Pandemic influenza (H1N1) 2009 is associated with severe disease in India

DNA and protein-generated chimeric molecules for delivery of influenza viral epitopes in mouse and humanized NSG transfer models

Purified subunit viral antigens are weakly immunogenic and stimulate only the antibody but not the T cell-mediated immune response. An alternative approach to inducing protective immunity with small viral peptides may be the targeting of viral epitopes to immunocompetent cells by DNA and protein-engineered vaccines. This review will focus on DNA and protein-generated chimeric molecules carrying engineered fragments specific for activating cell surface co-receptors for inducing protective antiviral immunity. Adjuvanted protein-based vaccine or DNA constructs encoding simultaneously T- and B-cell peptide epitopes from influenza viral hemagglutinin, and scFvs specific for costimulatory immune cell receptors may induce a significant increase of anti-influenza antibody levels and strong CTL activity against virus-infected cells in a manner that mimics the natural infection. Here we summarize the development of several DNA and protein chimeric constructs carrying influenza virus HA317-41 fragment. The generated engineered molecules were used for immunization in intact murine and experimentally humanized NSG mouse models.

Naturally occurring PAE206K point mutation in 2009 H1N1 pandemic influenza viruses impairs viral replication at high temperatures

The emergence of influenza virus A pandemic H1N1 in April 2009 marked the first pandemic of the 21st century. In this study, we observed significant differences in the polymerase activities of two clinical 2009 H1N1 influenza A virus isolates from Chinese and Japanese patients. Sequence comparison of the three main protein subunits (PB2, PB1, and PA) of the viral RNA-dependent RNA polymerase complex and subsequent mutational analysis revealed that a single amino acid substitution (E206K) was responsible for the observed impaired replication phenotype. Further in vitro experiments showed that presence of PAE206K decreased the replication of influenza A/WSN/33 virus in mammalian cells and a reduction in the virus's pathogenicity in vivo. Mechanistic studies revealed that PAE206K is a temperature-sensitive mutant associated with the inability to transport PB1-PA complex to the nucleus at high temperature (39.5 ​°C). Hence, this naturally occurring variant in the PA protein represents an ideal candidate mutation for the development of live attenuated influenza vaccines.

Fitness Determinants of Influenza A Viruses

Influenza A (IAV) is a major human respiratory pathogen that causes illness, hospitalizations, and mortality annually worldwide. IAV is also a zoonotic pathogen with a multitude of hosts, allowing for interspecies transmission, reassortment events, and the emergence of novel pandemics, as was seen in 2009 with the emergence of a swine-origin H1N1 (pdmH1N1) virus into humans, causing the first influenza pandemic of the 21st century. While the 2009 pandemic was considered to have high morbidity and low mortality, studies have linked the pdmH1N1 virus and its gene segments to increased disease in humans and animal models. Genetic components of the pdmH1N1 virus currently circulate in the swine population, reassorting with endemic swine viruses that co-circulate and occasionally spillover into humans. This is evidenced by the regular detection of variant swine IAVs in humans associated with state fairs and other intersections of humans and swine. Defining genetic changes that support species adaptation, virulence, and cross-species transmission, as well as mutations that enhance or attenuate these features, will improve our understanding of influenza biology. It aids in surveillance and virus risk assessment and guides the establishment of counter measures for emerging viruses. Here, we review the current understanding of the determinants of specific IAV phenotypes, focusing on the fitness, transmission, and virulence determinants that have been identified in swine IAVs and/or in relation to the 2009 pdmH1N1 virus.

Evolution of Indian Influenza A (H1N1) Hemagglutinin Strains: A Comparative Analysis of the Pandemic Californian HA Strain

The need for a vaccine/inhibitor design has become inevitable concerning the emerging epidemic and pandemic viral infections, and the recent outbreak of the influenza A (H1N1) virus is one such example. From 2009 to 2018, India faced severe fatalities due to the outbreak of the influenza A (H1N1) virus. In this study, the potential features of reported Indian H1N1 strains are analyzed in comparison with their evolutionarily closest pandemic strain, A/California/04/2009. The focus is laid on one of its surface proteins, hemagglutinin (HA), which imparts a significant role in attacking the host cell surface and its entry. The extensive analysis performed, in comparison with the A/California/04/2009 strain, revealed significant point mutations in all Indian strains reported from 2009 to 2018. Due to these mutations, all Indian strains disclosed altered features at the sequence and structural levels, which are further presumed to be associated with their functional diversity as well. The mutations observed with the 2018 HA sequence such as S91R, S181T, S200P, I312V, K319T, I419M, and E523D might improve the fitness of the virus in a new host and environment. The higher fitness and decreased sequence similarity of mutated strains may compromise therapeutic efficacy. In particular, the mutations observed commonly, such as serine-to-threonine, alanine-to-threonine, and lysine-to-glutamine at various regions, alter the physico-chemical features of receptor-binding domains, N-glycosylation, and epitope-binding sites when compared with the reference strain. Such mutations render diversity among all Indian strains, and the structural and functional characterization of these strains becomes inevitable. In this study, we observed that mutational drift results in the alteration of the receptor-binding domain, the generation of new variant N-glycosylation along with novel epitope-binding sites, and modifications at the structural level. Eventually, the pressing need to develop potentially distinct next-generation therapeutic inhibitors against the HA strains of the Indian influenza A (H1N1) virus is also highlighted here.

Novel coronavirus disease (COVID-19): Emergence, early infection rate, and deployment strategies for preventive solutions

Novel coronavirus commonly known as coronavirus disease 19 (COVID-19) has rapidly spread worldwide and triggered the current global health crisis. It mostly affects humans through the zoonotic transmission of coronavirus 2 (SARS-CoV-2). This chapter focuses on the various epidemics and pandemics (plague, cholera, Spanish flu, etc.) in the history of human civilization, principal component analysis (PCA) for the interpretation of COVID-19 spreading kinetics during the first wave (in the year 2020), the potential use of herbal medicines, dietary remedies, and allopathic therapy to fight COVID-19, and various preventive measures undertaken to combat the pandemic during the first wave. The numbers of confirmed, recovered, active, and deceased cases is considered for the mapping of PCA within different countries. This study can be used as an informative approach for anticipating and strategy-making against COVID-19 or some other pandemics in the ensuing times.

Tetramerizing tGCN4 domain facilitates production of Influenza A H1N1 M2e higher order soluble oligomers that show enhanced immunogenicity in vivo

One strategy for the development of a next generation influenza vaccine centers upon using conserved domains of the virus to induce broader and long-lasting immune responses. The production of artificial proteins by mimicking native-like structures has shown to be a promising approach for vaccine design against diverse enveloped viruses. The amino terminus of influenza A virus matrix 2 ectodomain (M2e) is highly conserved among influenza subtypes, and previous studies have shown M2e-based vaccines are strongly immunogenic, making it an attractive target for further exploration. We hypothesized that stabilizing M2e protein in the mammalian system might influence the immunogenicity of M2e with the added advantage to robustly produce the large scale of proteins with native-like fold and hence can act as an efficient vaccine candidate. In this study, we created an engineered construct in which the amino terminus of M2e is linked to the tetramerizing domain tGCN4, expressed the construct in a mammalian system, and tested for immunogenicity in BALB/c mice. We have also constructed a stand-alone M2e construct (without tGCN4) and compared the protein expressed in mammalian cells and in Escherichia coli using in vitro and in vivo methods. The mammalian-expressed protein was found to be more stable, more antigenic than the E. coli protein, and form higher-order oligomers. In an intramuscular protein priming and boosting regimen in mice, these proteins induced high titers of antibodies and elicited a mixed Th1/Th2 response. These results highlight the mammalian-expressed M2e soluble proteins as a promising vaccine development platform.

