Thermal tolerance of mosquito eggs is associated with urban adaptation and human interactions

Climate change is expected to profoundly affect mosquito distributions and their ability to serve as vectors for disease, specifically with the anticipated increase in heat waves. The rising temperature and frequent heat waves can accelerate mosquito life cycles, facilitating higher disease transmission. Conversely, higher temperatures could increase mosquito mortality as a negative consequence. Warmer temperatures are associated with increased human density, suggesting a need for anthropophilic mosquitoes to adapt to be more hardy to heat stress. Mosquito eggs provide an opportunity to study the biological impact of climate warming as this stage is stationary and must tolerate temperatures at the site of female oviposition. As such, egg thermotolerance is critical for survival in a specific habitat. In nature, Aedes mosquitoes exhibit different behavioral phenotypes, where specific populations prefer depositing eggs in tree holes and prefer feeding non-human vertebrates. In contrast, others, particularly human-biting specialists, favor laying eggs in artificial containers near human dwellings. This study examined the thermotolerance of eggs, along with adult stages, for Aedes aegypti and Ae. albopictus lineages associated with known ancestry and shifts in their relationship with humans. Mosquitoes collected from areas with higher human population density, displaying increased human preference, and having a human-associated ancestry profile have increased egg viability following high-temperature stress. Unlike eggs, thermal tolerance among adults showed no significant correlation based on the area of collection or human-associated ancestry. This study highlights that the egg stage is likely critical to mosquito survival when associated with humans and needs to be accounted when predicting future mosquito distribution.

Extensive variation and strain-specificity in dengue virus susceptibility among African Aedes aegypti populations

African populations of the mosquito Aedes aegypti are usually considered less susceptible to infection by human-pathogenic flaviviruses than globally invasive populations found outside Africa. Although this contrast has been well documented for Zika virus (ZIKV), it is unclear to what extent it is true for dengue virus (DENV), the most prevalent flavivirus of humans. Addressing this question is complicated by substantial genetic diversity among DENV strains, most notably in the form of four genetic types (DENV1 to DENV4), that can lead to genetically specific interactions with mosquito populations. Here, we carried out a survey of DENV susceptibility using a panel of seven field-derived Ae. aegypti colonies from across the African range of the species and a colony from Guadeloupe, French West Indies as non-African reference. We found considerable variation in the ability of African Ae. aegypti populations to acquire and replicate a panel of six DENV strains spanning the four DENV types. Although African Ae. aegypti populations were generally less susceptible than the reference non-African population from Guadeloupe, in several instances some African populations were equally or more susceptible than the Guadeloupe population. Moreover, the relative level of susceptibility between African mosquito populations depended on the DENV strain, indicating genetically specific interactions. We conclude that unlike ZIKV susceptibility, there is no clear-cut dichotomy in DENV susceptibility between African and non-African Ae. aegypti. DENV susceptibility of African Ae. aegypti populations is highly heterogeneous and largely governed by the specific pairing of mosquito population and DENV strain.

Low humidity enhances Zika virus infection and dissemination in Aedes aegypti mosquitoes

As climate change alters Earth's biomes, it is expected the transmission dynamics of mosquito-borne viruses will change. While the effects of temperature changes on mosquito-virus interactions and spread of the pathogens have been elucidated over the last decade, the effects of relative humidity changes are still relatively unknown. To overcome this knowledge gap, we exposed Ae. aegypti females to various low humidity conditions and measured different components of vectorial capacity such as survival, blood-feeding rates, and changes in infection and dissemination of Zika virus. Survival decreased as the humidity level decreased, while infection rates increased as the humidity level decreased. Alternatively, blood feeding rates and dissemination rates peaked at the intermediate humidity level, but returned to the levels of the control at the lowest humidity treatment. These results provide empirical evidence that Ae. aegypti exposure to low humidity can enhance Zika virus infection in the mosquito, which has important implications in predicting how climate change will impact mosquito-borne viruses.

Extensive variation and strain-specificity in dengue virus susceptibility among African Aedes aegypti populations

African populations of the mosquito Aedes aegypti are usually considered less susceptible to infection by human-pathogenic flaviviruses than globally invasive populations found outside Africa. Although this contrast has been well documented for Zika virus (ZIKV), it is unclear to what extent it is true for dengue virus (DENV), the most prevalent flavivirus of humans. Addressing this question is complicated by substantial genetic diversity among DENV strains, most notably in the form of four genetic types (DENV1 to DENV4), that can lead to genetically specific interactions with mosquito populations. Here, we carried out a continent-wide survey of DENV susceptibility using a panel of field-derived Ae. aegypti colonies from across the African range of the species and a colony from Guadeloupe, French West Indies as non-African reference. We found considerable variation in the ability of African Ae. aegypti populations to acquire and replicate a panel of six DENV strains spanning the four DENV types. Although African Ae. aegypti populations were generally less susceptible than the reference non-African population from Guadeloupe, in several instances some African populations were equally or more susceptible than the Guadeloupe population. Moreover, the relative level of susceptibility between African mosquito populations depended on the DENV strain, indicating genetically specific interactions. We conclude that unlike ZIKV susceptibility, there is no clear-cut dichotomy in DENV susceptibility between African and non-African Ae. aegypti. DENV susceptibility of African Ae. aegypti populations is highly heterogeneous and largely governed by the specific pairing of mosquito population and DENV strain.

Dehydration induced AePer50 regulates midgut infection in Ae. aegypti

In the face of climate change, mosquitoes will experience evolving climates including longer periods of drought. An important physiological response to dry environments is the protection against water loss or dehydration, here defined as desiccation tolerance. Various environmental factors including temperature are known to alter interactions between the mosquito, Aedes aegypti , and the arboviruses it transmits, but little is known about how low humidity impacts arboviral infection. Here, we report that a gene upregulated in response to desiccation is important for controlling midgut infection. We have identified two genetically diverse lines of Ae. aegypti with marked differences in desiccation tolerance. To understand if the genetic basis underlying desiccation tolerance is the same between the contrasting lines, we compared gene expression profiles between desiccant treated and non-desiccant treated individuals in both the desiccation tolerant and susceptible lines by RNAseq. Gene expression analysis demonstrates that different genes are differentially expressed in response to desiccation stress between desiccation tolerant and susceptible lines. The most highly expressed transcript under desiccation stress in the desiccation susceptible line encodes a peritrophin protein, Ae Per50. Peritrophins play a crucial role in peritrophic matrix formation after a bloodmeal. Gene silencing of Ae Per50 by RNAi demonstrates that expression of Ae Per50 is required for survival of the desiccation susceptible line under desiccation stress, but not for the desiccation tolerant line. Moreover, the knockdown of Ae Per50 results in higher infection rates and viral replication rates of ZIKV and higher infection rates of CHIKV. Finally, following a bloodmeal, the desiccation susceptible line develops a thicker peritrophic matrix than the desiccation tolerant line. Together these results provide a functional link between the protection against desiccation and midgut infection which has important implications in predicting how climate change will impact mosquito-borne viruses.

