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The article presents an abstract of the paper "Remarkable morphological traits in Eulemur rubriventer (Lemuridae) revealed by elliptical Fourier analysis of the cranial and mandabular shape and by quantification of cranial areas," by H. Raveloson and colleagues, to be presented at the 21st Congress of the International Society of Primatological Society in Entebbe, Uganda on June 25-30, 2006.

Background: Plague, caused by the bacterium Yersinia pestis, remains an important disease in Madagascar, where the oriental rat flea, Xenopsylla cheopis, is a primary vector. To control fleas, synthetic pyrethroids (SPs) have been used for >20 years, resulting in resistance in many X. cheopis populations. The most common mechanisms of SP resistance are target site mutations in the voltage-gated sodium channel (VGSC) gene. Methodology/Principal findings: We obtained 25 collections of X. cheopis from 22 locations across Madagascar and performed phenotypic tests to determine resistance to deltamethrin, permethrin, and/or dichlorodiphenyltrichloroethane (DDT). Most populations were resistant to all these insecticides. We sequenced a 535 bp segment of the VGSC gene and identified two different mutations encoding distinct substitutions at amino acid position 1014, which is associated with knockdown resistance (kdr) to SPs in insects. Kdr mutation L1014F occurred in all 25 collections; a rarer mutation, L1014H, was found in 12 collections. There was a significant positive relationship between the frequency of kdr alleles and the proportion of individuals surviving exposure to deltamethrin. Phylogenetic comparisons of 12 VGSC alleles in Madagascar suggested resistant alleles arose from susceptible lineages at least three times. Because genotype can reasonably predict resistance phenotype, we developed a TaqMan PCR assay for the rapid detection of kdr resistance alleles. Conclusions/Significance: Our study provides new insights into VGSC mutations in Malagasy populations of X. cheopis and is the first to report a positive correlation between VGSC genotypes and SP resistance phenotypes in fleas. Widespread occurrence of these two SP resistance mutations in X. cheopis populations in Madagascar reduces the viability of these insecticides for flea control. However, the TaqMan assay described here facilitates rapid detection of kdr mutations to inform when use of these insecticides is still warranted to reduce transmission of plague. Author summary: In Madagascar, the Oriental rat flea Xenopsylla cheopis is the primary vector of Yersinia pestis, which causes plague. This flea has been reported to be resistant to insecticides used for vector control. The objective of this study was to examine the target site mutations in the voltage-gated sodium channel (VGSC) gene in X. cheopis populations sampled throughout the island and previously tested for synthetic pyrethroid (SPs) susceptibility. Two widespread mutations associated with knock-down resistance (kdr) to SPs were identified, and a significant relationship between the frequency of kdr alleles and the SP resistance phenotype was revealed. The results raise concerns about the overall efficacy of SPs for controlling Yersinia pestis transmission by X. cheopis in Madagascar. [ABSTRACT FROM AUTHOR]

Madagascar is known for its high endemism and as many as 90% of this unique diversity are forest‐dwellers. Unfortunately, the forest cover of Madagascar is decreasing at an alarming rate. This decrease can also affect aquatic insects, but our knowledge on aquatic insect diversity and distribution on Madagascar are limited. Although the eastern rainforests are considered the most diverse, the Central Highlands of Madagascar also harbors unique microendemic fauna but has been less studied. Here, we analyze the aquatic Adephaga beetle fauna of three remaining protected forests of the Central Highlands. Diversity, abundance, and uniqueness are compared between and within natural forests and surrounding grasslands. At least 15 undescribed species were found, highlighting the Central Highlands as an important area for endemism. The natural forests and the surrounding grasslands differed significantly in species assemblages. Interestingly, the three remaining forests differed in their assemblages with the geographically more distant Manjakatompo Ankaratra having the most unique fauna but also the highest altitude span. By contrast, the species composition was similar between the peripheral zones of each of the three remaining forests. The similarity of the fauna in the peripheral open habitats illustrates how some local forest endemics are replaced with widespread generalists in degraded habitats. Our study shows that the remaining forests of the Central Highlands of Madagascar are important refuges of unique fauna at high risk of extinction. [ABSTRACT FROM AUTHOR]

