An outbreak of adenovirus type 7 in a residential facility for severely disabled children

Molecular subtypes of Adenovirus-associated acute respiratory infection outbreak in children in Northern Vietnam and risk factors of more severe cases

BACKGROUND

Under the pressure of Human Adenovirus (HAdV)-associated acute respiratory infection (ARI) outbreak in children in Northern Vietnam in the end of 2022, this study was initiated to identify the HAdV subtype(s) and examine the associated clinical features and risk factors of more severe cases.

METHODS

This study evaluated pediatric patients with ARI which had tested positive for HAdV between October and November 2022 using a multiplex real-time PCR panel. Nasopharyngeal aspirates or nasal swab samples were used for sequencing to identify HAdV subtypes. Clinical data were collected retrospectively.

RESULTS

Among 97 successfully sequenced samples, the predominant subtypes were HAdV-B3 (83%), HAdV-B7 (16%) and HAdV-C2 (1%). Lower respiratory manifestations were found in 25% of the patients of which 5% were diagnosed with severe pneumonia. There was no significant association between HAdV subtype and clinical features except higher white blood cell and neutrophil counts in those detected with HAdV-B3 (p<0.001). Co-detection of HAdV with ≥1 other respiratory viruses was found in 13/24(54%) of those with lower respiratory manifestations and 4/5(80%) of those with severe pneumonia (odds ratio (95% confidence interval) vs. those without = 10.74 (2.83, 48.17) and 19.44 (2.12, 492.73) respectively after adjusting for age, sex, birth delivery method, day of disease).

CONCLUSION

HAdV-B3 and HAdV-B7 were predominant in the outbreak. Co-detection of HAdV together with other respiratory viruses was a strong risk factor for lower respiratory tract illnesses and severe pneumonia. The findings advocate the advantages of multi-factor microbial panels for the diagnosis and prognosis of ARI in children.

The Impact of and Government Planning and Responses to Pandemics for People with Disability: A Rapid Review

Objective—To collate evidence on (1) the risk of infection for people with disability during infectious disease outbreaks and/or pandemics and (2) government responses and pandemic plans for people with disability. Methods—Through two rapid reviews, relevant peer-reviewed studies and grey literature published from 2002 onwards in the English language were identified. Data were synthesised narratively. Results—Aim 1: Of the 680 studies, two studies were included in the review. No grey literature was eligible for inclusion. The evidence regarding risk was inconclusive. Aim 2: Of the 50 studies, three peer-review studies, along with four government reports were included. The literature largely reported on measures being taken to maximise the prevention of transmission of COVID-19 for the general population, with only a few programs including people with disability. Conclusion—Overall, there is inconclusive evidence on the risk of infection for people with disability during infectious disease outbreaks and/or pandemics and the government preparedness and planning for disease outbreaks and/or pandemics largely exclude people with disability. From a population health perspective, during disease outbreaks and pandemics, including the COVID-19 pandemic, along with the general population, it is important for governments to include people with disability in their pandemic planning and response.

Epidemiology of Adenovirus Infections and Outcomes of Cidofovir Treatment in Severely Ill Children

BACKGROUND

An increase in human adenovirus (HAdV) infections among hospitalized children in Singapore was observed since 2013. Young age (<2 years) and significant comorbidities have been associated with severe HAdV infections which can result in significant morbidity and mortality. Cidofovir (CDV) has been used to treat severe HAdV infections despite limited data and efficacy.

METHODS

This is a retrospective, observational review of infants and children 1 month to 17 years of age with laboratory-confirmed severe HAdV infection, admitted to a pediatric tertiary care hospital in Singapore between January 2013 and September 2017. Severe infection was defined as requiring intensive care unit or high dependency care at any point during hospital admission. Clinical characteristics, potential risk factors for mortality, as well as the outcome of cases treated with CDV were examined.

