Effect of UV-C disinfection and copper plating on healthcare-associated infections in a NICU with high ESBL infections.

INTRODUCTION: Healthcare-associated infections (HCAIs) in neonates are frequent and highly lethal, in particular those caused by extended spectrum beta-lactamase (ESBL) producing bacteria. We evaluated the beneficial effects of ultraviolet C (UV-C) disinfection and copper adhesive plating on HCAIs in the Neonatal Intensive Care Unit (NICU) of a third level paediatric hospital in Mexico City, both in combination of hand-hygiene (HH) and prevention bundles. METHODS: All NICU patients were included. There were 4 periods (P): P1: HH monitoring and prevention bundles; P2: P1+UV-C disinfection; P3: P2+Copper adhesive plating on frequent-contact surfaces and P4: Monitoring of P3 actions. RESULTS: 552 neonates were monitored during 15,467 patient days (PD). HCAI rates decreased from 11.03/1000 PD in P1 to 5.35/1000 PD in P4 (p=0.006). HCAIs with bacterial isolates dropped from 5.39/1000 PD in PI to 1.79/1000 PD in P4 (p=0.011). UV-C and copper were associated with significant HCAI prevention (RR 0.49, CI95% 0.30-0.81, p=0.005) and with lesser HCAIs with bacterial isolates (RR 0.33, CI95% 0.14-0.77, p=0.011). CONCLUSIONS: Copper adhesive plating combined with UV-C disinfection were associated with a drop in HCAI rates and with the elimination of ESBL-caused HCAIs. Hence, we propose that these strategies be considered in MDRO proliferation preventions.

Frequency of respiratory virus-associated infection among children and adolescents from a tertiary-care hospital in Mexico City.

Acute respiratory infections (ARIs) are a major cause of morbidity and mortality among children. The causative pathogens show geographic and seasonal variations. We retrospectively evaluated the frequency and seasonality of respiratory pathogens in children and adolescents (age: 0-19 years) with ARIs treated between January 1, 2021, and March 31, 2022, at a single center in Mexico. Out of 2400 patients, 1,603 were diagnosed with SARS-CoV-2 infection and 797 were diagnosed with other common respiratory pathogens (CRPs). Of the 797 patients, 632 were infected with one CRP and 165 with > 2 CRPs. Deaths occurred only in SARS-CoV-2-infected patients. Rhinovirus/Enterovirus, respiratory syncytial virus B, and parainfluenza virus 3 were the most prevalent in cases with single and multiple infections. CRP showed a high frequency between autumn and winter of 2021, with higher incidence of hospitalization compared to COVID-19. The main comorbidities were immunosuppression, cardiovascular disease (CD), and asthma. The frequency of CRPs showed a downward trend throughout the first half of 2021. CRPs increased in single- and co-infection cases between the fourth and fifth waves of COVID-19, probably due to decreased nonpharmaceutical interventions and changes in diagnostic tests. Age, cyanosis (symptom), and immunosuppression (comorbidity) were found to differentiate between SARS-CoV-2 infection and CRP infection.

Behavior of immunoglobulin G antibodies for SARS-COV-2 in Mexican pediatric patients with comorbidities: a prospective comparative cohort study.

Background: More than two years after the pandemic of COVID-19 caused by the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) there is a great lack of information. The presence of immunoglobulin G (IgG) have been related with disease severity. Patients with comorbidities could develop more severe infection; however, the evaluation of the humoral response in pediatric population are needed especially in patients with comorbidities. Our aim was to describe the behavior of IgG in pediatric patients and to know if there is a difference between patients with comorbidities. Methods: A prospective comparative cohort study was carried out in a single center from June 2020 to January 2021, with a follow-up of 6 months. The study included all the subjects with confirmatory test for SARS-CoV-2 from 1 month to 17 years 11 months, the follow-up of the disease's evolution and measurement of IgG antibodies was collected. We obtained the clinical data, and comorbidities like arterial hypertension, diabetes, obesity, and cancer, the initial symptoms were recorded as well as the evolution regarding the severity of COVID-19 and the need for hospitalization, intensive care unit or mechanical ventilation. The follow up was carried out through medical consultation with an appointment every month that included direct interrogation, examination, and peripheral blood collection for the IgG quantification. The antibodies detection was done through peripheral blood and chemiluminescence microparticle immunoassay. Results: A total of 237 patients with positive polymerase chain reaction (PCR) for SARS-COV-2 were included, of which 147 presented IgG antibodies (62%), 112 (76%) without comorbidity and 35 (24%) with comorbidities, by the sixth month only 2.7% continue with positive antibody measurements. Patients with comorbidities reach higher IgG levels than patients without comorbidities the basal titters were: 5.17 for patients without comorbidities vs. 6.96 for the group with comorbidities (P<0.001). Conclusions: We found an association between the presence of comorbidities and high levels of IgG units in pediatric patients with COVID-19. Additionally, patients with more severe course of the disease have higher levels of IgG and by the third month less than 35% have immunity.

