Sushil K. Kabra

Concurrent infections by all four dengue virus serotypes during an outbreak of dengue in 2006 in Delhi, India.

BackgroundCo-circulation of multiple dengue virus serotypes has been reported from many parts of the world including India, however concurrent infection with more than one serotype of dengue viruses in the same individual is rarely documented. An outbreak of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) occurred in and around Delhi in 2006. This is the first report from India with high percentage of concurrent infections with different dengue virus serotypes circulating during one outbreak.ResultsAcute phase sera from patients were tested for the presence of dengue virus RNA by RT-PCR assay. Of the 69 samples tested for dengue virus RNA, 48 (69.5%) were found to be positive. All the four dengue virus serotypes were found to be co-circulating in this outbreak with DENV-3 being the predominant serotype. In addition in 9 of 48 (19%) dengue virus positive samples, concurrent infection with more than one dengue virus serotype were identified.ConclusionThis is the first report in which concurrent infections with different dengue virus serotypes is being reported during an outbreak from India. Delhi is now truly hyperendemic for dengue.

Evaluation of Tuberculosis Diagnostics in Children: 1. Proposed Clinical Case Definitions for Classification of Intrathoracic Tuberculosis Disease. Consensus From an Expert Panel

There is a critical need for improved diagnosis of tuberculosis in children, particularly in young children with intrathoracic disease as this represents the most common type of tuberculosis in children and the greatest diagnostic challenge. There is also a need for standardized clinical case definitions for the evaluation of diagnostics in prospective clinical research studies that include children in whom tuberculosis is suspected but not confirmed by culture of Mycobacterium tuberculosis. A panel representing a wide range of expertise and child tuberculosis research experience aimed to develop standardized clinical research case definitions for intrathoracic tuberculosis in children to enable harmonized evaluation of new tuberculosis diagnostic technologies in pediatric populations. Draft definitions and statements were proposed and circulated widely for feedback. An expert panel then considered each of the proposed definitions and statements relating to clinical definitions. Formal group consensus rules were established and consensus was reached for each statement. The definitions presented in this article are intended for use in clinical research to evaluate diagnostic assays and not for individual patient diagnosis or treatment decisions. A complementary article addresses methodological issues to consider for research of diagnostics in children with suspected tuberculosis.

Three day versus five day treatment with amoxicillin for non-severe pneumonia in young children: a multicentre randomised controlled trial.

Abstract Objective To assess the efficacy of three days versus five days of treatment with oral amoxicillin for curing non-severe pneumonia in children. Design Randomised, double blind, placebo controlled multicentre trial. Setting Outpatient departments of seven referral hospitals in India. Participants 2188 children aged 2-59 months, 1095 given three days of treatment and 1093 given five days. Intervention Oral amoxicillin 31-54 mg/kg/day in three divided doses. Main outcome measures Treatment failure: defined as development of chest indrawing, convulsions, drowsiness, or inability to drink at any time; respiratory rate above age specific cut points on day 3 or later; or oxygen saturation by pulse oximetry < 90% on day 3. Results The clinical cure rates with three days and five days of treatment were 89.5% and 89.9%, respectively (absolute difference 0.4 (95% confidence interval - 2.1 to 3.0)). Adherence to treatment regimen was 94% and 85% for three day and five day treatments, respectively. Loss to follow up was 5.4% by day 5. There were no deaths, 41 hospitalisations, and 36 minor adverse reactions. There were 225 (10.3%) clinical failures and 106 (5.3%) relapses, and rates were similar in both treatments. At enrolment, 513 (23.4%) children tested positive for respiratory syncytial virus, and Streptococcus pneumoniae and Haemophilus influenzae were isolated from the nasopharynx in 878 (40.4%) and 496 (22.8%) children, respectively. Clinical failure was associated with isolation of respiratory syncytial virus (adjusted odds ratio 1.95 (95% confidence interval 1.0 to 3.8)), excess respiratory rate of > 10 breaths/minute (2.89 (1.83 to 4.55)), and non-adherence with treatment at day 5 (11.57 (7.4 to 18.0)). Conclusions Treatment with oral amoxicillin for three days was as effective as for five days in children with non-severe pneumonia.