RESULTS

A total of 1167 children were admitted for HAdV infection, of which 85 (7.3%) were severe. For severe infections, the median age was 1.5 years (interquartile range: 0.72-3.2 years). The majority had comorbidities (69.4%) and presented with pneumonia (32.9%). Genotypes HAdV-7 (29.4%) and HAdV-3 (27.0%) were the most common HAdV genotypes identified. Thirteen (15.3%) patients died. Patients who died had a higher proportion of existing neurologic comorbidity (46.2% vs. 13.9%; P = 0.014) and presentation with pneumonia (69.2% vs. 26.4%; P = 0.008) compared with survivors. Patients who presented with pneumonia had a higher risk of 30-day mortality (odds ratio 4.3, 95% confidence interval: 1.0-28.6; P < 0.05). CDV was administered to 17 (20%) children for mainly viremia (47.1%) and/or pneumonia (41.2%). Mortality rate was 41.2% for severe HAdV cases treated with CDV. A significant proportion of patients who died when compared with recovered patients presented with pneumonia (6 of 7, 85.7% vs 1 of 10, 10%; P = 0.004). All 8 patients who had viremia received CDV and survived.

CONCLUSIONS

Mortality can be high in pediatric patients with severe HAdV infections. HAdV-7 and HAdV-3 were the most common genotypes identified in our cohort with severe HAdV infection. Pneumonia is a potential risk factor for mortality in severe HAdV infections in our cohort. Early CDV administration may be considered in patients with severe HAdV infection and existing comorbidities but more studies are required.

A case series of children with adenovirus pneumonia: three-year experiences in a tertiary PICU

Background

Describe the outcome of adenovirus pneumonia in a pediatric intensive care unit (PICU) over a 3-year period, to identify the risk factors that may be associated with worse outcome.

Methods

A retrospective observational study was performed in the PICU of children’s hospital in Shanghai from July 2016 to June 2019. Sixty-seven children over 29 days to 14 years old with adenovirus pneumonia who were admitted to PICU with acute hypoxemic respiratory failure were included in this study. The primary outcome was hospital mortality, and secondary outcomes were hospital and PICU length of stay (LOS), and risk factors of worse outcome.

Results

Of 67 children with severe adenovirus pneumonia, the hospital mortality was 16.42% (11/67) and 28-day mortality was 14.93% (10/67). Median Pediatric Risk of Mortality III (PRISM III) score at admission was 13 (interquartile range [IQR], 10–15). Median PICU LOS stay was 11 days (8-18d) and hospital LOS was 22 days (16-31d). Among children with extracorporeal membrane oxygenation (n = 9), 6 cases survived and 3 cases died. The patients who need renal replacement therapy, neuromuscular blockade, parenteral nutrition, and packed red blood cell perfusion had higher hospital mortality (p < 0.001, p = 0.041, p = < 0.001, p = 0.012, respectively). Multivariate logistic analysis indicated that liver dysfunction and nosocomial infection were associated with high risk of mortality.

Conclusions

The hospital mortality of adenovirus pneumonia in our PICU was 16.42%. Patients complicated liver dysfunction and co-infection & nosocomial infection were associated with poor outcome.

Comparative study of clinical and epidemiological characteristics of major pediatric adenovirus epidemics in southern Taiwan

Background

Human adenoviruses (HAdV) are important pathogens of pediatric respiratory tract infections in Taiwan. There were two major HAdV epidemics in southern Taiwan in 2011 and 2014, respectively.

Methods

The demographic, clinical characteristics, and risk factors for hospitalization of pediatric patients with HAdV infection in the two outbreaks were retrospectively compared. The epidemic was defined as > 7% HAdV detection rate for six consecutive weeks. HAdV infection was defined as positive HAdV isolates from respiratory tract specimens. HAdV genotype was determined by PCR-based hexon gene sequencing.

Results

A total of 1145 pediatric patients were identified (635 cases in 2011; 510 cases in 2014). HAdV genotype 3 and 7 contributed to both epidemics, although the proportion of HAdV3 decreased significantly (64.7% in 2011 to 25.5% in 2014, p < 0.001) and was replaced by other genotypes (type 1, 4, and 6) in the 2014 epidemic. Among the hospitalized patients, there were more patients hospitalized with bronchopneumonia/or pneumonia in the 2011 epidemic (10.6% vs 5.1%, p < 0.001), while more patients hospitalized with acute pharyngitis/pharyngoconjunctival fever (63.9% vs. 38.6%, p < 0.001) in the 2014 epidemic. In both epidemics, hospitalized patients had higher WBC and C-reactive protein (CRP) levels than non-hospitalized patients. Using multivariate regression analysis, underlying disease and elevated CRP levels were independent risk factors for hospitalization in both epidemics.