Coinfection of H1N1 Influenza and Scrub Typhus-A Review

The H1N1 influenza infection usually coincides with the typical scrub typhus season in North India. This leads to diagnostic difficulties due to their similar and non-specific symptoms. We describe three patients with confirmed co-infection of pandemic (H1N1) influenza and scrub typhus who had presented with acute respiratory distress syndrome. A systematic review of database yielded one case of scrub typhus and H1N1 influenza co-infection reported from South Korea. Co-infection of influenza with tropical infections may not be uncommon in endemic countries and hence a high index of suspicion on the part of physicians coupled with appropriate investigations are needed. The true burden of co-infections needs to be evaluated during outbreaks of influenza in a systematic manner.

COVID-19 pandemic: mental health and beyond - the Indian perspective

India is a de facto continent in the garb of a country. COVID-19 is an unprecedented global pandemic spanning continents. Being the second most populous country in the world, experts regard how India deals with the outbreak will have enormous impact on the world’s ability to deal with it. The country has been in lockdown since March 25, 2020 until the current time of early May 2020, and despite several challenges, there has been early success. The major conflict now is the health benefits weighed up against the deleterious social and economic consequences of prolonged lockdown, that is, life versus livelihood. This unprecedented calamity could potentially cause or exacerbate various psychiatric disorders. It is recognized that lifestyle changes and limited screen time may help reduce mental health difficulties. Considering the physical barriers to consultation, development of telemedicine services is needed. This pandemic, like other previous pandemics, will pass, and until this happens, we must remain extremely vigilant.

Molecular characterization of influenza A(H1N1)pdm09 viruses circulating at various geographical locations in India, 2017

Background & objectives

Influenza virological surveillance is an essential tool for the early detection of novel genetic variants of epidemiologic and clinical significance. This study was aimed to genetically characterize A(H1N1)pdm09 virus circulating in 2017 and to compare it with the global data.

Methods

The regional/State Viral Research and Diagnostic Laboratories (VRDLs) provided influenza diagnosis for referred clinical samples and shared influenza A(H1N1)pdm09 positives with the Indian Council of Medical Research-National Institute of Virology (ICMR-NIV), Pune, India, for hemagglutinin (HA) gene phylogenetic analysis. Sites at Manipal, Jaipur and Dibrugarh performed the sequencing and shared the sequence data for analysis. The antiviral susceptibility of influenza viruses was assessed for known molecular marker H275Y at the ICMR-NIV, Pune.

Results

All the eight VRDLs had well-established influenza diagnostic facilities and showed increased activity of influenza A(H1N1)pdm09 during 2017. Phylogenetic analysis showed that the viruses from the different regions of the country were similar to A/Michigan/45/2015 strain which was the 2017-2018 recommended vaccine strain and were clustered with the globally circulating clade 6B.1 with signature mutations S84N, S162N and I216T. The clade 6B.1 showed further subgrouping with additional mutations S74R, S164T and I295V; however, there was no significant association between the presence of these mutations and severity of disease due to influenza. All the study viruses were sensitive to oseltamivir.

Interpretation & conclusions

During the study period, all the study sites reported globally circulating A/Michigan/45/2015 vaccine strain of influenza A(H1N1)pdm09 viruses and remained sensitive to oseltamivir. Further genetic and antigenic characterization of influenza viruses is recommended to address public health concerns.

Epidemiological and Immunological Features of Influenza Viruses in Hospitalized Children with Influenza Illness in Hangzhou

Objectives: We evaluated the epidemiological features and various inflammatory markers in hospitalized children with influenza virus infection in China. Methods: The real-time RT-PCR assay was performed for detection and genotyping of influenza A and B virus. Th1/Th2 cytokines, WBC, and CRP were determined in influenza virus positive children. Results: H1N1 and Yamagata were the prevalent genotypes of influenza A and B virus in Hangzhou, respectively. IL-2, IL-10, and CRP were significantly increased and IFN-γ was decreased in children with severe Influenza A virus infection, and TNF-α and IFN-γ levels were found to be significantly lower in children with severe Influenza B virus infection. Conclusion: Increased IL-2, IL-10, and CRP with decreased IFN-γ may indicate a severe influenza A virus infection, and decreased TNF-α and IFN-γ may indicate a severe influenza B virus infection in children.

Targeting of Influenza Viral Epitopes to Antigen-Presenting Cells by Genetically Engineered Chimeric Molecules in a Humanized NOD SCID Gamma Transfer Model

Antiviral DNA vaccines are a novel strategy in the vaccine development field, which basically consists of the administration of expression vectors coding viral antigen sequences into the host's cells. Targeting of conserved viral epitopes by antibody fragments specific to activating cell surface co-receptor molecules on antigen-presenting cells could be an alternative approach for inducing protective immunity. It has been shown that FcγRI on human monocytes enhances antigen presentation in vivo. Various DNA constructs, encoding a Single-chain variable antibodies (scFv) from mouse anti-human FcγRI monoclonal antibody, coupled to a sequence encoding a T- and B-cell epitope-containing influenza A virus hemagglutinin inter-subunit peptide were inserted into the eukaryotic expression vector system pTriEx-3 Neo. The constructed chimeric DNA molecules were expressed by transfected Chinese hamster ovary cells and the ability of the engineered proteins to interact with FcγRI-expressing cells was confirmed by flow cytometry. The fusion protein induced a strong signal transduction on human monocytes via FcγRI. The expression vector pTriEx-3 Neo containing the described construct was used as a naked DNA vaccine and introduced directly to experimental humanized NOD SCID gamma mice with or without boosting with the expressed fusion protein. Immunization with the generated DNA chimeric molecules and prime-boost with the expressed recombinant proteins induced significant serum levels of anti-influenza immunoglobulin G antibodies and strong cytotoxic T lymphocyte activity against influenza virus-infected cells in humanized animals.

Genetic variations of the Hemagglutinin gene of Pandemic Influenza A (H1N1) viruses in Assam, India during 2016

Since its emergence in 2009, Influenza A/H1N1pdm09 virus has evolved continuously. Marked genetic variations have occurred in the HA1 domain of the hemagglutinin gene causing the emergence of new variants. The present study genetically characterized the hemagglutinin (HA) gene of Influenza A/H1N1pdm09 strains from Assam circulating in 2016 that caused a mild outbreak without any reported mortality. Sequence analysis of the HA gene of 20 positive Assam/H1N1pdm09 strains revealed 3 mutations (K180Q, S202T, S220T) at the antigenic sites along with several other reported mutations which are in close proximity to the antigenic sites and therefore might affect the viral antigenicity. Phylogenetically, the Assam/H1N1pdm09 strains clustered into genogroup 6B. These genetic variations highlight the importance of continuous surveillance and characterization of Influenza A/H1N1pdm09 virus activity to track the genetic makeup and diversification that may affect the behavior of the virus.

Public Health Policy and Experience of the 2009 H1N1 Influenza Pandemic in Pune, India

BACKGROUND

Prior experience and the persisting threat of influenza pandemic indicate the need for global and local preparedness and public health response capacity. The pandemic of 2009 highlighted the importance of such planning and the value of prior efforts at all levels. Our review of the public health response to this pandemic in Pune, India, considers the challenges of integrating global and national strategies in local programmes and lessons learned for influenza pandemic preparedness.

