Influenza aviar H5N1. ¿Debemos preocuparnos?

Desde la segunda mitad de 2022 se ha reportado un aumento de casos de influenza en aves migratorias en Latinoamérica. Los virus influenza A y B son los principales agentes asociados a influenza estacional epidémica en humanos. Los virus influenza A circulan no solo en humanos sino también en animales, incluyendo aves migratorias. El intercambio de segmentos de ARN genómico entre dos virus del mismo tipo aumenta la diversidad de los subtipos circulantes e incluso puede facilitar la generación de progenie viral potencialmente pandémica. La naturaleza zoonótica del virus influenza A puede generar infecciones en humanos con virus de origen animal. El virus influenza A de origen aviar ha ocasionado transmisiones en humanos, incluyendo casos graves y muertes, siendo la influenza A H5N1 la más destacada. Es importante tomar medidas de prevención y control en caso de aumento de casos de influenza en aves migratorias para prevenir posibles pandemias en Chile y el mundo.

Since the second half of 2022, an increase in influenza cases in migratory birds has been reported in Latin America. Influenza A and B viruses are the main agents associated with seasonal epidemic influenza in humans. Influenza A viruses circulate not only in humans but also in animals, including migratory birds. The exchange of genomic RNA segments among two viruses increases the diversity of circulating subtypes and may even facilitate the generation of potentially pandemic viral progeny. The zoonotic nature of influenza A virus can generate infections in humans with animal-origin viruses. Avian-origin influenza A virus has caused transmissions in humans, including severe cases and deaths, with influenza A H5N1 being the most prominent. It is important to take preventive and control measures in case of an increase in influenza cases in migratory birds to prevent possible pandemics in Chile and the world.

Tracking the spread of avian influenza in China: a model based on evolutionary genetics analysis and geographic visualization / 中华急诊医学杂志

ObjectiveTo explore the diverse natural and human factors affect the outbreak and spread of avian influenza. We integrated geographic visualization and evolutionary genetics technique to establish a method to track spread of avian influenza in China.MethodsThe sequence data of type A avian flu virus were provided by NCBI Nucleotide and Protein Databases.We transformed the original data to readable structures for Matlab using E-Utilities software.These MATLAB readable structures represented 8 genes of the virus,they are:RNA polymerase B2 (PB2),polymerase B1 (PB1),polymerase A (PA),hemagglutinin (HA),nucleoprotein (NP),ne(ur)al aminidase (NA),matrix (M1),and non-structural ( NS1 ) proteins.Based on these readable structures,we compared Ka/Ks ratio of different virus strains and identified the gene mutation patterns under different selection pressures.Then we selected the gene that exhibited the highest Ka/Ks ratio and performed a phylogenetic analysis by Jukes-Cantor algorithm.Google Earth layer tools were then used to integrate gene variation and geographic transmission information. Results When we compared these 8 virus genes,the NS1,HA and NA were found to exhibit high Ka/Ks ratio and could be seen to represent the transmission capacity of the virus.Among these,the HA gene has the highest Ka/Ks ratio.When we compare the amino acids encoded by the HA gene using clustering analysis,we found that the relationship between H5N1 avian influenza strains since 2003 in Asia made up an evolutionary tree.This evolutionary tree contained 30 nodes ( 14 branch nodes and 16 leaf nodes).All genes were classified into 4 major groups by the first 3 nodes. And these 4 groups exhibit clear geographic patterns in their spread.The impact of geographic factors on the outbreak of avian influenza in China can be ranked as:inland water bodies ( lakes,reservoirs)＞ major railway paths ＞ density of poultry. ConclusionsThe analysis on the dominant strains' gene mutations in China' s H5N1 found that the outbreaks of avian influenza correlate with avian migration and poultry transportation.

Teoría de la escalera térmica / Thermic stairways theory

In this article we raise the possibility of a potential relationship between body temperature of different spe-cies of animáis and the Avian Flu. We hypothesize that the different valúes of body temperature could act as an enabling mechanism for Influenza virus infection through an adaptative mechanism of the virions in the species susceptible to infection, including human beings.

En el presente artículo se plantea una posible relación entre la temperatura corporal de diferentes especies animales y la presentación de la Gripe aviar. Se postula que los diferentes valores de temperatura corporal podrían actuar como un mecanismo favorecedor de las infecciones por virus Influenza, mediante un mecanismo de tipo ad-aptativo de los viriones en las diversas especies animales susceptibles a la infección, incluyendo al humano.

Threat of an influenza panzooty: a review based on conservation medicine

Among reemerging illnesses, influenza constitutes one of the main concerns. The avian influenza has recently demonstrated the strong transmission capacity of the etiological agent -a virus from the Orthomyxoviridae family - associated to high pathogenic manifestations of the illness. The strong mutation capacity of this virus, through different hosts, reveals how important integrated actions aiming at monitoring its presence in different species are. The swine infection represents an additional concern not only in relation to that species but also in relation to the possibility of the virus to mutate and adapt to humans. The elements that determine the pathogenicity of the various viral subtypes must be well understood, for the tools used to control the illness - such as vaccination - may promote viral mutation and thus render the control even more difficult instead of favoring it. The present review aims at characterizing various components involved in the virus maintenance in different species as well as the determinant elements involved in its evolution, from the point of view of Conservation Medicine, which is the branch of science that deals exactly with the interaction among the environment, human beings, and animals, thus creating a holistic vision not only of the problem but also of the coherent and effective actions involved in their solution.

