[Squamous cell carcinoma secondary to Buruli ulcer in West Africa]. / Carcinomes épidermoïdes sur cicatrices d'ulcère de Buruli en Afrique de l'Ouest.

BACKGROUND: Buruli ulcer is an infection caused by Mycobacterium ulcerans occurring in tropical areas. In West Africa, it is an emerging threat mainly affecting children aged under 15years. This chronic disease is complicated by dystrophic scars in which squamous cell carcinoma can occur in the long term. PATIENTS AND METHODS: This is a retrospective study of squamous cell carcinomas in Buruli ulcer scars seen at the Treichville University Hospital (Abidjan, Ivory Coast) over a five-year period. RESULTS: During the study period, 8cases were observed and concerned young adults presenting Buruli ulcer in their childhood. Tumours were restricted to the limbs, with loco-regional invasion. Treatment was primarily surgical. Four of the patients died. DISCUSSION: The risk of recurrence of cancer in these scars remains poorly evaluated, highlighting the importance of long-term monitoring strategies for human patients in order to ensure rapid identification of any changes in Buruli ulcer scars.

Target-site resistance mutations (kdr and RDL), but not metabolic resistance, negatively impact male mating competiveness in the malaria vector Anopheles gambiae.

The implementation of successful insecticide resistance management strategies for malaria control is currently hampered by poor understanding of the fitness cost of resistance on mosquito populations, including their mating competiveness. To fill this knowledge gap, coupled and uncoupled Anopheles gambiae s.l. males (all M form (Anopheles coluzzii)) were collected from mating swarms in Burkina Faso. This multiple insecticide resistant population exhibited high 1014F kdr(R) allele frequencies (>60%) and RDL(R) (>80%) in contrast to the Ace-1(R) allele (<6%). Kdr heterozygote males were more likely to mate than homozygote resistant (OR=2.36; P<0.001), suggesting a negative impact of kdr on An. coluzzii mating ability. Interestingly, heterozygote males were also more competitive than homozygote susceptible (OR=3.26; P=0.006), suggesting a heterozygote advantage effect. Similarly, heterozygote RDL(R)/RDL(S) were also more likely to mate than homozygote-resistant males (OR=2.58; P=0.007). Furthermore, an additive mating disadvantage was detected in male homozygotes for both kdr/RDL-resistant alleles. In contrast, no fitness difference was observed for the Ace-1 mutation. Comparative microarray-based genome-wide transcription analysis revealed that metabolic resistance did not significantly alter the mating competitiveness of male An. coluzzii mosquitoes. Indeed, no significant difference of expression levels was observed for the main metabolic resistance genes, suggesting that metabolic resistance has a limited impact on male mating competiveness. In addition, specific gene classes/GO terms associated with mating process were detected including sensory perception and peroxidase activity. The detrimental impact of insecticide resistance on mating competiveness observed here suggests that resistance management strategies such as insecticide rotation could help reverse the resistance, if implemented early.

Assortative mating in mixed swarms of the mosquito Anopheles gambiae s.s. M and S molecular forms, in Burkina Faso, West Africa.

The molecular form composition of Anopheles gambiae Giles s.s. (Diptera: Culicidae) mating swarms and the associated mating pairs (copulae) were investigated during two rainy seasons (July to October, 2005 and July to November, 2006) in the villages of Soumousso and Vallée du Kou (VK7). Although the habitats of these villages differ markedly, sympatric populations of M and S molecular forms of An. gambiae s.s. occur in both places periodically. The main aim was to assess the degree to which these molecular forms mate assortatively. In Soumousso, a wooded savannah habitat, the majority of swarm samples consisted of only S-form males (21/28), although a few M-form males were found in mixed M- and S-form swarms. In VK7, a rice growing area, the majority of swarm samples consisted of only M-form males (38/62), until October and November 2006, when there were nearly as many mixed-form as single-form swarms. Overall, ∼60% of M- and S-form swarms were temporally or spatially segregated; the two forms were effectively prevented from encountering each other. Of the remaining 40% of swarms, however, only about half were single-form and the rest were mixed-form. Of the 33 copulae collected from mixed-form swarms, only four were mixed-form pairs, significantly fewer than expected by random pairing between forms (χ(2) = 10.34, d.f. = 2, P < 0.01). Finally, all specimens of inseminated females were of the same form as the sperm contained within their spermatheca (n = 91), even for the four mixed-form copulae. These findings indicate that assortative mating occurs within mixed-form swarms, mediated most probably by close-range mate recognition cues.

