Information about norovirus (NoV) infections in

, a total of 526 faecal samples from children aged 0-60 months (381 with and 145 without diarrhoea) from Leó n, Nicaragua, were studied. In order to detect five different diarrhoeagenic Escherichia coli pathotypes simultaneously [enterotoxigenic E. coli (ETEC), enteroaggregative E. coli (EAEC), enteropathogenic E. coli (EPEC), enterohaemorrhagic E. coli (EHEC) and enteroinvasive E. coli (EIEC)], a mixture of eight primer pairs was used in a single PCR. At least one diarrhoeagenic E. coli pathotype was detected in 205 samples (53.8 %) of the diarrhoea group and in 77 samples (53.1 %) in the non-diarrhoea group. ETEC was detected significantly more often in children with diarrhoea (20.5 %) than in children without diarrhoea (8.3 %) (P50.001). Atypical EPEC, EIEC and EAEC were detected with slightly lower frequencies in children with (16.0, 0.8 and 27.8 %, respectively) than in children without (20.7, 1.4 and 33.1 %, respectively) diarrhoea. EHEC was only detected in children with diarrhoea (2.1 %). In conclusion, ETEC continues to be an important agent associated with diarrhoea in children from Leó n, Nicaragua. Although not very frequent, the only findings that were 100 % associated with diarrhoea were ETEC estA (4.7 %) and EHEC (2.1 %). Nevertheless, EAEC and EPEC were also frequent pathotypes in the population under study. In children with severe diarrhoea, more than half had EAEC, ETEC or EPEC, and EAEC was the most prevalent pathotype.

Host genetic resistance to Norovirus (NoV) has been observed in challenge and outbreak studies in populations from Europe, Asia, and USA. In this study, we have investigated if histo-blood group antigens can predict susceptibility to diarrhea caused by NoV in Nicaragua, Central America, and if this can be reflected in antibody-prevalence and titer to NoV among individuals with different histo-blood group antigen phenotypes. Investigation of 28 individuals infected with NoV and 131 population controls revealed 6% of non-secretors in the population and nil non-secretors among patients infected with NoV, suggesting that non-secretors may be protected against NoV disease in Nicaragua. Surprisingly, 25% of the population was Lewis negative (Le(a-b-)). NoV infections with genogroup I (GI) and GII occurred irrespective of Lewis genotype, but none of the Lewis a positive (Le(a + b-)) were infected. The globally dominating GII.4 virus infected individuals of all blood groups except AB (n = 5), while the GI viruses (n = 4) infected only blood type O individuals. Furthermore, O blood types were susceptible to infections with GI.4, GII.4, GII.7, GII.17, and GII.18-Nica viruses, suggesting that secretors with blood type O are susceptible (OR = 1.52) and non-secretors resistant. The overall antibody-prevalence to NoV GII.3 VLP was 62% with the highest prevalence among blood type B carriers (70%) followed by A (68%) and O (62%). All four investigated individuals carrying blood type AB were antibody-negative. Among secretors, 63% were antibody-positive compared to 33% among non-secretors (P = 0.151). This study extends previous knowledge about the histo-blood group antigens role in NoV disease in a population with different genetic background than North American and European.

Background Nicaragua was the first developing nation to implement routine immunization with the pentavalent rotavirus vaccine (RV5). In this RV5-immunized population, understanding infectious etiologies of childhood diarrhea is necessary to direct diarrhea treatment and prevention efforts. Methods We followed a population-based sample of children less than 5 years in León, Nicaragua for diarrhea episodes through household visits. Information was obtained on RV5 history and sociodemographics. Stool samples collected during diarrhea episodes and among healthy children underwent laboratory analysis for viral, bacterial, and parasitic enteropathogens. Detection frequency and incidence of each enteropathogen was calculated. Results The 826 children in the cohort experienced 677 diarrhea episodes during 607.5 child-years of exposure time (1.1 episodes per child-year). At least one enteropathogen was detected among 61.1% of the 337 diarrheal stools collected. The most common enteropathogens among diarrheal stools were: norovirus (20.4%), sapovirus (16.6%), enteropathogenic Escherichia coli (EPEC, 11.3%), Entamoeba histolytica/dispar (8.3%), Giardia lamblia (8.0%), and enterotoxigenic E.coli (ETEC, 7.7%), with rotavirus detected among 5.3% of diarrheal stools. EPEC and ETEC were frequently detected among stools from healthy children. Among children with diarrhea, norovirus was more commonly detected among younger children (< 2 years) and G. lamblia was more commonly detected among older children (2-4 years). The mean age of rotavirus detection was 34.6 months. Conclusions In this Central American community following RV5 introduction, rotavirus was not commonly detected among children with diarrhea. Prevention and appropriate management of norovirus and sapovirus should be considered to further reduce the burden of diarrheal disease.