Rice blast, caused by the filamentous ascomycete Pyricularia oryzae, is one of the most devastating diseases of rice. Four genetic clusters were previously identified, and three have a large geographic distribution. Asia is the center of diversity and the origin of most migrations to other continents, and sexual reproduction persisted only in the South China-Laos-North Thailand region, which was identified as the putative center of origin of all P. oryzae populations on rice. Despite the importance of rice blast disease, little is known about the diversity and the population structure of the pathogen in Africa (including Madagascar). The present study was intended to describe the structure of African populations of P. oryzae and identify the relationship between African and worldwide genetic clusters. A set of 2,057 strains (937 African and 1,120 Madagascan strains) were genotyped with 12 simple sequence repeat markers to assess the diversity and the population structure of P. oryzae. Four genetic clusters were identified in Africa and Madagascar. All four clusters previously identified are present in Africa. Populations from West Africa, East Africa, and Madagascar are highly differentiated. The geographic structure is consistent with limited dispersion and with some migration events between neighboring countries. The two mating types are present in Africa with a dominance of Mat1.2, but no female-fertile strain was detected, supporting the absence of sexual reproduction on this continent. This study showed an unsuspected high level of genetic diversity of P. oryzae in Africa and suggested several independent introductions. [ABSTRACT FROM AUTHOR]

Wild aye-ayes (Daubentonia madagascariensis) are notoriously difficult to study due to their solitary and nocturnal nature. While research is starting to elucidate the behaviors of wild adult aye-aye, an understanding of behaviors in young aye-ayes is still lacking. We studied the behavioral development of two male aye-aye subadults in Kianjavato, Madagascar from June 2015 to October 2017 and October 2017 to December 2019, and two male offspring in Torotorofotsy, Madagascar, from August 2016 to December 2017 and September 2018 to May 2020. We then compared this information to previous studies on captive infant development. Wild infant aye-ayes first emerged from the nest between two and three months old. Traveling between trees occurred between four and four and a half months old. First attempts at foraging for invertebrates in a woody substrate occurred between five and eight months. Though nursing was rarely observed, the event was witnessed as late as 17 months for one aye-aye. The earliest solo nesting occurred at 18 and a half months of age, and the latest at 23 months old. As with other primates, wild aye-ayes develop more slowly than their captive counterparts. We conclude that their protracted life history is likely associated with their percussive foraging behaviors and importance of invertebrates in their diet. [ABSTRACT FROM AUTHOR]

Several dozen stones of an ordinary chondrite meteorite fell in and around the town of Benenitra in southwestern Madagascar during the early evening of 27 July 2018, minutes after a widely observed meteor fireball (bolide) transit and detonation. The event was confirmed by low-frequency infrasound recordings received at ~17h15 UTC (Coordinated Universal Time; 19h15 local time) at the Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) infrasound station I33MG near Antananarivo, 542 km northnortheast of Benenitra. An energy release equivalent to 2.038 kt of TNT was calculated from the infrasound signals. Seismograph readings at the SKRH station 77 km north-northwest of Benenitra recorded a twostage signal consistent with the arrivals of an initial air-coupled ground wave at 16h48:08 UTC and a stronger pulse at 16h49:22 UTC linked directly to the atmospheric pressure wave. The infrasound and seismic signal arrival times suggest that the bolide entry and detonation occurred at approximately 18h46 local time (16h46 UTC), entry was from the northwest, and the detonation hypocentre was located within ~20 km of Benenitra. Despite meteorite debris being found among buildings within Benenitra, there was no damage to structures or injuries reported. Eyewitness accounts and photographic records indicate that approximately 75 mostly intact stones were collected; however, the remoteness of the area, the rugged nature of the terrain and sales of fragments to meteorite collectors have limited scientific analysis of the fall and the extent of the strewn field. The total mass of recovered stones is estimated at between 20 kg and 30 kg, with one fragment of 11.2 kg and several of ~1 kg. Petrographic and mineral chemical analyses indicate that the stones belong to the L6 class of ordinary chondrites. Cosmogenic radionuclide analysis confirms that the fall is linked to the bolide event. The name Benenitra has been officially accepted by the Meteoritical Bulletin Database. [ABSTRACT FROM AUTHOR]

