Can we identify acute severe viral lower respiratory tract infection clinically?

Two hundred children below five years of age hospitalized with a clinical diagnosis of acute severe lower respiratory tract infection were enrolled in the study. Nasopharyngeal (NP) aspirate was collected for viral isolation by centrifugation enhanced culture technique. Viruses were isolated from 89 NP aspirates. Clinical features of these 89 children were compared with 111 children whose NP aspirates were negative for viruses. There was significantly higher incidence of breathlessness and rhonchi in children whose nasopharyngeal aspirates yielded virus. Sensitivity,specificity, positive and negative predictive values of breathlessness for severe viral ALRTI were 98%, 10.8%, 46.8% and 85%, respectively. The values for rhonchi were 60%, 56.8%, 58.2%, and 74.1%, respectively. It is concluded that clinical features do not have desirable sensitivity and specificity for identification of ALRTI due to viral etiology.

Etiology of acute lower respiratory tract infection.

OBJECTIVE: To identify pathogens responsible for acute severe lower respiratory tract infection (ALRTI) in under five children by non-invasive methods. METHOD: 95 children hospitalized with acute severe lower respiratory tract infection were investigated for identification of viruses, bacteria, chlamydia or mycoplasma by nasopharyngeal aspirates, blood culture and serology. RESULT: Etiological agents could be identified in 94% of the patients. Viruses from NP aspirate could be isolated in 36 (38%), bacterial isolates from blood cultures in 15 (16%); mycoplasma was identified in 23 (24%) and chlamydia in 10 (11%) by serological tests; mixed infections were present in 8 (8%) patients. CONCLUSION: Noninvasive methods can be useful in identifying etiological agents in severe ALRTI.

Risk factors for severe acute lower respiratory tract infection in under-five children.

BACKGROUND: Acute lower respiratory infection (ALRTI) is the leading cause of death in children below five years of age. Identification of modifiable risk factors of severe ALRTI may help in reducing the burden of disease. METHODS: A hospital based case control study was undertaken to determine risk factors associated with severe lower respiratory tract infection (LRTI) in under-five children. A case definition of severe ALRTI as given by World Health Organization (WHO) was used for cases. Healthy children attending Pediatrics out patient department for immunization during study period were enrolled as controls. Details of potential risk factors in cases and controls were recorded in pre-designed proforma. RESULTS: 512 children including 201 cases and 311 controls were enrolled in the study. On stepwise logistic regression analysis it was found that lack of breastfeeding (OR: 1.64; 95 percent CI: 1.23-2.17); upper respiratory infection in mother (OR: 6.53; 95 percent CI: 2.73-15.63); upper respiratory infection in siblings (OR: 24; 95 percent CI: 7.8-74.4); severe malnutrition (OR: 1.85; 95 percent CI: 1.14-3.0); cooking fuel other than liquid petroleum gas (OR: 2.5; 95 percent CI: 1.51-4.16); inappropriate immunization for age (OR: 2.85; 95 percent CI 1.59-5.0) and history of LRTI in the family (OR 5.15, 95 percent CI 3.0-8.8) were the significant contributors of ALRTI in children under five years. Sex of the child, age of the parents, education of the parents, number of children at home, anemia, inadequate caloric intake, type of housing were not documented to be significant risk factors of ALRTI. CONCLUSION: Lack of breast-feeding, upper respiratory infection in mother, upper respiratory infection in siblings, severe malnutrition, cooking fuel other than liquid petroleum gas, inappropriate immunization for age and history of LRTI in the family were the significant risk factors associated with ALRTI

Incidence, clinical spectrum, and outcome of intrauterine infections in neonates.

A prospective study was undertaken on the incidence of intrauterine infections by screening 1302 cord blood samples for total IgM by radial immunodiffusion. Specific IgM against cytomegalovirus (CMV), rubella and Toxoplasma were estimated in cord blood samples found to contain total IgM > 20 mg/dl. All these neonates were examined at birth and at discharge. Cord blood samples with total IgM > 20 mg/dl were further screened for specific IgM against rubella, CMV and Toxoplasma. Neonates found to have positive specific IgM were followed-up for hearing, opthalmological and developmental assessment. Raised cord blood (IgM > 20 mg/dl) was found in 270/1302 (20.6 per cent). Mean birth weight was comparable in babies with raised (> 20 mg/dl) or low (< 20 mg/dl) cord blood total IgM. Incidence of prematurity and low birth weight were not statistically different in babies with raised cord blood IgM when compared to those with low cord blood IgM levels. Similarly, incidence of intrauterine growth retardation (IUGR) idiopathic was similar in two groups. Specific IgM for rubella was found to be positive in eight (0.6 per cent). Of these, three had symptomatic rubella infection. Two mothers of these symptomatic babies had exanthematous viral illness during first trimester. Specific IgM for CMV was found to be positive in 23 (1.8 per cent) while two infants had symptomatic CMV disease. None of the babies was found to have specific IgM against Toxoplasma. One baby with symptomatic CMV disease and one with rubella died. Another baby with symptomatic CMV disease developed neonatal hepatitis which improved on follow-up but the infant went on to develop sensorineural deafness. All other asymptomatic babies with specific IgM positive against rubella and CMV were found to have normal vision, hearing and development on follow-up.

Rapid detection of respiratory viruses by centrifugation enhanced cultures from children with acute lower respiratory tract infections.

BACKGROUND: Acute respiratory tract infection (ARI) is the major cause of morbidity and mortality in young children in developing countries. Information on viral aetiology in ARI in India is very limited. OBJECTIVE: The aim of the study was to define the role of viruses in acute lower respiratory tract infections (ALRTI) in children in India using centrifugation enhanced cultures followed by indirect immunofluorescence (IIF). STUDY DESIGN: Nasopharyngeal aspirates (NPAs) were collected from children from September 1995 to April 1997, attending paediatric clinic of All India Institute of Medical Sciences (AIIMS) with symptoms of ALRTI. Virus isolation was done by centrifugation enhanced cultures using HEp-2, LLC-MK2 and MDCK cells. The viruses were identified at 24-48 h post inoculation by IIF staining using monoclonal antibodies to respiratory syncytial virus (RSV), parainfluenza virus (PIV), influenza virus and adenovirus. RESULTS: Of 200 NPA samples, 89 (44.5%) were positive for one or more viral pathogens. RSV was detected in 34 (17%) of all ALRTI cases followed by influenza viruses in 29 (14.5%), PIVs in 23 (11.5%) and adenoviruses in three (1.5%). In 79 children with bronchiolitis, RSV was most frequently isolated (25%) pathogen, while in bronchopneumonia cases (101) the most common viral pathogen was influenza virus (17%). In eight cases (4%) of ALRTI dual infections were detected. In 100 NPA specimens IIF staining on direct cell smears was carried out and viruses were detected in only 17%. RSV and influenza virus infection peaked from September to December, where as PIV infections were more frequent from January to April. CONCLUSION: Respiratory viruses accounted for 44.5% of cases of ALRTI in India and the results of viral aetiology could be given in 24-48 h using centrifugation enhanced cultures. RSV was the most common viral agent associated with ALRTI in children under 5 years of age with greater association with bronchiolitis.

Acute hemorrhagic conjunctivitis due to enterovirus 70 in India.

An outbreak of acute hemorrhagic conjunctivitis occurred in Delhi, India, during August and September 1996. The etiologic agent was confirmed as enterovirus type 70 by a modified centrifugation-enhanced culture method followed by immunofluorescence and neutralization tests. After nearly a decade, this virus is reemerging as a cause of acute hemorrhagic conjunctivitis in India.