Background: Co-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. Results: Acute 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. Conclusion: This 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.

Background: Acute 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). Results: From 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). Conclusion: Multiplex PCR offers a rapid, sensitive and reasonably priced diagnostic method for common respiratory viruses.

Background: Pneumonia is one of the leading causes of morbidity and mortality in under fives. We carried out a comprehensive study to identify factors influencing both mortality and morbidity for children less than 5 years of age hospitalized with severe pneumonia.Methods: 200 hospitalized children aged 2–60 months with World Health Organization (WHO) defined severe pneumonia were enrolled in the study. The children were managed using a standard protocol. They were closely followed up for need for change in antibiotics, prolonged hospital stay, need for mechanical ventilation and mortality. Data on the factors influencing the outcome were collected.Results: Of 200 children enrolled in the study, 113 (56.5%) needed a change in antibiotics, 102 (51%) stayed for more than 5 days in the hospital, 41 (20.5%) needed mechanical ventilation and 21 (10.5%) died. On multivariate analysis, lack of exclusive breastfeeding [RR (95%CI) 2.63 (2.16–2.86)], overcrowding [RR (95%CI) 1.94 (1.35–2.38)] and an abnormal chest x-ray [RR (95%CI) 2.29 (1.22–3.44)] were associated with the need for change of antibiotics. Lack of exclusive breastfeeding [RR (95%CI) 2.56 (2.0–2.93)], overcrowding [RR (95%CI) 2.59 (1.78–3.23)] and an abnormal chest x-ray [RR (95%CI) 2.99 (1.65–4.38)] were identified as determinants for prolonged hospital stay. Head nodding [RR (95%CI) 8.34 (2.71–12.77)], altered sensorium [RR (95%CI) 5.44 (1.34–17.56)], abnormal leukocyte counts [RR (95%CI) 5.85(1.36–17.14)] and pallor [RR (95%C) 10.88 (2.95–20.40)] were associated with mortality. Head nodding (RR (95% CI) 4.73 (1.50–6.36)] and cyanosis (RR (95%CI) 5.06 (1.80–11.34)] were the determining factors for mechanical ventilation.In radiographically confirmed pneumonia, the determining factors for change of antibiotics were: lack of exclusive breast feeding [RR (95% CI) 2.05 (1.69–2.2)] and low birth weight [RR (95% CI) 1.59 (1.1–1.89)]. For prolonged hospital stay, the factors identified were mothers' education less than graduation [RR (95% CI) 1.5 (1.19–1.7)], lack of exclusive breast feeding [RR (95% CI) 1.77 (1.19–2.09)] and oxygen saturation of < 90% at time of presentation [RR (95% CI) 2.06 (1.42–2.42)]. Determinants for mechanical ventilation were mothers' education less than graduation [RR (95% CI) 3.6 (1.15–6.3)] and cyanosis at presentation [RR (95% CI) 10.9 (1.56–18.9)]. For mortality, the only determinant was pallor [RR (95% CI) 10.54 (1.8–21.79)].Conclusion: Children hospitalized with severe community acquired pneumonia [as defined by World Health Organization (WHO)] who had not received exclusive breast feeding, had stayed in an overcrowded homes and had an abnormal chest radiograph were more likely to fail to respond with primary antibiotic regimen and require change of antibiotics and prolonged hospital stay.In children with radiographically confirmed pneumonia, lack of breast feeding and low birth weight was associated with need for change in antibiotics.

Background: Widespread use of fluoroquinolones has resulted in emergence of Salmonella typhi strains with decreased susceptibility to fluoroquinolones. These strains are identifiable by their nalidixic acid-resistance. We studied the impact of infection with nalidixic acid-resistant S. typhi (NARST) on clinical outcomes in patients with bacteriologically-confirmed typhoid fever. Methods: Clinical and laboratory features, fever clearance time and complications were prospectively studied in patients with blood culture-proven typhoid fever, treated at a tertiary care hospital in north India, during the period from November 2001 to October 2003. Susceptibility to amoxycillin, co-trimoxazole, chloramphenicol, ciprofloxacin and ceftriaxone were tested by disc diffusion method. Minimum inhibitory concentrations (MIC) of ciprofloxacin and ceftriaxone were determined by E-test method. Results: During a two-year period, 60 patients (age [mean ± SD]: 15 ± 9 years; males: 40 [67%]) were studied. All isolates were sensitive to ciprofloxacin and ceftriaxone by disc diffusion and MIC breakpoints. However, 11 patients had clinical failure of fluoroquinolone therapy. Infections with NARST isolates (47 [78%]) were significantly associated with longer duration of fever at presentation (median [IQR] 10 [7-15] vs. 4 [3-6] days; P = 0.000), higher frequency of hepatomegaly (57% vs. 15%; P = 0.021), higher levels of aspartate aminotransferase (121 [66–235] vs. 73 [44–119] IU/L; P = 0.033), and increased MIC of ciprofloxacin (0.37 ± 0.21 vs. 0.17 ± 0.14 μg/mL; P = 0.005), as compared to infections with nalidixic acid-susceptible isolates. All 11 patients with complications were infected with NARST isolates. Total duration of illness was significantly longer in patients who developed complications than in patients who did not (22 [14.8–32] vs. 12 [9.3–20.3] days; P = 0.011). Duration of prior antibiotic intake had a strong positive correlation with the duration of fever at presentation (r = 0.61; P = 0.000) as well as the total duration of illness (r = 0.53; P = 0.000). Conclusion: Typhoid fever caused by NARST infection is associated with poor clinical outcomes, probably due to delay in initiating appropriate antibiotic therapy. Fluoroquinolone breakpoints for S. typhi need to be redefined and fluoroquinolones should no longer be used as first-line therapy, if the prevalence of NARST is high.