Community Cohort Incidence Study
Objective: To establish the incidence and aetiology of infectious intestinal disease in the community and presenting to general practitioners, and compare with incidence and aetiology of cases reaching national laboratory based surveillance.
Protocol Steps
Study Design and Setting Establishment
Population based community cohort incidence study conducted across 70 general practices throughout England with 459,975 patients served by the practices.
Note: Multi-component study including general practice based incidence studies and case linkage to national laboratory surveillance
View evidence from paper
“Population based community cohort incidence study, general practice based incidence studies, and case linkage to national laboratory surveillance. Setting 70 general practices throughout England.”
Community Cohort Selection
Random selection of 9,776 patients from the community for surveillance of infectious intestinal disease.
Note: These patients were monitored for incidence of infectious intestinal disease in the community setting
View evidence from paper
“Community surveillance of 9776 randomly selected patients.”
Case Identification and Incidence Measurement
Identification of cases of infectious intestinal disease in the community cohort and measurement of incidence rates per 100 person years.
Note: 781 cases were identified in the community cohort
View evidence from paper
“781 cases were identified in the community cohort, giving an incidence of 19.4/100 person years (95% confidence interval 18.1 to 20.8).”
General Practice Presentation Monitoring
Monitoring of cases presenting to general practice from the 70 participating practices.
Note: 8,770 cases presented to general practice with incidence of 3.3/100 person years
View evidence from paper
“8770 cases presented to general practice (3.3/100 person years (2.94 to 3.75)).”
National Surveillance Linkage
Case linkage to national laboratory based surveillance to compare community cases with reported cases.
Note: One case was reported to national surveillance for every 1.4 laboratory identifications, 6.2 stools sent for laboratory investigation, 23 cases presenting to general practice, and 136 community cases
View evidence from paper
“One case was reported to national surveillance for every 1.4 laboratory identifications, 6.2 stools sent for laboratory investigation, 23 cases presenting to general practice, and 136 community cases.”
Microorganism Identification and Classification
Identification of causative organisms in cases and comparison of reporting ratios between bacterial and viral pathogens.
Note: Ratios varied by pathogen type: salmonella 3.2:1, campylobacter 7.6:1, rotavirus 35:1, small round structured viruses 1562:1
View evidence from paper
“The ratio of cases in the community to cases reaching national surveillance was lower for bacterial pathogens (salmonella 3.2:1, campylobacter 7.6:1) than for viruses (rotavirus 35:1, small round structured viruses 1562:1).”