Revealing belowground-aboveground relationships (BAR) is essential to drive ecological processes to address agriculture dysfunctions, especially in the management of aboveground plant diseases. Earthworms are one of the most important soil organisms involved in BAR, and silicon (Si) has been identified as a crucial element regulating aboveground plant health. How earthworm-Si interactions induce BAR in poor- and rich-nutrient soil contexts is still poorly understood, despite a growing interest in agricultural sustainability. We investigated the potential of BAR induced by the earthworm-silicon interaction to control the severity of rice blast disease in a Ferralsol in Madagascar, with or without NPK fertilization. We conducted a greenhouse microcosm experiment in which we manipulated the presence of the endogeic earthworm Pontoscolex corethrurus and the fungus Pyricularia oryzae in a Ferralsol supplied or not with Si and fertilized with macronutrients (nitrogen, phosphorus and potassium, i.e., NPK). After eight weeks of growth, plant biomass, nutrition and disease severity were measured. Our results validated the hypothesis that a dual treatment of earthworm inoculation and Si fertilization in a nutrient-poor tropical soil confers a higher tolerance of rainfed rice to P. oryzae , in comparison with treatments with only earthworms or Si, providing the optimal agronomic balance between a gain in biomass (and nutrition) and a reduction in disease severity. The supply of macronutrients altered this positive BAR by favouring the phenomenon of N-induced susceptibility. The aboveground plant C:N ratio of 15 is a threshold below which any increase in N per C unit likely enhances blast disease. The role of belowground interactions to counteract agricultural dysfunctions is supported by our study. To accomplish ecological intensification and provision of ecosystem services such as disease regulation, our findings recommend replacing excessive use of macronutrient fertilizer with sustained agricultural practices promoting the development of earthworm populations, such as organic matter inputs, superficial or no tillage, and the use of cover crops or conservation agriculture. Unlabelled Image • Earthworm and Si addition confer a higher tolerance of rice to blast disease than NPK. • Without NPK, earthworms improve plant growth without increasing disease severity. • With NPK, earthworms and especially Si decrease disease severity. • Plant C:N ratio of 15 appears as a threshold for the development of blast disease. • Earthworms and Si provide the optimal balance between biomass gain and disease severity. [ABSTRACT FROM AUTHOR]

On upland soils in tropical Africa, common production constraints of rice and maize on smallholder farms are poor soil fertility—resulting from soil erosion and nutrient depletion—and infestation by witchweeds (Striga spp.). In Madagascar where these crops are often grown in rotation, combining legume cover crops with no-till and crop residue mulching—labelled conservation agriculture (CA)—may address these problems. Previously, it was shown that CA practices contribute to steep reductions in Striga asiatica infection. In the current study, a 4-year field experiment was conducted to test, for the first time, the hypothesis that CA practices also contribute to crop yield and soil improvements under Striga-infested conditions. The conventional mono-crop rice–maize rotation practice, involving seasonal tillage and crop residue removal, was compared to three rice–maize rotation systems following CA practices, each with a different legume cover crop option: (1) two short-cycle annual species, cowpea (Vigna unguiculata) and mucuna (Mucuna pruriens); (2) a long-cycle annual, ricebean (Vigna umbellata); and (3) a perennial, stylosanthes (S. guianensis). Rice yields, as well as yield variability, generally increased by changing from the conventional to a CA practice, and maize yields were variable and low in particular under the CA practices. CA practices significantly reduced soil displacement by rainwater runoff and increased soil nitrogen and pH levels (0–20 cm depth), in particular with stylosanthes as cover crop, but did not result in a significant change in soil organic carbon concentration. Rice yields correlated negatively with Striga asiatica plant numbers in years with moderate infection levels. This is the first study that shows mixed outcomes from CA practices in tropical cereal rotation systems on degraded, Striga-infested soils, and subsequent entry points for system improvements. Suggested improvements include judicious cover crop management, complementary fertilizer applications and selection of competitive, resistant and adapted crop varieties. [ABSTRACT FROM AUTHOR]

