Dynamics of PfEMP1 Antibody Profile From Birth to 12 Months of Age in Beninese Infants.

BACKGROUND: Plasmodium falciparum-infected erythrocytes bind to specific endothelial cell receptors via members of the PfEMP1 family exported onto the erythrocyte surface. These interactions are mediated by different types of cysteine-rich interdomain region (CIDR) domains found in the N-terminal region of all PfEMP1. CIDRα1 domains bind endothelial protein C receptor (EPCR), CIDRα2-6 domains bind CD36, whereas the receptor specificity of CIDRß/γ/δ domains is unknown. METHODS: In this study, we investigated the level of immunoglobulin (Ig)G targeting the different types of PfEMP1 CIDR during the first year of life. We used plasma collected longitudinally from children of pregnant women who had been followed closely through pregnancy. RESULTS: Antibodies to CIDRα1 domains were more frequent in cord blood compared with antibodies to CIDRα2-6 domains. Higher IgG levels to EPCR-binding CIDRα1 variants positively correlated with the timing of first infections. Antibodies to all PfEMP1 types declined at similar rates to the point of disappearance over the first 6 months of life. At 12 months, children had acquired antibody to all types of CIDR domains, mostly in children with documented P falciparum infections. CONCLUSIONS: These observations agree with the notion that the timing and phenotype of first P falciparum infections in life are influenced by the immune status of the mother.

[Assessment of a rapid diagnostic test and portable fluorescent microscopy for malaria diagnosis in Cotonou (Bénin)]. / Évaluation d'un test de diagnostic rapide et d'un microscope à fluorescence portable pour le diagnostic du paludisme à Cotonou (Bénin).

The aim of the study was to determine the accuracy of a rapid diagnostic test (SD Bioline Malaria Ag P.f/ Pan®) and fluorescent microscopy (CyScope®) in confirming presumptive malaria diagnosis in Cotonou. Thick blood smear was used as the reference technique for comparison. Testing was conducted on persons between the ages of 6 months and 70 years at two hospitals from June to October 2010. If malaria was suspected in the sample by the nurse based on clinical findings and sent to laboratory for confirmation, one thick smear, one rapid diagnostic test and one slide for the fluorescent microscopy were performed. All tests were read in hospital laboratories involved with the quality control of thick blood smear in the parasitology laboratory of National University Hospital of Cotonou. A total of 354 patients with clinical diagnosis of malaria were included. Malaria prevalence determined by thick smear, rapid diagnostic test and fluorescent microscopy was 22.8%, 25.4%, and 25.1% respectively. The sensitivity, specificity, positive and negative predictive values compared to the thick smears were 96.3, 95.6, 86.7, and 98.9% for rapid diagnostic test; and 97.5, 96.7, 89.8, and 99.27% for fluorescent microscopy. With these performances, these tests meet acceptability standards recommended by WHO for rapid tests (sensitivity > 95%). These two methods have advantages for the confirmation of malaria diagnosis in peripheral health structures that lack the resources to conduct diagnosis confirmation by the thick blood smear.

Life-history traits indicate local adaptation of the schistosome parasite, Schistosoma mansoni, to its snail host, Biomphalaria pfeifferi.

The digenean trematode Schistosoma mansoni causes schistosomiasis (Bilharziasis), a significant human disease especially in sub-Saharan Africa. We tested local adaptation of this parasite to its intermediate host, the freshwater snail Biomphalaria pfeifferi, by exposure of S. mansoni to B. pfeifferi from one sympatric and four allopatric populations and measurement of life-history traits of both species over time. The pre-patent period, infection rate, and cercarial production of the parasite were determined, and the shell diameter, fecundity, and survival of the snail host were determined. The results provide evidence for local adaptation of S. mansoni to its sympatric snail host: the pre-patent period was the shortest, the cercarial production was moderate and accompanied by a higher survival rate, the growth was greater during the pre-patent period, and the fecundity was greater during the pre-patent period. The greater growth and fecundity of sympatric B. pfeifferi suggests the presence of growth and fecundity compensation. These fitness traits are relevant to energy allocation of the snail host and to the transmission strategy of the schistosome parasite.