[Bifocal Buruli ulcer: multiple cephalic lesions after initiation of medical treatment]. / Ulcère de Buruli à début bifocal: multiples lésions céphaliques après instauration du traitement médical.

BACKGROUND: Buruli ulcer (BU) denotes a cutaneous infection by Mycobacterium ulcerans endemic in certain tropical and subtropical regions. Treatment may be either medical and surgical or else purely medical for early lesions. The literature contains reports of several cases of transient aggravation of BU following initiation of medical treatment. We report a case observed in the Ivory Coast, one of the areas with the highest prevalence of BU worldwide. The distinguishing features of our case are the early onset of this paradoxical reaction and the multiple cephalic site of lesions. PATIENTS AND METHODS: A 4-year-old child with no prior medical history was referred for two painless ulcerative cutaneous nodules. Incubation of samples from the edges of these lesions revealed the presence of acid-alcohol resistant bacilli (AARB), which were shown by PCR to be M. ulcerans, the causative agent in BU. Treatment consisted of levofloxacin (100mg/d) and rifampicin (150mg/d) for 8weeks. After 7days of medical treatment, seven painless nodules appeared on the patient's scalp. Further PCR for these lesions confirmed the presence of M. ulcerans. The same medical therapy was maintained and after 54days of treatment, all lesions had been healed. DISCUSSION: The originality of this case rests on two features: the bifocal aspect of the lesions, which is uncommon, and the early development of cephalic predominance that occurred after the start of drug treatment. While cases of lesions secondary to initiation of medical therapy have already been described, such lesions generally occurred after at least 2months of treatment and did not involve the head.

Residual malaria transmission: Magnitude and drivers of persistent Plasmodium infections despite high coverage of control interventions in Burkina Faso, West Africa.

This study collected baseline data on malaria vectors to characterize the drivers and the factors of persistent malaria transmission in two villages in the western part of Burkina Faso. Mosquitoes were collected in each village using the Human landing catch and pyrethrum spray catch and identified using the morphological keys. Molecular analyses were performed for the identification of An. gambiae complex species, the detection of Plasmodium infection and kdr-995F mutation. Anopheles mosquito larvae were also collected in the same villages, reared to adult's stage for the WHO tube and cone tests performing. The physical integrity of the LLINs already used by people in each village was assessed using the proportional hole index (pHI). An. gambiae s.l. was the main malaria vector accounting for 79.82% (5560/6965) of all collected mosquitoes. The biting pattern of An. gambiae s.l. was almost constant during the survey with an early aggressiveness before 8 p.m. and later biting activity after 6 a.m. The EIR varied from 0.13 to 2.55 infected bites per human per night (average: 1.03 infected bites per human per night). An. gambiae s.l. populations were full susceptible to Chlorpyrifos-methyl (0.4%) and Malathion (5%) with high kdr-995F mutation frequencies (>0.8). The physical integrity assessment showed high proportion of good nets in Santidougou compared to those collected in Kimidougou. This study highlighted a persistence of malaria transmission despite the intense use of vector control tools as LLINs and IRS by correlating mosquito biting time and human behavior. It provided a baseline guide for the monitoring of the residual malaria transmission in sub-Saharan Africa and encouraging the development of new alternative strategies to support the current malaria control tools.

[Hysterectomy: indications and advantages of the vaginal route in Mali]. / Hystérectomie: indications et avantages de la voie vaginale au Mali.