Conclusion

There were significant differences in clinical, viral characteristics and risk factors of hospitalization between the 2011 and 2014 epidemics. Understanding changes in the epidemiological and clinical characteristics of HAdV epidemics is important from a public health perspective.

Aetiology and risks factors associated with the fatal outcomes of childhood pneumonia among hospitalised children in the Philippines from 2008 to 2016: a case series study

OBJECTIVE

Pneumonia remains the leading cause of hospitalisations and deaths among children aged <5 years. Diverse respiratory pathogens cause acute respiratory infections, including pneumonia. Here, we analysed viral and bacterial pathogens and risk factors associated with death of hospitalised children.

DESIGN

A 9-year case series study.

SETTING

Two secondary-care hospitals, one tertiary-care hospital and one research centre in the Philippines.

PARTICIPANTS

5054 children aged <5 years hospitalised with severe pneumonia.

METHODS

Nasopharyngeal swabs for virus identification, and venous blood samples for bacterial culture were collected. Demographic, clinical data and laboratory findings were collected at admission time. Logistic regression analyses were performed to identify the factors associated with death.

RESULTS

Of the enrolled patients, 57% (2876/5054) were males. The case fatality rate was 4.7% (238/5054), showing a decreasing trend during the study period (p<0.001). 55.0% of the patients who died were either moderately or severely underweight. Viruses were detected in 61.0% of the patients, with respiratory syncytial virus (27.0%) and rhinovirus (23.0%) being the most commonly detected viruses. In children aged 2-59 months, the risk factors significantly associated with death included age of 2-5 months, sensorial changes, severe malnutrition, grunting, central cyanosis, decreased breath sounds, tachypnoea, fever (≥38.5°C), saturation of peripheral oxygen <90%, infiltration, consolidation and pleural effusion on chest radiograph.Among the pathogens, adenovirus type 7, seasonal influenza A (H1N1) and positive blood culture for bacteria were significantly associated with death. Similar patterns were observed between the death cases and the aforementioned factors in children aged <2 months.

CONCLUSION

Malnutrition was the most common factor associated with death and addressing this issue may decrease the case fatality rate. In addition, chest radiographic examination and oxygen saturation measurement should be promoted in all hospitalised patients with pneumonia as well as bacteria detection to identify patients who are at risk of death.

Molecular characterization of human adenovirus associated with acute respiratory infections in Cameroon from 2011 to 2014

Background

Human adenoviruses (HAdVs) cause a wide range of diseases worldwide, including respiratory infections. Studies on HAdV molecular epidemiology are limited in Cameroon. The purpose of this study is to document the different types HAdV circulating in Cameroon in children with acute respiratory infections.

Methods

Nasopharyngeal swabs were collected from 811 children under 15 years from 2011 to 2014. The HAdV detection was assessed by semi-quantitative generic PCR r-gene®. The HAdV-positive samples were typed by amplification and sequencing of partial hexon gene and a real-time PCR. Demographic data were collected and analyzed. The infection and hospitalization risk factors were assessed thought the Chi-square test.

Results

A total of 137/220 HAdV-positive samples were amplified successfully. Six species of HAdV (Mastadenovirus A to F) were detected with B (108/220) and C (47/220) being the predominant strains. Hospitalization and age were significantly associated to HAdV-B and HAdV-C respectively. Phylogenetic analysis of HAdV-B3 virus (18) and B7 (5) shows a conserved and a significant temporal stability in relation to the reference sequence (99.1 to 100% of similarity).

Conclusion

This study reported HAdV species and types detected in children with acute respiratory infections in Cameroon between September 2011 and July 2014. These results support further evaluation of the spatio-temporal circulation pattern of HAdV species and types in Cameroon.

