Incidence and etiology of infectious diarrhea from a facility-based surveillance system in Guatemala, 2008-2012.

BACKGROUND: Diarrhea is a major cause of morbidity and mortality, yet incidence and etiology data are limited. We conducted laboratory-based diarrhea surveillance in Guatemala. METHODS: A diarrhea case was defined as ≥3 loose stools in a 24-h period in a person presenting to the surveillance facilities. Epidemiologic data and stool specimens were collected. Specimens were tested for bacterial, parasitic, and viral pathogens. Yearly incidence was adjusted for healthcare seeking behaviors determined from a household survey conducted in the surveillance catchment area. RESULTS: From November 2008 to December 2012, the surveillance system captured 5331 diarrhea cases; among these 1381 (26%) had specimens tested for all enteric pathogens of interest. The adjusted incidence averaged 659 diarrhea cases per 10,000 persons per year, and was highest among children aged < 5 years, averaging 1584 cases per 10,000 children per year. Among 1381 (26%) specimens tested for all the pathogens of interest, 235 (17%) had a viral etiology, 275 (20%) had a bacterial, 50 (4%) had parasites, and 86 (6%) had co-infections. Among 827 (60%) specimens from children aged < 5 years, a virus was identified in 196 (23%) patients; 165 (20%) had norovirus and 99 (12%) rotavirus, including co-infections. Among 554 patients aged ≥5 years, 103 (19%) had a bacterial etiology, including diarrheagenic Escherichia coli in 94 (17%) cases, Shigella spp. in 31 (6%), Campylobacter spp. in 5 (1%), and Salmonella spp. in 4 (1%) cases. Detection of Giardia and Cryptosporidium was infrequent (73 cases; 5%). CONCLUSIONS: There was a substantial burden of viral and bacterial diarrheal diseases in Guatemala, highlighting the importance of strengthening laboratory capacity for rapid detection and control and for evaluation of public health interventions.

Incidence and Clinical Profile of Norovirus Disease in Guatemala, 2008-2013.

Background: Acute gastroenteritis (AGE) is a leading infectious cause of morbidity worldwide, particularly among children in developing countries. With the decline of rotavirus disease rates following introduction of rotavirus vaccines, the relative importance of norovirus will likely increase. Our objectives in this study were to determine the incidence and clinical profile of norovirus disease in Guatemala. Methods: We analyzed data from a population-based surveillance study conducted in Guatemala from 2008 through 2013. Demographic information, clinical data, and stool samples were collected from patients who presented with AGE (≥3 liquid stools within 24 hours that initiated 7 days before presentation). Estimated incidence of hospitalized, outpatient, and total community norovirus disease was calculated using surveillance data and household surveys of healthcare use. Results: We included 999 AGE hospitalizations and 3189 AGE outpatient visits at facilities, of which 164 (16%) and 370 (12%), respectively, were positive for norovirus. Severity of norovirus was milder than of rotavirus. Community incidence of norovirus ranged from 2068 to 4954 per 100000 person-years (py) in children aged<5 years. Children aged <5 years also had higher incidence of norovirus-associated hospitalization (51-105 per 100000 py) compared with patients aged ≥5 years (0-1.6 per 100000 py and 49-80 per 100000 py, respectively). Conclusions: This study highlights the burden of norovirus disease in Guatemala, especially among young children. These data can help prioritize development of control strategies, including the potential use of vaccines, and provide a baseline to evaluate the impact of such interventions.

Respiratory syncytial virus infection in Guatemala, 2007-2012.

BACKGROUND: Respiratory syncytial virus (RSV) is a major cause of acute respiratory illness (ARI). Little is known about RSV disease among older children and adults in Central America. METHODS: Prospective surveillance for ARI among hospital patients and clinic patients was conducted in Guatemala during 2007-2012. Nasopharyngeal and oropharyngeal swab specimens were tested for RSV, using real-time reverse-transcription polymerase chain reaction. RESULTS: Of 6287 hospitalizations and 2565 clinic visits for ARI, 24% and 12%, respectively, yielded RSV-positive test results. The incidence of RSV-positive hospitalization for ARI was 5.8 cases/10 000 persons per year and was highest among infants aged <6 months (208 cases/10 000 persons per year); among adults, the greatest incidence was observed among those aged ≥ 65 years (2.9 cases/10 000 persons per year). The incidence of RSV-positive clinic visitation for ARI was 32 cases/10 000 persons per year and was highest among infants aged 6-23 months (186 cases/10 000 persons per year). Among RSV-positive hospital patients with ARI, underlying cardiovascular disease was associated with death, moribund discharge, intensive care unit admission, or mechanical ventilation (odds ratio, 4.1; 95% confidence interval, 1.9-8.8). The case-fatality proportion among RSV-positive hospital patients with ARI was higher for those aged ≥ 5 years than for those aged <5 years (13% vs 3%; P < .001). CONCLUSIONS: The incidences of RSV-associated hospitalization and clinic visitation for ARI were highest among young children, but a substantial burden of ARI due to RSV was observed among older children and adults.

