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

Conducting community-based pediatric research in rural India: Experience from vadu rural health program

This paper describes unique challenges faced during conduct of community research studies in rural population of Maharashtra at Vadu Rural Health Program, Pune, India. Some of the ethical issues faced include difficulty in comprehending the informed consent by rural families with low education levels and ensuring adequate compensation for study participation without undue inducement, ensuring large number of recruitments during early infancy, ensuring adherence to intervention by care-providers, retention of participants especially in studies having long follow-ups and regulatory compliance for serious adverse event reports are major operational challenges. The delays faced in approvals from the Health Ministry Screening Committee and lack of specific regulatory guidance on community-based conduct of studies pose challenges in terms of study timelines and operational aspect of these studies. Provision of study-related information during prestudy visits, designing patient information sheets in simple language, involving the decision-making member of the family, adequate time for families for decision-making are certain measures that have been useful for effective informed consent administration. Collaboration with accredited social health activists and auxillary nurse midwives for line-listing of pregnancies and births and regular conduction of prestudy visits or community sensitization meetings have been useful for the recruitment of large number of study participants during infancy. Strategies such as provision of universal immunization, selection of field research assistants from the local population, regular home visits, and provision of medical care has been helpful in retention of the study participants. Networking with local health facilities and local government bodies has helped in the provision of medical care to the study participants and in the management of serious adverse events. Our experience can provide important learnings to other investigators from developing countries working in the domain of child health.

Lessons from healthcare personnel screening and management during H1N1 pandemic in preparation for the impending COVID-19 pandemic in a tertiary care hospital in India

Background

In the wake of the COVID-19 pandemic caused by a novel corona virus, health care personnel are at increased risk of acquiring the infection. In preparation for the management of health care personnel that are likely to be infected, we looked in to the data collected during the Influenza pandemic in 2009, caused by a novel strain of H1N1 influenza called swine flu. The care of healthcare personnel in our institution, who had an acute febrile respiratory illness (AFRI) during that period was routed through a single channel using a uniform protocol. We retrospectively analysed the available data, during the initial four months of the pandemic, to draw lessons from it.

Objective

To study the prevalence, clinical profile and risk factors of swine flu among health care personnel during the pandemic of 2009 in a tertiary care hospital in South India.

Methodology

This retrospective study enrolled all the health care personnel including students of a tertiary care institution in South India, who presented with an AFRI between June to August, the initial four months of the swine flu pandemic of 2009. The clinical profile and risk factors were extracted. The results of the RT PCR for swine flu was obtained. Prevalence in each demographic group was calculated and compared. Characteristics of those with swine flu were compared with those who turned negative for the swine flu.

Results

The prevalence of all AFRI and only swine flu among health care personnel during the study period was 18 per thousand and 8.7 per thousand respectively. Highest prevalence of swine flu was found among students and office staff. After adjusting for confounding factors, hyperthermia at presentation was significantly higher {OR = 1.97; 95% CI (1.01–3.76)} among those who tested positive for swine flu as compared with those with other AFRI's. Only 2.5% of the entire AFRI group required admission and there was no mortality.

Conclusion

Health care personnel are at increased risk of acquiring infection. Our study demonstrated that students and office staff were the most susceptible. Unprotected exposure to unknown infectious patients and relatives is likely to have been an important factor. Though the mode of transmission is similar, compared to H1N1, COVID-19 is associated with different comorbidities and has significantly higher mortality. Therefore, in preparation for the COVID-19 pandemic, the personal protective equipment of the healthcare personnel need to be escalated.

•

During a pandemic, health care personnel are at increased risk of acquiring infection.

•

Unprotected exposure to unknown infectious patients is an important factor for transmission.

•

Compared to H1N1, COVID-19 is associated with different comorbidities and has significantly higher mortality.

•

In preparation for the COVID-19 pandemic, the personal protective equipment of the healthcare personnel need to be escalated.

Epidemiology and phylogenetic analysis of respiratory viruses from 2012 to 2015 - A sentinel surveillance report from union territory of Puducherry, India

Background

Acute respiratory infections (ARI) are the most common illnesses affecting people of all ages worldwide. Viruses contribute to 30–70% of acute respiratory infections. Identification of these respiratory viruses is not given high priority except influenza; however, the knowledge about prevalence of non-influenza viruses, their seasonal pattern and genetic evolution have significant epidemiological value.

