Serotyping of group A rotaviruses in Egyptian neonates and infants less than 1 year old with acute diarrhea

Persistence of G10P[11] neonatal rotavirus infections in southern India

Background:

Neonatal rotavirus infections are predominantly caused by distinct genotypes restricted to this age-group and are mostly asymptomatic.

Method:

Stool samples from neonates admitted for >48 h in neonatal intensive care units (NICUs) in Vellore (2014–2015) and Chennai (2015–2016) in southern India, and from neonates born at hospitals in Vellore but not admitted to NICUs (2015–2016) were tested for rotavirus by ELISA and genotyped by hemi-nested RT-PCR.

Results:

Of 791 neonates, 150 and 336 were recruited from Vellore and Chennai NICUs, and 305 were born in five hospitals in Vellore. Positivity rates in the three settings were 49.3% (74/150), 29.5% (99/336) and 54% (164/305), respectively. G10P[11] was the commonly identified genotype in 87.8% (65/74), 94.9% (94/99) and 98.2% (161/164) of the neonates in Vellore and Chennai NICUs, and those born at Vellore hospitals, respectively. Neonates delivered by lower segment cesarian section (LSCS) at Vellore hospitals, not admitted to NICUs, had a significantly higher odds of acquiring rotavirus infection compared to those delivered vaginally [p = 0.002, OR = 2.4 (1.4–4.3)].

Conclusions:

This report demonstrates the persistence of G10P[11] strain in Vellore and Chennai, indicating widespread neonatal G10P[11] strain in southern India and their persistence over two decades, leading to interesting questions about strain stability.

Clinical and Environmental Surveillance of Rotavirus Common Genotypes Showed High Prevalence of Common P Genotypes in Egypt

The objective of this study was to compare the prevalence of human rotavirus group A common G and P genotypes in human Egyptian stool specimens and raw sewage samples to determine the most common genotypes for future vaccine development. From 1026 stool specimens of children with acute diarrhea and using nested RT-PCR, 250 samples (24.37%) were positive for human rotavirus group A. Using multiplex RT-PCR, rotavirus common P and G genotypes were detected as 89.20% and 46.40% of the positive clinical specimens respectively. This low percentage of common G genotypes frequency may affect the efficiency of the available live attenuated oral rotavirus vaccines [Rotarix® (human rotavirus G1P[8]) and RotaTeq® (reassortant bovine-human rotavirus G1-4P[5] and G6P[8])], however the percentage of clinical specimens which were negative for common G genotypes but positive for P[8] genotype was 12.00%. From 24 positive raw sewage samples for rotavirus group A VP6 collected from Zenin and El-Gabal El-Asfar wastewater treatment plants (WWTPs), 21 samples (87.50%) were typeable for common P genotypes while 13 samples (54.17%) were typeable for common G genotypes. Phylogenetic analysis of a VP8 partial gene of 45 P-typeable clinical isolates and 20 P-typeable raw sewage samples showed high similarity to reference strains and the majority of mutations were silent and showed lower to non-significant similarity with the two vaccine strains. This finding is useful for determining the most common antigens required for future vaccine development.

Systematic review of the rotavirus infection burden in the WHO-EMRO region

Rotavirus gastroenteritis imposes a heavy burden on low- and middle-income countries. The World Health Organization defines the Eastern Mediterranean region (WHO-EMRO) as a diverse area in terms of socioeconomic status and health indicators. Rotavirus vaccination has been introduced, at least partially, in 19 out of the 22 EM countries; however, vaccine coverage remains low, and data on rotavirus disease burden is scarce.Available data on rotavirus prevalence, seasonality, vaccination status, and genotype evolution was systematically compiled following a literature review that identified 165 relevant WHO-EMRO epidemiology studies published between 1990 and 2017.Although the infectious agents responsible for acute gastroenteritis vary over time, rotavirus remained the leading cause of acute gastroenteritis in children, as seen in 76.3% of reviewed publications. Younger children (<2 years old) were at higher risk and thus increased vaccination coverage and surveillance systems are required to reduce the rotavirus gastroenteritis burden in WHO-EMRO countries.