METHODS

Global, national and local pandemic preparedness and response plans have been reviewed. In-depth interviews were undertaken with district health policy-makers and administrators who coordinated the pandemic response in Pune.

RESULTS

In the absence of a comprehensive district-level pandemic preparedness plan, the response had to be improvised. Media reporting of the influenza pandemic and inaccurate information that was reported at times contributed to anxiety in the general public and to widespread fear and panic. Additional challenges included inadequate public health services and reluctance of private healthcare providers to treat people with flu-like symptoms. Policy-makers developed a response strategy that they referred to as the Pune plan, which relied on powers sanctioned by the Epidemic Act of 1897 and resources made available by the union health ministry, state health department and a government diagnostic laboratory in Pune.

CONCLUSION

The World Health Organization's (WHO's) global strategy for pandemic control focuses on national planning, but state-level and local experience in a large nation like India shows how national planning may be adapted and implemented. The priority of local experience and requirements does not negate the need for higher level planning. It does, however, indicate the importance of local adaptability as an essential feature of the planning process. Experience and the implicit Pune plan that emerged are relevant for pandemic preparedness and other public health emergencies.

Molecular and epidemiological analysis of pandemic and post-pandemic influenza A(H1N1)pdm09 virus from central India

Influenza A(H1N1)pdm09 virus pandemic struck India in 2009 and continues to cause outbreaks in its post-pandemic phase. Diminutive information is available about influenza A(H1N1)pdm09 from central India. This observational study presents epidemiological and molecular findings for the period of 6 years. Throat swab samples referred from districts of Madhya Pradesh were subjected to diagnosis of influenza A(H1N1)pdm09 following WHO guidelines. Clinical and epidemiological data were recorded and analyzed. Hemagglutinin (HA) gene sequencing and phylogenetic analysis were performed. The H275Y mutation responsible for antiviral resistance was tested using allelic real-time RT-PCR. Out of 7365 tested samples, 2406 (32.7%) were positive for influenza A(H1N1)pdm09, of which 363 (15.08%) succumbed to infection. Significant trends were observed in positivity (χ²  = 50.8; P < 0.001) and mortality (χ²  = 24.4; P < 0.001) with increasing age. Mutations having clinical and epidemiological importance were detected. Phylogenetic analysis of HA gene sequences revealed that clade 7, 6A, and 6B viruses were in circulation. Oseltamivir resistance was detected in three fatal cases. Influenza A(H1N1)pdm09 viruses having genetic diversity were detected from central India and continues to be a concern for public health. This study highlights the need of year-round monitoring by establishment of strong molecular and clinical surveillance program.

Possible explanations for why some countries were harder hit by the pandemic influenza virus in 2009 - a global mortality impact modeling study

BACKGROUND

A global pandemic mortality study found prominent regional mortality variations in 2009 for Influenza A(H1N1)pdm09. Our study attempts to identify factors that explain why the pandemic mortality burden was high in some countries and low in others.

METHODS

As a starting point, we identified possible risk factors worth investigating for Influenza A(H1N1)pdm09 mortality through a targeted literature search. We then used a modeling procedure (data simulations and regression models) to identify factors that could explain differences in respiratory mortality due to Influenza A(H1N1)pdm09. We ran sixteen models to produce robust results and draw conclusions. In order to assess the role of each factor in explaining differences in excess pandemic mortality, we calculated the reduction in between country variance, which can be viewed as an effect-size for each factor.

RESULTS

The literature search identified 124 publications and 48 possible risk factors, of which we were able to identify 27 factors with appropriate global datasets. The modelling procedure indicated that age structure (explaining 40% of the mean between country variance), latitude (8%), influenza A and B viruses circulating during the pandemic (3-8%), influenza A and B viruses circulating during the preceding influenza season (2-6%), air pollution (pm10; 4%) and the prevalence of other infections (HIV and TB) (4-6%) were factors that explained differences in mortality around the world. Healthcare expenditure, levels of obesity, the distribution of antivirals, and air travel did not explain global pandemic mortality differences.

CONCLUSIONS

Our study found that countries with a large proportion of young persons had higher pandemic mortality rates in 2009. The co-circulation of influenza viruses during the pandemic and the circulation of influenza viruses during the preceding season were also associated with pandemic mortality rates. We found that real time assessments of 2009 pandemic mortality risk factors (e.g. obesity) probably led to a number of false positive findings.

History and current trends in influenza virus infections with special reference to Sri Lanka

The World Health Organization (WHO) estimates that approximately one billion people are infected and up to 500,000 people die from influenza each year in the world. Influenza is considered to be the greatest killer of the human populations, due to the 1918 Spanish flu, which killed millions around the world. Despite the effective treatment available against influenza, it still contributes to significant morbidity and mortality. Currently circulating influenza strains in humans include influenza A (H1N1)pdm09, influenza A (H3N2) and influenza B viruses, (B/Victoria and B/Yamagata). Influenza has been prevalent in Sri Lanka from 1969, since then it continued to cause morbidity and mortality in children and adults. The current global influenza surveillance network monitors the global influenza activity through WHO collaborating centres. The Medical Research Institute monitors and diagnoses influenza cases in the country as part of the WHO network laboratories. Vaccinations to high risk groups and antiviral therapy for the successful prevention of influenza have been practiced in Sri Lanka. This review highlights the impact of influenza on public health in Sri Lanka including the historical aspects, current diagnostic practices and prevention approaches in high risk individuals in the country.

Synergy between the classical and alternative pathways of complement is essential for conferring effective protection against the pandemic influenza A(H1N1) 2009 virus infection

The pandemic influenza A(H1N1) 2009 virus caused significant morbidity and mortality worldwide thus necessitating the need to understand the host factors that influence its control. Previously, the complement system has been shown to provide protection during the seasonal influenza virus infection, however, the role of individual complement pathways is not yet clear. Here, we have dissected the role of intact complement as well as of its individual activation pathways during the pandemic influenza virus infection using mouse strains deficient in various complement components. We show that the virus infection in C3^-/- mice results in increased viral load and 100% mortality, which can be reversed by adoptive transfer of naïve wild-type (WT) splenocytes, purified splenic B cells, or passive transfer of immune sera from WT, but not C3^-/- mice. Blocking of C3a and/or C5a receptor signaling in WT mice using receptor antagonists and use of C3aR^-/- and C5aR^-/- mice showed significant mortality after blocking/ablation of C3aR, with little or no effect after blocking/ablation of C5aR. Intriguingly, deficiency of C4 and FB in mice resulted in only partial mortality (24%-32%) suggesting a necessary cross-talk between the classical/lectin and alternative pathways for providing effective protection. In vitro virus neutralization experiments performed to probe the cross-talk between the various pathways indicated that activation of the classical and alternative pathways in concert, owing to coating of viral surface by antibodies, is needed for its efficient neutralization. Examination of the virus-specific complement-binding antibodies in virus positive subjects showed that their levels vary among individuals. Together these results indicate that cooperation between the classical and alternative pathways not only result in efficient direct neutralization of the pandemic influenza virus, but also lead to the optimum generation of C3a, which when sensed by the immune cells along with the antigen culminates in generation of effective protective immune responses.

