Avian Influenza Infections In Humans Research Articles

A H9N2 Human Case and Surveillance of Avian Influenza Viruses in Live Poultry Markets - Huizhou City, Guangdong Province, China, 2021.

What is already known about this topic?An increasing number of human infected avian influenza A (H9N2) cases have been reported. In 2021, 11 human infections with influenza A virus subtype H9N2 (A/H9N2) have been reported in China.What is added by this report?A new case of H9N2 that occurred in April 2021 in Huizhou City, Guangdong Province, China, was reported in this study. Epidemiological and laboratory information of the case and routine influenza surveillance data of avian influenza A were presented in this report.What are the implications for public health practice?The emergence of a human infected with Avian Influenza Virus H9N2 demonstrates that there is an urgent need to strengthen the surveillance of influenza-like illness and live poultry market.

A Comparative Analysis of Risk Perception and Coping Behaviors among Chinese Poultry Farmers Regarding Human and Poultry Infection with Avian Influenza.

Poultry farmers face a dual risk when mutant avian influenza (AI) virus exhibits zoonotic characteristics. A/H5N1 and A/H7N9 are two principal strains of the AI virus that have captured public attention in recent years, as they have both been reported and can infect poultry and humans, respectively. Previous studies have focused either on poultry farmers’ risk perception and biosecurity preventive behaviors (BPBs) against A/H5N1 infection with poultry, or on their risk perception and personal protective behaviors (PPBs) against human infection with A/H7N9, even though these two strains often appear simultaneously. To bridge this research gap, a survey (N = 426) was conducted in the Chinese provinces of Jiangsu and Anhui to assess risk perception and coping behaviors adopted by poultry farmers facing the dual risk of these two viral strains. Paired sample t-tests revealed that farmers’ perceived risk of poultry infection with A/H5N1 was significantly higher than their perceived risk of human infection with A/H7N9, and that their reported frequency of BPBs against A/H5N1 was significantly higher than the frequency of PPBs against A/H7N9. Moreover, farmers were less familiar with AI infection in human beings compared to that in poultry, but they felt a higher sense of control regarding human AI infection. Multivariate regression analyses showed that farm size and perceived risks of both human and poultry infection with AI were positively associated with BPBs and PPBs. The findings of this research suggest that a campaign to spread knowledge about human AI infection among poultry farmers is needed, and that a policy incentive to encourage large-scale poultry farming could be effective in improving implementation of BPBs and PPBs.

Public Health Response to an Avian Influenza A(H7N8) Virus Outbreak in Commercial Turkey Flocks - Indiana, 2016.

In January 2016, highly pathogenic avian influenza (HPAI) A(H7N8) virus and low pathogenicity avian influenza (LPAI) A(H7N8) virus were detected in commercial turkey flocks in Dubois County, Indiana. The Indiana State Department of Health (ISDH) and the Dubois County Health Department (DCHD) coordinated the public health response to this outbreak, which was the first detection of HPAI A(H7N8) in any species (1). This response was the first to fully implement unpublished public health monitoring procedures for HPAI responders that were developed by the U.S. Department of Agriculture (USDA) and CDC in 2015 (Sonja Olsen, CDC, personal communication, October 2017). No cases of zoonotic avian influenza infection in humans were detected during the outbreak.

Gold Nanoparticles with Ligand/Zwitterion Hybrid Layer for Individual Counting of Influenza A H1N1 Subtype Using Resistive Pulse Sensing.

