Cause Of Acute Gastroenteritis Research Articles

Global age distribution of pediatric norovirus cases

Norovirus is increasingly recognized as a major cause of acute gastroenteritis among children <5 years of age. We searched for publications that reported detailed age distributions of pediatric norovirus cases, and assessed associations between age distribution and socio-demographic factors to identify the most critical age periods to prevent norovirus cases among young children. Approximately 70% of pediatric norovirus cases occurred between 6 and 23 months of age. A younger age distribution was found in lower income countries and inpatient settings. These findings suggest that a norovirus immunization schedule completed by 6 months could have the potential to prevent about 85% of pediatric cases, while a vaccine delivered at 12 months of age would only have the potential to prevent about 50% of pediatric cases. With a younger age distribution in lower income settings, early prevention would be even more critical.

Changes in the distribution of lineage constellations of G2P[4] Rotavirus A strains detected in Japan over 32 years (1980–2011)

Rotavirus A (RVA) is a leading cause of acute gastroenteritis in young children worldwide. Most human RVA strains are classified into three major genotype constellations: Wa-like, DS-1-like and AU-1-like. The evolution of G2P[4] strains possessing the DS-1-like genetic background was described in a few recent studies. However, the strains analyzed in these studies were almost exclusively the ones detected after 2000. In recognition of the scarcity of G2P[4] strains detected before 2000 for which whole genome information was available, this study was undertaken to characterize 19 Japanese G2P[4] strains detected between 1983 and 1990 (14 strains) and between 2001 and 2011 (5 strains), and to compare them with 131 G2P[4] strains from across the world. The Japanese strains along with the strains elsewhere in the world underwent stepwise changes from lineage I to IVa in 5 genes (the VP7, VP4, VP2, NSP1 and NSP5 genes) and from lineage I to V in 6 genes (the VP6, VP1, VP3, NSP2, NSP3 and NSP4 genes). Furthermore, G2P[4] strains detected after 2004 appeared to have undergone further intragenotype reassortment, resulting in the emergence of lineage V in the VP7 gene, and VI and VII in the VP3 and NSP4 genes. The time of the most recent common ancestor (tMRCA) for the emergent lineages VI and VII was estimated to be around the early 2000s. However, the year when the ancestor of the emergent lineages diverged from that of the rest of the lineages in the respective genes preceded the tMRCA 80–90years. The origin of the emergent lineages is likely to be human RVA strains possessing genotypes other than G2P[4], and not RVA strains of an animal origin. In conclusion, stepwise changes in lineages imparted new genomic constellations to G2P[4] strains, which appears to have contributed to their successful spread across the globe, most notably since 2004.

Application of salivary antibody immunoassays for the detection of incident infections with Norwalk virus in a group of volunteers

Norovirus infection is the most common cause of acute gastroenteritis in developed countries. Developing an assay based on a non-invasive biomarker for detecting incident norovirus infections could improve disease surveillance and epidemiological investigations. This project involved analysis of IgA and IgG norovirus-specific antibody responses in saliva samples from a Norwalk virus (Genogroup I, genotype 1 norovirus) challenge study involving infected and symptomatic, and non-infected asymptomatic individuals. Saliva was collected at the challenge, and two weeks and 40days post-challenge. Samples were analyzed using the Luminex fluorometric and Meso Scale Discovery (MSD) electrochemiluminescence immunoassays. Recombinant P domains of Norwalk virus capsid protein, as well as similar recombinant proteins of two genogroup II noroviruses (VA387 and VA207) were used as antigens. Immunoconversions were defined as >4-fold increase in antibody responses to the norovirus antigens. Various sample pre-treatment options, buffers, saliva dilution ratios, and data adjustment approaches to control for sample-to-sample variability in saliva composition were compared using the Luminex assay. The results suggest that adjusting responses to the norovirus antigens for responses to the protein purification tag, glutathione-S-transferase (GST), significantly improved the odds of producing a correct immunoconversion test result. IgG-based tests were more accurate compared to IgA-based tests. At optimal conditions, both Luminex and MSD assays for Norwalk-specific IgG antibodies correctly identified all infected and non-infected individuals. There was no evidence of cross-reactivity of anti-Norwalk virus antibodies with genogroup II noroviruses. These results suggest that salivary antibody responses can be used for the detection of incident infections with Norwalk virus in prospective surveys.

