Vladimir Grosbois

• PhD
• French Agricultural Research Centre for International Development

Many pathogens have the capacity to infect multiple hosts. Multi-species epidemiological systems are characterized by populations that interact and perform different functions in pathogen transmission and maintenance. This study investigated the epidemiological dynamics of foot-and-mouth disease (FMD) virus in cattle and goats and their respective...

Crimean-Congo Haemorrhagic Fever (CCHF) is a tick-borne zoonosis with significant public health implications due to its expanding geographic distribution and potential for severe outcomes in humans. This study represents the first serological survey conducted in mainland France to detect antibodies against the Crimean-Congo Haemorrhagic Fever Virus...

Host choice is a determining component of tick population and pathogen transmission dynamics. In Europe, ticks of the genus Hyalomma, which are involved in the transmission of several pathogens such as the Crimean Congo Haemorrhagic fever (CCHF) virus, are suspected to be spreading into new territories where they were previously unreported. Therefo...

African buffalo and cattle interfaces are expanding on the African continent due to the encroachment of human activities into savanna and forest habitats. These interfaces are especially important for managing the risk of pathogen transmission that can threaten small-scale and commercial livestock production, public health and biodiversity conserva...

Peste des petits ruminants (PPR) virus causes a major disease in domestic and wild small ruminants. Understanding the role of wildlife in PPR virus ecology is important for PPR control and its eradication targeted worldwide in 2030. Developing diagnostic tools that provide reliable data for PPR detection in wildlife will help monitor wild populatio...

Crimean–Congo hemorrhagic fever (CCHF) is a viral zoonotic disease resulting in hemorrhagic syndrome in humans. Its causative agent is naturally transmitted by ticks to non-human vertebrate hosts within an enzootic sylvatic cycle. Ticks are considered biological vectors, as well as reservoirs for CCHF virus (CCHFV), as they are able to maintain the...

The circulation of livestock pathogens in the pig industry is strongly related to animal movements. Epidemiological models developed to understand the circulation of pathogens within the industry should include the probability of transmission via between-farm contacts. The pig industry presents a structured network in time and space, whose composit...

Decisions regarding the implementation of prevention and intervention measures rely on the assessment through the analysis and interpretation of surveillance data of the epidemiological status of target populations or of focal units in target populations. Because they are generated through imperfect reporting, diagnosing, sampling and testing proce...

In Nature Communications Biology: The maintenance of infectious diseases requires a sufficient number of susceptible hosts. Host culling is a potential control strategy for animal diseases. However, the reduction in biodiversity and increasing public concerns regarding the involved ethical issues have progressively challenged the use of wildlife cu...

Rift Valley fever (RVF) is endemic in northern Senegal, a Sahelian area characterized by a temporary pond network that drive both RVF mosquito population dynamics and nomadic herd movements. To investigate the mechanisms that explain RVF recurrent circulation, we modelled a realistic epidemiological system at the pond level integrating vector popul...

Rift Valley fever (RVF) is endemic in northern Senegal, a Sahelian area characterized by a temporary pond network that drive both RVF mosquito population dynamics and nomadic herd movements. To investigate the mechanisms that explain RVF recurrent circulation, we modelled a realistic epidemiological system at the pond level integrating vector popul...

Southern rice black-streaked dwarf virus (SRBSDV), which causes severe disease symptoms in rice (Oriza sativa L.) has been emerging in the last decade throughout northern Vietnam, southern Japan and southern, central and eastern China. Here we attempt to quantify the prevalence of SRBSDV in the Honghe Hani rice terraces system (HHRTS)—a Chinese 130...

Information about infectious diseases at the global level relies on effective, efficient and sustainable national and international surveillance systems. Surveillance systems need to be regularly evaluated to ensure their performance, the quality of the data and information provided, as well as to allocate resources efficiently. Currently available...

Foot and mouth disease (FMD) is an important livestock disease impacting mainly intensive production systems. In southern Africa, the FMD virus is maintained in wildlife and its control is therefore complicated. However, FMD control is an important task to allow countries access to lucrative foreign meat market and veterinary services implement dra...

This study aimed to analyze the financial impact of foot-and-mouth disease (FMD) outbreaks in cattle at the farm-level and the benefit–cost ratio (BCR) of biannual vaccination strategy to prevent and eradicate FMD for cattle in South Vietnam. Production data were collected from 49 small-scale dairy farms, 15 large-scale dairy farms, and 249 beef fa...

West Nile disease, caused by the West Nile virus (WNV), is a mosquito-borne zoonotic disease affecting humans and horses that involves wild birds as amplifying hosts. The mechanisms of WNV transmission remain unclear in Europe where the occurrence of outbreaks has dramatically increased in recent years. We used a dataset on the competence, distribu...