Co-infections with Chikungunya Virus and Dengue Virus in Delhi, India

Aedes aegypti mosquitoes are common vectors for dengue virus and chikungunya virus. In areas where both viruses cocirculate, they can be transmitted together. During a dengue outbreak in Delhi in 2006, 17 of 69 serum samples were positive for chikungunya virus by reverse transcription–PCR; 6 samples were positive for both viruses.

Dengue haemorrhagic fever in children in the 1996 Delhi epidemic

An epidemic of dengue haemorrhagic fever (DHF) occurred in Delhi in 1996. A total of 240 children between the age of 4 months to 13 years of either sex, admitted in one hospital, were evaluated. Two hundred and sixteen (90%) children were from Delhi. A clinical diagnosis of dengue fever (DF) was made in 25 (10%), dengue fever with unusual bleeding (DFB) in 22 (9%), DHF in 80 (33%) and dengue shock syndrome (DSS) in 113 (47%) of the children strictly according to the WHO classification. The age peaked at 8 years. There was no association between various grades of severity of illness and age-groups though girls suffered from more severe illness. No association between severity of malnutrition and severity of illness was observed. Tourniquet test was positive in 40% with DF, 18% with DFB, 62% with DHF and 64% with DSS. In DSS haematemesis was present in 55 (49%), epistaxis in 39 (35%), melaena in 27 (24%) and ecchymosis in 34 (30%) patients. Children diagnosed as DFB had haematemesis and epistaxis in 12 (55%) and 10 (45%) respectively. Intravenous fluid requirement was clearly less in DFB patients than in DHF/DSS patients. Unusual clinical features in the form of jaundice were present in 7 (6%), hepatic encephalopathy in 6 (5%) and dengue encephalopathy in 6 (5%) patients. Dengue 2 virus was isolated from 10 of the 50 patients for whom viral culture was done on C6/36 clone of Aedes albopictus cell line. Eighteen patients suffering from DSS died giving an overall case fatality of 7.5%. The mortality rate in DHF/DSS was 9.3%. It is further suggested that DFB is a distinct entity. Most patients could be classified by the WHO classification if a retrospective packed cell volume was used to assess haemoconcentration. We suggest that development of area-specific criteria for diagnosis and management is desirable.

Upper respiratory tract infections.

Acute respiratory infections accounts for 20–40% of outpatient and 12–35% of inpatient attendance in a general hospital. Upper respiratory tract infections including nasopharyngitis, pharyngitis, tonsillitis and otitis media constitute 87.5% of the total episodes of respiratory infections. The vast majority of acute upper respiratory tract infections are caused by viruses. Common cold is caused by viruses in most circumstances and does not require antimicrobial agent unless it is complicated by acute otitis media with effusion, tonsillitis, sinusitis, and lower respiratory tract infection. Sinusitis is commonly associated with common cold. Most instances of rhinosinusitis are viral and therefore, resolve spontaneously without antimicrobial therapy. The most common bacterial agents causing sinusitis areS. pneumoniae, H. influenzae, M. catarrhalis,S. aureus andS. pyogenes. Amoxycillin is antibacterial of choice. The alternative drugs are cefaclor or cephalexin. The latter becomes first line if sinusitis is recurrent or chronic. Acute pharyngitis is commonly caused by viruses and does not need antibiotics. About 15% of the episodes may be due to Group A beta hemolytic streptococcus (GABS). Early initiation of antibiotics in pharyngitis due to GABS can prevent complications such as acute rheumatic fever. The drug of choice is penicillin for 10–14 days. The alternative medications include oral cephalosporins (cefaclor, cephalexin), amoxicillin or macrolides.