Prevalence and genetic diversity of norovirus among patients with acute diarrhea in Guatemala.

Noroviruses (NoVs) are a leading cause of acute gastroenteritis outbreaks and sporadic cases of diarrhea in industrialized countries. To study the prevalence and genetic diversity of NoVs in Guatemala, stool specimens were collected from hospitalized and ambulatory patients presenting with diarrhea (≥3 loose or liquid stools in a 24-hr period) who were enrolled in a prospective surveillance system in the Departments of Santa Rosa (October 2007 to August 2010) and Quetzaltenango (August 2009 to August 2010), Guatemala. Specimens were tested for rotavirus, enteric bacteria, and parasites by routine methods and for genogroups I and II NoV by real-time reverse transcription-PCR. A total of 2,403 stool specimens were collected from hospitalized (n = 528) and ambulatory patients (n = 1,875). Overall, 341 (14%) samples tested positive for NoVs including 114 (22%) hospitalized and 227 (12%) ambulatory patients. NoVs disease peaked during the winter (November-January) months. Among the 341 NoVs-positive patients, 32 (9%) were also positive for rotavirus, 32 (9%) for bacteria, and 9 (3%) for protozoa. Nucleotide sequences were obtained from 84 samples collected from hospitalized children aged <5 years of age, which could be grouped into nine GII and three GI genotypes with GII.4 (74%) and GI.8 (10%) being the most common. This is the first study on the prevalence of NoVs among hospitalized and ambulatory patients with diarrhea in Guatemala. The findings highlight the need to implement laboratory diagnostics for NoVs to improve appropriate clinical management of diarrheal diseases and guide vaccine development.

Multilocus variable-number tandem-repeat analysis of Mycoplasma pneumoniae clinical isolates from 1962 to the present: a retrospective study.

In this study, we evaluated a recently developed multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) method for the molecular typing of Mycoplasma pneumoniae. The method is based on GeneScan analysis of five VNTR loci throughout the genome which define a specific genotype based on the number of tandem repeats within each locus. A retrospective analysis of 154 M. pneumoniae clinical isolates collected over the last 50 years and a limited (n = 4) number of M. pneumoniae-positive primary specimens acquired by the CDC was performed using MLVA. Eighteen distinct VNTR types were identified, including two previously unidentified VNTR types. Isolates from several M. pneumoniae community outbreaks within the United States were also analyzed to examine clonality of a specific MLVA type. Observed in vitro variability of the Mpn1 VNTR locus prompted further analysis, which showed multiple insertions or deletions of tandem repeats within this locus for a number of specimens and isolates. To our knowledge, this is the first report showing variation within the Mpn1 locus, thus affecting precise and reliable classification using the current MLVA typing system. The superior discriminatory capability of MLVA provides a powerful tool for greater resolution of M. pneumoniae strains and could be useful during outbreaks and epidemiological investigations.

Bartonella spp. in Bats, Guatemala.

To better understand the role of bats as reservoirs of Bartonella spp., we estimated Bartonella spp. prevalence and genetic diversity in bats in Guatemala during 2009. We found prevalence of 33% and identified 21 genetic variants of 13 phylogroups. Vampire bat-associated Bartonella spp. may cause undiagnosed illnesses in humans.

Comparative epidemiology of human metapneumovirus- and respiratory syncytial virus-associated hospitalizations in Guatemala.