Genotyping and Clinicoepidemiological Characterization of Rotavirus Acute Gastroenteritis in Egyptian Children

Group A rotavirus (RVA) acute gastroenteritis (AGE) is a common cause of severe childhood diarrhea. The dominant circulating RVA genotypes in a given region may vary between and within the geographic regions and from year to year. Our cross-sectional study was designed to determine the burden of RVA genotypes among children with AGE admitted to referral Children Hospital at Egypt prior to implementation of the vaccine. Stool samples with clinico-epidemiological data were collected from 92 children ≤ 3 years-old with AGE. RVA G and P typing were performed with type-specific primers. RVA was detected in 48.9% of patients. Higher rates of RVA infections, 73.3% were detected in infants < 1 year-old. Breast-fed infants were significantly fewer in RVA positive group (P = 0.0006). Non-breastfeeding was a major risk factor for RVA AGE (OR 0.3, P = 0.02). RVA diarrhea occurred mostly in autumn and winter months (55.4% and 26.6%) with a significant difference in autumn (P = 0.0005) and was associated with vomiting and dehydration (OR; 1.66, P = 0.021 & 1.4, P = 0.03). RVA genotypes G1P[8] (26.7%), G9P[8] (20%) and G3P[8] (15.6%) were accounting for 62.3% of RVA AGE. G9 was significantly associated with mucus diarrhea, than G1 or G3 which were associated with watery diarrhea (P = 0.025). Also, G9 was significantly associated with loose stool for > 5 days (P = 0.006) and 54.4% of G9 patients had severe dehydration. The diversity of RVA strains detected in Nile Delta Egypt and emergence of G9 RVA highlight the need to apply vaccines against this genotype in Egypt.

Developing an Inactivated Rotavirus Vaccine and Evaluating the Immunogenicity Against a Commercially Available Attenuated Rotavirus Vaccine Using a Mice Animal Model

There is a high demand for public immunization against Rotavirus (RV), especially in Africa. In Africa, the attenuated RV vaccination is contraindicated in patients with immune diseases and nutrition deficiency. Therefore, the inactivated RV vaccine (IRVV) could be an alternative. In this study, we aimed to develop a pentavalent-IRVV using the most circulating RV strains in Egypt and evaluate it against the commercially available Rotarix^® vaccine. Trial-IRVV was developed with 5% sucrose, 2% polysorbate-80, and adsorbed on Alum to potentiate the vaccine immune response. Then, it was injected subcutaneously into mice groups at 0-, 21-, and 35-time intervals. In parallel, Rotarix was administered twice on 0 and 28^th day. The success of the pentavalent-IRVV/monovalent-Rotarix vaccine immunity rested on achieving immunoglobulin G (IgG) exceeding 1:6,400 that implies less susceptibility to RV infection (RVI). IRVV stimulating IgG >1:6,400 could be an alternative vaccination approach to reach a reasonable protective immunization level against RVI. In addition, Alum adjuvant incorporation effectively provoked a triple elevation of the immunization pattern.

Rotavirus G and P types in children with acute diarrhea in Cairo, Egypt, 2011-2012

BACKGROUND

The WHO estimated the annual rotavirus-related mortality among children below 5 years old in Egypt in 2004 to be 30 deaths per 100 000, or out of an estimated 2616 deaths, 3.9% were because of rotavirus infection. The aim of this article was to study the epidemiology and circulating genotypes of rotaviruses in Cairo from 2011 to 2012.

MATERIALS AND METHODS

A total of 197 stool samples were collected from 130 inpatient children at the Cairo University Children Hospital and 67 outpatient children at the Al-Saff Children Clinic. The collected stool samples were then screened for rotavirus using enzyme immunoassay, followed by a screening for G-type and P-type using RT-PCR, and confirmation by sequence analysis.

RESULTS

Rotavirus was detected in 39.1% (77/197) of the children, with a higher rate in inpatients (43.9%, 57/130) than in outpatients (29.9%, 20/67). There was an increase of rotavirus infection in the winter season. The majority of rotavirus cases (85.7%) occurred during the first year of life. The predominant genotypes identified during this study were G3P[8] (37.7%) and G1P[8] (19.5%), but uncommon genotypes G1P[6] (3.9%), G9P[6] (1.3%), G8P[14] (1.3%), and G12P[6] (2.6%) were also detected.