Human Neutrophil Defensin-1, -3, and -4 Are Elevated in Nasal Aspirates from Children with Naturally Occurring Adenovirus Infection

Background

Adenoviruses are highly contagious pathogens which cause respiratory disease particularly in children; they may induce severe disease in infants. Human neutrophil peptides (HNPs) have been found to exhibit antiadenoviral activity. Thus, we have investigated HNPs in nasal aspirates (NAs) of children suffering from adenoviral common cold.

Objective

To investigate the release of HNP-1–4 in adenovirus infection and the relationship with self-limiting upper respiratory tract infections.

Methods

Nasal aspirate samples (n=14) were obtained from children (aged 6–12 years) infected with adenovirus between June 2012 and December 2015. Control samples were taken 4 weeks after infection when the children were asymptomatic. Levels of HNPs were measured using an enzyme-linked immunosorbent assay (ELISA).

Results

There were increased levels of HNP-1, -3, and -4, but not HNP-2, in nasal aspirates (NAs) during adenovirus infections compared to healthy specimens (p ≤ 0.01). Moreover, there was also increase in the neutrophil count, which is a known cell source of HNPs.

Conclusion

Our finding supports the involvement of HNP-1, -3, and -4 in naturally occurring cold in children infected with adenovirus. Because of their known antiviral properties, it is tempting to hypothesize that HNPs might play a protective role in adenovirus-induced respiratory disease; however, this remains to be shown.

Clinical and virological analysis of epidemic keratoconjunctivitis caused by adenovirus type 54 in a regional ophthalmic clinic in Kyushu, Japan

Background

Human adenovirus type 54 (HAdV-54) is a novel type of adenovirus that belongs to species D and has thus far been detected only in Japan in patients with epidemic keratoconjunctivitis (EKC). There was a large nationwide outbreak of HAdV-54 EKC from 2015 to 2016 in Japan. The clinical characteristics of an outbreak of HAdV-54 conjunctivitis treated in a regional ophthalmic clinic in Fukuoka, Japan, in 2016 were analyzed.

Patients and methods

A consecutive series of 55 cases diagnosed clinically as EKC confirmed by HAdV-54 detection from conjunctival scrapings by polymerase chain reaction (PCR) method between 17 June 2016 and 29 August 2016 were enrolled. Viral DNA copies were counted by real-time PCR method. The clinical findings were recorded at the first visit to the clinic and evaluated.

Results

In the analysis of the relationship between mean clinical score groups and several factors, such as days after onset, sex, HAdV DNA number on a logarithmic scale, and age, most factors did not show a significant difference in clinical score between groups. However, mean clinical score of cases aged <23 years was significantly higher than that of cases aged ≥23 years (P<0.01). The correlation coefficient between DNA copies on a logarithmic scale and clinical score was 0.280, and a significant correlation was observed (P<0.05). Multiple subepithelial corneal infiltrates (MSI) were observed in 24 out of 31 cases (77%).

Conclusion

These results suggested that the clinical features in the early phase of HAdV-54 keratoconjunctivitis were milder but the rate of MSI observed in the late phase was higher than those in previous epidemics of several HAdV types. The significant difference in clinical severity between age groups might be a virological characteristic of HAdV-54.

Species differences in circulation and inflammatory responses in children with common respiratory adenovirus infections

Human adenoviruses (HAdVs) cause severe inflammatory respiratory infections, but previous epidemiological studies lacked analysis of the characteristics of the inflammation. Consecutive patients <13 years old with acute febrile illness during a 2‐year period were tested. HAdV strains were isolated from nasopharyngeal swabs, and molecular identification was performed by hexon, fiber, and species‐specific PCR methods. Blood inflammatory markers, including the white blood cell (WBC) count, CRP, and 29 cytokines, were measured. A total of 187 patients were enrolled, and HAdV types were identified from 175 patients (93.5%). Species C (types 2, 1, 5, and 6, in order of frequency) was most common at 37.1%, followed by B (type 3) at 30.9% and E (type 4) at 26.9%. Species C was detected predominantly in 1‐year‐old, whereas B and E were in older ages. Species C and B had seasonal circulation patterns, but E was found in only one season during the 2‐year study period. The WBC count was highest in patients with species C. Eleven of the 29 tested serum cytokines were detected. Seven kinds, including G‐CSF, IL‐6, and TNF‐α, were elevated in species C infections, whereas IL‐10 was lowest in species C. Species differences in inflammatory responses, especially regarding serum cytokines were described in common pediatric HAdV infections. Species C causes the strongest inflammatory responses in young children.

