Origin, distribution, and potential risk factors associated with influenza A virus in swine in two production systems in Guatemala.

BACKGROUND: Guatemala is the country with the largest swine production in Central America; however, evidence of influenza A virus (IAV) in pigs has not been clearly delineated. OBJECTIVES: In this study, we analyzed the presence and spatial distribution of IAV in commercial and backyard swine populations. METHODS: Samples from two nationwide surveys conducted in 2010 and 2011 were tested using virological (rRT-PCR and virus isolation) and serological (ELISA and hemagglutination inhibition) assays to detect IAV. RESULTS: Influenza A virus was detected in 15.7% of the sampled pigs (30.6% of herds) in 2010 and in 11.7% (24.2% of herds) in 2011. The percentage of seropositive pigs was 10.6% (16.1% of herds) and 1.4% (3.1% of herds) for each year, respectively. Three pandemic H1N1 and one seasonal human-like H3N2 viruses were isolated. Antibodies against viruses from different genetic clusters were detected. No reassortant strains with swine viruses were detected. The H3N2 virus was closely related to human viruses that circulated in Central America in 2010, distinct to the most recent human seasonal vaccine lineages. Spatial clusters of rRT-PCR positive herds were detected each year by scan statistics. CONCLUSIONS: Our results demonstrate circulation of IAV throughout Guatemala and identify commercial farms, animal health status, and age as potential risk factors associated with IAV infection and exposure. Detection of human-origin viruses in pigs suggests a role for humans in the molecular epidemiology of IAV in swine in Guatemala and evidences gaps in local animal and human surveillance.

West Nile virus ecology in a tropical ecosystem in Guatemala.

West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States.

Influenza a viruses from wild birds in Guatemala belong to the North American lineage.

The role wild bird species play in the transmission and ecology of avian influenza virus (AIV) is well established; however, there are significant gaps in our understanding of the worldwide distribution of these viruses, specifically about the prevalence and/or significance of AIV in Central and South America. As part of an assessment of the ecology of AIV in Guatemala, we conducted active surveillance in wild birds on the Pacific and Atlantic coasts. Cloacal and tracheal swab samples taken from resident and migratory wild birds were collected from February 2007 to January 2010.1913 samples were collected and virus was detected by real time RT-PCR (rRT-PCR) in 28 swab samples from ducks (Anas discors). Virus isolation was attempted for these positive samples, and 15 isolates were obtained from the migratory duck species Blue-winged teal. The subtypes identified included H7N9, H11N2, H3N8, H5N3, H8N4, and H5N4. Phylogenetic analysis of the viral sequences revealed that AIV isolates are highly similar to viruses from the North American lineage suggesting that bird migration dictates the ecology of these viruses in the Guatemalan bird population.

Norovirus outbreak of probable waterborne transmission with high attack rate in a Guatemalan resort.

BACKGROUND: In February 2009, a group of Guatemalan school children developed acute gastroenteritis (AGE) after participating in a school excursion. OBJECTIVES: We conducted a retrospective cohort investigation to characterize the outbreak and guide control measures. STUDY DESIGN: A case was defined as an illness with onset of diarrhea or vomiting during February 25-March 5, 2009. Participants were interviewed using a standardized questionnaire, and stool specimens were collected. We inspected the excursion site and tested water samples for total coliforms and Escherichia coli. RESULTS: We identified 119 excursion participants, of which 92 (77%) had been ill. Fifty-six (62%) patients sought care for their illness, and three (3%) were hospitalized. Eighteen (90%) of the 20 specimens from ill children tested positive for norovirus. Among these, 16 (89%) were of the genogroup I (GI.7) and two (11%) were genogroup II (GII.12 and GII.17). One (8%) of the 12 food handlers had norovirus (GI.7). Drinking water samples had 146 most probable numbers (MPN)/100ml of total coliforms and five MPN/100ml of E. coli. CONCLUSION: We describe the first laboratory-confirmed norovirus outbreak in Guatemala. The high illness attack rate, detection of multiple norovirus strains in sick persons, and presence of fecal contamination of drinking water indicate likely waterborne transmission.