Knowledge, attitudes, perceptions, and COVID-19 hesitancy in a large public university in Mexico city during the early vaccination rollout.

BACKGROUND: Vaccination against COVID-19 is a primary tool for controlling the pandemic. However, the spread of vaccine hesitancy constitutes a significant threat to reverse progress in preventing the disease. Studies conducted in Mexico have revealed that vaccination intention in Mexico among the general population ranges from 62 to 82%. OBJECTIVE: To know the prevalence of COVID-19 vaccine hesitancy and associated factors among academics, students, and administrative personnel of a public university in Mexico City. METHODS: We administered an online survey investigating sociodemographic aspects, knowledge, attitudes, practices, and acceptance/hesitancy regarding the COVID-19 vaccine. Using generalized linear Poisson models, we analyzed factors associated with vaccine hesitancy, defined as not intending to be vaccinated within the following six months or refusing vaccination. RESULTS: During May and June 2021, we studied 840 people, prevalence of vaccine hesitancy was 6%. Hesitancy was significantly associated with fear of adverse effects, distrust of physician's recommendations, lack of knowledge regarding handwashing, age younger than 40 years, refusal to use face masks, and not having received influenza vaccination during the two previous seasons. CONCLUSIONS: Vaccine hesitancy in this population is low. Furthermore, our results allowed us the identification of characteristics that can improve vaccine promotion.

Allowing access to parents/caregivers into COVID-19 hospitalization areas does not increase infections among health personnel in a pediatric hospital.

Background: At the beginning of the current COVID-19 pandemic, it became critical to isolate all infected patients, regardless of their age. Isolating children has a negative effect on both, them and their parents/caregivers. Nevertheless isolation was mandatory because of the potential risk that visitation might have on COVID-19 dissemination mostly among health personnel. Methods: From the starting of the COVID-19 pandemic in our pediatric hospital visits were forbidden. This 2 months period (April-May) was called P1. In June parents were allowed to visit (P2), under a visiting protocol previously published. Hospital workers were monitored for the presence of COVID-19 symptoms and tested for the infection when clinically justified. The positivity proportion and the relative risk (RR) of COVID-19 among the health personnel between periods were calculated. The caregivers were also followed up by phone calls. Results: Since April 2020 to November 2020, 2,884 health personnel were studied for 234 days, (318,146 workers days). Although the COVID-19/1,000 health personnel days rate decreased from one period to another (1.43 vs 1.23), no statistically significant differences were found. During P1, 16 patients with COVID-19 were treated. During the follow up none of the family members were infected/symptomatic in P1, while in P2, 6/129 (4.65%) were symptomatic or had a positive test. All of them initiated between 2 and 4 days after the patient's admission. As they also had some other infected family members it was not possible to ensure the source of infection. There were no statistically significant differences in the RR of COVID-19 in health personnel, (RR 1, 95% CI 0.69-1.06, p = 0.162). Conclusions: When safely implemented, allowing parents/caregivers to spend time with their hospitalized COVID-19 children does not increase the contagion risk for hospital workers or among themselves.

New Variants of Pseudomonas aeruginosa High-Risk Clone ST233 Associated with an Outbreak in a Mexican Paediatric Hospital.

