Acceptance of a third COVID-19 vaccine dose, vaccine interchangeability, and clinical trial enrolment among parents of children 12-17 years in Lima, Perú.

Objectives: To characterize factors associated with parental willingness for their children participation in a COVID-19 vaccine trial, use of different COVID-19 vaccines and acceptance of a third vaccine dose. Methods: Parents of children aged 12-17 years in Lima, Perú were asked to complete an online questionnaire via social networks, from November 9, 2021, to April 23, 2022. We calculated crude and adjusted prevalence ratios with 95% confidence intervals to compare factors with the mentioned outcomes. Results: From 523 parents responding, 374 completed the survey. 90.4% would give their children a third vaccine dose, 36.6% would allow their children participation in a COVID-19 vaccine clinical trial, and 33.2% would accept different vaccine brands between doses. Parental belief that COVID-19 vaccine studies met quality standards was associated with acceptance of a third booster dose (adjusted PR 3.25; 95% CI1.57-6.74; p = 0.002), enrolment in a COVID-19 clinical trial (adjusted PR 4.49; 95% CI1.25-16.06; p = 0.02), and acceptance of different COVID-19 vaccine brands between doses (adjusted PR 10.02; 95% CI1.40-71.95; p = 0.02). Conclusion: Most parents would accept a third vaccine booster dose, approximately a third would participate in COVID-19 vaccine trials. Believing COVID-19 vaccines studies fulfilled quality standards was associated with the study outcomes. It is necessary to inform about the rigorous processes for the development of COVID-19 vaccines to generate confidence in parents to accept these vaccine-related outcomes.

Ultra-processed foods consumption and health-related outcomes: a systematic review of randomized controlled trials.

Introduction: The increase in ultra-processed foods (UPFs) intake has raised concerns about its impact on public health. Prospective observational studies have reported significant associations between higher intake of UPFs and adverse health outcomes. The aim of this study is to determine whether these associations could be confirmed in randomized controlled trials (RCTs). Methods: We conducted a systematic review to analyze the evidence on the effects of UPFs intake on health. A systematic search was conducted in Medline, Embase, Web of Science, Scopus, LILACS, and CENTRAL up to April 22, 2024. RCTs in English, Spanish, and Portuguese evaluating the health effects of interventions to modify UPFs intake were included. The certainty of evidence was determined using the GRADE methodology. Results: Three educational intervention studies and one controlled feeding trial were included, evaluating the effect of reducing the consumption of UPFs (455 participants, median follow-up, 12 weeks). No significant effects were observed in 30 out of the 42 outcomes evaluated. The controlled feeding trial in adults with stable weight showed a reduction in energy intake, carbohydrates, and fat (low certainty of evidence), as well as in body weight, total cholesterol, and HDL cholesterol (moderate certainty of evidence). In the educational intervention studies, a reduction in body weight and waist circumference was observed (low certainty of evidence) in women with obesity, as well as improvement in some dimensions of quality of life (very low certainty of evidence). No significant changes were observed in children and adolescents with obesity, while in overweight pregnant women, the consumption of UPFs was not reduced, so the observed benefits could be attributed to other components of the intervention. Conclusion: Interventions aimed at reducing the consumption of UPFs showed benefits on some anthropometric and dietary intake outcomes, although significant effects were not observed for most of the evaluated outcomes. The limited number and significant methodological limitations of the studies prevent definitive conclusions. Further well-designed and conducted RCTs are needed to understand the effects of UPF consumption on health.Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023469984.

Effect of reducing saturated fat intake on cardiovascular disease in adults: an umbrella review.