Antibiotic-resistant bacteria have emerged due to the selective pressure of antimicrobial use in humans and animals. Water plays an important role in dissemination of these organisms among humans, animals and the environment. We studied the antibiotic resistance patterns among 493 Escherichia coli isolates from different aquatic environmental sources collected from October 2008 to May 2009 in León, Nicaragua. High levels of antibiotic resistance were found in E. coli isolates in hospital sewage water and in eight of 87 well-water samples. Among the resistant isolates from the hospital sewage, ampicillin, chloramphenicol, ciprofloxacin, nalidixic acid, trimethoprim-sulphamethoxazole was the most common multi-resistance profile. Among the resistant isolates from the wells, 19% were resistant to ampicillin, ceftazidime, ceftriaxone, cefotaxime, chloramphenicol, ciprofloxacin, gentamicin, nalidixic acid and trimethoprim-sulphamethoxazole. E. coli producing ESBL and harbouring bla(CTX-M) genes were detected in one of the hospital sewage samples and in 26% of the resistant isolates from the well-water samples. The bla(CTX-M-9) group was more prevalent in E. coli isolates from the hospital sewage samples and the bla(CTX-M-1) group was more prevalent in the well-water samples.

Rotavirus is the single most important etiologic agent of acute diarrhea mainly affecting children under the age of 5 (32). Each year human rotavirus (HRV) causes approximately 2 million hospitalizations and approximately 440,000 deaths, with the majority of the mortality in children from less industrialized countries (32).It is estimated that all children will be infected at least once by the age of 5 years (5), which leads to protective immunity later in life. In adults rotavirus infections are usually asymptomatic, but there are reports of disease in elderly and immunocompromised patients (1,4,26,28,33).Reports from different countries suggest an epidemiological shift of HRV strains over the years (20,30). It seems that one specific variant or lineage within the serotypes might be responsible for outbreaks in well-defined geographic regions; for instance, the lineage Ic of the strain G4P[8] increased in prevalence in some cities of Argentina in 1998 and 1 year later in Paraguay (7, 9). The lineage Ic of the G4P[8] strain was also found to circulate in Italy in 1999 and 2000 (3), and during the rotavirus season in 1997 the emergence of a G4P[6] strain with a different RNA profile was observed in South Africa (34). Furthermore, in Nicaragua the uncommon strain G4P[6] was observed to circulate at very low frequency in 2001 and 2002 (12). The emergence of these novel strains and new lineages is due to different evolutionary mechanisms including gene rearrangements, accumulation of point mutations, and reassortment of genome segments (18).During February and March 2005, one of the largest recorded outbreaks of severe acute gastroenteritis occurred in Nicaragua, affecting Ն64,000 individuals and causing at least 56 deaths, with children Ͻ5 years of age being most affected. We have carried out a molecular epidemiology study to investigate properties of the rotavirus strains associated with this unique and large epidemic outbreak. Our main observation was that the outbreak was associated with a mutated G4P [8] virus not previously detected in Nicaragua and most likely introduced from South America. The knowledge from this study may have implications for rotavirus prevention including vaccine introduction in Nicaragua. MATERIALS AND METHODSGeographic distribution of collected stool samples. During February and March 2005, a total of 108 stool samples were collected through a laboratorybased survey of acute diarrhea cases, defined as three or more liquid stools over a 24-h period (12-14). The surveillance was performed in the main hospital of every city included in this study; therefore, most of the samples (55/108; 76.4%) came from moderate to severe cases. A portion of the samples (17/72; 23.6%) was collected in the laboratory of the Department of Microbiology of the National Autonomous University of Nicaragua-Leon serving mainly outpatients.The stool specimens were stored at 4°C until transported to the Department of Microbiology of the National Autonomous University of Nicaragua-Leon. A suspension of 10% (vol/vol)...

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Rotavirus infections are acquired very early in infants in León, Nicaragua, and reinfections are common. Most infections are asymptomatic. Breast milk appears to confer partial protection against rotavirus infection, probably mediated by specific IgA antibodies. To be effective rotavirus vaccination would probably have to be given at a very early age to infants in developing countries.