BACKGROUND: Human metapneumovirus (HMPV) is an important cause of acute respiratory infections (ARI), but little is known about how it compares with respiratory syncytial virus (RSV) in Central America. OBJECTIVES: In this study, we describe hospitalized cases of HMPV- and RSV-ARI in Guatemala. METHODS: We conducted surveillance at three hospitals (November 2007-December 2012) and tested nasopharyngeal and oropharyngeal swab specimens for HMPV and RSV using real-time reverse transcription-polymerase chain reaction. We calculated incidence rates, and compared the epidemiology and outcomes of HMPV-positive versus RSV-positive and RSV-HMPV-negative cases. RESULTS: We enrolled and tested specimens from 6288 ARI cases; 596 (9%) were HMPV-positive and 1485 (24%) were RSV-positive. We observed a seasonal pattern of RSV but not HMPV. The proportion HMPV-positive was low (3%) and RSV-positive high (41%) for age <1 month, whereas these proportions were similar (~20%) by age 2 years. The annual incidence of hospitalized HMPV-ARI was 102/100 000 children aged <5 years [95% confidence interval (CI): 75-178], 2.6/100 000 persons aged 5-17 years (95%CI: 1.2-5.0), and 2.6/100 000 persons aged ≥ 18 years (95%CI: 1.5-4.9). Among children aged <5 years, HMPV-positive cases were less severe than HMPV-RSV-negative cases after adjustment for confounders [odds ratio (OR) for intensive care = 0.63, 95% CI 0.47-0.84]; OR for death = 0.46, 95% CI 0.23-0.92). CONCLUSIONS: Human metapneumovirus is a substantial contributor to ARI hospitalization in Guatemala, but HMPV hospitalizations are less frequent than RSV and, in young children, less severe than other etiologies. Preventive interventions should take into account the wide variation in incidence by age and unpredictable timing of incidence peaks.

Diagnostic performance of rectal swab versus bulk stool specimens for the detection of rotavirus and norovirus: implications for outbreak investigations.

BACKGROUND: In January of 2008, during the peak of the rotavirus season in Guatemala, a gastroenteritis outbreak with high mortality among infants was reported in Guatemala. Despite extensive efforts, the investigation was limited by the lack of bulk stool specimens collected, particularly from the more severely dehydrated or deceased children. OBJECTIVES: We evaluated the diagnostic performance of rectal swab specimens compared with bulk stool for the detection of rotavirus and norovirus. STUDY DESIGN: Patients with diarrhea (≥3 loose stools in 24 h) were enrolled through an ongoing surveillance system in Guatemala. From January through March 2009, we attempted to enroll 100 patients <5 years old captured by the diarrhea surveillance, and collected paired bulk stool and rectal swabs specimens from them. Specimens were tested for norovirus using real-time reverse transcription-polymerase chain reaction and for rotavirus via enzyme immunoassay. RESULTS: We enrolled 102 patients with paired specimens; 91% of 100 paired specimens tested for rotavirus yielded concordant results positive for rotavirus with a negativity rate of 83%. Among 100 paired specimens tested for norovirus, 86% were concordant norovirus detection and the negativity rate was 85%. The diagnostic performance for rotavirus and norovirus detection did not differ significantly between the two specimen types. CONCLUSIONS: Testing of properly collected fecal specimens using rectal swabs may be a viable alternative to bulk stool for detection of rotavirus and norovirus, particularly during outbreaks where collection of bulk stool may be difficult.

The epidemiology and clinical characteristics of young children hospitalized with respiratory syncytial virus infections in Guatemala (2007-2010).

BACKGROUND: There have been few population-based studies from Central America on respiratory syncytial virus (RSV) infections in young children. We report population-based incidence rates and describe epidemiological and clinical characteristics of children <5 years old hospitalized with RSV infections in Guatemala. METHODS: Prospective, active hospital-based surveillance for acute respiratory infections in children <5 years old was conducted at 3 hospitals in Guatemala from November 2007 through July 2010. RSV hospitalization rates were calculated for areas where the catchment population could be defined. Comparisons were made between children who were RSV-positive and RSV-negative. RESULTS: RSV was detected in 549 (25%) of enrolled children. Overall, annual rates of RSV hospitalizations ranged from 5.9 to 45.9 and 2.0 to 13.7 per 1000 children <1 year old and <5 years old, respectively, but varied by location and calendar year. Rates generally decreased with age--children <6 months had rates up to 30 times higher than older children, but children >12 months old still had rates up to 5.5 per 1000 per year and accounted for 42% of deaths. Children with RSV infections were more likely to have signs of respiratory distress (85% versus 63%, P < 0.001) compared with those without RSV infections, but case fatality ratios were similar (3-4%). CONCLUSIONS: The large burden and severity of RSV infections in young Guatemalan children is similar in magnitude and age distribution to RSV disease burdens found in other developing countries and suggests that this population would benefit from prevention strategies, including vaccines against RSV that are currently under development.