The influence of the larval microbiome on susceptibility to Zika virus is mosquito genotype-dependent

The microbiome of the mosquito Aedes aegypti is largely determined by the environment and influences mosquito susceptibility for arthropod-borne viruses (arboviruses). Larval interactions with different bacteria can have carry-over effects on adult Ae. aegypti replication of arboviruses, but little is known about the role that mosquito host genetics play in determining how larval-bacterial interactions shape Ae aegypti susceptibility to arboviruses. To address this question, we isolated single bacterial isolates and complex microbiomes from Ae. aegypti larvae from various field sites in Senegal. Either single bacterial isolates or complex microbiomes were added to two different genetic backgrounds of Ae. aegypti in a gnotobiotic larval system. Using 16S amplicon sequencing we showed that the bacterial community structure differs between the two genotypes of Ae. aegypti when given identical microbiomes, and the abundance of single bacterial taxa differed between Ae. aegypti genotypes. Using single bacterial isolates or the entire preserved complex microbiome, we tested the ability of specific larval microbiomes to drive differences in infection rates for Zika virus in different genetic backgrounds of Ae. aegypti. We observed that the proportion of Zika virus-infected adults was dependent on the interaction between the larval microbiome and Ae. aegypti host genetics. By using the larval microbiome as a component of the environment, these results demonstrate that interactions between the Ae. aegypti genotype and its environment can influence Zika virus infection. As Ae. aegypti expands and adapts to new environments under climate change, an understanding of how different genotypes interact with the same environment will be crucial for implementing arbovirus transmission control strategies.

The influence of the larval microbiome on susceptibility to Zika virus is mosquito genotype dependent

The microbiome of the mosquito Aedes aegypti is largely determined by the environment and influences mosquito susceptibility for arthropod-borne viruses (arboviruses). Larval interactions with different bacteria can influence adult Ae. aegypti replication of arboviruses, but little is known about the role that mosquito host genetics play in determining how larval-bacterial interactions shape Ae aegypti susceptibility to arboviruses. To address this question, we isolated single bacterial isolates and complex microbiomes from Ae. aegypti larvae from various field sites in Senegal. Either single bacterial isolates or complex microbiomes were added to two different genetic backgrounds of Ae. aegypti in a gnotobiotic larval system. Using 16S amplicon sequencing we show that similarities in bacterial community structures when given identical microbiomes between different genetic backgrounds of Ae. aegypti was dependent on the source microbiome, and the abundance of single bacterial taxa differed between Ae. aegypti genotypes. Using single bacterial isolates or the entire preserved complex microbiome, we tested the ability of specific microbiomes to drive differences in infection rates for Zika virus in different genetic backgrounds of Ae. aegypti . We observed that the proportion of Zika virus-infected adults was dependent on the interaction between the larval microbiome and Ae. aegypti host genetics. By using the larval microbiome as a component of the environment, these results demonstrate that interactions between the Ae. aegypti genotype and its environment can influence Zika virus infection. As Ae. aegypti expands and adapts to new environments under climate change, an understanding of how different genotypes interact with the same environment will be crucial for implementing arbovirus transmission control strategies.

Dating the origin and spread of specialization on human hosts in Aedes aegypti mosquitoes

The globally invasive mosquito subspecies Aedes aegypti aegypti is an effective vector of human arboviruses, in part because it specializes in biting humans and breeding in human habitats. Recent work suggests that specialization first arose as an adaptation to long, hot dry seasons in the West African Sahel, where Ae. aegypti relies on human-stored water for breeding. Here, we use whole-genome cross-coalescent analysis to date the emergence of human-specialist populationsand thus further probe the climate hypothesis. Importantly, we take advantage of the known migration of specialists out of Africa during the Atlantic Slave Trade to calibrate the coalescent clock and thus obtain a more precise estimate of the older evolutionary event than would otherwise be possible. We find that human-specialist mosquitoes diverged rapidly from ecological generalists approximately 5000 years ago, at the end of the African Humid Period-a time when the Sahara dried and water stored by humans became a uniquely stable, aquatic niche in the Sahel. We also use population genomic analyses to date a previously observed influx of human-specialist alleles into major West African cities. The characteristic length of tracts of human-specialist ancestry present on a generalist genetic background in Kumasi and Ouagadougou suggests the change in behavior occurred during rapid urbanization over the last 20-40 years. Taken together, we show that the timing and ecological context of two previously observed shifts towards human biting in Ae. aegypti differ; climate was likely the original driver, but urbanization has become increasingly important in recent decades.

Enhanced mosquito vectorial capacity underlies the Cape Verde Zika epidemic

The explosive emergence of Zika virus (ZIKV) across the Pacific and Americas since 2007 was associated with hundreds of thousands of human cases and severe outcomes, including congenital microcephaly caused by ZIKV infection during pregnancy. Although ZIKV was first isolated in Uganda, Africa has so far been exempt from large-scale ZIKV epidemics, despite widespread susceptibility among African human populations. A possible explanation for this pattern is natural variation among populations of the primary vector of ZIKV, the mosquito Aedes aegypti. Globally invasive populations of Ae. aegypti outside of Africa are considered effective ZIKV vectors because they are human specialists with high intrinsic ZIKV susceptibility, whereas African populations of Ae. aegypti across the species' native range are predominantly generalists with low intrinsic ZIKV susceptibility, making them less likely to spread viruses in the human population. We test this idea by studying a notable exception to the patterns observed across most of Africa: Cape Verde experienced a large ZIKV outbreak in 2015 to 2016. We find that local Ae. aegypti in Cape Verde have substantial human-specialist ancestry, show a robust behavioral preference for human hosts, and exhibit increased susceptibility to ZIKV infection, consistent with a key role for variation among mosquito populations in ZIKV epidemiology. These findings suggest that similar human-specialist populations of Ae. aegypti in the nearby Sahel region of West Africa, which may be expanding in response to rapid urbanization, could serve as effective vectors for ZIKV in the future.

Diagnosis of paediatric TB using Xpert® MTB/RIF Ultra on fresh respiratory samples

OBJECTIVE: To evaluate the diagnostic accuracy of Xpert^® MTB/RIF Ultra (Ultra) on fresh respiratory samples for the diagnosis of pulmonary TB (PTB) in children.METHODS: Between July 2017 and December 2019, children with presumed TB were prospectively enrolled at clinical sites in three African countries. Children were assessed using history, physical examination and chest X-ray. Sputum or gastric aspirate samples were analysed using Ultra and culture. The diagnostic accuracy of Ultra was calculated against culture as the reference standard.RESULTS: In total, 547children were included. The median age was 4.7 years, 77 (14.1%) were HIV infected and 77 (14.1%) had bacteriologically confirmed TB. Ultra detected an additional 20 cases in the group of children with negative culture results. The sensitivity of Ultra was 66.3% (95% CI 47-82), and the specificity was 95.4% (95% CI 89-99) when assessed against culture as the reference standard.CONCLUSION: Despite the improved performance of Ultra as compared to Xpert as was previously reported, its sensitivity remains sub-optimal for the detection of TB in children. Ultra detected additional 20 cases which otherwise could not have been detected by culture alone, suggesting that the latter is an imperfect reference standard.

[Knowledges And Practices Of Iron Prescription By The Pediatric Ward In CHU Gabriel Touré Of Bamako, Mali]

GOAL

To assess knowledges and practices on iron prescription in pediatric ward in CHU Gabriel Touré of Bamako, Mali.

TOOLS AND METHODS

It was a prospective and transversal study canied out. We submitted questionnaire and analyzed the case history of to the children aged 1-60 months old who received iron during the study period from 1rstto 30 July 2012. The prescriptators' consent were solicited and obtained at first of all.

RESULTS

Fifty prestators were interviewed among them 10 pediatricians (20%), 31 pediatrics' resident (62 %), 2 generalists physicians (4%), 7 medical student (14%). One hundred 100 were analyzed medical records. More than half of the prestators known the need of iron in children. Thirty percent have received iron at 8 to 10mg/kg. The medication duration wasn't indicating in 92% of patients. In our context prestators well know about meaning and the needs of iron in children bout they're limited on iron food sources and iron storage.