Recent multidrug resistance in Pseudomonas aeruginosa has favoured the adaptation and dissemination of worldwide high-risk strains. In June 2018, 15 P. aeruginosa strains isolated from patients and a contaminated multi-dose meropenem vial were characterized to assess their association to an outbreak in a Mexican paediatric hospital. The strains were characterized by antibiotic susceptibility profiling, virulence factors' production, and biofilm formation. The clonal relationship among isolates was determined with pulse-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) sequencing. Repressor genes for the MexAB-OprM efflux pump were sequenced for haplotype identification. Of the strains, 60% were profiled as extensively drug-resistant (XDR), 33% as multidrug-resistant (MDR), and 6.6% were classified as sensitive (S). All strains presented intermediate resistance to colistin, and 80% were sensitive to aztreonam. Pyoverdine was the most produced virulence factor. The PFGE technique was performed for the identification of the outbreak, revealing eight strains with the same electrophoretic pattern. ST235 and ten new sequence types (STs) were identified, all closely related to ST233. ST3241 predominated in 26.66% of the strains. Twenty-five synonymous and seventeen nonsynonymous substitutions were identified in the regulatory genes of the MexAB-OprM efflux pump, and nalC was the most variable gene. Six different haplotypes were identified. Strains from the outbreak were metallo-ß-lactamases and phylogenetically related to the high-risk clone ST233.

Tracing COVID-19 Source of Infection Among Health Personnel in a Pediatric Hospital.

Health personnel (HP) have been universally recognized as especially susceptible to COVID-19. In Mexico, our home country, HP has one of the highest death rates from the disease. From the beginning of the SARS-CoV-2 pandemic, an office for initial attention for HP and a call center were established at a COVID-19 national reference pediatric hospital, aimed at early detection of COVID-19 cases and stopping local transmission. The detection and call center implementation and operation, and tracing methodology are described here. A total of 1,042 HP were evaluated, with 221 positive cases identified (7.7% of all HP currently working and 26% of the HP tested). Community contagion was most prevalent (46%), followed by other HP (27%), household (14%), and hospitalized patients (13%). Clusters and contact network analysis are discussed. This is one of the first reports that address the details of the implementation process of contact tracing in a pediatric hospital from the perspective of a hybrid hospital with COVID-19 and non-COVID-19 areas.

Screening for COVID-19 in Children Undergoing Elective Invasive Procedures.

OBJECTIVE: To report the frequency of asymptomatic infection with SARS-CoV-2 in pediatric patients undergoing invasive medical procedures in a tertiary pediatric hospital. METHODS: From June to October 2020, a SARS-CoV-2 real-time reverse-transcription polymerase chain reaction (rRT-PCR) test was performed for all pediatric patients scheduled to undergo an elective invasive procedure. None of the patients was symptomatic. The cycle threshold (Ct) values of the ORF1ab gene were recorded for all patients. RESULTS: A total of 700 patients were screened for SARS-CoV-2 infection. The median age was 5.7 y old. In total, 46.6% (n = 326) of the patients were male, and 53.4% (n = 374) were female. The most common underlying diseases were hemato-oncological (25.3%), gastrointestinal (24.9%), and genitourinary (10.3%). The main scheduled surgical-medical procedures were surgical treatment for acquired congenital diseases, biopsy sampling, local therapy administration, organ transplantation, and the placement of central venous catheters, among others. The SARS-CoV-2 rRT-PCR test was positive in 9.4% (66), and the median Ct value was 35.8. None of the patients developed COVID-19. CONCLUSIONS: The frequency of asymptomatic SARS-CoV-2 infection was detected in less than 10% of pediatric patients scheduled to undergo an elective invasive procedure in a tertiary hospital. This frequency is higher than those in reports from different countries.

Analysis of the Behaviour of Immunoglobulin G Antibodies in Children and Adults Convalescing From Severe Acute Respiratory Syndrome-Coronavirus-2 Infection.

The pandemic caused by SARS CoV-2 (COVID-19) has affected millions of people since 2020. There are clinical differences and in mortality between the adult and paediatric population. Recently, the immune response through the development of antibodies has gained relevance due to the risk of reinfection and vaccines' development. Objective: Was to compare the association of clinical history and the clinical presentation of the disease with the development of IgG antibodies against SARS-CoV-2 in paediatric and adult patients with a history of positive reverse transcriptase-polymerase chain reaction (RT-PCR) results. Methods: Cross-sectional observational study carried out in a Paediatric Hospital in Mexico City included patients under 18 years of age and health personnel with positive RT-PCR for COVID-19 comparing antibody expression. The development of specific IgG antibodies was measured, the presence of comorbidities, duration, and severity of symptoms was determined. Results: Sixty-one subjects (20 < 18 years and 41 > 18 years) were analysed. The median sample collection was 3 weeks. There were no differences in the expression of specific antibodies; no differences were shown according to the symptoms' severity. A positive correlation (r = 0.77) was demonstrated between the duration of symptoms and antibody levels. Conclusions: In conclusion, there is a clear association between the duration of the symptoms associated with SARS-CoV-2 infection and the IgG units generated in paediatric and adult patients convalescing from COVID-19.

