Correction: Safety of Seasonal Malaria Chemoprevention (SMC) with Sulfadoxine-Pyrimethamine plus Amodiaquine when Delivered to Children under 10 Years of Age by District Health Services in Senegal: Results from a Stepped-Wedge Cluster Randomized Trial.

[This corrects the article DOI: 10.1371/journal.pone.0162563.].

Safety of Seasonal Malaria Chemoprevention (SMC) with Sulfadoxine-Pyrimethamine plus Amodiaquine when Delivered to Children under 10 Years of Age by District Health Services in Senegal: Results from a Stepped-Wedge Cluster Randomized Trial.

BACKGROUND: It is recommended that children aged 3 months to five years of age living in areas of seasonal transmission in the sub-Sahel should receive Seasonal Malaria Chemoprevention (SMC) with sulfadoxine-pyrimethamine plus amodiaquine (SPAQ) during the malaria transmission season. The purpose of this study was to evaluate the safety of SMC with SPAQ in children when delivered by community health workers in three districts in Senegal where SMC was introduced over three years, in children from 3 months of age to five years of age in the first year, then in children up to 10 years of age. METHODS: A surveillance system was established to record all deaths and all malaria cases diagnosed at health facilities and a pharmacovigilance system was established to detect adverse drug reactions. Health posts were randomized to introduce SMC in a stepped wedge design. SMC with SPAQ was administered once per month from September to November, by nine health-posts in 2008, by 27 in 2009 and by 45 in 2010. RESULTS: After three years, 780,000 documented courses of SMC had been administered. High coverage was achieved. No serious adverse events attributable to the intervention were detected, despite a high level of surveillance. CONCLUSIONS: SMC is being implemented in countries of the sub-Sahel for children under 5 years of age, but in some areas the age distribution of cases of malaria may justify extending this age limit, as has been done in Senegal. Our results show that SMC is well tolerated in children under five and in older children. However, pharmacovigilance should be maintained where SMC is implemented and provision for strengthening national pharmacovigilance systems should be included in plans for SMC implementation. TRIAL REGISTRATION: ClinicalTrials.gov NCT 00712374.

[Changes in malaria prevalence and management of fevers from 2000 to 2012 in Casamance, Senegal]. / Évolution de la prévalence du paludisme et de la prise en charge des fièvres de 2000 et 2012 en Casamance, Sénégal.

Before 2006 in Senegal, in the absence of clinical diagnosis, all fever cases were considered as malaria and treated with chloroquine. Between 2004-2006, to face the dramatic increase of Plasmodium falciparum resistance to chloroquine, the combination of amodiaquine plus sulfadoxine-pyriméthamine was recommended for treatment. In 2006, rapid diagnostic tests were introduced and the treatment with a combination of artesunate plus amodiaquine (ASAQ) became the national recommendation for malaria treatment in 2007. This coincided with a decrease of the prevalence of malaria cases and change in fever management. Since 1995 in Mlomp in Casamance, thin and thick blood smear examination has systematically been done in patients with fever and clinical signs of malaria, and treatment with ASAQ given as experimental procedure. Between 2000 and 2012, 70,892 outpatients were attending the health center, and 51.2% of them for fever. Among these fever cases, 72.4% were suspected of malaria and 27.6% were identified as bacterial and viral infections. Confirmed malaria cases decreased dramatically from 1365 in 2000 to 53 in 2012. While comparing the 2 periods 2000-2006 and 2007-2012, the number of fever cases decreased by half, the number of fever identified as non malaria doubled and malaria treatment given decreased by 86%. Improvement of fever management in Mlomp has contributed to a better identification of their cause and to a decrease of inappropriate malaria treatments.

Microbial culturomics: paradigm shift in the human gut microbiome study.

Comprehensive determination of the microbial composition of the gut microbiota and the relationships with health and disease are major challenges in the 21st century. Metagenomic analysis of the human gut microbiota detects mostly uncultured bacteria. We studied stools from two lean Africans and one obese European, using 212 different culture conditions (microbial culturomics), and tested the colonies by using mass spectrometry and 16S rRNA amplification and sequencing. In parallel, we analysed the same three samples by pyrosequencing 16S rRNA amplicons targeting the V6 region. The 32 500 colonies obtained by culturomics have yielded 340 species of bacteria from seven phyla and 117 genera, including two species from rare phyla (Deinococcus-Thermus and Synergistetes, five fungi, and a giant virus (Senegalvirus). The microbiome identified by culturomics included 174 species never described previously in the human gut, including 31 new species and genera for which the genomes were sequenced, generating c. 10 000 new unknown genes (ORFans), which will help in future molecular studies. Among these, the new species Microvirga massiliensis has the largest bacterial genome so far obtained from a human, and Senegalvirus is the largest virus reported in the human gut. Concurrent metagenomic analysis of the same samples produced 698 phylotypes, including 282 known species, 51 of which overlapped with the microbiome identified by culturomics. Thus, culturomics complements metagenomics by overcoming the depth bias inherent in metagenomic approaches.