Methods

As a part of National Influenza-like illness surveillance programme, respiratory specimens were collected children and adults with symptoms of ILI or ARI, between January 2012 and March 2015 (including SARI cases). Real-time PCR was done to identify 13 respiratory viruses. Sequencing was done for representative isolates of each virus using ABI 3730 Genetic Analyzer.

Results

During the study period between January 2012 and March 2015, a total of 648 patients with symptoms of ARI were included in this study. The mean age of the patients was 20.2 years (SD = 19.13, median = 18); 292 (45.1%) were children (≤13 years) and 356 (54.9%) were adults. Respiratory viruses were identified in 44% (287/648) of all patients. Influenza accounted for the maximum number of cases- 179/648 (27.6%). Among the non-influenza viruses, RSV predominated with 34 cases (5.2%), followed by HMPV 24 (3.7%) and PIV-3 20 (3%). Four patients died due to INF A/H1N1 (2012-2, 2015-2) as a result of acute respiratory distress syndrome (ARDS) (CFR 3.7%). Among the non-influenza viruses, no particular seasonality pattern was observed over the different months of the study period.

Conclusion

Antibiotic usage in treating acute respiratory infections empirically is not justified as nearly half of ARI are due to viruses; nearly 28% of them were due to influenza viruses. Among the non-influenza viruses, RSV predominated, followed by HMPV. This study is based on an active influenza surveillance initiated after 2009 pandemic influenza outbreak, in the Union territory of Puducherry which has contributed significantly to the knowledge of the burden of influenza and non-influenza viruses among children and adults. Such surveillance network has paved the way for better diagnosis and timely therapeutic interventions.

•

First data on the epidemiology of respiratory viruses from this region after 1974.

•

First study to report corona virus, HCoV OC43 from India, and only the second Indian study to document corona virus, HCoV229E. This study is the first study to analyse the genetic sequence of HCoV-229E and OC-43.

•

Influenza accounted for the maximum number of cases in the study population, 27%; four patients died of Acute respiratory distress syndrome (ARDS) due to influenza A/H1N1; CFR- 3.7%.

•

Among the non-influenza viruses, RSV pre-dominated followed HMPV and PIV-3. No deaths were reported due to non-influenza viral ARI. RSV was detected almost equally in adults and children.

•

Distinct pattern was observed in seasonality of influenza viruses but not for non-influenza viruses.

Clinical practice guidelines 2019: Indian consensus-based recommendations on influenza vaccination in adults

Influenza, a common cause of acute respiratory infections, is an important health problem worldwide, including in India. Influenza is associated with several complications; people with comorbidities and the elderly are at a higher risk for such complications. Moreover, the influenza virus constantly changes genetically, thereby worsening therapeutic outcomes. Vaccination is an effective measure for the prevention of influenza. Despite the availability of global guidelines on influenza vaccination in adults, country-specific guidelines based on regional variation in disease burden are required for better disease management in India. With this aim, the Indian Chest Society and National College of Chest Physicians of India jointly conducted an expert meeting in January 2019. The discussion was aimed at delineating evidence-based recommendations on adult influenza vaccination in India. The present article discusses expert recommendations on clinical practice guidelines to be followed in India for adult influenza vaccination, for better management of the disease burden.

Improving preparedness for the next flu pandemic

Pandemic influenza remains the single greatest threat to global heath security. Efforts to increase our preparedness, by improving predictions of viral emergence, spread and disease severity, by targeting reduced transmission and improved vaccination and by mitigating health impacts in low- and middle-income countries, should receive renewed urgency.

CD4 T cells in protection from influenza virus: Viral antigen specificity and functional potential

CD4 T cells convey a number of discrete functions to protective immunity to influenza, a complexity that distinguishes this arm of adaptive immunity from B cells and CD8 T cells. Although the most well recognized function of CD4 T cells is provision of help for antibody production, CD4 T cells are important in many aspects of protective immunity. Our studies have revealed that viral antigen specificity is a key determinant of CD4 T cell function, as illustrated both by mouse models of infection and human vaccine responses, a factor whose importance is due at least in part to events in viral antigen handling. We discuss research that has provided insight into the diverse viral epitope specificity of CD4 T cells elicited after infection, how this primary response is modified as CD4 T cells home to the lung, establish memory, and after challenge with a secondary and distinct influenza virus strain. Our studies in human subjects point out the challenges facing vaccine efforts to facilitate responses to novel and avian strains of influenza, as well as strategies that enhance the ability of CD4 T cells to promote protective antibody responses to both seasonal and potentially pandemic strains of influenza.

