Plague is a zoonotic disease caused by Yersinia pestis, and it is endemic in Madagascar. The plague cycle involves wild and commensal rodents and their fleas; humans are an accidental host. Madagascar is the country where plague burden is the highest. Plague re-emerged in Mahajanga, the western coast of Madagascar, in the 1990s and infected populations in the popular and insalubrious zones. Sanitation is considered a primary barrier to infection by excluding pathogens from the environment and reservoirs. Poor housing and hygiene and proximity to rodents and fleas in everyday life are major and unchanged risk factors of plague. The aim of this study was to measure the impact of sanitation on Yersinia pestis bacteria in human and small mammal reservoirs and flea vectors. This study was conducted on 282 households within 14 neighborhoods. Two sessions of sampling were conducted in 2013 and 2016. Small mammals were trapped inside and around houses using live traps. Fleas, blood and spleen were sampled to detect Y. pestis infection and antibodies and determine the level of plague circulation before and after the installation of sanitation in order to assess the impact of sanitation improvement on inhabitant health. Two major types of housing can be described, i.e., formal and informal (traditional), scattered in all the suburbs. Among the small mammals captured, 48.5% were Suncus murinus, and 70% of houses were infested. After sanitation, only 30% of houses remained infested, and most of them were located around the market. Fleas were mostly Xenopsylla cheopis. Before and after intervention, the overall prevalence of fleas was the same (index 4.5) across the 14 suburbs. However, the number of houses with fleas drastically decreased, and the flea index increased significantly in rodent-infested houses. Rodent abundance also decreased from 17.4% to 6.1% before and after intervention, respectively. A serology study highlights that plague is still circulating in Mahajanga, suggesting that small mammals maintain enzootic plague transmission in the city.

Human cysticercosis caused by Taenia soliun (T. soliun) is endemic in certain areas of Latin America, Asia and Sub-Saharan Africa. Neurocysticercosis (NCC) is mainly diagnosed by neuroimaging, which, in most cases, is unavailable in endemic areas. Due to their high sensitivity and specificity, serological tests such as enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) based on the glycosylated fraction of the cyst CS50 are widely used for the detection of the anti-cysticercus IgG antibodies despite their significant cost and the need of cysticercus material. Given their cost-effectivess and simplicity, immunoassays based on recombinant proteins could provide new alternatives for human cysticercosis diagnosis: such tests would be aimed at screening those people living in remote areas who need further examination. To date, however, no test using recombinant antigens is commercially available. Herein, five recombinant proteins (R14, R18, R93.1, R914.1, and R915.2) were produced, three of which (R93.1, R914.1, and R915.2) were newly identified from the cyst fluid. Evaluation of the diagnostic performance of these recombinant antigens by ELISA was done using sera from 200 epileptic and non-epileptic individuals in comparison with the WB-CS50 as the reference serological method. Recombinant proteins-based ELISA showed a level of diagnostic performance that is inferior than the reference serological method, but similar to that of the native antigen ELISA for human cysticercosis (commonly used for screening). Further optimization of expression conditions is still needed in order to improve proteins solubility and enhance diagnostic performance for human cysticercosis detection. However, this preliminary evaluation of the recombinant antigens has shown their potential valuable use for screening cysticercosis in patients with epilepsy attending dispensaries in remote areas. Future studies should be conducted to evaluate our recombinant antigens in a large group of patients with different stages of NCC, and in correlation with imaging findings.

The present work aims to study the chemical composition and the antimicrobial and toxicological properties of the essential oils (EOs) of Apodocephala pauciflora leaves (LEO) and stem bark (BEO). LEO and BEO were extracted from fresh material by hydrodistillation with a yield of 0.1%. They are light, light yellow, strong smelling and dextrorotatory. Gas chromatography/mass spectrometry (GC/MS) analysis identified 42 components in LEO and 38 in BEO representing 97.54% and 99.44% of the overall composition respectively. In LEO, the major components were α-pinene (27.5%), sabinene (13.62%) and β-pinene (12.0%) and in BEO, α-pinene (34.32%), myrcene (15.1%), sabinene (14.53%). Main components such β-pinene, phellandrene and limonene were common to LEO and BEO but at different rates. However, some components were not common to both EOs: for example, cubenol (5.07%) in LEO was absent in BEO and vice versa humulene (3.91%) in BEO was absent in LEO. Both EOs were effective against all microorganisms tested, including Gram (+) and Gram (-) bacteria and a fungus, with a strain-dependent intensity. BEO was more efficient than LEO. Streptococcus pneumoniae, Pseudomonas aeruginosa, Vibrio fischeri and Candida albicans were the most susceptible. LEO was bacteriostatic against Clostridium perfringens and Candida albicans but bactericidal against the other germs tested, whereas BEO was bactericidal against all germs. With LD50 of 2.48 and 2.34 g/kg body weight, LEO and BEO were slightly toxic to mice by oral route. LEO and BEO could be used as alternatives to synthetic antibiotics against several pathogenic microorganisms.