Clinical and molecular features of adenovirus type 2, 3, and 7 infections in children in an outbreak in Taiwan, 2011

Objectives

We studied paediatric patients with human adenovirus (HAdV) infection during the 2011 outbreak in northern Taiwan to define the clinical features of different HAdV genotypes in children.

Methods

Between January and December 2011, 637 patients <19 years of age exhibited culture-confirmed adenoviral infection in Chang Gung Memorial Hospital, and provided specimens available for genotyping by multiplex real-time PCR. Clinical data were collected retrospectively.

Results

Excluding five cases with multiple genotypes, 632 cases were included for analysis. Three genotypes were identified, including HAdV-3 (429/632; 67.6%), HAdV-7 (144/632; 22.6%) and HAdV-2 (59/632; 9.8%). Median age was 4.58 years (range 2 months to 18 years), with children infected with HAdV-3 significantly older (82.9% >3 years; p <0.001). Of the 621 inpatients, 98.2% had fevers and all exhibited respiratory symptoms, 75 patients (12.1%) had lower respiratory tract infections, 20 (3.2%) required intensive care (HAdV-2: 1; HAdV-3: 8; and HAdV-7: 11), and three died (all HAdV-7-infected). HAdV-3-infected patients were significantly more likely to have upper respiratory symptoms and a high serum C-reactive protein level >100 mg/L, whereas leucocytosis (white blood cell count >15 000/mm³) was more common in HAdV-2-infected patients (p 0.007). HAdV-7 infections were significantly associated with a longer duration of fever, leucopenia (white blood cell count <5000/mm³), thrombocytopenia (platelet count <150 000/mm³), lower respiratory tract infections, a longer length of hospital stay, and requiring intensive care (all p <0.001).

Conclusion

Childhood HAdV-2, HAdV-3 and HAdV-7 infections may exhibit different clinical manifestations. Although HAdV-3 was the most prevalent genotype observed during the 2011 Taiwan outbreak, HAdV-7 caused more severe disease characteristics and outcomes.

Whole-genome Sequencing for Tracing the Transmission Link between Two ARD Outbreaks Caused by a Novel HAdV Serotype 7 Variant, China

From December 2012 to February 2013, two outbreaks of acute respiratory disease caused by HAdV-7 were reported in China. We investigated possible transmission links between these two seemingly unrelated outbreaks by integration of epidemiological and whole-genome sequencing (WGS) data. WGS analyses showed that the HAdV-7 isolates from the two outbreaks were genetically indistinguishable; however, a 12 bp deletion in the virus-associated RNA gene distinguished the outbreak isolates from other HAdV-7 isolates. Outbreak HAdV-7 isolates demonstrated increased viral replication compared to non-outbreak associated HAdV-7 isolate. Epidemiological data supported that the first outbreak was caused by introduction of the novel HAdV-7 virus by an infected recruit upon arrival at the training base. Nosocomial transmission by close contacts was the most likely source leading to onset of the second HAdV-7 outbreak, establishing the apparent transmission link between the outbreaks. Our findings imply that in-hospital contact investigations should be encouraged to reduce or interrupt further spread of infectious agents when treating outbreak cases, and WGS can provide useful information guiding infection-control interventions.

Risk Factors for Severe Adenovirus Infection in Children during an Outbreak in Singapore

BACKGROUND

Human adenoviruses (HAdVs) can cause a variety of human illnesses, with associated temporal and geographic changes in disease incidence. We report the emergence of an outbreak of HAdV infections in Singapore, presumably caused by a change of the predominating type to HAdV-7. We examined the clinical features of children admitted with HAdV infection to 1 institution and the risk factors for severe infection.

MATERIALS AND METHODS

This is a retrospective case-control study of all HAdV-infected children admitted during weeks 1 to 19 in 2013, as identified from laboratory records. A descriptive retrospective analysis of epidemiology, clinical data and the outcome of these children was also performed. Patients with severe infections were defined as cases, those with non-severe infections as controls, and the 2 groups were compared to find possible independent risk factors.

