USA:n ihmisissä ilmennyt A H5N1 influenssavirus infektio. Virusten riskien arvioimisesta IRAT

 https://www.cdc.gov/pandemic-flu/php/monitoring/irat-virus-summaries.html

Public Health

May 2, 2025

Results of Influenza Risk Assessment Tool

At a glance

• The Influenza Risk Assessment Tool (IRAT) is a CDC evaluation tool developed with assistance from global animal and human health influenza experts.
• The IRAT is used to assess the potential pandemic risk of influenza A viruses that are not currently circulating in people.
• This latest IRAT assessed two recent clade 2.3.4.4b avian influenza A(H5N1) viruses: A/California/147/2024 and A/Washington/239/2024.
• These viruses scored in the "moderate risk" category for potential emergence and public health impact, similar to previous assessments of earlier clade 2.3.4.4b avian influenza A(H5N1) viruses. These results validate the proactive, coordinated U.S. government response.
• The IRAT does not assess the immediate risk to the public's health, which is unchanged and remains low, and it does not predict future pandemics.

 

... jatkoa (3) (paradigman muutos vai huomaamatta jäänyt evoluutio

 

Influenza viruses spill over periodically from their primordial reservoirs (aquatic fowls) to the intermediate/secondary hosts to facilitate better adaptation and transmission and some of these hosts must remain as permanent niches for sustained IAV transmission. Other than birds, influenza A affects diverse mammalian populations such as pigs, seals, horses, dogs, cats, wild cats, minks, whales, and humans.

 

 The global pandemic of 2009 caused by swine-origin H1N1 was reported in swine, turkey, dogs, and cat [9,10,11,12,13,14].

 

 Over the last few years, influenza infection landscape has widened to include new mammalian hosts such as bats, seals, and whales [6,15,16,17,18].

 

 Humans are the intermediate hosts for many diseases and zoonotic infections can occur in two ways: (1) isolated, dead-end infections which fail to establish and adapt as in the case of Ebola and hantaviruses (2) virus adapts and establishes in the intermediate or secondary hosts, and also sustain horizontal transmission, as in influenza [19]. 

 

 Such stable host-switch events lead to strong adaptations (ex. H5N1 and H9N2) which can resist the evolutionary pressure or the antagonistic environment posed by the novel hosts [20,21,22]. 

 

The factors that govern the virulence, pathogenicity and transmission of influenza viruses could be multifactorial including both viral as well as host factors. Host factors such as availability of the receptors, the presence of host innate immune and other cellular factors, population size and its interconnectivity all govern the sustainability of influenza transmission [23]. 

 

Influenza viral determinants undergo adaptive mutations, to expand or to limit the host range. Among the viral factors, HA glycoprotein is the primary factor determining the host range and interspecies transmission. Other viral proteins such as NP, PB2, and NS1 have also been involved in host range restriction and adaptation [24]. 

 

 For example, avian influenza polymerase possesses a limited function in human hosts and hence host-specific genetic changes have occurred to the polymerase subunits and NP during natural evolution. 

 

Though uncommon in recent times, IAV has been reported in ruminant species in the past. However, a tight host genetic bottleneck might have played a major role in the evolution, preventing the adaptive mutations necessary for the sustained transmission cycles in a novel host.

 

 Interestingly, the recently emerged influenza D, for which cattle are considered to be the primary reservoir, is widespread in cattle herds across the world. 

 

In this review, we conducted a comprehensive search of the available scientific reports/journal articles on influenza over the last century, with reference to bovine species, to understand the timeline of bovine IAV incidences with respect to human pandemics and epidemics, natural and experimental infections, seroepidemiological studies, and the role of bovine cellular and host factors in the evolution of influenza.

2. Literature Search Strategy:  Katso lähde artikkeli!

2019 Jun 17;11(6):561. doi: 10.3390/v11060561

Influenza A in Bovine Species: A Narrative Literature Review

Chithra C Sreenivasan ¹, Milton Thomas ², Radhey S Kaushik ¹, Dan Wang ^1,3, Feng Li ^1,3,*

PMCID: PMC6631717  PMID: 31213032Abstract

jatkoa...(2) perustavaa olennaista yleistietoa influenssoista

 Influenza viruses belong to Orthomyxoviridae family and are negative-sense single-stranded RNA viruses causing acute respiratory disease in a multitude of hosts all over the world. Influenza viruses were recognized as early as the 16th century and the first pandemic officially documented was in 1580 [1]. 