Resistive pulse sensing (RPS) is an analytical technique for detecting particles with nano- to micrometer diameters, such as proteins, viruses, and bacteria. RPS is a promising tool for diagnosis as it can analyze the characteristics of target particles individually from ion current blockades as pulse waveforms. However, it is difficult to discriminate analog targets because RPS merely provides physical information such as size, shape, concentration, and charge density of the analyte. Influenza A virus, which is 80-120 nm in diameter, has various subtypes, demonstrating the diversity of virus characteristics. For example, highly pathogenic avian influenza infections in humans are recognized as an emerging infectious disease with high mortality rates compared with human influenza viruses. Distinguishing human from avian influenza using their differing biological characteristics would be challenging using RPS. To develop a highly selective diagnostic system for infectious diseases, we combined RPS with molecular recognition. Gold nanoparticles (GNPs) that have human influenza A (H1N1 subtype) virus-specific sialic acid receptors on the surface were prepared as a virus label for RPS analysis. A sulfobetaine and sialic acid (ligand) hybrid surface was formed on the GNPs for the suppression of nonspecific interaction. The results show a size change of viruses derived from specific interactions with GNPs. In contrast, no size shift was observed when nonspecific sialic acid receptor-immobilized GNPs were used. Detection of viruses by individual particle counting could be a new facet of diagnosis.

Seasonal, avian and pandemic influenza: are we prepared?

China experienced a very high and severe influenza seasonal epidemics during the past winter and spring of 2017-2018 season. This year of 2018 is the 100(th) anniversary of the 1918 "Spanish influenza" pandemic, a series of papers under the topic "One Hundred Years of Influenza Pandemics" are produced to demonstrate the impact, characteristics and responses of the past influenza pandemics in global and China, to review the progress and experiences of influenza surveillance, prevention and control strategies, vaccination and antivirus in China, and to discuss the gap and challenges of the prevention, control and response to the seasonal influenza, human avian influenza infection and influenza pandemics. We hope this series could help to raise the awareness of the seasonal and pandemic influenza in publics, and to improve the pandemic preparedness in China.

Genetic and biological characterization of H9N2 avian influenza viruses isolated in China from 2011 to 2014.

The genotypes of the H9N2 avian influenza viruses have changed since 2013 when almost all H9N2 viruses circulating in chickens in China were genotype 57 (G57) with the fittest lineage of each gene. To characterize the H9N2 variant viruses from 2011 to 2014, 28 H9N2 influenza viruses were isolated from live poultry markets in China from 2011–2014 and were analyzed by genetic and biological characterization. Our findings showed that 16 residues that changed antigenicity, two potential N-linked glycosylation sites, and one amino acid in the receptor binding site of the HA protein changed significantly from 2011–2014. Moreover, the HA and NA genes in the phylogenetic tree were mainly clustered into two independent branches, A and B, based on the year of isolation. H9N2 virus internal genes were related to those from the human-infected avian influenza viruses H5N1, H7N9, and H10N8. In particular, the NS gene in the phylogenetic tree revealed genetic divergence of the virus gene into three branches labeled A, B, and C, which were related to the H9N2, H10N8, and H7N9 viruses, respectively. Additionally, the isolates also showed varying levels of infection and airborne transmission. These results indicated that the H9N2 virus had undergone an adaptive evolution and variation from 2011–2014.

Antiviral Drugs for the Treatment and Prevention of Influenza

This paper provides an overview of the currently available treatment options for influenza infections. Currently, the options are limited to only one class of drugs known as the neuraminidase inhibitors (NAIs) (oseltamivir, zanamivir, laninamivir and peramivir) as there is widespread resistance against the adamantanes, an older class of antivirals. This review therefore discusses the mode of action, dosing, summary of clinical trial data and resistance within the context of NAIs. Newer antiviral therapies in late-phase clinical trials are also summarized in this review. Oseltamivir is the most commonly used NAI amongst the four different types available. The most recent meta-analysis of placebo-controlled trials demonstrates that for uncomplicated seasonal influenza, oseltamivir reduces symptoms by 16–24 h, while observational studies cumulatively suggest that oseltamivir treatment reduces mortality in severely ill patients. NAIs also play an important role in the treatment and control of avian influenza infections in humans, which is a public health concern due to their high case fatality rate. The latest analysis of data suggests that early treatment with oseltamivir can be attributed to reducing mortality in patients with avian A(H5N1) infections; data regarding oseltamivir effectiveness against A(H7N9) infections is however more limited. During the 2014–2015 influenza season, the frequency of resistance to the NAIs in all circulating viruses was below 1%, but immunocompromised patients infected with influenza are often at higher risk of shedding resistant viruses due to slow viral clearance and extended treatment regimens. Favipiravir, a polymerase inhibitor, has received limited approval for use in Japan, but its use is restricted to novel viruses that are resistant to other antiviral therapies. Antivirals such as thiazolide, nitazoxanide and endonuclease inhibitor, S-033188, are currently in phase III clinical trials and other influenza antivirals are in early or mid-phase clinical trials. This review highlights a lack of different treatment options for influenza infections. While there are four different types of NAIs, in many countries, oseltamivir is the only available option. New therapies are being rapidly developed to meet the need for a greater variety of antivirals, and as such, it is likely that over the next decade, a broader range of influenza therapeutics will become available for treatment.

