Pandemic and seasonal influenza viruses among patients with acute respiratory illness in Kashmir (India)

Prevalence and Surveillance of Influenza Viruses in Hospitalized Patients with Respiratory Infections in and Around Chennai, Southern Part of India

The COVID-19 pandemic has heightened concerns about increasing cases of human influenza virus, which pose a significant public health threat to the population in and around Chennai. Therefore, this study analyzed the prevalence of influenza viruses, including influenza A (InfA) and its subtypes H1N1 and H3N2, influenza B (InfB), and respiratory syncytial virus (RSV), in the population of Chennai and surrounding areas. The study included 444 nasopharyngeal and oropharyngeal samples collected between September 2022 and March 2023 from hospitalized patients with severe respiratory symptoms. The sample group consisted of 249 men and 195 women between the ages of 1 and 100 years. The collected samples were processed for detection of InfA, H1N1, H3N2, InfB, and RSV according to the guidelines of the Indian Council of Medical Research (ICMR) and the Department of Public Health, Government of Tamil Nadu. InfA and H3N2 were found to be the most prevalent, with prevalence rates of 11.4%, and 5.1%, respectively. They were followed by H1N1 (3.1%), InfB (2.02%), and RSV (0.5%). H3N2 was more frequently observed in adults and elderly aged groups (4.5%). The most common symptoms associated with InfA infection were fever, body aches, cough, and headache. In addition, RSV, H1N1, and H3N2 viral positivity (11.4%, 5.1%, and 0.5%, respectively) were higher in children aged 1-5 years. This study shows that H1N1 and H3N2 viruses were the predominant strains during the study period in Chennai and provides valuable information for public awareness and preventive measures against early influenza virus infections.

The Cat Que Virus: a resurfacing orthobunyavirus could lead to epidemics

The newly emerging and re-emerging of viral contagion in the present scenario are of more extensive health concern. After a long calm of many years, an unexpected eruption of the Cat Que Virus in China is a source of our concern. Cat Que Virus is an Arbovirus and belongs to the Simbu serogroup of the Orthobunyavirus genus of the Bunyaviridae family. The Simbu serogroup is an extremely diverse group of Arbovirus. The arboviruses are causing the infection in multiple hosts including humans and various livestock. They can cause mild to life-threatening infections. Arboviruses expand their spectrum and are more observable in recent times. Human actions have the most significant geophysical impact on the environment. Changes in rainfall patterns, floods, and the risk of extreme weather events are all consequences of climate change. These events may be connected to the extension of permissive vectors, geographic ranges, and therefore provide more chance of growth and spread of potential vector. Arboviruses are responsible for the health hazard to millions of people globally. It is critical to concentrate research and surveillance on these emerging and re-emerging viruses, particularly arthropod-borne viral infections. The appropriate research and surveillance on them will help us for the development of effective control and treatment strategies and also reduce health problems. The present review summarizes the current broad outline of discovery, evolution and dispersal of this unknown virus.

Poor Vaccine Effectiveness against Influenza B-Related Severe Acute Respiratory Infection in a Temperate North Indian State (2019-2020): A Call for Further Data for Possible Vaccines with Closer Match

Background: Influenza vaccine uptake in India is poor, and scant data exist regarding the effectiveness of influenza vaccine against hospitalization. Methods: From October 2019 to March 2020, vaccination status of 1219 patients (males n = 571, aged 5–107 years; median, 50 years) hospitalized with severe acute respiratory illness (SARI) was assessed. The patients were tested for influenza viruses and their subtypes by RT PCR. Sequencing of the HA gene was performed. Vaccine effectiveness (VE) against influenza subtypes was estimated by the test negative design. Results: A total of 336 (27.5%) patients were influenza-positive, with influenza B/Victoria accounting for 49.7% (n = 167), followed by influenza A/H1N1 (47.6%; n = 155) and influenza A/H3N2 (4.4%; n = 15). About 6.8% and 8.6% of the influenza-positive and influenza-negative patients, respectively, had been vaccinated. Adjusted VE for any influenza strain was 13% (95% CI −42 to 47), which for influenza B was 0%. HA sequencing revealed that influenza B samples mainly belonged to subclade V1A.3/133R with deletion of residues 163–165, as against the 2-aa deletion in influenza B/Colorado/06/2017 strain, contained in the vaccine. VE for influenza A/H1N1 was 55%. Conclusions: Poor VE due to a genetic mismatch between the circulating strain and the vaccine strain calls for efforts to reduce the mismatch.

Indoor Environmental Factors and Acute Respiratory Illness in a Prospective Cohort of Community-Dwelling Older Adults

BACKGROUND

Ambient environmental factors have been associated with respiratory infections in ecological studies, but few studies have explored the impact of indoor environmental factors in detail. The current study aimed to investigate the impact of indoor environment on the risk of acute respiratory illness (ARI) in a subtropical city.

