Managing the challenges of a highly pathogenic avian influenza H5N8 outbreak in Uganda: a case study.

In 2016-2017, the H5N8 strain of highly pathogenic avian influenza (HPAI) spread worldwide and Uganda reported the first occurrence of the disease in its poultry and wild birds. Genetic analysis revealed that the virus clusters with 2.3.4.4 group B strains from birds in central and southern Asia, and thus forms part of the 2.3.4.4 group B clade. Since Uganda is in the path of two major migratory bird flyways, it is likely that infected migratory wild birds played a crucial role in the introduction of H5N8 HPAI viruses into Uganda. The outbreaks happened in the districts of Wakiso, Masaka and Kalangala and affected domestic and wild birds. A One Health Multisectoral Coordination Committee, consisting of a National Task Force, Technical Working Groups and District Disaster Management Committees, was immediately activated to coordinate the preparedness and response efforts to control the disease. In all the affected districts, surveillance was intensified on both domestic and wild birds; biosecurity measures were increased; and movement controls, culling, cleaning, disinfection and safe disposal of carcasses were implemented. Awareness of the disease was raised through education materials, leaflets and brochures distributed to farmers. Finally, Uganda successfully controlled the H5N8 outbreak, using its national preparedness and response mechanisms and through collaboration with international partners. The emergence and spread of this virus strain in Uganda and other parts of Africa poses a significant threat to the poultry industry and food security.

En 2016­2017, le sous-type H5N8 du virus de l'influenza aviaire hautement pathogène (IAHP) s'est propagé dans le monde entier. En Ouganda, les premiers cas ont été notifiés chez les volailles et dans l'avifaune. Une analyse génétique a montré que le virus causal était relié aux souches 2.3.4.4 de groupe B trouvées chez des oiseaux d'Asie centrale et du Sud et qu'il appartenait donc au clade 2.3.4.4 des virus du groupe B. L'Ouganda se trouvant sur le tracé de deux voies majeures de migration d'oiseaux, les espèces sauvages d'oiseaux migrateurs ont probablement joué un rôle déterminant dans l'introduction des virus H5N8 de l'IAHP en Ouganda. Les foyers se sont déclarés dans les districts de Wakiso, Masaka et Kalangala, affectant des espèces aviaires domestiques et sauvages. Un Comité de coordination multisectoriel Une seule santé a aussitôt été créé, composé d'un groupe de travail national, de plusieurs groupes techniques d'experts et de comités locaux de gestion des urgences, afin d'assurer la coordination des activités de préparation et de réponse pour lutter contre la maladie. La surveillance des oiseaux domestiques et de l'avifaune a été intensifiée dans tous les districts affectés ; les mesures de biosécurité ont été renforcées ; les mouvements d'animaux ont été soumis à un contrôle ; enfin, des mesures d'abattage, de nettoyage/désinfection et d'élimination sécurisée des cadavres ont été introduites. Une campagne de sensibilisation à la maladie a été organisée avec la distribution aux éleveurs de matériels pédagogiques, dépliants et brochures d'information. L'Ouganda a finalement réussi à contrôler ce foyer dû au virus H5N8 en appliquant les mécanismes nationaux de préparation et de réponse, avec la collaboration de ses partenaires internationaux. L'émergence et la propagation de cette souche virale en Ouganda et dans d'autres régions d'Afrique font peser une lourde menace sur le secteur des productions avicoles ainsi que sur la sécurité alimentaire.

En los años 2016 y 2017 la cepa H5N8 del virus de la influenza aviar altamente patógena (IAAP) se diseminó por el mundo entero y Uganda notificó su primera aparición en las poblaciones de aves salvajes y de corral del país. El análisis genético reveló que el virus se agrupa con cepas 2.3.4.4 del grupo B que se encuentran en aves de Asia central y meridional, de donde se sigue que forma parte del clado 2.3.4.4 del grupo B. Toda vez que por el territorio ugandés pasan dos grandes rutas migratorias, es probable que, en el curso de sus migraciones, ciertas aves salvajes infectadas hayan tenido un papel decisivo en la introducción en el país del virus H5N8 de la IAAP. Los brotes tuvieron lugar en los distritos de Wakiso, Masaka y Kalangala y afectaron a aves tanto domésticas como salvajes. Inmediatamente se activó un comité de coordinación multisectorial de Una sola salud, formado por un grupo de trabajo nacional más una serie de grupos de trabajos técnicos y de comités de distrito de «gestión de catástrofes¼, que tenía por cometido coordinar las actividades de preparación y respuesta para combatir la enfermedad. En todos los distritos afectados se intensificó la vigilancia de las aves domésticas y salvajes, se reforzaron las medidas de seguridad biológica y se instituyeron medidas de control de los movimientos, sacrificio sanitario, limpieza, desinfección y eliminación segura de los animales muertos. También se repartieron entre los productores material pedagógico, prospectos y folletos con el objetivo de dar mejor a conocer la enfermedad. A la postre Uganda, gracias a sus mecanismos nacionales de preparación y respuesta, aunados a la colaboración con contrapartes internacionales, logró controlar el brote causado por el virus H5N8. La aparición y propagación de esta cepa vírica en Uganda y otras partes de África supone una importante amenaza para el sector avícola y la seguridad alimentaria.