Implementation of guidelines to integrate the caregiver as a coassistant of health-care personnel during the hospital stay of COVID-19 pediatric patients: adaptation in a Mexican public pediatric hospital.

This paper describes the experience in a public pediatric hospital when implementing the Mexican Health Ministry's recommendations on the inclusion and importance of a chosen caregiver during the hospitalization of a coronavirus disease 2019 (COVID-19) pediatric patient. The implementation includes the adjustments, observations, and limitations made in real practice and process. In conclusion, the value and benefits of the accompaniment of hospitalized children with COVID-19 by a primary or chosen caregiver are evidenced and supported by family-centered care. Furthermore, the recommendations mentioned result in comprehensive bio-psycho-social care for the benefit of pediatric patients.

Risk conditions in healthcare workers of a pediatric coronavirus disease center in Mexico City.

BACKGROUND: The new evere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is characterized by its high capacity to transmit. Health-care personnel is highly susceptible to becoming infected. This study aimed to determine the characteristics and known risk factors for contagion and severe outcomes of SARS-CoV-2 disease in health-care personnel of a pediatric coronavirus disease (COVID) center in Mexico City. METHODS: In the last week of March 2020 (at the beginning of phase 2 of the Ministry of Health's national campaign in Mexico), a study was conducted on healthcare workers of a pediatric COVID hospital in Mexico City. Using a virtual interview, we evaluated comorbidities, mobility, areas and functions where they carry out the activities, protection measures, contact history, and vaccination. According to their activities, healthcare workers were classified into the following areas: medical, nursing, other health-care personnel (researchers, nutritionists, rehabilitation, imaging, and laboratory), administrative, and other services. We compared the variables between the groups of healthcare workers with the X2 test. RESULTS: We included 812 participants. The mean age was 41 ± 11 years, and 33% were overweight or obese, 18% were over 60 years old, and 19% had high blood pressure. Medical and nursing personnel presented a higher proportion in the use of standard protection measures. CONCLUSIONS: Among healthcare workers, there are risk conditions for the development of complications in case of SARS-CoV-2 infection. Most medical and nursing personnel use standard protective measures.

Control of Methicillin-Resistant Staphylococcus aureus Strains Associated With a Hospital Outbreak Involving Contamination From Anesthesia Equipment Using UV-C.

Methicillin-resistant Staphylococcus aureus (MRSA) is considered an opportunistic pathogen in humans and is mainly associated with healthcare-associated infections (HCAIs). This bacterium colonizes the skin and mucous membranes of healthy people and causes frequent hospital outbreaks. The aim of this study was to perform molecular typing of the staphylococcal cassette chromosome mec (SCCmec) and agr loci as wells as to establish the pulsotypes and clonal complexes (CCs) for MRSA and methicillin-sensitive S. aureus (MSSA) outbreaks associated with the operating room (OR) at a pediatric hospital. Twenty-five clinical strains of S. aureus (19 MRSA and 6 MSSA strains) were recovered from the outbreak (patients, anesthesia equipment, and nasopharyngeal exudates from external service anesthesia technicians). These clinical S. aureus strains were mainly resistant to benzylpenicillin (100%) and erythromycin (84%) and were susceptible to vancomycin and nitrofurantoin. The SCCmec type II was amplified in 84% of the S. aureus strains, and the most frequent type of the agr locus was agrII, which was amplified in 72% of the strains; however, the agrI and agrIII genes were mainly detected in MSSA strains. A pulsed-field gel electrophoresis (PFGE) analysis grouped the 25 strains into 16 pulsotypes (P), the most frequent of which was P1, including 10 MRSA strains related to the anesthesia equipment, external service anesthesia technicians, and hospitalized patients. Multilocus sequence typing (MLST) identified 15 sequence types (STs) distributed in nine CCs. The most prevalent ST was ST1011, belonging to CC5, which was associated with the SCCmec type II and agrII type. We postulate that the external service anesthesia technicians were MRSA carriers and that these strains were indirectly transmitted from the contaminated anesthesia equipment that was inappropriately disinfected. Finally, the MRSA outbreak was controlled when the anesthesia equipment disinfection was improved and hand hygiene was reinforced.