Group a rotavirus and norovirus genotypes circulating in the northeastern Brazil in the post-monovalent vaccination era.

Group A rotaviruses (RVA) and noroviruses (NoV) are the leading cause of acute gastroenteritis (AGE) worldwide. Childhood diarrhea deaths and hospital admissions have declined since the introduction of the monovalent (G1P[8]) vaccine (Rotarix(®) [RV1]) in the National Immunization Program in Brazil in 2006. This study aims to investigate the epidemiological profile of NoV and RVA infections from children with AGE in the Northeastern region of Brazil in the post vaccine season. Two-hundred fecal samples collected from children up to 10 years old in Fortaleza, Ceará between 2008-2009 were screened for the presence of RVA and NoV. Positive samples were genotyped and sequenced. The RVA screening revealed 12% prevalence and all RVA strains belonged to G2P[4] genotype. Phylogenetic analysis based on the 11 RVA genome segments sequenced from eight samples revealed a DS-1-like genotype constellation: I2-R2-C2-M2-A2-N2-T2-E2-H2. For NoV screening, the prevalence observed was 17% and the following genotypes were detected: GII.4 (59%), GII.12 (17%), GII.6 (9%), GII.3 (6%), and GII.? (9%). At least four different NoVs genotypes and two RVA G2P[4] variants were identified circulating in the Northeastern region of Brazil. RVA phylogenetic analysis suggests that the RVA G2P[4] strains might have originated from intragenogroup reassortment events. Whether the genetic modifications observed in these contemporary G2P[4] RVA strains may impact the long-term effectiveness of the current vaccination programs remains to be explored. These data reinforce the importance of surveillance for monitoring the emergence of new strains of RVA and NoV and their impact on cases of acute gastroenteritis.

Global occurrence and emission of rotaviruses to surface waters.

Group A rotaviruses (RV) are the major cause of acute gastroenteritis in infants and young children globally. Waterborne transmission of RV and the presence of RV in water sources are of major public health importance. In this paper, we present the Global Waterborne Pathogen model for RV (GloWPa-Rota model) to estimate the global distribution of RV emissions to surface water. To our knowledge, this is the first model to do so. We review the literature to estimate three RV specific variables for the model: incidence, excretion rate and removal during wastewater treatment. We estimate total global RV emissions to be 2 × 1018 viral particles/grid/year, of which 87% is produced by the urban population. Hotspot regions with high RV emissions are urban areas in densely populated parts of the world, such as Bangladesh and Nigeria, while low emissions are found in rural areas in North Russia and the Australian desert. Even for industrialized regions with high population density and without tertiary treatment, such as the UK, substantial emissions are estimated. Modeling exercises like the one presented in this paper provide unique opportunities to further study these emissions to surface water, their sources and scenarios for improved management.

Rapid, Active Surveillance for Medically Attended Acute Gastroenteritis and Norovirus Infection in a Managed Care Environment

Background/Aims: Norovirus is the leading cause of acute gastroenteritis in the United States and is the leading cause of medically attended acute gastroenteritis (MAAGE) among children younger than five years of age. Our primary goal is to describe the community incidence of MAAGE and the proportion of MAAGE encounters due to norovirus within the membership population of Kaiser Permanente Northwest (KPNW). Our secondary goal is to describe transmission of norovirus within households.