[Clinical study of tolerance and effectiveness of a F(ab')(2) polyvalent antienom for African snake bites in Kindia, Guinea]. / Étude clinique de la tolérance et de l'efficacité d'un sérum anti-ophidien polyvalent F(ab')(2) pour l'Afrique à Kindia, Guinée.

An open, pragmatic, phase IV clinical trial was undertaken to measure tolerance and assess the effectiveness of Antivipmyn® Africa, antivenom composed of lyophilized F(ab')(2) fragments of immunoglobulin G in field conditions. The study was conducted at the Institut Pasteur of Guinea (IPG) from August 2009 to February 2010. Two hundred twenty-eight victims of snakebites presented at the processing center of the IPG during this period, including one hundred fifty (65.8%) envenomations, mostly young men. One hundred twenty-four of them (82.7%) suffered from viper envenomations and 26 (17.3%) from elapid ones. All patients were treated by intravenous Antivipmyn® Africa, averaging 1.4 (± 1.0) vials, more in patients with neurotoxic envenomation than others (P < 10(-5)). Four patients (2.7%), showing cobralike envenomation, died shortly after their arrival at the IPG despite the administration of the antivenom. Ten patients showed mild side effects (rash or pruritus), out of which 5 (3.3%) were probably due to treatment. This study confirms the efficacy and safety of Antivipmyn® Africa.

[A randomized clinical trial comparing the effectiveness and tolerability of artemisinine-naphthoquine (Arco®) and artemether-lumefantrine (Coartem®) in the treatment of uncomplicated malaria in Benin]. / Essai clinique randomisé comparant l'efficacité et la tolérance de la combinaison artémisinine-naphthoquine (Arco®) et artéméther-luméfantrine (Coartem®) dans le traitement du paludisme simple au Bénin.

The Ministry of Health recommended in Benin, since 2004, artemisinin-based combination, artemether-lumtefantrine (Coartem®), therapy for the treatment of uncomplicated malaria. To resolve the difficulties related to observance, we are interested in a new combination, artemisinin-naphthoquine (Arco®). A study was conducted to assess and compare the efficacy and tolerability of the fixed combination artemisinin (125 mg)-naphthoquine (50 mg), a single-dose drug, administered one day versus artemether (20 mg)-lumefantrine (120 mg).The clinical assessment was a single-blinded, two-arm, randomized trial comparing Arco® combination as a single-dose regimen and three-day regimen of Coartem® for the treatment of uncomplicated falciparum malaria, from july to october 2008 and may to september 2009, with 28 days of follow-up in children. PCR genotyping was used to classify re-infection or recrudescence. The primary outcome measures for efficacy were cure rates on days 3, 7, 14, 21 and 28. Secondary outcomes included parasite clearance time and fever clearance time. The main outcome measures for safety were incidences of post-treatment clinical and laboratory adverse events. A total of 174 patients (84 in Arco® group and 90 in Coartem® group) were evaluated for clinical and parasitological outcomes. The cure rate was 98.8% for Arco® and 100% for Coartem® on day 28, with no statistically significant difference. Fever clearance was obtained within 24 hours in both groups. The parasite clearance is obtained at 48 hours in Arco® group and at 60 hours in Coartem® group. Both treatments were well tolerated without major side effects. This study therefore concluded that the combination of artemisinin-naphthoquine is as effective and well tolerated as the combination artemether-lumefantrine in the treatment of uncomplicated malaria in Benin children. This medication administered in single dose is therapy of choice to reduce compliance problems during malaria treatment and also to facilitate community-based care of malaria.

