Rhinovirus is an important pathogen in upper and lower respiratory tract infections in Mexican children.

BACKGROUND: Most of the studies characterizing the incidence of rhinovirus (RV) have been carried out in hospitalized children and in developed countries. In those studies, RV-C has been associated with more severe respiratory tract infections than RV species A and B. In this study we determined the frequency and diversity of RV strains associated with upper and lower respiratory tract infections (URTI, LRTI) in Mexico, and describe the clinical characteristics of the illness associated with different RV species. METHODS: A prospective surveillance of 526 and 250 children with URTI and LRTI was carried out. Respiratory samples were analyzed by RT-PCR for viruses. The 5' untranslated region of the RV genome was amplified and sequenced. RESULTS: In the case of URTI, 17.5% were positive for RV, while this virus was found in 24.8% of LRTI. The RV species was determined in 73 children with URTI: 61.6% were RV-A, 37% RV-C and, 1.4% RV-B; and in 43 children with LRTI: 51.2% were RV-A, 41.8% RV-C, and 7% RV-B. No significant differences in clinical characteristics were found in patients with RV-A or RV-C infections. A high genetic diversity of RV strains was found in both URTI and LRTI. CONCLUSIONS: Both RV-A and RV-C species were frequently found in hospitalized as well as in outpatient children. This study underlines the high prevalence and genetic diversity of RV strains in Mexico and the potential severity of disease associated with RV-A and RV-C infections.

SCCmec types and pvl gene in methicillin-resistant Staphylococcus aureus strains from children hospitalized in a tertiary care hospital in Mexico.

BACKGROUND: The aim of this study was to determine the prevalence, SCCmec types, presence of the Panton-Valentine leukocidin (PVL) gene, and susceptibility to antibiotics of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from hospitalized children. METHODS: From August 2009 to September 2011, 291 S. aureus strains were isolated from normally sterile body sites, of which 190 (65%) were MRSA. One hundred and two of the MRSA strains were genetically evaluated. SCCmec genotypes were identified by M-PCR and the PVL gene (pvl) by end-point PCR. Resistance to erythromycin, rifampicin, clindamycin, and trimethoprim-sulfamethoxazole (SXT) was assessed by Kirby-Bauer disk diffusion method in accordance with the Clinical and Laboratory Standards Institute guidelines of 2012. RESULTS: Of the 102 strains evaluated, 97 (95%) were SCCmec type II, 5 (5%) were SCCmec type IVa, and all (100%) were pvl-negative. Resistance to erythromycin, clindamycin, rifampicin, and SXT was 97%, 95%, 0%, and 0%, respectively. CONCLUSIONS: The prevalence of hospital-acquired MRSA was high. SCCmec type II was predominant and the pvl gene appeared not to play any role in the virulence of the MRSA strains from hospitalized children.

Sexual risk behavior and type of sexual partners in transnational indigenous migrant workers.

Indigenous migrant workers (IMWs) have a high vulnerability to HIV and STDs due to poverty and marginalization. This study examined factors associated with sexual risk behavior (SRB) according to type of partner in transnational young male IMWs at a sugar cane agro-industrial complex in western Mexico. A total of 192 sexually active IMWs were recruited from four laborer shelters to participate in a sexual partner survey. The IMWs were interviewed about their sexual partners and practices over the last 12 months during which it emerged that they had had a total of 360 sexual partners. Multiple linear regression analyses were performed to identify factors related to SRB in 222 main (spouse, mistress and girlfriend) and 138 casual partners (colleague, friend, casual encounter and sex worker). Results showed a significantly higher SRB score with casual partners. For the main partner regression model, prior exposure to HIV- and STD-preventive information and sexual intercourse with higher employment status partners (formal workers vs. self-employed in informal activities and unemployed) were associated with lower SRB scores, but if the sexual relations occurred in Mexico (vs. the U.S.), the SRB scores increased. For the casual partner model, the practice of survival sex (sex in exchange for basic needs), sexual relations in Mexico (vs. the U.S.), and being a circular migrant (person traveling for temporary work to return home when the contract is over) were related to higher SRB scores. Findings support the implementation of preventive interventions using different messages depending on the type of partners, main or casual, within the labor migrant context.