Genomic characterization of uncommon human G3P[6] rotavirus strains causing diarrhea in children in Italy in 2009

Group A rotaviruses (RVA) are the leading cause of acute gastroenteritis in young children, causing up to 450,000 deaths worldwide, mostly in developing countries. Most of RVA human infections in developed countries are related to five major G/P combinations: G1P[8], G2P[4], G3P[8], G4P[8] and G9P[8]. During the surveillance activity of RotaNet-Italy, three uncommon G3P[6] RVA strains, designated as RVA/Human-wt/ITA/NA01/2009/G3P[6], RVA/Human-wt/ITA/NA06/2009/G3P[6], and RVA/Human-wt/ITA/NA19/2009/G3P[6], were identified in the stools of children with diarrhea hospitalized in Southern Italy in 2009. Samples NA01, NA06 and NA19 were characterized as genotype G3P[6]. To investigate the three strains further, partial sequencing of the eleven genomic segments was performed. RVA strains NA01, NA06 and NA19 were found to share the rare genotype constellation: G3-P[6]-I2-R2-C2-M2-A2-N2-T2-E2-H2, which had not been reported previously in continental Italy. The phylogenetic analysis of the eleven genomic segments showed no evidence of zoonosis or inter-species reassortment at the origin of the Italian G3P[6] strains, indicating that they possessed DS-1-like genomic constellations similar to those detected previously in human cases in Africa and Europe. The analysis of the hypervariable regions of VP7 and VP4 (VP8*) revealed high amino acid identity between the Italian G3P[6] RVA strains involved in this study.

Evolution of human G4P[8] group A rotavirus strains circulating in Italy in 2013

Group A rotaviruses (RVA) are the leading cause of acute gastroenteritis in young (<5 years of age) children, causing up to 450.000 deaths worldwide, mostly in developing countries. VP7 (G-type) and VP4 (P-type) genotypes are the basis for the binary RVA classification. Although at least 27 G-types and 37 P-types of rotavirus are presently known, most RVA infections in humans worldwide are associated with the five major G/P combinations G1P[8], G2P[4], G3P[8], G4P[8] and G9P[8].During RVA gastroenteritis surveillance in Italy, a total of 1112 samples collected from children hospitalized with acute gastroenteritis in 2013 were RVA positive and were genotyped following standardized protocols from the EuroRotaNet. Most strains analyzed belonged to the five major human genotypes. Among these common strains, 22 G4P[8] RVA strains from different Italian regions were subjected to nucleotide sequencing of their VP4, VP6, VP7 and NSP4 genes to investigate their evolution.The phylogenetic analysis showed that the Italian strains belonged to lineage G4-I for VP7 and to lineage P[8]-III for VP4, in line with the modern G4P[8] RVA strains detected in children worldwide. The phylogenetic trees revealed high degrees of nucleotide identity between the RVA strains involved in this study and G4P[8] strains detected previously in Europe, Asia and Africa, but also demonstrated at least three separate evolution clusters within the same lineage.Based on the amino acid sequences deduced for their hypervariable regions, both the VP7 and VP8* proteins of the Italian G4P[8] RVA strains presented amino acid substitutions near known neutralizing epitopes.

Outbreak of Gastroenteritis in Adults Due to Rotavirus Genotype G12P[8

Rotavirus infection in adults is poorly understood and few rotavirus outbreaks among US adults have been reported in the literature. We describe an outbreak due to genotype G12P[8] rotavirus among medical students, faculty, and guests who attended a formal dinner event in April 2013. A web-based questionnaire was distributed to event attendees to collect symptom and exposure data. A clinical case was defined as a person who developed diarrhea after attending the formal event. A laboratory-confirmed case was defined as a clinical case who attended the formal event, with rotavirus detected in stool by enzyme immunoassay or reverse transcription-polymerase chain reaction (RT-PCR) assay. Among 334 dinner attendees, 136 (41%) completed the web-based questionnaire; 58 (43%) respondents reported illness. Symptom onset ranged from 1 to 8 days, with peak onset 3 days after the event. In addition to diarrhea, predominant symptoms included fever (91%), abdominal pain (84%), and vomiting (49%). The median duration of illness was 2.5 days. Thirteen (22%) of 58 cases sought medical attention; none were hospitalized. Analysis of food exposures among questionnaire respondents did not identify significant associations between any specific food or drink item and illness. Stool specimens were negative for bacterial pathogens by culture and negative for norovirus by RT-PCR assay; 4 specimens were positive for rotavirus by enzyme immunoassay or PCR. G12P[8]-R1-C1-M1-A1-N1-T1-E1-H1 was identified as the causative full-genome genotype. Rotavirus outbreaks can occur among adults, including young adults. Health professionals should consider rotavirus as a cause of acute gastroenteritis in adults.