Introduction: Our objective was to explore the effect of the reduction of saturated fat (SAF) intake on cardiovascular disease, mortality and other health-related outcomes in adults. Methods: We conducted an umbrella review, searching Medline, Scopus, EMBASE, Cochrane Library, and LILACS databases for systematic reviews from December 1, 2012, to December 1, 2022. We have included meta-analyses of randomized controlled trials (RCTs) and cohort studies. We extracted effect sizes (95%CI), heterogeneity (I 2), and evidence quality rating based on the population, intervention, comparator, and outcomes. Results: 21 meta-analyses were included (three were from RCTs, and 18 were from cohort studies). Among meta-analyses of RCTs, 15 of the 45 associations were significant. The effect of reduction in SAF intake on combined cardiovascular events (RR 0.79, 95%CI 0.66-0.93) was graded as having moderate certainty of evidence. We found no effect on all-cause mortality, cardiovascular mortality, cancer deaths, and other cardiovascular events. Among meta-analyses of cohort studies, five of the 19 associations were significant. There was an increase in coronary heart disease mortality (HR 1.10, 95% CI 1.01-1.21) and breast cancer mortality (HR 1.51, 95% CI 1.09-2.09) in participants with higher SFA intake compared to reduced SFA. We found no effect on all-cause mortality, cardiovascular mortality, and other cardiovascular events. Conclusion: This umbrella review found the reduction in SAF intake probably reduces cardiovascular events and other health outcomes. However, it has little or no effect on cardiovascular mortality and mortality from other causes. More high-quality clinical trials with long-term follow-up are needed.Systematic review registration: CRD42022380859.

Short-, mid-, and long-term complications after multisystem inflammatory syndrome in children over a 24-month follow-up period in a hospital in Lima-Peru, 2020-2022.

Objective: To determine the short-, mid-, and long-term complications after multisystem inflammatory syndrome in children (MIS-C) over a 24-month follow-up period in a hospital in Lima, Peru, 2020-2022, and to explore differences according to the immunomodulatory treatment received and type of SARS-CoV-2 virus circulating. Methods: Ambispective 24-month follow-up study in children <14 years of age diagnosed with MIS-C at the Hospital Nacional Edgardo Rebagliati Martins (HNERM). Results: A total of 62 children were admitted with MIS-C. The most common short-term complications and serious events were intensive care unit (ICU) admission, invasive mechanical ventilation (IMV) due to respiratory failure, and shock; predominantly during the second pandemic wave (lambda predominance) and in children that received intravenous immunoglobulin (IVIG) plus a corticosteroid. Two patients died during the first wave due to MIS-C. During prospective follow-up (median of 24 months; IQR: 16.7-24), only 46.7% of patients were followed for >18-24 months. Of the total, seven (11.3%) patients were identified with some sequelae on discharge. Among the 43 remaining children, sequelae persisted in five (11.6%) cases (neurological, hematological, and skin problems). Six patients (13.9%) presented with new onset disease (hematologic, respiratory, neurological, and psychiatric disorders). One patient died due to acute leukemia during the follow-up period. None of them were admitted to the ICU or presented with MIS-C reactivation. Two patients presented persistence of coronary aneurysm until 8- and 24-month post-discharge. Conclusion: In our hospital, children with MIS-C frequently developed short-term complications and serious events during the acute phase, with less frequent complications in the mid- and long-term. More studies are required to confirm these findings.

Pooling of six respiratory samples for the detection of SARS-CoV-2: A validation and cost study in a cohort in Lima, Peru.