CONCLUSION

The well theorical knowledge on indications and prescription roules on iron in children didn't escape from miss practices in its prescription. Moreover works should analyze the reasons of discrepancies.

[Particularities of early neonatal bacterial infection in the hospital environment of the CHU Gabriel Touré in Bamako]

INTRODUCTION

Early neonatal bacterial infection (ENBI) is a major concern in neonatology. In Mali, no study had addressed this aspect, hence the initiation of this work to study the epidemiological-clinical, biological and bacteriological profile of ENBI.

MATERIALS AND METHODS

This was a descriptive longitudinal study that took place from june 27 to september 3, 2016 involving newborns aged ≤ 72 hours hospitalized for ENBI confirmed by blood culture in the neonatology service of the pediatrics department of the Center Hospitalier et Universitaire (CHU) Gabriel Toure in Bamako. The parameters studied were the socio-demographic and obstetrical characteristics of the mothers, the clinical, biological and bacteriological characteristics of newborns infected early.

RESULTS

Of the 324 blood cultures performed, 52 were positive, i.e. an ENBI frequency of 11.04%. The sex ratio was 1.3 with 73.1% low birth weight. On admission, 90.4% of newborns had less than 24 hours of life and 86.5% were births outside the CHU Gabriel Toure. The main clinical signs were hyperthermia or hypothermia and respiratory distress. The main bacteria isolated in blood culture were Staphylococcus aureus (55.8%), Klebsiella pneumoniae (13.5%) and Escherichia coli (07.7%). Sensitivity to first-line biantibiotic therapy (ceftriaxone + gentamicin) was low (63.6%) and that of amikacin was better (100%). Half of the newborns infected early died and 19.2% of exeat without medical agreement was recorded.

CONCLUSION

Early neonatal bacterial infection is a major cause of neonatal morbidity and mortality. In our context, amikacin could be a better therapeutic alternative.

[Portal cavernoma at child about two observations]

We report two observations of portal cavernoma diagnosed successively in Bamako and Dakar. The first is a 6-year-old male admitted to the service for ascites and abdominal pain. At admission the clinical parameters (weight, height, temperature, cranial perimeter and temperature) were within the norms for age. The clinical examination noted a moderate skin-mucosal pallor, asthenia. The biological assessment returned to moderate normochrome anemia with impaired pancreatic function while renal and hepatic functions were maintained. The abdominal scan performed after two low-contribution abdominal ultrasounds, objected signs in favor of a portal cavernoma with perisplenic and gastric varicose veins. The second is an 8-year-old male child born from an unborn marriage and from a followed pregnancy with premature delivery. His pathological history includes a notion of prematurity that required a stay in neonatology with umbilical catheterization and repeated abdominal pain. He had an acute abdominal episode in March 2015 justifying a surgical hospitalization for suspicion of appendicitis. At admission the clinical parameters (weight, height, temperature, cranial perimeter and temperature) were within the norms for age. The abdominal ultrasound prescribed for this was suggestive of portal cavernoma, later confirmed by abdominal computed tomography.

Isoniazid preventive therapy in child household contacts of adults with active TB in Bamako, Mali

BACKGROUND AND OBJECTIVE

Isoniazid preventive therapy (IPT) is known to reduce the risk of developing active TB in about 59% in children aged ⩽15 years. We assessed adherence, completion and adverse events among children who were household contacts of a newly diagnosed adult with smear-positive TB in Bamako, Mali.

METHODS

Children aged <15 years living in the same house with an adult smear-positive index case were enrolled in the study in the Bamako Region after consent was obtained from the parent or legal guardian. Adherence was assessed based on the number of tablets consumed during 6 months.

RESULTS

A total of 260 children aged <15 years were identified as household contacts of 207 adult patients with smear-positive TB during the study period. Among all child contacts, 130/260 (50.0%) were aged 0-4 years and were eligible for IPT; 128/130 (98.5%) were started on IPT and 83/128 (64.8%) completed with good adherence at the end of the 6 months, and without any significant adverse events.

CONCLUSION

We successfully implemented IPT with good acceptance, but low completion rate. The Mali National TB Program and partners should expand this strategy to reach more children in Bamako and the whole country and create greater awareness in the population.

Enhanced Zika virus susceptibility of globally invasive Aedes aegypti populations

The drivers and patterns of zoonotic virus emergence in the human population are poorly understood. The mosquito Aedes aegypti is a major arbovirus vector native to Africa that invaded most of the world's tropical belt over the past four centuries, after the evolution of a "domestic" form that specialized in biting humans and breeding in water storage containers. Here, we show that human specialization and subsequent spread of A. aegypti out of Africa were accompanied by an increase in its intrinsic ability to acquire and transmit the emerging human pathogen Zika virus. Thus, the recent evolution and global expansion of A. aegypti promoted arbovirus emergence not solely through increased vector-host contact but also as a result of enhanced vector susceptibility.

[Drug-resistant tuberculosis with rifampicin in children co-infected with HIV in Bamako]

Drug-resistant tuberculosis, especially in children, is a major public health challenge. We report a case with rifampicin resistance diagnosed in an HIV co-infected in Bamako. The history of the disease suggests possible father-to-child transmission. After confirmation, MDR-TB treatment was initiated. Global improvement and normalization of biological parameters and X-Ray was obtained. The identification of this case highlights the need to improve diagnosticand treatment algorithms for rapid confirmation and better management.

[Socio-demographic, clinical, and therapeutic aspects of adolescents treated and followed for HIV infection at the Hospital Gabriel Toure paediatric center]

HIV infection is a chronic infectious disease requiring long-term management and regular follow-up of patients.

OBJECTIVES

The aims of this study was to describe the socio-demographic, clinical, biological and therapeutic aspects of adolescents treated and followed for HIV infection at the Hospital Gabriel Toure paediatric center.

PATIENTS AND METHODS

From 01/01/2001 to 31/12/2017, the medical records of children followed for HIV infection until adolescence were analyzed. It was a descriptive and analytical retrospective study.

RESULTS

One thousand five hundred and fourteen patients received antiretroviral treatment and 587 were still in follow-up on 31 December 2017, including 393 adolescents (sex-ratio = 1.2). The median age was 14.25 years and 55.1% of children had lost at least one parent. HIV serology was positive among mothers in 61.7% of cases (n=342), and 63% of them were on ARVs. Sixty-eight per cent of children were WHO Stage III or IV at the time of ART initiation. The median age at onset of ART was 53 months (26-96 months). The combination of 2 nucleotide reverse transcriptase inhibitors (NRTIs) with a non-nucleotide reverse transcriptase inhibitor (NNRTI) was used in 89% of patients. The median CD4 count before ARV treatment was 438/mm3. The average duration of follow-up under treatment was 9.8 ± 3.4 years. Fifty-one percent of adolescents had undetectable viral load. There was a correlation between the initiation of a second line of treatment and treatment failure (p<0.001).

CONCLUSION

The adherence of adolescents to ARV treatment requires the implementation of innovative strategies to improve the therapeutic success rate.

[Epidemiology and prognosis of eclampsia in Bougouni]

OBJECTIVES

The objectives were to describe the epidemiological and prognostic aspects of eclampsia in the Bougouni reference health center.

METHODS

This was a transversal prospective, descriptive study from January 1 to December 31, 2015 in the gynecology-obstetrics department of Bougouni reference health center. Were included, all pregnant or postpartum women diagnosed with eclampsia during the study period.

