic type of therapy is a therapeutic intervention aimed at improving the symptoms.
Among the various symptomatic remedies, it is very important to maintain the hydration of the infected person. If the fluid intake is adequate to the patient's requests, the risk of complications is minimal and the chances of recovery are high.
REHYDRATION: WHAT IS IT?
The rehydration of a person with a rotavirus infection consists in the administration of water-based liquids, minerals and sugars .
Mineral salts are particularly important, as vomiting and diarrhea cause a great loss.
WHAT TO DO IN CASE OF SEVERE DEHYDRATION?
If rotavirus infection has caused severe dehydration, it is necessary to hospitalize the affected patient and give them fluids for intravenous rehydration.
DO WE NEED DRUGS AGAINST DIARREA?
Generally, the treatment of rotavirus infections does not involve the administration of drugs against diarrhea (antidiarrheal drugs).
This indication is also valid for those infectious states characterized by severe dysentery.
Prognosis
In general, if the patient recovers the fluids that he loses due to diarrhea and / or vomiting, a classic rotavirus infection resolves within 3-7 days, without repercussions of any kind.
Prevention
As mentioned, today there is the possibility of vaccinating against rotavirus .
To be more precise, there are two types of vaccines, both very effective and safe. These two types of vaccines specifically protect against rotavirus species A, fall into the category of live attenuated vaccines and are taken orally . To consult the relative technical data sheets, see the summary of the characteristics of the Rotarix and RotaTeq vaccines.
The marketing of rotavirus A vaccines is fairly recent. In fact, it dates back to 2006 (after obviously a long series of experiments).
Currently, more than 100 countries in the world are licensed to use the aforementioned vaccines, but only 28 of these have introduced the rotavirus vaccine among routine vaccinations.