Newcastle disease (ND) is endemic in West Africa, which has also experienced outbreaks of highly pathogenic avian influenza (AI) H5N1 since 2006. We aimed to estimate the prevalence and incidence of AI and ND in village poultry in Mali and to identify associated risk factors. A longitudinal serologic study was conducted between November 2009 and Fe...

Effective control of many diseases requires the accurate detection of infected individuals. Confidently ascertaining whether an individual is infected can be challenging when diagnostic tests are imperfect and when some individuals go for long periods of time without being observed or sampled. Here, we use a multi-event capture-recapture approach t...

Humans live increasingly in the proximity of natural areas, leading to increased interactions between people, their livestock and wildlife. Aim: We explored the role of these interactions in the risk of disease transmission (foot-and-mouth disease (FMD)) between cattle and the African buffalo (the maintenance host) and how a top predator, the lion...

One of the key parameters of these models is the contact rate between infectious and susceptible hosts which, despite its direct impact on the frequency of the transmission of parasites and pathogens, is often estimated but rarely measured accurately. This is particularly true for multi-species systems involving complex transmission cycles, such as...

In most European countries, data regarding movements of live animals are routinely collected and can greatly aid predictive epidemic modeling. However, the use of complete movements’ dataset to conduct policy-relevant predictions has been so far limited by the massive amount of data that have to be processed (e.g., in intensive commercial systems)...

Summary: Dromedary camels are the source of zoonotic infection with MERS coronavirus (MERS-CoV) and therefore it is important to understand the transmission dynamics of this virus in camel herds. Blood samples and nasal swabs were collected between January and March 2015 and tested virologically to identify factors contributing to variations in MER...

The force of infection (FOI) is one of the key parameters describing the dynamics of transmission of vector-borne diseases. Following the occurrence of two major outbreaks of Rift Valley fever (RVF) in Madagascar in 1990–91 and 2008–09, recent studies suggest that the pattern of RVF virus (RVFV) transmission differed among the four main eco-regions...

The canalization hypothesis postulates that the rate at which trait variation generates variation in the average individual fitness in a population determines how buffered traits are against environmental and genetic factors. The ranking of a species on the slow-fast continuum - the covariation among life-history traits describing species-specific...

[This corrects the article DOI: 10.1371/journal.pntd.0004827.].

Supplementary dataset. This file includes supplementary data. (DOCX)

BACKGROUND:Rift Valley fever (RVF) is a vector-borne disease affecting ruminants and humans. Madagascar was heavily affected by RVF in 2008-2009, with evidence of a large and heterogeneous spread of the disease. The identification of at-risk environments is essential to optimize the available resources by targeting RVF surveillance in Madagascar. H...

Scatterplot of observed versus predicted seroprevalences at the district level. Seroprevalence has been predicted for each age category in each communes sampled. For each district the sampling has been reconstructed taking into account the communes sampled and the number of animals sampled in each commune. Grey points correspond to districts where...

Comparison of the values and weight of AIC for the cattle and human models. (DOCX)

Disease prevalence in wildlife is governed by epidemiological parameters (infection and recovery rates) and response to infection, both of which vary within and among individual hosts. Studies quantifying these individual‐scale parameters and documenting their source of variation in wild hosts are fundamental for predicting disease dynamics. Such s...

One Health for the Real World: zoonoses, ecosystems and wellbeing. Zoological Society of London, ZSL London Zoo

The coexistence of protected areas and neighbouring communal areas in Southern Africa is jeopardised by negative interactions between wildlife and villagers and their livestock. The African buffalo (Syncerus caffer) has often been blamed for a significant proportion of the “human-wildlife conflicts”, mainly through the transmission of pathogens to...

Understanding the complexity of live pig trade organization is a key factor to predict and control major infectious diseases, such as classical swine fever (CSF) or African swine fever (ASF). Whereas the organization of pig trade has been described in several European countries with indoor commercial production systems, little information is availa...

A study was conducted between May 2013 and August 2014 in three provinces of Vietnam to investigate financial impacts of swine diseases in pig holdings in 2010-2013. The aim of the study was to quantify the costs of swine diseases at producer level in order to understand swine disease priority for monitoring at local level. Financial impacts of por...

General objective : Assess the temporal pattern and the potential risk factors related to human illness caused by MERS-CoV.

Phase 1: mapping the virus in Asia & Africa

Live bird markets (LBMs) play an important role in the transmission of avian influenza (AI) and Newcastle disease (ND) viruses in poultry. Our study had two objectives: (1) characterizing LBMs in Mali with a focus on practices influencing the risk of transmission of AI and ND, and (2) identifying which LBMs should be targeted for surveillance and c...

Corsica is a French Mediterranean island with traditional extensive pig farming oriented towards the production of high quality cured meat products. The increasing success of these cured products in continental Europe has triggered the development and organisation of an extensive pig farming industry. However, these pig farming practices have seldo...

