Signs Of Respiratory Infection Research Articles

Evaluation of commercial ResPlex II v2.0, MultiCode ®-PLx, and xTAG ® respiratory viral panels for the diagnosis of respiratory viral infections in adults

Background Commercial multiplex PCR panels for respiratory viruses (PRV) have been recently developed. ResPlex II Panel v2.0 (Qiagen), MultiCode ®-PLx (EraGen Biosciences), and xTAG ® (Luminex) PRV's were studied. All assays detect influenza A and B, adenovirus, parainfluenza 1–3, respiratory syncytial virus A and B, human metapneumovirus and human rhinovirus. The ResPlex II additionally detects coronavirus (229E, OC43, NL63, HKU1), coxsackie/echo virus, bocavirus and differentiates adenoviruses (B, E). The MultiCode-PLX assay detects 229E, OC43, and NL63, differentiates parainfluenza 4a, 4b and adenoviruses (B, C, E). The xTAG additionally subtypes influenza A as seasonal H1 and H3. Study design 202 specimens collected from adult patients with signs of respiratory infection from November, 2008 to May, 2009 were used for evaluating the performance of the three commercial PRV assays. Viral culture and xTAG were used as the standards to assess sensitivity and specificity. Results The PRV assays detected more viruses than culture. When compared to culture, the xTAG PRV showed a sensitivity and specificity of 100% and 91%, compared to MultiCode-PLx with 89% and 87%, and ResPlex II with 89% and 94%, respectively. Co-infection was detected in a small subset of patient specimens. Each panel showed differences in sensitivities for individual viruses. Conclusions While the ResPlex II and MultiCode-PLx offer a broader virus detection range and greater ease of use, the xTAG PRV showed increased sensitivity to common viral targets represented in the assays, and also had the ability to differentiate human from non-human influenza A H1.

Mycoplasma ovipneumoniae can predispose bighorn sheep to fatal Mannheimia haemolytica pneumonia

Mycoplasma ovipneumoniae has been isolated from the lungs of pneumonic bighorn sheep (BHS). However experimental reproduction of fatal pneumonia in BHS with M. ovipneumoniae was not successful. Therefore the specific role, if any, of M. ovipneumoniae in BHS pneumonia is unclear. The objective of this study was to determine whether M. ovipneumoniae alone causes fatal pneumonia in BHS, or predisposes them to infection by Mannheimia haemolytica. We chose M. haemolytica for this study because of its isolation from pneumonic BHS, and its consistent ability to cause fatal pneumonia under experimental conditions. Since in vitro culture could attenuate virulence of M. ovipneumoniae, we used ceftiofur-treated lung homogenates from pneumonic BHS lambs or nasopharyngeal washings from M. ovipneumoniae-positive domestic sheep (DS) as the source of M. ovipneumoniae. Two adult BHS were inoculated intranasally with lung homogenates while two others received nasopharyngeal washings from DS. All BHS developed clinical signs of respiratory infection, but only one BHS died. The dead BHS had carried leukotoxin-positive M. haemolytica in the nasopharynx before the onset of this study. It is likely that M. ovipneumoniae colonization predisposed this BHS to fatal infection with the M. haemolytica already present in this animal. The remaining three BHS developed pneumonia and died 1–5 days following intranasal inoculation with M. haemolytica. On necropsy, lungs of all four BHS showed lesions characteristic of bronchopneumonia. M. haemolytica and M. ovipneumoniae were isolated from the lungs. These results suggest that M. ovipneumoniae alone may not cause fatal pneumonia in BHS, but can predispose them to fatal pneumonia due to M. haemolytica infection.

