National epidemic of Lordsdale Norovirus in the UK.
BACKGROUND
In early 2002 reports of outbreaks of gastroenteritis reached unprecedented levels in the UK. Forty five Norovirus outbreaks were reported in January 2002.


OBJECTIVE
The objective of the study was to determine whether the outbreaks were Noroviral in origin and if so whether they represented a homogeneous or heterogeneous collection of Noroviruses by applying EIA and sequence analysis to representative faecal samples.


METHODS
Faecal specimens were collected during the week of highest incidence from 21 outbreaks in a variety of health care settings including hospitals and nursing homes. The outbreaks occurred in geographically distinct regions of the UK and samples were collected by reference laboratories in Glasgow, Manchester, Bristol and Southampton.


RESULTS
The samples were all positive for Noroviruses by negative stain electron microscopy (EM) and Lordsdale virus (LV) EIA, therefore reverse transcriptase polymerase chain reaction (RT-PCR) amplification and nucleotide sequencing of the Norovirus RNA polymerase gene was performed on amplicons from samples of each of the 21 outbreaks to investigate the nature and extent of diversity. All samples were very closely related to the reference Lordsdale virus genome sequence. LV was first discovered during an hospital outbreak of gastroenteritis in Southampton General Hospital in March 1993.


CONCLUSIONS
Noroviruses are a major cause of outbreaks of gastroenteritis in health care settings. LV is the predominant Norovirus in the UK and was detected in outbreaks that occurred during the national peak of gastroenteritis reports in January 2002.
Vipond
I B
IB
Bristol Public Health Laboratory, Myrtle Road, Bristol, BS2 8EL, UK.
Caul
E O
EO
Hirst
D
D
Carmen
B
B
Curry
A
A
Lopman
B A
BA
Pead
P
P
Pickett
M A
MA
Lambden
P R
PR
Clarke
I N
IN
D000595:Amino Acid Sequence; D017250:Caliciviridae Infections / Q000453:epidemiology*; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry / Q000235:genetics; D004196:Disease Outbreaks; D005243:Feces / Q000821:virology; D005759:Gastroenteritis / Q000453:epidemiology*; D006801:Humans; D007124:Immunoenzyme Techniques; D008969:Molecular Sequence Data; D029322:Norovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D017422:Sequence Analysis, DNA; D006113:United Kingdom / Q000453:epidemiology
D012321:DNA-Directed RNA Polymerases