Avian Influenza Infections in Humans and Poultry of Lebanon: A Mini Review

Avian Influenza Infections in Humans and Poultry of Lebanon: A Mini Review

Dynamics of public opinion under the influence of epidemic spreading

In this paper, we propose a novel model with dynamically adjusted confidence level of others to investigate the propagation of public opinion on whether to buy chicken in the case of avian influenza infection in humans. We study how people adjust their confidence level in other people’s opinions according to their perceived infection risk and how the opinion evolution and epidemic spreading affect each other on different complex networks by taking into account the spreading feature of avian influenza, that is, only people who buy chicken are possible to be infected. The simulation results show that in a closed system, people who support buying chicken and people who are infected can achieve a dynamic balance after a few time-steps, and the final stable state is mainly dependent on the level of people’s risk perception, rather than the initial distribution of the different opinions. Our results imply that in the course of the epidemic spread, transparent and timely announcement of the number of infections and the risk of infection can help people take the right self-protection actions, and thus help control the spread of avian influenza.

Serological evidence of H9N2 avian influenza virus exposure among poultry workers from Fars province of Iran.

BackgroundSince the 1990s, influenza A viruses of the H9N2 subtype have been causing infections in the poultry population around the globe. This influenza subtype is widely circulating in poultry and human cases of AI H9N2 have been sporadically reported in countries where this virus is endemic in domestic birds. The wide circulation of H9N2 viruses throughout Europe and Asia along with their ability to cause direct infection in mammals and humans, raises public health concerns. H9N2 AI was reported for the first time in Iran in 1998 and at present it is endemic in poultry. This study was carried out to evaluate the exposure to H9N2 AI viruses among poultry workers from the Fars province.Methods100 poultry workers and 100 healthy individuals with no professional exposure to poultry took part in this study. Serum samples were tested for antibodies against two distinct H9N2 avian influenza viruses, which showed different phylogenetic clustering and important molecular differences, such as at the amino acid (aa) position 226 (Q/L) (H3 numbering), using haemagglutination inhibition (HI) and microneutralization (MN) assays.ResultsResults showed that 17 % of the poultry workers were positive for the A/chicken/Iran/10VIR/854-5/2008 virus in MN test and 12 % in HI test using the titer ≥40 as positive cut-off value. Only 2 % of the poultry workers were positive for the A/chicken/Iran/12VIR/9630/1998 virus. Seroprevalence of non exposed individuals for both H9N2 strains was below 3 % by both tests. Statistical analyses models showed that exposure to poultry significantly increases the risk of infection with H9N2 virus.ConclusionsThe results have demonstrated that exposure to avian H9N2 viruses had occurred among poultry workers in the Fars province of Iran. Continuous surveillance programmes should be implemented to monitor the presence of avian influenza infections in humans and to evaluate their potential threat to poultry workers and public health.Electronic supplementary materialThe online version of this article (doi:10.1186/s12985-016-0472-z) contains supplementary material, which is available to authorized users.