CONCLUSION AND RECOMMENDATIONS

The change in genotype distribution, compared with previous studies, along with the high burden of rotavirus-associated diarrhea among Egyptian children below 2 years old, emphasizes the importance of continuing strain surveillance and the need of developing and introducing rotavirus vaccine in Egypt.

Rotavirus Diarrhea among Children in Taiz, Yemen: Prevalence-Risk Factors and Detection of Genotypes

Diarrheal diseases are a great public health problem; they are among the most causes leading to morbidity and mortality of infants and children particularly in developing countries and even in developed countries. Rotavirus is the most common cause of severe gastroenteritis in infants and young children in both developed and developing countries. The purpose of this study was to determine the incidence rate of Rotavirus infection, its genotypes, and risk factors among children with diarrhea in Taiz, Yemen. 795 fecal samples were collected from children (less than 5 years old), suffering from diarrhea and attending the Yemeni-Swedish Hospital (YSH) in Taiz , Yemen, from November 2006 to February 2008. Rotavirus was detected by enzyme linkage immunosorbent assay (ELISA) on stool specimens of children. Genotypes of Rotavirus were characterized by reverse transcriptase-polymerase chain reaction (RT-PCR) and polyacrylamide gel electrophoresis (PAGE). The results showed that 358 (45.2%) were Rotavirus-positive and the most prevalent genotypes were G2P[4] (55%), followed by G1P[8] (15%). In addition, Rotavirus was found through the whole year; however, higher frequency during the summer season (53.4%) and lower frequency during the winter season (37.1%).

Rotavirus genotypes associated with acute diarrhea in Egyptian infants

BACKGROUND

Before the introduction of rotavirus vaccine in Egypt, information on the burden of disease and the circulating rotavirus genotypes is critical to monitor vaccine effectiveness.

METHODS

A cohort of 348 Egyptian children was followed from birth to 2 years of age with twice-weekly home visits to detect diarrheal illness. VP7 and VP4 genes were genotyped by reverse-transcription polymerase chain reaction and DNA sequencing.

RESULTS

Forty percentage of children had rotavirus-associated diarrhea at least once by their second birthday. One hundred and twelve children experienced a single rotavirus diarrheal episodes (RDE) at a median age of 9 months; while 27 infants had their second RDE at a median age of 15 months and 1 infant had 3 RDE at the age of 2, 16 and 22 months. Of the 169 RDE, 82% could be assigned a G-type, while 58% had been identified a P-type. The most prevalent genotype was G2 (32%), followed by G1 (24%) and G9 (19%). G2P[4] rotavirus episodes were significantly associated with fever (P = 0.03) and vomiting (P = 0.06) when compared with other genotypes. G2 strains were the predominant genotype causing 50% of the second RDE while G9 represented 25% of the second RDE.

CONCLUSIONS

Genotypes identified are similar to those detected globally except for absence of G4. Our finding that 75% of the second RDE were due to G2 and G9 indicates a possible reduction in natural protection afforded by these types compared with G1, where 90% of G1 cases did not experience a second xposure, indicating greater protection against recurrent symptomatic infection.

Epidemiology of rotavirus diarrhea and diversity of rotavirus strains among children less than 5 years of age with acute gastroenteritis in Mauritius: June 2008 to December 2010

BACKGROUND

Rotavirus is an important etiologic agent of diarrhea worldwide and ongoing surveillance is essential to monitor strain diversity. To describe the epidemiology of rotavirus disease and circulating rotavirus strains in Mauritius, surveillance for rotavirus diarrhea was conducted at 2 regional hospitals from June 2008 through December 2010.

METHODS

A total of 787 fecal samples from children <5 years of age admitted to the pediatric ward with acute gastroenteritis was collected within 48 hours of hospitalization and analyzed for group A rotavirus. A subset of rotavirus-positive samples was subjected to polyacrylamide gel electrophoresis and VP4 and VP7 genotyping.