Force of infection of Middle East respiratory syndrome in dromedary camels in Kenya.

Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic disease transmitted from dromedary camels to people, which can result in outbreaks with human-to-human transmission. Because it is a subclinical infection in camels, epidemiological measures other than prevalence are challenging to assess. This study estimated the force of infection (FOI) of MERS-CoV in camel populations from age-stratified serological data. A cross-sectional study of MERS-CoV was conducted in Kenya from July 2016 to July 2017. Seroprevalence was stratified into four age groups: <1, 1-2, 2-3 and >3 years old. Age-independent and age-dependent linear and quadratic generalised linear models were used to estimate FOI in pastoral and ranching camel herds. Models were compared based on computed AIC values. Among pastoral herds, the age-dependent quadratic FOI was the best fit model, while the age-independent FOI was the best fit for the ranching herd data. FOI provides an indirect estimate of infection risk, which is especially valuable where direct estimates of incidence and other measures of infection are challenging to obtain. The FOIs estimated in this study provide important insight about MERS-CoV dynamics in the reservoir species, and contribute to our understanding of the zoonotic risks of this important public health threat.

Modelling the species jump: towards assessing the risk of human infection from novel avian influenzas.

The scientific understanding of the driving factors behind zoonotic and pandemic influenzas is hampered by complex interactions between viruses, animal hosts and humans. This complexity makes identifying influenza viruses of high zoonotic or pandemic risk, before they emerge from animal populations, extremely difficult and uncertain. As a first step towards assessing zoonotic risk of influenza, we demonstrate a risk assessment framework to assess the relative likelihood of influenza A viruses, circulating in animal populations, making the species jump into humans. The intention is that such a risk assessment framework could assist decision-makers to compare multiple influenza viruses for zoonotic potential and hence to develop appropriate strain-specific control measures. It also provides a first step towards showing proof of principle for an eventual pandemic risk model. We show that the spatial and temporal epidemiology is as important in assessing the risk of an influenza A species jump as understanding the innate molecular capability of the virus. We also demonstrate data deficiencies that need to be addressed in order to consistently combine both epidemiological and molecular virology data into a risk assessment framework.

Influenza surveillance in animals: what is our capacity to detect emerging influenza viruses with zoonotic potential?

A survey of national animal influenza surveillance programmes was conducted to assess the current capacity to detect influenza viruses with zoonotic potential in animals (i.e. those influenza viruses that can be naturally transmitted between animals and humans) at regional and global levels. Information on 587 animal influenza surveillance system components was collected for 99 countries from Chief Veterinary Officers (CVOs) (n = 94) and published literature. Less than 1% (n = 4) of these components were specifically aimed at detecting influenza viruses with pandemic potential in animals (i.e. those influenza viruses that are capable of causing epidemic spread in human populations over large geographical regions or worldwide), which would have zoonotic potential as a prerequisite. Those countries that sought to detect influenza viruses with pandemic potential searched for such viruses exclusively in domestic pigs. This work shows the global need for increasing surveillance that targets potentially zoonotic influenza viruses in relevant animal species.

Influenza at the animal-human interface: a review of the literature for virological evidence of human infection with swine or avian influenza viruses other than A(H5N1).

Factors that trigger human infection with animal influenza virus progressing into a pandemic are poorly understood. Within a project developing an evidence-based risk assessment framework for influenza viruses in animals, we conducted a review of the literature for evidence of human infection with animal influenza viruses by diagnostic methods used. The review covering Medline, Embase, SciSearch and CabAbstracts yielded 6,955 articles, of which we retained 89; for influenza A(H5N1) and A(H7N9), the official case counts of t he World Health Organization were used. An additional 30 studies were included by scanning the reference lists. Here, we present the findings for confirmed infections with virological evidence. We found reports of 1,419 naturally infected human cases, of which 648 were associated with avian influenza virus (AIV) A(H5N1), 375 with other AIV subtypes, and 396 with swine influenza virus (SIV). Human cases naturally infected with AIV spanned haemagglutinin subtypes H5, H6, H7, H9 and H10. SIV cases were associated with endemic SIV of H1 and H3 subtype descending from North American and Eurasian SIV lineages and various reassortants thereof. Direct exposure to birds or swine was the most likely source of infection for the cases with available information on exposure.