Background: The continuous evolution of the SARS-CoV-2 pandemic has led to a high demand for diagnostic testing and major shortages in testing materials, especially in low- and middle-income countries. As an alternative to testing individual samples, pooling of respiratory samples has been suggested. Previous studies have assessed performance of pooling, mainly using nasopharyngeal samples for the detection of SARS-CoV-2, but few studies have examined the performance of pooling the more practical nasal swabs or saliva samples. Objective: To evaluate the sensitivity, specificity, and potential cost reduction of pooling of nasal swab (NS) and saliva (SL) samples for detection of SARS-CoV-2 in a community-based cohort study in Lima, Peru. Study design: A prospective cohort study was conducted in a community setting in San Juan de Lurigancho, Lima-Peru. NS and SL samples were collected from 132 participants twice-a-week for a 2-month period. Pools of 2 to 12 samples of the same type, from participants of the same household, were tested by RT-PCR. After pooled testing, all individual samples from positive pools and all individual samples from randomly chosen negative pools were evaluated. For assessment of diagnostic performance, pool testing results were compared with results from individual testing, which served as reference, and concordance in pooled and individual test detections was evaluated. Laboratory costs for both types of samples and testing were compared. Results: A total of 2008 NS and 2002 SL samples were collected from 132 study participants. We tested 329 NS and 333 SL pools. The mean pool size for NS and SL pools was 6.22 (SD = 0.92) and 6.39 (SD = 1.71), respectively. Using individual testing as reference, NS pooling of 6 had a sensitivity and specificity of 94% and 100%, respectively, with kappa of 0.97 (CI 95%: 0.93-1.00). The corresponding values for SL pooling of 6 were 83%, 100%, and 0.90 (CI 95%: 0.83-0.97). Compared with individual testing, pooling resulted in a cost reduction of 74.8% for NS and 72.4% for SL samples. Conclusions: Pooling easy-to-collect respiratory samples, especially NS, demonstrated very high diagnostic performance for detection of SARS-CoV-2 with substantial cost savings. This approach could be considered in large population screening programs, especially in LMIC.

Association between nasopharyngeal colonization with multiple pneumococcal serotypes and total pneumococcal colonization density in young Peruvian children.

OBJECTIVES: We examined the association of nasopharyngeal (NP) pneumococcal co-colonization (>1 pneumococcal serotype) and pneumococcal density in young Peruvian children enrolled in a prospective cohort study. METHODS: NP swabs collected monthly from children aged <3 years during both asymptomatic and acute respiratory illness (ARI) periods underwent culture-enriched microarray for pneumococcal detection and serotyping and lytA polymerase chain reaction for density assessment. We examined the serotypes commonly associated with co-colonization and the distribution of densities by co-colonization, age, current ARI, and other covariates. The association of co-colonization and pneumococcal density was assessed using a multivariable mixed-effects linear regression model, accounting for repeated measures and relevant covariates. RESULTS: A total of 27 children contributed 575 monthly NP samples. Pneumococcus was detected in 302 of 575 (53%) samples, and co-colonization was detected in 61 of these 302 (20%). The total densities were higher during ARI than non-ARI periods and lowest among the youngest children, increasing with age. In the multivariable analysis, there was no significant association between pneumococcal density and co-colonization (coefficient estimate 0.22, 95% confidence interval 0.11-0.55; reference: single-serotype detections). Serotypes 23B and 19F were detected significantly more frequently as single isolates. CONCLUSION: Pneumococcal co-colonization was common and not associated with increased pneumococcal density. Differential propensity for co-colonization was observed among individual serotypes.

Characteristics of pediatric patients hospitalized with COVID-19 during the third wave (omicron variant) at a referral hospital in Peru. / Características de los pacientes pediátricos hospitalizados con COVID-19 durante la tercera ola (variante ómicron) en un hospital de referencia del Perú.

OBJECTIVES.: Motivation for the study. There are few reports on the clinical experience of the population infected with the omicron variant of COVID-19 in Latin America, particularly in pediatric population. Main findings. There was a rapid increase in the number of hospitalizations compared to previous waves, mainly due to respiratory conditions; most patients progressed favorably. Antibiotics and corticosteroids were the most used drugs. Implications. Studying the characteristics of children hospitalized during the third wave of COVID-19 in Peru may increase the knowledge of how the omicron variant affects this population group, which will allow comparisons with possible new waves or diseases.

SARS-CoV-2 infections in households in a peri-urban community of Lima, Peru: A prospective cohort study.