Unilateral Pulmonary Artery Agenesis

A 46-year-old female patient presented at the emergency department with hemoptysis of unknown cause. Past medical history was significant for pulmonary hypertension with Eisenmenger syndrome due to a patent ductus arteriosus that had been diagnosed in childhood. Additionally, mild asthma was reported. Except for mild dyspnea and coughing, the patient was in good general condition and did not show any signs of respiratory infection. Abdominal hysterectomy had been performed due to a uterine myoma 1 year before. Physical examination showed differential central cyanosis with clubbing of the toes but not of the fingers. Cardiac auscultation revealed an accentuated second heart sound at the base and a 2/6 continuous machinery murmur at the upper left sternal region. On lung auscultation, left-sided basilar rales were noted, but no wheezing. Pertinent laboratory results were unremarkable except for microcytic, hypochromic polycythemia (red blood cells: 7.96×106/μL, mean corpuscular volume 74.7 fL, mean corpuscular hemoglobin 23.6 pg/cell). Blood oxygen …

Mycoplasma pneumoniae–Associated Transverse Myelitis and Rhabdomyolysis

Mycoplasma pneumoniae is a common cause of respiratory tract infection. Extrapulmonary manifestations of M. pneumoniae infection are also common. The present case is that of a previously healthy 4-year-old boy who displayed a novel simultaneous onset of both acute rhabdomyolysis and transverse myelitis associated with an infection of M. pneumoniae. He had no preceding symptoms or signs of respiratory tract infection. Intravenous immunoglobulin (1 g/kg per day) for 2 days was prescribed initially for the deterioration of neurologic condition. His rhabdomyolysis resolved without complication, but neurologic sequelae remained during 2 years of follow-up. Evaluation for M. pneumoniae infection is recommended in patients with idiopathic rhabdomyolysis and transverse myelitis, even if in the absence of antecedent respiratory symptoms.

Detection of nasopharyngeal carriages in children by multiplex reverse transcriptase-polymerase chain reaction

Purpose : The aim of this study was to determine the prevalence of asymptomatic nasopharyngeal carriages in children using a multiplex reverse transcriptase-polymerase chain reaction (mRT-PCR) assay kit. Methods : We obtained nasopharyngeal swabs from 33 children without any underlying disease from July 25 to July 28, 2008. The children were free from the signs of respiratory tract infections at the time of sampling. DNA was extracted from the swabs and subjected to multiplex RT-PCR using a primer set for the detection of pneumococci (Seeplex ® PneumoBacter ACE Detection Seegene, Seoul, Korea). The amplified PCR products were separated on 2% agarose gels and stained with either ethidium bromide or screen tape system (Lab901 Scotland, UK). Results : A total of 33 children (male, 15 female, 18) aged between 3.2 and 16.3 (median, 8.2) years were included in this study. The mRT-PCR detected colonized bacteria (Streptococcus pneumoniae, Hemophilus influenzae, Chlamydia pneumoniae, and Bordetella pertussis) in 30 children (90.9%). Of these, 13 children (39.4%) showed more than 2 bacteria: 12 children were positive for 2 bacteria (S. pneumoniae and H. influenzae) and 1 child was positive for 3 bacteria (S. pneumoniae, H. influenzae, and C. pneumoniae). Conclusion : mRT-PCR was found to be a sensitive tool for the detection of asymptomatic nasopharyngeal carriages. Clinical significances of the bacteria detected by mRT-PCR will have to be evaluated in the future. (Korean J Pediatr 2009; 52:1358-1363)

The Clinical Significance of Nasopharyngeal Carriages in Immunocompromised Children as Assessed

Background: The aim of this study was to determine the prevalence of asymptomatic nasopharyngeal carriages in immunocompromized children by using a multiplex reverse transcriptase-polymerase chain reaction (mRT-PCR) assay kit. Methods: We obtained clinical samples by nasopharyngeal swabs from 42 patients with underlying immune deficiency from May 20, 2008 to May 22, 2008. The children were free from signs of respiratory tract infections at the time of sampling. Isolated cDNA was extracted and after this the DNA was examined using a multiplex primer set for pneumonial bacteria detection (SeeplexR PneumoBacter ACE Detection, Seegene, Seoul, Korea). The amplified PCR products were separated on 2% agarose gels and stained with ethidium bromide and a screentape system (Lab901, Scottland, UK) and then they were compared. The nasopharyngeal swab culture was done simultaneously and this was compared with the results of mRT-PCR. Results: A total of 42 patients (males: 24, females: 18) aged between 1.2 and 16.3 years (median: 9.2 years) were included in this study. The mRT-PCR detected bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Chlamydia pneumoniae, and Bordetella pertussis) in 28 patients (66.6%). Of these 28 patients, 4 patients (14.3%) showed more than 2 bacteria: 2 patients were positive for two bacteria (S. pneumoniae and H. influenzae, H.influenzae and B. pertussis) and 2 patients were positive for three bacteria (S. pneumoniae, B. pertussis and C. pneumoniae, C. Pneumoniae, H. influenzae and B. pertussis). S. pneumoniae was cultured in one patient (2.4%). Conclusions: The mRT-PCR is a sensitive tool for the detection of the asymptomatic nasopharyngeal carriages. The clinical significance of the bacteria detected in immunocompromized patients by mRT-PCR will need further evaluation. (Korean J Hematol 2009;44:220-226) 󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏

