Guillaume Constantin de Magny

• Ph.D
• Researcher at Institute of Research for Development

Background Acinetobacter baumannii is a gram-negative, opportunistic pathogen, that is responsible for a wide variety of infections and is a significant cause of hospital-acquired infections. A. baumannii is listed by the World Health Organization (WHO) as a critical priority pathogen because of its high level of antibiotic resistance and the urgen...

Two bacteriophages (phages) of Klebsiella pneumoniae were isolated from sewage water collected from Dakar, Senegal. Phage vKpIN17 belongs to the Przondovirus genus within the Autographiviridae family, with double-stranded DNA genomes, whereas vKpIN18 belongs to the Webervirus genus of the Drexlerviridae family.

sediments in various submerged sampling sites of Dakar. Analysis revealed that sediments were slightly basic in which fine and coarse sands predominated. High percentages of total organic carbon were found sometime above 6%. Higher levels of heavy metal were reported than in previous studies. Chromium and nickel were above the Probable Effect Conce...

Marine pollution around West African big cities is of major concerns. Nevertheless, few attempts have been performed so far particularly on microplastic assessment. We had led first survey targeting microplastic in West African coastal waters (2016); and evaluated on the same sites microbiological contamination as well as marine sediment toxicity a...

1. Présence d’une micro-algue toxique sur la presqu’île de Dakar. 2. Cette micro-algue, relâche des toxines - analogues de la toxine palytoxine - qui ont des effets sur la santé humaine avec des symptômes variables qui peuvent s’apparenter à la grippe saisonnière. 3. Faible connaissance de cette toxine par les services de santé et de la médecine gé...

Every year, cholera affects 1.3–4.0 million people worldwide with a particularly high presence in Africa. Based on recent studies, effective targeting interventions in hotspots could eliminate up to 50% of cases in Sub-Saharan Africa. Those interventions include Water, Sanitation, and Hygiene (WASH) programs whose influence on cholera control, up t...

Background The countries of West Africa are largely portrayed as cholera endemic, although the dynamics of outbreaks in this region of Africa remain largely unclear. Methodology/Principal findings To understand the dynamics of cholera in a major portion of West Africa, we analyzed cholera epidemics from 2009 to 2015 from Benin to Mauritania. We co...

Map of Africa indicating the localization of sites visited. A zoom on the Guinea/Sierra Leone region (blue), southern Ivory Coast (purple), southern Ghana (red), and southern Togo and Benin (orange) are shown. In the Ivory Coast box, Sud Comoé (Ivory Coast) is indicated in pink and Jomoro District (Ghana) is indicated in yellow. In the Ghana box, V...

Field visit details and protocol. (DOCX)

Evolution of cholera cases in Ghana in 2010. Weekly cholera cases reported in Eastern, Central, and Ashanti Region are shown. The suspected cholera cases reported are indicated on the Y-axis and the weeks are indicated on the X-axis. (TIF)

Weekly number of suspected cholera cases in Benin, by commune, from 2011 to 2014. The suspected cholera cases reported are indicated on the Y-axis and the weeks are indicated on the X-axis. The communes declaring cholera cases are indicated to the right of the corresponding histogram. (TIF)

Weekly number of suspected cholera cases in Togo, by district, and in Lomé from 2013 to 2014. The top two histograms show weekly cholera cases by district in 2013 and 2014. The upper two histograms weekly cholera cases in Lomé in 2013 and 2014. Suspected cholera cases reported are indicated on the Y-axis and the weeks are indicated on the X-axis. T...

The epidemic populations, isolate IDs, and PCR amplicon size of each allele corresponding to each MLVA type. The number of isolates corresponding to each MLVA type is indicated on the right. The environmental isolates are indicated with an asterisk (MLVA type column). (DOCX)

Annual cholera cases reported in the study region from 2009 to 2015 and major identified events involved in the westward wave of epidemics from 2011 to 2014. Key events and observations involved in cholera epidemics: (1) events of V. cholerae importation between Benin, Togo, and Ghana; (2) the 2011 cholera epidemic in Ivory Coast broke out followin...