[Report of the 4th International Conference on Envenomations by Snakebites and Scorpion Stings in Africa, Dakar, April 25-29, 2011]. / 4(e) Conférence internationale sur les envenimations par morsures de serpent et piqûres de scorpion en Afrique : Dakar, 25-29 avril 2011.

The authors present a summary of the proceedings and the recommendations of the Fourth International Conference on Envenomations by Snakebites and Scorpion Stings in Africa, held from 25 to 29 April 2011 in Dakar. After a two-day workshop for Senegalese health personnel on the most relevant aspects of the management of envenomations, about 270 participants met to share their experiences in the field. Nearly a hundred oral and poster presentations were made on the epidemiology of snakebites and scorpion stings in Africa, the composition and action of venoms and the manufacture and use of antivenoms. The last day was devoted to an institutional debate involving experts, representatives of national health authorities and concerned professionals (physicians, pharmacists, nurses and traditional healers) as well as members of the pharmaceutical industry to discuss and elaborate a set of recommendations. It was agreed that it is necessary to improve knowledge of the epidemiological situation by case reporting. Quality control of antivenoms and procedures for their registration at the level of national health authorities should aim at improving the distribution of safe and effective antivenoms in peripheral health centers for the better assessment of victims. It was also recommended that adequate training should be provided for health personnel in all aspects of medical management of envenomations. Equitable distribution of funding and the establishment of a network of African experts were also discussed in the conference.

[Epidemiologic and medico-clinical aspects of the cholera outbreak in the Littoral department of Benin in 2008]. / Aspects épidémiologiques et médico-cliniques de l'épidémie de choléra dans le département du Littoral au Bénin en 2008.

OBJECTIVE: The purpose of this study was to determine epidemiological and medico-clinical features of the cholera outbreak that occurred in the Littoral department of Benin in 2008. METHODS: This cross-sectional descriptive analytic study was based on review of a total of 404 patient files. Study data included patient identity, clinical and therapeutic features and treatment outcome. Ten randomly selected patients participated in a focus group discussion. Decision-makers in charge of managing the outbreak and medical personnel that provided care were thoroughly debriefed and 10 affected areas were visited. Data were analyzed using EPI INFO 3.3.2 and EXCEL 2007. RESULTS: The outbreak started in Cotonou on 26 July 2008 and lasted for 21 weeks. Mean patient age was 23.72 +/- 14.80 years. Attack rates per district ranged from 15.86 to 172.98 per 100.000. Attack rates in Agbodjèdo, Hlacomey and Enagnon districts were significantly higher (p<10(-4)) than in other districts. The case fatality rate was 0.24 per 100. Crowded living conditions along the banks of the Cotonou lagoon along with poor sanitation and inadequate drinking water supply explain the endemicity of cholera in Cotonou. Vibrio cholerae O:1 was detected in 19 out of 36 stool samples. All strains were sensitive to ciprofloxacine but resistant to cotrimoxazole. Diarrhea was a consistent feature in all patients, along with vomiting in 88.11% and severe dehydration in 39.35%. Treatment involved oral rehydration, parenteral rehydration and antibiotherapy in 99.50%, 85% and 97.77% patients respectively. Antibiotherapy consisted of doxycycline for adult cases and amoxicilline for pregnant women and children. The duration of stay at the treatment center was significantly longer for patients with severe dehydration (p<10(-4)). CONCLUSION: Enhancing basic sanitation and access to drinking water and intensifying information campaigns on the need for healthy living behavior especially in districts located near the banks of Cotonou lagoon are needed to improve cholera prevention in the Littoral department in Benin.

[Determination of prevalence and etiology of anemia during pregnancy in southern Benin, in conjunction with revision of national management policy]. / Prévalence et etiologies de l'anémie chez la femme enceinte au sud Bénin au moment du changement de politique nationale de prise en charge.

