Predominance of norovirus and sapovirus in Nicaragua after implementation of universal rotavirus vaccination.
BACKGROUND
Despite significant reduction of rotavirus (RV) infections following implementation of RotaTeq vaccination in Nicaragua, a large burden of patients with diarrhea persists.


METHODS
We conducted a community- and hospital-based study of the burden of RV, norovirus (NV) and sapovirus (SV) infections as cause of sporadic acute gastroenteritis (GE) among 330 children ≤ 5 years of age between September 2009 and October 2010 in two major cities of Nicaragua with a RotaTeq coverage rate of 95%.


RESULTS
We found that NV, SV and RV infections altogether accounted for 45% of cases of GE. Notably, NV was found in 24% (79/330) of the children, followed by SV (17%, 57/330) and RV (8%, 25/330). The detection rate in the hospital setting was 27%, 15% and 14% for NV, SV and RV respectively, whereas in the community setting the detection rate of RV was < 1%. Among each of the investigated viruses one particular genogroup or genotype was dominant; GII.4 (82%) for NV, GI (46%) for SV and G1P[8] (64%) in RV. These variants were also found in higher proportions in the hospital setting compared to the community setting. The GII.4.2006 Minerva strain circulating globally since 2006 was the most common among genotyped NV in this study, with the GII.4-2010 New Orleans emerging in 2010.


CONCLUSIONS
This study shows that NV has become the leading viral cause of gastroenteritis at hospital and community settings in Nicaragua after implementation of RV vaccination.
Department of Microbiology, University of León (UNAN-León), León, Nicaragua.
Filemón
F
Bucardo
Department of Microbiology, University of León (UNAN-León), León, Nicaragua.
Yaoska
Y
Reyes
Division of Molecular Virology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
Lennart
L
Svensson
Division of Molecular Virology, Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
Johan
J
Nordgren
D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000517:prevention & control; D002648:Child; D002675:Child, Preschool; D003151:Community Health Centers; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D014644:Genetic Variation; D005838:Genotype; D006761:Hospitals; D006801:Humans; D017589:Immunization Programs; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009527:Nicaragua / Q000453:epidemiology; D029322:Norovirus / Q000302:isolation & purification*; D060888:Real-Time Polymerase Chain Reaction; D012401:Rotavirus / Q000302:isolation & purification*; D012400:Rotavirus Infections / Q000453:epidemiology* / Q000517:prevention & control; D022243:Rotavirus Vaccines / Q000627:therapeutic use*; D029341:Sapovirus / Q000302:isolation & purification*; D014613:Vaccines, Attenuated / Q000627:therapeutic use
C492535:RotaTeq; D022243:Rotavirus Vaccines; D014613:Vaccines, Attenuated