Vibrio cholerae O1 is the causative agent of cholera with classical and El Tor, two well-established biotypes. In last 20 years, hybrid strains of classical and El Tor and variant El Tor which carry classical ctxB have emerged worldwide. In 2004–2005, Senegal experienced major cholera epidemic with a number of cases totalling more than 31719 with a...

n

Significance Big data and, in particular, mobile phone data are expected to revolutionize epidemiology, yet their full potential is still untapped. Here, we take a significant step forward by developing an epidemiological model that accounts for the spatiotemporal patterns of human mobility derived by directly tracking properly anonymized mobile ph...

A few decades ago, Senegal was a model for the sub-region with a drainage system connected to wastewater treatment plant. These infrastructures have been deteriorated and the country (especially the capital) is experiencing rapid population growth, urban planning and industrial development that are difficult to control. Industrial, fishing, agr...

Human mobility is one of the most important mechanisms of disease spread between different human communities. Thus, the accurate description of human mobility patterns is the key to high- quality spatially explicit epidemiological models. Mobile phone call records have been shown to contain precious information about the location of users over time...

To determine when risk for Buruli ulcer is highest, we examined seasonal patterns in a highly disease-endemic area of Cameroon during 2002-2012. Cases peaked in March, suggesting that risk is highest during the high rainy season. During and after this season, populations should increase protective behaviors, and case detection efforts should be int...

Technical Appendix. Additional materials, methods, and results for analysis of seasonal patterns of Buruli ulcer incidence, central Africa, 2002–2012.

Du point de vue historique, la compréhension de la dynamique des maladies transmissibles relève des domaines de l'épidémiologie et plus spécifiquement de l'infectiologie. La prise en compte des processus physiques, écologiques ou évolutifs, qui interviennent à des échelles de temps et d'espace plus larges, a récemment démontré sa pertinence.

Background During the last century, WHO led public health interventions that resulted in spectacular achievements such as the worldwide eradication of smallpox and the elimination of malaria from the Western world. However, besides major successes achieved worldwide in infectious diseases control, most elimination/control programs remain frustratin...

Understanding the seasonal emergence and reemergence of cholera is challenging due to the complex dynamics of different protagonists. The abundance of Vibrio cholerae, the causative agent of cholera and a natural inhabitant of aquatic environments, fluctuates according to abiotic, and biotic factors. Among the biotic factors, the zooplankton commun...

Vibrio parahaemolyticus is a leading cause of seafood-related gastroenteritis and is also an autochthonous member of marine and estuarine environments worldwide. One-hundred seventy strains of V. parahaemolyticus were isolated from water and plankton samples collected along the Georgian coast of the Black Sea during 28 months of sample collection....

Cholera is an acute diarrheal illness caused by Vibrio cholerae and occurs as widespread epidemics in Africa. In 2005, there were 31,719 cholera cases, with 458 deaths in the Republic of Senegal. We retrospectively investigated the climate origin of the devastating floods in mid-August 2005, in the Dakar Region of Senegal and the subsequent outbrea...

Daily rainfall country mean annually accumulated anomaly between 2002 and 2005. Mean is represented by the black line, the grey surface represents the (+/−) standard deviation around the mean. (TIF)

Annual cholera morbidity in Senegal and its frontline countries from 1970 to 2010 (source WHO) (DOC)

Cross-correlation diagram between cholera cases time-series and rainfall for Dakar between May 10 and December 31, 2005. Lag time unit is days. (TIF)

Vibrio vulnificus, an estuarine bacterium, is the causative agent of seafood-related gastroenteritis, primary septicemia, and wound infections worldwide. It occurs as part of the normal microflora of coastal marine environments and can be isolated from water, sediment, and oysters. Hindcast prediction was undertaken to determine spatial and tempora...

Vibrio cholerae, a bacterium autochthonous to the aquatic environment, is the causative agent of cholera, a severe watery, life-threatening diarrheal disease occurring predominantly in developing countries. V. cholerae, including both serogroups O1 and O139, is found in association with crustacean zooplankton, mainly copepods, and notably in ponds,...