[Consensus on the clinical and microbiologic diagnosis of Bordetella pertussis, and infection prevention. Expert Group on Pertussis Vaccination]. / Consenso para el diagnóstico clínico y microbiológico y la prevención de la infección por Bordetella pertussis. Grupo de expertos en vacunación contra tos ferina.

Pertussis continues to be responsible for a significant disease burden worldwide. Although immunization practices have reduced the occurrence of the disease among children, waning vaccine- and infection-induced immunity still allows the disease to affect adolescents and adults who, in turn, can transmit the disease to non-immunized or partially immunized infants. This document is the result of a meeting in Mexico City of international experts who analyzed recent medical information in order to establish the current status of the epidemiology, diagnosis and surveillance of pertussis and, especially, the value of the dTpa booster dose in adolescents and adults as a pertussis prevention strategy in Mexico.

[Spread of S. pyogenes to the caretakers and relatives from nasopharyngeal carrier children attended in a day care center]. / Diseminación de S. pyogenes al personal y familiares de niños portadores nasofaríngeos de una guardería.

OBJECTIVE: to evaluate the prevalence of nasopharyngeal S. pyogenes (SP) carriers among children attending a day care center (DCC) and the spread of specific clones (SC) among caretakers and relatives. METHODS: nasopharyngeal cultures were performed in children with SP positive culture (306), family members (51) and caretakers (73) at time 0, and four and seven months later. Differences among SP strains were determined. Descriptive statistics and Fisher exact test were performed. RESULTS: SP prevalence in carrier children, caretakers and relatives was 10, 0 and 4 %. Three pairs of children, from two different classrooms, shared SP strains SC I, II and III. A clone VII was isolated from a relative. In the second survey, the SP prevalence was 4, 0 and 0 %. Two classmates shared clone I and other two from a different classroom shared clone V. In the third, the prevalence was 2, 4 and 14 %. Strains of clones II and VII were isolated from children. A sister of one child, who did not attend to DCC, was a carrier of clone II found in her brother. Clone III was isolated in one caretaker. CONCLUSIONS: the SP carrier prevalence was similar to other reports. The sharing of identical clones of SP was found among children in close physical contact.

[Risk factors associated to neonatal cross-infection]. / Factores de riesgo asociados a sepsis neonatal nosocomial.

BACKGROUND: Late-onset sepsis (occurring after 3 days of age) either cross-infection (CI) or perinatal is the first cause of morbidity and mortality in neonatal intensive care units (NICU) around the world. Our objective was to determine the current incidence of CI risk factors in neonates admitted to the NICU of the Hospital Civil de Guadalajara during a 9-month period. METHODS: A case-control study with 114 newborns; 38 with CI and 76 controls. Odds ratio with 95 % confidence interval were calculated. RESULTS: Associated risk factors were total parenteral nutrition (OR = 16.54, CI = 6.30-43.39, p < 0.001); weight < 1000 g (OR = 7.33, CI = 2.15-25.01, p < 0.001); intravascular catheter (OR = 6.79, CI = 2.68-17.00, p < 0.001); gestational age < 30 weeks (OR = 4.54, CI = 1.61-12.81, p < 0.003); intratracheal intubation and mechanical ventilation with (OR = 6.98, CI = 2.94-16.5, p < 0.001). CONCLUSIONS: Total parenteral nutrition and weight < 1000 g showed the greatest association with cross-infection; in this study, male gender was not a risk factor.

Serotypes and susceptibility of Streptococcus pneumoniae strains isolated from children in Mexico.

