Caspar Geenen
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caspargeenen.bsky.social
Caspar Geenen
@caspargeenen.bsky.social
93 followers 130 following 15 posts
Working on a PhD at Clinical Microbiology Lab, KU Leuven. Investigating new ways to track the spread of infections. #IDEpi
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caspargeenen.bsky.social
In the COVID-19 Omicron surge, #KULeuven combined contact tracing with sequencing.

Only 1/3 of contacts shared the same strain 🤯, so most people misperceived where they got infected.

@thibaut-jonathan.bsky.social and team show how to assess contact tracing accuracy in the future!

#IDSky #EpiSky
A novel methodology for assessing contact tracing precision: Phylogenetic validation of a contact tracing program for COVID-19 in Belgium
During the COVID-19 pandemic, contact tracing was widely used to limit virus propagation and implement targeted disease control measures. It can howev…
www.sciencedirect.com
October 17, 2025 at 1:04 PM
Reposted by Caspar Geenen
jellematthijnssens.bsky.social
🚨 New paper in Eurosurveillance - @karatasmustafa.bsky.social
We used shotgun metagenomics on indoor air in a Belgian daycare to track respiratory, enteric & skin viruses.
👉 40/42 samples contained human viruses—even when kids seemed healthy!
📄 Read here: pubmed.ncbi.nlm.nih.gov/41000028/
September 30, 2025 at 7:43 AM
Reposted by Caspar Geenen
karatasmustafa.bsky.social
New paper out!

We sampled indoor air for a year in a Belgian daycare and used shotgun metagenomics to track viruses. We recovered many viral genomes of interest.

What would you sample next?

Read at @eurosurveillance.org
@emmanuel-microb.bsky.social, @jellematthijnssens.bsky.social
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Figure 3. (A–N) Sequencing coverage plots of genetic sequences of viruses detected in indoor air samples of a daycare and phylogenetic analyses of sequences of (O) two human bocaviruses and (P) one RSV identified in some samples, Belgium, January–December 2022
September 26, 2025 at 1:18 PM
caspargeenen.bsky.social
New study on reaching people with undiagnosed tuberculosis in Rwanda: “… our results suggest that analyzing satellite imagery may allow the identification of urban areas where inhabitants are at higher risk of tuberculosis.”
April 28, 2025 at 12:14 PM
Reposted by Caspar Geenen
yassentch.bsky.social
One of my favorite #ESCMIDGlobal sessions is "Year in #PublicHealth".
Yi Lang Hsu summarizes outbreaks that occurred in the last year: Mpox, Avian Influenza, Marburg, Oropouche!
#PublicHealthSky #IDsky #ESCMIDGlobal2025
April 13, 2025 at 3:50 PM
Reposted by Caspar Geenen
germhuntermd.bsky.social
Our patients persecuted; colleagues and public health institutions under attack. Our field needs to rise up & fight back

Silence=Death Redux: Infectious Diseases, Public Health, and the Imperative to Resist

Viewpoint by @ericmeyerowitz.bsky.social & me

OpenAccess: academic.oup.com/cid/advance-...
Silence=Death Redux: Infectious Diseases, Public Health, and the Imperative to Resist
The second Trump administration has released a torrent of executive policies hostile to public health, science, and marginalized populations. We outline th
academic.oup.com
March 24, 2025 at 2:58 PM
Reposted by Caspar Geenen
ebiomedicine.bsky.social
New #kuleuven study: indoor air sampling to monitor respiratory infections in childcare settings. 🧒🏽🏫 Key findings: 🔬 Sensitive pathogen detection 🌬️ Correlation with CO2 & infection rates 📈 Early outbreak warnings
👇 www.thelancet.com/journals/ebi...
#PublicHealth #Epidemiology #RespiratoryInfections
Interpretation of indoor air surveillance for respiratory infections: a prospective longitudinal observational study in a childcare setting
Our results suggest that air sampling could provide sensitive, responsive epidemiological indicators for the surveillance of respiratory pathogens. Using air CO2 concentrations to normalise such signa...
www.thelancet.com
February 19, 2025 at 9:00 PM
Reposted by Caspar Geenen
docmundele.bsky.social
New publication by Christelle Jouego & cols. maps TB hotspots in Cameroon using OpenStreetMap & WorldPop data. Reveals up to 53% of TB cases go undiagnosed in some regions 🧐. Urgent need to reallocate diagnostic tools where they're needed most. #GlobalHealth #TB www.nature.com/articles/s41...
Mapping of regions with low tuberculosis notification and estimation of diagnostic gaps in Cameroon, evidence from OpenStreetMap and WorldPop data
Scientific Reports - Mapping of regions with low tuberculosis notification and estimation of diagnostic gaps in Cameroon, evidence from OpenStreetMap and WorldPop data
www.nature.com
February 10, 2025 at 4:32 PM
caspargeenen.bsky.social
New study: analysing indoor air to detect outbreaks.