A influenza representa um dos principais temores dentre as doenças re-emergentes. A gripe aviária tem demonstrado atualmente a grande capacidade de transmissão do agente etiológico, um vírus da família Orthomyxoviridae, associada a manifestações da enfermidade com alta patogenicidade. A grande capacidade de mutação deste vírus utilizando diferentes hospedeiros, denota a importância de ações integradas que visam monitorar sua presença em diferentes espécies. A infecção dos suínos determina uma preocupação adicional não apenas para a espécie mas, com possibilidades de mutação e adaptação do vírus aos seres humanos. Os fatores que determinam a patogenicidade dos diferentes subtipos virais devem ser bem compreendidos, pois as ferramentas utilizadas no controle da enfermidade, como vacinação, podem fomentar a mutação viral e com isto dificultar o controle ao invés de favorecê-lo. Esta revisão tem por objetivo caracterizar vários componentes envolvidos na manutenção do vírus em diferentes espécies, bem como os fatores envolvidos em sua evolução, sob a ótica da medicina da conservação, que é um capítulo da ciência que trata justamente das interações entre o ambiente, o ser humano e os animais, criando assim uma visão holística tanto do problema, como das ações coerentes e efetivas envolvidas na resolução do mesmo.

As novas facetas e a ameaça da gripe aviária no mundo globalizado / New aspects and the threat of an avian flu epidemic in a globalized world

A influenza ou, como é conhecida comumente, a gripe, é uma doença infecciosa aguda causada por um grupo de vírus (com mesmo nome) que acomete várias espécies de animais, desde felinos até aves, passando por humanos. Há cerca de 10 anos têm sido descritos, inicialmente em Hong Kong, surtos de gripe causados por vírus aviários em populações humanas. A seguir, foram descritos surtos na Holanda e no Canadá. Portanto, indaga-se: o mundo corre o risco de um novo surto semelhante ao de 1918, porém com uma população mundial quatro a cinco vezes maior? Qual a velocidade de disseminação desse vírus, visto que as viagens internacionais já não são feitas em navios lentos, mas sim em jatos supersônicos que dão a volta ao mundo em algumas horas? Antes de tudo, o que torna esse vírus tão problemático? Para nós, profissionais de laboratório, é preocupante a questão do diagnóstico etiológico dessas infecções. Como ressaltamos, os quadros de gripe podem ser causados por vários agentes. Portanto, o diagnostico etiológico, básico para intervenções terapêuticas e para que se defina a ocorrência da epidemia, passa a ter relevância ainda maior.

Influenza, or as it is best known, "flu", is an acute respiratory infection caused by a virus that affects many different animal species from felines to birds, including humans.Ten years ago, initialy in Hong Kong and after that in Holand and Canada, outbreaks of avian flu have been increasingly reported in human beings. The question is innevitable: are we in the surge of a new flu pandemic like the one we had in 1918? The perspective is even worse now that we have five times the world population and the international travels are no longer made in slow-going ships but instead in super fast jet planes. For us, laboratory professionals, the question of the laboratory diagnosis is crucial. Considering that so many different viruses are associated with respiratory infections and therapeutic measures depend on this definition, this subject assumes an even greater interest.

The Transmission, Precautionary and Control of Highly Pathogenic Avian Influenza (HPAI) in China / 中国比较医学杂志

This paper reported the history of avian flu outbreaks in China from 1996 to 2006, directed the characteristics of avian influenza outbreaks in recent years. China is one of the biggest poultry producers in the world and many migratory birds go through China, China faces high risk of pandemic bird flu. The continuing occurrence of sporadic human cases indicates that the virus is continuing to circulate in birds in some parts of the country. In the fighting again avian flu virus, China has developed some possible practice on precautionary and control measure. China enhances international cooperation and scientific involvement in the prevention and control of the avian flu. The State Council and Ministry of Agriculture issued the laws and regulations on avian flu. Wild birds may have played a role in getting domestic fowl and human beings infected with bird flu. Poultry manure is considered to be another key source of the spread routes of H5N1 virus, but the bio - security processing in free range poultry farming and waste products is very poor disposition in China. Epidemic control at grassroots level still needs to be strengthened.

Pathological findings in influenza A (H5N1) infection.

This report includes pathological findings in the two patients who died of avian flu infection in Thailand. One of them was the first confirmed human case of H5N1 infection reported in Thailand. The other was the first case that was probably infected by person-to-person transmission. The most affected organ systems are respiratory and reticuloendothelial systems. Both cases revealed diffuse alveolar damage, which is the major cause of death. The former also showed superimposed pulmonary fungal infection.

Knowledge and requirement of information on flu and avian flu among pharmacists in Hanoi city

Background: Flu and avian flu in humans are events in a number of countries all over the world. In Vietnam, there were some investigations on knowledge, attitude and practice for preventing flu and avian flu on several groups of the population and pharmacists in Tra Vinh province. However, there is no research for this issue in Hanoi city while the evident need for the planning of public health programs is required. Objective: To describe knowledge and identify the requirement of flu and avian flu information among pharmacists in Hanoi city. From that, some recommendations for intervention programs are proposed. Subject and methods: A cross-sectional study was conducted on 143 pharmacists in Hanoi city with a structured questionnaire of knowledge and requirement of flu and avian flu information from October, 2007 to January, 2008. Results and Conclusion: Generally, knowledge on flu and avian flu is not yet comprehensive and sufficient. Requirement for flu and avian flu information was quite in demand, especially via television, capacity building training, having more communication materials and experience exchange workshops. Several interventions need to be directed towards: comprehensive communication on flu and avian flu to pharmacists, which aims to help them understand sufficiently and comprehensive about flu and avian flu; capacity improvement for pharmacists should pay attention to several channels such as television broadcasting communication, short-term training, disseminating relevant materials and perhaps experience exchange through seminars.