The pandemic influenza A(H1N1) 2009 virus is now circulating seasonally and causing a significant disease burden worldwide. Hence, it is important to delineate the immune components required for protection against its infection. Here we demonstrate that presence of intact complement is essential for clearing the pandemic influenza virus infection, wherein complement synthesized by B cells plays a major role. Further, we show that activation of the classical as well as alternative pathways is a requisite for efficient neutralization of the virus as well as the optimum generation of C3a, which is necessary for boosting the protective immune responses. Our results thus reveal that deficiencies of components of the classical and alternative pathways enhance the susceptibility to and severity of the pandemic influenza virus infection.

Policy perspectives on post pandemic influenza vaccination in Ghana and Malawi

BACKGROUND

In the late 1990s, in the context of renewed concerns of an influenza pandemic, countries such as Ghana and Malawi established plans for the deployment of vaccines and vaccination strategies. A new pandemic was declared in mid-June 2009, and by April 2011, Ghana and Malawi vaccinated 10% of the population. We examine the public health policy perspectives on vaccination as a means to prevent the spread of infection under post pandemic conditions.

METHODS

In-depth interviews were conducted with 46 policymakers (Ghana, n = 24; Malawi, n = 22), identified through snowballing sampling. Interviews were supplemented by field notes and the analysis of policy documents.

RESULTS

The use of vaccination to interrupt the pandemic influenza was affected by delays in the procurement, delivery and administration of vaccines, suboptimal vaccination coverage, refusals to be vaccinated, and the politics behind vaccination strategies. More generally, rolling-out of vaccination after the transmission of the influenza virus had abated was influenced by policymakers' own financial incentives, and government and foreign policy conditionality on vaccination. This led to confusion about targeting and coverage, with many policymakers justifying that the vaccination of 10% of the population would establish herd immunity and so reduce future risk. Ghana succeeded in vaccinating 2.3 million of the select groups (100% coverage), while Malawi, despite recourse to force, succeeded only in vaccinating 1.15 million (74% coverage of select groups). For most policymakers, vaccination coverage was perceived as successful, despite that vaccination delays and coverage would not have prevented infection when influenza was at its peak.

CONCLUSIONS

While the vaccination strategy was problematic and implemented too late to reduce the effects of the 2009 epidemic, policy makers supported the overall goal of pandemic influenza vaccination to interrupt infection. In this context, there was strong support for governments engaging in contracts with pharmaceutical companies to ensure the timely supply of vaccines, and developing well-defined guidelines to address vaccination delays, refusals and coverage.

Genetic Characterization of Circulating 2015 A(H1N1)pdm09 Influenza Viruses from Eastern India

In 2015, the swine derived A(H1N1)pdm09 pandemic strain outbreak became widespread throughout the different states of India. The reported cases and deaths in 2015 surpassed the previous years with more than 39000 laboratory confirmed cases and a death toll of more than 2500 people. There are relatively limited complete genetic sequences available for this virus from Asian countries. In this study, we describe the full genome analysis of influenza 2015 A(H1N1)pdm09 viruses isolated from West Bengal between January through December 2015. The phylogenetic analysis of the haemagglutinin sequence revealed clustering with globally circulating strains of genogroup 6B. This was further confirmed by the constructed concatenated tree using all eight complete gene segments of Kolkata A(H1N1)pdm09 isolates with the other strains from different timeline and lineages. A study from Massachusetts Institute of Technology (MIT) in 2015 reported novel mutations T200A and D225N in haemagglutinin gene of a 2014 Indian strain (A/India/6427/2014). However, in all the pandemic strains of 2014-2015 reported from India, so far including A(H1N1)pdm09 strains from Kolkata, D225N mutation was not observed, though the T200A mutation was found to be conserved. Neuraminidase gene of the analyzed strains did not show any oseltamivir resistant mutation H275Y suggesting continuation of Tamiflu® as drug of choice. The amino acid sequences of the all gene segments from 2015 A(H1N1)pdm09 isolates identified several new mutations compared to the 2009 A(H1N1)pdm09 strains, which may have contributed towards enhanced virulence, compared to 2009 A(H1N1)pdm09 strains.

Community awareness, use and preference for pandemic influenza vaccines in Pune, India

Vaccination is a cornerstone of influenza prevention, but limited vaccine uptake was a problem worldwide during the 2009–2010 pandemic. Community acceptance of a vaccine is a critical determinant of its effectiveness, but studies have been confined to high-income countries. We conducted a cross-sectional, mixed-method study in urban and rural Pune, India in 2012–2013. Semi-structured explanatory model interviews were administered to community residents (n = 436) to study awareness, experience and preference between available vaccines for pandemic influenza. Focus group discussions and in-depth interviews complemented the survey. Awareness of pandemic influenza vaccines was low (25%). Some respondents did not consider vaccines relevant for adults, but nearly all (94.7%), when asked, believed that a vaccine would prevent swine flu. Reported vaccine uptake however was 8.3%. Main themes identified as reasons for uptake were having heard of a death from swine flu, health care provider recommendation or affiliation with the health system, influence of peers and information from media. Reasons for non-use were low perceived personal risk, problems with access and cost, inadequate information and a perceived lack of a government mandate endorsing influenza vaccines. A majority indicated a preference for injectable over nasal vaccines, especially in remote rural areas. Hesitancy from a lack of confidence in pandemic influenza vaccines appears to have been less of an issue than access, complacency and other sociocultural considerations. Recent influenza outbreaks in 2015 highlight a need to reconsider policy for routine influenza vaccination while paying attention to sociocultural factors and community preferences for effective vaccine action.

Epidemiology of influenza viruses from 2009 to 2013 - A sentinel surveillance report from Union territory of Puducherry, India

OBJECTIVE

To report the findings of influenza surveillance programme from Union territory of Puducherry and to document the clinical and epidemiological data of influenza viruses over a five year period from 2009 to 2013.

METHODS

Respiratory samples were collected from patients with influenza-like illness from 2009 to 2013 as part of routine diagnostic and surveillance activity. Detection of pandemic influenza A (H1N1) 2009, influenza A (H3N2) and influenza B was done using Real-time PCR.

RESULTS

Of the total 2247 samples collected from patients with influenza-like illness during the study period 287 (12.7%) and 92 (4.0%) were positive for influenza A (H1N1) 2009 and influenza A (H3N2) respectively. A subset of 557 of these samples were also tested for influenza B and 24 (4.3%) were positive. Significantly higher positivity rate for both viruses was observed in adults when compared with children. The peak positivity of influenza A (H1N1) 2009 was observed in 2009 followed by 2012, while that of influenza A (H3N2) was more uniformly distributed with the exception of 2012. Overall mortality rate due to influenza A (H1N1) 2009 was 7.6% while it was 1% for influenza A (H3N2). Each year influenza-like illness and influenza virus activity coincided with period of high rainfall and low temperature except in the first half of 2012.

CONCLUSIONS

As the sole referral laboratory in this region, the data provides a comprehensive picture of influenza activity. This information will be useful in future planning of the vaccine schedule and influenza pandemic preparedness.

Dynamics of influenza seasonality at sub-regional levels in India and implications for vaccination timing

BACKGROUND

Influenza surveillance is an important tool to identify emerging/reemerging strains, and defining seasonality. We describe the distinct patterns of circulating strains of the virus in different areas in India from 2009 to 2013.

METHODS

Patients in ten cities presenting with influenza like illness in out-patient departments of dispensaries/hospitals and hospitalized patients with severe acute respiratory infections were enrolled. Nasopharangeal swabs were tested for influenza viruses by real-time RT-PCR, and subtyping; antigenic and genetic analysis were carried out using standard assays.