RESULTS

The frequency of eclampsia was 2.54%. They were adolescent girls in 50% of cases, primigest in 62.5% of cases, unschooled in 67.5% of cases, having not performed any antenatal care in 70% of cases. Eclampsia occurred in antepartum in 37.5% of cases, in 5% in perpartum and in 57.5% in postpartum. Therapeutically, nicardipine with 72.5% and nifedipine with 22.5% were the antihypertensive drugs used. As for anticonvulsants, magnesium sulfate (MgSO4) was used in 92.5% and diazepam in 7.5%. The maternal-fetal prognosis was marked by 2.5% of maternal death, 27% of prematurity and 27.5% of fetal death in utero.

CONCLUSION

Eclampsia is a dreadful pathology with serious maternal and fetal complications.

Climate and Urbanization Drive Mosquito Preference for Humans

The majority of mosquito-borne illness is spread by a few mosquito species that have evolved to specialize in biting humans, yet the precise causes of this behavioral shift are poorly understood. We address this gap in the arboviral vector Aedes aegypti. We first collect and characterize the behavior of mosquitoes from 27 sites scattered across the species' ancestral range in sub-Saharan Africa, revealing previously unrecognized variation in preference for human versus animal odor. We then use modeling to show that over 80% of this variation can be predicted by two ecological factors-dry season intensity and human population density. Finally, we integrate this information with whole-genome sequence data from 375 individual mosquitoes to identify a single underlying ancestry component linked to human preference. Genetic changes associated with human specialist ancestry were concentrated in a few chromosomal regions. Our findings suggest that human-biting in this important disease vector originally evolved as a by-product of breeding in human-stored water in areas where doing so provided the only means to survive the long, hot dry season. Our model also predicts that the rapid urbanization currently taking place in Africa will drive further mosquito evolution, causing a shift toward human-biting in many large cities by 2050.

[Materno-Fetal Prognosis Of Anemia In Bougouni]

GOAL

The goal was to assess the maternal-fetal prognosis of anemia in pregnant women in the Bougouni reference health center.

METHODS

We carried out a prospective descriptive and analytical cross-sectional study from January 1 to December 31, 2013 at the Bougouni reference health center. It covered all pregnant women with a hemoglobin level below 11g/dl regardless of the outcome of the pregnancy.

RESULTS

The prevalence of anemia in pregnant women was 33.2%. They were women married to peasants in 88.6% of cases, unschooled in 93.2% of cases, having not done antenal care in 56.8% of cases. Malaria was the most common etiology in 75% of cases. Anemia was severe in 61.4% of cases. The maternal-fetal prognosis was dominated by 3.3% of maternal death, 12.5% of abortion, 7.6% of prematurity and 6.8% of fetal death in utero.

CONCLUSION

Anemia in pregnant women is the source of many maternal-fetal complications.

[Management of Acute Malnutrition in Children in a Sahelian Secondary Hospital]

Malnutrition among children under five is a major public health problem in low-income countries, and contributes significantly to mortality in this age group. The purpose of this work was to evaluate the epidemiological and clinical profile of malnourished children at the Nara hospital in north of Mali.

METHOD

It was a retrospective and descriptive study, from 01/01/2016 to 31/12/2016. Children aged 6 months to 59 months admitted for acute malnutrition were included.

RESULTS

Four hundred and sixty-one children had malnutrition, representing 15% of consultations and 50% of hospitalizations. The median age was 26 months (2 months-93 months). The sex ratio was 0.92 (M = 222, F = 239). Nineteen percent of the patients had progressive weaning (n = 90), and it was brutal in 371 patients (80%). The distribution of patients according to the Z-score was as follows: Z-score <-1 (n = 15, 3%), Z-score <-2 (n = 46, 10%), Z-score <-3 (n = 400, 87%). Mean MUAC was 105 mm (99mm-124mm). Hypoglycemia was noted in 45% (n = 204). The marasmus cases accounted for 80% (n = 367) kwashiorkor 10% (n = 48). The mixed form of malnutrition accounted for 10% (n = 46). The disease associated with malnutrition were pneumonia (n = 219, 47%), malaria (n = 115, 25%) and gastroenteritis (n = 68, 15%). The F75 milk was administered predominantly for 3 months in 93% of cases. For phase 2 of treatment, Plumpy Nut and F100 milk were respectively administered in 88% and 12%. The nutritional recovery rate was 95% (n = 435). Five percent of the patients died (n = 26). Pneumonia was the cause of death in 85% of cases. The cure rate for marasmus and kwashiorkor cases was respectively 94% and 93%.

CONCLUSION

Acute malnutrition remains frequent in the Sahelian environment. Better knowledge of mothers about weaning and dietary diversification will improve the nutritional status of children.

Childhood brain tumors in Mali

to assess epidemiologic and clinical aspects of childhood brain tumors in Mali. a retrospective, descriptive study of children aged 0-15 years with brain tumors, conducted in the pediatrics department of the Gabriel Touré University Hospital Center in Bamako, Mali, from January 31, 2007 to December 3, 2012. In all, 41 cases of brain tumors were recorded during this period (mean: 5.5 years old; range: 1-12 years). Brain tumors were most frequent in the children aged 2-5 years (53.7%) and among boys (53.7%). Late stage at presentation was relatively frequent (34.1%) with a mean time to diagnosis of 10 months. Features of elevated intracranial pressure were the most frequent mode of revelation of primary tumors (26.8%). Supratentorial tumors accounted for 83% of the cases, and gliomas were most frequently (29.3%) identified on computed tomography. Only five patients underwent surgical tumor removal. A broader study including the other hospitals in Bamako could help to assess more accurately the epidemiology of pediatric brain tumors in Mali.

[Accidental household poisoning of the child at the Gabriel Toure university hospital center in Bamako]

INTRODUCTION

Household accidental child poisonings are frequent pediatric medical emergencies in developing countries.

OBJECTIVE

To study the epidemiological, etiological, clinical and therapeutic aspects of acute accidental domestic poisoning in children aged 0 to 15 years admitted to the pediatric emergency department of Gabriel Toure.

METHOD

This was a prospective, descriptive study that ran from January 1, 2014 to December 31, 2014. All patients aged 0 to 15 years admitted to pediatric emergencies for acute intoxication were included.

RESULTS

A hundred cases of acute accidental poisoning were collected. Children under five accounted for 94%. The majority of mothers was housewives and had custody of children (83%). Forty-nine percent of the mothers were unschooled. The place of storage of the product was indoor in 96% of cases. The product was taken by the child himself (88%). A gesture at the scene of the accident was reported in 68% of cases, the ingestion of milk (72%) and water (10%) were the first acts used. The hospital was the first resort (72%). The time between taking the product and admission to hospital was 1 to 5 hours in 58% of cases. Vomiting (37 cases), agitation (17 cases) and respiratory distress (16 cases) were the most common symptoms. Domestic products (48%) followed by drugs (33%) ranked first among the families of poisons. Caustic soda (18%) and bleach (17%) were the most commonly found intoxication products. The evolution was good with a cure without sequelae (93%).

CONCLUSION

Accidental acute intoxications to household products are common in Mali. The hospital admission deadline is still long; the actions taken by patients at the accident site often aggravate their states but are largely done by the parents before the use of health care.

Species Identification and Resistance Status of Anopheles gambiae s.l. (Diptera: Culicidae) Mosquitoes in Guinea

Insecticide resistance is one of the primary threats to the recent gains in malaria control. This is especially true in Guinea, where long-lasting insecticidal nets are currently the primary vector control intervention. To better inform the national malaria control program on the current status of insecticide resistance in Guinea, resistance bioassays were conducted, using Anopheles gambiae s.l. Giles, in three sites. Molecular analyses were also done on An. gambiae s.l. to determine the species and find whether the target-site mutations kdr and Ace1R were present. Susceptibility tests revealed resistance to DDT and pyrethroids, although mosquitoes were susceptible to deltamethrin in two of the three sites tested. Mosquitoes were susceptible to bendiocarb, except in Kissidougou, Guinea. The kdr-west mutation was widespread and the frequency was 60% or more in all sites. However, the Ace1R mutation was present in low levels. Insecticide susceptibility should continue to be monitored in Guinea to ensure insecticide-based vector control methods remain effective.