BACKGROUND: We assessed the prevalence and incidence of SARS-CoV-2 infections in a prospective study of households in Lima, Peru. METHODS: Households with a child, a young adult 18-50 years, and an adult age >50 years in peri-urban Lima were followed with twice-a-week household visits during a 2-month period. Nasal swabs and saliva specimens were collected twice weekly, and nasopharyngeal swabs were collected weekly from each participant, regardless of symptoms. Laboratory-confirmed SARS-CoV-2 infection was defined by two RT-PCR tests from any of the collected specimens within a week. Blood samples collected at enrollment and end of follow-up were tested with rapid serological tests. We calculated the prevalence and incidence of laboratory-confirmed SARS-CoV-2 infections. RESULTS: We enrolled 132 participants from 44 households: 44 children, 44 young adults, and 44 older adults. A total of 13 SARS-CoV-2 infections were detected in eight households, for an overall period prevalence of 9.85% (95% confidence interval [CI]: 5.35-16.25). Most (61.54%) infections were symptomatic. Eight of 11 (72.73%) SARS-CoV-2 detections corresponded to the Lambda variant. During 218.79 person-months at risk of follow-up, there were six new SARS-CoV-2 infections detected (2.74 per 100 person-month, 95% CI: 1.25-6.04). At enrollment, 59 of 128 participants tested had positive SARS-CoV-2 IgG serology (46.09%, 95% CI: 37.25-55.12). Five of six new infections occurred among participants with negative baseline serology. CONCLUSIONS: We demonstrated high incidence of SARS-CoV-2 infections in households, especially among subjects without evidence of prior infection, most of them not detected by the Ministry of Health system.

Assessing the Impact of Acute Respiratory Illnesses on the Risk of Subsequent Respiratory Illness.

BACKGROUND: Whether acute respiratory illnesses (ARIs), often associated with virus detection, are associated with lower risk for subsequent ARI remains unclear. We assessed the association between symptomatic ARI and subsequent ARI in young children. METHODS: In a prospective cohort of Peruvian children <3 years, we examined the impact of index ARI on subsequent ARI risk. Index ARI were matched with ≤3 asymptomatic observations and followed over 28 days. We compared risk of subsequent ARI between groups using conditional logistic regression adjusting for several covariates, accounting for repeat observations from individual children. RESULTS: Among 983 index ARI, 339 (34%) had an ARI event during follow-up, compared with 876/2826 (31%) matched asymptomatic observations. We found no significant association of index ARI and subsequent ARI risk during follow-up overall (adjusted odds ratio [aOR], 1.10; 95% confidence interval [CI], .98-1.23) or when limited to index ARI with respiratory viruses detected (aOR, 1.03; 95% CI, .86-1.24). Similarly, when the outcome was limited to ARI in which viruses were detected, no significant association was seen (aOR, 1.05; 95% CI, .87-1.27). CONCLUSIONS: ARIs were not associated with short-term protection against subsequent ARI in these children. Additional longitudinal studies are needed to understand drivers of recurrent ARI in young children.

A novel real-time RT-PCR assay for influenza C tested in Peruvian children.

BACKGROUND: Influenza C virus (ICV) is associated with acute respiratory illness. Yet ICV remains under recognized, with most previous studies using only culture to identify cases. OBJECTIVES: To develop a sensitive and specific real-time RT-PCR assay for ICV that allows for rapid and accurate detection in a clinical or research setting. STUDY DESIGN: Multiple ICV sequences obtained from GenBank were analyzed, including 141 hemagglutinin-esterase (HE), 106 matrix (M), and 97 nucleoprotein (NP) sequences. Primers and probes were designed based on conserved regions. Multiple primer-probe sets were tested against multiple ICV strains. RESULTS: The ICV M and NP genes offered the most conserved sequence regions. Primers and probes based on newer sequence data offered enhanced detection of ICV, especially for low titer specimens. An NP-targeted assay yielded the best performance and was capable of detecting 10-100 RNA copies per reaction. The NP assay detected multiple clinical isolates of ICV collected in a field epidemiology study conducted in Peru. CONCLUSIONS: We report a new real-time RT-PCR assay for ICV with high sensitivity and specificity.