Restructuring of a pediatric hospital in the face of the COVID-19 pandemic.

Overview of the pandemic In December 2019, a new virus named SARS-CoV-2 was reported in Wuhan province, China. The first case of COVID-19 in Mexico was confirmed on February 28, 2020, and the World Health Organization declared the pandemic on March 11.

Amino acid changes in HA and determinants of pathogenicity associated with influenza virus A H1N1pdm09 during the winter seasons 2015-2016 and 2016-2017 in Mexico.

Biennial H1N1pdm09 influenza A virus (IAV) epidemics have been associated with major severity of respiratory disease in Mexico. Atypically and in contrast with what happened in USA, Canada and Europe during 2017, an increase of infections due to the H1N1pdm09 pandemic virus instead of H3N2 was observed. In order to determine the viral contribution to severe acute respiratory disease, we characterized the pathogenicity determinants of IAV in Mexico during the 2015-2016 and 2016-2017 seasons. The RNA segments of 20 IAV samples were sequenced by NGS platform and phylogenetic analysis was conducted. The analysis of the hemagglutinin (HA) sequences established that all virus samples, except one, belong to clade (6B.1). The IAVs presented the substitution S162 N, which introduces a new glycosylation site in the hemagglutinin. We also found the D222 G substitution, which has been associated with a higher tropism towards the lower respiratory tract, and a non-reported insertion of one Ile in NS1 (Ile113). The IAVs from 2016 to 2017 in Mexico belong to the new clade 6B.1. The new glycosylation site in HA (S162 N) is a major change that may affect the efficacy of the current vaccine. We detected in several patients pathogenicity determinants associated with the severity of the respiratory disease.

The impact of tooth brushing versus tooth brushing and chlorhexidine application to avoid postoperative pneumonia in children.

BACKGROUND: The pathogenesis of postsurgical pneumonia is a complicated and multifactorial process, in which elements like oral bacteria, orotracheal intubation, and dental hygiene play an important role. The objective of this study was to evaluate the efficacy of 2 types of oral hygiene interventions in decreasing cases of postsurgical pneumonia. METHODS: In pediatric patients scheduled for surgery, a quasi-experimental study was carried out over a 2-year period to evaluate the efficacy of 2 types of oral hygiene interventions. There were 2 groups of intervention with 1 group for comparison. Intervention groups were tooth brushing by a dentist (intervention group 1) and dental brushing by parents + chlorhexidine gluconate (intervention group 2). Data from the year with no oral hygiene interventions were used as the baseline group. RESULTS: A total of 2,535 surgical procedures were followed. Baseline group incidence of postoperative pneumonia was 10 per 1,000 surgeries, 0.2 per 1,000 surgeries in the intervention group 1 (P = .04), and 0.8 per 1,000 surgeries in the intervention group 2. Intervention group 1 was protective against postoperative pneumonia (odds ratio, 0.06; P = .02; 95% confidence interval, 0.033-0.079), but there was no benefit with intervention group 2 (odds ratio, 0.87; P = .599; 95% confidence interval, 0.52-1.46). CONCLUSIONS: Dental brushing performed before surgery by a pediatric dentist was effective in reducing the incidence of postoperative pneumonia in pediatric patients.

Healthcare-Associated Pneumonia: Don't Forget About Respiratory Viruses!