Molecular chaperone Hsp90 is a therapeutic target for noroviruses.

ABSTRACTHuman noroviruses (HuNoV) are a significant cause of acute gastroenteritis in the developed world, and yet our understanding of the molecular pathways involved in norovirus replication and pathogenesis has been limited by the inability to efficiently culture these viruses in the laboratory. Using the murine norovirus (MNV) model, we have recently identified a network of host factors that interact with the 5′ and 3′ extremities of the norovirus RNA genome. In addition to a number of well-known cellular RNA binding proteins, the molecular chaperone Hsp90 was identified as a component of the ribonucleoprotein complex. Here, we show that the inhibition of Hsp90 activity negatively impacts norovirus replication in cell culture. Small-molecule-mediated inhibition of Hsp90 activity using 17-DMAG (17-dimethylaminoethylamino-17-demethoxygeldanamycin) revealed that Hsp90 plays a pleiotropic role in the norovirus life cycle but that the stability of the viral capsid protein is integrally linked to Hsp90 activity. Furthermore, we demonstrate that both the MNV-1 and the HuNoV capsid proteins require Hsp90 activity for their stability and that targeting Hsp90 in vivo can significantly reduce virus replication. In summary, we demonstrate that targeting cellular proteostasis can inhibit norovirus replication, identifying a potential novel therapeutic target for the treatment of norovirus infections.IMPORTANCE HuNoV are a major cause of acute gastroenteritis around the world. RNA viruses, including noroviruses, rely heavily on host cell proteins and pathways for all aspects of their life cycle. Here, we identify one such protein, the molecular chaperone Hsp90, as an important factor required during the norovirus life cycle. We demonstrate that both murine and human noroviruses require the activity of Hsp90 for the stability of their capsid proteins. Furthermore, we demonstrate that targeting Hsp90 activity in vivo using small molecule inhibitors also reduces infectious virus production. Given the considerable interest in the development of Hsp90 inhibitors for use in cancer therapeutics, we identify here a new target that could be explored for the development of antiviral strategies to control norovirus outbreaks and treat chronic norovirus infection in immunosuppressed patients.

English

Diarrheagenic Escherichia coli (DEC) is one of the main causes of acute gastroenteritis in infants and young children in sub-Saharan Africa. This study investigated the prevalence, serotypes and antibiotic resistance patterns of enteropathogenic E. coli (EPEC) and enterohemorrhagic E. coli (EHEC) among diarrheal children in rural Burkina Faso. Stool specimens were collected from 280 children under 5 years of age visiting hospital due to acute diarrhea between July 2009 and June 2010. E. coli isolates were subjected to serotyping and their susceptibility to 9 antimicrobial agents was determined by the disc diffusion method. Sixty patients (21.4%) had DEC of which 54 strains (19.3%) belonged to EPEC O serogroups and six (2.1%) to EHEC O157 serotype. A higher rate of EPEC (91.6%) was found in patients aged less than 2 years. More than 70% of E. coli isolates were resistant to ampicillin, amoxicillin/clavulanic acid, tetracycline, trimethoprim-sulfamethoxazole and 28.3% to nalidixic acid. Twenty three (38.3%) of the isolated E. coli were ESBL producers with higher prevalence (56.5%) in children under 12 months of age. This study stresses the public health importance of diarrheal E. coli with serotypes of EPEC and EHEC O157 and their resistance to antibiotics in Burkina Faso. Key words: Escherichia coli serotypes, antibiotics resistance, diarrheal children, Burkina Faso.