METHOD

A prospective cohort study was conducted in 285 community-dwelling older adults from December 2016 through May 2019. Individual household indoor environment data and ARI incidence were continuously collected. A time-stratified case-crossover analysis was conducted to estimate the excess risk of ARI associated with per-unit increase of daily mean indoor temperature, relative humidity, and absolute humidity (AH).

RESULT

In total, 168 episodes of ARI were reported with an average risk of 36.8% per year. We observed a negative association of ARI with indoor AH up to 5 lag days in cool seasons, with a 6-day cumulative excess risk estimate of -9.0% (95% confidence interval, -15.9% to -1.5%). Negative associations between household temperature or relative humidity and ARI were less consistent across warm and cool seasons.

CONCLUSIONS

Lower indoor AH in household was associated with a higher risk of ARI in the community-dwelling older adults in Hong Kong during cold seasons.

Influenza B in a temperate region of northern India 2010-2016: co-circulation of the two lineages with northern hemispherical seasonality

Scant data exist about the epidemiology of influenza B in India. We set out to address the epidemiology of influenza B in a temperate region of northern India from 2010 to 2016. Outpatient and inpatient surveillance was conducted in patients presenting with acute respiratory infection in a northern Indian hospital from September 2010 till April 2016. After recording clinical data, combined nasal/throat swabs were collected and tested for influenza viruses by real time RT-PCR. Influenza A viruses were further subtyped into A/H3N2 and A/H1N1 whereas influenza B were differentiated into B/Yamagata and B/Victoria. Virus isolation, haemaggglutination inhibition testing, sequencing and phylogenetic analysis was carried out on representative samples. Of the 6879 recruited cases, influenza B was detected in 299 (4.3%). The patients presented with respiratory symptoms of varying duration; cough, fever and nasal discharge being the most common. The peaking of the activity of the circulation showed a correlation with the onset of the winter with reduced temperatures and high dry humidity. B/Victoria lineage was detected in 35.4% (n = 106/299) whereas 53.8% (n = 161/299) were B/Yamagata. The circulation in each season was dominated by one lineage which correlated with the vaccine strain, but up to 37% consisted of a different lineage. We conclude that Influenza B exhibits a northern hemispherical seasonality in temperate northern India with co-circulation of the 2 lineages of influenza B. These findings have relevance for vaccine effectiveness and argue for vaccination with a quadrivalent influenza vaccine.

The 2015 Outbreak of Severe Influenza in Kashmir, North India: Emergence of a New Clade of A/H1n1 Influenza Virus

Introduction: Following the initial outbreak of A/H1N1pdm09, periodic resurgences of the virus, with variable morbidity and mortality, have been reported from various parts of India including the temperate Kashmir region of northern India. An outbreak of A/H1N1 was reported in early 2015 across India with a high morbidity and mortality. We studied patients during the outbreak in Kashmir.

Methods: Patients (n=1780, age 1 month to 90 years, median 35 years) presenting with acute respiratory illness to a tertiary care hospital in Srinagar, Kashmir from October 2014 to April 2015 were recruited. After clinical data recording, combined throat and nasal swabs were collected in viral transport medium and tested by real-time RT-PCR for influenza viruses. All influenza A positive samples were further subtyped using primers and probes for A/H1N1pdm09 and A/H3 whereas influenza B samples were further subtyped into B/Yamagata and B/Victoria lineages. Virus isolation, hemagglutination inhibition testing, sequencing and phylogenetic analysis was carried out using standard procedures. Testing for H275Y mutation was done to determine sensitivity to oseltamivir. All patients received symptomatic therapy and influenza positive patients were administered oseltamivir.

Results: Of the 1780 patients, 540 (30%) required hospitalization and 533 tested positive for influenza [influenza A=517(A/H1N1pdm09=437, A/H3N2=78 with co-infection of both in 2 cases); influenza B=16 (B/Yamgata=15)]. About 14% (n=254) had been vaccinated against influenza, having received the NH 2014-15 vaccine, 27 (11.3%) of these testing positive for influenza.  Sixteen patients, including 4 pregnant females, died due to multi-organ failure. HA sequencing depicted that 2015 isolates belonged to Clade 6B.1. No H275Y mutation was reported from A/H1N1 positives.

Conclusion: Resurgent outbreak of A/H1N1pdm09, with emergence of clade 6B.1, in 2014-15 resulted in high rate of hospitalizations, morbidity and mortality. Periodic resurgences and appearance of mutants emphasize continued surveillance so as to identify newer mutations with potential for outbreaks and severe outcomes.