Silent War to Emerging or Re-emerging Respiratory Infection Diseases Badly Kept in Mind

Recently, a man aged 44 years from South Korea who flew to Hong Kong on May 26, subsequently traveled to Huizhou, Guangdong Province, had drawn the worldwide attention. First laboratory-confirmed case of middle east respiratory syndrome (MERS) finally landed in China, 3 years after the first identification of MERS coronavirus (MERS-CoV) in Saudi Arabia, 2012.[1] In reality actually, MERS did not attract much attention in China till now although we had alerted about the possibility of its importation, or even pandemic.[2] A similar phenomenon has happened in South Korea, lacking of awareness among health care workers and the general public, contributing to suboptimal infection prevention and control measures in health facilities, and finally cause the outbreak of MERS in South Korea and the exported case to China. Fortunately, we have won out in the battle, and no additional cases have been identified among close contacts in China (n = 75). Meanwhile, we still have lingering fears as there are sporadic infections and outbreaks all over the world.

Imaging manifestations and pathological analysis of severe pneumonia caused by human infected avian influenza (H7N9)

ObjectiveTo investigate the imaging and pathological findings of severe pneumonia caused by human infected avian influenza (H7N9), and therefore to further understand and improve diagnostic accuracy of severe pneumonia caused by human infected avian influenza (H7N9). MethodsThe relevant clinical and imaging data of 19 cases, including 10 males and 9 females, with pneumonia caused by human infected avian influenza (H7N9) was retrospectively analyzed. One of the cases had received percutaneous lung biopsy, with the clinical, imaging and pathological changes possible to be analyzed. ResultsThe lesions were mainly located at lower lobes and dorsal of lungs, involving multiple lobes and segments. Ground-glass opacities and/or pulmonary opacities were the more often imaging manifestations of severe pneumonia caused by human infected avian influenza (H7N9) in early and evolving phases (19/19,100%). By biopsy following percutaneous lung puncture, exudation of slurry, cellulose, RBC and neutrophils, formation of hyaline membrane, squamous metaplasia and organizing exudates were observable at the alveolar space. Some of alveoli collapsed, and some responded to show compensatory emphysema. ConclusionThe imaging features of severe pneumonia caused by human infected avian influenza (H7N9) include obvious ground-glass opacity and pulmonary consolidation, mainly at lower lobes and dorsal of lungs, with rapid changes. The cross-analysis of imaging and pathology preliminary can elucidate the pathological mechanisms of ground-glass opacities and pulmonary consolidation of severe pneumonia. Such an intensive study is beneficial to prompt clinicians to observe and evaluate the progress of the disease. In addition, it is also in favor of managing the symptoms and reducing the mortality rate.

Initial computed tomography findings of pneumonia in patients with human infected avian influenza (H7N9)

PurposeThe aim of this study was to assess initial computed tomography (CT) findings in patients diagnosed with H7N9 virus-associated pneumonia. Samples and methodsFrom March 2013 to July 2013, 14 hospitalized patients aged 47–81 years with a mean of 67.4 ± 9.7 years infected by avian influenza virus H7N9underwent chest CT scanning. The initial CT scans were obtained at d 7.6 ± 2.8 (range, 3–10days) after onset. The pattern, distribution, extent of the lesions, and their changes in follow-up CT scans were evaluated. ResultsAll patients presented a mixture of ground glass opacities and areas of consolidation on CT images. Air bronchogram was observed in 11 patients (78.6%). The coverage of the ground glass opacities was at least threefold larger than that of the consolidation in 7 patients (57.1%). The lesions were bilateral with multifocal distribution (n = 13); bilateral and diffuse (n = 1). The abnormalities had a predominantly subpleural and central distribution in 11 patients (78.6%) and a subpleural distribution in the other 3 patients (21.4%). Ten patients (71.4%) were found with pneumonic infiltration to the extent of ≥40%.Pleural effusion was found in 9 patients (64.3%). Follow-up CT scans in 10patients showed progress of the lesions in 8 patients, with a slow improvement thereafter. ConclusionPredominant ground glass opacities and less dominant consolidations, commonly along with air bronchogram, multifocal or bilateral involvement and a subpleural and central distribution, were initial CT findings of pneumonia in patients with avian influenza (H7N9). Extensive pneumonic infiltration and pleural effusion were common. The disease exhibited rapid progress of the lesions in the early stage of infection.