RESULTS

Of the 44,127 ILI/SARI cases, 6,193 (14.0%) were positive for influenza virus. Peaks of influenza were observed during July-September coinciding with monsoon in cities Delhi and Lucknow (north), Pune (west), Allaphuza (southwest), Nagpur (central), Kolkata (east) and Dibrugarh (northeast), whereas Chennai and Vellore (southeast) revealed peaks in October-November, coinciding with the monsoon months in these cities. In Srinagar (Northern most city at 34°N latitude) influenza circulation peaked in January-March in winter months. The patterns of circulating strains varied over the years: whereas A/H1N1pdm09 and type B co-circulated in 2009 and 2010, H3N2 was the predominant circulating strain in 2011, followed by circulation of A/H1N1pdm09 and influenza B in 2012 and return of A/H3N2 in 2013. Antigenic analysis revealed that most circulating viruses were close to vaccine selected viral strains.

CONCLUSIONS

Our data shows that India, though physically located in northern hemisphere, has distinct seasonality that might be related to latitude and environmental factors. While cities with temperate seasonality will benefit from vaccination in September-October, cities with peaks in the monsoon season in July-September will benefit from vaccination in April-May. Continued surveillance is critical to understand regional differences in influenza seasonality at regional and sub-regional level, especially in countries with large latitude span.

Genetic changes in influenza A(H3N2) viruses circulating during 2011 to 2013 in northern India (Lucknow)

Genetic variability in the hemagglutinin (HA1) and the neuraminidase (NA) genes of influenza viruses results in the emergence of new strains which differ in pathogenicity and severity. The present study was undertaken for genotypic characterization of the HA1 and NA genes of the influenza A(H3N2) strains, detected during the 2011-2013. A total of fifty five influenza A(H3N2) positive samples [2011 (n = 20), 2012 (n = 4) and 2013 (n = 31)] were studied. The 824 bp segment of HA1 gene and 931 bp segment of NA gene were amplified and sequenced by Big-Dye terminator kit on ABI3130, Genetic analyzer. Molecular and phylogenetic analysis was done by MEGA 5.05 software and PhyML program (v3.0). Mutations were determined by comparing the deduced amino acid sequences of study strains with that of 2009-2013 vaccine strains. The studied influenza A(H3N2) strains showed 98.1-99.6% similarity in HA1 and NA amino acid sequences with the influenza A/Victoria/361/2011 vaccine strain. Four mutations in the HA1 amino acid sequences (T128A, R142G, L157S and N278K) and three unique mutations in the NA amino acid sequences [D251V, S315G and V313A] were found. These mutations were observed only in strains from the year 2013 (cluster II). None of the strains showed the presence of mutations, N294S and R292K, markers of oseltamivir resistance. In conclusion, Lucknow strains have accumulated the significant number of mutations in the antigenic sites of the HA and the NA coding sequences and continue to be evolving from the 2013 vaccine strain [A/Victoria/361/2011], however, mutations specific for oseltamivir resistance were not detected.

Cultural epidemiology of pandemic influenza in urban and rural Pune, India: a cross-sectional, mixed-methods study

OBJECTIVE

To identify and compare sociocultural features of pandemic influenza with reference to illness-related experience, meaning and behaviour in urban and rural areas of India.

DESIGN

Cross-sectional, mixed-methods, cultural epidemiological survey with vignette-based interviews. Semistructured explanatory model interviews were used to study community ideas of the 2009 influenza pandemic. In-depth interviews elaborated respondents' experience during the pandemic.

SETTING

Urban and rural communities, Pune district, western India.

PARTICIPANTS

Survey of urban (n=215) and rural (n=221) residents aged between 18 and 65 years. In-depth interviews of respondents with a history of 2009 pandemic influenza (n=6).

RESULTS

More urban (36.7%) than rural respondents (16.3%, p<0.001) identified the illness in the vignette as 'swine flu'. Over half (56.7%) believed the illness would be fatal without treatment, but with treatment 96% predicted full recovery. Worry ('tension') about the illness was reported as more troubling than somatic symptoms. The most common perceived causes-'exposure to a dirty environment' and 'cough or sneeze of an infected person'-were more prominent in the urban group. Among rural respondents, climatic conditions, drinking contaminated water, tension and cultural ideas on humoral imbalance from heat-producing or cold-producing foods were more prominent. The most widely reported home treatment was herbal remedies; more rural respondents suggested reliance on prayer, and symptom relief was more of a priority for urban respondents. Government health services were preferred in the urban communities, and rural residents relied more than urban residents on private facilities. The important preventive measures emphasised were cleanliness, wholesome lifestyle and vaccines, and more urban respondents reported the use of masks. In-depth interviews indicated treatment delays during the 2009 pandemic, especially among rural patients.

CONCLUSIONS

Although the term was well known, better recognition of pandemic influenza cases is needed, especially in rural areas. Improved awareness, access to treatment and timely referrals by private practitioners are also required to reduce treatment delays.

Optimizing the precision of case fatality ratio estimates under the surveillance pyramid approach

In the management of emerging infectious disease epidemics, precise and accurate estimation of severity indices, such as the probability of death after developing symptoms—the symptomatic case fatality ratio (sCFR)—is essential. Estimation of the sCFR may require merging data gathered through different surveillance systems and surveys. Since different surveillance strategies provide different levels of precision and accuracy, there is need for a theory to help investigators select the strategy that maximizes these properties. Here, we study the precision of sCFR estimators that combine data from several levels of the severity pyramid. We derive a formula for the standard error, which helps us find the estimator with the best precision given fixed resources. We further propose rules of thumb for guiding the choice of strategy: For example, should surveillance of a particular severity level be started? Which level should be preferred? We derive a formula for the optimal allocation of resources between chosen surveillance levels and provide a simple approximation that can be used in thinking more heuristically about planning surveillance. We illustrate these concepts with numerical examples corresponding to 3 influenza pandemic scenarios. Finally, we review the equally important issue of accuracy.

Developing and validating a tablet version of an illness explanatory model interview for a public health survey in Pune, India

BACKGROUND

Mobile electronic devices are replacing paper-based instruments and questionnaires for epidemiological and public health research. The elimination of a data-entry step after an interview is a notable advantage over paper, saving investigator time, decreasing the time lags in managing and analyzing data, and potentially improving the data quality by removing the error-prone data-entry step. Research has not yet provided adequate evidence, however, to substantiate the claim of fewer errors for computerized interviews.

METHODOLOGY

We developed an Android-based illness explanatory interview for influenza vaccine acceptance and tested the instrument in a field study in Pune, India, for feasibility and acceptability. Error rates for tablet and paper were compared with reference to the voice recording of the interview as gold standard to assess discrepancies. We also examined the preference of interviewers for the classical paper-based or the electronic version of the interview and compared the costs of research with both data collection devices.

RESULTS

In 95 interviews with household respondents, total error rates with paper and tablet devices were nearly the same (2.01% and 1.99% respectively). Most interviewers indicated no preference for a particular device; but those with a preference opted for tablets. The initial investment in tablet-based interviews was higher compared to paper, while the recurring costs per interview were lower with the use of tablets.

CONCLUSION

An Android-based tablet version of a complex interview was developed and successfully validated. Advantages were not compromised by increased errors, and field research assistants with a preference preferred the Android device. Use of tablets may be more costly than paper for small samples and less costly for large studies.