Performance of rapid influenza diagnostic tests (QuickVue) for influenza A and B Infection in India

BACKGROUND

Rapid point-of-care (POC) tests provide an economical alternative for rapid diagnosis and treatment of influenza, especially in public health emergency situations.

OBJECTIVES

To test the performance of a rapid influenza diagnostic test, QuickVue (Quidel) as a POC test against a real-time polymerase chain reaction (RT-PCR) assay for detection of influenza A and B in a developing country setting.

STUDY DESIGN

In a prospective observational design, 600 patients with influenza-like illness (ILI) or with severe acute respiratory illness (SARI) who were referred to the Influenza Clinic of a tertiary care hospital in Srinagar, India from September 2012 to April 2013, were enrolled for diagnostic testing for influenza using QuickVue or RT-PCR. All influenza A-positive patients by RT-PCR were further subtyped using primers and probes for A/H1pdm09 and A/H3.

RESULTS

Of the 600 patients, 186 tested positive for influenza A or B by RT-PCR (90 A/H1N1pdm09, 7 A/H3 and 89 influenza B), whereas only 43 tested positive for influenza (influenza A=22 and influenza B=21) by QuickVue. Thus, the sensitivity of the QuickVue was only 23% (95% confidence interval, CI: 17.3-29.8) and specificity was 100% (95% CI: 99.1-100) with a positive predictive value (PPV) of 100% (95% CI 91.8-100) and a negative predictive value (NPV) of 74.3% (95% CI: 70.5-77.9) as compared to RT-PCR.

CONCLUSIONS

The high specificity of QuickVue suggest that this POC test can be a useful tool for patient management or triaging during a public health crisis but a low sensitivity suggests that a negative test result need to be further tested using RT-PCR.

Differences in influenza seasonality by latitude, northern India

The seasonality of influenza in the tropics complicates vaccination timing. We investigated influenza seasonality in northern India and found influenza positivity peaked in Srinagar (34.09°N) in January–March but peaked in New Delhi (28.66°N) in July–September. Srinagar should consider influenza vaccination in October–November, but New Delhi should vaccinate in May–June.

An outbreak of influenza B in an isolated nomadic community in Jammu & Kashmir, India

BACKGROUND & OBJECTIVES

Community outbreaks of disease amongst nomadic populations generally remain undocumented. Following a reported increase in acute respiratory tract infections (ARI) in May 2011 in a nomadic population of Sangerwini in Jammu & Kashmir, India, we examined the patients with ARI symptoms and their nasal swabs were tested for influenza virus.

METHODS

Patients with ARI (n=526) were screened from May 14 to 23, 2011 and nasopharyngeal swabs collected from 84 with Influenza like illness (ILI) for bacterial cultures and influenza virus testing. Samples were tested for influenza A and influenza B by real time (RT)-PCR.

RESULTS

Twelve (14.3%) of the 84 patients tested positive for influenza B, compared to only one (0.9%) of 108 patients with ILI in a parallel survey performed in Srinagar during the same period, suggesting a localized outbreak in the isolated nomadic community. All presented with respiratory symptoms of less than seven days. Familial clustering was seen in 40 per cent (25% of influenza B positives). Average daytime temperatures ranged from 15-16 ° C compared to 22 ° C in Srinagar. Four patients developed pneumonia whereas others ran a mild course with a total recovery with oseltamivir and symptomatic therapy.

INTERPRETATION & CONCLUSION

Our report of confirmed influenza B in this underprivileged nomadic population argues for routine surveillance with efforts to improve vaccination and infection control practices.

Recrudescent Wave of A/H1N1pdm09 Influenza Viruses in Winter 2012-2013 in Kashmir, India

Some parts of world, including India observed a recrudescent wave of influenza A/H1N1pdm09 in 2012. We undertook a study to examine the circulating influenza strains, their clinical association and antigenic characteristics to understand the recrudescent wave of A/H1N1pdm09 from November 26, 2012 to Feb 28, 2013 in Kashmir, India. Of the 751 patients (545 outpatient and 206 hospitalized) presenting with acute respiratory infection at a tertiary care hospital in Srinagar; 184 (24.5%) tested positive for influenza. Further type and subtype analysis revealed that 106 (58%) were influenza A (H1N1pdm09 =105, H3N2=1) and 78 (42%) were influenza B. The influenza positive cases had a higher frequency of chills, nasal discharge, sore throat, body aches and headache, compared to influenza negative cases. Of the 206 patients hospitalized for pneumonia/acute respiratory distress syndrome or an exacerbation of an underlying lung disease, 34 (16.5%) tested positive for influenza (22 for H1N1pdm09, 11 for influenza B). All influenza-positive patients received oseltamivir and while most patients responded well to antiviral therapy and supportive care, 6 patients (4 with H1N1pdm09 and 2 with influenza B) patients died of progressive respiratory failure and multi-organ dysfunction. Following a period of minimal circulation, H1N1pdm09 re-emerged in Kashmir in 2012-2013, causing serious illness and fatalities. As such the healthcare administrators and policy planners need to be wary and monitor the situation closely.