Population genomics reveals that an anthropophilic population of Aedes aegypti mosquitoes in West Africa recently gave rise to American and Asian populations of this major disease vector

BACKGROUND

The mosquito Aedes aegypti is the main vector of dengue, Zika, chikungunya and yellow fever viruses. This major disease vector is thought to have arisen when the African subspecies Ae. aegypti formosus evolved from being zoophilic and living in forest habitats into a form that specialises on humans and resides near human population centres. The resulting domestic subspecies, Ae. aegypti aegypti, is found throughout the tropics and largely blood-feeds on humans.

RESULTS

To understand this transition, we have sequenced the exomes of mosquitoes collected from five populations from around the world. We found that Ae. aegypti specimens from an urban population in Senegal in West Africa were more closely related to populations in Mexico and Sri Lanka than they were to a nearby forest population. We estimate that the populations in Senegal and Mexico split just a few hundred years ago, and we found no evidence of Ae. aegypti aegypti mosquitoes migrating back to Africa from elsewhere in the tropics. The out-of-Africa migration was accompanied by a dramatic reduction in effective population size, resulting in a loss of genetic diversity and rare genetic variants.

CONCLUSIONS

We conclude that a domestic population of Ae. aegypti in Senegal and domestic populations on other continents are more closely related to each other than to other African populations. This suggests that an ancestral population of Ae. aegypti evolved to become a human specialist in Africa, giving rise to the subspecies Ae. aegypti aegypti. The descendants of this population are still found in West Africa today, and the rest of the world was colonised when mosquitoes from this population migrated out of Africa. This is the first report of an African population of Ae. aegypti aegypti mosquitoes that is closely related to Asian and American populations. As the two subspecies differ in their ability to vector disease, their existence side by side in West Africa may have important implications for disease transmission.

[Congenital Hypothyroidism: 2 observed cases at the Gabriel Toure University Hospital of Bamako, Mali]

We report two observations of congenital hypothyroidism diagnosed in 2011 in the university hospital of Gabriel Toure in Bamako. The first occurred in a male infant of 40 days, admitted for respiratory distress and anterior compressive cervical swelling. Although his neonatal period occurred without any medical particularity, family medical history revealed the presence of unexplored goiter in three paternal uncles. Neurological examination was normal with the presence of constipation. A cervical-thoracic scan showed a homogeneous and symmetric hypertrophy of thyroid lobes with a compression of the trachea. The dosage of thyroid hormones confirmed hypothyroidism (FT4 = 1.6 pmol/l, TSH = 60 µUI/ml). After one month of treatment using Levothyroxine, 10 mg/kg, there was a drastic improvement of respiratory distress, a regression of goiter and normalization of thyroid hormones. At six months of life he had no goiter and psychomotor development was normal. The second case occurred in a male infant of 2 years, from an area of endemic goiter. Puffiness of the face without lower limb edema, constipation, and delayed independent walking were the reasons for consultation. On examination, we noted the absence of goiter, large anterior fontanel with facial dysmorphism (lunar facies, hypertelorism, flat nose, macroglossia) and infiltration of the skin more marked in the face with cold extremities. He required support to sit. The thyroid function tests confirmed hypothyroidism (FT4 = 72 nmol/l, FT3 = 0.40 nmol/l, TSH > 60 µUI/l). Under levothyroxine, there was normalization of thyroid hormones after one month of treatment and disappearance of the skin infiltration. At six months of treatment he had acquired independent walking. Mental prognosis remains to be evaluated. These cases confirm the necessity of routine neonatal diagnosis of hypothyroidism.

Reproductive Incompatibility Involving Senegalese Aedes aegypti (L) Is Associated with Chromosome Rearrangements

Aedes aegypti, the primary vector of dengue, yellow fever and Zika flaviviruses, consists of at least two subspecies. Aedes aegypti (Aaa) is light in color, has pale scales on the first abdominal tergite, oviposits in artificial containers, and preferentially feeds on humans. Aedes aegypti formosus (Aaf), has a dark cuticle, is restricted to sub-Saharan Africa, has no pale scales on the first abdominal tergite and frequently oviposits in natural containers. Scale patterns correlate with cuticle color in East Africa but not in Senegal, West Africa where black cuticle mosquitoes display a continuum of scaling patterns and breed domestically indoors. An earlier laboratory study did not indicate any pre- or postzygotic barriers to gene flow between Aaa and Aaf in East Africa. However, similar attempts to construct F₁ intercross families between Aaa laboratory strains and Senegal Ae. aegypti (SenAae) failed due to poor F₁ oviposition and low F₂ egg-to-adult survival. Insemination and assortative mating experiments failed to identify prezygotic mating barriers. Backcrosses were performed to test for postzygotic isolation patterns consistent with Haldane’s rule modified for species, like Aedes, that have an autosomal sex determining locus (SDL). Egg-pupal survival was predicted to be low in females mated to hybrid F₁ males but average when a male mates with a hybrid F₁ female. Survival was in fact significantly reduced when females mated to hybrid males but egg-pupal survival was significantly increased when males were mated to hybrid F₁ females. These observations are therefore inconclusive with regards to Haldane’s rule. Basic cytogenetic analyses and Fluorescent In Situ Hybridization (FISH) experiments were performed to compare SenAae strains with the IB12 strain of Aaa that was used for genome sequencing and physical mapping. Some SenAae strains had longer chromosomes than IB12 and significantly different centromeric indices on chromosomes 1 and 3. DAPI staining was used to identify AT-rich regions, chromomycin A3 following pretreatment with barium hydroxide stained for GC-rich regions and stained the ribosomal RNA locus and YOYO-1 was used to test for differential staining. Chromosome patterns in SenAae strains revealed by these three stains differed from those in IB12. For FISH, 40 BAC clones previously physically mapped on Aaa chromosomes were used to test for chromosome rearrangements in SenAae relative to IB12. Differences in the order of markers identified two chromosomal rearrangements between IB12 and SenAae strains. The first rearrangement involves two overlapping pericentric (containing the centromere) inversions in chromosome 3 or an insertion of a large fragment into the 3q arm. The second rearrangement is close to the centromere on the p arm of chromosome 2. Linkage analysis of the SDL and the white-eye locus identified a likely chromosomal rearrangement on chromosome 1. The reproductive incompatibility observed within SenAae and between SenAae and Aaa may be generally associated with chromosome rearrangements on all three chromosomes and specifically caused by pericentric inversions on chromosomes 2 and 3.

Aedes aegypti is one of the best studied mosquito species and it is the principal vector of dengue, Zika, and yellow fever flaviviruses and the Chikungunya alphavirus. Aedes aegypti occurs throughout all tropical and subtropical regions of the world, and previous population genetic studies have shown that the highest genetic diversity occurs in Africa. Aedes aegypti from Senegal, West Africa (SenAae) have a low oviposition rate; those that do oviposit have a low fecundity and poor egg-to-adult survival. Furthermore rearrangements were detected on all three chromosomes in SenAae. These observations are consistent with the presence of at least two cryptic subspecies of Ae. aegypti in Senegal arising from reproductive isolation due to chromosome rearrangements. Genetic control strategies are being considered for the suppression of Ae. aegypti populations worldwide. Barriers to gene flow in African Ae. aegypti populations could compromise these future control efforts.