The purpose of this report was to determine the frequency of hysterectomy and describe its indications and outcomes. A retrospective, descriptive study related to active hysterectomy of was conducted at the reference health centre of commune V in Bamako, Mali from January 1st, 2004 to December 31st, 2008. All hysterectomy patients with complete medical files were included. A total of 172 files were identified including 152 that were complete. Hysterectomy accounted for 1.38% of all interventions during the study period. The procedure was carried out in emergency in 0.14% and electively in 13.39%. Mean patient age was 47.9 +/- 11.7 years; 89 patients were older than 45 years. The indications for hysterectomy were complicated uterine fibroids in 82 patients, genital prolapse in 44, adenomyosis in 10, obstetrical hysterectomy in 13 and cervical dysplasia in 3. The abdominal route was used in 100 patients (65.8%) and the vaginal rout in 52 (34.2%). The duration of the procedure and hospital stay was longer after hysterectomy by the abdominal (p<0.05). Perioperative complications were observed in 17% of patients after abdominal hysterectomy versus 7.69% after vaginal hysterectomy. Two maternal deaths due to hemorrhagic shock were observed after obstetrical hysterectomy. Hysterectomy is a frequent intervention that is not without complication risks. Choice of route depends on the indication and skill of the operator. Although endoscopic surgery is still difficult to perform in developing countries, development of vaginal hysterectomy is necessary to reduce perioperative complications.

[Management of patients with Covid 19: analysis of prescription drugs at Gabriel Touré University Hospital]. / Prise en charge des patients atteints de Covid 19 : analyse des prescriptions médicamenteuses au CHU Gabriel Touré.

COVID-19 was declared a pandemic in March 2020. For case management, Mali has created several treatment sites including the site of the CHU Gabriel Touré. AIMS: The objective of the study was to analyse drug prescriptions for the COVID-19 treatment at the CHU Gabriel Touré. METHODS: We performed a retrospective and descriptive study from April to September 2020. Drug prescriptions and hospital records were used to collect data. Prescriptions and hospital records were used to collect data. RESULTS: A total of 29 patients were hospitalized. The median age was 44 years, 75.90% of patients had at least one pathology associated with COVID-19. The number of prescriptions was 333 comprising 870 lines of prescriptions including 33.21% for standard treatments, and 66.79% for associated pathologies. with 86.23% available at the Hospital Pharmacy. Chloroquine, dosed at 250mg, was administered at 500mg twice a day. The national guidelines from the treatment of COVID-19 recommends 200mg of chloroquine in two doses. Vitamin C was prescribed for all patients although not included in the national guidelines. The class of drugs for the blood and blood-forming organs was the most prescribed (31.49%). The average cost of treatments was 65,602 ± 106,858 FCFA with a maximum of 567,860 FCFA. An evaluation of prescriptions in other treatment sites is necessary.

La COVID-19 est une infection virale qui s'est propagé dans tout le monde. Pour la prise en charge des cas, le Mali a créé des sites de traitement dont celui du CHU Gabriel Touré. OBJECTIF: C'était d'analyser les prescriptions médicamenteuses pour le traitement de la COVID-19 au CHU Gabriel Touré. MÉTHODOLOGIE: L'étude était rétrospective et descriptive et a concerné la période d'avril à septembre 2020. Elle s'est déroulée au Centre de Traitement COVID-19 du CHU Gabriel Touré et à la Pharmacie Hospitalière de cet hôpital. Les ordonnances et les registres d'hospitalisation ont servi à collecter les données. RÉSULTATS: Au total, 29 patients ont été hospitalisés. L'âge médian était de 44ans, 75,90% des patients présentaient au moins une pathologie associée à la COVID-19. Le nombre d'ordonnances était de 333 comportant 870 lignes de prescriptions dont 33,21% de traitements standards et 66,79% pour les pathologies associées avec 86,23% disponibles à la Pharmacie Hospitalière. Le phosphate de chloroquine, dosé à 250mg, était administré à 500mg deux fois quotidiennement. Dans les directives nationales le phosphate de chloroquine était à 100mg pour 200mg trois fois quotidienne. La vitamine C non prévue dans les directives a été prescrite à tous les patients. La classe des médicaments du sang et des organes hématopoïétiques a été les plus prescrits (31,49%). Le coût moyen des traitements était de 65602±106858 FCFA avec maximum de 567860 FCFA. Une évaluation des prescriptions dans les autres sites de traitement est nécessaire.

[Epidemiological situation of yellow fever in Burkina Faso from 2003 to 2008]. / Situation épidémiologique de la fièvre jaune au Burkina Faso de 2003 à 2008.