BACKGROUND: Anemia during pregnancy is a serious public health problem. Control requires identification of the underlying etiology. The objective of this study carried out in conjunction with revision of the national policy for the protection of pregnant women in Benin was to determine the prevalence and etiology of anemia. METHODS: From October 2006 to April 2007, 300 pregnant women were examined at two maternities in Ouidah, Benin. Sociodemographic and environmental characteristics, dietary data, behavioral practices, and history of malaria infection during pregnancy were collected. Blood and stool samples were tested for the presence of malaria parasites and intestinal worms respectively. Hemoglobin and ferritinemia levels were also determined. RESULTS: The prevalence of anemia (Hb < 11 g/dL) was 65.7% while that of malaria and intestinal worms was 4.3% and 8% respectively. Iron deficiency was not found. A borderline significant correlation was found between helminthiasis and anemia. No correlation was found between anemia and malaria. These findings indicate that kits progressively introduced by the health system during the study period provided relatively effective care. CONCLUSION: This study demonstrates a high prevalence of moderate anemia during pregnancy and suggests that it is mainly due to intestinal helminthiasis. These findings underline the importance of preventive antihelminthic treatment during pregnancy.

[Evaluation of the quality of malaria management during the transition period of political change in Benin]. / Evaluation de la qualité de la prise en charge des paludismes au cours de la période de transition de changement de politique au Bénin.

The purpose of this retrospective study in 2006 was to evaluate the impact of control activities implemented within the framework of "Roll Back Malaria (RBM) program" on the medical indicators. Study was based on review of the files of children between 0 and 14 years treated in pediatric outpatient or hospital facilities for malaria confirmed by the thick drop smears from January 1, 2001 to December 31, 2005. A total of 1589 files were reviewed. Data was collected using a standardized form. From 2001 to 2005, the number of children treated for uncomplicated malaria seesawed while the number treated for complicated malaria increased. Proper treatment of uncomplicated malaria went from 58.78% in 2001 to 15.38% in 2005. In all study years, quinine was the most-used drug for uncomplicated malaria. Treatment of complicated malaria also improved from 40% in 2001 to 90.61% in 2005. Although malaria-related mortality remained low (< 2%), the death rate increased from 2001 to 2005. Proper treatment of uncomplicated malaria still poses a challenge using quinine indicated in complicated malaria cases. Based on these findings, it appears urgent for the MNCP to intensify training activities at the medical facilities. This is the only means of achieving the strategic goals of "initiative RBM".

[Value of rapid tests for diagnosis of malaria in Benin]. / Valeur des tests rapides pour le diagnostic du paludisme au Bénin.

Reliable diagnosis of malaria is essential in malaria endemic areas. The purpose of this study was to compare the performance of rapid diagnostic tests to that of the thick and thin blood smear techniques conventionally used for diagnosis of malaria. A total of 84 patients presenting malaria symptoms were included and tested for malaria. Results of blood smears and rapid tests performed blindly in external labs were compared with results of blood smears and PCR done in our reference laboratory. Sensitivity, specificity, positive and negative predictive value were determined using PCR as the gold standard. Results of the rapid diagnostic test were much better than those of the microscopic technique performed in external labs, particularly with regard to true positivity. The blood smear technique in external labs led to 12 false positive diagnoses and was associated with a lower positive predictive value than the rapid test: 58.6% vs. 85.7%. The sensitivity and specificity of the rapid test were also higher than those obtained in external laboratories using blood smear techniques: 90.0% and 95.3% respectively versus 85.0% and 81.2% respectively. The results of this study indicate that the rapid test is more reliable than microscopy and that its use would improve malaria diagnosis. Risks factors for false diagnosis and limitations of the different diagnostic techniques are discussed.

[Management of malaria in Benin: evaluation of the practices of healthcare professionals following the introduction of artemisinin derivatives]. / Prise en charge du paludisme au Bénin: évaluation des pratiques professionnelles suite à l'introduction des dérives d'artémisinine.

