An outbreak of gastroenteritis by emerging norovirus GII.2[P16] in a kindergarten in Kota Kinabalu, Malaysian Borneo

Abstract

outbreaks of diarrhea in kindergartens are underreported and frequently go unnoticed in developing countries. to better understand the etiology this study was performed during an outbreak of diarrhea in a kindergarten in Sabah, Malaysia. outbreak investigation was performed according to the standard procedures. In this outbreak a total of 34 (36.5%) children and 4 (30.8%) teachers suffered from gastroenteritis. Stool samples from seven children and 13 teachers were tested for rotavirus and norovirus. During the investigation stool samples were collected and sent in cold chain to the laboratory. the samples were subjected to rotavirus enzyme linked immunosorbent assay, and reverse transcription pcR for norovirus. All samples were negative for rotavirus but positive for norovirus. to determine the genogroup and genotype of norovirus, nucleotide sequencing of the amplicons was performed. All norovirus from the outbreak was of genotype GII.2[16]. To determine the relatedness of the strains phylogenetic analysis was done using neighbor-joining method. phylogenetically these strains were highly related to GII.2[P16] noroviruses from China and Japan. This study provided evidence that a diarrheal outbreak in a kindergarten was caused by GII.2[P16] norovirus which is an emerging strain in east Asia and europe.Norovirus is highly infectious and is transmitted primarily from person-to-person through the fecal-oral route within closed settings such as schools, cruise ships, hospitals, childcare facilities and aged-care institutions 1,2 . Currently this virus is divided into ten genogroups GI-GX based on the genetic differences of the capsid protein 3 . GI and GII are primarily responsible for human infection 4 . GII.4 causes most infections worldwide, followed by GII.3 or GII.6 and then other genotypes in varying proportions 5-10 . Although norovirus infection is an important cause of diarrhea in developing countries, outbreaks are under reported and frequently go unnoticed. In Kota Kinabalu, the capital of Sabah state in Malaysia, only two diarrheal outbreaks, including this one, have been reported in kindergartens between 2014 and June 2018. However, kindergartens are vulnerable to norovirus outbreaks: in Pudong district, Shanghai, China, 29 of 60 reported norovirus outbreaks occurred in kindergartens over a period of one year 11 . Therefore, understanding the epidemic situation, relationship with other strains, evolution, genetic variants and the genotype distribution of norovirus during outbreaks is important to determine the best strains to include in future norovirus vaccines. Global surveillance data indicates that several norovirus genotypes are responsible for outbreak but majority are caused by GII.4 12,13 . Since 2002, new GII.4 variants have emerged every two to three years, resulting in epidemics and global pandemics 13 . To emerge and persist in human population norovirus generate diverse strains by point mutations and recombination 14 . However, recent outbreaks of norovirus particularly in Asia and Europe wer...

Norovirus: Facts and Reflections from Past, Present, and Future

“…Human-to-human transmission of NoV is common, mainly by the fecal-oral route (particularly for the epidemic strain GII.4); although, spread may be enhanced by episodes of vomiting [59]. NoV can efficiently survive in the environment and resists freezing temperatures, heating to 60 • C, and disinfection with chlorine or alcohol-facilitating contamination of food, water, and inanimate surfaces [60]-eventually leading to outbreaks, especially in close settings as daycare centers, schools [46,61], hospitals, military camps, and cruise ships [41,62], among others. NoV is highly contagious due to its very low infectious dose; a single particle has an infection probability of 50%, although a doseresponse relationship has been noted, in which individuals exposed to higher numbers of viruses experience a higher infectious rate [34,47,61,63].…”

Isolation, identification, and whole genome sequence analysis of the alginate-degrading bacterium Cobetia sp. cqz5-12

“…(c) The construction of a phylogenetic tree using MEGA 7.0 software. The analysis of the self-expansion was performed after 1,000 times of repeated sampling by the Neighbor-joining method 53 .…”

What is the Potential Cause for the Predominance of GII.2[P16] Norovirus in Acute Gastroenteritis Outbreaks in China?

“…GII genogroup viruses are the most commonly detected in humans; they can be further divided into 27 confirmed genotypes and 37 P types. From the mid-1990s to 2014, GII.4 genotype and its new variants have caused about 70%−80% of all NoVassociated AGE outbreaks worldwide (3) (4)(5)(6). The occurrence of GII.2[P16] from sporadic to large-scale outbreaks suggested that the reemergence and sudden epidemic may be related to the change of viral biological properties, which led to stronger transmissive and infective ability.…”

“…GII.2[P16] recombinant NoV first appeared in Japan in 2008 and caused AGE outbreaks in Osaka at that time and then was occasionally detected in sporadic cases. In 2016, GII.2[P16] NoV reemerged in Guangdong Province, China, and rapidly became the main epidemic strain in Asian countries ( 4 - 6 ). The occurrence of GII.2[P16] from sporadic to large-scale outbreaks suggested that the reemergence and sudden epidemic may be related to the change of viral biological properties, which led to stronger transmissive and infective ability.…”