Cholera remains a major public health threat in many developing countries around the world. The striking seasonality and annual recurrence of this infectious disease in endemic areas remain of considerable interest to scientists and public health workers. Despite major advances in the ecological and microbiological understanding of Vibrio cholerae,...

Androdioecy is a sexual system in which males co-occur with hermaphrodites, which have both male and female function. Stable androdioecy is rare in nature, and theory suggests that it requires that males sire more than twice as many offspring as hermaphrodites. In several members of the olive family (Oleaceae), androdioecy occurs with higher freque...

Vibrio cholerae, the causative agent of cholera, is a naturally occurring inhabitant of the Chesapeake Bay and serves as a predictor for other clinically important vibrios, including Vibrio parahaemolyticus and Vibrio vulnificus. A system was constructed to predict the likelihood of the presence of V. cholerae in surface waters of the Chesapeake Ba...

Vibrio cholerae, the causative agent of cholera, is naturally present in the environment and autochthonous to coastal and estuarine ecosystems. V. cholerae is associated with copepods for its survival and multiplication in the natural environment. Changes in the density of its reservoir may result in modification of the bacterial population size in...

Is it possible to omit parasites when studying free-living organisms? The answer is clearly no! Parasites have evolved independently in numerous animal lineages, and now make up a considerable proportion of the biodiversity of life. Ecologists, epidemiologists, conservationists and evolutionary biologists are increasingly aware of the universal sig...

The causative agent of cholera, Vibrio cholerae, has been shown to be autochthonous to riverine, estuarine, and coastal waters along with its host, the copepod, a significant member of the zooplankton community. Temperature, salinity, rainfall and plankton have proven to be important factors in the ecology of V. cholerae, influencing the transmissi...

Meningococcal meningitis (MM) is still a huge threat in the African meningitis belt. To fight against epidemics, a strengthened health information system, based upon weekly collected data, was set up in Mali. We aimed to study the spatio-temporal dynamics of MM in this country between 1992 and 2003. We were first interested in the impact of populat...

In the current context of global infectious disease risks, a better understanding of the dynamics of major epidemics is urgently needed. Time-series analysis has appeared as an interesting approach to explore the dynamics of numerous diseases. Classical time-series methods can only be used for stationary time-series (in which the statistical proper...

Meningococcal meningitis (MM) represents an important public health problem especially in the "meningitis belt" in Africa. Although seasonality of epidemics is well known with outbreaks usually starting in the dry season, pluri-annual cycles are still less understood and even studied. In this context, we aimed at study MM cases time series across 9...

The relationship between cholera and climate was explored in Africa, the continent with the most reported cases, by analyzing monthly 20-year cholera time series for five coastal adjoining West African countries: Côte d'Ivoire, Ghana, Togo, Benin and Nigeria. We used wavelet analyses and derived methods because these are useful mathematical tools t...

IntroductionThe Interactions Between Human Populations and Natural SystemsDynamic Properties of Microbes, Their Hosts and the EnvironmentThe Ecology of Infectious Diseases in PracticeConclusion and Suggested Research PerspectivesSummaryAcknowledgmentsReferences

Cholera, an acute diarrheal illness, is caused by infection of the intestine with the bacterium Vibrio cholerae after ingestion of contaminated water or food. The disease had disappeared from most of the developed countries in the last 50 years, but cholera epidemics remain a major public health problem in many developing countries, most often loca...

Les modèles linéaires généralisés (GLIM) sont une généralisation bien connue de modèle de régression linéaire dans les cas où la réponse est une variable discrète ou que le modèle est différent des modèles linéaires standards. Les modèles linéaires généralisés utilisés le plus souvent sont des modèles de régression logistiques pour des données bina...

Cholera remains a major public health problem with significant mortality, and numerous re-emergences have been observed in the last decade in many developing countries. Previous analyses have suggested a complex process for cholera disease emergence and spread, particularly related to environmental factors associated to aquatic habitats. To disenta...

Diffusion du document : INRA Documentation de Centre, Domaine de Duclos, 97170 Petitt-Bourg (Guadeloupe, France) Diplôme : DEA