Outbreak of Norovirus Illness Among Wildfire Evacuation Shelter Populations - Butte and Glenn Counties, California, November 2018.

The Camp Fire, California's deadliest wildfire, began November 8, 2018, and was extinguished November 25 (1). Approximately 1,100 evacuees from the fire sought emergency shelter. On November 10, acute gastroenteritis (AGE) was reported in two evacuation shelters; norovirus illness was suspected, because it is commonly detected in shelter-associated AGE outbreaks. Norovirus is highly contagious and resistant to several disinfectants. Butte County Public Health Department (BCPHD), assisted by the California Department of Public Health (CDPH), initiated active surveillance to identify cases, confirm the etiology, and assess shelter infection prevention and control (IPC) practices to guide recommendations. During November 8-30, a total of 292 patients with AGE were identified among nine evacuation shelters; norovirus was detected in 16 of 17 unique patient stool specimens. Shelter IPC assessments revealed gaps in illness surveillance, isolation practices, cleaning, disinfection, and handwashing. CDPH and BCPHD collaborated with partner agencies to implement AGE screening, institute isolation protocols and 24-hour cleaning services, and promote proper hand hygiene. During disasters with limited resources, damaged infrastructure, and involvement of multiple organizations, establishing shelter disease surveillance and IPC is difficult. However, prioritizing effective surveillance and IPC at shelter activation is necessary to prevent, identify, and contain outbreaks.

Outbreak of Epidemic Keratoconjunctivitis Caused by Human Adenovirus Type D53 in an Eye Care Clinic - Los Angeles County, 2017.

On June 22, 2017, the Los Angeles County Department of Public Health (LAC DPH) was notified of seven patients who were seen at an eye care clinic on June 8, 2017, and later developed symptoms of epidemic keratoconjunctivitis (EKC). EKC is a contagious, severe form of viral conjunctivitis that can cause pain and blurred vision for up to 4 weeks (1). LAC DPH conducted an investigation, which identified 17 patients with EKC, including 15 who had visited the optometry clinic and two who were household contacts of clinic patients. Observations in the clinic found deficiencies in disinfection of tonometers (an instrument connected to a slit lamp and used to test for glaucoma by measuring intraocular pressure) and multiuse eye drop administration. Staff member education and revision of disinfection practices interrupted further transmission. Patient specimens tested positive for human adenovirus (HAdV) type D53 (HAdV-53). As the first documented EKC outbreak associated with HAdV-D53 in the United States, this outbreak highlights the need for rigorous implementation of recommended infection prevention practices in eye care settings.

Three Rotavirus Outbreaks in the Postvaccine Era - California, 2017.

Before the introduction of rotavirus vaccine in 2006, rotavirus was the most common cause of severe diarrhea among U.S. children (1). Currently, two rotavirus vaccines are licensed for use in the United States, both of which have demonstrated good field effectiveness (78%-89%) against moderate to severe rotavirus illness (2), and the use of these vaccines has substantially reduced the prevalence of rotavirus in the United States (3). However, the most recent national vaccine coverage estimates indicate lower full rotavirus vaccine-series completion (73%) compared with receipt of at least 3 doses of vaccines containing diphtheria, tetanus, and pertussis antigens (95%), given on a similar schedule to rotavirus vaccines (4). In the postvaccine era in the United States, rotavirus activity persists in a biennial pattern (3). This report describes three rotavirus outbreaks that occurred in California in 2017. One death was reported; however, the majority of cases were associated with mild to moderate illness, and illness occurred across the age spectrum as well as among vaccinated children. Rotavirus vaccines are designed to mimic the protective effects of natural infection and are most effective against severe rotavirus illness (2). Even in populations with high vaccination coverage, some rotavirus infections and mild to moderate illnesses will occur. Rotavirus vaccination should continue to be emphasized as the best means of reducing disease prevalence in the United States.

Single-step RT-PCR assay for dual genotyping of GI and GII norovirus strains.

BACKGROUND: Noroviruses are the major cause of acute gastroenteritis (AGE) in people of all ages globally. Standardized genotyping is key for outbreak investigations and surveillance networks. OBJECTIVE: Here we describe the validation of a one-step conventional RT-PCR assay for sequence-based dual typing of GI and GII noroviruses. This polymerase (P) and capsid (C) dual typing assay uses a combination of previously published oligonucleotide primers amplifying a genomic region spanning the 3'-end of ORF1 and 5'end of ORF2 resulting in a 579 bp product for GI and 570 bp product for GII viruses. RESULTS: The limit of detection of the assay ranged from 5 to 50 copies of viral RNA per reaction for GI and GII. To validate the assay, we tested 2,663 noroviruspositive stool samples from outbreaks and sporadic cases of AGE in Bangladesh, Guatemala, Peru, and USA collected between 2010-2019, of which 2,392 (90 %) were genotyped successfully. Most of the known genotypes infecting humans (GI (n = 9) and GII (n = 23)) and P types (GI (n = 15), GII, (n = 20)) could be detected. The remaining 270 samples had low viral load (Ct > 30) by real-time RT-PCR. A panel of 166 samples positive for other enteric viruses (rotavirus, astrovirus, sapovirus, adenovirus type 40/41) tested negative. CONCLUSION: The use of broadly reactive genotyping assays greatly strengthens exchange of standardized genotype data globally to monitor trends in genotype diversity which is important for both the development of vaccines and to measure their impact.

Nearly Complete Genome Sequence of an Echovirus 30 Strain from a Cluster of Aseptic Meningitis Cases in California, September 2017.

We report the nearly complete genome sequence of a human enterovirus, a strain of echovirus 30, obtained from a cerebrospinal fluid specimen from a teenaged patient with aseptic meningitis in September 2017.