Homeopathic treatment of patients with influenza-like illness during the 2009 A/H1N1 influenza pandemic in India

INTRODUCTION

We conducted a prospective, multi-centre, data collection survey of homeopathic practice in treatment of influenza-like illness in India during the 2009 pandemic of A/H1N1 influenza ('swine flu', SF).

AIMS

To survey the practice of homeopathic practitioners in India in the management of SF, with respect to: (a) patients' symptoms at presentation and at follow-up (FU) consultation; (b) homeopathic medicines prescribed.

METHODS

Data collection took place from October 2009 to February 2010, at the peak of the pandemic. All patients satisfying the minimum diagnostic symptoms of SF were eligible for inclusion. Data per appointment (in person or by telephone) were recorded by practitioners in spreadsheet format. All records were anonymised and included: whether patient was immunised against A/H1N1; influenza symptoms at consultation; the homeopathic medicine/s prescribed; whether antiviral medicine prescribed.

RESULTS

Twenty-three homeopathic physicians contributed to data collection. At the first appointment, 1126 patients had valid SF symptoms. A total of 89 different combinations of SF symptoms was observed, the most common being temperature >38°C + cough + runny nose (n = 170; 15.1%). A total of 44 different remedies (or combinations of remedies) were used at these first appointments, the most frequently prescribed being Arsenicum album (n = 265; 23.5%). For a total of 99 FU appointments with valid SF symptoms, Arsenicum album was prescribed most frequently overall (n = 28; 28.0%).

CONCLUSIONS

In our sample, the 2009 A/H1N1 influenza pandemic in India was characterised by several prominent symptoms and symptom/medicine associations, particularly temperature >38°C + cough + runny nose, associated with Arsenicum album. Future studies should collect additional keynote prescribing symptoms that influence the choice of homeopathic medicine.

Case fatality risk of influenza A (H1N1pdm09): a systematic review

BACKGROUND

During the 2009 influenza pandemic, uncertainty surrounding the seriousness of human infections with the H1N1pdm09 virus hindered appropriate public health response. One measure of seriousness is the case fatality risk, defined as the probability of mortality among people classified as cases.

METHODS

We conducted a systematic review to summarize published estimates of the case fatality risk of the pandemic influenza H1N1pdm09 virus. Only studies that reported population-based estimates were included.

RESULTS

We included 77 estimates of the case fatality risk from 50 published studies, about one-third of which were published within the first 9 months of the pandemic. We identified very substantial heterogeneity in published estimates, ranging from less than 1 to more than 10,000 deaths per 100,000 cases or infections. The choice of case definition in the denominator accounted for substantial heterogeneity, with the higher estimates based on laboratory-confirmed cases (point estimates = 0-13,500 per 100,000 cases) compared with symptomatic cases (point estimates = 0-1,200 per 100,000 cases) or infections (point estimates = 1-10 per 100,000 infections). Risk based on symptomatic cases increased substantially with age.

CONCLUSIONS

Our review highlights the difficulty in estimating the seriousness of infection with a novel influenza virus using the case fatality risk. In addition, substantial variability in age-specific estimates complicates the interpretation of the overall case fatality risk and comparisons among populations. A consensus is needed on how to define and measure the seriousness of infection before the next pandemic.

Effectiveness of an Indian-made attenuated influenza A(H1N1)pdm 2009 vaccine: a case control study

A live attenuated influenza A(H1N1)pdm 2009 vaccine was developed and distributed in India in 2010. We estimated the vaccine effectiveness (VE) against laboratory-confirmed pandemic H1N1 (pH1N1) infections in patients with influenza-like illness who visited five tertiary care hospitals in Pune, India during June-December 2010. Swab specimens were analyzed for influenza pH1N1 by reverse transcriptase polymerase chain reaction (RT-PCR). VE was estimated using the test-negative case-control study design and logistic regression. A total of 784 patients (253 cases, 531 controls) were analyzed. The unadjusted overall VE was 75.5% (95% confidence interval [CI] 42.1-89.7), while the adjusted VE was 76% (95% CI 42.1-89.7). We conclude that the live attenuated influenza A(H1N1)pdm 2009 vaccine was effective in our study population, which has opened prospects for using this platform for trivalent formulations.

Pandemic influenza: Experience in a flu OPD of a tertiary care hospital

BACKGROUND

In April 2009, Mexican health authorities announced an outbreak of a novel H1N1 influenza virus, which subsequently caused a pandemic. The world is now moving into the post-pandemic period. The experience gained in handling this pandemic at various levels under different settings has provided us many lessons for the future.

OBJECTIVE

To study the profile of various activities undertaken at flu screening centre as a response to pandemic influenza in a tertiary care hospital.

METHODS

Record-based study conducted in a tertiary care hospital of Pune. Required data was collected from records of flu OPD, ward and local health authority and interviewing related staff. Study included data from October 2009 to October 2010.

RESULTS

A total of 8020 people presenting with influenza like illness (ILI) were screened in the flu OPD under study. Out of these, only 388 (4.84%) met clinical criteria where throat samples were collected, out of which only 81 were found to be positive (20.88%). Total three fatalities (3.7%) occurred out of 81 who had tested positive. Most cases of flu were managed at home (76.54%) while only 19 (23.4%) lab confirmed cases of H1N1 required hospitalisation.

CONCLUSION

Majority of cases of H1N1 (2009) were managed at home. Early diagnosis, quick initiation of treatment, infection control measures, and good care at the hospital can effectively reduce morbidity and mortality in H1N1 pandemic.

Clinical differences between influenza A (H1N1) pdm09 & influenza B infections identified through active community surveillance in North India

BACKGROUND & OBJECTIVES

Most studies on the clinical presentation with influenza viruses have been conducted in outpatient or inpatient medical facilities with only a few studies in community settings. Clinical differences between influenza A (H1N1) pdm 09 and influenza B virus infections have importance for community-based public health surveillance. An active community surveillance at the time of emergence of pandemic influenza provided us with an opportunity to compare the clinical features among patients infected with influenza A (H1N1) pdm09 virus and those with influenza B virus co-circulating in an active community-based weekly surveillance in three villages in Faridabad, Haryana, north India.

METHODS

Active surveillance for febrile acute respiratory infection (FARI) was carried out in a rural community (n=16,182) in the context of an inactivated trivalent influenza vaccine trial (among children <11 yr). Individuals with FARI were assessed clinically by nurses and respiratory samples collected and tested for influenza viruses by real time RT-PCR from November 2009 to August 2010. Clinical symptoms of patients with influenza A (H1N1) pdm 09 and influenza B infection were compared.

RESULTS

Of the 4796 samples tested, 822 (17%) were positive for influenza virus. Of these, 443 (54%) were influenza A (H1N1) pdm09, 373 (45%) were influenza B and six were other subtypes/mixed infections. The mean age was lower for patients with influenza B (16.4 yr) than influenza A (H1N1) pdm09 infection (18.7 yr; P=0.04). Among children aged 5-18 yr, chills/rigours (OR 4.0; CI 2.2, 7.4), sore throat (OR 6.8; CI 2.3, 27.3) and headache (OR2.0; CI 1.3, 3.3) were more common in influenza A (H1N1) pdm09 infection than in influenza B cases. Chills/rigours (OR 2.4; CI 1.4, 4.0) and headache (OR 1.7; CI 1.0, 2.7) were associated with influenza A (H1N1) pdm09 infection in those >18 yr. No significant differences were seen in children <5 yr.

CONCLUSION

Our findings show that the differences in the clinical presentation of influenza A(H1N1)pdm09 and influenza B infections are not likely to be of clinical or public health significance.