Nasopharyngeal Pneumococcal Density and Evolution of Acute Respiratory Illnesses in Young Children, Peru, 2009-2011.

We examined nasopharyngeal pneumococcal colonization density patterns surrounding acute respiratory illnesses (ARI) in young children in Peru. Pneumococcal densities were dynamic, gradually increasing leading up to an ARI, peaking during the ARI, and decreasing after the ARI. Rhinovirus co-infection was associated with higher pneumococcal densities.

Biomonitoring Human Exposure to Household Air Pollution and Association with Self-reported Health Symptoms - A Stove Intervention Study in Peru.

BACKGROUND: Household air pollution (HAP) from indoor biomass stoves contains harmful pollutants, such as polycyclic aromatic hydrocarbons (PAHs), and is a leading risk factor for global disease burden. We used biomonitoring to assess HAP exposure and association with self-reported symptoms in 334 non-smoking Peruvian women to evaluate the efficacy of a stove intervention program. METHODS: We conducted a cross-sectional study within the framework of a community randomized control trial. Using urinary PAH metabolites (OH-PAHs) as the exposure biomarkers, we investigated whether the intervention group (n=155, with new chimney-equipped stoves) were less exposed to HAP compared to the control group (n=179, with mostly open-fire stoves). We also estimated associations between the exposure biomarkers, risk factors, and self-reported health symptoms, such as recent eye conditions, respiratory conditions, and headache. RESULTS: We observed reduced headache and ocular symptoms in the intervention group than the control group. Urinary 2-naphthol, a suggested biomarker for inhalation PAH exposure, was significantly lower in the intervention group (GM with 95% CI: 13.4 [12.3, 14.6] µg/g creatinine) compared to control group (16.5 [15.0, 18.0] µg/g creatinine). Stove type and/or 2-naphthol was associated with a number of self-reported symptoms, such as red eye (adjusted OR with 95% CI: 3.80 [1.32, 10.9]) in the past 48h. CONCLUSIONS: Even with the improved stoves, the biomarker concentrations in this study far exceeded those of the general populations and were higher than a no-observed-genotoxic-effect-level, indicating high exposure and a potential for increased cancer risk in the population.

Spatial and Temporal Spread of Acute Viral Respiratory Infections in Young Children Living in High-altitude Rural Communities: A Prospective Household-based Study.

BACKGROUND: Few studies have described patterns of transmission of viral acute respiratory infections (ARI) in children in developing countries. We examined the spatial and temporal spread of viral ARI among young children in rural Peruvian highland communities. Previous studies have described intense social interactions in those communities, which could influence the transmission of viral infections. METHODS: We enrolled and followed children <3 years of age for detection of ARI during the 2009 to 2011 respiratory seasons in a rural setting with relatively wide geographic dispersion of households and communities. Viruses detected included influenza, respiratory syncytial virus (RSV), human metapneumovirus and parainfluenza 2 and 3 viruses (PIV2, PIV3). We used geospatial analyses to identify specific viral infection hot spots with high ARI incidence. We also explored the local spread of ARI from index cases using standard deviational ellipses. RESULTS: Geospatial analyses revealed hot spots of high ARI incidence around the index cases of influenza outbreaks and RSV outbreak in 2010. Although PIV3 in 2009 and PIV2 in 2010 showed distinct spatial hot spots, clustering was not in proximity to their respective index cases. No significant aggregation around index cases was noted for other viruses. Standard deviational ellipse analyses suggested that influenza B and RSV in 2010, and human metapneumovirus in 2011 spread temporally in alignment with the major road network. CONCLUSIONS: Despite the geographic dispersion of communities in this rural setting, we observed a rapid spread of viral ARI among young children. Influenza strains and RSV in 2010 had distinctive outbreaks arising from their index cases.

Immunogenicity and Safety of Yellow Fever Vaccine (Stamaril) When Administered Concomitantly With a Tetravalent Dengue Vaccine Candidate in Healthy Toddlers at 12-13 Months of Age in Colombia and Peru: A Randomized Trial.