Notifiable disease reporting among public sector physicians in Nigeria: a cross-sectional survey to evaluate possible barriers and identify best sources of information.

BackgroundSince 2001, Nigeria has collected information on epidemic-prone and other diseases of public health importance through the Integrated Disease Surveillance and Response system (IDSR). Currently 23 diseases are designated as “notifiable” through IDSR, including human infection with avian influenza (AI). Following an outbreak of highly pathogenic avian influenza A(H5N1) in Nigerian poultry populations in 2006 and one laboratory confirmed human infection in 2007, a study was carried out to describe knowledge, perceptions, and practices related to infectious disease reporting through the IDSR system, physicians’ preferred sources of heath information, and knowledge of AI infection in humans among public sector physicians in Nigeria.MethodsDuring November to December 2008, 245 physicians in six Nigerian cities were surveyed through in-person interviews. Survey components included reporting practices for avian influenza and other notifiable diseases, perceived obstacles to disease reporting, methods for obtaining health-related information, and knowledge of avian influenza among participating physicians.ResultsAll 245 respondents reported that they had heard of AI and that humans could become infected with AI. Two-thirds (163/245) had reported a notifiable disease. The most common perceived obstacles to reporting were lack of infrastructure/logistics or reporting system (76/245, 31%), lack of knowledge among doctors about how to report or to whom to report (64/245, 26%), and that doctors should report certain infectious diseases (60/245, 24%). Almost all participating physicians (>99%) reported having a cell phone that they currently use, and 86% reported using the internet at least weekly.ConclusionsAlthough the majority of physicians surveyed were knowledgeable of and had reported notifiable diseases, they identified many perceived obstacles to reporting. In order to effectively identify human AI cases and other infectious diseases through IDSR, reporting system requirements need to be clearly communicated to participating physicians, and perceived obstacles, such as lack of infrastructure, need to be addressed. Future improvements to the reporting system should account for increased utilization of the internet, as well as cell phone and email-based communication.Electronic supplementary materialThe online version of this article (doi:10.1186/s12913-014-0568-3) contains supplementary material, which is available to authorized users.

Zanamivir for the treatment of avian influenza infections in humans

Zanamivir is currently not recommended by the WHO for the first-line treatment of human influenza A (H5N1) infections. Zanamivir pharmacokinetics and antiviral efficacy were reviewed to assess the basis for this recommendation. Following inhalation of 10 mg zanamivir in healthy humans, the drug is widely distributed throughout the lungs. Mean lung sputum concentrations of zanamivir are 1441 and 235 ng/ml at 6 and 12 h postinhalation, respectively. Following repeated dosing to patients, mean steady-state Cmax and Cmin plasma zanamivir concentrations are approximately 60 and 4 ng/ml, respectively. Zanamivir has high in vitro activity against H5N1 strains isolated from patients (IC50 0.3–0.7 ng/ml) including oseltamivir-resistant strains. These data support a reassessment of zanamivir's role in the treatment of human H5N1 infections

Medical Management of Influenza Infection

Antiviral drugs are important in the management of seasonal influenza and critical to pandemic planning. Although several other classes of anti-influenza compounds exist, the neuraminidase (NA) inhibitors are currently the only option in most clinical settings. These drugs, zanamivir and oseltamivir, prevent the release of newly replicated influenza virions from infected cells. They are highly effective when used for treatment of seasonal influenza early in the course of infection, or for prevention when given soon after exposure. Treatment strategies for avian influenza infections in humans are still provisional owing to inadequate clinical data. As predicted by molecular studies, resistance to the NA inhibitors is now emerging, although at a level less significant than adamantane resistance. NA inhibitor resistance is a cause for concern if indeed some mutant strains of avian influenza are transmissible and pathogenic. In the near term, appropriate use of the available NA inhibitors will be of major benefit in lessening morbidity and mortality due to influenza infection. Priorities include developing appropriate formulations and guidelines for use of these drugs in children and people infected with avian influenza, study of the mechanisms and clinical significance of drug resistance, and identification of new antiviral therapies that target different points in the viral life cycle in order to limit the effect of emerging drug resistance.

