Lab Matters Fall 2018 | Page 30

FOOD SAFETY APHL and CaliciNet: Improving Norovirus Surveillance and Outbreak Detection by Kirsten Larson, MPH, manager, Food Safety CaliciNet is comprised of federal, state and local public health laboratories that detect and subtype norovirus strains associated with gastroenteritis outbreaks in the US. 1 Created in 2009, CaliciNet provides a way for the US Centers for Disease Control and Prevention (CDC) to compare norovirus strains from outbreaks and potentially link them to a common source, monitor circulating strains and detect emerging ones. 1 APHL carries out a number of activities to help increase awareness and participation and make improvements to this important network including assisting with training workshops for local and state public health laboratorians, coordinating CaliciNet user group meetings, and facilitating networking efforts among member laboratories participating in CaliciNet Outbreak Support Centers (OSC) and Unexplained Viral Diarrheal (UVD) Sites. 2 In fall 2017, APHL worked closely with members from the California Department of Public Health (CDPH) Viral and Rickettsial Disease Laboratory (VRDL), epidemiologists of CDPH’s Infectious Diseases Branch and CDC to organize the 2017 California Norovirus Laboratory Network Surveillance Meeting. Held at the CDPH laboratory campus in Richmond, CA, the meeting brought together laboratory, epidemiology and environmental health personnel from APHL, CDC, CDPH and 34 local health jurisdictions to explore ways to improve norovirus testing, surveillance and outbreak response in California. As one of five CaliciNet OSCs, CDPH is responsible for sequencing strains from norovirus outbreaks from other states and local CaliciNet provides a way for CDC to compare norovirus strains from outbreaks and potentially link them to a common source Rotavirus health laboratories that are not CaliciNet certified and uploading those sequences to the CaliciNet database. CDPH staff reported several successes resulting from the meeting. First, multiple local laboratories expressed interest in joining the California Norovirus Laboratory Network (NLN). The NLN is comprised of the CDPH/VRDL and 24 local public health laboratories capable of performing real time RT-PCR testing for norovirus. Second, local epidemiologists and laboratorians have made a concerted effort since the meeting to collect stool specimens during outbreaks. Notably, five local health departments successfully obtained specimens for a multinational norovirus outbreak linked to raw oysters from British Columbia that sickened ~100 individuals in California alone. Laboratory testing confirmed norovirus infection in several of those patients and sequencing linked them to a common source. Broader participation across multiple California counties provides a more comprehensive picture of predominating norovirus strains in the US and has provided invaluable information during outbreaks, leading to multistate product recalls. In addition to serving as an OSC, CDPH is also one of three UVD sites along with the Minnesota State Public Health Laboratory Division and Oregon State Public Health Laboratory. With funding provided by CDC, the UVD sites are contracted through APHL to test stool specimens from norovirus negative outbreaks for other viral enteric pathogens including rotavirus, sapovirus, astrovirus and adenovirus. The positive sequences and/ or PCR data from norovirus-negative outbreaks from other states are sent to CDC on a monthly basis. The UVD sites also send sapovirus, astrovirus and rotavirus negative samples to CDC for further analysis and pathogen discovery. From September 2013–June 2018, the UVD sites and CDC tested 244 3 Unpublished outbreak data from CDC and Unexplained Viral Diarrhea study sites. 1 2 28 LAB MATTERS Fall 2018 PublicHealthLabs @APHL