Rotavirus: Cause, Epidemiology and Symptoms

Introduction

Rotavirus is the leading cause of severe gastroenteritis in children less than 5 years of age. In 1973, rotavirus was discovered from duodenal biopsies and fecal samples taken from humans with acute diarrhea. Despite the availability of a vaccine against rotavirus, it continues to result in more than 200,000 deaths worldwide per year. In developed countries with routine vaccination programs, rotavirus infection is less prevalent than in non-developed countries where it continues to be a major cause of life-threatening diarrhea in infants and children under 5 years of age.

Rotavirus symptoms include profuse diarrhea, vomiting, fever, malaise, and rarely neurologic features such as convulsions, encephalitis, or encephalopathy. The most common symptoms are diarrhea and vomiting, leading to significant dehydration and reduced oral intake, which can necessitate hospitalization and lead to death if not treated.


BioTalk – Introduction to Rotavirus

Cause

Rotavirus is a double-stranded RNA virus, named for its classic “wheel-shaped” appearance on electron microscopy. Transmission of rotavirus primarily occurs through the fecal-oral route. Additionally, the viral spread can occur through contaminated hands, fomites, and rarely, food and water. Prior to the routine use of the rotavirus vaccines, the rates of rotavirus illness among children in low-income countries was similar to that of high-income countries. Since the advent of rotavirus vaccines, norovirus has exceeded rotavirus as the leading cause of acute viral gastroenteritis in high-income countries. In low-income countries and globally, rotavirus infections are the number one cause of acute viral gastroenteritis in children.

Epidemiology

Rotaviruses are found throughout the world, and most children are infected by 5 years of age. The frequency of infection is similar throughout the world; however, fatal infection is more likely in low-income regions throughout the globe. This is likely secondary to the lack of adequate healthcare facilities, increased rates of malnutrition, and lack of access to clean, sanitary hydration therapies. Rotavirus is traditionally thought of as a winter disease, especially in more temperate areas of the globe. In tropical climates, the seasonal trend is less evident, and infections tend to occur year-round. Some research has shown that the frequency of rotavirus infection in temperate climates may also be related to precipitation levels. One study out of Washington D.C. revealed that there was a 45% increase in rotavirus hospitalizations following months with low precipitation compared to months with higher levels of precipitation. This indicates that rotavirus transmission is more common in conditions of low humidity, as seen in winter and dry months throughout the year.

Ten different species of rotavirus are currently classified (A-J). Species A rotaviruses are the most common cause of childhood infections, with species B and C also causing a smaller but significant percentage of infections across the world. Geographical variances in the strains of species A rotaviruses have been seen circulating globally.

Rotavirus disease epidemiology has drastically changed since the development of vaccines against the virus. Prior to vaccine development, rotavirus infection was most common in children under the age of 5. Following widespread vaccination programs, rotavirus appears to be more prevalent in older, unvaccinated children. In low-income countries where rotavirus vaccines are not widespread, the prevalence of rotavirus infections appears to be stable. Malnutrition in these regions tends to increase the severity of disease.

Signs and Symptoms

Rotavirus has an incubation period varying from 1 to 3 days, after which symptoms appear abruptly with varying presentations. Symptoms congruent with infection are almost identical to other gastrointestinal infections; however, rotavirus infections tend to be more severe. Fever, diarrhea, and vomiting are the most common presenting symptoms. There is variability seen amongst infected patients ranging from short term, mild diarrhea to severe diarrhea with fever and vomiting. Symptoms are most severe in patients whose first infection occurs after 3 months of age. Infants most commonly present with mild symptoms and have a lower likelihood of severe infection. Some infants, however, have been found to present with necrotizing enterocolitis.

In rotavirus infection, vomiting often occurs initially, followed by watery diarrhea. Fever is found in approximately 33% of infected patients. Illness duration is anywhere from 5 to 7 days from onset to full resolution of symptoms. Physical exam findings, typically, do not clearly differentiate rotavirus from other pathogens known to infect the gastrointestinal tract commonly. Exam findings that may be present in individuals with rotavirus infection include fever, abdominal cramping, fatigue, and signs of dehydration such as dry mucous membranes, decreased skin turgor, tachycardia, diminished urine output, and prolonged capillary refill.

Source
LeClair CE, McConnell KA. Rotavirus. [Updated 2023 Jan 2]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK558951/

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