Prevalence and genetic diversity of human caliciviruses (HuCVs) in Mexican children

Abstract

Human caliciviruses (HuCVs) contain two genera: "Norwalk-like viruses" (NLVs) and "Sapporo-like viruses" (SLVs). The importance of the two genera as a cause of acute gastroenteritis of infants and children remains unknown. Beginning in 1989, a birth cohort of children in Mexico was enrolled and monitored for acute gastroenteritis. A subset of 115 diarrhea stool specimens from 76 children and 66 non-diarrhea stool specimens from 64 children was examined for HuCVs by RT-PCR by using a primer pair (p289/290) that detects both NLVs and SLVs. Twenty-two (19%) of the 115 diarrhea stool specimens and 5 (7%) of 66 non-diarrhea stool specimens produced RT-PCR products of expected size (319 bp for NLVs and 331 bp for SLVs). Twenty of the twenty-seven strains were cloned and sequenced. Pairwise sequence analysis showed that 9 (60%) and 6 (40%) of the 15 strains from the diarrhea stools were NLVs and SLVs, respectively. The same proportions of NLVs (60%) and SLVs (40%) were observed in the non-diarrhea stools. Strains in the NLV genus could be further divided into four clusters: Lordsdale, MxV, and HV and one potentially new cluster. Strains in the SLV genus could be divided into three clusters: Sapporo/82, Lon/92, and a potentially new cluster. Strains from the Lordsdale cluster were the most common among these children. The findings of both genera and multiple clusters of HuCVs co-circulating and the identification of new strains of HuCVs in the population justify the need for future studies of HuCVs in infants and children.

Molecular and epidemiological trend of norovirus associated gastroenteritis in Dhaka City, Bangladesh

“…Several genotypes co-circulate, but the majority of infections are caused by a few genotypes (Koopmans et al, 2003). Predominance of GII strains over GI have been widely observed with sporadic cases of acute diarrhea and during outbreaks (Bon et al, 1999;Buesa et al, 2002;Farkas et al, 2000;Kirkwood and Bishop, 2001;Pang et al, 1999;Roman et al, 2002). This study showed that all Bangladeshi NoV sequences belonged only to genogroup II, which clustered into one genotype (GII/4).…”

Gastrointestinal pathogens detected by multiplex nucleic acid amplification testing in stools of pediatric patients and patients returning from the tropics

“…Incidence rates in children range from 7 to 20 % [13,19,21,23]. Detection rates of norovirus by multiplexNAT were considerably higher ([50 %) than by DAD, in line with the well-known lower sensitivity of DAD assays.…”

Norovirus Contamination of Bell Pepper from Handling During Harvesting and Packing

“…In Mexico, strains most frequently reported are Hawaii, Bristol, Lordsdale, and Mexico (Lewis et al 1992;Farkas et al 2000). The Lordsdale strain belongs to genotype 4 and it is the most prevalent around the world (Huang et al 2003;Tan et al 2006).…”