Despite the existence of antiamaril vaccine in the routine Expanded Program of Immunization (EPI) in Burkina Faso, yellow fever cases still occur in the country. In collaboration with WHO, the national health authorities set up a surveillance system through the national reference laboratory in Centre Muraz (Bobo-Dioulasso). All samples of feverish icterus cases of the 63 health districts of the country were analysed in this lab for M Immunoglobulin using Enzyme Linked Immunosorbent Assay (Elisa). Positive Elisa samples were sent to Pasteur Institute of Dakar (Senegal) for confirmation using a Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) assay. From 2003 to 2005, the number of confirmed cases of yellow fever was respectively of 1/413 (0.24%), 14/616 (2.27%) and 19/618 (3.07%). This increasing of the proportion was statistical different. Then, from 2006 to 2008, the confirmed case proportion was respectively 0.35%, 0.27 and 0.54% without significant difference (P = 0.69). The entomological investigations conducted in 2004 in Bobo-Dioulasso showed that the water pots constitute 48.11% mosquitoes lodgings, followed by metal drums with a strong representation of Culex quinquefasciatus (48.7%), followed by Aedes aegypti (43.3%), as vectors in domestic areas with sectorial variations. These results suggest that more attention must be paid by the national health authorities and international community regarding this disease.

[Diagnostic and surgical approach to an hourglass-shaped nasopalatine glioma in an infant]. / Approche diagnostique et chirurgicale d'un gliome naso-palatin "en sablier" chez un nourrisson.

The authors report a case of glioma nasopalatine Multifoil in wallet, location-intra nasal and palatal left. The nasal glioma is a rare congenital malformation presenting as a nasal mass composed of neuroglial tissue heteropias resulting from an abnormality in embryonic development. It is a benign tumor that fits into the nosology of the masses of the midline. This abnormality arises primarily a diagnostic problem because often mistaken for a meningo-encephalocele or a nasal dermoid cyst. Localization nose and palate, an hourglass, is extremely rare if not exceptional; The computed tomography (CT) has enabled the accurate assessment of injury and has guided the choice of surgical technique. The resection was done successfully without recurrence. Histology examination of the surgical specimen confirmed the nature of astrocytic neuroglial tumor. The location of the tumor pedide palate to that of the left nostril is special and especially histological diagnosis of this congenital malformation.

Distribution of insensitive acetylcholinesterase (ace-1R) in Anopheles gambiae s.l. populations from Burkina Faso (West Africa).

OBJECTIVE: To investigate through countrywide sampling at 20 localities across the three different agro-climatic zones of Burkina Faso, the distribution of the acetylcholinesterase insensitive mutation ace-1(R), which confers resistance to organophosphates (OP) and carbamates (CM) insecticides in An. gambiae s.l. METHODS: Adult mosquitoes were collected by indoor aerosol spraying from August to October 2006. Specimens were identified to species by polymerase chain reaction (PCR) assay and characterized for the ace-1(R) mutation using a PCR-restriction fragment length polymorphism diagnostic. RESULTS: Collected mosquitoes were a mixture of An. gambiae s.s. and An. arabiensis across the Sudan (98.3%vs. 1.7%), Sudan-sahelian (78.6%vs. 21.4%) and the Sahel (91.5%vs. 8.5%) ecotypes. The An. gambiae S-form predominated in the Sudan sites from the West (69%vs. 31% for the M form) but was not found in the Sahel (100% M form). The ace-1(R) mutation was dispersed throughout the Sudan and Sudan-sahelian localities at moderate frequency (<50%) but was absent in the Sahel. It was far more prevalent in S form than M form mosquitoes (0.32 for the S form vs. 0.036 for the M form). No An. arabiensis was detected carrying the mutation. The geographic distribution of ace-1(R) in the Sudan and Sudan-sahelian correlated with the cotton growing areas dispersed throughout the two climatic zones. CONCLUSIONS: These results have special significance as OP and CM insecticides have been proposed as alternatives or additions to pyrethroids which are currently used exclusively in many vector control programmes.

Year to year and seasonal variations in vector bionomics and malaria transmission in a humid savannah village in west Burkina Faso.