OBJECTIVE: To identify serotypes and susceptibility of S. pneumoniae strains from 48 children with invasive infections and 50 carriers. MATERIAL AND METHODS: Typing was performed by the Quellung reaction and susceptibility by Kirby-Bauer and Etest according to CLSI standards. RESULTS: Of 31 meningeal strains, serotypes 19F, 3, 6B, 14 and 23F were predominant. Resistance to penicillin and STX was 16 and 58%, respectively; of 17 invasive non-meningeal strains, serotypes 19F and 3 were predominant and resistance to penicillin and SXT was 0 and 82%, respectively; of carrier strains, serotypes 6A, 6B, 19F and 23F were predominant. CONCLUSIONS: A 10-valent conjugate vaccine could offer a better coverage for meningeal strains.

[Multivariate model to predict Streptococcus pyogenes tonsillitis]. / Modelo multivariado para predecir amigdaltis estreptócócica.

OBJECTIVE: to develop a multivariate model to predict the Streptococcus pyogenes isolation in patients with acute tonsillitis. METHODS: cross-sectional analytic study on patients with acute tonsillitis without a recent history of antimicrobial consumption. We evaluated 14 signs and 18 symptoms. A pharyngeal culture was realized on 5% sheep blood agar. Group A streptococci was identified by standard methods. STATISTICAL ANALYSIS: sensitivity, specificity, predictive values, chi2, Fisher's exact test, crude and adjusted odds ratio (OR) with 95% CI using dichotomical logistic regression with direct method and Hosmer and Lemeshow-goodness-fit test. RESULTS: there were 213 participants, 37% were males; a mean age of 14.9 years. We isolated Streptococcus pyogenes in 15%, and 84 % of them had received antimicrobials. We identified signs and symptoms associated with Streptococcus pyogenes isolation: painful swallowing (OR=4.45, 95% CI = 1.13-17.53); tonsils with exudates (OR=3.20, 95% CI = 1.22-8.43); smelly breath (OR=2.78, 95% CI = 1.09-7.10); painful neck nodes (OR=2.70, 95% CI = 1.05-6.96). The presence of nasal symptoms was a protective factor (OR=0.25, 95% CI = 0.09-0.71). CONCLUSIONS: the prevalence of Streptococcus pyogenes tonsillitis was similar to other reports. We found signs and symptoms associated to Streptococcus pyogenes isolation that allowed us to elaborate a decision algorithm.

[Deficient identification of signs and symptoms in Streptoccoci amigdalitis]. / Identificación de signos y síntomas pivote en amigdalitis estreptocócica.

OBJECTIVE: To evaluate the degree of identification of main signs and symptoms of streptococcal pharyngitis by resident doctors, general practitioners, family physicians and pediatricians. MATERIALS AND METHODS: A prospective, cross-sectional and comparative study was done. A validated questionnaire was applied including the following topics: social demographic, main signs and symptoms, clinical cases; and clinical pictures. We interviewed resident doctors (n = 40), general physicians (n = 21), family physicians (n = 35) and pediatricians (n = 19) from different institutions (SSa, ISSSTE, IMSS) in Guadalajara, Mexico, from March to August 2005. Scores were interpreted as very good, good, regular and poor, and these scores were related with the specialty and clinical years of experience. STATISTICAL ANALYSIS: chi2, student t test and linear regression. RESULTS: This study included 115 physicians between 22 to 60 years old (mean = 39) and with 0 to 31 (mean = 10) clinical years of experience. Regarding the conceptual identification of main signs and symptoms, tonsil exudates were recognized by 33 to 61% of physicians, and a clinical case of streptococcal tonsillitis was recognized by 50 to 70%. A clinical picture of tonsil caseum was misinterpreted as streptococcal tonsillitis by 13 to 35% of the physicians. There was no association between years of clinical experience and the scores obtained in clinical cases (r = 0.20) or clinical pictures (r = 0.09). CONCLUSIONS: The clinical identification of streptococcal tonsillitis was regular to poor among all the interviewed physicians, and there had no correlation with the years of clinical experience. The reinforcement in teaching to recognize the key signs and symptoms of streptococcal tonsillitis at medical school would result in better recognition, more rational use of antimicrobials and reduction in health institutions costs.