RESULTS

Rotavirus was detected in 327 (41.6%) stools. Highest prevalence of rotavirus infection occurred in children <2 years of age, predominately between 12 and 23 months. Three seasonal peaks were observed during the study period: July to October 2008, October to December 2009 and July to October 2010. Polyacrylamide gel electrophoresis analysis of 116 positive samples yielded only long electropherotypes. The predominant circulating strain was G3P[8] (89%) from June through December 2008, G4P[8] (76%) from January through December 2009 and G1P[8] (90%) from January through December 2010.

CONCLUSIONS

The diversity of rotavirus strains detected in this study highlights the need for continuous surveillance and data generated can be used to advocate for rotavirus vaccine introduction.

Detection of a neonatal human rotavirus strain with VP4 and NSP4 genes of porcine origin

A human rotavirus strain (NB-150) was detected in stool samples from a neonate hospitalized for mild/moderate community-acquired diarrhoea. This baby lived in the outskirts of Belém, Brazil, under poor sanitation conditions. The NB-150 strain displayed a typical long electrophoretic pattern with 11 gene segments. It had two VP7 alleles, G1 and G4, and belonged to VP6 subgroup II. A close relatedness with human rotaviruses was shown for VP7 alleles: G1 (96.9–100 % similarity at the amino acid level) and G4 (97.1–100 % similarity at the amino acid level). As for VP6, 95.1–97.5 % similarity at the amino acid level was noted. VP8* and NSP4 genes showed a close relatedness with those of porcine rotavirus strains, as follows: VP8* (95.0 % similarity at the amino acid level) and NSP4 (93.7–96.0 % similarity at the amino acid level). This is believed to be the first report in Brazil of a rotavirus infection involving a strain with G1 and G4 alleles, with VP8* and NSP4 genes of porcine origin. These findings strongly suggest the occurrence of interspecies transmission.

Analysis of human rotavirus G1P[8] strains by RFLP reveals higher genetic drift in the VP7 than the VP4 gene during a 4-year period in Mexico

Several studies have demonstrated that rotaviruses of the G1P[8] genotype are among the most important worldwide. Sequence analysis of G1P[8] strains has revealed high genetic variability of VP4 and VP7 genes. The aim of this study was to investigate by restriction fragment length polymorphism (RFLP) analysis the genetic variability of the VP7 and VP4 genes within rotaviruses of the G1P[8] genotype. A total of 60 rotavirus-positive fecal samples genotyped as G1P[8], were collected from children with acute diarrhea under 5 years of age, between October 1995 and October 1998. The VP7 and VP4 genes were amplified by RT/PCR, using the Beg9/End9 primer pair and the Con3 and Con2 primers, respectively. VP7 amplicons were digested with three restriction enzymes Hae III, Taq I and Rsa I in separate reactions and VP4 amplicons were digested similarly with endonucleases Hinf I, Sau96 I and Rsa I. Analysis of the digested VP7 and VP4 amplicons showed a higher genetic drift for the VP7 gene (18 RFLPs) compared to the VP4 gene (9 RFLPs). The combination of profiles for both VP7 and VP4 amplicons, showed 27 different patterns, none of them similar to the Wa-1 strain. Furthermore, RFLP analysis of these G1P[8] strains, clearly differentiated the viruses into two main clusters, both of them sharing the same restriction pattern for the VP4 gene, and a different one for the VP7 gene.

Global distribution of rotavirus serotypes/genotypes and its implication for the development and implementation of an effective rotavirus vaccine

A safe and effective rotavirus vaccine is urgently needed, particularly in developing countries. Critical to vaccine development and implementation is a knowledge base concerning the epidemiology of rotavirus G and P serotypes/genotypes throughout the world. The temporal and geographical distribution of human rotavirus G and P types was reviewed by analysing a total of 45571 strains collected globally from 124 studies reported from 52 countries on five continents published between 1989 and 2004. Four common G types (G1, G2, G3 and G4) in conjunction with P[8] or P[4] represented over 88% of the strains analysed worldwide. In addition, serotype G9 viruses associated with P[8] or P[6] were shown to have emerged as the fourth globally important G type with the relative frequency of 4.1%. When the global G and/or P type distributions were divided into five continents/subcontinents, several characteristic features emerged. For example, the P[8]G1 represented over 70% of rotavirus infections in North America, Europe and Australia, but only about 30% of the infections in South America and Asia, and 23% in Africa. In addition, in Africa (i) the relative frequency of G8 was as high as that of the globally common G3 or G4, (ii) P[6] represented almost one-third of all P types identified and (iii) 27% of the infections were associated with rotavirus strains bearing unusual combinations such as P[6]G8 or P[4]G8. Furthermore, in South America, uncommon G5 virus appeared to increase its epidemiological importance among children with diarrhea. Such findings have (i) confirmed the importance of continued active rotavirus strain surveillance in a variety of geographical settings and (ii) provided important considerations for the development and implementation of an effective rotavirus vaccine (e.g. a geographical P-G type adjustment in the formulation of next generation multivalent vaccines).