A longitudinal entomological study was carried out from 1999 to 2001 in Lena, a humid savannah village in the western region of Burkina Faso in order to establish malaria vector bionomics and the dynamics of malaria transmission. In the first year, malaria transmission was mainly due to An. gambiae s.s., but during the two later years was due to An. funestus, which were observed in high frequency towards the end of the rainy season. PCR identification of samples of An. gambiae s.1. showed 93% to be An. gambiae s.s. and 7% An. arabiensis. An. funestus constituting more than 60% of the vectors were identified in PCR as An. funestus s.s. The persistence of intense vectorial activity in this village was probably due to the road building in a swampy area creating a semi-permanent swamp that provided large sites for larval mosquitoes. These swampy sites seemed to be more favorable for An. funestus than for An. gambiae s.s. Thus, land development must be monitored and subjected to planning to minimize vector proliferation. Such a system of planning could lead to the restriction or even elimination of the swamp that is the source of larvae developing in the heart of the village.

Distribution of the members of Anopheles gambiae and pyrethroid knock-down resistance gene (kdr) in Guinea-Bissau, West Africa.

An entomological survey conducted in 2002 in Guinea Bissau aimed i) to study the distribution of the members of Anopheles gambiae Giles complex (Diptera: Culicidae) throughout four ecological areas extended from mangrove to savannah ii) to evaluate the insecticide susceptibility status of these malaria vectors exposed to permethrin 0.75% and DDT4%, and finally iii) to investigate the occurrence and the spread of the Leu-Phe knock down resistance (kdr) gene associated with pyrethroid and DDT resistance within these vector populations. Adult female mosquitoes issued from indoor morning collections were tested using WHO procedures, test kits and impregnated papers to assess their insecticide susceptibility status. Tested specimens were identified by PCR assays and characterized for the kdr gene. Malaria vectors were mainly dominated elsewhere by An. gambiae s.s. (both S and M molecular forms) living in sympatry with low proportion of An. melas in the littoral. An. gambiae s.s. tested populations were fully susceptible both to permethrin 0.75% and to DDT 4% irrespective to their location and ecotypes. The Leu-Phe kdr mutation was detected at low frequency only in two sites respectively urban (Bissau) and Guinea-savannah (Gabu) areas. It occurred only in the S molecular form in Gabu (at the frequency of 0.14) and both in the S and M molecular forms in Bissau at the frequency of 0.06 and 0.02 respectively. These results suggested that the populations of An. gambiae s.s., the most frequent malaria vector in Guinea Bissau, still remain cross-susceptible to pyrethroids and DDT This susceptibility status and the frequency of resistance mechanism such as the kdr mutation must be monitored in the future particularly in the urban and savannah areas with continuous and intensive use of insecticides.

[Epidemioclinical and Therapeutic Study of Condylomas (Genital Warts) in Dermato-Venereology Department (CHU Treichville, Abidjan, Côte d'Ivoire, 2013-2016)]. / Étude épidémioclinique et thérapeutique des condylomes vénériens dans un service de dermatovénéréologie (CHU Treichville, Abidjan, Côte d'Ivoire, 2013-2016).

We have conducted a retrospective study in the dermatology department of the CHU Treichville in Abidjan during 4 years. Three hundred and fifty cases of venereal warts were recorded with a hospital frequency of 1.5%, an average age of 29.37, a female predominance (51.3%), and a sex ratio (M/F) of 0.94. We have observed a giant condyloma in 0.9%, a main localization to the vulva (47.7%) and male genitalia (34.6%); HIV testing carried out in 60.8% of patients was positive in 80.7% of cases, all HIV1. Electrocoagulation was the mean treatment (93.1%), followed by cryotherapy (15 cases), chemotherapy (6 cases), and surgery (3 cases). Recurrences were reported in 9 cases (2.6%) of which more than half has occurred within a month.

Nous avons réalisé une étude rétrospective au sein du service de dermatologie du CHU de Treichville d'Abidjan pendant quatre ans. Trois cent cinquante cas de condylomes vénériens ont été recensés (1,5 % des hospitalisations en dermatologie) ; une moyenne d'âge de 29,37 ans ; une prédominance féminine (51,3 %) et un sexe-ratio (H/F) de 0,94. Nous avons observé un condylome géant dans 0,9 %, une localisation à la vulve (47,7 %) et aux organes génitaux externes masculins (34,6 %). Le dépistage du VIH-1, réalisé dans 60,8 % des cas, s'est avéré positif dans 80,7 % des cas, toujours avec VIH-1. L'électrocoagulation a été le traitement de choix (93,1 %), suivie de la cryothérapie (15 cas), la chimiothérapie (6 cas) et la chirurgie (3 cas). Des récidives ont été relevées dans neuf cas (2,6 %), dont plus de la moitié avant un mois.