Ethnomedical and ethnobotanical investigations on the response capacities of Guinean traditional health practioners in the management of outbreaks of infectious diseases: The case of the Ebola virus epidemic

ETHNOPHARMACOLOGICAL RELEVANCE

The recent outbreak of Ebola virus infections has mostly remained confined to the West African countries Guinea-Conakry, Sierra-Leone and Liberia. Due to intense national and international mobilizations, a significant reduction in Ebola virus transmission has been recorded. While international efforts focus on new vaccines, medicines and diagnostics, no coherent national or international approach exists to integrate the potential of the traditional health practitioners (THPs) in the management of infectious diseases epidemics. Nevertheless, the first contact of most of the Ebola infected patients is with the THPs since the symptoms are similar to those of common traditionally treated diseases or symptoms such as malaria, hemorrhagic syndrome, typhoid or other gastrointestinal diseases, fever and vomiting.

MATERIALS AND METHODS

In an ethnomedical survey conducted in the 4 main Guinean regions contacts were established with a total of 113 THPs. The socio-demographic characteristics, the professional status and the traditional perception of Ebola Virus Disease (EVD) were recorded.

RESULTS

The traditional treatment of the main symptoms was based on 47 vegetal recipes which were focused on the treatment of diarrhea (22 recipes), fever (22 recipes), vomiting (2 recipes), external antiseptic (2 recipes), hemorrhagic syndrome (2 recipes), convulsion and dysentery (one recipe each). An ethnobotanical survey led to the collection of 54 plant species from which 44 identified belonging to 26 families. The most represented families were Euphorbiaceae, Caesalpiniaceae and Rubiaceae. Literature data on the twelve most cited plant species tends to corroborate their traditional use and to highlight their pharmacological potential.

CONCLUSIONS

It is worth to document all available knowledge on the traditional management of EVD-like symptoms in order to evaluate systematically the anti-Ebola potential of Guinean plant species.

[Knowledge and practices regarding iron prescription by medical staff of the pediatric ward in the Gabriel Touré university hospital of Bamako, Mali]

GOAL

To assess knowledge and practices on iron prescription in the pediatric ward of the Gabriel Touré university hospital of Bamako, Mali.

MATERIAL AND METHODS

A cross-sectional study was carried out from the 1st to 31st July 2012 in the service. We presented the participants with a questionnaire and analyzed the medical files of children aged 1-60 months old who received an iron prescription. Each prescriber's consent was solicited and obtained prior to the study.

RESULTS

Fifty prescribers were interviewed, among them 10 pediatricians (20%), 31 pediatrics' residents (62%), 2 generalist physicians (4%), 7 medical student (14%); and 100 medical records were analyzed. More than half of the prescribers were aware of the need of iron in children, with 42% knowing about iron reserves. 8% of prescribers knew that iron absorbed through food was heme iron or non-heme iron. Thirty percent of patients received iron at a dose of 8 to 10mg/kg. Length of treatment was not indicated in 92% of patients.

CONCLUSION

In our context, sufficient theoretical knowledge and of children's iron need did not exclude bad prescription practices. Future studies should analyze the reasons of behind this discrepancy.

[Neuromalarian lesions in the pediatric unit, Gabriel Toure University Hospital (Bamako, Mali)]

INTRODUCTION

Malaria is one of the rare public health plagues which has been prevailing over centuries. It is severe around the world poverty line and remains the most widely spread disease in intertropical zones. The Afro-tropical region, which accounts for 8% of the world population, bears the heaviest malaria burden, with 80% to 90% of cases (200 to 280 millions) among which, 90% are due to P. falciparum.

OBJECTIVE

To study neuromalarian lesions in 0-15 year old children in the Pediatric Unit at Gabriel Touré, University Hospital.

MATERIALS AND METHODS

From February 2009 to January 2010 the study covered 92 children, aged 0-15 years old, with neuromalarian lesions hospitalized at the Pediatric unit of the Gabriel Toure University Hospital.

RESULTS

2230 patients were received suffering from malaria, among whom 1320 hospitalized for neuromalarian. 92 cases (6.97%) of neuromalarian lesion were identified. There were 57 boys and 35 girls, with 1.63 sex ratio. 0 to 5 years old age group was the most significant, accounting for 67.39% of subjects. Axial hypotony was the most frequent lesion encountered (65.22%). Temporary blindness was reported in six patients (6.52%). Behavior disorders were reported in seven patients (7.61%). Five patients (5.43%) were victim of hemiplegia. Axial hypotonicity was associated with aphasia in thirty-seven patients (40.22%) and peripheral hypertonia in eighteen patients (19.57%). Seven patients (7.61%) became epileptic and six (6.52%) were suffering from dystonia. Recovery effects were 50% in the short term and 73.9% in the medium term.

CONCLUSION

Despite progress made in terms of diagnosis and care, malaria still remain a fearsome pathology and source of neuromalarian lesions among which some lead to permanent disability. Early intervention and proper treatment could reduce the incidence of neuromalarian lesions.

Vector competence in West African Aedes aegypti Is Flavivirus species and genotype dependent

Background

Vector competence of Aedes aegypti mosquitoes is a quantitative genetic trait that varies among geographic locations and among different flavivirus species and genotypes within species. The subspecies Ae. aegypti formosus, found mostly in sub-Saharan Africa, is considered to be refractory to both dengue (DENV) and yellow fever viruses (YFV) compared to the more globally distributed Ae. aegypti aegypti. Within Senegal, vector competence varies with collection site and DENV-2 viral isolate, but knowledge about the interaction of West African Ae. aegypti with different flaviviruses is lacking. The current study utilizes low passage isolates of dengue-2 (DENV-2-75505 sylvatic genotype) and yellow fever (YFV BA-55 -West African Genotype I, or YFV DAK 1279-West African Genotype II) from West Africa and field derived Ae. aegypti collected throughout Senegal to determine whether vector competence is flavivirus or virus genotype dependent.

Methodology/Principal Findings

Eight collections of 20–30 mosquitoes from different sites were fed a bloodmeal containing either DENV-2 or either isolate of YFV. Midgut and disseminated infection phenotypes were determined 14 days post infection. Collections varied significantly in the rate and intensity of midgut and disseminated infection among the three viruses.

Conclusions/Significance

Overall, vector competence was dependent upon both viral and vector strains. Importantly, contrary to previous studies, sylvatic collections of Ae. aegypti showed high levels of disseminated infection for local isolates of both DENV-2 and YFV.

Vector competence is defined as the intrinsic permissiveness of an arthropod vector for infection, dissemination, and transmission of a pathogen. The mosquito Aedes aegypti is the main vector for dengue and yellow fever viruses worldwide and is divided into two subspecies: Ae. aegypti aegypti and Ae. aegypti formosus. Aedes aegypti aegypti is found globally in tropical and subtropical regions, while Ae. aegypti formosus is mainly restricted to sub-Saharan Africa. Aedes aegypti formosus is considered to be a poor vector for both yellow fever and dengue, but some of these original studies with yellow fever were performed with highly passaged viral isolates collected at different locations than the mosquitoes. Viral genetics is an important determinant of vector competence and virus/mosquito genetic specificity exists in Ae. aegypti aegypti. We compared the vector competence of multiple collections of Ae. aegypti from throughout Senegal for both yellow fever and dengue viruses to demonstrate that vector competence in Ae. aegypti formosus is dependent on viral genotype. In contrast to earlier claims, populations of Ae. aegypti in West Africa can be competent vectors of flaviviruses.

