Quantifying the seasonal #drivers of #transmission for #Lassa fever in #Nigeria (Philos Transact Roy Soc B., abstract)

[Source: US National Library of Medicine, full page: (LINK). Abstract, edited.]

Philos Trans R Soc Lond B Biol Sci. 2019 Jun 24;374(1775):20180268. doi: 10.1098/rstb.2018.0268.

Quantifying the seasonal drivers of transmission for Lassa fever in Nigeria.

Akhmetzhanov AR1, Asai Y1, Nishiura H1.

Author information: 1 Graduate School of Medicine, Hokkaido University , Sapporo, Hokkaido , Japan.



Lassa fever (LF) is a zoonotic disease that is widespread in West Africa and involves animal-to-human and human-to-human transmission. Animal-to-human transmission occurs upon exposure to rodent excreta and secretions, i.e. urine and saliva, and human-to-human transmission occurs via the bodily fluids of an infected person. To elucidate the seasonal drivers of LF epidemics, we employed a mathematical model to analyse the datasets of human infection, rodent population dynamics and climatological variations and capture the underlying transmission dynamics. The surveillance-based incidence data of human cases in Nigeria were explored, and moreover, a mathematical model was used for describing the transmission dynamics of LF in rodent populations. While quantifying the case fatality risk and the rate of exposure of humans to animals, we explicitly estimated the corresponding contact rate of humans with infected rodents, accounting for the seasonal population dynamics of rodents. Our findings reveal that seasonal migratory dynamics of rodents play a key role in regulating the cyclical pattern of LF epidemics. The estimated timing of high exposure of humans to animals coincides with the time shortly after the start of the dry season and can be associated with the breeding season of rodents in Nigeria. This article is part of the theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes’. This issue is linked with the subsequent theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control’.

KEYWORDS: Arenaviridae; Lassa haemorrhagic fever; multimammate rat; reservoir host; seasonality

PMID: 31056054 DOI: 10.1098/rstb.2018.0268

Keywords: Arenavirus; Lassa fever; West Africa.


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Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.