Estimation of Burden of Influenza among under-Five Children in India: A Meta-Analysis

BACKGROUND

We estimated the burden of influenza-related acute respiratory tract infection (ARI) among under-fives in India through meta-analysis.

METHODOLOGY

We estimated pooled incidence and proportional positivity of laboratory-diagnosed influenza among under-fives using data from observational studies published from 1 January 1961 to 31 December 2016. Death due to influenza was estimated using a multiplier model.

RESULTS

Influenza-associated ARI incidence was estimated as 132 per 1000 child-years (115-149). The patients positive for influenza among ARI in outpatients and inpatients were estimated to be 11.2% (8.8-13.6) and 7.1% (5.5-8.8), respectively. We estimated total influenza cases during 2016 as 16 009 207 (13 942 916-18 082 769) in India. Influenza accounted for 10 913 476 (9 504 666-12 362 310) outpatient visits and 109 431 (83 882-134 980) hospitalizations. A total of 27 825 (21 382-34 408) influenza-associated under-five deaths were estimated in India in 2016.

CONCLUSION

Influenza imposes a substantial burden among under-fives in India. Public health approach for its prevention and control needs to be explored.

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.

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

OBJECTIVES

This research studies the role of slums in the spread and control of infectious diseases in the National Capital Territory of India, Delhi, using detailed social contact networks of its residents.

METHODS

We use an agent-based model to study the spread of influenza in Delhi through person-to-person contact. Two different networks are used: one in which slum and non-slum regions are treated the same, and the other in which 298 slum zones are identified. In the second network, slum-specific demographics and activities are assigned to the individuals whose homes reside inside these zones. The main effects of integrating slums are that the network has more home-related contacts due to larger family sizes and more outside contacts due to more daily activities outside home. Various vaccination and social distancing interventions are applied to control the spread of influenza.

RESULTS

Simulation-based results show that when slum attributes are ignored, the effectiveness of vaccination can be overestimated by 30%-55%, in terms of reducing the peak number of infections and the size of the epidemic, and in delaying the time to peak infection. The slum population sustains greater infection rates under all intervention scenarios in the network that treats slums differently. Vaccination strategy performs better than social distancing strategies in slums.

CONCLUSIONS

Unique characteristics of slums play a significant role in the spread of infectious diseases. Modelling slums and estimating their impact on epidemics will help policy makers and regulators more accurately prioritise allocation of scarce medical resources and implement public health policies.

National burden of hospitalized and non-hospitalized influenza-associated severe acute respiratory illness in Kenya, 2012-2014

BACKGROUND

Influenza-associated respiratory illness was substantial during the emergence of the 2009 influenza pandemic. Estimates of influenza burden in the post-pandemic period are unavailable to guide Kenyan vaccine policy.

OBJECTIVES

To update estimates of hospitalized and non-hospitalized influenza-associated severe acute respiratory illness (SARI) during a post-pandemic period (2012-2014) and describe the incidence of disease by narrow age categories.

METHODS

We used data from Siaya County Referral Hospital to estimate age-specific base rates of SARI. We extrapolated these base rates to other regions within the country by adjusting for regional risk factors for acute respiratory illness (ARI), regional healthcare utilization for acute respiratory illness, and the proportion of influenza-positive SARI cases in each region, so as to obtain region-specific rates.

RESULTS

The mean annual rate of hospitalized influenza-associated SARI among all ages was 21 (95% CI 19-23) per 100 000 persons. Rates of non-hospitalized influenza-associated SARI were approximately 4 times higher at 82 (95% CI 74-90) per 100 000 persons. Mean annual rates of influenza-associated SARI were highest in children <2 years of age with annual hospitalization rates of 147 (95% CI of 134-160) per 100 000 persons and non-hospitalization rates of 469 (95% CI 426-517) per 100 000 persons. For the period 2012-2014, there were between 8153 and 9751 cases of hospitalized influenza-associated SARI and 31 785-38 546 cases of non-hospitalized influenza-associated SARI per year.