Estimación de la Relación Costo-Efectividad de las Vacunas Neumocócicas Conjugadas Prevenar-13 y Synflorix®, Utilizadas en Los Programas de Vacunación de Población Infantil Mexicana.

OBJECTIVE: To estimate the cost effectiveness associated with the use of pneumococcal conjugated vaccines, Prevenar-13 and Synflorix®, in the Mexican pediatric population. METHODS: The cost-effectiveness ratio of instrumenting vaccination programs based upon the use of Prevenar-13 and Synflorix® in the Mexican pediatric population was estimated by using a Markov's simulation model. The robustness of the conclusions reached on cost-effectiveness for both vaccines was assayed through an univariate and probabilistic sensitivity analysis that included all of the parameters considered by the model. RESULTS: Synflorix® was dominant over Prevenar-13 in the cost-utility analysis; the former generated more quality-adjusted life years at a lower cost and with a lower incremental cost-utility ratio. Based on the cost-effective analysis, Prevenar-13 generated more life years gained but at a higher cost. The use of Prevenar-13 originated a higher incremental cost-effectiveness ratio and, therefore, it was not cost-effective as compared with Synflorix®. CONCLUSIONS: Even though the simulations for Prevenar-13 and Synflorix® revealed both of them to be cost-effective when used to instrument pediatric vaccination campaigns in Mexico, Synflorix® had a better cost-utility/effectiveness profile. In addition, although Prevenar-13 and Synflorix® produced equivalent health outcomes, the overall analysis predicted that Synflorix® would save 360 million Mexican pesos, as compared with Prevenar-13.

[Antibody development and frequency of events temporarily associated with measles and rubella vaccines among university health personnel in Jalisco]. / Desarrollo de anticuerpos y frecuencia de eventos temporalmente asociados a las vacunas contra el sarampión y rubéola en personal de salud universitario de Jalisco.

OBJECTIVE: To evaluate the seroprevalence, seroconversion, anamnesic response and events temporally associated with immune status pre and post immunization with measles and rubella vaccine in health personnel from a public University in Guadalajara, Mexico. MATERIAL AND METHODS: We carried out a prospective, longitudinal and comparative study from May to June 2000 among 120 healthy volunteers. Informed consent was obtained from all participants. We administered measles (Schwarz) and rubella (RA 27/3) vaccines. Weekly phone calls during six weeks were recorded from each volunteer to assess local and systemic events temporally associated with immunization non attributable to any other disease. Serum samples were obtained before and after vaccination in 75 volunteers. Antibodies against measles and rubella were measured by an enzyme immunoassay kit (Behring) with cut-off points of 300mUI/mL 8UI/mL respectively. Statistical analysis included mean, standard deviation and paired Student's t-test (P < 0.05). RESULTS: 105/120 participants (87.5%) were followed during 6 weeks. 87.4% were health personnel and 44.6% were males. The age range was 17-71 years (median = 21). We found a prior history of measles in 57.1%. Local events included pain, heat, redness and induration and were reported by 4/105. Systemic events such as fever, exanthema, pain in joints and arthritis was reported by 9/105. The proportion of study subjects with protective antibodies against measles and rubella prior to vaccination was 90.7 and 94.7% respectively. Both groups reached 100% after vaccination. CONCLUSIONS: The proportion of non-immune health personnel was low and similar to other reports. However, the potential spread of measles and rubella virus from a non-immunized infected health care provider could be amplified by the number of patients seen daily during the peak period of 3-5 days. The vaccination of health personnel should be encouraged.

[Prevalence of Streptococcus algalactiae serotype III in pregnant women]. / Prevalencia de Streptococcus agalactiae del serotipo III en embarazadas.