A post-marketing surveillance study of a human live-virus pandemic influenza A (H1N1) vaccine (Nasovac (®) ) in India

A live attenuated pandemic H1N1 influenza vaccine was developed in India. A post marketing surveillance was conducted retrospectively in healthy individuals (³ 3 years) who were vaccinated intranasally around one year before. After consent, the subjects recorded adverse events developing within 42 days. Among 7565 individuals (3 - 85 years), a total of 81 solicited adverse reactions (1%) were reported in 49 subjects (0.65%). The reactions included mild to moderate respiratory symptoms. No H1N1 case was encountered during one year postvaccination. The data show the safety of the live attenuated influenza vaccine platform developed in India.

Burden of seasonal and pandemic influenza-associated hospitalization during and after 2009 A(H1N1)pdm09 pandemic in a rural community in India

BACKGROUND

Influenza is vaccine-preventable; however, the burden of severe influenza in India remains unknown. We conducted a population-based study to estimate the incidence of laboratory confirmed influenza-associated hospitalizations in a rural community in western India.

METHODS

We conducted active surveillance for hospitalized patients with acute medical illnesses or acute chronic disease exacerbations in Pune during pandemic and post pandemic periods (May 2009-April 2011). Nasal and throat swabs were tested for influenza viruses. A community health utilization survey estimated the proportion of residents hospitalized with respiratory illness at non-study facilities and was used to adjust incidence estimates from facility-based surveillance.

RESULTS

Among 9,426 hospitalizations, 3,391 (36%) patients were enrolled; 665 of 3,179 (20.9%) tested positive for influenza. Of 665 influenza positives, 340 (51%) were pandemic A(H1N1)pdm09 and 327 (49%) were seasonal, including A/H3 (16%), A/H1 (3%) and influenza B (30%). The proportion of patients with influenza peaked during August 2009 (39%) and 2010 (42%). The adjusted annual incidence of influenza hospitalizations was 46.8/10,000 during pandemic and 40.5/10,000 during post-pandemic period with comparable incidence of A(H1N1)pdm09 during both periods (18.8 and 20.3, respectively). The incidence of both pH1N1 and seasonal hospitalized influenza disease was highest in the 5-29 year olds.

CONCLUSIONS

We document the previously unrecognized burden of influenza hospitalization in a rural community following the emergence of influenza A(H1N1)pdm09 viruses in India. During peak periods of influenza activity circulation i.e during the monsoon period, 20% of all hospital admissions in the community had influenza positivity. These findings can inform development of influenza prevention and control strategies in India.

Socioeconomic, cultural and behavioural features of prior and anticipated influenza vaccine uptake in urban and rural Pune district, India: a mixed-methods case study

INTRODUCTION

Ensuring production capacity of efficacious vaccines for pandemic preparedness alone may not be sufficient for effective influenza control. Community willingness to accept the vaccine is also critical. Population acceptance must therefore be recognised as a major determinant of vaccine effectiveness, and the social, cultural and economic determinants of population acceptance require study for effective policy and action. Pune is a focus of pandemic influenza in India. The experience of the 2009/2010 pandemic in Pune, capacity for vaccine production and experience with vaccine use provide a unique opportunity to address key questions about an effective vaccine intervention strategy for influenza control in India. This study will examine the socioeconomic, cultural and behavioural determinants of anticipated acceptance of influenza vaccines among the urban and rural populations of Pune district. Additionally, community ideas about seasonal influenza and its distinction from pandemic influenza will be investigated. Proposed research also considers the influence of health professionals, policy makers and media professionals on the awareness, preference and use of influenza vaccines.

METHODS AND ANALYSIS

This is a mixed-methods study including urban and rural community surveys, in-depth interviews with health professionals, case studies at two hospitals where suspected influenza cases were referred during the pandemic and in-depth interviews with media professionals and public health policy makers.

ETHICS AND DISSEMINATION

This protocol was approved by the ethics review committees of the Maharashtra Association of Anthropological Sciences and the WHO, and by the Ethics Commission of Basel, Switzerland. The proposed research will provide a better understanding of communication and education needs for vaccine action for influenza control in India and other low-income and middle-income countries. The findings and the approach for health social science research will have implications for containment of pandemic influenza in other settings and for effective vaccine action planning for other vaccines.

Clinical and molecular characteristics of the 2009 pandemic influenza H1N1 infection with severe or fatal disease from 2009 to 2011 in Shenzhen, China

In the past 3 years, the 2009 pandemic influenza virus H1N1 (pH1N1) has led to many severe or fatal cases. The virus-related factors that cause severe or fatal disease are not clear. The clinical and molecular characteristics of pH1N1 infections with severe or fatal disease were examined to understand the correlation between pH1N1 infection and disease severity. Since 2009, three pH1N1 influenza epidemic outbreaks have occurred in Shenzhen, China. One hundred forty-six severe cases were confirmed in the first wave in 2009. In severe cases, a high proportion (49.3%) of patents displayed high fever (>39.0°C), and 73.2% of patients had pneumonia and tracheobronchitis. Seven fatal cases were recorded: three with viral encephalitis and four with respiratory failure. The results of sequencing and phylogenetic analysis showed that the viruses from fatal or severe cases were scattered throughout the phylogenetic tree. Four substitutions (D222G, D222N, D222E, and Q223R) were observed on the 220-loop of the receptor-binding sites of the HA gene. Both D222G and D222N were associated statistically with severe disease. The 2011 viruses had evolved into two distinct branches. Ten specific point mutations occurred in the 2011 virus. In summary, high fever, lower respiratory tract infections and serious complications were the main features of severe cases. Gene variation seemed not to be the main reason for severe disease. Vaccination is the effective mean to prevent infection and severe disease.

Clinical Profile and Predictors of Mortality of Severe Pandemic (H1N1) 2009 Virus Infection Needing Intensive Care: A Multi-Centre Prospective Study from South India

BACKGROUND

This multi-center study from India details the profile and outcomes of patients admitted to the intensive care unit (ICU) with pandemic Influenza A (H1N1) 2009 virus [P(H1N1)2009v] infection.

MATERIALS AND METHODS

Over 4 months, adult patients diagnosed to have P(H1N1)2009v infection by real-time RT-PCR of respiratory specimens and requiring ICU admission were followed up until death or hospital discharge. Sequential organ failure assessment (SOFA) scores were calculated daily.

RESULTS

Of the 1902 patients screened, 464 (24.4%) tested positive for P(H1N1)2009v; 106 (22.8%) patients aged 35±11.9 (mean±SD) years required ICU admission 5.8±2.7 days after onset of illness. Common symptoms were fever (96.2%), cough (88.7%), and breathlessness (85.9%). The admission APACHE-II and SOFA scores were 14.4±6.5 and 5.5±3.1, respectively. Ninety-six (90.6%) patients required ventilation for 10.1±7.5 days. Of these, 34/96 (35.4%) were non-invasively ventilated; 16/34 were weaned successfully whilst 18/34 required intubation. Sixteen patients (15.1%) needed dialysis. The duration of hospitalization was 14.0±8.0 days. Hospital mortality was 49%. Mortality in pregnant/puerperal women was 52.6% (10/19). Patients requiring invasive ventilation at admission had a higher mortality than those managed with non-invasive ventilation and those not requiring ventilation (44/62 vs. 8/44, P<0.001). Need for dialysis was independently associated with mortality (P=0.019). Although admission APACHE-II and SOFA scores were significantly (P<0.02) higher in non-survivors compared with survivors on univariate analysis, individually, neither were predictive on multivariate analysis.