Influenza viruses evolved to form mainly four types: alphainfluenza virus (influenza A), betainfluenza (influenza B), gammainfluenza (influenza C), and deltainfluenza (influenza D) which again diverged to subtypes and lineages, affecting multiple mammalian species worldwide, including humans.

 Influenza viruses undergo antigenic drift—acquiring frequent mutations in HA and NA, which enables the virions to evade the pre-existing immunity to cause seasonal epidemics/epizootics, and antigenic shift—undergoing gene reassortments causing pandemics. 

The most important IAV human pandemics: 1918 Spanish flu (H1N1), 1957–1958 Asian flu (H2N2), 1968 Hong Kong flu (H3N2), and 2009 swine-origin H1N1 emerged during the last century [1].

 Structurally, IAV and IBV genomes have eight RNA segments, whereas ICV and IDV have only seven segments. IAV has hemagglutinin (HA), neuraminidase (NA), matrix proteins (M1, M2), and NP (ribonucleoprotein) as structural proteins; 3 subunits of the RNA polymerase complex, polymerase basic protein 1 (PB1), polymerase basic protein 2 (PB2), and polymerase acidic protein (PA); and 3 nonstructural proteins, NS1, NS2/NEP (nuclear export protein), and PB1-F2.

 Studies have shown that NS2 and M1 protein form complexes that can be detected in purified virions and cell lysates of virus-infected cells [2,3]. Hence, NS2 and (probably) NS1 of IAV are not considered as non-structural proteins, as these proteins can be detected in virions [4].

 IBV possesses six structural proteins, HA, NA, NB, M2, M1, NP and NS2; 3 subunits of RNA polymerase complex, PA, PB1, and PB2; and nonstructural protein NS1 [5].

 ICV and IDV have 4 structural proteins, M2, M1, NP, and the hemagglutinin–esterase fusion (HEF) protein that replaces the HA and NA of IAV or IBV; 3 subunits of RNA polymerase complex, P3, PB1, and PB2; and 2 nonstructural proteins, NS1 and NS2.

 IAV has several subtypes based on the HA and NA proteins. Currently, there are 18 HA and 11 NA subtypes, of which H1 to H16 and N1 to N9 have been isolated from birds; the subtypes H17, H18, N10, and N11 have been identified in bats [6,7]. Out of these, only three HA (H1, H2, H3) and two NA (N1, N2) subtypes have been associated with human epidemics and are capable of sustained transmission [8].    KTS. lähdeartikkeli: 

2019 Jun 17;11(6):561. doi: 10.3390/v11060561

Influenza A in Bovine Species: A Narrative Literature Review

Chithra C Sreenivasan ¹, Milton Thomas ², Radhey S Kaushik ¹, Dan Wang ^1,3, Feng Li ^1,3,*

PMCID: PMC6631717  PMID: 31213032Abstract

Paradigman muutos(1) märehtivän (ruminantia) nautakarjan A influenssavirusalttiuksista (Bovine A influenza)

1. 

 Mitä tiedetään nautakarjan influenssoista edellisvuosikymmniltä- Artikkeli vuodelta 

. 2019 Jun 17;11(6):561. doi: 10.3390/v11060561

Influenza A in Bovine Species: A Narrative Literature Review

Chithra C Sreenivasan ¹, Milton Thomas ², Radhey S Kaushik ¹, Dan Wang ^1,3, Feng Li ^1,3,*

PMCID: PMC6631717  PMID: 31213032Abstract

It is quite intriguing that bovines were largely unaffected by influenza A, even though most of the domesticated and wild animals/birds at the human–animal interface succumbed to infection over the past few decades. Influenza A occurs on a very infrequent basis in bovine species and hence bovines were not considered to be susceptible hosts for influenza until the emergence of influenza D. This review describes a multifaceted chronological review of literature on influenza in cattle which comprises mainly of the natural infections/outbreaks, experimental studies, and pathological and seroepidemiological aspects of influenza A that have occurred in the past. The review also sheds light on the bovine models used in vitro and in vivo for influenza-related studies over recent years. Despite a few natural cases in the mid-twentieth century and seroprevalence of human, swine, and avian influenza viruses in bovines, the evolution and host adaptation of influenza A virus (IAV) in this species suffered a serious hindrance until the novel influenza D virus (IDV) emerged recently in cattle across the world. Supposedly, certain bovine host factors, particularly some serum components and secretory proteins, were reported to have anti-influenza properties, which could be an attributing factor for the resilient nature of bovines to IAV. Further studies are needed to identify the host-specific factors contributing to the differential pathogenetic mechanisms and disease progression of IAV in bovines compared to other susceptible mammalian hosts.

