Incidence of acute otitis media associated with group A and B respiratory syncytial virus infections

Relating plaque morphology to respiratory syncytial virus subgroup, viral load, and disease severity in children

BACKGROUND

Viral culture plaque morphology in human cell lines are markers for growth capability and cytopathic effect, and have been used to assess viral fitness and select preattenuation candidates for live viral vaccines. We classified respiratory syncytial virus (RSV) plaque morphology and analyzed the relationship between plaque morphology as compared to subgroup, viral load and clinical severity of infection in infants and children.

METHODS

We obtained respiratory secretions from 149 RSV-infected children. Plaque morphology and viral load was assessed within the first culture passage in HEp-2 cells. Viral load was measured by polymerase chain reaction (PCR), as was RSV subgroup. Disease severity was determined by hospitalization, length of stay, intensive care requirement, and respiratory failure.

RESULTS

Plaque morphology varied between individual subjects; however, similar results were observed among viruses collected from upper and lower respiratory tracts of the same subject. Significant differences in plaque morphology were observed between RSV subgroups. No correlations were found among plaque morphology and viral load. Plaque morphology did not correlate with disease severity.

CONCLUSION

Plaque morphology measures parameters that are viral-specific and independent of the human host. Morphologies vary between patients and are related to RSV subgroup. In HEp-2 cells, RSV plaque morphology appears unrelated to disease severity in RSV-infected children.

Epidemiological changes of respiratory syncytial virus (RSV) infections in Israel

RSV is the leading cause of lower respiratory-tract infections in infants and therefore demands in-depth epidemiological characterization. We investigated here the distribution of RSV types in Israel between the years 2005–2012. Clinical samples were collected from 11,018 patients hospitalized due to respiratory illnesses and were evaluated for the presence of various respiratory viruses, including RSV A and RSV B. Until 2008, each year was characterized by the presence of one dominant type of RSV. However, from 2008, both RSV A and B types were detected at significant levels, particularly among infants aged 0–2 years. Furthermore, significant changes in the RSV A and RSV B subtypes circulating in Israel since 2008 were observed. Finally, we demonstrate that, irrespectively of the changes observed in RSV epidemiology, when the pandemic H1N1pdm09 influenza virus appeared in 2009, RSV infections were delayed and were detected when infection with H1N1pdm09 had declined.

Antimicrobial susceptibility pattern of clinical isolates from cases of ear infection using amoxicillin and cefepime

The aim of the present study was to determine the sensitivity pattern of clinical isolates of otitis media. During the last few decades, the occurrence of otitis media seems to have been rising probably because of prevalence of multidrug-resistant Pseudomonas aeruginosa and β-lactamase producing Staphylococcus aureus in the pathogenesis of otitis media. Pseudomonas aeruginosa and Staphylococcus aureus were the most common causative microorganisms of ear infection. Keeping in view the importance of these pathogens, the present study had been designed to determine the sensitivity pattern of clinical isolates of otitis media. These isolates were collected from different hospitals and pathological laboratories of Karachi and their sensitivity against cefepime and amoxicillin were determined by using disk diffusion method. The results have shown that Pseudomonas aeruginosa was the most common causative microorganism of ear infection. Cefepime, a fourth generation cephalosporin appeared to be an effective antibiotic against Pseudomonas aeruginosa and Staphylococcus aureus.

Molecular epidemiology and disease severity of human respiratory syncytial virus in Vietnam