Aerosolized antibiotics and ventilator-associated tracheobronchitis in the intensive care unit*

In critically ill intubated patients, signs of respiratory infection often persist despite treatment with potent systemic antibiotics. The purpose of this study was to determine whether aerosolized antibiotics, which achieve high drug concentrations in the target organ, would more effectively treat respiratory infection and decrease the need for systemic antibiotics. Double-blind, randomized, placebo-controlled study performed from 2003 through 2004. The medical and surgical intensive care units of a university hospital. Critically ill intubated patients were randomized if: 1) > or = 18 yrs of age, intubated for a minimum of 3 days, and expected to survive at least 14 days; and 2) had ventilator-associated tracheobronchitis defined as the production of purulent secretions (> or = 2 mL during 4 hrs) with organism(s) on Gram stain. Of 104 patients monitored, 43 consented for treatment and completed the study. No patients were withdrawn from the study for adverse events. Aerosol antibiotic (AA) or aerosol saline placebo was given for 14 days or until extubation. The responsible clinician determined the administration of systemic antibiotics (SA). Patients were followed for 28 days. Primary: Centers for Disease Control National Nosocomial Infection Survey diagnostic criteria for ventilator-associated pneumonia (VAP) and clinical pulmonary infection score. Secondary: white blood cell count, SA use, acquired antibiotic resistance, and weaning from mechanical ventilation. Most patients had VAP at randomization. With treatment, the AA group had reduced signs of respiratory infection: reduced Centers for Disease Control National Nosocomial Infection Survey VAP (14/19; 73.6%) to (5/14; 35.7%) vs. placebo (18/24; 75%) to (11/14; 78.6%), reduction in clinical pulmonary infection score, lower white blood cell count at day 14, reduced bacterial resistance, reduced use of SA, and increased weaning (all p < or = .05). In critically ill patients with ventilator-associated tracheobronchitis, AA decrease VAP and other signs and symptoms of respiratory infection, facilitate weaning, and reduce bacterial resistance and use of systemic antibiotics.

Human Metapneumovirus Infections in Children

Human metapneumovirus (hMPV) is an important cause of lower respiratory tract infections in hospitalized children, but the age-related incidence and effect of hMPV in unselected children in the community have not been evaluated. We studied a cohort of 1,338 children <13 years of age throughout 1 respiratory season in Finland during 2000-2001. We examined children and obtained a nasal swab for viral detection at any sign of respiratory infection. hMPV was detected in 47 (3.5%) of the 1,338 children. The age-related incidence of hMPV infection was highest (7.6%) in children <2 years of age, in whom hMPV accounted for 1.7% of all infections during the season. During the epidemic peak, hMPV caused 7.1% of all respiratory infections in the cohort. Acute otitis media developed in 61% of hMPV-infected children <3 years of age. Our findings demonstrate that the effect of hMPV in the community is greatest in children <2 years of age.

Etiologic Study on Upper Respiratory Infections of Household Dogs

Infectious tracheobronchitis (ITB), also known as the kennel cough, is a respiratory syndrome of dogs and usually appears to be contagious among dogs housed in groups. Etiologic agent of ITB is multiple and sometimes complex. In the present study, 68 household dogs showing clinical signs of respiratory infection were examined, and 20 dogs (29.4%) were found to be positive for either of following agents. Bordetella bronchiseptica (B.b.) was most frequently detected from nasal and oropharynx sites of 7 dogs (10.3%). Among the viruses examined, canine parainfluenza virus (CPIV) was detected with the highest frequency (7.4%). Other pathogens included in the order of frequency group 1 canine coronavirus (4.4%), canine adenovirus type 2 (2.9%), group 2 canine respiratory coronavirus (1.5%), and canine distemper virus (1.5%). Only 2 cases showed mixed infections. Neither influenza A virus nor canine bocavirus (minute virus of canines) was found in any dogs examined. These results indicate that both B.b. and CPIV are likely to be the principal etiologic agents of canine ITB in Japan, and they may be considered as the target for prophylaxis by vaccination.