BACKGROUND: Group B streptococcus, or Streptococcus agalactiae, is a grampositive coccus related to infections in the mother and the newborn during peri and postnatal period. OBJECTIVE: To describe the prevalence of S. agalactiae serotype III and the susceptibility to antimicrobials in strains isolated from pregnant women. MATERIAL AND METHODS: Cultures from vagina, rectum, and urine were taken from 123 high risk pregnant women, who attended to a Gynecology and obstetrics hospital from June 1st to August 30, 2000. Samples were cultured on 5% sheep blood agar and selective broth. For comparison purposes, we also studied 25 S. agalactiae strains from non-pregnant women isolated from January 2000 to August 2001. Serotyping was performed by latex agglutination and susceptibility testing by Kirby Bauer method. RESULTS: The prevalence of S. agalactiae carriers in pregnant women was 13% and the serotypes were: I (58.8%), II (29.4%), III (5.9%) and non typeable (5.9%). Serotypes from non-pregnant women were: I (68%), II (4%), and III (28%). In both groups, the intermediate resistance to penicillin was 17.6 and 12%, whereas for ceftriaxione was 17.6 and 20% respectively. Resistance to both clindamycin and erythromycin was lower than 4%. CONCLUSIONS: The prevalence of S. agalactiae in pregnant women was low and similar to other studies reported in Mexico. Serotype I was the most frequently isolated. Resistance to clindamycin and erythromycin was low, whereas intermediate resistance to penicillin and ceftriaxone was high. The low prevalence of both Streptococcus agalactiae and associated infections in Mexico could be related to racial factors or immunity due to early exposure to that bacterium.

Is there still room for novel viral pathogens in pediatric respiratory tract infections?

Viruses are the most frequent cause of respiratory disease in children. However, despite the advanced diagnostic methods currently in use, in 20 to 50% of respiratory samples a specific pathogen cannot be detected. In this work, we used a metagenomic approach and deep sequencing to examine respiratory samples from children with lower and upper respiratory tract infections that had been previously found negative for 6 bacteria and 15 respiratory viruses by PCR. Nasal washings from 25 children (out of 250) hospitalized with a diagnosis of pneumonia and nasopharyngeal swabs from 46 outpatient children (out of 526) were studied. DNA reads for at least one virus commonly associated to respiratory infections was found in 20 of 25 hospitalized patients, while reads for pathogenic respiratory bacteria were detected in the remaining 5 children. For outpatients, all the samples were pooled into 25 DNA libraries for sequencing. In this case, in 22 of the 25 sequenced libraries at least one respiratory virus was identified, while in all other, but one, pathogenic bacteria were detected. In both patient groups reads for respiratory syncytial virus, coronavirus-OC43, and rhinovirus were identified. In addition, viruses less frequently associated to respiratory infections were also found. Saffold virus was detected in outpatient but not in hospitalized children. Anellovirus, rotavirus, and astrovirus, as well as several animal and plant viruses were detected in both groups. No novel viruses were identified. Adding up the deep sequencing results to the PCR data, 79.2% of 250 hospitalized and 76.6% of 526 ambulatory patients were positive for viruses, and all other children, but one, had pathogenic respiratory bacteria identified. These results suggest that at least in the type of populations studied and with the sampling methods used the odds of finding novel, clinically relevant viruses, in pediatric respiratory infections are low.

[Respiratory tract infections in indigenous migrant Mexican day-laboring families' children]. / Infecciones respiratorias en niños migrantes indígenas de familias jornaleras mexicanas.