Respiratory syncytial virus (RSV) is a major cause of acute respiratory infections (ARIs) in children worldwide and can cause high mortality, especially in developing countries. However, information on the clinical and molecular characteristics of RSV infection in developing countries is limited. From April 2010 to May 2011, 1,082 nasopharyngeal swabs were collected from children with ARI admitted to the Children's Hospital 2, Ho Chi Minh City, Vietnam. Samples were screened for RSV and genotyped by reverse transcription-PCR and sequencing. Demographic and clinical data was also recorded. RSV was found in 23.8% (257/1,082) of samples. RSV A was the dominant subgroup, accounting for 91.4% (235/257), followed by RSV B, 5.1% (13/257), and 9 cases (3.5%) were mixed infection of these subgroups. The phylogenetic analysis revealed that all group A strains belonged to the GA2 genotype. All group B strains belonged to the recently identified BA genotype, and further clustered into 2 recently described subgenotypes BA9 and BA10. One GA2 genotype strain had a premature stop codon which shortened the G protein length. RSV infection was significantly associated with younger age and higher severity score than those without. Co-infection with other viruses did not affect disease severity. RSV A caused more severe disease than RSV B. The results from this study will not only contribute to the growing database on the molecular diversity of RSV circulating worldwide but may be also useful in clinical management and vaccine development.

Risk of acute otitis media in relation to acute bronchiolitis in children

OBJECTIVE

A prospective study was carried out to evaluate the prevalence and the etiology of acute otitis media (AOM) in children with acute bronchiolitis. Also to determine whether AOM occurring with acute bronchiolitis is accompanied with another pathogens or not.

SUBJECTS AND METHODS

One hundred and eighty children with acute bronchiolitis aged 3-18 months who were admitted to pediatrics department, Minia University hospital, were included in the study done in the winter and spring of 2009. In patients with AOM at entry or developed AOM within 14 days, Gram-stained smears, bacterial cultures, and enzyme-linked immunosorbent assay (ELISA) were performed on middle-ear aspirates to detect the presence of bacterial pathogens and RSV respectively.

RESULTS

One hundred children (55.6%) with acute bronchiolitis had AOM at entry or developed AOM within 14 days, 45 patients (25%) had developed otitis media with effusion, and only 35 patients (19.4%) remained free throughout the 2-week observation period. Of 135 middle-ear aspirates (65 unilateral and 35 bilateral), bacterial pathogens were isolated in 86 patients (86%) [37 bacteria alone "37%" and 49 mixed bacteria and RSV "49%"], RSV was identified in 56 patients (56%) of middle ear aspirates [mixed with bacteria in 49 patients and RSV alone in 7 cases (7%).

CONCLUSION

We concluded that bacterial AOM is a complication in most children with acute bronchiolitis. Streptococcus pneumonia and Haemophilus influenza were the commonest organisms isolated from middle ear aspirate. RSV is identified in 56% of acute otitis media with bronchiolitis.

Temporal relationships for cold-like illnesses and otitis media in sibling pairs

BACKGROUND

New otitis media (OM) episodes are most frequently a complication of cold-like illnesses (CLIs) which are often virus infections that can be exchanged within the family unit. Interference with intrafamily CLI transmission may present a strategy for OM prophylaxis in high risk children. This study estimated factors relevant to strategy efficiency.

METHODS

Two siblings (ages, 1.0-4.3 and 1.7-6.1 years) from 69 families were followed for 193 days beginning in October using daily parental diaries focused on CLI signs and weekly pneumatic otoscopy to diagnose OM presence/absence. An algorithm converted the signs to presence/absence of a cold-day; cold-days were grouped into CLI episodes, and episodes were examined for intersib transmission and OM complications.

RESULTS

We identified 267 CLIs in the younger siblings and 221 in the older siblings. Twenty-seven percent of the CLI episodes in one sibling occurred after CLI onset in the other with a median interval of 3 days. Sixty-two percent of newly diagnosed OM episodes occurred during a CLI and 27% of CLIs were complicated by OM. Analysis of factors that could affect CLI incidence documented significant contributions of gender, age, daily environment and the CLI burden in the sibling with expected directionalities.

CONCLUSION

The results document intrafamily transmission of CLIs that is often associated with the development of OM as a complication. These observations and the measured interval between primary and secondary CLI onsets support the possibility of preventing OM by strategies that target intrafamily CLI transmission.