Atrofia cerebelosa secundaria a cerebelitis aguda por Mycoplasma pneumoniae

Acute cerebellitis is an uncommon complication following Mycoplasma pneumoniae infection. A benign and self-limited course has been described in the few reports found of this association.We report two patients with an apparently M. pneumoniae-induced acute cerebellitis that resulted in cerebellar atrophy. Patients presented with a cerebellar syndrome including ataxia, hypotonia, dysarthric speech and dysmetria, which were preceded by signs of respiratory infection. Initial brain magnetic resonance imaging (MRI) in case 1 was normal but in case 2 it displayed striking cerebellar swelling, small fourth ventricle and supratentorial ventriculomegaly which was self-limited and did not require neurosurgical intervention. Serological studies confirmed a recent M. pneumoniae infection. Case 1 has followed an unfavourable clinical course, with incomplete resolution of cerebellar dysfunction, while case 2 has remained asymptomatic. Follow-up brain MRI have demonstrated prominent cerebellar atrophy in both patients.M. pneumoniae infection should be considered in those patients with acute cerebellitis showing an incomplete resolution of cerebellar dysfunction or those who develop early cerebellar atrophy. The presenting MRI findings do not seem to predict final neurological outcome.

Successful Treatment for Lung Cancer Associated With Pulmonary Sequestration

We encountered a 69-year-old man with lung adenocarcinoma and pulmonary sequestration. The cancer lesion was located in the left upper lobe, with sequestration of the left lower lobe. Left upper lobectomy was performed after induction chemoradiotherapy, but the sequestered lung lobe was preserved because the preoperative respiratory function was poor. Preservation of the sequestered lung during surgery for lung cancer should be considered in patients who have poor respiratory function and no signs of respiratory infection.

Burden of influenza in children in the community.

Influenza vaccination of healthy children is encouraged because children are frequently hospitalized for influenza-attributable illnesses. However, most children with influenza are treated as outpatients, and scarce data are available on the burden of influenza in these children. We performed a prospective study of respiratory infections in preenrolled cohorts of children < or = 13 years old during 2 consecutive respiratory seasons (2231 child-seasons of follow-up). At any sign of respiratory infection, we examined the children and obtained a nasal swab for the detection of influenza. The parents filled out daily symptom diaries. Of all the enrollees, 94% remained active participants in the study. The average annual rate of influenza was highest (179 cases/1000 children) among children < 3 years old. Acute otitis media developed as a complication of influenza in 39.7% of children < 3 years old. For every 100 influenza-infected children < 3 years old, there were 195 days of parental work loss (mean duration, 3.2 days). Influenza causes a substantial burden of illness on outpatient children and their families. Vaccination of children < 3 years old might be beneficial for reducing the direct and indirect costs of influenza in children.

A controlled study of the relationship between Bordetella pertussis infections and sudden unexpected deaths among German infants.

A controlled study of the relationship between Bordetella pertussis infections and sudden unexpected deaths among German infants.

Diagnostics of main bacterial agents of porcine respiratory diseases complex (PRDC) using PCR detection of Mycoplasma hyopneumoniae

The main goal of our work is the presentation and analysis of incidence of porcine respiratory disease complex (PRDC) regarding bacterial agents in the territory of northern districts of Slovakia. Mycoplasma hyopneumoniae and other secondary bacterial causative pathogens of PRDC comprised 75.2% of all cases (98) with clinical signs of respiratory infections that we examined in the course of one year. We present also one of possibilities to the solution of problematic detection of M. hyopneumoniae which is, like the whole rank of mycoplasmas, very difficult to cultivate. This problem was solved by using the PCR method with the direct isolation of M. hyopneumoniae from lungs tissue. In antibiotic sensitivity testing of Pasteurella multocida and Actinobacillus pleuropneumoniae resulted enrofloxacin as the most effective antibiotics in the therapy of PRDC regarding bacterial agents.in above mentioned territory.