Introduction: Healthcare-associated infections are an important cause of morbidity and mortality, are among the most common adverse events in healthcare, and of them, pneumonia is the most commonly reported. Our objective was to evaluate the incidence and clinical outcome of respiratory viruses in hospital-acquired pneumonia (HAP). Methods: This was a prospective cohort study, include patients aged between 0 and 18 who fulfilled Centers for Diseases Control and Prevention (CDC) criteria for HAP. Demographic and clinical data were obtained, and a nasopharyngeal swab specimen was taken for the detection of respiratory viruses. All included patients were monitored until discharge to collect data on the need for mechanical ventilation, intensive care unit (ICU) admission, and mortality. All-cause 30-day mortality was also ascertained. Results: Four thousand three hundred twenty-seven patients were followed for 42,658 patient-days and 5,150 ventilator-days. Eighty-eight patients (2.03%) met the CDC criteria for HAP, 63 patients were included, and clinical and epidemiological characteristics showed no statistically significant differences between patients with virus associated healthcare-associated pneumonia (VAHAP) and those with non-viral healthcare-associated pneumonia (NVHAP). At least one respiratory virus was detected in 65% [95% CI (53-77)] of episodes of HAP, with a single viral pathogen observed in 53.9% and coinfection with 2 viruses in 11.1% of cases. The outcome in terms of ICU admission, mechanical ventilation and the 30-day mortality did not show a significant difference between groups. Conclusions: In two-thirds of the patients a respiratory virus was identified. There was no difference in mortality or the rest of the clinical outcome variables. About half of the patients required mechanical ventilation and 10% died, which emphasizes the importance of considering these pathogens in nosocomial infections, since their identification can influence the decrease in hospital costs and be taken into account in infection control policies.

Everybody hands-on to avoid ESKAPE: effect of sustained hand hygiene compliance on healthcare-associated infections and multidrug resistance in a paediatric hospital.

PURPOSE: Hand hygiene is the most important strategy for preventing healthcare-associated infections (HCAIs); however, the impact of hand hygiene in middle-income countries has been poorly described. In this work, we describe the impact of the programme 'Let's Go for 100' on hand hygiene adherence, HCAIs rates and multidrug-resistant (MDR) bacteria, including the molecular typing of methicillin-resistant Staphylococcus aureus (MRSA) strains. METHODOLOGY: A multimodal, hospital-wide hand hygiene programme was implemented from 2013. 'Let's Go for 100' involved all healthcare workers and encompassed education, awareness, visual reminders, feedback and innovative strategies. Monthly hand hygiene monitoring and active HCAI surveillance were performed in every ward. Molecular typing of MRSA was analysed by pulsed-field gel electrophoresis (PFGE).Results/Key findings. Hand hygiene adherence increased from 34.9 % during the baseline period to 80.6 % in the last 3 months of this study. The HCAI rate decreased from 7.54 to 6.46/1000 patient-days (P=0.004). The central line-associated bloodstream infection (CLABSIs) rate fell from 4.84 to 3.66/1000 central line-days (P=0.05). Negative correlations between hand hygiene and HCAIs rates were identified. The attack rate of MDR-ESKAPE group bloodstream infections decreased from 0.54 to 0.20/100 discharges (P=0.024). MRSA pulsotypes that were prevalent during the baseline period were no longer detected after the 5th quarter, although new strains were identified. CONCLUSIONS: A multimodal hand hygiene programme in a paediatric hospital in a middle-income country was effective in improving adherence and reducing HCAIs, CLABSIs and MDR-ESKAPE bloodstream infections. Sustaining hand hygiene adherence at a level of >60 % for one year limited MRSA clonal transmission.

Influenza-like illness in healthcare personnel at a paediatric referral hospital: Clinical picture and impact of the disease.

INTRODUCTION: Healthcare personnel (HP) are frequently exposed to influenza and can be a source of transmission to patients and other workers, resulting in high-cost outbreaks for healthcare institutions. OBJECTIVES: To analyse the presentation of HP with influenza-like illness (ILI) and the differences between individuals with influenza confirmed by polymerase chain reaction (PCR) and those with a negative test. The secondary objective was to evaluate the duration of symptomatology and work absenteeism as well as the vaccination rate of HP at a paediatric referral hospital. METHODS: A cross-sectional, descriptive study was conducted at a paediatric referral hospital. Clinical and epidemiological data on HP with ILI were collected between January and April 2016. Nasopharyngeal swab for influenza PCR was obtained from one in every three workers with ILI. Telephone follow-up was conducted to document duration of symptoms, complications and absenteeism. RESULTS: A total of 164 ILI episodes were evaluated in 162 HP. A swab was obtained in 59 cases, and influenza was detected in 30 cases. The clinical picture of HP with confirmed influenza was similar to that of HP with a negative PCR. Arthralgia was more common in those with influenza (90% vs 58%), with a tendency towards statistical significance. No HP required hospitalization, and 78.5% were absent from work at least 1 day. CONCLUSIONS: Influenza causes significant morbidity and absenteeism among HP. Influenza infection was confirmed in only half of HP with an ILI on whom a PCR was performed, suggesting that other respiratory viruses can cause a similar pattern.