Temporal relationships between colds, upper respiratory viruses detected by polymerase chain reaction, and otitis media in young children followed through a typical cold season

INTRODUCTION

Otitis media is a frequent complication of a viral upper respiratory tract infection, and the reported co-incidence of those diseases increases with assay sensitivity and sampling density. We determined the incidence of otitis-media complications in young children when referenced to cold-like illnesses and to concurrent virus recovery from the nasopharynx.

METHODS

A total of 60 children from 24 families were followed from October 2003 through April 30, 2004, by daily parental recording of illness signs, weekly pneumatic otoscopic examinations, and periodic polymerase chain reaction assay of collected nasal fluids for common viruses.

RESULTS

One hundred ninety-nine cold-like illnesses were observed, but a sample for virus assay was not collected concurrent with 71 episodes. Of the remainder, 73% of cold-like illnesses were temporally related to recovery of 1 or a combination of the assayed viruses, with rhinovirus predominating. For non-cold-like illness periods, 54 (18%) of 297 assays were positive for virus, and the virus frequency distribution was similar to that for cold-like illnesses. There were 93 diagnosed otitis-media episodes; 65 (70%) of these occurred during a cold-like illness. For the 79 otitis-media episodes with available nasal samples, 61 (77%) were associated with a positive virus result. In this population, the otitis-media complication rate for a cold-like illness was 33%.

CONCLUSIONS

A cold-like illness was not a prerequisite for polymerase chain reaction detection of viruses in the nose and nasopharynx of young children. Viral detection by polymerase chain reaction in the absence of a cold-like illness is associated with complications in some subjects. Otitis media is a complication of viral infection both with and without concurrent cold-like illnesses, thus downwardly biasing coincidence estimates that use cold-based illnesses as the denominator.

A high prevalence of new onset otitis media during parent diagnosed common colds

INTRODUCTION

Past studies suggest that the majority of new otitis media (OM) diagnoses is a complication of a colds/flu. A prospective format was used to determine the coincidence of otitis media and parent diagnosed cold/flu episodes in young children followed over a typical cold/flu season.

METHODS

Eighteen families with children aged 1-8 years were followed from October 1 to April 30 using parent-completed daily diaries focused on cold/flu signs and weekly examinations using pneumatic otoscopy for diagnosis of the presence/absence of otitis media.

RESULTS

Overall, 108 cold episodes were documented in 36 enrolled children with 20 colds (19%) occurring during a pre-existing OM episode and 40 colds (37%) complicated by a new OM episode. Conversely, there were 82 new OM episodes, 40 (49%) were associated with a cold in the individual child and 18 (22%) with a concurrent cold in a family member. The median duration of the OM episodes was approximately 2 weeks but this was longer for OM episodes where earache was reported.

CONCLUSION

The results confirm past observation relating new OM episodes to a concurrent cold/flu but show these episodes to usually be of short duration. Two sources of potential bias were identified for point prevalence study formats: the presence of a pre-existing OM for a new onset cold/flu and the possibility of subclinical colds in patients with new OM episodes. These biases reinforce the need for longitudinal study formats to address this important relationship.

G protein variation in respiratory syncytial virus group A does not correlate with clinical severity

Respiratory syncytial virus group A strain variations of 28 isolates from The Netherlands collected during three consecutive seasons were studied by analyzing G protein sequences. Several lineages circulated repeatedly and simultaneously during the respective seasons. No relationships were found between lineages on the one hand and clinical severity or age on the other.

Nosocomial respiratory syncytial virus infections in children's wards

During community outbreak, nosocomial infections caused by both groups (A and B) of respiratory syncytial virus (RSV) occur as the most common nosocomial infections at pediatric wards. RSV cross-infection is considered to have taken place when a child acquires an infection after being in the ward longer than 7 days, and its frequency at the ward could be calculated in several ways. That frequency ranges worldwide between 30% and 70% in neonatal units, and between 20% and 40% at pediatric wards. The infections are manifested as lower respiratory tract infections (LRTI) in 20-60% and 30-40% of cases, respectively. These infections could be early diagnosed by an RSV rapid detection method. In RSV-positive children who develop LRTI and belong to the category with a high risk of developing severe RSV disease, a specific therapy is recommended. The frequency of RSV nosocomial infections at children's wards could be considerably reduced (to only a few per cent) by providing education to hospital personnel in the etiology and transmission of respiratory viruses and by compliance with pediatric droplet precautions (cohort nursing, and gown and glove wearing/handwashing in any contact with infected children).