Clinical and pathogenetic characteristics of pregnancy rhinitis.

Pregnancy rhinitis is a very common condition. Defined as "nasal congestion present during the last 6 or more weeks of pregnancy without other signs of respiratory tract infection, and with no known allergic cause, disappearing completely within 2 wk after delivery," it strikes one in five pregnant women, and it starts in almost any gestational week. The pathogenesis is not clear, but placental growth hormone is suggested to be involved. Smoking and sensitization to house dust mites are probable risk factors. It is often difficult to make a differential diagnosis from sinusitis, which may in pregnancy present with nasal congestion as the only symptom. Antral irrigation is diagnostic for purulent sinusitis and often needs to be repeated, as it should be treated intensively. Because of changes in pharmacokinetics, increased dosage of betalactam antibiotics is needed during pregnancy. As pregnancy rhinitis reduces quality of life and possibly also affects the fetus, there is often need for treatment. Nasal corticosteroid shave not been shown to be effective. Systemic administration should be avoided,but nasal corticosteroids could be used in pregnancy when indicated for other sorts of rhinitis. Nasal decongestants give good temporary relief, so pregnancy rhinitics tend to overuse them, giving an additional rhinitis medicamentosa. Therefore, use of nasal decongestants should be restricted to a few days. Invasive methods of turbinate reduction may be effective but are not recommendable in this self-limiting condition because of side effects. Nasal saline washings, exercise, and mechanical alar dilators are safe general means to relieve nasal congestion, but the ultimate treatment remains to be found.

Association of clinical signs and symptoms with bacterial findings in acute otitis media.

In acute otitis media (AOM), a means of prediction of the bacterial pathogen based on symptoms and signs would be valuable in selecting appropriate antimicrobial treatment. Children in the control arm (n=831) in the Finnish Otitis Media Vaccine Trial were prospectively observed in a study clinic setting from the age of 2 to 24 months. In patients with AOM, myringotomy with aspiration was performed, and middle ear fluid samples were cultured for bacterial pathogens. Symptoms and signs of respiratory infections were thoroughly recorded. Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenzae were the most common bacterial pathogens. Pneumococcal AOM was associated with more-severe AOM characterized by fever and earache. AOM due to H. influenzae was associated with eye symptoms and findings. Accurate prediction of a bacterial cause of infection based on symptoms and signs of AOM was not possible, but a specific cause was predicted in some situations, with a high probability of applicability to clinical practice.

The etiology and management of pregnancy rhinitis.

Pregnancy rhinitis is defined as nasal congestion in the last 6 or more weeks of pregnancy, without other signs of respiratory tract infection and with no known allergic cause, with complete resolution of symptoms within 2 weeks after delivery. Pregnancy rhinitis occurs in approximately one-fifth of pregnancies, can appear at almost any gestational week, and affects the woman and possibly also the fetus. The pathogenesis of pregnancy rhinitis is not clear, but placental growth hormone is suggested to be involved. Smoking and sensitization to house dust mites are probable risk factors. It is often difficult to make a differential diagnosis from sinusitis: nasendoscopy of a decongested nose is the diagnostic method of choice. In some cases ultrasound or x-ray may be necessary. Sinusitis should be treated aggressively with increased doses of beta-lactam antibiotics and antral irrigation. Nasal decongestants give good temporary relief from pregnancy rhinitis, but they tend to be overused, leading to the development of rhinitis medicamentosa. Corticosteroids have not been shown to be effective in pregnancy rhinitis, and their systemic administration should be avoided during pregnancy. Nasal corticosteroids may be administered to pregnant women when indicated for other sorts of rhinitis. Nasal alar dilators and saline washings are safe means to relieve nasal congestion, but the ultimate treatment for pregnancy rhinitis remains to be found.

Nasal-associated lymphoid tissue (NALT): frequency and localization in young children.

