Boys are twice as likely as girls to be admitted to hospital. Rotavirus infections occur primarily during cool, dry seasons. The number attributable to food contamination is unknown.Outbreaks of rotavirus A diarrhoea are common among hospitalised infants, young children attending day care centres, and elderly people in nursing homes. An outbreak caused by contaminated municipal water occurred in Colorado in 1981. During 2005, the largest recorded epidemic of diarrhoea occurred in Nicaragua. This unusually large and severe outbreak was associated with mutations in the rotavirus A genome, possibly helping the virus escape the prevalent immunity in the population. A similar large outbreak occurred in Brazil in 1977.Rotavirus B, also called adult diarrhoea rotavirus or ADRV, has caused major epidemics of severe diarrhoea affecting thousands of people of all ages in China. These epidemics occurred as a result of sewage contamination of drinking water. Rotavirus B infections also occurred in India in 1998; the causative strain was named CAL. Unlike ADRV, the CAL strain is endemic. To date, epidemics caused by rotavirus B have been confined to mainland China, and surveys indicate a lack of immunity to this species in the United States. History
In 1943, Jacob Light and Horace Hodes proved that a filterable agent in the faeces of children with infectious diarrhoea also caused scours (livestock diarrhoea) in cattle. Three decades later, preserved samples of the agent were shown to be rotavirus. In the intervening years, a virus in mice was shown to be related to the virus causing scours.
Ellis–Van Creveld syndrome (also called  mesoectodermal dysplasia but see Nomenclature section below) is a rare genetic disorder of the skeletal dysplasia type. Signs and symptoms
It involves numerous anomalies including:

Post-axial polydactyly
Congenital heart defects (most commonly an atrial septal defect producing a common atrium, occurring in 60% of affected individuals)
Teeth present at birth (natal teeth)
Fingernail dysplasia
Short-limbed dwarfism, mesomelic pattern
Short ribs
Cleft palate
Malformation of the wrist bones (fusion of the hamate and capitate bones). Genetics
Ellis–Van Creveld syndrome often is the result of founder effects in isolated human populations, such as the Amish and some small island inhabitants. Although relatively rare, this disorder does occur with higher incidence within founder-effect populations due to lack of genetic variability. Observation of the inheritance pattern has illustrated that the disease is autosomal recessive, meaning that both parents have to carry the gene in order for an individual to be affected by the disorder.Ellis–Van Creveld syndrome is caused by a mutation in the EVC gene, as well as by a mutation in a nonhomologous gene, EVC2, located close to the EVC gene in a head-to-head configuration. The gene was identified by positional cloning. The EVC gene maps to the chromosome 4 short arm (4p16). The function of a healthy EVC gene is not well understood at this time. Relation to other rare disorders:  genetic ciliopathy
Until recently, the medical literature did not indicate a connection among many genetic disorders, both genetic syndromes and genetic diseases, that are now being found to be related.