RESULTS

Eighty-five patients with HAdV infection were studied, including 11 (12.9%) cases and 74 (87.1%) controls. Binary logistic regression showed that cases were more likely to be <2 years old (adjusted OR 10.6, 95% CI, 1.8 to 63.2) and to have significant comorbidities (adjusted OR 19.9, 95% CI, 3.4 to 116.1) compared to controls. The predominant type in 2013 was HAdV-7, which differed from 2011 and 2012, when HAdV-3 was more common. There was a trend towards pneumonia being more common in patients infected with HAdV-7 than in patients infected with other types, although this did not reach statistical significance (OR 2.8, 95% CI, 0.9 to 8.7).

CONCLUSION

The emergence of HAdV-7 in a population where other HAdV types had circulated previously may have caused the outbreak in Singapore, and this was associated with more serious infections in children. Young age (<2 years) and significant comorbidities were associated with more severe HAdV infection.

Re-emergent human adenovirus genome type 7d caused an acute respiratory disease outbreak in Southern China after a twenty-one year absence

Human adenoviruses (HAdVs) are highly contagious pathogens causing acute respiratory disease (ARD), among other illnesses. Of the ARD genotypes, HAdV-7 presents with more severe morbidity and higher mortality than the others. We report the isolation and identification of a genome type HAdV-7d (DG01_2011) from a recent outbreak in Southern China. Genome sequencing, phylogenetic analysis, and restriction endonuclease analysis (REA) comparisons with past pathogens indicate HAdV-7d has re-emerged in Southern China after an absence of twenty-one years. Recombination analysis reveals this genome differs from the 1950s-era prototype and vaccine strains by a lateral gene transfer, substituting the coding region for the L1 52/55 kDa DNA packaging protein from HAdV-16. DG01_2011 descends from both a strain circulating in Southwestern China (2010) and a strain from Shaanxi causing a fatality and outbreak (Northwestern China; 2009). Due to the higher morbidity and mortality rates associated with HAdV-7, the surveillance, identification, and characterization of these strains in population-dense China by REA and/or whole genome sequencing are strongly indicated. With these accurate identifications of specific HAdV types and an epidemiological database of regional HAdV pathogens, along with the HAdV genome stability noted across time and space, the development, availability, and deployment of appropriate vaccines are needed.

Diagnosis and treatment of adenovirus infection in immunocompromised patients

In immunocompromised patients, human adenovirus (HAdV) infections can cause life-threatening multiorgan disease. This review summarizes the incidence and risk factors of invasive human adenovirus infections in immunocompromised patients as well as the recently developed standards for diagnostic methods and strategies according to the predominant risk factors in adults and children. Recommendations for preemptive and therapeutic treatment strategies and the outcome in different risk groups are presented. Novel therapeutic approaches including CMX001, a new orally bioavailable lipid conjugate of cidofovir and the transfer of adenovirus-specific donor T cells in the context of allogeneic stem cell transplantation are discussed.

Community outbreak of adenovirus, Taiwan, 2011

Adenovirus type 7 caused a high proportion of severe infections.

In 2011, a large community outbreak of human adenovirus (HAdV) in Taiwan was detected by a nationwide surveillance system. The epidemic lasted from week 11 through week 41 of 2011 (March 14–October 16, 2011). Although HAdV-3 was the predominant strain detected (74%), an abrupt increase in the percentage of infections caused by HAdV-7 occurred, from 0.3% in 2008–2010 to 10% in 2011. Clinical information was collected for 202 inpatients infected with HAdV; 31 (15.2%) had severe infection that required intensive care, and 7 of those patients died. HAdV-7 accounted for 10%, 12%, and 41% of infections among outpatients, inpatients with nonsevere infection, and inpatients with severe infection, respectively (p<0.01). The HAdV-7 strain detected in this outbreak is identical to a strain recently reported in the People’s Republic of China (HAdV7-HZ/SHX/CHN/2009). Absence of circulating HAdV-7 in previous years and introduction of an emerging strain are 2 factors that caused this outbreak.