BACKGROUND: Dengue and yellow fever (YF) viruses are closely related members of the Flaviviridae family. Given the inherent similarities between the YF vaccine and dengue vaccine (CYD-TDV) candidate, it is possible that the latter could interfere with the response to the licensed YF vaccine when coadministered. METHODS: In this randomized, observer-blind, controlled, phase III trial, conducted in Colombia and Peru, 787 toddlers were administered YF vaccine concomitantly with CYD-TDV (group 1) or placebo (group 2), followed by CYD-TDV after 6 and 12 months. YF and dengue neutralizing antibody titers were determined using a 50% plaque reduction neutralization test. Noninferiority was demonstrated if the lower limit of the 2-sided 95% confidence interval of the difference in seroconversion rates [(YF + CYD-TDV) - YF alone] was greater than -10%. The safety of both vaccines was also assessed. RESULTS: Concomitant administration of YF with either CYD-TDV or placebo yielded YF seroconversion rates of 100.0% and 99.7%, respectively. The difference in YF seroconversion rates between the 2 groups was 0.33% (95% confidence interval:0.98; 1.87), demonstrating that the immune response against YF administered concomitantly with CYD-TDV was noninferior to YF administered with placebo. After 2 injections of CYD-TDV, the percentage of participants with dengue titres ≥10 (1/dil) for the 4 dengue serotypes were 91.2%-100% for group 1 and 97.2%-100% in group 2. There were no safety concerns during the study period. CONCLUSIONS: Concomitant administration of YF vaccine with CYD-TDV has no relevant impact on the immunogenicity or safety profile of the YF vaccine.

Bacterial Density, Serotype Distribution and Antibiotic Resistance of Pneumococcal Strains from the Nasopharynx of Peruvian Children Before and After Pneumococcal Conjugate Vaccine 7.

BACKGROUND: Pneumococcal conjugate vaccines (PCV) have decreased nasopharyngeal carriage of vaccine types but little data exist from rural areas. We investigated bacterial density, serotype distribution and antibiotic resistance of pneumococcal strains within the nasopharynx of young children in the Peruvian Andes, 2 years after PCV7 was introduced. METHODS: Pneumococcal strains were isolated from a subset of 125 children from our Peruvian cohort, who entered the study in 2009 and had pneumococcus detected in the nasopharynx in both 2009 and during follow-up in 2011. Strains were Quellung serotyped and tested for susceptibility to antibiotics. Bacterial density was determined by quantitative polymerase chain reaction. RESULTS: The prevalence of PCV7 strains decreased from 48% in 2009 to 28.8% in 2011, whereas non-PCV7 types increased from 52% to 71.2% (P = 0.002). There was a 3.5-fold increase in carriage of serotype 6C in 2011 (P = 0.026). Vaccination with PCV7 did not affect pneumococcal density in children colonized by a PCV7 type but did increase density in those colonized with a non-PCV7 type. Antibiotic resistance did not change after vaccine introduction; strains were nonsusceptible to tetracycline (97.2%), trimethoprim-sulfamethoxazole (56.4%), penicillin (34%), erythromycin (22.4%), chloramphenicol (18.8%) and clindamycin (12.4%). CONCLUSIONS: Serotype replacement was observed post-PCV7 vaccination with a concomitant, not previously recognized, increased nasopharyngeal density.

Comparative analysis of antimicrobial resistance in enterotoxigenic Escherichia coli isolates from two paediatric cohort studies in Lima, Peru.