OBJECTIVE: Identifying factors associated with respiratory tract infection in indigenous migrant day-laborer families'children living in the sugarcane sector in Colima, Mexico. METHODS: This was a cross-sectional study. Having given their informed consent, 71 mothers were interviewed for compiling pertinent sociodemographic data and a history of respiratory tract infection in their children during the harvest period 2010-2011. Anthropometry for 176 children aged 0-14 years was recorded and they were clinically examined for upper and lower respiratory tract infection. Frequencies, percentages, Chi-square, odds ratio (crude and adjusted) and 95 % confidence intervals were calculated for the resulting data. RESULTS: 52.3 % of the children in the sample had a history of respiratory infection occurring during the last six months. Respiratory infection rates were statistically significant regarding temporary residence in shelters/hostels. The factors associated with a background of infection were being aged less than four years (AOR 4.06 (2.03-8.09) 95 % CI) and having been involved in temporary residence in a shelter,thereby leading to more overcrowding and an increased use of wood stoves for cooking (AOR 1.92 (1.01-3.63) 95 % CI). CONCLUSION: Indigenous migrant day-laboring families'children are vulnerable to respiratory infection. Prevention programs should target their activities by age-group, emphasizing younger children, and promote improved sanitary conditions in the shelters.

Measurement of Haemophilus influenzae type a capsular polysaccharide antibodies in cord blood sera.

We measured anti-Haemophilus influenzae type a capsular polysaccharide serum immunoglobulin G antibodies in cord blood sera from Mexican (n = 68) and Chilean mothers (n = 72) by enzyme-linked immunosorbent assay. Measurable antibodies were found in 79.3% of samples. Immunoglobulin G antibodies correlated with serum bactericidal activity (r = 0.66). This enzyme-linked immunosorbent assay can be used for the evaluation of adaptive immune responses to Haemophilus influenzae type a and serosurveillance studies in populations at risk.

Phenotypes and genotypes of erythromycin-resistant Streptococcus pyogenes strains isolated from invasive and non-invasive infections from Mexico and the USA during 1999-2010.

OBJECTIVE: To compare the prevalence, phenotypes, and genes responsible for erythromycin resistance among Streptococcus pyogenes isolates from Mexico and the USA. METHODS: Eighty-nine invasive and 378 non-invasive isolates from Mexico, plus 148 invasive, 21 non-invasive, and five unclassified isolates from the USA were studied. Susceptibilities to penicillin, erythromycin, clindamycin, ceftriaxone, and vancomycin were evaluated according to Clinical and Laboratory Standards Institute (CLSI) standards. Phenotypes of erythromycin resistance were identified by triple disk test, and screening for mefA, ermTR, and ermB genes was carried out by PCR. RESULTS: All isolates were susceptible to penicillin, ceftriaxone, and vancomycin. Erythromycin resistance was found in 4.9% of Mexican strains and 5.2% of USA strains. Phenotypes in Mexican strains were 95% M and 5% cMLS; in strains from the USA, phenotypes were 33.3% iMLS, 33.3% iMLS-D, and 33.3% M. Erythromycin resistance genes in strains from Mexico were mefA (95%) and ermB (5%); USA strains harbored ermTR (56%), mefA (33%), and none (11%). In Mexico, all erythromycin-resistant strains were non-invasive, whereas 89% of strains from the USA were invasive. CONCLUSIONS: Erythromycin resistance continues to exist at low levels in both Mexico and the USA, although the genetic mechanisms responsible differ between the two nations. These genetic differences may be related to the invasive character of the S. pyogenes isolated.

Clinical outcomes in Mexican children with febrile acute upper respiratory tract infections: no impact of antibiotic therapy.