In 2004 the policy for malaria management in Benin changed when the National Malaria Coordination Program (NMCP) introduced artemisinin-based combination therapy (ACT) for treatment of uncomplicated malaria. Up to that time, chloroquine had been used for first-line therapy against uncomplicated malaria and sulfadoxine pyrimethamine had been used in case of failure. Artemisinin derivatives have been used for monotherapy in Benin since 2002. The purpose of this transverse study carried out among public and private centers in Cotonou from March 16 to May 17, 2005 was to determine the impact of the switch to ACT on the practices of healthcare professionals. Medical centers were randomly selected from each stratum after identification and stratification of all facilities in the healthcare pyramid. A survey questionnaire was sent to healthcare workers. A total of 690 health workers responded to the questionnaire. Most responders (95.5%) were familiar with artemisinin but a lower percentage (89.6%) prescribed them. Responders were less knowledgable about ACT drugs and Coartem was the best known combination in the minds of prescribers. Biological diagnosis was available for 50% of patients. Artemisinine (derivates) were mainly prescribed as a second choice treatment and as monotherapy whether for severe or uncomplicated malaria. They were prescribed to pregnant women in 34.6% of the cases. Dosage was incorrect in 26.1% of cases in adults and 20.9% of cases in children. These findings indicate that more effort is needed to inform healthcare workers. This is especially urgent since the country is now considering revising its malaria management policy to make ACT available at all levels of the healthcare system. An effective information campaign must be set up to ensure that health workers and drug retailers throughout the country are duly informed of the new malaria treatment policy.

[Report of the 3rd International Conference on Envenomations in Africa]. / Troisième Conférence internationale sur les envenimations en Afrique. Brazzaville, 15-17 novembre 2007.

The 3rd International Conference on Envenomations was held in Brazzaville from 15 to 17 November; 2007. At this meeting, updating of epidemiological and treatment information on envenomations in Africa were presented. A round table concluded the conference drawing contributors' main recommendations. One of these recommendation pointed out the need to treat the problem of envenimations at a regional level by creating a group of experts in charge of considering the priorities as well as identifying relevant strategies of management, ensuring the plea and finding the financing.

Clinical trial of an F(ab')2 polyvalent equine antivenom for African snake bites in Benin.

We report the results of a trial designed to measure the safety and efficacy of African Antivipmyn, a new freeze-dried polyvalent equine F(ab')(2)-based antivenom. We tested 289 envenomations. After treatment, 19% of treated patients had undesirable events, all benign. A possible adverse effect was attributed to this antivenom in 11% of the patients. Bleeding was observed in 48% of the patients; it stopped within 2 hours after treatment with antivenom in 60% of the patients. Blood incoagulability was observed in 80% of the patients. Restoration of coagulation was attained within 4 hours in 60% of the patients. Nine patients died; 6 arrived at the hospital in the final stage of complications and 5 arrived at the hospital more than 60 hours after the bite. The value of blood coagulation tests in diagnosis of envenomation and bleeding as an indicator of renewal of treatment are emphasized.

[The re-emergence of the human African trypanosomiasis in Kerou, Benin]. / Le réveil de la trypanosomose humaine africaine à Kérou, Bénin.

Located in the northern part of Bénin, the district of Kérou is an historical HTA focus of the 60s formerly called the "Atacora focus". This survey was conducted in 2001 to determine the prevalence of HAT in Kérou. The methodology consisted in a cross-sectional survey based on random sampling with two levels of stratification. 3367 persons were included (i=5%). After a screening based on CATT test with total blood test, the examination of trypanosomae was performed with QBC on the subjects that have some persistent antibodies above serum dilution at 1/4, followed by lumbar puncture. For 3367 surveyed subjects, the CATT seroprevalence test with total blood sample is 4.2% and it is 2.4% with serum dilution at 1/8. The research of trypanosomae with QBC is positive in 48 patients and the prevalence is 1.4%. The community survey conducted among 106 positive persons with CATT test serum at 1/4 dilution has revealed that 71 (67%) persons have never left the area since their birth. The HAT is actually emerging in Atacora district in the north of Bénin, especially in Kérou.