Expert consultation on diagnosis of H5N1 avian influenza infections in humans

Expert consultation on diagnosis of H5N1 avian influenza infections in humans

Pandemic (Avian) Influenza

Pandemics of influenza have been reported since the early sixteenth century. Recent pandemics include the Spanish flu (H1N1) from 1918 to 1920 (resulting in approximately 50 million deaths worldwide); the Asian flu (H2N2) from 1957 to 1958 (resulting in more than 1 million deaths); the Hong Kong flu (H3N2) from 1968 to 1970 (responsible for approximately 700,000 deaths). Avian influenza viruses have now been identified as a source of novel hemagglutinin (HA) and neuraminidases (NAs) associated with pandemics. Although infections in humans with avian strains are uncommon, several outbreaks of severe influenza with highly virulent H5N1 strains derived from infected poultry were reported in China and other Asian countries since 2003. Large-scale culling operations and intensified surveillance led to eradication of H5N1 infection in poultry in some countries, but H5N1 infection in wild birds and domestic poultry has become endemic in many countries. The potential exists for global pandemics of unprecedented magnitude. In this review, we discuss the epidemiology and genetics of avian influenza viruses, the potential for transmission of disease to humans, clinical features of avian influenza infections in humans, appropriate diagnostic testing, and treatment. We also discuss global efforts for disease prevention via a host of programs, including intensified surveillance, culling of infected birds, education of medical personnel and the public, production of vaccines, and use of specific antiviral agents (e.g., adamantanes and neuraminidase inhibitors).

Practical Problems in Controlling H5N1 High Pathogenicity Avian Influenza at Village Level in Vietnam and Introduction of Biosecurity Measures

After a consultancy mission funded by a nongovernmental organization (NGO), information was collected on the dynamics of avian influenza (AI) infection at the rural level in a Vietnamese province with several ongoing outbreaks. AI outbreaks are frequent at village level due to environmental, ecological, agroecological, physical, social, and cultural factors, the underlying factor being poor hygienic conditions. Viral circulation is facilitated by the interactions of the integrated aquaculture, animal raising, horticulture agroecosystem, which relies in the peculiar integration of aquaculture (ponding), animal activities, and horticulture and by the connections with the live-bird market system. The interactions of these factors determine the complex system in which wild birds interact with domestic birds and in which people are constantly exposed to sources of infection, leading to the association between poverty and AI infection in humans. This experience underlines that despite all efforts by the Vietnamese Government, international institutions, and the NGO sector, awareness of AI at the village level needs to be improved. In turn, the leading institutions and international donors funding projects of technical cooperation aimed at tackling AI in Vietnam should invest in a system based on a deep knowledge of the practical problems of village condition to address AI with an effective approach. On the basis of the data collected during the mission, particularly on rural and semi-intensive poultry rearing systems, proposals that encompass the application of an effective vaccination strategy including backyard flocks coupled with dissemination of relevant information on biosecurity measures have been developed for decision makers.

Inactivation of Avian Influenza Viruses by Chemical Agents and Physical Conditions: A Review

The recent outbreaks of avian influenza (AI) worldwide have highlighted the difficulties in controlling this disease both in developed and in developing countries. Biosecurity is considered the most important tool to prevent and control AI. In certain areas of the world, AI has become endemic and the recent outbreaks in Europe and Africa show that the epidemiological situation is evolving in an unprecedented way. The consequences of this situation are economic losses to the poultry industry, food security issues in developing countries and a serious threat to human health, due to the direct consequences of AI infection in humans, and more alarmingly due to the risk of the generation of a new pandemic virus from the animal reservoir. In this paper, the physical and chemical methods of inactivating AI viruses are reviewed, with particular emphasis on the practicalities of using such methods in the poultry industry.