New Rickettsia sp. in tsetse flies from Senegal.

Tsetse flies are blood-sucking insects transmitting African trypanosomiasis. They are known to harbor also three intracellular bacteria that play important role in their lifecycle: Wigglesworthia glossinidia, Sodalis glossinidius and Wolbachia sp. We have studied 78 Glossina morsitans submorsitans collected in Senegal. In all studied flies we amplified genes of bacterium phylogenetically close to obligate intracellular pathogen Rickettsia felis, the agent of spotted fever in humans. We also visualized this rickettsia in the cells of tsetse flies by fluorescence in situ hybridization. The role of this probable fourth endosymbiotic bacterium of tsetse flies in Glossina lifecycle and possible pathogenecity for humans should be further investigated.

Amodiaquine dosage and tolerability for intermittent preventive treatment to prevent malaria in children.

Sulfadoxine-pyrimethamine with amodiaquine (SP-AQ) is a highly efficacious regimen for intermittent preventive treatment to prevent malaria in children (IPTc), but the amodiaquine component is not always well tolerated. We determined the association between amodiaquine dosage by body weight and mild adverse events (AEs) and investigated whether alternative age-based regimens could improve dosing accuracy and tolerability, using data from two trials of IPTc in Senegal, one in which AQ dose was determined by age and the other in which it was determined by weight category. Both dosage strategies resulted in some children receiving AQ doses above the recommended therapeutic range. The odds of vomiting increased with increasing amodiaquine dosage. In one study, incidence of fever also increased with increasing dosage. Anthropometric data from 1,956 children were used to predict the dosing accuracy of existing and optimal alternative regimens. Logistic regression models describing the probability of AEs by dosage were used to predict the potential reductions in mild AEs for each regimen. Simple amendments to current AQ dosing schedules based on the child's age could substantially increase dosing accuracy and thus improve the tolerability of IPTc using SP-amodiaquine in situations where weighing the child is impractical.

[Comparison of PCR, ELISA-CSP and direct microscopic observation methods for the detection of Plasmodium falciparum sporozoites in Anopheles gambiae M in Senegal]. / Comparaison des méthodes de la PCR, d'ELISA-CSP et d'observation microscopique directe pour la détection des sporozoïtes de Plasmodium falciparum chez Anopheles gambiae M au Sénégal.

A comparative study between the Enzyme-Linked Immuno Sorbent Assay (ELISA-CSP) for circumsporozoitic antigen detection method, the direct observation after dissection and the polymerase chain reaction (PCR) technique used to identify Plasmodium falciparum genomic DNA markers was carried out. This to evaluate the sensibility and the specificity of the PCR, for the determination of both sporozoitic index (ICSP) and the entomological inoculation rate (EIR). The study is conducted in laboratory on eighty six specimens of Anopheles gambiae M infected after being fed with the blood of a gametocytes carrier from Dielmo (Senegal). Salivary glands of forty-eight specimens randomly selected (test A) among the infected eighty six are microscopically observed after manual dissection for the sporozoites detection. The content of these salivary glands and the crushed head/thorax of the remaining 38 specimens (test B) are tested in ELISA-CSP and PCR. The positive and negative results obtained were recorded and summarized for each method. A pair-comparison of the results obtained with each method generally revealed a good sensibility and an excellent specificity The kappa coefficient (K) of test A indicated a "moderate" to "excellent" concordance between the three different methods performed. By using the crushed head/thorax sample, generally used to determine the transmission parameters (ICSP and EIR), the PCR/ELISA-CSP concordance was excellent. In the light of the values of sensibility and specificity obtained, this PCR is comparable to the other methods for the assessment of sporozoitic index and entomological inoculation rate.

New concepts for the old challenge of African relapsing fever borreliosis.