Prevalence of various respiratory viruses in the middle ear during acute otitis media

BACKGROUND

Vaccines against respiratory viruses may be able to reduce the frequency of acute otitis media. Although the role of respiratory viruses in the pathogenesis of acute otitis media is well established, the relative importance of various viruses is unknown.

METHODS

We determined the prevalence of various respiratory viruses in the middle-ear fluid in 456 children (age, two months to seven years) with acute otitis media. At enrollment and after two to five days of antibiotic therapy, specimens of middle-ear fluid and nasal-wash specimens were obtained for viral and bacterial cultures and the detection of viral antigens. The viral cause of the infections was also assessed by serologic studies of serum samples obtained during the acute illness and convalescence.

RESULTS

A specific viral cause of the respiratory tract infections was identified in 186 of the 456 children (41 percent). Respiratory syncytial virus was the most common virus identified in middle-ear fluid: it was detected in the middle-ear fluid of 48 of the 65 children (74 percent) infected by this virus (P< or =0.04 for the comparison with any other virus). Parainfluenza viruses (15 of 29 children [52 percent]) and influenzaviruses (10 of 24 children [42 percent]) were detected in the middle-ear fluid significantly more often than enteroviruses (3 of 27 children [11 percent]) or adenoviruses (1 of 23 children [4 percent]) (P< or =0.01 for all comparisons).

CONCLUSION

Respiratory syncytial virus is the principal virus invading the middle ear during acute otitis media. An effective vaccine against upper respiratory tract infections caused by respiratory syncytial virus may reduce the incidence of acute otitis media in children.

Acute otitis media in children with bronchiolitis

OBJECTIVE

We investigated the prevalence and the etiology of acute otitis media (AOM) in children with bronchiolitis to determine whether AOM in such children is due entirely or mainly to respiratory syncytial virus (RSV), in which case routine antimicrobial treatment would not be appropriate.

METHODS

The study group consisted of children aged 2 to 24 months with bronchiolitis. In patients with AOM at entry, nasal washings for RSV enzyme-linked immunosorbent assay were obtained, and Gram-stained smear, bacterial culture, and reverse transcriptase polymerase chain reaction to detect the presence of RSV were performed on middle-ear aspirates. Patients without AOM were reevaluated at 48 to 72 hours, 8 to 10 days, and 18 to 22 days.

RESULTS

Forty-two children with bronchiolitis were enrolled. Sixty-two percent had AOM at entry or developed AOM within 10 days. An additional 24% had or eventually developed otitis media with effusion. Only 14% remained free of both AOM and otitis media with effusion throughout the 3-week observation period. All patients with AOM had 1 or more bacterial pathogens isolated from one or both middle-ear aspirates. Of 33 middle-ear aspirates, Streptococcus pneumoniae was isolated in 15, Haemophilus influenzae in 8, Moraxella catarrhalis in 8, and Staphylococcus aureus in 2. Two middle-ear aspirates yielded 2 pathogens each; 2 aspirates had no growth. RSV was identified in 17 (71%) of 24 patients with AOM.

CONCLUSION

Bacterial AOM is a complication in most children with bronchiolitis. Accordingly, in patients with bronchiolitis and associated AOM, antimicrobial treatment is indicated.

Role of viruses in middle-ear disease

Taken together, there is ample evidence suggesting a role for viruses in the pathogenesis of OM. This evidence comes from numerous studies performed in animals and in vitro cell cultures, as well as in adults and children with URI and OM. Viruses induce host immune and inflammatory responses that result in pathology of the ET and the middle ear, and predispose the host in various ways to secondary bacterial infection. A suggested mechanism for the pathogenesis of OM following respiratory viral infection is presented in Figure 1.