Background: In developing countries, knowledge of antimicrobial resistance patterns is essential to define empirical therapy. Methodology: All the surgery and intensive care wards of two hospitals in Antananarivo were included to study the antimicrobial susceptibility of the pathogenic bacteria causing nosocomial infections. A repeated cross-sectional survey was conducted between September 2006 and March 2008, one day per week. Isolates were identified using classical methods, and resistance to antibiotics was assessed according to the recommendations of the Antibiogram Committee of the French Microbiology Society. Results: Clinical specimens from 706 from 651 patients were collected. Of the 533 bacterial pathogens, 46.7% were Enterobacteriaceae, 19.3% were Staphylococcus aureus, and 19.1% were pathogens from the hospital environment (Pseudomonas aeruginosa and Acinetobacter baumannii).Frequencies of resistance were high, particularly in Enterobacteriaceae; however, the rate of Staphylococcus aureus isolates resistant to oxacillin (13.6 %) was moderate and all these isolates were susceptible to glycopeptids. The percentages of isolates susceptible to ceftazidim were 81.8% for E. coli, 60.9% for Klebsiella, and 52.5% for Enterobacter spp. Resistance to third-generation cephalosporins was due to extended spectrum betalactamases (ESBL). Multivariate analysis showed that diabetes (adjusted OR: 3.9) and use of an invasive procedures (adjusted OR: 3.5) were independent risk factors for resistance to third-generation cephalosporins. Conclusion: A nationwide surveillance programme is needed to monitor the microbial trends and antimicrobial resistance in Madagascar. [ABSTRACT FROM AUTHOR]

Madagascar presents a large heterogeneity in terms of climate and altitude, which explains the uneven spread of malaria throughout the island. The capital, Antananarivo, counts more than one million inhabitants, altitude between 1250 and 1470 m, in an area where the transmission is low but malaria may cause deadly epidemic outbreaks. Numerous malaria cases are reported, without biological confirmation, and reliable data about urban malaria transmission are lacking. The " Institut Pasteur de Madagascar" together with the Malagasy Ministry of Health performed in 2003 a study about malaria transmission in Antananarivo. A prevalence survey of malaria among fever syndromes, with data collected from 43 urban dispensaries, showed that confirmed malaria cases represented only 2% of the total fever cases (15 cases out of 779 fever syndromes). The vast majority was imported from costal areas (13 cases out of 15), where malaria is hyperendemic. However, a local urban transmission was found for two patients and five other subjects identified during a proximity survey. Vectors A. arabiensis and A. funestus were found inside the patient houses, located in close proximity of flooded rice fields. Genetic analysis of P. falciparum strains allowed to distinguish three genotypes, aggregated by house. The analysis of parasite genome polymorphism proves here its validity for epidemic surveys in areas where malaria is unstable, with no premunition in the local urban population.

Chloroquine has been used as a first line drug to treat uncomplicated malaria cases during the last five decades in Madagascar and in the Comoros Union. The four plasmodial species known to infect humans occur on Madagascar Island. Chloroquine-resistant malaria cases, sometimes only suspected from presumptive malaria cases, have been reported in both countries. Thus, to redefine a strategy and a policy to cure malaria, there is a need to get relevant and updated data. In December 1999, the Madagascan Ministry of Health and the Institut Pasteur de Madagascar formed a network named RER for malaria resistance surveillance. In 2000 and 2001, 18 study sites (17 throughout Madagascar and 1 in Comoros) joined this network. Health-care workers were trained mainly for malaria diagnosis through the use of blood smear examination and for malaria case management. To alleviate the lack of competent medical teams within the health centres, and for technical and logistic reasons, as part of the network activities, it was decided to start with in vitro tests to assess the sensitivity of P.falciparum isolates to chloroquine by means of the isotopic method. Parasitized blood samples were collected from consenting patients. P.falciparum isolates were more predominant (989/1,036). Out of the 564 tests done, 432 (76.6%) could be assessed. Results demonstrated that 94.3% (381/404) of the Madagascan P.falciparum isolates were susceptible to chloroquine. In contrast, chloroquine-resistant isolates were prevalent in Comoros (8/28). The network set-up is presented. The usefulness of the in vivo approach and of the in vitro investigations (chemosusceptibility test and screening of mutations accounting for resistance to chloroquine) to monitor the emergence and the dissemination of chloroquine-resistant parasites is discussed.