Relapsing fever, caused by spirochaetes belonging to the genus Borrelia, was once the cause of worldwide epidemic disease. This was largely through infection with the louse-borne form of the disease, caused by Borrelia recurrentis (louse-borne relapsing fever (LBRF)). During the last century, we have witnessed the demise of this infection, largely owing to improved standards of living and the introduction of the insecticide DDT, resulting in a reduction in the incidence of the body louse, the vector for relapsing fever. In areas of extreme poverty this disease persists, causing a significant burden of disease. It is now looking probable that this infection is caused by a louse-adapted variant of Borrelia duttonii, transmitted by Ornithodoros moubata 'soft' ticks in East Africa. Like LBRF, infection still causes impact, particularly affecting young children and pregnant women. Over recent years, the true burden of relapsing fever caused by infection with the closely related Borrelia crocidurae, transmitted by Ornithodoros sonrai ticks, has only just begun to emerge. Here, the current state of knowledge concerning relapsing fever in Africa is reviewed.

[A survey on the venomous snakes of the vicinity of Kindia (Guinea) and considerations on the treatment of snakebite]. / Etude epidémiologique des serpents venimeux et prise en charge des envenimations a Kindia (Guinée).

Between June and December 2004, snake collections were undertaken in eight villages of the vicinity of Kindia, an area of Guinea Conakry where the incidence of snakebite is among the highest reported in the world. A total of 916 specimens were collected, including 90 Elapidae (9.8 %) and 174 Viperidae (19.0%). The Black Mamba Dendroaspis polylepis was represented by eight specimens, i.e. almost 1% of the snakes collected. This species, which is considered as very rare in West Africa, appears common in this area of Guinea. The current difficulties for the treatment of snakebite due to the high increase of the cost of antivenom therapy are discussed.

[Epidemiologic evaluation of malaria in endemic areas]. / Evaluation épidémiologique du paludisme en zone d'endémie.

For decades malarial control has been implemented to control the impact of the disease on the health of populations living in endemic zones. The use of artemisinine combination therapy, intermittent preventive treatment for children and pregnant women, vector-control methods such as long-lasting insecticide-impregnated mosquito nets and indoor remanent insecticide spraying has proven to be effective. These practices have lead to such an extensive reduction of the malaria burden in some endemic areas that the objective of eradication that was unimaginable a few years ago is now back to the forefront. Regardless of the method chosen, careful evaluation and surveillance of its effectiveness in man is necessary. Achieving epidemiologic impact is the main goal of malaria control methods. The main measures for evaluation involve parasitological and clinical aspects of human malaria. The purpose of this article is to review methods used for epidemiologic evaluation of malaria burden.

Etude epidemiologique des serpents venimeux et prise en charge des envenimations a Kindia (Guinee)

De juin a decembre 2004 une collecte de serpents a ete organisee dans huit localites des environs de Kindia; une region de Guinee Conakry ou l'incidence des morsures de serpents et des deces qu'elles occasionnent sont parmi les plus elevees signalees dans le monde. Un total de 916 specimens a ete recolte; dont 90 Elapides (9;8) et 174Viperides (19;0). Le Mamba noir Dendroaspis polylepis etait represente par huit specimens; soit pres de 1de l'ensemble des serpents collectes. Cette espece consideree comme tres rare en Afrique de l'Ouest apparait comme frequente dans cette region de Guinee. Les difficultes actuelles de prise en charge des victimes de morsure de serpents provoquees par la forte augmentation du cout du traitement antivenimeux sont discutees

Antibody responses to a C-terminal fragment of the Plasmodium falciparum blood-stage antigen Pf332 in Senegalese individuals naturally primed to the parasite.

Previous studies have shown that antibodies from humans exposed continuously to malaria recognize the Plasmodium falciparum asexual blood-stage antigen Pf332. Here we analysed the antibody responses to a C-terminal fragment of Pf332, designated C231, in individuals from Senegal, by measuring the serum levels of immunoglobulin M (IgM), IgG class and subclass and IgE antibodies. IgG antibody reactivity with crude P. falciparum antigen was detected in all the donors, while many of the children lacked or had low levels of such antibodies against C231. The antibody levels increased significantly with age for both crude P. falciparum antigen and C231, and in the older age groups most of the donors displayed antibodies to C231. This was also true for IgM, IgE and IgG subclass reactivity against C231. Moreover, the ratio of IgG1/IgG2 was considerably lower for C231 than for crude P. falciparum antigen, and in age groups 10-14 and 15-19 years the levels of IgG2 against C231 even exceeded that of IgG1. The IgG2/IgG3 ratios suggest that C231 gives similar levels of IgG2 and IgG3, except for children aged 4-9 years, where IgG3 was higher. Raw IgM, IgG class and subclass and IgE antibody levels to C231 tended to be higher in those who did not experience a malaria attack, but following linear multivariate analysis the trends were not significant.