Determination of cut-off cycle threshold values in routine RT-PCR assays to assist differential diagnosis of norovirus in children hospitalized for acute gastroenteritis.

Norovirus (NV) is an important cause of acute gastroenteritis in children, but is also frequently detected in asymptomatic children, which complicates the interpretation of NV detection results in both the clinical setting and population prevalence studies. A total of 807 faecal samples from children aged <5 years hospitalized for acute gastroenteritis were collected in Thai Binh, Vietnam, from January 2011 to September 2012. Real-time RT-PCR was used to detect and quantify NV-RNA in clinical samples. A bimodal distribution of cycle threshold (Ct) values was observed in which the lower peak was assumed to represent cases for which NV was the causal agent of diarrhoea, whereas the higher peak was assumed to represent cases involving an alternative pathogen other than NV. Under these assumptions, we applied finite-mixture modelling to estimate a threshold of Ct <21·36 (95% confidence interval 20·29-22·46) to distinguish NV-positive patients for which NV was the likely cause of diarrhoea. We evaluated the validity of the threshold through comparisons with NV antigen ELISA results, and comparisons of Ct values in patients co-infected with rotavirus. We conclude that the use of an appropriate cut-off value in the interpretation of NV real-time RT-PCR results may improve differential diagnosis of enteric infections, and could contribute to improved estimates of the burden of NV disease.

A case report on transitory histamine intolerance from strawberry intake in a 15 month old child with acute gastroenteritis

Background Histamine is a vasoactive amine found in different foods. Di-amine oxidase (DAO) released from apical cells of intestinal mucosa is the responsible metabolizing enzyme for ingested histamine. Histamine excess because of DAO reduced or inhibited activity may mimic an allergic symptomatology, often misleading to food allergy diagnosis instead of histamine intolerance. Viruses, as the main cause of acute gastroenteritis in children, induce apical cell death, lower DAO production levels and increase the intestinal permeability owing to direct and indirect virus -host interactions.

Molecular characterization of group A rotavirus strains detected in children with diarrhea admitted to Nigerian hospitals in 2013.

Group A rotaviruses (RVA) are the leading cause of acute gastroenteritis (AGE) in children worldwide and cause up to 455,000 deaths annually, mostly in developing countries. During 2013, 66 RVAs from children with AGE admitted to four Nigerian hospitals were investigated. The G3P[6], G1P[8] and G2P[4] genotypes predominated. The VP7 and/or VP4 genes of 18 G3P[6]/[8]/[4], six G2P[4], three G12P[8]/[4], and two G1P[8] RVA strains were sequenced. The G3P[6] strains belonged to lineage G3-III and were different from G3 strains widespread in Asia. Phylogenetic analysis revealed substantial sequence conservation, suggesting continuing evolution and genomic reassortment but no zoonotic RVA transmission from animals.

The prevalence of norovirus, astrovirus and adenovirus infections among hospitalised children with acute gastroenteritis in Porto Velho, state of Rondônia, western Brazilian Amazon.

Although viruses are well-established causes of acute gastroenteritis, few data on the circulation of these pathogens in Porto Velho, state of Rondônia, Brazil, are available. Thus, faecal samples from hospitalised diarrhoeic children, under six years of age, were collected and tested for the presence of norovirus (NoV), adenovirus (AdV) and astrovirus (AstV) from February 2010-February 2012. Specimens were screened by reverse-transcription polymerase chain reaction and viruses were found in 10.7% (63/591) of the cases. NoV, AdV and AstV were detected in 7.8%, 2% and 0.8% of the samples, respectively. NoV infection was observed at all ages and was most prevalent in zero-18-month-old children (84.7%; p = 0.002). A higher incidence of NoV was detected from February-April 2010, when it was found in 52.2% of the cases. Co-infections involving these viruses, rotavirus and enteropathogenic bacteria were detected in 44.4% (28/63) of the children with viral diarrhoea. Nosocomial infections were demonstrated in 28.6% (18/63) of the cases in which viruses were detected. The present paper reports, for the first time, the circulation of NoV and AstV among the paediatric population of Porto Velho and it contributes to our understanding of the roles of these pathogens in gastrointestinal infections.

