Norovirus, the principal cause of viral diarrhea in two regions of Colombia

Univ. Sci. 2015, Vol. 20 (1): 107-115 doi: 10.11144/Javeriana.SC20-1.npcv Freely available on line original article Norovirus, the principal cause of viral diarrhea in two regions of Colombia Fernández KP1, Ulloa JC1, Meneses M1, Matiz LF1, Gutiérrez MF1 Abstract Rotavirus is recognized worldwide as the main and most important viral pathogen associated with diarrhea in children while norovirus is considered the second cause of epidemic diarrhea in developed countries. Here, we present a comparative study on the prevalence of rotavirus and norovirus in two regions of Colombia: Chocó and Cundinamarca. Five hundred and thirty stool samples were collected; 330 in Cundinamarca and 200 in Chocó. In the sample set from Chocó, 6 % of the samples presented rotavirus and 8 % norovirus; meanwhile, 9.7 % of the samples from Bogotá presented rotavirus and 9 % norovirus. These results show that, in some regions of Colombia, the prevalence of norovirus is similar or slightly higher than rotavirus. This is a tendency that should be examined in other non-developed countries as it suggests that the presence of norovirus should also be under surveillance. Keywords: Norovirus; Rotavirus; diarrhea; Chocó; Cundinamarca. Introduction Edited by Alberto Acosta 1. Laboratorio de Virología, Universidad Javeriana, Bogotá, Colombia Received: 14-05-2014 Accepted: 05-08-2014 Published on line: 29-09-2014 Citation: Fernández KP, Ulloa JC, Meneses M, Matiz LF, Gutiérrez MF (2015) Norovirus, the principal cause of viral diarrhea in two regions of Colombia. Universitas Scientiarum 20(1): 107-115 doi: 10.11144/Javeriana.SC20-1.npcv Funding: Banco de la República. Electronic supplementary material: Suppl. 1. Rotaviruses (RV) are non-enveloped virions, with an 11-segmented dsRNA and a triple layer concentric protein capsid. Norovirus (NV), meanwhile, is positive RNA strand, non-enveloped as well and singled capsid virus (Guerrero et al. 2000, Hardy 2005). Diarrhea is considered the second leading cause of deaths in children under 5 years old and enteric viruses are the most important etiological agents of acute diarrhea disease (ADD) in children all around the world. Within these, the Group A of Rotavirus (RV) has been recognized as the most prevalent, but other viruses such as astrovirus, enteric adenovirus and norovirus (NV), have also been reported (Wilhelmi et al. 2003, Meraabi et al. 2011). Universitas Scientiarum, Journal of the Faculty of Sciences, Pontificia Universidad Javeriana, is licensed under the Creative Commons 2.5 of Colombia: Attribution - Noncommercial - No Derivative Works. 108 NV is known to be associated with epidemic behaviors affecting people in developed countries dwelling crowded places such as schools, nursing homes, military centers, but in developing countries the same virus has been associated with sporadic diarrhea (Wu et al. 2008, Donaldson et al. 2008, Harris et al. 2010,Wiegering et al. 2011). Therefore, NV has been considered the most important cause of epidemic gastroenteritis, the second most important cause of endemic gastroenteritis in all age groups worldwide and a common cause of sporadic nonbacterial gastroenteritis in individuals of all ages. The overall clinical burden caused by NV infection is thought to be milder than the one given by RV (Beersma et al. 2009, Yanga et al. 2010) because RV infections are known to be more severe and more often associated with a complicated course (Donaldson et al. 2008, Ciarlet & Schödel 2009, Lin et al. 2010, Meraabi et al. 2011, Rivera et al. 2011, Wiegering et al. 2011, Solano-Aguilar et al. 2012) One of the main reasons of the important prevalence of those viruses is their route of infection. The fecal–oral route is the common route of transmission, typically through food, water or contaminated surfaces; but person-to-person transmission, by direct contact or exposure to aerosols from vomit, are also important (Wilhelmi et al. 2003, Wu et al. 2008, Ribes & Buesa 2010, Wiegering et al. 2011, Lopman et al. 2012). High concentrations of these viral agents are introduced into the environment through the discharge of either treated or untreated sewage (Lin et al. 2010, Blanco et al. 2012). In Colombia, our group has performed for over 10 years, two studies looking for viral agents associated with ADD. In both, prevalence’s of NV were similar to RVs. In the year 2000, we tested 300 diarrheic stool samples and found 10 % of NV and 13 % of RV in children with less than 5 years of age in FacatativáCundinamarca, Colombia (Gutierrez et al. 2006). Later in 2003, we found 8 % and 10 % for RV and NV respectively in fecal samples of children coming from Quibdó, Chocó. Therefore, the prevalence of NV could outperform the well-known prevalence of RV. In order to show that NV is associated with sporadic and endemic diarrhea and exhibits a behavior which may be even greater than RVs in children, new set of samples were collected from the same Colombian regions: Cundinamarca and Chocó. Universitas Scientiarum Vol. 20 (1): 107-115 Norovirus first etiological agent in Colombia The aim of this study was to evaluate the presence of RV and NV in a new set of samples collected from the regions already described. Material and methods Sample collection A total of 530 children under 5 years of age from two Colombian regions (one located in Bogotá, Cundinamarca, capital of Colombia and the other one in Quibdó, a small city of Chocó, close to the pacific coast in the northwest area of the country) were recruited to participate in a prospective, observational study. For the inclusion of the children in the diarrhea group the subjects must meet the criteria stated by the World Health Organization (WHO) for diarrhea as liquid or reduced consistency of the stool with an increased frequency of >3 times in 24 h for a period of less than 2 weeks. Healthy children, from the same locations, were those without any clinical signs of diarrhea disease, vomiting or fever and with normal stool consistency before the beginning of the study. After obtaining informed parental consent, stool specimens and demographic information (including age, gender and RV vaccine) were collected. Fecal samples were collected, immediately refrigerated at 4 °C and transported to the Virology Laboratory at the Pontificia Universidad Javeriana. Upon receipt, samples were separated in two aliquots. One aliquot was conserved at -80 °C and the other one was used for the RNA extraction and subsequent viral identification. Viral detection RV and NV were detected by conventional RT-PCR. Initially, viral RNA was extracted from 10 % stool suspension in PBS by the use of QIAamp® Viral RNA Mini kit (Qiagen, Courtaboeuf, France) according to the instructions provided by the manufacturer. Then, for the retrotranscription step, five microliters of RNA were mixed with 1 pmol of antisense primer incubated at 95 °C x 5 min and chilled immediately on ice. A mixture of Buffer 5x-RT, DTT 0.1 M, d (...truncated)