Comparative analysis of epicuticular lipid profiles of sympatric and allopatric field populations of Anopheles gambiae s.s. molecular forms and An. arabiensis from Burkina Faso (West Africa).

We analysed by gas chromatography-mass spectrometry (GC-MS) and Gas Chromatography-Flame Ionization Detector (GC-FID) the epicuticular lipid profiles of field females of the major Afro-tropical malaria vector, Anopheles gambiae. The samples were collected in three villages in Burkina Faso (West Africa), where An. gambiae M and S molecular forms and An. arabiensis live sympatrically. The aim was to compare the cuticular hydrocarbon (CHC) composition of individual field specimens of these three taxa, to highlight possible differences among them. All the samples analysed by GC-MS (55 individuals and eight pools) were characterized by the same 48 CHCs and 10 oxygenated compounds. The 19 most abundant CHCs were quantified in 174 specimens by GC-FID: quantitative intra-taxon differences were found between allopatric populations of both An. arabiensis and S-form. Inter-taxa quantitative differences in the relative abundances of some hydrocarbons between pairs of sympatric taxa were also found, which appear to be mainly linked to local situations, with the possible exception of diMeC(35) between An. arabiensis and S-form. Moreover, MeC(29) shows some degree of differentiation between S- and M-form in all three villages. Possible causes of these differences are discussed.

Anopheles funestus (Diptera: Culicidae) in a humid savannah area of western Burkina Faso: bionomics, insecticide resistance status, and role in malaria transmission.

An entomological survey was carried out in three humid savannah sites of western Burkina Faso (Bama, Lena, and Soumousso) to (1) update the taxonomy of the Anopheles funestus Giles group, (2) examine the role of each species in malaria transmission, (3) characterize the insecticide resistance status of this malaria vector, and (4) determine the distribution of An. funestus chromosomal forms in these areas. Polymerase chain reaction identification of the members showed the occurrence of An. leesoni Evans in Lena and An. rivulorum-like in Soumousso in addition to An. funestus s.s. Malaria transmission was ensured mainly by An. funestus s.s. both in Soumousso and Lena and by An. gambiae s.s. Giles in Bama, the rice-growing area. The insecticide resistance status performed only on An. funestus indicated that this mosquito was susceptible to pyrethroids irrespective of the study area, but it was resistant to dieldrin. Furthermore, the occurrence of the two chromosomal forms of An. funestus, namely, Kiribina and Folonzo, seemed to follow ecological setups where Kiribina predominated in the irrigated area and Folonzo was more frequent in classic savannah. This study revealed that the problematic of An. funestus taxonomy was closer to that of An. gambiae requiring more structured studies to understand its genetic ecology.

[Salmonella meningitis in Ouagadougou, Burkina Faso, from 2000 to 2004]. / Méningites dues à Salmonella au CHU de Ouagadougou, Burkina Faso (2000-2004).

56 strains of Salmonella were isolated from the cerebro-spinal fluids (CSF) from meningitis suspected patients at the Yalgado-Ouédraogo University hospital center in Burkina Faso, from January 2000 to December 2004. 75% of the patients were less than 3 years old; 71.4% of the CSF were purulent, with an average of 523 leucocytes/mm3 and 78% of neutrophile polynuclears. The strains identified belonged mostly to Salmonella O: 4.5 group (51.8%). In vitro, 92.7% of the strains were resistant to ampicillin and this resistance was partially restored with amoxicillin/clavulanic acid; however no strain was resistant to ceftriaxone. For the overall 56 patients, 20 different antibiotherapy regimes were used and they were successful in only 27% cases while 71% of patients died and 2% escaped from the hospital. Neurologic sequels were found in a patient treated with both ceftriaxone and chloramphenicol. These results showed that the illness occurred mainly in infants and was associated with high mortality rate. Most of the Salmonella strains were multi-drug resistant. In spite of strains multi-antibiotics resistance, adequate definition of therapeutic lines and early treatment including ceftriaxone could lead to higher cure rates and may improve the outcome.