Skin rash and subconjunctival haemorrhage in an adult with pandemic H1N1 influenza

A young man presented with erythematous rash that appeared 3 days following upper respiratory symptoms and fever. Diffuse exanthematous rash was seen over whole body, most pronounced over the trunk. A subconjunctival haemorrhage also appeared in the left eye following incessant cough. Reverse transcription-PCR of the nasopharyngeal secretions revealed influenza A (2009 pandemic H1N1). The patient responded to oseltamivir therapy. Influenza should be considered in patients presenting with exanthematous skin rash.

Knowledge, attitude, and practices about the seasonal influenza vaccination among healthcare workers in Srinagar, India

Please cite this paper as: Bali NK et al. (2012) Knowledge, attitude, and practices about the seasonal influenza vaccination among healthcare workers in Srinagar, India. Influenza and Other Respiratory Viruses 7(4), 540–545.

Background  Healthcare workers (HCWs) universally have a poor uptake of influenza vaccination. However, no data are available from India.

Objective  To explore knowledge, attitudes, and practices associated with influenza vaccination in HCWs in a temperate climate area in northern India.

Patients and Methods  A self‐administered questionnaire was offered to all HCWs in three major hospitals of Srinagar and information sought on motivations, perceptions, preferences and practices regarding influenza vaccination.

Results  Of the 1750 questionnaires received, 1421 (81%) were returned. Only 62 (4·4%) HCWs had ever received influenza vaccination even as 1348 (95%) believed that influenza poses adverse potential consequences for themselves or their contacts; 1144 (81%) were aware of a vaccine against influenza and 830 (58%) of its local availability. Reasons cited by 1359 participants for not being vaccinated included ignorance about vaccine availability (435; 32%), skepticism about efficacy (248; 18%), busy schedule (166; 12%), fear of side effects (70; 4%), and a perception of not being‐at‐risk (82; 6%). Sixty‐one percent (865) believed that vaccine programs are motivated by profit. Eighty‐eight percent opined for mandatory vaccination for HCWs caring for the high‐risk patients, as a part of ‘employee health program’. Most of the participants intended to get vaccinated in the current year even as 684 (48%) held that vaccines could cause unknown illness and 444 (31%) believed their adverse effects to be underreported.

Conclusion  Influenza vaccination coverage among HCWs is dismally low in Srinagar; poor knowledge of vaccine availability and misperceptions about vaccine effectiveness, fear of adverse effects and obliviousness to being‐at‐risk being important barriers. Multifaceted, adaptable measures need to be invoked urgently to increase the coverage.

Dynamic patterns of circulating seasonal and pandemic A(H1N1)pdm09 influenza viruses from 2007-2010 in and around Delhi, India

Influenza surveillance was carried out in a subset of patients with influenza-like illness (ILI) presenting at an Employee Health Clinic (EHS) at All India Institute of Medical Sciences (AIIMS), New Delhi (urban) and pediatric out patients department of civil hospital at Ballabhgarh (peri-urban), under the Comprehensive Rural Health Services Project (CRHSP) of AIIMS, in Delhi region from January 2007 to December 2010. Of the 3264 samples tested, 541 (17%) were positive for influenza viruses, of which 221 (41%) were pandemic Influenza A(H1N1)pdm09, 168 (31%) were seasonal influenza A, and 152 (28%) were influenza B. While the Influenza viruses were detected year-round, their types/subtypes varied remarkably. While there was an equal distribution of seasonal A(H1N1) and influenza B in 2007, predominance of influenza B was observed in 2008. At the beginning of 2009, circulation of influenza A(H3N2) viruses was observed, followed later by emergence of Influenza A(H1N1)pdm09 with co-circulation of influenza B viruses. Influenza B was dominant subtype in early 2010, with second wave of Influenza A(H1N1)pdm09 in August-September, 2010. With the exception of pandemic H1N1 emergence in 2009, the peaks of influenza activity coincided primarily with monsoon season, followed by minor peak in winter at both urban and rural sites. Age group analysis of influenza positivity revealed that the percent positivity of Influenza A(H1N1)pdm09 influenza virus was highest in >5-18 years age groups (OR 2.5; CI = 1.2-5.0; p = 0.009) when compared to seasonal influenza. Phylogenetic analysis of Influenza A(H1N1)pdm09 from urban and rural sites did not reveal any major divergence from other Indian strains or viruses circulating worldwide. Continued surveillance globally will help define regional differences in influenza seasonality, as well as, to determine optimal periods to implement influenza vaccination programs among priority populations.