CONCLUSIONS

The highest burden of disease was observed among children <2 years of age. This highlights the need for strategies to prevent influenza infections in this age group.

The high frequency of non-aspartic acid residues at HA222 in influenza A(H1N1) 2009 pandemic viruses is associated with mortality during the upsurge of 2015: a molecular and epidemiological study from central India

Influenza A(H1N1) viruses of the 2009 pandemic (A(H1N1)pdm09) continue to cause outbreaks in the post-pandemic period. During January to May 2015, an upsurge of influenza was recorded that resulted in high fatality in central India. Genetic lineage, mutations in the hemagglutinin (HA) gene and infection by quasi-species are reported to affect disease severity. The objective of this study is to present the molecular and epidemiological trends during the 2015 influenza outbreak in central India. All the referred samples were subjected to qRT–PCR for diagnosis. HA gene sequencing (23 survivors and 24 non-survivors) and cloning were performed and analyzed using Molecular Evolutionary Genomic Analyzer (MEGA 5·05). Of the 3625 tested samples, 1607 (44·3%) were positive for influenza A(H1N1)pdm09, of which 228 (14·2%) individuals succumbed to death. A significant trend was observed in positivity (P = 0·003) and mortality (P < 0·0001) with increasing age. The circulating A(H1N1)pdm09 virus was characterized as belonging to clade-6B. Clinically significant mutations were detected. Patients infected with the quasi-species of the virus had a greater risk of death (P = 0·009). This study proposes a robust molecular and clinical surveillance program for the detection and characterization of the virus, along with prompt treatment protocols to prevent outbreaks.

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.

Drug resistance in influenza A virus: the epidemiology and management

Influenza A virus (IAV) is the sole cause of the unpredictable influenza pandemics and deadly zoonotic outbreaks and constitutes at least half of the cause of regular annual influenza epidemics in humans. Two classes of anti-IAV drugs, adamantanes and neuraminidase (NA) inhibitors (NAIs) targeting the viral components M2 ion channel and NA, respectively, have been approved to treat IAV infections. However, IAV rapidly acquired resistance against both classes of drugs by mutating these viral components. The adamantane-resistant IAV has established itself in nature, and a majority of the IAV subtypes, especially the most common H1N1 and H3N2, circulating globally are resistant to adamantanes. Consequently, adamantanes have become practically obsolete as anti-IAV drugs. Similarly, up to 100% of the globally circulating IAV H1N1 subtypes were resistant to oseltamivir, the most commonly used NAI, until 2009. However, the 2009 pandemic IAV H1N1 subtype, which was sensitive to NAIs and has now become one of the dominant seasonal influenza virus strains, has replaced the pre-2009 oseltamivir-resistant H1N1 variants. This review traces the epidemiology of both adamantane- and NAI-resistant IAV subtypes since the approval of these drugs and highlights the susceptibility status of currently circulating IAV subtypes to NAIs. Further, it provides an overview of currently and soon to be available control measures to manage current and emerging drug-resistant IAV. Finally, this review outlines the research directions that should be undertaken to manage the circulation of IAV in intermediate hosts and develop effective and alternative anti-IAV therapies.

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.

Global Role and Burden of Influenza in Pediatric Respiratory Hospitalizations, 1982-2012: A Systematic Analysis

BACKGROUND

The global burden of pediatric severe respiratory illness is substantial, and influenza viruses contribute to this burden. Systematic surveillance and testing for influenza among hospitalized children has expanded globally over the past decade. However, only a fraction of the data has been used to estimate influenza burden. In this analysis, we use surveillance data to provide an estimate of influenza-associated hospitalizations among children worldwide.