BACKGROUND: Antibiotic resistance is increasing worldwide, being of special concern in low- and middle-income countries. The aim of this study was to determine the antimicrobial susceptibility and mechanisms of resistance in 205 enterotoxigenic Escherichia coli (ETEC) isolates from two cohort studies in children <24 months in Lima, Peru. METHODS: ETEC were identified by an in-house multiplex real-time PCR. Susceptibility to 13 antimicrobial agents was tested by disk diffusion; mechanisms of resistance were evaluated by PCR. RESULTS: ETEC isolates were resistant to ampicillin (64%), cotrimoxazole (52%), tetracycline (37%); 39% of the isolates were multidrug-resistant. Heat-stable toxin producing (ETEC-st) (48%) and heat-labile toxin producing ETEC (ETEC-lt) (40%) had higher rates of multidrug resistance than isolates producing both toxins (ETEC-lt-st) (21%), p<0.05. Only 10% of isolates were resistant to nalidixic acid and none to ciprofloxacin or cefotaxime. Ampicillin and sulfamethoxazole resistance were most often associated with blaTEM (69%) and sul2 genes (68%), respectively. Tetracycline resistance was associated with tet(A) (49%) and tet(B) (39%) genes. Azithromycin inhibitory diameters were ≤15 mm in 36% of isolates, with 5% of those presenting the mph(A) gene. CONCLUSIONS: ETEC from Peruvian children are often resistant to older, inexpensive antibiotics, while remaining susceptible to ciprofloxacin, cephalosporins and furazolidone. Fluoroquinolones and azithromycin remain the drugs of choice for ETEC infections in Peru. However, further development of resistance should be closely monitored.

Respiratory Viral Detections During Symptomatic and Asymptomatic Periods in Young Andean Children.

BACKGROUND: Viruses are commonly detected in children with acute respiratory illnesses (ARIs) and in asymptomatic children. Longitudinal studies of viral detections during asymptomatic periods surrounding ARI could facilitate interpretation of viral detections but are currently scant. METHODS: We used reverse transcription polymerase chain reaction to analyze respiratory samples from young Andean children for viruses during asymptomatic periods within 8-120 days of index ARI (cough or fever). We compared viral detections over time within children and explored reverse transcription polymerase chain reaction cycle thresholds (CTs) as surrogates for viral loads. RESULTS: At least 1 respiratory virus was detected in 367 (43%) of 859 samples collected during asymptomatic periods, with more frequent detections in periods with rhinorrhea (49%) than those without (34%, P < 0.001). Relative to index ARI with human rhinovirus (HRV), adenovirus (AdV), respiratory syncytial virus (RSV) and parainfluenza virus detected, the same viruses were also detected during 32, 22, 10 and 3% of asymptomatic periods, respectively. RSV was only detected 8-30 days after index RSV ARI, whereas HRV and AdV were detected throughout asymptomatic periods. Human metapneumovirus and influenza were rarely detected during asymptomatic periods (<3%). No significant differences were observed in the CT for HRV or AdV during asymptomatic periods relative to ARI. For RSV, CTs were significantly lower during ARI relative to the asymptomatic period (P = 0.03). CONCLUSIONS: These findings indicate that influenza, human metapneumovirus, parainfluenza virus and RSV detections in children with an ARI usually indicate a causal relationship. When HRV or AdV is detected during ARI, the causal relationship is less certain.

Incidence and Risk Factors for Respiratory Syncytial Virus and Human Metapneumovirus Infections among Children in the Remote Highlands of Peru.