Keywords: ruminants, bovine, cattle outbreaks, Influenza A, host restriction, bovine cell cultures, bovine respiratory disease, bronchopneumonia, epizootic cough, seroprevalence, MDBK cells

Kts. jatkoa 2. Introduction ( ylläolevaan artikkeliin kuuluvaa) 

Sars-1 Covid-19 osoittaa kohonneita ilmenemisiään paikoitellen maapallolla viime viikkoina

 https://data.who.int/dashboards/covid19/summary?n=o

WHO tiedottaa:

SARS-CoV-2 reported cases: Last 28 days

In the 28-day period from 19 May 2025 to 15 June 2025, 87 countries across five WHO regions reported new COVID-19 cases. During this 28-day period, a total of 346,183 new cases were reported, which is an increase compared to the 141,796 new cases reported from 93 countries in the previous 28-day period (Table 2). Overall, 50 countries from Africa, the Americas, Europe, and South-East Asia showed an increase in new cases of over 10%.

 

Country level details are available in | Cases section

Table 2.1. Newly reported COVID-19 confirmed cases by WHO regions

28-days to the date

WHO Region	18 May 2025	15 Jun 2025
World	141,796	346,183
Africa	205	138
Americas	11,600	11,065
Eastern Mediterranean	No value	No value
Europe	14,070	18,613
South-East Asia	115,885	316,364
Western Pacific	36	3

Table 2.2. Number of countries reported newly COVID-19 confirmed cases by WHO regions

28-days to the date

WHO Region	18 May 2025	15 Jun 2025
World	93	87
Africa	26	22
Americas	25	25
Eastern Mediterranean	0	0
Europe	36	33
South-East Asia	4	5
Western Pacific	2	2

 

SARS-CoV-2 variant circulation: Last 28 days

WHO is currently tracking several SARS-CoV-2 variants:

• Variants of Interest: JN.1
• Variants Under Monitoring: LP.8.1, NB.1.8.1, XFG, XEC, KP.3.1.1, and KP.3

The most prevalent variant, LP.8.1, accounted for 26% of all submitted sequences in the week ending on 15 June 2025 which is a decrease from 28% in the week ending on 18 May 2025. NB.1.8.1 accounted for 24% of all submitted sequences in the week ending on 15 June 2025, a slight increase from 23% in the week ending on 18 May 2025. XFG accounted for 19% of all submitted sequences in the week ending on 15 June 2025, a significant increase from 10% in the week ending on 18 May 2025 (Table 3).

During this reporting period, all other variants showed a decreasing or stable trend. Available evidence suggests that LP.8.1, NB.1.8.1, and XFG do not pose additional public health risks relative to other currently circulating SARS-CoV-2 variants. Due to proportionally low detections (less than 1%) for consecutive weeks, LB.1 has been deescalated from being a VUM.

At the regional level, in the week ending on 15 June 2025 compared to the week ending on 18 May 2025, LP.8.1 declined in the European Region, the Western Pacific Region, and the Americas, which were the regions with sufficient data. NB.1.8.1 declined in the Americas but increased in the European Region and the Western Pacific Region. XFG increased in all regions with sufficient data. Additionally KP.3.1.1 increased in the Western Pacific Region and JN.1 increased in the Americas.

 

Country level details are available in | Circulation section

Information on WHO variant monitoring is available in | Variant section

Table 3. Weekly prevalence of SARS-CoV-2 VOIs and VUMs

Variant	Variant type	18 May 2025	25 May 2025	1 Jun 2025	8 Jun 2025	15 Jun 2025
JN.1	VOI	12.4	14.6	15	12.1	12.4
KP.3
	VUM	1.51	2.02	1.4	1.22	1.32
KP.3.1.1
	VUM	5.11	4.87	4.67	3.39	3.7
LP.8.1
	VUM	28.1	27.2	21.9	24.9	25.7
NB.1.8.1
	VUM	23.5	23.7	23.9	26.1	23.8
XEC
	VUM	11.7	7.94	6.61	5.69	6.08
XFG
	VUM	10.2	13.2	19.4	20.3	19.1

Footnote: Variants presented in this table include the respective descendant lineages, except those individually specified elsewhere in the table.