Innate Susceptibility to Norovirus Infections Influenced by FUT2 Genotype in a United States Pediatric Population.

Norovirus is a leading cause of acute gastroenteritis (AGE). Noroviruses bind to gut histo-blood group antigens (HBGAs), but only 70%-80% of individuals have a functional copy of the FUT2 ("secretor") gene required for gut HBGA expression; these individuals are known as "secretors." Susceptibility to some noroviruses depends on FUT2 secretor status, but the population impact of this association is not established. From December 2011 to November 2012, active AGE surveillance was performed at 6 geographically diverse pediatric sites in the United States. Case patients aged <5 years were recruited from emergency departments and inpatient units; age-matched healthy controls were recruited at well-child visits. Salivary DNA was collected to determine secretor status and genetic ancestry. Stool was tested for norovirus by real-time reverse transcription polymerase chain reaction. Norovirus genotype was then determined by sequencing. Norovirus was detected in 302 of 1465 (21%) AGE cases and 52 of 826 (6%) healthy controls. Norovirus AGE cases were 2.8-fold more likely than norovirus-negative controls to be secretors (P < .001) in a logistic regression model adjusted for ancestry, age, site, and health insurance. Secretors comprised all 155 cases and 21 asymptomatic infections with the most prevalent norovirus, GII.4. Control children of Meso-American ancestry were more likely than children of European or African ancestry to be secretors (96% vs 74%; P < .001). FUT2 status is associated with norovirus infection and varies by ancestry. GII.4 norovirus exclusively infected secretors. These findings are important to norovirus vaccine trials and design of agents that may block norovirus-HBGA binding.

The burden of norovirus disease in children in the European Union.

Noroviruses (NoVs) are the leading cause of acute gastroenteritis across all age groups. Because a vaccine is in clinical development, burden of disease data are required to guide the eventual introduction of this vaccine. In this study, we estimate the burden of NoV disease in children less than 5 years of age in the European Union (EU). We carried out a literature search using PubMed to identify studies providing incidence or prevalence data for NoV disease in the EU. We applied the pooled average NoV incidence and prevalence rates to the EU population less than 5 years of age to obtain the annual number of NoV illnesses, medical visits, hospitalizations and deaths occurring in the EU among children younger than 5 years. Data from 12 studies were included. We estimate that NoV infection may cause up to 5.7 million illnesses in the community, 800,000 medical visits, 53,000 hospitalizations and 102 deaths every year in children younger than 5 years in the EU. The burden of NoV disease in children in the EU is substantial, and will grow in relative importance as rotavirus (RV) vaccines are rolled out in the EU. This burden of disease is comparable with the burden of RV disease in the EU before RV vaccine introduction. More country-specific studies are needed to better assess this burden and guide the potential introduction of a vaccine against NoV at the national level.

Human rotavirus group a serotypes causing gastroenteritis in children less than 5 years and HIV-infected adults in Viwandani slum, Nairobi.

