Geographical and environmental approaches to urban malaria in Antananarivo (Madagascar)

<p>Abstract</p> <p>Background</p> <p>Previous studies, conducted in the urban of Antananarivo, showed low rate of confirmed malaria cases. We used a geographical and environmental approach to investigate the contribution of environmental factors to urban malaria in Antananarivo.</p> <p>Methods</p> <p>Remote sensing data were used to locate rice fields, which were considered to be the principal mosquito breeding sites. We carried out supervised classification by the maximum likelihood method. Entomological study allowed vector species determination from collected larval and adult mosquitoes. Mosquito infectivity was studied, to assess the risk of transmission, and the type of mosquito breeding site was determined. Epidemiological data were collected from November 2006 to December 2007, from public health centres, to determine malaria incidence. Polymerase chain reaction was carried out on dried blood spots from patients, to detect cases of malaria. Rapid diagnostic tests were used to confirm malaria cases among febrile school children in a school survey.</p> <p>A geographical information system was constructed for data integration. Altitude, temperature, rainfall, population density and rice field surface area were analysed and the effects of these factors on the occurrence of confirmed malaria cases were studied.</p> <p>Results</p> <p>Polymerase chain reaction confirmed malaria in 5.1% of the presumed cases. Entomological studies showed <it>An. arabiensis </it>as potential vector. Rice fields remained to be the principal breeding sites. Travel report was considered as related to the occurrence of <it>P. falciparum </it>malaria cases.</p> <p>Conclusion</p> <p>Geographical and environmental factors did not show direct relationship with malaria incidence but they seem ensuring suitability of vector development. Absence of relationship may be due to a lack of statistical power. Despite the presence of <it>An. arabiensis</it>, scarce parasitic reservoir and rapid access to health care do not constitute optimal conditions to a threatening malaria transmission. However, imported malaria case is suggestive to sustain the pocket transmission in Antananarivo.</p

Human plague: An old scourge that needs new answers

Yersinia pestis, the bacterial causative agent of plague, remains an important threat to human health. Plague is a rodent-borne disease that has historically shown an outstanding ability to colonize and persist across different species, habitats, and environments while provoking sporadic cases, outbreaks, and deadly global epidemics among humans. Between September and November 2017, an outbreak of urban pneumonic plague was declared in Madagascar, which refocused the attention of the scientific community on this ancient human scourge. Given recent trends and plague’s resilience to control in the wild, its high fatality rate in humans without early treatment, and its capacity to disrupt social and healthcare systems, human plague should be considered as a neglected threat. A workshop was held in Paris in July 2018 to review current knowledge about plague and to identify the scientific research priorities to eradicate plague as a human threat. It was concluded that an urgent commitment is needed to develop and fund a strong research agenda aiming to fill the current knowledge gaps structured around 4 main axes: (i) an improved understanding of the ecological interactions among the reservoir, vector, pathogen, and environment; (ii) human and societal responses; (iii) improved diagnostic tools and case management; and (iv) vaccine development. These axes should be cross-cutting, translational, and focused on delivering context-specific strategies. Results of this research should feed a global control and prevention strategy within a “One Health” approach

Description de trois nouvelles especes de

Les mâles de trois nouvelles espèces rares de Paractenopsyllus Wagner, 1938, genre endémique de Madagascar, sont décrits. Paractenopsyllus beaucournui, P. oconnori et P. raxworthyi ont été collectés à partir de micromammifères endémiques de Madagascar (excepté un rat noir) et, comme les autres espèces du genre, les biotopes de récolte se situent au sein des forêts des hautes terres centrales ou des massifs du Nord de l'île. Deux des trois espèces décrites ont été récoltées à des altitudes relativement basses pour le genre, à la limite de la zone écoclimatique des hautes terres. Les affinités morphologiques entre ces nouvelles espèces et celles déjà décrites permettent des rapprochements taxonomiques. Une clef de détermination des 20 espèces de Leptopsyllinae malgaches est présentée

Description de trois nouvelles especes de Paractenopsyllus (Siphonaptera : Leptopsyllinae) de Madagascar

Les mâles de trois nouvelles espèces rares de Paractenopsyllus Wagner, 1938, genre endémique de Madagascar, sont décrits. Paractenopsyllus beaucournui, P. oconnori et P. raxworthyi ont été collectés à partir de micromammifères endémiques de Madagascar (excepté un rat noir) et, comme les autres espèces du genre, les biotopes de récolte se situent au sein des forêts des hautes terres centrales ou des massifs du Nord de l'île. Deux des trois espèces décrites ont été récoltées à des altitudes relativement basses pour le genre, à la limite de la zone écoclimatique des hautes terres. Les affinités morphologiques entre ces nouvelles espèces et celles déjà décrites permettent des rapprochements taxonomiques. Une clef de détermination des 20 espèces de Leptopsyllinae malgaches est présentée