METHODS AND FINDINGS

We aggregated data from a systematic review (n = 108) and surveillance platforms (n = 37) to calculate a pooled estimate of the proportion of samples collected from children hospitalized with respiratory illnesses and positive for influenza by age group (<6 mo, <1 y, <2 y, <5 y, 5-17 y, and <18 y). We applied this proportion to global estimates of acute lower respiratory infection hospitalizations among children aged <1 y and <5 y, to obtain the number and per capita rate of influenza-associated hospitalizations by geographic region and socio-economic status. Influenza was associated with 10% (95% CI 8%-11%) of respiratory hospitalizations in children <18 y worldwide, ranging from 5% (95% CI 3%-7%) among children <6 mo to 16% (95% CI 14%-20%) among children 5-17 y. On average, we estimated that influenza results in approximately 374,000 (95% CI 264,000 to 539,000) hospitalizations in children <1 y-of which 228,000 (95% CI 150,000 to 344,000) occur in children <6 mo-and 870,000 (95% CI 610,000 to 1,237,000) hospitalizations in children <5 y annually. Influenza-associated hospitalization rates were more than three times higher in developing countries than in industrialized countries (150/100,000 children/year versus 48/100,000). However, differences in hospitalization practices between settings are an important limitation in interpreting these findings.

CONCLUSIONS

Influenza is an important contributor to respiratory hospitalizations among young children worldwide. Increasing influenza vaccination coverage among young children and pregnant women could reduce this burden and protect infants <6 mo.

The Nicaraguan pediatric influenza cohort study: design, methods, use of technology, and compliance

Background

Influenza causes substantial morbidity and mortality worldwide, yet few data exist on influenza infection rates in tropical, developing countries. In 2011, we established the Nicaraguan Pediatric Influenza Cohort Study (NPICS) to study the burden and seasonality of influenza in Nicaraguan children. Here we describe the study design, methods, and participation data of the NPICS for 2011–2013.

Methods/Design

A total of 1532 children aged 0 to 12 years were enrolled into the study in 2011, and an additional 401 children were enrolled between 2012 and 2013. Children were provided with all of their medical care through the study, and data on medical visits were recorded systematically. A number of surveys were conducted together with a blood sample annually, including a height and weight measurement, a socio-economic status and risk factor survey, and a breastfeeding survey.

Discussion

Unique features of our study include the customized low-cost, open-source informatics system as well as the development of methods to leverage infrastructure and resources by conducting multiple studies in the same setting while maximizing protocol adherence and quality control. These methods should be useful to others conducting large cohort studies, particularly in low-resource settings.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-015-1256-6) contains supplementary material, which is available to authorized users.

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.

Influenza-Associated Disease Burden in Kenya: A Systematic Review of Literature

Background

In Kenya data on the burden of influenza disease are needed to inform influenza control policies.

Methods

We conducted a systematic review of published data describing the influenza disease burden in Kenya using surveillance data collected until December 2013. We included studies with laboratory confirmation of influenza, well-defined catchment populations, case definitions used to sample patients for testing and a description of the laboratory methods used for influenza testing. Studies with or without any adjustments on the incidence rates were included.

Results

Ten studies reporting the incidence of medically-attended and non-medically attended influenza were reviewed. For all age groups, the influenza positive proportion ranged from 5–10% among hospitalized patients, and 5–27% among all medically-attended patients (a combination of in- and outpatients). The adjusted incidence rate of hospitalizations with influenza among children <5 years ranged from 2.7–4.7 per 1,000 [5.7 per 1,000 in children <6 months old], and were 7–10 times higher compared to persons aged ≥5 years. The adjusted incidence of all medically-attended influenza among children aged <5 years ranged from 13.0–58.0 per 1,000 compared to 4.3–26.0 per 1,000 among persons aged ≥5 years.

Conclusions

Our review shows an expanding set of literature on disease burden associated with influenza in Kenya, with a substantial burden in children under five years of age. Hospitalizations with influenza in these children were 2–3 times higher than reported in the United States. These findings highlight the possible value of an influenza vaccination program in Kenya, with children <5 years and pregnant women being potentially important targets.

Contribution of influenza to acute exacerbations of chronic obstructive pulmonary disease in Kashmir, India, 2010-2012

We estimate the contribution of influenza to hospitalizations for acute exacerbations of chronic obstructive pulmonary disease (AECOPD) in Kashmir, India. Prospective surveillance for influenza among patients hospitalized with AECOPD was conducted at a tertiary care hospital. Patients had clinical data collected and nasal/throat swabs tested for influenza viruses. Outcomes among patients with and without influenza were compared with logistic regression adjusting for age and underlying conditions. During October 2010–September 2012, 498 patients hospitalized with AECOPD were enrolled, of whom 40 (8%) had received influenza vaccine. Forty (8%) had influenza; influenza virus detection peaked in winter (January–March). Patients with influenza were more likely to die during hospitalization (adjusted OR 3·4, CI 1·0–11·4) than those without.