Group A rotavirus in sewage samples from Barcelona and Cairo: emergence of unusual genotypes

The presence of rotavirus strains in sewage samples from Cairo, Egypt (November 1998 to October 1999), and Barcelona, Spain (November 1998 to December 2002), was investigated by using a generic molecular detection method based on amplification of a VP6 gene fragment. Overall, 85.7 and 66.9% of the sewage samples from Cairo and Barcelona, respectively, were positive. Positive samples were characterized further, and VP7 and VP4 genotypes were determined. Although 30% of the positive samples from Cairo were G untypeable, the distribution of G types in the positive samples was 69.6% G1, 13% G3, 8.7% G4, and 8.7% G9. The percentage of untypeable samples was much higher for the Barcelona samples (56.5%), and the distribution in the positive samples was 56.4% G1, 31.5% G3, 6% G9, 4% G2, and 2% G5. When the P types were examined, 26.7% of the positive samples from Cairo were untypeable, and the distribution of types in the positive samples was 53.3% P[8], 30% P[6], and 16.6% P[4]. In Barcelona, 27.2% of the samples were P untypeable, and the frequencies of the types detected were 49.7% P[8], 37.2% P[4], 8.8% P[6], and 4.2% P[9]. The distribution for strains from Cairo was 38.5% P[8]G1, 27% P[6]G1, 11.5% P[4]G1, 11.5% P[8]G3, 7.7% P[6]G4, and 3.8% P[8]G9. Strikingly, equivalent frequencies of common and uncommon strains were observed for Barcelona samples, and the distribution was 38.8% P[8]G1, 30.6% P[4]G1, 11.6% P[8]G3, 6.6% P[4]G3, 5.8% P[6]G1, 1.6% P[6]G3, 1.6% P[9]G1, 0.8% P[4]G2, 0.8% P[6]G9, 0.8% P[8]G9, and 0.8% P[8]G5. Additionally, two P[-]G5 strains were isolated in Barcelona, and the porcine or human origin of these strains was unclear. Rotavirus variability exhibited not only a geographic pattern but also a temporal pattern.

Distribution of rotavirus VP7 serotypes and VP4 genotypes circulating in Sousse, Tunisia, from 1995 to 1999: emergence of natural human reassortants

Rotavirus strains circulating in Sousse, Tunisia, between 1995 and 1999 were characterized antigenically by monoclonal antibodies to the VP6 subgroup and the VP7 serotype. The VP4 genotype was determined by reverse transcription-PCR, as were the strains with untyped VP7. Only 17% of 375 children were shedding rotavirus as determined by latex agglutination assay. Most rotavirus strains were G1P[8] (50%), followed by G4P[8] and G4P[6]. Reassortant G1P[4] strains emerged in Sousse during the 1998-1999 season.

The current status of the rotavirus vaccine

The US just licensed of an oral tetravalent rhesus reassortant vaccine for routine immunization of infants against rotavirus. The virus was first identified 25 years ago and is now recognized to be the most common single cause of severe diarrhea throughout the world. Most children suffer at least one infection and reinfection is common. Studies of natural immunity show that breastfeeding may merely delay onset of primary infection and that maternal immunity has little effect-especially in developing countries where onset in early infancy is common. Immunity, furthermore, appears to be serotype-specific. Early attempts to develop a vaccine focused on animal forms of rotavirus. More recent efforts have created human-animal reassortants that have been far more successful.