Surveillance for hospitalized acute respiratory infection in Guatemala.

Acute respiratory infections (ARI) are an important cause of illness and death worldwide, yet data on the etiology of ARI and the population-level burden in developing countries are limited. Surveillance for ARI was conducted at two hospitals in Guatemala. Patients admitted with at least one sign of acute infection and one sign or symptom of respiratory illness met the criteria for a case of hospitalized ARI. Nasopharyngeal/oropharyngeal swabs were collected and tested by polymerase chain reaction for adenovirus, parainfluenza virus types 1,2 and 3, respiratory syncytial virus, influenza A and B viruses, human metapneumovirus, Chlamydia pneumioniae, and Mycoplasma pneumoniae. Urine specimens were tested for Streptococcus pneumoniae antigen. Blood culture and chest radiograph were done at the discretion of the treating physician. Between November 2007 and December 2011, 3,964 case-patients were enrolled. While cases occurred among all age groups, 2,396 (60.4%) cases occurred in children <5 years old and 463 (11.7%) among adults ≥65 years old. Viruses were found in 52.6% of all case-patients and 71.8% of those aged <1 year old; the most frequently detected was respiratory syncytial virus, affecting 26.4% of case-patients. Urine antigen testing for Streptococcus pneumoniae performed for case-patients ≥15 years old was positive in 15.1% of those tested. Among 2,364 (59.6%) of case-patients with a radiograph, 907 (40.0%) had findings suggestive of bacterial pneumonia. Overall, 230 (5.9%) case-patients died during the hospitalization. Using population denominators, the observed hospitalized ARI incidence was 128 cases per 100,000, with the highest rates seen among children <1 year old (1,703 per 100,000), followed by adults ≥65 years old (292 per 100,000). These data, which demonstrate a substantial burden of hospitalized ARI in Guatemala due to a variety of pathogens, can help guide public health policies aimed at reducing the burden of illness and death due to respiratory infections.

Rickettsia felis in Ctenocephalides felis from Guatemala and Costa Rica.

Rickettsia felis is an emerging human pathogen associated primarily with the cat flea Ctenocephalides felis. In this study, we investigated the presence of Rickettsia felis in C. felis from Guatemala and Costa Rica. Ctenocephalides felis were collected directly from dogs and cats, and analyzed by polymerase chain reaction for Rickettsia-specific fragments of 17-kDa protein, OmpA, and citrate synthase genes. Rickettsia DNA was detected in 64% (55 of 86) and 58% (47 of 81) of flea pools in Guatemala and Costa Rica, respectively. Sequencing of gltA fragments identified R. felis genotype URRWXCal(2) in samples from both countries, and genotype Rf2125 in Costa Rica. This is the first report of R. felis in Guatemala and of genotype Rf2125 in Costa Rica. The extensive presence of this pathogen in countries of Central America stresses the need for increased awareness and diagnosis.

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.

A comparison of the epidemiology and clinical presentation of seasonal influenza A and 2009 pandemic influenza A (H1N1) in Guatemala.

BACKGROUND: A new influenza A (H1N1) virus was first found in April 2009 and proceeded to cause a global pandemic. We compare the epidemiology and clinical presentation of seasonal influenza A (H1N1 and H3N2) and 2009 pandemic influenza A (H1N1) (pH1N1) using a prospective surveillance system for acute respiratory disease in Guatemala. METHODOLOGY/FINDINGS: Patients admitted to two public hospitals in Guatemala in 2008-2009 who met a pneumonia case definition, and ambulatory patients with influenza-like illness (ILI) at 10 ambulatory clinics were invited to participate. Data were collected through patient interview, chart abstraction and standardized physical and radiological exams. Nasopharyngeal swabs were taken from all enrolled patients for laboratory diagnosis of influenza A virus infection with real-time reverse transcription polymerase chain reaction. We identified 1,744 eligible, hospitalized pneumonia patients, enrolled 1,666 (96%) and tested samples from 1,601 (96%); 138 (9%) had influenza A virus infection. Surveillance for ILI found 899 eligible patients, enrolled 801 (89%) and tested samples from 793 (99%); influenza A virus infection was identified in 246 (31%). The age distribution of hospitalized pneumonia patients was similar between seasonal H1N1 and pH1N1 (P = 0.21); the proportion of pneumonia patients <1 year old with seasonal H1N1 (39%) and pH1N1 (37%) were similar (P = 0.42). The clinical presentation of pH1N1 and seasonal influenza A was similar for both hospitalized pneumonia and ILI patients. Although signs of severity (admission to an intensive care unit, mechanical ventilation and death) were higher among cases of pH1N1 than seasonal H1N1, none of the differences was statistically significant. CONCLUSIONS/SIGNIFICANCE: Small sample sizes may limit the power of this study to find significant differences between seasonal influenza A and pH1N1. In Guatemala, influenza, whether seasonal or pH1N1, appears to cause severe disease mainly in infants; targeted vaccination of children should be considered.