OBJECTIVE: To compare the clinical outcomes (duration of signs and symptoms) and the microbiology in Mexican children with non-complicated febrile upper respiratory tract infections (URI), with and without the use of antibiotics. METHODS: We conducted a prospective cohort study from September 2006 to July 2007. The study population consisted of 880 children aged 6 months to 5 years 11 months, attending four community daycare centers run by the Instituto Mexicano del Seguro Social (IMSS) and three non-IMSS daycare centers. Children with a febrile URI were enrolled before receiving any antimicrobials and were followed up for two weeks. Duration of the fever, cough, runny nose, stuffy nose, irritability, loss of appetite, tiredness, and diarrhea, and isolation of Haemophilus influenzae,Streptococcus pneumoniae, and Streptococcus pyogenes were compared in those children who received antibiotic treatment and those who did not receive antibiotics. RESULTS: During the study period, a total of 145 out of 880 children were enrolled, and among those enrolled, 85/145 (59%) children received antibiotics. There was no significant difference in the duration of the signs and symptoms evaluated in the two groups. Although the proportions of S. pneumoniae, H. influenzae, and S. pyogenes isolated in children with and without antibiotics were comparable, those in whom we isolated S. pneumoniae had both a significantly longer episode of URI, as well as longer lasting diarrhea. Similarly, children receiving trimethoprim-sulfamethoxazole treatment experienced significantly longer durations of fever and diarrhea. CONCLUSIONS: The mean duration of signs and symptoms and the microbiological isolates of children with febrile URI were comparable among children treated with or without antibiotics, with the exception of a longer duration of URI and diarrhea in those children with an S. pneumoniae isolate. Our findings suggest that in our population, most cases of febrile URI are caused by viral infections, and demonstrate that antibiotics should not be used routinely in children with non-complicated febrile URI.

Infecciones respiratorias en niños migrantes indígenas de familias jornaleras mexicanas / Respiratory tract infections in indigenous migrant Mexican day-laboring families' children

Objetivo Identificar factores asociados a infecciones de vías respiratorias en niños migrantes indígenas de familias jornaleras del sector cañero en Colima, México. Métodos Estudio transversal descriptivo. Previo consentimiento informado, se entrevistaron 71 madres sobre aspectos sociodemográficos y antecedentes de infecciones de vías respiratorias en sus niños, durante el período decosecha 2010-2011. Se realizó antropometría a 176 niños de 0-14 años y se revisaron clínicamente en busca de infecciones de vías respiratorias superiores e inferiores. Se calcularon frecuencias, porcentajes, Ji cuadrado,razones de momios (cruda y ajustada) e intervalos de confianza del 95 %. Resultados El 52,3 % de los niños tuvieron antecedentes de infecciones respi-ratorias en los últimos seis meses. Los porcentajes de infecciones respiratorias tuvieron diferencias significativas por albergues de residencia. Los factores asociados al antecedente de infección fueronla edad menor a cuatro años (RMA=4,06, IC 95 % (2,03-8,09)) y la residencia temporal en un albergue conmayor hacinamiento en sus cuartos y mayor uso de fogones de leña para cocinar (RMA=1,92, IC95 % (1,01-3,63)). Conclusión Los niños migrantes indígenas de familias jornaleras son vulnerables a las infecciones de vías respiratorias. Los programas preventivos deben segmentar sus acciones por grupos de edad, con énfasis en los niños menores, y favorecer la mejora en las condiciones de salubridad en los albergues.(AU)

Objective Identifying factors associated with respiratory tract infection in indigenous migrant day-laborer families'children living inthe sugarcane sector in Colima, Mexico. Methods This was a cross-sectional study. Having given theirinformed consent, 71 mothers were interviewed for compiling pertinentsociodemographic data and a history of respiratory tract infection in their children during the harvest period 2010-2011. Anthropometry for 176 children aged 0-14 years was recorded and they were clinically examinedfor upper and lower respiratory tract infection. Frequencies, percentages, Chi-square, odds ratio (crude and adjusted) and 95 % confidence intervals were calculated for the resulting data. Results 52.3 % of the children in the sample had a history of respiratory infection occurring during the last six months. Respiratory infectionrates were statistically significant regarding temporary residence in shelters/hostels. The factors associated with a background of infection were being aged less than four years (AOR 4.06 (2.03-8.09) 95 % CI) and having been involved in temporary residence in a shelter,thereby leading tomore overcrowding and an increased use of wood stoves for cooking (AOR 1.92 (1.01-3.63) 95 % CI). ConclusionIndigenous migrant day-laboring families'children are vulnerable to respiratory infection. Prevention programs should target their activities by age-group, emphasizing younger children, and promote improved sanitary conditions in the shelters.(AU)