“… Air sampling could provide sensitive, responsive #epidemiology indicators for surveillance of respiratory pathogens…”

See thread for details and previous air sampling work with @emmanuel-microb.bsky.social…

#IDEpi #IDsky #PedsID #KULeuven 🛟
Heatmap chart showing the detection of various pathogens over different sampling weeks (W9 to W30). Pathogens are listed on the y-axis, including viruses and bacteria such as Streptococcus pneumoniae, human coronaviruses, influenza viruses, and others. The x-axis represents the sampling weeks. Black dots indicate detection of the pathogen in the air. The colour gradient, ranging from white to dark red, represents the proportion of positive paper tissue samples, with darker shades indicating higher proportions. This alt text was generated by ChatGPT. A chart showing the relative detection of pathogens in air versus paper tissues, with pathogens listed on the y-axis (e.g., Pneumocystis jirovecii, herpes simplex virus type 1, SARS-CoV-2). The x-axis represents ∆Ct values, where negative values indicate higher detection in air and positive values indicate higher detection in paper tissues. Red dots represent the mean ∆Ct for each pathogen, and horizontal red error bars represent the 95% confidence intervals. Individual grey dots indicate data points for each sample. Pathogens are arranged by their relative prevalence in air and paper tissues. This alt text was generated by ChatGPT.
January 30, 2025 at 10:55 AM
Reposted by Caspar Geenen
jellematthijnssens.bsky.social
🚨 #PhDPosition Opportunity Alert 🚨
Join the Matthijnssens-lab @KU_Leuven to explore the early-life #virome dynamics and their impact on immunity in infants from Ghana & Zambia! 🌍🧬
📅 Start: June 2025
🔗 kuleuven.be/personeel/jobs…#microbiomem#bioinformaticsc#phageg#NGSGS
https://kuleuven.be/personeel/jobs…
January 21, 2025 at 10:31 AM
Reposted by Caspar Geenen
kaitsulliva.bsky.social
It's not so much mutations spontaneously emerging in individuals that is most concerning, but the fact that flu season is ramping up, giving H5N1 more opportunities to mix with human influenza strains, @angierasmussen.bsky.social told me. www.nbcnews.com/health/healt...
In severe bird flu cases, the virus can mutate as it lingers in the body
As the seasonal flu picks up, there are even more opportunities for the bird flu to acquire mutations as the different influenza viruses mix.
www.nbcnews.com
January 3, 2025 at 11:34 PM
caspargeenen.bsky.social
IDEpi: a dedicated Bluesky feed for Infectious Disease Epidemiology.

This feed collects posts tagged with #IDEpi or keyword combinations like #IDSky + #EpiSky.
Comments and suggestions welcome!

Access here: bsky.app/profile/did:...
January 2, 2025 at 9:40 AM
caspargeenen.bsky.social
Hello Bluesky! A quick overview of what we learned doing contact tracing for COVID-19 at KU Leuven.

#IDEpi #PublicHealth #EpiSky #IDSky @Emmanuel_microb

1️⃣ Tracing sources of infections (backward contact tracing) could efficiently slow COVID-19 spread.
(Raymenants, Geenen, et al; Nat Comms)

More👇
Empirical evidence on the efficiency of backward contact tracing in COVID-19 - Nature Communications
Backward contact tracing aims to identify individuals who were infected by the same person as infected an index case, and has been shown to be effective in modelling studies of SARS-COV-2. Here, the a...
www.nature.com
December 30, 2024 at 1:13 PM