High level of HIV-1 resistance in patients failing long-term first-line antiretroviral therapy in Mali

OBJECTIVES

In resource-limited settings, few data are available on virological failure after long-term first-line antiretroviral therapy. This study characterized the genotypic resistance patterns at the time of failure after at least 36 months of a first-line regimen in Mali, West Africa.

METHODS

Plasma samples from 84 patients who were receiving first-line antiretroviral treatment and with an HIV-1 RNA viral load (VL) >1000 copies/mL were analysed. Genotypic resistance testing was performed and HIV-1 drug resistance was interpreted according to the latest version of the National Agency for HIV and Hepatitis Research algorithm.

RESULTS

At the time of resistance testing, patients had been treated for a median of 60 months (IQR 36-132 months) and had a median CD4 cell count of 292 cells/mm(3) (IQR 6-1319 cells/mm(3)), a median HIV-1 RNA level of 28266 copies/mL (IQR 1000-2 93 495 copies/mL) and a median genotypic susceptibility score of 1 (IQR 1-4). The prevalence of nucleoside reverse transcriptase inhibitor (NRTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance mutations was 78% and 82%, respectively. Viruses were resistant to at least one drug in 92% of cases. Although etravirine and rilpivirine were not used in the first-line regimens, viruses were resistant to etravirine in 34% of cases and to rilpivirine in 49% of cases. The treatment duration, median number of NRTI and NNRTI mutations and some reverse transcriptase mutations (T215Y/F/N, L210W, L74I, M41L and H221Y) were associated with the VL at virological failure.

CONCLUSIONS

This study demonstrated a high level of resistance to NRTIs and NNRTIs, compromising second-generation NNRTIs, for patients who stayed on long-term first-line regimens. It is crucial to expand the accessibility of virological testing in resource-limited settings to limit the expansion of resistance and preserve second-line treatment efficacy.

[Mothers knowledges, attitudes and practices on female genital excision in Bamako]

AIM

In Mali society, female excision is a cultural practice. Despite the awareness campaigns, it affects nearly 85% of the female population (EDSM IV). This study was initiated to assess the knowledges, attitudes and practices of mothers about female circumcision.

METHOD

We conducted a prospective, cross-sectional study from June 1 to July 31, 2011, in the Department of Pediatrics of the teaching hospital of Gabriel Touré, Bamako, regarding the knowledge, attitudes and practices of mothers related to the female excision.

RÉSULTS

We interviewed 224 mothers. The prevalence of female circumcision was 73%. In 72.7% of cases, the area affected by the mutilation was unknown to the mother. Nearly seventy percent (69.6%) of mothers thought that female circumcision had advantages only and should even be mandatory (74.6%). Female circumcision was associated with tradition, and it would be a religious obligation for 65%, and 21.4% of mothers, respectively. More than half of the girls were circumcised before their first year (76.3%) and 26.3% in the neonatal period. The majority of mothers were against a law banning the practice of female circumcision (54%). Ninety five percent of mothers reported that they would renew the experience of female circumcision.

CONCLUSION

Female circumcision remains a well-established practice. Policies to fight against female circumcision are faced to very deep beliefs.

[Isolated mandibular fractures study's in the CHU-OS of Bamako: 55 cases]

AIMS

The aim of this study was to determine sociodemographics, clinical and therapeutic aspects in patients with isolated mandibular fractures in the Bamako dentistry teaching hospital (CHU-OS).

MATERIALS AND METHODS

We carried out restrospective study over a period of four months involving isolated mandibular fracture cases, confirmed by a clinical and radiological examination in 2006. The data were collected from medical records, entered and analyzed using Epiinfo.fr 6.0 software.

RESULTS

The lesions involved 42 men and 13 women with a sex ratio of 3.23. The age group of 21-30 was the most affected. The main cause was found to be road traffic accidents with 72.72 % of the total cases. The fractures of the mandible at the level of horizontal branch were the most frequent with 34.54 %. The orthopedic treatment was used in 72.72 % of the cases, with a good and very good results.

CONCLUSION

This study shows the high frequency of isolated fractures of the mandible mainly from road traffic accidents, as well as their occurrence among young adults.

Design and testing of a novel, protective human-baited tent trap for the collection of anthropophilic disease vectors

Currently, there exists a deficit of safe, active trapping methods for the collection of host-seeking Anopheles and other disease-causing arthropod vectors. The gold-standard approach for mosquito collection is that of human landing catch (HLC), in which an individual exposes bare skin to possibly infected vectors. Here, we present the development of a new method for mosquito collection, the Infoscitex tent, which uses modern tent materials coupled with a novel trap design. This provides an efficacious, a non-labor-intensive, and a safe method for vector collection. In these initial studies, we found it collected an average of 27.7 Anopheles gambiae s.l. per trap per night in rural villages in southeastern Senegal, and 43.8 Culex group Vper trap per night in the semiurban town of Kedougou, Senegal. In direct comparisons with HLC, the tent was not statistically different for collection of Culex quinquefasciatus in crepuscular sampling, but was significantly less efficacious at trapping the highly motile dusk-biter Aedes aegypti. These studies suggest that the Infoscitex tent is a viable and safe alternative to HLC for Anopheles and Culex sampling in areas of high vector-borne disease infection risk.

Aedes species in treeholes and fruit husks between dry and wet seasons in southeastern Senegal

During the dry season in February, 2010 and the wet season in September, 2011 we sampled mosquito larvae and eggs from treeholes of seven native hardwood species and the husks of Saba senegalensis in 18 sites in the PK-10 forest in southeastern Senegal. Larvae were reared to adults for species identification. In the dry season, we recovered 408 Aedes mosquitoes belonging to seven species. Aedes aegypti s.l. comprised 42.4% of the collection, followed by Ae. unilineatus (39%). In contrast to reports from East Africa, both Ae. aegypti aegypti and Ae. aegypti formosus were recovered, suggesting that both subspecies survive the dry season in natural larval habitats in West Africa. In the wet season, 455 mosquitoes were collected but 310 (68.1%) were the facultatively predaceous mosquito Eretmapodites chrysogaster. The remaining 145 mosquitoes consisted of ten Aedes species. Aedes aegypti s.l. comprised 55.1% of these, followed by Ae. apicoargenteus (15.2%) and Ae. cozi (11.7%). Similar to East Africa, most (90%) of Ae. aegypti s.l. in the wet season were subspecies formosus.

[Malian first observation of disseminated African histoplasmosis with predominant bone localizations in an HIV-negative child in Bamako (Mali). Review of the literature]

Endemic deep fungal infections are still under recognised diseases in daily medical practice because of their rarity in sub-Saharan area. The African histoplasmosis Histoplasma capsulatum var. duboisii (H. capsulatum duboisii) is the most frequent variety described in Mali through limited studies in adult patients, since the first case described by Catanei and Kervran (1945). Our case report is a disseminated histoplasmosis in a young 6-year-old african child. He was male and rural. The infectious localisations were mucosae, skin, lymphnodes, urinary tract and bones. Evolution has been marred by an episode of worsening of symptoms despite initial clinical improvement with ketoconazole. After healing of mucocutaneous lesions, we noticed a limitation of ampliation of both wrists. The radiographic bone lesions were lysis of the right lower end of the right radius and cubitus and fragmentation of cubital epiphysis of the same arm. Lacunes were present on the fifth right finger in metatarsus and phalanx; lacune and blowing aspect of the second phalanx of the left third finger was noted. The disseminated form of African histoplasmosis may occur in HIV-negative subject. The prognosis depends on early diagnosis and administration of appropriate and well-conducted therapy.