Molecular divergences of the Ornithodoros sonrai soft tick species, a vector of human relapsing fever in West Africa.

The soft tick Ornithodoros sonrai is recognized as the only vector of Borrelia crocidurae causing human relapsing fever in West Africa. Its determination has been exclusively based on morphological features, geographical distribution and vector competence. Some ambiguities persist in its systematics and may cause misunderstanding about West African human relapsing fevers epidemiology. By amplifying and aligning 16S and 18S rDNA genes in O. sonrai specimens collected from 14 distinct sites in Senegal and Mauritania, we showed the existence of four genetically different subgroups that were morphologically and ecologically identified as belonging to the same species. Within O. sonrai, intraspecific polymorphism was high (pairwise divergence from 0.2% to 16.4%). In all cases, these four subgroups formed a monophyletic clade sharing a common ancestor with East African soft ticks that transmit Borrelia duttoni human relapsing fever. From amplification of the flagellin gene of B. crocidurae we verified that all subgroups of O. sonrai were infected by B. crocidurae and may constitute vectors for this pathogen. All flagellin sequences were identical, refuting the hypothesis suggesting parallel evolution between O. sonrai and B. crocidurae. However, differences in infection rates were significant, suggesting different vector competences between subgroups of O. sonrai.

In vitro activity of iron-binding compounds against Senegalese isolates of Plasmodium falciparum.

OBJECTIVES: The in vitro activities of FR160, a synthetic catecholate siderophore, and two iron-binding agents, desferrioxamine and doxycycline, were evaluated against Plasmodium falciparum isolates. Correlations between these compounds and standard antimalarial drugs (chloroquine, quinine, amodiaquine, pyronaridine, artemether, artesunate, atovaquone, cycloguanil and pyrimethamine) were assessed to determine any degree of cross-resistance. METHODS: Between October 1997 and February 1998, and September and November 1998, 189 P. falciparum isolates were obtained in Dielmo and Ndiop (Dakar). Their susceptibilities were assessed using an isotopic, microwell format, drug susceptibility test. RESULTS: The 137 inhibitory concentrations (IC(50)) values of FR160 ranged from 0.1 to 10 microM and the geometric mean IC(50) was 1.48 microM (95% CI = 1.29-1.68 microM). The geometric mean IC(50) of doxycycline for 121 isolates was 18.9 microM (95% CI = 16.8-21.3 microM) and that of desferrioxamine for 73 isolates was 20.7 microM (95% CI = 17.3-24.8 microM). FR160 was significantly less active against the chloroquine-resistant isolates (P < 0.0001). The mean IC(50)s of doxycycline were significantly higher for the chloroquine-susceptible isolates than for the resistant parasites (P = 0.0447). There was a weak correlation between the responses to FR160, desferrioxamine or doxycycline and those to the other antimalarial compounds (r(2) < 0.22). CONCLUSIONS: The activities of FR160 and desferrioxamine, determined for P. falciparum clones, were confirmed against 137 isolates. The coefficients of determination between the responses to FR160, doxycycline or desferrioxamine and those to all the antimalarial drugs tested are too weak to suggest cross-resistance. FR160 could be a rationale partner to use in combination with doxycycline.

[The incidence of snakebite in a rural zone of southeastern Senegal]. / L'incidence des morsures de serpent en zone rurale au Sénégal oriental.

In order to complete an exploratory study on the risk of death due to snakebite in a rural zone of South-Eastern Senegal, we have carried out a survey to estimate the incidence of snakebites in the same population. The study made on a sample of almost 600 subjects showed an annual incidence of 677 bites per 100.000 inhabitants, that is one of the most important rate ever reported in the world until now. Based on these results and data collected previously on deaths due to snakebites in this same population, we provide an estimate of snakebite case fatality rate of 2.1% in this area of Senegal.

[Evaluating malaria attributable morbidity in endemic areas]. / Comment évaluer la morbidité attribuable au paludisme en zone d'endémie?

