Skip to main content

#Estimates of #epidemiological #parameters for #H5N1 #influenza in #humans: a rapid review

Image
By G.M.

 Source: MedRxIV, LINK <||> 

Abstract

Background 

The ongoing H5N1 panzootic in mammals has amplified zoonotic pathways to facilitate human infection. Characterising key epidemiological parameters for H5N1 is critical should this become widespread. 

Aim 

To identify and estimate critical epidemiological parameters for H5N1 from past and current outbreaks, and to compare their characteristics with human influenza subtypes. 

Methods 

We searched PubMed, Embase, and Cochrane Library for systematic reviews reporting parameter estimates from primary data or meta-analyses. To address gaps, we searched Google Scholar for studies of any design providing relevant estimates. We estimated the basic reproduction number for the outbreak in the US and estimated the serial interval using data from previous household clusters in Indonesia. We also applied a branching process model to simulate transmission chain size and duration to assess if simulated transmission patterns align with observed dynamics. 

Results 

From 32 studies, we identified H5N1s epidemiological profile as having lower transmissibility (R0 < 0.2) but higher severity compared to human subtypes. Evidence suggests H5N1 has longer incubation (~4 days vs ~2 days) and serial intervals (~6 days vs ~3 days) than human subtypes, impacting transmission dynamics. Key gaps remain regarding latent and infectious periods. 

Conclusions 

We characterised critical epidemiological parameters for H5N1 infection. The current U.S. outbreak shows lower pathogenicity but similar transmissibility compared to prior outbreaks. Longer incubation and serial intervals may enhance contact tracing feasibility. These estimates offer a baseline for monitoring changes in H5N1 epidemiology.

____

Labels:

Comments

Post a Comment

Popular posts from this blog

#USA, Two more #human cases of #H5N1 #birdflu reported in #California

By G.M.
Two cases of bird flu have been reported in San Joaquin County, California, local health officials said. According to a press release issued Friday and reported by the Sacramento Bee , health officials with San Joaquin County Public Health Services said both cases were farm workers who were exposed to infected animals . Both people are showing mild symptoms and are recovering, officials said, adding that there are 34 total confirmed cases across California. In a warning posted on Facebook, health officials said bird flu was “spreading in several farms such as poultry and cattle” and urged residents to take precautions to prevent the spread of the disease. Precautions include the use of protective equipment when handling poultry, dairy cattle or other animals that may be infected, and when handling raw and unpasteurized milk. (...) There are currently 60 confirmed cases of bird flu in the country . While most of the cases are in California , other states with confirmed cases include Col...
Post a Comment
Read more »

Viral #sepsis: #diagnosis, clinical #features, #pathogenesis, and #clinical considerations

By G.M.
Abstract Sepsis , characterized as life-threatening organ dysfunction resulting from dysregulated host responses to infection , remains a significant challenge in clinical practice . Despite advancements in understanding host-bacterial interactions , molecular responses, and therapeutic approaches, the mortality rate associated with sepsis has consistently ranged between 10 and 16%. This elevated mortality highlights critical gaps in our comprehension of sepsis etiology. Traditionally linked to bacterial and fungal pathogens, recent outbreaks of acute viral infections , including Middle East respiratory syndrome coronavirus ( MERS-CoV ), influenza virus, and severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2 ), among other regional epidemics, have underscored the role of viral pathogenesis in sepsis, particularly when critically ill patients exhibit classic symptoms indicative of sepsis. However, many cases of viral-induced sepsis are frequently underdiagnosed because standar...
Post a Comment
Read more »

Rapid #Surge of #Reassortant A(#H1N1) #Influenza Viruses in Danish #Swine and their #Zoonotic Potential

By G.M.
 Source: BioRxIV, https://www.biorxiv.org/content/10.1101/2024.12.11.627926v1?rss=1  Abstract In 2018, a single detection of a novel reassortant swine influenza A virus (swIAV) was made in Denmark . The hemagglutinin (HA) of the virus was from the H1N1 pandemic 2009 (H1N1pdm09) lineage and the neuraminidase (NA) from the H1N1 Eurasian avian-like swine lineage (H1N1av). By 2022, the novel reassortant virus (H1pdm09N1av) constituted 27 % of swIAVs identified through the Danish passive swIAV surveillance program. Sequencing detected two H1pdm09N1av genotypes ; Genotype 1 contained an internal gene cassette of H1N1pdm09 origin , Genotype 2 differed by carrying an NS gene segment of H1N1av origin . The internal gene cassette of Genotype 2 became increasingly dominant, not only in the H1pdm09N1av population, but also in other Danish enzootic swIAV subtypes . Phylogenetic analysis of the HA genes from H1pdm09N1av viruses revealed a monophyletic source , a higher substitution rat...
Post a Comment
Read more »