CONCLUSIONS

In our setting, a high mortality was observed in patients admitted to ICU with severe P(H1N1)2009v infection. The need for invasive ventilation and dialysis were associated with a poor outcome.

Performance of case definitions used for influenza surveillance among hospitalized patients in a rural area of India

OBJECTIVE

To assess case definitions for influenza in a rural community in India.

METHODS

Residents of the study area who were hospitalized for any acute medical condition for at least one night between May 2009 and April 2011 were enrolled. Respiratory specimens were collected and tested for influenza viruses in a reverse-transcription polymerase chain reaction (PCR). The PCR results were taken as the "gold standard" in evaluating the performance of several case definitions.

FINDINGS

Of the 3179 patients included in the final analysis, 21% (665) were PCR-positive for influenza virus, 96% reported fever and 4% reported shortness of breath. The World Health Organization (WHO) case definition for severe acute respiratory illness had a sensitivity of 11% among patients aged < 5 years and of 3% among older patients. When shortness of breath was excluded from the definition, sensitivities increased (to 69% and 70%, respectively) and corresponding specificities of 43% and 53% were recorded. Among patients aged ≥ 5 years, WHO's definition of a case of influenza-like illness had a sensitivity of 70% and a specificity of 53%. The addition of "cough and reported or measured fever" increased sensitivity to 80% but decreased specificity to 42%.

CONCLUSION

The inclusion of shortness of breath in WHO's case definition for severe acute respiratory illness may grossly underestimate the burden posed by influenza in hospitals. The exclusion of shortness of breath from this definition or, alternatively, the inclusion of "cough and measured or reported fever" may improve estimates of the burden.

Antibody persistence after Pandemic H1N1 2009 influenza vaccination among healthcare workers in Pune, India

The healthcare workers having seroprotection at 3 weeks (n = 127) following Pandemic H1N1 2009 influenza vaccination were followed up for antibody persistence. Seroprotection at 12 mo (60.2%) was significantly lower as compared with 3 weeks (74.7%), 3 mo (77.8%) and 6 mo (75.4%). The vaccine provided seroprotection up to one year.

Estimation of the burden of pandemic(H1N1)2009 in developing countries: experience from a tertiary care center in South India

Background

The burden of the pandemic (H1N1) 2009 influenza might be underestimated if detection of the virus is mandated to diagnose infection. Using an alternate approach, we propose that a much higher pandemic burden was experienced in our institution.

Methodology/Principal Findings

Consecutive patients (n = 2588) presenting to our hospital with influenza like illness (ILI) or severe acute respiratory infection (SARI) during a 1-year period (May 2009–April 2010) were prospectively recruited and tested for influenza A by real-time RT-PCR. Analysis of weekly trends showed an 11-fold increase in patients presenting with ILI/SARI during the peak pandemic period when compared with the pre-pandemic period and a significant (P<0.001) increase in SARI admissions during the pandemic period (30±15.9 admissions/week) when compared with pre-pandemic (7±2.5) and post-pandemic periods (5±3.8). However, Influenza A was detected in less than one-third of patients with ILI/SARI [699 (27.0%)]; a majority of these (557/699, 79.7%) were Pandemic (H1N1)2009 virus [A/H1N1/09]. An A/H1N1/09 positive test was correlated with shorter symptom duration prior to presentation (p = 0.03). More ILI cases tested positive for A/H1N1/09 when compared with SARI (27.4% vs. 14.6%, P = 0.037). When the entire study population was considered, A/H1N1/09 positivity was associated with lower risk of hospitalization (p<0.0001) and ICU admission (p = 0.013) suggesting mild self-limiting illness in a majority.

Conclusion/Significance

Analysis of weekly trends of ILI/SARI suggest a higher burden of the pandemic attributable to A/H1N1/09 than estimates assessed by a positive PCR test alone. The study highlights methodological consideration in the estimation of burden of pandemic influenza in developing countries using hospital-based data that may help assess the impact of future outbreaks of respiratory illnesses.

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.

Influenza surveillance from November 2008 to 2011; including pandemic influenza A(H1N1)pdm09 in Bhutan

Objective  Describe the influenza A(H1N1) pandemic in Bhutan.

Design  Observational study from sentinel surveillance sites.

Setting  Bhutan remains isolated, with only one to two flights a day at the lone airport, no trains, and only three major roads that enter from India.

Main outcome measures  PCR positive human respiratory samples

Results  The first case of A(H1N1)pdm09 infection was detected in Bhutan in July 2009, 3 months after the virus was first reported in Mexico in April 2009. During the official WHO pandemic period (11 June 2009 to 8 August 2010), a total of 2149 samples were collected and tested by RT‐PCR of which 22.7% (487) were confirmed A(H1N1)pdm09; H3N2, H1N1, and B were positive in 2.2%, 1.1%, and 7.2%, respectively. The highest rate of A(H1N1)pdm09 cases (57.4%) was detected in the 6‐20 year‐old age group. Importantly, Bhutan increased from 3 sentinel sites in April 2009 to 11 a year later, and in April 2010 established PCR capability for influenza.

Conclusions  Despite relative isolation, the A(H1N1)pdm09 reached Bhutan within 3 months of identification in Mexico. The H1N1 pandemic has made Bhutan more prepared for epidemics in the future.

Pathologic study of pandemic influenza A (H1N1) 2009 cases from India

The pandemic influenza A (H1N1) 2009 originated in Mexico and rapidly spread to the United States and many other countries. India reported the first pandemic influenza case in May 2009. Autopsy studies describing the pathology of pandemic influenza infection in humans have appeared in the literature and most of these were from Western countries. We present the clinicopathologic features in 46 fatal cases with confirmed pandemic influenza A (H1N1) 2009 virus infection during August 2009 to October 2010. Postmortem needle biopsy tissues were examined for histopathological changes and distribution of virus antigen by immunohistochemistry. The results are comparable with previous autopsy studies. Diffuse alveolar damage was the consistent finding in the lung tissues. However, underlying medical conditions were not noted in the cases from present study. Consistent presence of viral antigen was noted in the bronchiolar epithelium without any reference to the duration of illness. This study also emphasizes the use of the postmortem needle biopsy technique whenever an autopsy is not possible.

Pandemic Influenza A H1N1 (2009) Virus: Lessons from the Past and Implications for the Future

The recent pandemic by novel influenza A (H1N1) 2009 (pH1N1) virus is an emerging viral infection, being of significant international concern and requires intensive research. The virus spread in pandemic proportions, and continues to be in the post-pandemic phase. Since, the pH1N1 is still circulating in the community, monitoring is required during the post-pandemic period. The pH1N1 defied influenza seasonality and rapidly became dominant over the seasonal influenza viruses. This new strain was antigenically different from the seasonal H1N1 influenza strains due to the genetic re-assortment. Surprisingly, this new reassortant virus emerged at the end of influenza season, caused a sudden toll of mild illness and is now co-circulating with the seasonal strains. The recent outbreak of pH1N1 consolidates the fact that a new reassortant virus may have originated in animal reservoirs and got transferred to human who were in close contact with these animals. There is a continued need for multisite surveillance to detect potentially dangerous influenza strains, which may emerge and establish themselves in human population. This review is an attempt to address the lessons learnt from the recent influenza pandemic and the future implications for prevention and control of influenza.