INTRODUCTION: The disease burden and risk factors for respiratory syncytial virus (RSV) and human metapneumovirus (MPV) infections among children living in remote, rural areas remain unclear. MATERIALS AND METHODS: We conducted a prospective, household-based cohort study of children aged <3 years living in remote rural highland communities in San Marcos, Cajamarca, Peru. Acute respiratory illnesses (ARI), including lower respiratory tract infection (LRTI), were monitored through weekly household visits from March 2009 through September 2011. Nasal swabs collected during ARI/LRTI were tested for RSV, MPV, and other respiratory viruses using real-time RT-PCR. Incidence rates and rate ratios were calculated using mixed effects Poisson regression. RESULTS: Among 892 enrolled children, incidence rates of RSV and MPV ARI were 30 and 17 episodes per 100 child-years, respectively. The proportions of RSV and MPV ARI that presented as LRTI were 12.5% and 8.9%, respectively. Clinic visits for ARI and hospitalizations were significantly more frequent (all p values <0.05) among children with RSV (clinic 41% and hospital 5.3%) and MPV ARI (38% and 3.5%) when compared with other viral infections (23% and 0.7%) and infections without virus detected (24% and 0.6%). In multivariable analysis, risk factors for RSV detection included younger age (RR 1.02, 95% CI: 1.00-1.03), the presence of a smoker in the house (RR 1.63, 95% CI: 1.12-2.38), residing at higher altitudes (RR 1.93, 95% CI: 1.25-3.00 for 2nd compared to 1st quartile residents; RR 1.98, 95% CI: 1.26-3.13 for 3rd compared to 1st quartile residents). Having an unemployed household head was significantly associated with MPV risk (RR 2.11, 95% CI: 1.12-4.01). CONCLUSION: In rural high altitude communities in Peru, childhood ARI due to RSV or MPV were common and associated with higher morbidity than ARI due to other viruses or with no viral detections. The risk factors identified in this study may be considered for interventional studies to control infections by these viruses among young children from developing countries.

A household-based study of contact networks relevant for the spread of infectious diseases in the highlands of Peru.

BACKGROUND: Few studies have quantified social mixing in remote rural areas of developing countries, where the burden of infectious diseases is usually the highest. Understanding social mixing patterns in those settings is crucial to inform the implementation of strategies for disease prevention and control. We characterized contact and social mixing patterns in rural communities of the Peruvian highlands. METHODS AND FINDINGS: This cross-sectional study was nested in a large prospective household-based study of respiratory infections conducted in the province of San Marcos, Cajamarca-Peru. Members of study households were interviewed using a structured questionnaire of social contacts (conversation or physical interaction) experienced during the last 24 hours. We identified 9015 reported contacts from 588 study household members. The median age of respondents was 17 years (interquartile range [IQR] 4-34 years). The median number of reported contacts was 12 (IQR 8-20) whereas the median number of physical (i.e. skin-to-skin) contacts was 8.5 (IQR 5-14). Study participants had contacts mostly with people of similar age, and with their offspring or parents. The number of reported contacts was mainly determined by the participants' age, household size and occupation. School-aged children had more contacts than other age groups. Within-household reciprocity of contacts reporting declined with household size (range 70%-100%). Ninety percent of household contact networks were complete, and furthermore, household members' contacts with non-household members showed significant overlap (range 33%-86%), indicating a high degree of contact clustering. A two-level mixing epidemic model was simulated to compare within-household mixing based on observed contact networks and within-household random mixing. No differences in the size or duration of the simulated epidemics were revealed. CONCLUSION: This study of rural low-density communities in the highlands of Peru suggests contact patterns are highly assortative. Study findings support the use of within-household homogenous mixing assumptions for epidemic modeling in this setting.

Fecal contamination of food, water, hands, and kitchen utensils at the household level in rural areas of Peru.

The study described in this article evaluated sources of contamination of children's food and drinking water in rural households in the highlands of Peru. Samples from children's meals, drinking water, kitchen utensils, and caregivers' and children's hands were analyzed for total coliforms and E. coli counts using Petrifilm EC. Thermotolerant coliforms in water were measured using DelAgua test kits while diarrheagenic E. coli was identified using polymerase chain reaction methods (PCR). Thermotolerant coliforms were found in 48% of all water samples. E. coli was found on 23% of hands, 16% of utensils, and 4% of meals. Kitchen cloths were the item most frequently contaminated with total coliforms (89%) and E. coli (42%). Diarrheagenic E. coli was found in 33% of drinking water, 27% of meals, and on 23% of kitchen utensils. These findings indicate a need to develop hygiene interventions that focus on specific kitchen utensils and hand washing practices, to reduce the contamination of food, water, and the kitchen environment in these rural settings.