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Rotavirus A (RVA) causes acute diarrhoea in children and less frequently in adults. However, the knowledge about the genotype distribution of RVA strains circulating in adults is limited particularly in developing countries. This study aimed to characterise the RVA strains detected from adult patients with diarrhoea in Nepal. A total of 47 RVA positive stool samples from adult patients with diarrhoea in Kathmandu, Nepal during 2007-2008 were examined for the G and P genotypes by sequencing. Nearly half (49%) of the samples were genotyped as G9P[8] (n = 23), G1P[8], G2P[4] (n = 5 each), G12P[8] (n = 4), G12P[6] (n = 3), G1P[6] (n = 2), G3P[8] and G9P[6] (n = 1 each). Interestingly, two G11P[25] and one G9P[19] strains detected were further subjected to Illumina MiSeq next generation sequencing to determine their whole genome sequences. The genotype constellations of RVA/Human-wt/NPL/TK2615/2008/G11P[25] and RVA/Human-wt/NPL/TK2620/2008/G11P[25] were I12-R1-C1-M1-A1-N1-T1-E1-H1, whereas that of RVA/Human-wt/NPL/TK1797/2007/G9P[19] was I5-R1-C1-M1-A8-N1-T1-E1-H1. The 11 genes of TK2615 and TK2620 were virtually identical, and they were either porcine-like or unique except the VP2 and NSP1 genes which were of human RVA origin. The two G11P[25] strains were also very similar to KTM368, another G11P[25] isolated from a child in Nepal in 2004. On the other hand, no gene of TK1797 was likely to be of human RVA origin. The observation that porcine-like RVAs were detected from adult patients justifies further studies to explore the role of adults in the interspecies transmission of animal RVA to humans., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Two rotavirus vaccines, RotaTeq (Merck) and Rotarix (GlaxoSmithKline) have been developed to neutralize the most common rotavirus serotypes, and are now available in the global market. These vaccines are primarily aimed at reducing rotavirus gastroenteritis in children in the least developed countries, where rotavirus mortality rate is believed to be greatest. Thus, the World Health Organization (WHO) has recommended rotavirus vaccination be included in all national immunization programs, while the least developed countries have so far not come up with clear vision and long term strategy on vaccine implementation, and several questions, in addition to this, remain unanswered.

Rotavirus diarrhea is an important cause of child mortality in developing countries, but studies on this diarrhea are scarce in Sri Lanka. A prospective study conducted in Sri Lanka on rotavirus infection among children in a hospital setting (n = 611) versus children residing in tsunami camps (n = 52) showed that prevalence of rotavirus infection was comparable, 21.9 and 20%, respectively. The hospital and camps were located in different districts. Analysis of the genotypes of 122 rotaviruses from the hospital and 12 from the camps indicated that G9P[8] was associated with 35 and 33%; G12P[8/nt] with 14.7 and 33%; G3P[8/4/nt] with 17 and 8% and G1P[8/4] with 6.5 and 16.7%. Rotaviruses with G2P[8/4/6] and G4P[8/4] were hospital-associated only, and some rotaviruses (9 and 8% from the hospital and the camps, respectively) were G- and P-nontypable. We conclude from the present study that multiple emerging genotypes were prevalent in Sri Lanka, and children in camps were at risk of developing diarrhea due to rotaviruses.

Of 731 stool specimens collected from children with diarrhea in Kathmandu, Nepal, from August 2004 through July 2005, 170 (23.3%) tested positive for rotavirus. Reverse transcription--PCR, including a revised G12-specific primer set, identified 56 (32.9%) as G2P[4] and 39 (23.0%) as G12 with P[6], P[8], or P[4]. [ABSTRACT FROM AUTHOR]