Population-based surveillance for 2009 pandemic influenza A (H1N1) virus in Guatemala, 2009.

BACKGROUND: In April 2009, 2009 pandemic influenza A H1N1 (2009 H1N1) was first identified in Mexico but did not cause widespread transmission in neighboring Guatemala until several weeks later. METHODOLOGY AND PRINCIPLE FINDINGS: Using a population-based surveillance system for hospitalized pneumonia and influenza-like illness ongoing before the 2009 H1N1 pandemic began, we tracked the onset of 2009 H1N1 infection in Guatemala. We identified 239 individuals infected with influenza A (2009 H1N1) between May and December 2009, of whom 76 were hospitalized with pneumonia and 11 died (case fatality proportion: 4.6%, 95% confidence interval [CI] 2.3-8.1%). The median age of patients infected with 2009 H1N1 was 8.8 years, the median age of those hospitalized with pneumonia was 4.2 years, and five (45.5%) deaths occurred in children <5 years old. Crude rates of hospitalization between May and December 2009 were highest for children <5 years old. Twenty-one (27.6%) of the patients hospitalized with 2009 H1N1 were admitted to the intensive care unit and eight (10.5%) required mechanical ventilation. Underlying chronic conditions were noted in 14 (18.4%) of patients with pneumonia hospitalized with 2009 H1N1 infection. CONCLUSIONS AND SIGNIFICANCE: Chronic illnesses may be underdiagnosed in Guatemala, making it difficult to identify this risk group for vaccination. Children 6 months to 5 years old should be among priority groups for vaccination to prevent serious consequences because of 2009 H1N1 infection.

Rol del oxido nítrico en la síntesis de prostaglandina F2alpha y progesterona durante la luteolisis en la rata / Role of nitric oxide in the synthesis of prostaglandin F2alpha and progesterone during luteolysis in the rat

En el cuerpo lúteo (CL), la prostaglandina F2alpha (PGF2alpha) es un agente luteolítico. El óxido (NO) es una molécula mensajera capaz de regular diversos procesos patofisiológicos, algunos de ellos relacionados com el tracto rerpoductivo femenino. El objetivo del presente estudio fue investigar el rol del NO ovárico en la producción de PGF2alpha y progesterona (Pg) durante la regresión del CL en la rata. Se utilizó para ello el modelo de la rata pseudopreñada, obteniéndose un cuerpo lúteo funcional por 9 + 1 días. Fueron inyectados en bursa ovárica dos inhibidores competitivos de la óxido nítrico sintasa (Nos), NG-monometil-L-arginina (L-NMMA), 1 mg/kg); NW-nitro-L-arginina metil éster (L-NAME, 3 mg/kg) así como también un generador de NO como el nitroprusiato sódico (SNP, 0.05 mg/kg). Los resultados obtenidos indican que el NO, producido en el ovario durante la fase final del desarrollo del CL (días 8 y 9), actuaría aimentando la producción de PGF2alpha ovárica y disimuyendo la progesterona sérica desencadenando la regresión luteal. Se há propuesto un mecanismo de feedback positivo entre la PGF2alpha y el NO hacia la fase final del desarrollo del Cl, para asegurar la luteólisis. Esto fue evaluado mediante la medición de la actividad de la Nos, luego de haber inyectado una dosis luteolítica de PGF2alpha (3mug/kg) a ratas en estadio medio (día 5) y tardío (día 9) del desarrollo luteal. Los resultados confirmaron nuestra hipótesis; no se observó un efecto en el estadio medio del desarrollo del Cl, pero en la fase final se encontró un aumento en la actividad de la enzima Nos en aquellos animales que habían recibido la dosis mencionada de PGF2alpha.