Dual African origins of global Aedes aegypti s.l. populations revealed by mitochondrial DNA

BACKGROUND

Aedes aegypti is the primary global vector to humans of yellow fever and dengue flaviviruses. Over the past 50 years, many population genetic studies have documented large genetic differences among global populations of this species. These studies initially used morphological polymorphisms, followed later by allozymes, and most recently various molecular genetic markers including microsatellites and mitochondrial markers. In particular, since 2000, fourteen publications and four unpublished datasets have used sequence data from the NADH dehydrogenase subunit 4 mitochondrial gene to compare Ae. aegypti collections and collectively 95 unique mtDNA haplotypes have been found. Phylogenetic analyses in these many studies consistently resolved two clades but no comprehensive study of mtDNA haplotypes have been made in Africa, the continent in which the species originated.

METHODS AND FINDINGS

ND4 haplotypes were sequenced in 426 Ae. aegypti s.l. from Senegal, West Africa and Kenya, East Africa. In Senegal 15 and in Kenya 7 new haplotypes were discovered. When added to the 95 published haplotypes and including 6 African Aedes species as outgroups, phylogenetic analyses showed that all but one Senegal haplotype occurred in a basal clade while most East African haplotypes occurred in a second clade arising from the basal clade. Globally distributed haplotypes occurred in both clades demonstrating that populations outside Africa consist of mixtures of mosquitoes from both clades.

CONCLUSIONS

Populations of Ae. aegypti outside Africa consist of mosquitoes arising from one of two ancestral clades. One clade is basal and primarily associated with West Africa while the second arises from the first and contains primarily mosquitoes from East Africa.

[Reasons for hospitalisation of hiv-infected children in pediatric service of the Gabriel Toure teaching hospital, Bamako]

PURPOSE

The aim of our study was to determine the reasons of hospitalization of HIV-infected children in our context and to identify factors associated with mortality in the course of hospitalization.

PATIENTS AND METHOD

Our study took place in the department of pediatrics of the Gabriel Touré Teaching Hospital. It involved all the children hospitalized between March 1st and August 31st, 2010 to whom an infection with HIV was diagnosed before or during the hospitalization.

RESULTS

Thirty seven HIV-infected children were hospitalized. The average age at admission was 46,9 months and the sex ratio was 0,76. HIV infection was discovered during the hospitalization for 29 children (78,4%). Fifteen children were orphan of at least a parent. The medical pathological history include sickle cell disease (2 cases) and tuberculosis (1 case). The great majority (91,9%) were at WHO stage 3 or 4. The main AIDS-defining events were severe malnutrition (73%) and pneumonia (45,9%). They were followed by bacterial infections (21,6%) and malaria (13,5%). An anemia was found at 85,7 % of the children.

CONCLUSION

Efforts must be made for early diagnosis and management of pediatric's HIV infection.

Mermithid nematodes found in adult Anopheles from southeastern Senegal

Background

Over two dozen mermithid nematodes have been described parasitizing mosquitoes worldwide, however, only two species were found in Africa. Mermithid nematodes kill their mosquito host upon emergence, which suggests that they could be developed as biological control agents of mosquitoes. Both Romanomermis culicivorax and Romanomermis iyengari have been reared for mass release to control numerous Anopheles species vector populations, and in one instance this may have led to reduced malaria prevalence in a human population.

Methods

Anopheles mosquitoes were collected during a malaria study in southeastern Senegal. Two different adult blood fed mosquitoes had a single mermithid nematode emerge from their anus while they were being held post-capture. Primers from the 18 S rDNA were developed to sequence nematode DNA and screen mosquitoes for mermithid DNA. 18 S rDNA from the Senegalese mermithid and other mermithid entries in GenBank were used to create a Maximum Parsimony tree of the Mermithidae family.

Results

The mermithid was present in 1.8% (10/551) of the sampled adult Anopheles species in our study area. The mermithid was found in An. gambiae s.s., An. funestus, and An. rufipes from the villages of Ndebou, Boundoucondi, and Damboucoye. Maximum parsimony analysis confirmed that the nematode parasites found in Anopheles were indeed mermithid parasites, and of the mermithid sequences available in GenBank, they are most closely related to Strelkovimermis spiculatus.

Conclusions

To our knowledge, this is the first report of mermithids from adult Anopheles mosquitoes in Senegal. The mermithid appears to infect Anopheles mosquitoes that develop in diverse larval habitats. Although maximum parsimony analysis determined the mermithid was closely related to Strelkovimermis spiculatus, several characteristics of the mermithid were more similar to the Empidomermis genus. Future mermithid isolations will hopefully allow: formal taxonomic identification, laboratory colonization, determination of life history traits and species specificity, and characterize its usefulness as a biological control agent.

Comparative evaluation of systemic drugs for their effects against Anopheles gambiae

Laboratory and field studies have shown that ivermectin, a drug that targets invertebrate ligand-gated ion channels (LGICs), is potently active against Anopheles spp. mosquitoes at concentrations present in human blood after standard drug administrations; thus ivermectin holds promise as a mass human-administered endectocide that could help suppress malaria parasite transmission. We evaluated other systemic LGIC-targeting drugs for their activities against the African malaria vector Anopheles gambiae using in vitro blood feeding assays. Eprinomectin, selamectin, moxidectin, and N-tert-butyl nodulisporamide were evaluated as potentially systemic drugs having similar modes of action to ivermectin; all primarily are agonists of invertebrate glutamate-gated chloride ion channels. Additionally, nitenpyram and spinosad were evaluated as systemic drugs that primarily work as agonists of nicotinic acetylcholine receptor channels. Only eprinomectin killed An. gambiae at concentrations that were comparable to ivermectin. At sub-lethal doses, nitenpyram and moxidectin marginally affected mosquito re-blood feeding ability. The macrocyclic lactones, particularly eprinomectin, caused significantly increased knockdown and significantly inhibited recovery in blood fed females. These data are a first step in evaluating drugs that might be eventually combined with, or substituted for ivermectin for future malaria parasite transmission control.

[Childhood acute lymphoblastic leukemia: 12 cases in Mali]

INTRODUCTION

Data about childhood acute lymphoblastic leukemia, the most common childhood malignancy in industrialized countries, are scarce in African publications. The purpose of this prospective, unicentric study were to assess the socio-demographic, clinic and laboratory characteristics of the children treated for lymphoblastic leukemia in our pediatric oncology unit in Gabriel Touré Teaching Hospital in Bamako, Mali.

PATIENTS AND METHODS

This study includes all children between 1 and 15 years old treated for cytologically documented acute lymphoblastic leukemia from January 1, 2007 to September 30, 2009.

RESULTS

A total of 12 cases including 8 boys and 4 girls (sex ration, 2) were treated during the study period. Mean age was 92 months. Age was less than 4 years old in 2 cases. 5 (41,7%) were between 5 and 9 years in 5 (41.7%) and between 10 to 15 years in five. At the time of presentation, 9 patients (75%) were in a cachectic state; 10 had lymphadenopathies, splenomegaly and hepatomegaly; and 2 had neurological involvement. The delay for definitive diagnosis was 5 months in 4 cases (33,3 %) and less than 5 months in the remaining cases. Initial white blood cell count was more than 50 000/mm3 in 10 cases and less less than 50 000/mm3 in 2 cases. All patients were treated using the LAL GFAOP protocol including LAL1 in 6 cases, LAL2 in 5 and LAL3 in 1. Treatment complications were included 6 undocumented infections in 6 cases, hemorrhage in 2 and severe anemia in 4. Four patients died. At 5 years follow-up, overall survival rate was 66,7%.

CONCLUSION

A multicentric study including a greater number of children is needed to increase understanding of the characteristics of childhood acute lymphoblastic leukemia in sub-Saharan Africa.