The effectiveness of animal health surveillance systems depends on their capacity to gather sanitary information from the animal production sector. In order to assess this capacity we analyzed the flow of sanitary information regarding Highly Pathogenic Avian Influenza (HPAI) suspicions in poultry in Vietnam. Participatory methods were applied to a...

For several major infectious diseases, the structure of contact patterns between herds trough live animal trade will determine the dynamic of their spread. However, complete data on trade movements can be difficult to include in epidemic models, being not available on time, too time-consuming or computationally challenging. The objectives of this p...

Newcastle disease (ND) is an endemic disease in village chickens in Ethiopia with substantial economic importance. The sensitivity (Se) and specificity (Sp) of a blocking enzyme-linked immunosorbent assay (bELISA, Svanova Biotech), indirect ELISA (iELISA, Laboratoire Service International) and haemagglutination inhibition (HI) test for ND virus (ND...

PURPOSE: Bushpigs (Potamochoerus larvatus) are a significant source of cheap proteins in several rural areas of Madagascar. We aim to identify diseases of bushpigs in those areas, explore their role as sources of pathogens for livestock and humans, and understand how hunting and trade may affect epidemiological risks. METHODS: Our integrated approa...

Data on long-term circulation of pathogens in wildlife populations are seldom collected, and hence understanding of spatial-temporal variation in prevalence and genotypes is limited. Here, we analysed a long-term surveillance series on influenza A virus (IAV) in mallards collected at an important migratory stopover site from 2002 to 2010, and chara...

Le potamochère, Potamochoerus larva- tus, est un réservoir sauvage potentiel de maladies enzootiques à Madagascar. Parmi celles-ci, la peste porcine africaine (Ppa) est une des plus inquiétantes. Diag- nostiquée dans ce pays depuis 1998, cette maladie virale majeure d’un point de vue socio-économique est inféodée aux suidés et y est encore aujourd’...

The Potamochoerus larvatus bush-pig is a potential reservoir of enzootic diseases in the wild in Madagascar. Among these, African swine fever (ASF) is one of the most alarming. Diagnosed in the country in 1998, this specific viral swine disease is still widespread. Characterising the transmission of the virus between domestic pigs and wild pigs is...

Wild birds, particularly duck species, are the main reservoir of influenza A virus (IAV) in nature. However, knowledge of IAV infection dynamics in the wild bird reservoir, and the development of immune responses, are essentially absent. Importantly, a detailed understanding of how subtype diversity is generated and maintained is lacking. To addres...

Distribution of p-values over randomly generated independent subsamples for the long lag (≥7 days between isolation) and common subtypes. (A) p-value distribution of MC Fisher's test at the level of subtype; (B) p-value distribution of Fisher's test at the level of clade; (C) p-value distribution of MC Fisher's test at the level of group. (TIF)

IAV detection probability for H7, H9 and H11 Clades as a function of time and previously detected infections. The x-axis represents time in days since first detection of a virus. The y-axis depicts the probability of detection. Black continuous line represents the change over time in probability (95% CI with dashed lines). The horizontal blue line...

Prevalence estimate of H7 Clade, H9 Clade and H11 Clade viruses as a function of time. The line gives a daily prevalence estimate for H7 Clade (A), H9 Clade (B) and (C) H11 Clade viruses (with 95% confidence limits in hatched lines) calculated from the total study period 2002–2008. The distribution of data points is presented as rug plots along the...

Contingency table for phylogenetic HA group independence. (DOCX)

Summary table of the exploration of contingency tables at the HA subtype level for the long lag. (DOC)

Alternative models for depicting the probability that a detected and identified virus belong to a focal clade. Model number one includes all the candidate explanatory variables. In each of models 2–7 one or two explanatory variables are removed from model number one. The AICs of selected models are highlighted in bold. (DOC)

Summary table of the exploration of the contingency tables at the NA subtype level for the short lag. (DOC)

Distribution of days between different detected IAV infections. (TIF)

Prevalence estimate of H1 Clade and H3 Clade viruses as a function of time. The line gives a daily prevalence estimate for H1 Clade (A) and H3 Clade (B) viruses (with 95% confidence limits in dashed lines) calculated from the total study period 2002–2008. The distribution of data points is presented as rug plots along the x-axis. (TIF)

Contingency table for all HA re-infection transitions, rows first infection, columns later infection. (DOCX)

Contingency table for HA re-infections (short lag). (DOCX)

Contingency table for phylogenetic HA clade independence (short lag). (DOCX)

Summary table of the exploration of the contingency tables at the HA clade level for the long lag. (DOC)

Summary table of the exploration of contingency tables at the HA subtype level for the short lag. (DOC)

Summary table of the exploration of the contingency tables at the HA clade level for the short lag. (DOC)