Respiratory viral infections detected by multiplex PCR among pediatric patients with lower respiratory tract infections seen at an urban hospital in Delhi from 2005 to 2007

BackgroundAcute lower respiratory tract infections (ALRI) are the major cause of morbidity and mortality in young children worldwide. Information on viral etiology in ALRI from India is limited. The aim of the present study was to develop a simple, sensitive, specific and cost effective multiplex PCR (mPCR) assay without post PCR hybridization or nested PCR steps for the detection of respiratory syncytial virus (RSV), influenza viruses, parainfluenza viruses (PIV1–3) and human metapneumovirus (hMPV). Nasopharyngeal aspirates (NPAs) were collected from children with ALRI ≤ 5 years of age. The sensitivity and specificity of mPCR was compared to virus isolation by centrifugation enhanced culture (CEC) followed by indirect immunofluorescence (IIF).ResultsFrom April 2005–March 2007, 301 NPAs were collected from children attending the outpatient department or admitted to the ward of All India Institute of Medical Sciences hospital at New Delhi, India. Multiplex PCR detected respiratory viruses in 106 (35.2%) of 301 samples with 130 viruses of which RSV was detected in 61, PIV3 in 22, PIV2 in 17, hMPV in 11, PIV1 in 10 and influenza A in 9 children. CEC-IIF detected 79 viruses only. The sensitivity of mPCR was 0.1TCID50 for RSV and influenza A and 1TCID50 for hMPV, PIV1, PIV2, PIV3 and Influenza B. Mixed infections were detected in 18.8% of the children with viral infections, none detected by CEC-IIF. Bronchiolitis was significantly associated with both total viral infections and RSV infection (p < 0.05). History of ARI in family predisposed children to acquire viral infection (p > 0.05).ConclusionMultiplex PCR offers a rapid, sensitive and reasonably priced diagnostic method for common respiratory viruses.

Evaluation of tuberculosis diagnostics in children: 2. Methodological issues for conducting and reporting research evaluations of tuberculosis diagnostics for intrathoracic tuberculosis in children. Consensus from an expert panel.

Confirming the diagnosis of childhood tuberculosis is a major challenge. However, research on childhood tuberculosis as it relates to better diagnostics is often neglected because of technical difficulties, such as the slow growth in culture, the difficulty of obtaining specimens, and the diverse and relatively nonspecific clinical presentation of tuberculosis in this age group. Researchers often use individually designed criteria for enrollment, diagnostic classifications, and reference standards, thereby hindering the interpretation and comparability of their findings. The development of standardized research approaches and definitions is therefore needed to strengthen the evaluation of new diagnostics for detection and confirmation of tuberculosis in children. In this article we present consensus statements on methodological issues for conducting research of Tuberculosis diagnostics among children, with a focus on intrathoracic tuberculosis. The statements are complementary to a clinical research case definition presented in an accompanying publication and suggest a phased approach to diagnostics evaluation; entry criteria for enrollment; methods for classification of disease certainty, including the rational use of culture within the case definition; age categories and comorbidities for reporting results; and the need to use standard operating procedures. Special consideration is given to the performance of microbiological culture in children and we also recommend for alternative methodological approaches to report findings in a standardized manner to overcome these limitations are made. This consensus statement is an important step toward ensuring greater rigor and comparability of pediatric tuberculosis diagnostic research, with the aim of realizing the full potential of better tests for children.

Successful treatment of Acanthamoeba meningitis with combination oral antimicrobials

Acanthamoeba was implicated as the causative agent of chronic meningitis in three apparently immunocompetent children. Diagnosis was established by cerebrospinal fluid wet mount examination and culture. Two children improved rapidly with combination oral therapy composed of trimethoprim-sulfamethoxazole, rifampin and ketoconazole.

Recurrent pneumonia in children: clinical profile and underlying causes.

Aim: To study the clinical profile and describe the predisposing causes of recurrent pneumonia in Indian children. Methods: The clinical details and the investigations of children presenting with recurrent pneumonia to the paediatric chest clinic services of a tertiary care centre in northern India were reviewed. Results: Seventy children (44M, 26F) presented with recurrent pneumonia over a period of 5 y. Based on the clinical features and the results of the investigations, underlying illness could be identified in 59 children (84%). The most frequent underlying cause for recurrent pneumonia was recurrent aspiration (24.2%), followed by immunodeficiency (15.7%), asthma (14.2%) and structural anomalies (8.6%).