Prevalence and risk-factors for Helicobacter pylori infection in urban and rural Beninese populations.

In total, 446 healthy individuals (240 in urban and 206 in rural environments, respectively) were selected from 96 households, based on cluster sampling of residential location. Demographic, sociological and environmental data were collected by face-to-face interviews using a standard questionnaire. Infection with Helicobacter pylori was assessed by detection of anti-H. pylori IgG serum antibodies. The prevalence of H. pylori antibodies was 75.4% in the urban population and 72.3% in rural (village) residents (p 0.459). No association was found between infection and age, gender, education level, size of household, economic activity or source of drinking water. The infection rate was higher in children whose parents were both infected, and also in children whose mother was infected (p < 0.001). By logistic regression analysis, the density of occupation of sleeping accommodation (more than three persons sharing a room; 95% odds ratio (OR) = 9.82 (4.13-23.31), p < 0.001), and the mother's status within the household (95% OR = 3.85 (1.53-9.67), p 0.003), were independent predictors for H. pylori infection. The 74% seroprevalence of H. pylori infection found in healthy Beninese individuals is similar to that reported previously from other parts of sub-Saharan Africa. Family contact with infected persons and crowded living conditions were associated with increased risk of infection. These findings are consistent with intra-familial H. pylori transmission and suggest that improvement of living conditions should be protective against infection.

Round table of November 20th, 2004: recommendations for improving the management of envenomations.

The round table underlines the necessity to follow the epidemiological and clinical surveys in order to precise the incidence and severity of snakebites and inform the health authorities that could thus arrange to take in charge envenomation accidents. Simple therapeutic protocols adapted to epidemiological and clinical data will be elaborated according to each level of health pyramid. They will be included in the health staff training and integrate traditional practitioners whose role must be clearly defined. An experimental and clinical validation must confirm its appropriateness with countries and victims needs. Some microeconomic surveys are necessary to identify adapted funding and thus improve their accessibility

[Evaluation of a new polyvalent antivenom against snakebite envenomation (Inoserp® Panafricain) in two different epidemiological settings: Northern Benin and Maritime Guinea]. / Évaluation d'un nouvel antivenin polyvalent contre les envenimations ophidiennes (Inoserp(®) Panafricain) dans deux contextes épidémiologiques: le Nord Bénin et la Guinée Maritime.

OBJECTIVES: The authors evaluated the safety and efficacy of Inoserp(®) Pan Africa, a new polyvalent antivenom composed of highly purified and lyophilized fragments of F(ab')2 immunoglobulins, recently registered in Benin and Guinea. METHODS: We treated 100 patients in northern Benin (Atacora) and 109 in Maritime Guinea (Kindia) with confirmed envenomation. Treatment consisted of intravenous administration of 1 vial for uncomplicated envenomation, and 2 vials for hemorrhagic or neurotoxic envenomation. The dose was repeated when bleeding or signs of neurotoxicity persisted or appeared. RESULTS: In Atacora, on arrival at the hospital, 90% of patients had incoagulable blood, and 50% were bleeding. The resolution of these bleeding disorders was obtained in less than 3 hours for 50% of the patients and in less than 24 hours for 98%. Four patients died. In Kindia, 96 patients (88%) presented viper bites with pain + edema and 13 (12 %) others showed elapid (ptosis, dyspnea) envenomation. One patient bitten by a member of the Elapidae family, died despite early treatment. In Benin, protocol deviations for 60% of patients led to significant underdosing of the antivenom; the proportion was much lower (2%) in Guinea. Signs of intolerance after Inoserp(®) Pan Africa administration were reported in 8% of patients. All these symptoms were mild and disappeared rapidly after an antihistamine or corticosteroid treatment. CONCLUSION: Treatment using intravenous Inoserp(®) Pan Africa appeared to be well tolerated and effective against snakebite envenomation in both epidemiological settings.