GISAID tieto H5N1 lintuviruksesta ja ihmistartunnoista

GISAID in the News:

H5N1 Bird Flu continues to take its toll in the United States

Clade 2.3.4.4b of the highly pathogenic avian influenza (HPAI) virus causing outbreaks in wild and domestic birds around the world, continues to spread in dairy cows, poultry and other animals across the United States.  Since April 2024, the U.S. CDC confirmed 70 human cases through genome sequence analysis. In three of these cases, the amino acid substitution NA-S247N was identified that may slightly reduce susceptibility to the neuraminidase inhibitor oseltamivir in laboratory tests. The CDC also identified a different change in the polymerase acidic (PA) protein of a virus collected from a recently confirmed human case of H5N1 bird flu in California.

The current outbreak validates the unpredictability of HPAI viruses, as the route of exposure in dairy cows and mode of virus transmission remains unknown. The virus RNA was found at high concentrations in raw milk.  Several animal species at dairy and poultry farms, as well as a growing number of farm workers are affected.  Data from the USDA’s Animal and Plant Health Inspection Service show that the viruses in infected cows, other animals and the farm workers are closely related.  A mammalian adaptation marker (E627K) was noted in only one farm worker so far, with nearly all farm workers developing mild eye symptoms, alongside respiratory symptoms. 

On 11 February 2025, the USDA released specimen data from the first cases of genotype D1.1 detected in dairy cows. Previously, USDA shared data from deceased animals at a Washington wildlife sanctuary and from raw feline pet food samples that cluster genetically and are of the same genotype B3.13.

On 19 March 2025, the CDC released specimen data from the first human case in Ohio. The specimen sequence belongs to genotype D1.3.  Previously, the CDC released data from the first human fatality involving a patient from Louisiana that had been exposed to non-commercial backyard poultry and wild birds. The CDC had also released specimen data collected from farm workers in Iowa and Wisconsin with exposure to infected commercial poultry, with the same D1.1 genotype detected in poultry and wild birds, in human cases in Washington state and notably a severe human case in British Columbia. The latest trees, based on representative subsamples, are dated to 30 June 2025.

Sinikielitaudista, joka on Tanskassa uutta tautia eläimillä ja leviämässä Ruotsin suuntaan.Suomi vielä tautivapaa.

 https://mmm.fi/-/ahvenanmaalla-saa-rokottaa-elaimia-sinikielitautia-vastaan

Sitaatti:

Maa- ja metsätalousministeriö on päättänyt kumota kiellon rokottaa eläimiä märehtijöiden sinikielitautia vastaan Ahvenanmaan maakunnan alueella. Muutos rokotuskieltoon tehtiin maa- ja metsätalousministeriön asetuksella, joka tulee voimaan 27. kesäkuuta.

Päätöksen tarkoituksena on suojata Ahvenanmaan naudat ja lampaat sinikielitautia vastaan. Sinikielitauti on polttiaisten välityksellä leviävä virustauti, jonka eri serotyyppejä esiintyy yleisesti Välimeren alueen maissa.

Uusi serotyyppi 3 on levinnyt Pohjois-Euroopassa vuodesta 2023 alkaen ja saavutti Etelä-Ruotsin syksyllä 2024. Taudin pelätään leviävän Ruotsissa edelleen kesän aikana ja mahdollisesti saapuvan Ahvenanmaalle syksyllä. Polttiaiset voivat kulkeutua tuulen mukana satoja kilometrejä. 

Rokottaminen päätettiin sallia, vaikka tautia ei vielä esiinny Ahvenanmaalla. Halutaan varmistaa, että eläimillä on rokotuksesta saatu vastustuskyky siinä vaiheessa, kun tauti mahdollisesti saapuu Ahvenanmaalle. Rokottamisen jälkeen kuluu vähintään kuusi viikkoa vastustuskyvyn saavuttamiseksi.

Euroopan komissio on hyväksynyt Suomen sinikielitaudista vapaaksi jäsenvaltioksi. Tämän aseman ansiosta märehtijöiden ja kamelieläinten tuontia rajoitetaan alueilta, joilla sinikielitautia esiintyy. Tautivapauden ylläpitämiseksi ja tartunnan varhaiseksi havaitsemiseksi eläinten rokotus sinikielitautia vastaan on ollut kiellettyä tähän asti koko Suomen alueella ja on edelleen kiellettyä muualla kuin Ahvenanmaalla. 