Influenza Burden and Transmission in the Tropics

Each year, influenza causes substantial mortality and morbidity worldwide. It is important to understand influenza in the tropics because of the significant burden in the region and its relevance to global influenza circulation. In this review, influenza burden, transmission dynamics, and their determinants in the tropics are discussed. Environmental, cultural, and social conditions in the tropics are very diverse and often differ from those of temperate regions. Theories that account for and predict influenza dynamics in temperate regions do not fully explain influenza epidemic patterns observed in the tropics. Routine surveillance and household studies have been useful in understanding influenza dynamics in the tropics, but these studies have been limited to only some regions; there is still a lack of information regarding influenza burden and transmission dynamics in many tropical countries. Further studies in the tropics will provide useful insight on many questions that remain.

The cost of acute respiratory infections in Northern India: a multi-site study

Background

Despite the high mortality and morbidity resulting from acute respiratory infections (ARI) globally, there are few data from low-income countries on costs of ARI to inform public health policy decisions We conducted a prospective survey to assess costs of ARI episodes in selected primary, secondary, and tertiary healthcare facilities in north India where no respiratory pathogen vaccine is routinely recommended.

Methods

Face-to-face interviews were conducted among a purposive sample of patients with ARI from healthcare facilities. Data were collected on out-of-pocket costs of hospitalization, medical consultations, medications, diagnostics, transportation, lodging, and missed work days. Telephone surveys were conducted two weeks after medical encounters to ask about subsequent missed work and costs incurred. Costs of prescriptions and diagnostics in public facilities were supplemented with WHO-CHOICE estimates of hospital bed costs. Missed work days were assigned cost based on the national annual per capita income (US$1,104). Non-medically attended ARI cases were identified from an ongoing community-based ARI surveillance project in Faridabad.

Results

During September 2012-March 2013, 1766 patients with ARI were enrolled, including 451 hospitalized patients, 1056 outpatients, and 259 non-medically attended patients. The total direct cost of an ARI episode requiring outpatient care was US$4- $6 for public and $3-$10 for private institutions based on age groups. The total direct cost of an ARI episode requiring hospitalized care was $54-$120 in public and $135-$355 in private institutions. The cost of ARI among those hospitalized was highest among persons aged > = 65 years and lowest among children aged < 5 years. Indirect costs due to missed work days were 16-25% of total costs. The direct out-of-pocket cost of hospitalized ARI was 34% of annual per capita income.

Conclusions

The cost of hospitalized ARI episodes in India is high relative to median per capita income. Data from this study can inform evaluations of the cost effectiveness of proven ARI prevention strategies such as vaccination.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-1685-6) contains supplementary material, which is available to authorized users.

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.

Rates of respiratory virus-associated hospitalization in children aged <5 years in rural northern India

OBJECTIVES

Though respiratory viruses are thought to cause substantial morbidity globally in children aged <5 years, the incidence of severe respiratory virus infections in children is unknown in India where 20% of the world's children live.

METHODS

During August 2009-July 2011, prospective population-based surveillance was conducted for hospitalizations of children aged <5 years in a rural community in Haryana State. Clinical data and respiratory specimens were collected. Swabs were tested by RT-PCR for influenza and parainfluenza viruses, respiratory syncytial virus (RSV), human metapneumovirus, coronaviruses, and adenovirus. Average annual hospitalization incidence was calculated using census data and adjusted for hospitalizations reported to occur at non-study hospitals according to a community healthcare utilization survey.

RESULTS

Of 245 hospitalized children, respiratory viruses were detected among 98 (40%), of whom 92 (94%) had fever or respiratory symptoms. RSV accounted for the highest virus-associated hospitalization incidence (34.6/10,000, 95% CI 26.3-44.7) and 20% of hospitalizations. There were 11.8/10,000 (95% CI 7.9-18.4) influenza-associated hospitalizations (7% of hospitalizations). RSV and influenza virus detection peaked in winter (November-February) and rainy seasons (July), respectively.

CONCLUSION

Respiratory viruses were associated with a substantial proportion of hospitalizations among young children in a rural Indian community. Public health research and prevention in India should consider targeting RSV and influenza in young children.