Emergence of 2009A/H1N1 cases in a tertiary care hospital in New Delhi, India

Abstract

Please cite this paper as: Broor et al. (2011) Emergence of 2009A/H1N1 cases in a tertiary care hospital in New Delhi, India. Influenza and Other Respiratory Viruses 5(6), e552–e557. Objective To determine virologic and epidemiologic characteristics of pandemic (H1N1) 2009 at All India Institute of Medical Sciences (AIIMS) a tertiary care hospital in New Delhi, India. Methods Nasal and throat swabs from patients with febrile acute respiratory illness (FARI) from August to December 2009 (n = 1401) were tested for 2009A/H1N1 and seasonal influenza A viruses by real‐time RT‐PCR. Results Of 1401 samples tested, 475 (33·9%) were positive for influenza A, of these majority (412; 87%) were 2009A/H1N1, whereas the remaining 63 (13%) were seasonal influenza A (49 were A/H3 and 14 were A/H1). While co‐circulation of 2009A/H1N1 and A/H3 was observed in August–September, subsequent months had exclusive pandemic influenza activity (October–December 2009). Pandemic 2009A/H1N1 emergence did not follow typical seasonal influenza seasonality in New Delhi, which normally peaks in July–August, but instead showed bimodal peaks in weeks 39 and 48 in 2009. The percent of specimens testing positive for 2009A/H1N1 influenza virus was found to be highest in >5‐ to 18‐year age group (41·2%; OR = 2·3; CI = 1·6–3·2; P = 0·00). Conclusions Taken together, our data provide high prevalence of pandemic 2009A/H1N1 in urban New Delhi with bimodal peaks in weeks 39 and 48 and highest risk group being the children of school‐going age (aged >5–18).

Validity of clinical case definitions for influenza surveillance among hospitalized patients: results from a rural community in North India

“…All seasonal influenza A positive samples not positive for A(H1N1)pdm09 were further subtyped using primers and probes for A/H1 and A/H3 18 . Samples positive by rRT‐PCR were inoculated in Madin‐Darby Canine Kidney (MDCK) cells for virus isolation followed by haemagglutination inhibition for virus identification and subtyping 19 . The clinical features of the patients were unknown to the laboratory personnel.…”

Clinical Profile of Patients With Influenza Like Illness

“…Diabetes mellitus was the most common co morbidity seen among the patients. 10 Most of the patients presented within 7 days of illness. Fever, cough and breathlessness were the most common symptoms during presentation.…”

“…In other similar studies conducted in India, fever was the most common presenting symptom. (9,10) Even though majority of patients presented to us before 7 days of illness and despite starting treatment as soon as they presented, the severity of the disease was not altered. Most of the patients had moderate ARDS.…”

Disparities in spread and control of influenza in slums of Delhi: findings from an agent-based modelling study

“…These rates are generally higher than those in some other studies that either compute experimental attack rates from cases or compute them in modelling studies such as this one. Attack rates used by past researchers for different strains of influenza include Asia (0.22–0.50), 30 South-East Asia (0.11–0.31 in children 31 ; 0.05–0.65 32 ) and India (0.111–0.235 33 ; 0.074–0.424 34 ; 0.045–0.294 35 ; 0.008–0.100 36 ; 0.209 for various strains 13 ). The results in Chen et al 4 indicate that the results here, for this particular transmissibility, will be qualitatively the same for other transmissibilities, but will scale down or up as transmissibility changes in the same direction.…”