First biologic and genetic characterization of Toxoplasma gondii isolates from chickens from Africa (Democratic Republic of Congo, Mali, Burkina Faso, and Kenya).

The prevalence of Toxoplasma gondii in free-ranging chickens (Gallus domesticus) is a good indicator of the prevalence of T. gondii oocysts in the soil because chickens feed from the ground. In the present study, prevalence of T. gondii in chickens from Democratic Republic of Congo, Mali, Burkina Faso, and Kenya is reported. The prevalence of T. gondii antibodies in sera of 50 free-range chickens from Congo was 50% based on the modified agglutination test (MAT); antibody titers were 1:5 in 7, 1:10 in 7, 1:20 in 6, 1:40 in 1, and 1:160 or more in 4 chickens. Hearts, pectoral muscles, and brains of 11 chickens with titers of 1:20 or more were bioassayed individually in mice; T. gondii was isolated from 9, from the hearts of 9, brains of 3, and muscles of 3 chickens. Tissues of each of the 14 chickens with titers of 1:5 or 1:10 were pooled and bioassayed in mice; T. gondii was isolated from 1 chicken with a titer of 1:10. Tissues from the remaining 25 seronegative chickens were pooled and fed to 1 T. gondii-free cat. Feces of the cat were examined for oocysts, but none was seen. The results indicate that T. gondii localizes in the hearts more often than in other tissues of naturally infected chickens. Genotyping of these 10 isolates using the SAG2 locus indicated that 8 were isolates were type III, 1 was type II, and 1 was type I. Two isolates (1 type I and 1 type III) were virulent for mice. Toxoplasma gondii was isolated by mouse bioassay from a pool of brains and hearts of 5 of 48 chickens from Mali and 1 of 40 chickens from Burkina Faso; all 6 isolates were avirulent for mice. Genetically, 4 isolates were type III and 2 were type II. Sera were not available from chickens from Mali and Burkina Faso. Toxoplasma gondii antibodies (MAT 100 or more) were found in 4 of 30 chickens from Kenya, and T. gondii was isolated from the brain of 1 of 4 seropositive chickens; this strain was avirulent for mice and was type II. This is the first report on isolation and genotyping of T. gondii from any source from these 4 countries in Africa.

Natural swarming behaviour of the molecular M form of Anopheles gambiae.

In Anopheles gambiae, as in most species of mosquitoes, mating is initiated in flight. The males aggregate in aerial swarms and conspecific females individually fly to these swarms where they mate with males. In this study, we investigated the swarming behaviour of A. gambiae and conducted 2 surveys in the rice field area of the Vallée du Kou in Burkina Faso in 1999 and 2002. A high number of anopheline mosquitoes were observed in this area and both molecular M and S forms of A. gambiae were found in sympatry. Swarms formed a few minutes after sunset in different places and no obvious markers were associated with their occurrence. However, swarms occurred close to cow herds generally in open flat areas, 2-3 m above the ground. Overall, 2829 anopheline mosquitoes were collected from 21 swarms composed primarily of males. A few specimens of Culex quinquefasciatus were collected from 3 swarms. Although both molecular M and S forms were found in sympatry in the village, swarms were composed almost exclusively of the molecular M form. This suggests that there are alternative swarming habits for both molecular M and S forms of A. gambiae in nature.

Wide-scale installation of insecticide-treated curtains confers high levels of protection against malaria transmission in a hyperendemic area of Burkina Faso.

In a region of Sudanese savannah in Burkina Faso, insecticide-treated curtains were installed in 8 out of 16 zones, each covering an area of about 50 km2. Longitudinal entomological monitoring using CDC light traps was performed in 4 villages (2 intervention, 2 control) over a period of 3 years (including 1 year prior to intervention). In the 3rd year a cross-sectional entomological survey using spray catches was performed in 84 villages (40 intervention). Indoor vector densities in protected houses showed large reductions (P = 0.01). The available data were also consistent with an impact on outdoor and unprotected indoor densities. The proportion of mosquitoes carrying sporozoites was 4.1% in protected villages compared with 11.5% in unprotected villages (P = 0.07). Entomological inoculation rates fell substantially (P = 0.01), reflecting these reductions. The impact of this intervention on mosquito survival appears to have been greater than those in similar trials conducted in the Gambia, Ghana and Kenya in which the intervention was applied over smaller areas.