In mucosal immunology nasal-associated lymphoid tissue (NALT) is taken as a constitutive structure of the nasal immune system and as a target tissue in strategies of local defence and an induction site for vaccination. These concepts are based on findings in rodents, but it has not been investigated systematically whether NALT also is present in humans and if so in which amount and localization. In a postmortem study the presence of NALT in humans is documented as a morphologically distinct structure additional to the lymphoid structures of the Waldeyer's ring. Human nasal tissue blocks of 150 children who had died in the first two years of life either of sudden infant death (n = 109) without signs of respiratory tract infections or of different traumatic (n = 22) and natural causes of death (n = 19) were obtained using a specific autopsy-technique and were investigated systematically using histology. Clearly in contrast to rodents human NALT was found disseminated in the nasal mucosa with typical morphological features in 38% of all children, mainly in the middle concha, with similar morphology and frequency in the examined groups. No correlation was found between the presence of NALT and the cause of death and especially the grade of inflammation in general. Therefore, NALT might be the morphological basis for inhalative vaccination strategies in young children and play a role in mucosal host defence.

Applicability of a real-time quantitative PCR assay for diagnosis of respiratory syncytial virus infection in immunocompromised adults.

Respiratory syncytial virus (RSV) accounts for the majority of respiratory virus infections, producing high mortality rates in immunocompromised patients with hematologic malignancies. The available methods for the rapid detection of RSV by antigen detection or PCR either lack sensitivity, require complex laboratory manipulation, or have not been evaluated in this patient population. To assess the applicability of a TaqMan-based real-time PCR technique for the detection of RSV A and B in immunocompromised adults, we developed a rapid, sensitive detection method that simultaneously detects RSV A and B and can be applied in routine diagnostics. The specificity of the assay was assessed using a panel of reference strains of other respiratory viruses and RSV. Electron microscopy-counted stocks of RSV A and B were used to develop a quantitative PCR format. Eleven copies of viral RNA could be detected for RSV A strain Long, and 14 copies could be detected for RSV B strain 9320, corresponding to 50% tissue culture infective doses of 0.86 and 0.34, respectively. The assay was evaluated on 411 combined nose and throat swabs derived from immunocompromised adults with or without signs of respiratory tract infection. The diagnostic efficacy of the TaqMan PCR determined on the clinical samples showed that this real-time PCR technique was substantially more sensitive than the combination of conventional viral culture and shell vial culture. None of the clinical specimens derived from patients without signs of respiratory illness were found to be positive for RSV by real-time TaqMan PCR.

Risk factors for nosocomial pneumonia in a geriatric hospital: a control-case one-center study.

To determine the risk factors (RFs) and the incidence of nosocomial pneumonia (NP). Control/case study conducted from January 1 to April 15, 1999. Prospective enrollment. Geriatric university hospital with long-, intermediate-, and short-term care facilities. Inpatients aged 65 and older with NP. NP diagnosis relied on at least two clinical signs of respiratory infection and on chest radiography. Each NP case was randomly paired with two controls and followed up for 30 days to determine complication and mortality rates. RFs between cases and controls were compared (chi-square test, odds ratio (OR), 95% confidence interval, significance level P =.05). RFs that were significant in univariate analysis were tested using multivariate analysis and logistic regression. Seventy-five cases of NP were diagnosed in 2,142 patients. The average incidence rate was 3.5% (short-term facilities = 0.5%; intermediate-term facilities = 8.3%; long-term care facilities = 5.3%). The complication rate was 58.1%. The most frequent complications were recurrent NP, heart and respiratory failure, phlebitis, and pressure ulcers. The NP mortality rate was 12.2%. The independent RFs of NP were a history of NP during the previous 6 months (OR = 4.50) and oxygen therapy (OR = 16.15), P <.001. Additional RFs were severe malnutrition, heart failure, prescription of antibiotics during the month preceding the emerging NP, eating dependency, and feeding by nasogastric tube. The main RF for NP is a history of pneumonia. NP prevention in geriatrics should rely on early management of respiratory infections and malnutrition, surveillance of oxygen therapy and enteral feeding, rational use of antibiotics, and adaptation to the patient's dependency.