There are no specific clinical signs or symptoms of malaria. Fever attacks, anemia, or signs of severity like coma or respiratory distress cannot easily be attributed to malaria in people who are infected most of the time. Ascribing clinical manifestations to malaria is problematic in populations that are regularly exposed to the transmission of human plasmodia. The more transmission is intense and regular, the higher the prevalence of asymptomatic infections. In areas of intense and perennial malaria transmission, more than 90% of the population may be infected and the simple detection of a plasmodial infection is not enough to attribute clinical manifestations to malaria. Naturally acquired anti-malaria immunity permitting asymptomatic infections is incomplete and temporary. It is an obstacle to the estimation of the malaria burden in endemic areas. The positive association between parasite density and fever allows the attribution of clinical attacks to malaria. The relationship between parasitaemia and the risk of fever is not continuous. An age- and endemicity-dependent threshold effect of parasite density has been demonstrated and can be used to distinguish clinical attacks due to malaria from others. Clinical diagnosis and evaluation of malaria are problematic in three situations: in public health to estimate the malaria burden for health services, in clinical research to evaluate treatments or prophylactic measures (drug, vaccine, anti-vectorial devices), and in basic research on pathophysiology, immunology or genetic susceptibility to clinical malaria. No one diagnostic definition nor procedure for detecting cases is adequate for all three purposes. Case detection may be passive (in health structures for example) or active (in population). The choice of methods for diagnosis and recruitment depends on the objectives and whether a "pragmatic" or "explicative" approach is used. The radical differences between these approaches are often unsuspected or ignored.

Genetic study of ICAM1 in clinical malaria in Senegal.

Many genes have been implicated in the risk of severe malaria, generally based on candidate gene studies in case/control populations. Among these genes, there has been conflicting reports for the implication of a variant of the intercellular adhesion molecule 1 (ICAM1), ICAM1(Kilifi), in the risk of severe malaria, while in vitro studies provided independent support for a functional role of this variant. In order to explore the possible implication of ICAM1 in the susceptibility/resistance to malaria and to try to understand its clinical relevance in the disease process, we have conducted linkage and association studies of ICAM1 in two Senegalese villages located in regions of endemic malaria. We explored the full genetic variability of ICAM1, and tested it on several clinical malarial traits which are under genetic control, focusing principally on variables related to the parasite density and the number of malarial attacks. Our study provides no evidence for a role of ICAM1 variability on the malarial phenotypes studied.

[West African tick-borne relapsing fever]. / La fièvre récurrente à tiques d'Afrique de l'Ouest.

West African tick-borne relapsing fever is an endemic disease due to Borrelia crocidurae. The tick Alectorobius sonrai is the only known vector of this bacterium. Several species of rodents and insectivores may be reservoir for this spirochete. The geographic distribution of Borrelia crocidurae is not well known. The zone where the presence of the vector has been recorded is situated in Sahelian regions, from Mauritania and northern Senegal up to Chad. In Senegal, it has been shown that the persistence of drought is responsible for a considerable spread of tick-borne relapsing fever to the south. Few epidemiological data are available about West African tick-borne relapsing fever. In Senegal, epidemiological investigations indicate that Borrelia crocidurae is a major cause of morbidity (annual incidence rate of 5.1%). The relapsing nature of tick-borne borreliosis depends on Borrelia's antigenic variability. Except relapsing febrile episodes, this illness presents no pathognomonic signs. Borrelia crocidurae relapsing fever is generally benignant but neurologic or ocular complications can occur. The diagnosis of tick-borne relapsing fever is made by demonstrating the presence of Borrelia in peripheral blood in thick smear, by intraperitoneal inoculation of mice or more recently with quantitative buffy coat method (QBC test). The best treatment for relapsing fever is tetracycline or doxycycline. When tetracyclines are contraindicated, the alternative is erythromycin. In neurologic complications, the effective treatment is intravenous penicillin G or ceftriaxone. West African tick-borne relapsing fever must be systematically mentioned in case of fever in a patient returning from the endemic area.

Increased frequency of malaria attacks in subjects co-infected by intestinal worms and Plasmodium falciparum malaria.

The influence of intestinal worm infections on malaria was studied in individuals from Dielmo, Senegal in 1998. Results suggest that, compared with those infected, individuals free of helminths had the same degree of protection against malaria as that provided by sickle-cell trait, the most potent factor of resistance to malaria identified to date.