Adenovirus serotype 3 and 7 infection with acute respiratory failure in children in Taiwan, 2010-2011

Objective

Increased incidence of adenovirus infection in children was noticed since September 2010 in Taiwan and severe cases requiring intensive care were noted later. We did this study to find the clinical characteristics and risk factors associated with severe adenovirus infection.

Patients and Methods

We collected cases of severe adenovirus infection between November 2010 and June 2011 to analyze their clinical characteristics in two medical centers in northern Taiwan. Severe adenovirus infection was defined as laboratory-confirmed adenovirus cases with required intensive care. Hexon gene sequencing was performed for molecular genotyping.

Results

45 patients were included, 22 cases (49%) were infected with serotype 7, 19 (42%) with serotype 3, and 4 with serotype 2. The median age (range) was 2.75 years (0.08–15.43 years); 87% were below 5 years. Male to female ratio was 1.65 (28 to 17). Of these patients, 56% had underlying neurological diseases, 50% experienced fever higher than 40°C and 69% suffered fever longer than one week. The clinical diagnosis included pneumonia in 40 (89%) patients, bronchopneumonia in 5 (11%), and encephalitis in 7 (16%). At least 22 patients had pleural effusion. They had complications of respiratory failure (53%), acute respiratory distress syndrome (24%), hypotension (40%), and 6 (13%) patients needed extracorporeal membranous oxygenation. Ten (22%) patients died, all with underlying major systemic diseases and 7 (70%) infected with serotype 7.

Conclusions

Adenovirus serotype 7 and 3 can cause severe disease–even death–in children, especially those with underlying neurological diseases. Patients infected with adenovirus serotype 7 tended to have a higher case-fatality rate.

Temporal changes in respiratory adenovirus serotypes circulating in the greater Toronto area, Ontario, during December 2008 to April 2010

Background

Certain adenovirus serotypes cause severe infections, especially in children. It is important to monitor temporal changes in serotypes causing clinical disease. The objective of this study was to document circulating respiratory adenovirus serotypes by sequencing adenovirus culture isolates from the Greater Toronto Area, Ontario, during December 2008 to April 2010.

Methods

Nucleic acid extraction was performed on 90 respiratory tract adenovirus culture isolates. PCR amplification was conducted with primers targeting the adenovirus hexon gene hypervariable region 7. Sanger sequencing and phylogenetic analyses were performed to determine serotype identities.

Results

Among 90 clinical respiratory isolates sequenced, eight different serotypes were identified. Serotype 3 (34, 38%), serotype 2 (30, 30%), and serotype 1 (14, 16%) isolates were most common; serotypes 5, 6, 11, 17 and 21 were also observed. Seventeen (50%) of the 34 HAdV-3 isolates were identified between December 2008 and February 2009, while none were identified from December 2009 to February 2010. Between December 2008 and April 2009, the two most common serotypes were HAdV-3 and HAdV-2, detected in 18 (53%) and 8 (24%) of the 34 cultures isolates, respectively. However, from December 2009 to April 2010, there was an increase in HAdV-2, which became the most prevalent serotype, detected in 10 (50%) of the 20 isolates identified (p = 0.05).

Conclusions

There was a gradual shift in prevailing adenovirus serotypes during the 17 month study period, from predominantly HAdV-3 to HAdV-2. If an adenovirus vaccine were to be broadly implemented, multiple serotypes should be included.

A molecular epidemiology survey of respiratory adenoviruses circulating in children residing in Southern Palestine

A molecular epidemiology survey was performed in order to establish and document the respiratory adenovirus pathogen profiles among children in Southern Palestine. Three hundred and thirty-eight hospitalized pediatric cases with adenovirus-associated respiratory tract infections were analyzed. Forty four cases out of the 338 were evaluated in more detail for the adenoviruses types present. All of the children resided in Southern Palestine, that is, in city, village and refugee camp environments within the districts of Hebron and Bethlehem. Human adenoviruses circulated throughout 2005–2010, with major outbreaks occurring in the spring months. A larger percent of the children diagnosed with adenoviral infections were male infants. DNA sequence analysis of the hexon genes from 44 samples revealed that several distinct adenovirus types circulated in the region; these were HAdV-C1, HAdV-C2, HAdV-B3 and HAdV-C5. However, not all of these types were detected within each year. This is the first study ever conducted in Palestine of the genetic epidemiology of respiratory adenovirus infections.