Suomi säilyttää tautivapaan asemansa rokotusten sallimisesta huolimatta, koska tautiseurantaa tehostetaan Ahvenanmaalla ja lähialueilla. 

Rokotus on vapaaehtoista. Eläimen omistaja tilaa rokotuksen eläinlääkäriltä, joka huolehtii rokotuksesta. Eläimen omistaja maksaa rokotteet ja rokotustyön. 
Suomessa on myyntilupa kolmelle sinikielitautirokotteelle. Kahden rokotteen kohde-eläinlajina on nauta ja lammas. Kolmannen rokotteen kohde-eläinlajina on lammas.

Sinikielitauti on märehtijöiden ja kamelieläinten virustauti, jota esiintyy useimmissa Euroopan maissa Suomea, Baltian maita ja Irlantia lukuun ottamatta. Tauti aiheuttaa eläimissä mm. sierainvuotoa, turvotusta ja kuumetta. Lampailla oireet ovat voimakkaampia ja voivat johtaa eläimen kuolemaan.

Tauti voi siirtyä emästä sikiöön ja aiheuttaa luomista tai epämuodostuneita vasikoita tai karitsoita, jos eläin saa tartunnan tiineyden alkuvaiheessa. Lypsylehmillä tauti voi aiheuttaa maidontuotannon laskua. Koska tartunta leviää polttiaisten välityksellä, eläimiä on vaikeaa suojata tartunnalta muulla tavoin kuin rokottamalla. Eläimiä rokotetaan yleisesti sinikielitautia vastaan muissa Euroopan maissa, mm. Ruotsissa. Tauti tai rokotus ei ole riski kuluttajalle ja elintarvikkeita voi myydä ja käyttää ilman rajoituksia. Sinikielitauti ei tartu ihmiseen. 

Asetuksella sallitaan myös eläinten rokotus koko Suomen alueella tutkimushankkeiden yhteydessä. Tämän muutoksen tarkoituksena on mahdollistaa porojen kokeellinen rokotus sinikielitautia vastaan. Tauti ei leviä rokotusten välityksellä. Sinikielitauti tarttuu kaikkiin märehtijöihin ja on mahdollista, että sinikielitauti leviää tulevaisuudessa polttiaisten mukana myös poronhoitoalueelle. 

 Haku: Ruminantia, Blåtungasjuka 

Vastaus: Svar på svenska

 Blåtunga är en virussjukdom som drabbar idisslare som nötkreatur och får, och sprids via svidknott. I Sverige påvisades sjukdomen för första gången på 15 år i september 2024, med spridning längs västkusten och inåt landet. Symptomen kan variera men kan inkludera feber, sår i mun och nos, dreglande, hälta och minskad mjölkproduktion. 

 

Haku suomeksi: Polttiainen (pistävä mäkäräinen)

https://fi.wikipedia.org/wiki/Polttiaiset 

Vektorihyönteiset: 

Polttiaiset (Ceratopogonidae) on hyönteisten heimo. Polttiaiset ovat pienikokoisia, ja jotkin lajit imevät verta ihmisestä ja muista eläimistä, jopa toisista hyönteisistä.

Tuntomerkit Polttiaiset muistuttavat ulkonäöltään surviaissääskiä. Aikuinen polttiainen on noin 1–1,5 millimetriä pitkä. Useimmilla polttiaislajeilla on kirjavat siivet. Koirailla on tuntosarvissaan paljon pitkiä karvoja, naarailla selvästi vähemmän. Polttiaisen pää on alaviistoon ja eturuumis työntyy sen päälle, jolloin hyönteinen näyttää kyttyräselältä. Silmät kiertävät lähes koko pään ympäri ja koskettavat päälaella toisiaan.^[2]

 Ruotsin svidknott:

 https://sv.wikipedia.org/wiki/Svidknott

Virus BTV on orbivirus, dsRNA rakenteinen mja kuuluu reoviridae heimoon  sairastuttaa  infektoituneitten  polttiaisten pistosten kautta märehtijöitä, mutta vaikka ne  sairastuvat  vakvavasti tauti ei niistä tartu toiseen elimeen  eteenpäin. vaan  ainoastaan  siitä verta imeneitten polttiaisten piston kautta. 

 https://fi.wikipedia.org/wiki/Orbivirukset