To alleviate the insufficient number of experienced medical teams invited to and accepting to monitor the effectiveness of drugs prescribed to patients with a diagnosis of uncomplicated malaria and to insure the surveillance of the susceptibility of P. falciparum to current antimalarials used in Madagascar, there is a need to draw a feasible study protocol carefully discussed with them. We carried out a preliminary study in two rural areas and assessed the efficacy of sulfadoxine-pyrimethamine (SP) for curing uncomplicated P. falciparum malaria, with a simplified protocol based on the principle of observational study. A single dose of SP was given on day 0 with paracetamol. The persons to whom the drugs were administered accepted two other interventions of one member of the medical teams on day 14 and day 28. Nineteen patients, 3-63 years old, fulfilled the follow-up. The efficacy of this combination was noted for the 19 persons. Our results show that P. falciparum strains are susceptible to SP. Since SP will be used in intermittent preventive treatment in pregnant women in Madagascar, one way to delay the occurrence of SP resistant parasites will be (a) to avoid massive use of SP for the non pregnant persons and (b) to monitor susceptibility of P. falciparum to SP as part of pilot studies using standard WHO protocol (which is not really easy for most of the peripheral health facilities--with the follow-up procedures with clinical examination and parasitological control at Days 0, 1, 2, 3, 7, 14, 21 and 28), and routinely with simplified protocol such as the analytical observational study illustrated in this present study. Limit and advantage of observational study are discussed.

For malaria vector control in Madagascar, 10 WP (lambda-cyhalothrin 10% wettable powder) was compared with DDT 75% WP for house-spraying, from November 1997 to September 1998. This study was implemented at the fringe of the malaria epidemic zone, in villages on western slopes of the central highlands, outside the area covered for the past five years by routine DDT house-spraying (OPID). Four types of treatment were compared in different areas: 1) DDT 2 g ai/m2 and 2) lambda-cyhalothrin 30 mg ai/m2 in previously unsprayed villages, 3) no intervention (control); 4) yearly DDT spraying (OPID fifth cycle). To investigate the malariological impact of spraying, cross-sectional surveys of the village populations were performed in each study area at intervals of two months, before and after spraying. In the newly sprayed areas, from December to June, malaria indices decreased by 62% in the ICON area and 44% in the DDT area, whereas in the unsprayed village malaria increased by 32% during the same season. There was a similar decrease in the number of gametocyte carriers in the newly sprayed areas. Active malaria case detection among febrile individuals was performed fortnightly in each village outside the OPID area. Results showed decreased malaria incidence from February (two months post-spraying) in the sprayed villages, despite the rainy season, whereas in the unsprayed area the decline occurred only after the main transmission season. This study demonstrated that, parasitologically as well as entomologically, house-spraying with residual insecticide (DDT or ICON) was an effective method for controlling malaria on the western fringes of the Madagascar highlands epidemic zone. Both products were effective, but ICON had slightly better impact than DDT, i.e. more reduction of malaria indices and of vector longevity, less irritancy of mosquitoes. For best results in this area of transition between stable and unstable malaria, we recommend earlier annual spraying (as soon as November) and extension of the OPID barrier towards western and northern slopes of the Plateau.