Epidemiology of human metapneumovirus in a pediatric long-term care facility

BACKGROUND

Viral respiratory pathogens cause outbreaks in pediatric long-term care facilities (LTCFs), but few studies have used viral diagnostic testing to identify the causative pathogens. We describe the use of such testing during a prolonged period of respiratory illness and elucidate the epidemiology of human metapneumovirus (hMPV) at our LTCF.

DESIGN

Retrospective study of influenza-like illness (ILI).

SETTING

A 136-bed pediatric LTCF from January 1 through April 30, 2010.

METHODS

The ILI case definition included fever, cough, change in oropharyngeal secretions, increase in oxygen requirement, and/or wheezing.

RESULTS

During the study period, 69 episodes of ILI occurred in 61 (41%) of 150 residents. A viral pathogen was detected in 27 (39%) of the episodes, including respiratory syncytial virus (RSV) (n = 3), influenza A virus (not typed; n = 2), parainfluenza virus (n =2), adenovirus (n = 1), and hMPV (n = 19). Twenty-seven of the residents with ILI (44%) required transfer to acute care hospitals (mean length of hospitalization, 12 days; range, 3-47 days). Residents with tracheostomies were more likely to have ILI (adjusted odds ratio [OR], 3.99 [95% confidence interval {CI}, 1.87-8.53]; P = .0004). The mortality rate for residents with ILI was 1.6%. Residents with hMPV were younger (P = .03), more likely to be transferred to an acute care facility (OR, 3.73 [95% CI, 1.17-11.95]; P = .02), and less likely to have a tracheostomy (adjusted OR, 0.19 [95% CI, 0.047-0.757]; P = .02 ).

DISCUSSION

Diverse pathogens, most notably hMPV, caused ILI in our pediatric LTCF during a prolonged period of time. Viral testing was helpful in characterizing the epidemiology of ILI in this population.

Epidemiology of severe pediatric adenovirus lower respiratory tract infections in Manitoba, Canada, 1991-2005

Background

Most pediatric adenovirus respiratory infections are mild and indistinguishable from other viral causes. However, in a few children, the disease can be severe and result in substantial morbidity. We describe the epidemiologic, clinical, radiologic features and outcome of adenovirus lower respiratory tract infections (LRTI) in Aboriginal and Non-Aboriginal children in Manitoba, Canada during the years 1991 and 2005.

Methods

This was a retrospective study of 193 children who presented to the department of pediatrics at Winnipeg Children's Hospital, Manitoba, Canada with LRTI and had a positive respiratory culture for adenovirus. Patients' demographics, clinical and radiologic features and outcomes were collected. Adenovirus serotype distributions and temporal associations were described. Approximate incidence comparisons (detection rates) of adenovirus LRTI among Aboriginal and Non-Aboriginal children were estimated with 95% confidence intervals.

Results

Adenovirus infections occurred throughout the year with clusters in the fall and winter. Serotypes 1 to 3 were the predominant isolates (two thirds of the cases). The infection was more frequent among Canadian Aboriginals, as illustrated in 2004, where its incidence in children 0-4 years old was 5.6 fold higher in Aboriginals (13.51 vs. 2.39 per 10,000, p < 0.000). There were no significant differences in length of hospitalization and use of ventilator assistance between the two groups (p > 0.185 and p > 0.624, respectively) nor across serotypes (p > 0.10 and p > 0.05, respectively). The disease primarily affected infants (median age, 9.5 months). Most children presented with bronchiolitis or pneumonia, with multi-lobar consolidations on the chest x-ray. Chronic (residual) changes were documented in 16 patients, with eight patients showing bronchiectasis on the chest computerized tomography scan.

Conclusions

Adenovirus infection is associated with significant respiratory morbidities, especially in young infants. The infection appears to be more frequent in Aboriginal children. These results justify a careful follow-up for children with adenovirus LRTI.