Rotavirus remains a leading cause of acute gastroenteritis in children worldwide with an estimated 2000 deaths each day in developing countries. Due to HIV/AIDS scourge in Kenya, it is possible that rotavirus-related gastroenteritis has been aggravated in adults. The Global Alliance for Immunizations has ranked rotavirus infection a priority for vaccine, and, to ensure its success, there is a need to document the local strain(s) circulating in different regions. A cross-sectional study was conducted to document human rotavirus group A serotypes in children below 5 years and HIV-infected adults in Viwandani slum in Nairobi, Kenya. A total of 260 (128 from children and 132 from HIV infected adults) fecal specimen samples were analyzed from August 2012 to July 2013. Screening for rotavirus was done by antigen based enzyme immune-sorbent assay (ELISA), Polyacrylamide gel electrophoresis (PAGE) was used to detect rotavirus electropherotypes and finally genotyping was done by RT-PCR using genotype-specific primer sets targeting VP4 and VP7 genes. Rotavirus was detected in 23% and 8% of children and adult, respectively. Prevalence was high in children of < 2 years and adults of > 48 years. Long electropherotypes accounted for 80% and 60% while short electropherotypes accounted for 20% and 40% in children and adult, respectively. The common globally distributed strains, G1 and G3, accounted for 60% detections while the unusual G9 strain accounted for 80% infection in adults. G1P[8] was the common genotypic combination in children, accounting for 40% infection, whereas G9 [P8] accounted for 60% of the infections in adults. This study shows the existence of strain diversity between rotavirus circulating in children and adults within this study group. It further shows that as currently constituted, the 2 vaccines recommended for rotavirus would cover the circulating strain in Viwandani slum. Finally, there is a need for continuous rotavirus strain surveillance in children and a further focus on HIV infected adults.

Identification and Antimicrobial Susceptibility Profile of Salmonella Isolated from Selected Dairy Farms, Abattoir and Humans at Asella Town, Ethiopia

Salmonella is one of the most common causes of food-borne diarrheal disease in human as well as animals. It is leading causes of acute gastroenteritis when ingested in contaminated foods, including meat and dairy products. Moreover, the emergence of multiple-resistant (MDR) isolates is increasing in human and veterinary medicines. Therefore, this cross-sectional study aims at isolation, identification and antibiogram of Salmonella from selected dairy cattle farms, abattoir and in contact humans in both dairy farms and abattoir of Asella, Ethiopia. We collected 185 samples from abattoir (n=94) and dairy farms (n=91), which were isolated and identified according to ISO-6579, 2002. The overall proportion of Salmonella was 6.5% (12/185) (dairy farms n=4, 4.4% and abattoir n=8, 8.5%). Antibiogram of isolated Salmonella was also evaluated against ten commonly used antibiotics in both humans and veterinary medicines to treat salmonellosis by using the Kibry Bauer disk diffusion method. All isolates (100%, n=12) were susceptible to ciprofloxacin and gentamycin followed by 91.7%, 75%, 66.7%, 58.3 and 50% of the isolates were susceptible to sulfamethoxazole-trimethoprim, chloramphenicol, kanamycin, nalidixic acid and streptomycin, respectively. However, cefoxitin showed the highest resistance (66.7%) followed by ampicillin and amoxicillin (58.3% each). Moreover, 50% of the isolates were resistant to two or more of the tested antimicrobial agents. The highest MDR was seen on polled hand swabs from abattoir, resistance to eight antimicrobials (80%, n=8/10) with the combination of cefoxitin, ampicillin, amoxicillin and streptomycin being more frequent. High proportion of Salmonella was isolated from abattoir sample than dairy farms. These isolate developed MDR to commonly prescribed antimicrobial agents in the study area. Hence, strict hygienic management in the farm and abattoir as well as rational use of antimicrobials should be practised to circumvent the further development of antimicrobial resistance.

Norovirus.

Norovirus, an RNA virus of the family Caliciviridae, is a human enteric pathogen that causes substantial morbidity across both health care and community settings. Several factors enhance the transmissibility of norovirus, including the small inoculum required to produce infection (<100 viral particles), prolonged viral shedding, and its ability to survive in the environment. In this review, we describe the basic virology and immunology of noroviruses, the clinical disease resulting from infection and its diagnosis and management, as well as host and pathogen factors that complicate vaccine development. Additionally, we discuss overall epidemiology, infection control strategies, and global reporting efforts aimed at controlling this worldwide cause of acute gastroenteritis. Prompt implementation of infection control measures remains the mainstay of norovirus outbreak management.