For malaria vector control in Madagascar, the efficacy of lambda-cyhalothrin 10% wettable powder (ICON 10 WP) was compared with DDT 75% WP for house-spraying. This evaluation was conducted from November 1997 to September 1998 in highland villages of Vakinankaratra Region, at the fringe of the malaria epidemic zone, outside the zone covered by routine DDT house-spraying (Opération de pulvérisation intro-domiciliaire de DDT: OPID zone). Treatments were compared by house-spraying in four areas: 1) application of DDT 2g ai/m2 and 2) lambda-cyhalothrin 30 mg ai/m2 in previously unsprayed villages; 3) no intervention (control); 4) OPID 5th cycle of DDT 2g ai/m2. The prevalent vector Anopheles funestus almost disappeared from both the DDT and ICON sprayed areas, whereas in the unsprayed (control) area An. funeslus density went up to 60 females per room in April and there were two seasonal peaks of malaria transmission in January and March (see following paper). In the area sprayed with ICON, the parous rate of An. funestus decreased from 47% pre-spray to 39% six months post-spraying, while the parous rate increased in DDT-sprayed area (from 57% pre-spray to 64% six months post-spray). Bioassays of An. funestus on treated walls, six months post-spray, gave mortality rates of 100% on DDT and 90% on ICON. Conversely, ICON appeared to be more effective than DDT on thatched roofs (66% versus 100%, respectively, six months post-spray). In areas sprayed with DDT or ICON the density of An. arabiensis were little affected. This study demonstrated that, under equivalent conditions, both DDT and lambda-cyhalothrin were effective in reducing malaria transmission on the western fringes of the malaria epidemic zone of the malagasy highlands, with a residual effect lasting at least for six months. Lambda-cyhalothrin appeared to be more effective than DDT in reducing the longevity of malaria vectors. In addition to efficacy, the choice of insecticide for malaria vector control should take into account their acceptability by human populations and their toxicity and persistence in the environment.

The central highlands in Madagascar are characterized by an unstable occurrence of malaria with the risk of sporadic outbreaks. In major parts of the region DDT indoor spraying campaigns have been carried out from 1993 to 1998. This strategy was in 1999 replaced by another anti-vector intervention program targeting residual foci as detected by a surveillance and early warning system. This system is based on monitoring of presumptive malaria cases in the communities by which the number of presumptive cases exceeded a defined warning threshold value per month. The system was in the follow-up period shown to be very sensitive to variation of the coverage of anti-vector interventions: the number of presumptive cases decreased in the villages in which indoor spraying had been carried out and a minor increase was observed in those villages, where indoor spraying has been suspended. An increase of malaria cases was observed in 44 (20.8%) out of 212 study sites in the same period. The increase was in particular predominant in areas at lower attitude at the outer zones of the central highlands.

The Malagashy national malaria control programme ('Programme National de Lutte contre le Paludisme', PNLP) has been developing, since 1996, an epidemiological early warning system for malaria epidemics in the Central Highlands with the support of the Italian Development Cooperation. The system is based on the monitoring of malaria morbidity (clinical diagnosis) in 536 peripheral health centres (CSB) of the Highlands. The intervention area corresponds to 27 districts of the Antananarivo and Fianarantsoa provinces (4.7 million inhabitants) and spans around 100,000 square km. For each CSB a monthly warning threshold, defined as the 1993-1996 monthly mean number of malaria cases plus two standard deviations, was established. Three levels of epidemic alert have been defined according to the number of times the cases of presumptive malaria surpassed the threshold and according to the reported presence of severe malaria cases. The surveillance system relies also on the monitoring, in district hospitals of the Highlands, of the Plasmodium falciparum infection rate among clinically diagnosed malaria cases. A total of 185,589 presumptive malaria cases, corresponding to a 42/1000 malaria incidence, were recorded in 1997 by the surveillance system. During the same year 184 alerts of 2nd degree were reported. During 1998 173,632 presumptive malaria cases corresponding to a 38/1000 incidence were reported and 207 alerts of 2nd degree were detected; 75 of these alerts were investigated with ad hoc surveys and 3 initial malaria epidemics identified and controlled. Out of 6884 presumptive malaria cases diagnosed in the district hospitals during 1997-1998, only 835 (12.1%) have been confirmed by microscopy (P. falciparum 81.7%, P. vivax 15.0%, P. malariae 2.5%, P. ovale 0.2%, mixed infections 0.6%); 22.4% of these infections were imported cases from coastal endemic areas. The efficiency of the system in monitoring the trend of malaria morbidity and in the rapid detection and response to malaria epidemics is still being evaluated.