Distinct physiological states of Plasmodium falciparum in malaria-infected patients.

Infection with the malaria parasite Plasmodium falciparum leads to widely different clinical conditions in children, ranging from mild flu-like symptoms to coma and death. Despite the immense medical implications, the genetic and molecular basis of this diversity remains largely unknown. Studies of in vitro gene expression have found few transcriptional differences between different parasite strains. Here we present a large study of in vivo expression profiles of parasites derived directly from blood samples from infected patients. The in vivo expression profiles define three distinct transcriptional states. The biological basis of these states can be interpreted by comparison with an extensive compendium of expression data in the yeast Saccharomyces cerevisiae. The three states in vivo closely resemble, first, active growth based on glycolytic metabolism, second, a starvation response accompanied by metabolism of alternative carbon sources, and third, an environmental stress response. The glycolytic state is highly similar to the known profile of the ring stage in vitro, but the other states have not been observed in vitro. The results reveal a previously unknown physiological diversity in the in vivo biology of the malaria parasite, in particular evidence for a functional mitochondrion in the asexual-stage parasite, and indicate in vivo and in vitro studies to determine how this variation may affect disease manifestations and treatment.

[Disseminated histoplasmosis due to Histoplasma capsulatum var. duboisii in Senegal. A case in HIV-infected patient]. / Histoplasmose disséminée àHistoplasma capsulatum var. duboisii au Sénégal. À propos d'un cas chez un patient VIH positif.

INTRODUCTION: Histoplasmosis, a disease due to Histoplasma capsulatum, is an invasive opportunistic fungal infection, endemic in Africa. So, the occurrence of african histoplasmosis associated with HIV infection has been rarely reported despite the high prevalence of both pathogens in this area. We report the first case of disseminated african histoplasmosis in an HIV-infected Senegalese patient. OBSERVATION: A patient, 50-year-old has been admitted for umbilicate, necrotic and disseminated papulonodular lesions with oral infection, fever and reduction of total body mass. HIV1 test was positive, and CD4 count was 4/mm(3). Direct examination of ulcerated lesions shown extracellular, large, doubly contoured yeasts. After culture, we obtain brownish colonies, septate hyphae, echinulated chlamydospores characteristic of Histoplasma. Cutaneous biopsy revealed polymorphous granulomatous infiltrate, giant cells containing numerous large, doubly contoured, thick-wall yeast-bodies characteristic of H. capsulatum var. duboisii. DISCUSSION: The association AIDS and histoplasmosis frequency is probably underestimated because the difficult diagnosis and the ignorance of the medical staff.

[Update on toxoplasmosis prevalence based on serological tests in pregnant women in Dakar, Senegal from 2002 to 2006]. / Evolution de la séroprévalence de la toxoplasmose chez la femme enceinte a Dakar, Sènegal de 2002 a 2006.

The purpose of this study was to update data on toxoplasmosis antibody prevalence based on antenatal surveillance tests in pregnant women in Dakar, Senegal. The study population consisted of 941 pregnant women referred for diagnosis of toxoplasmosis in the Laboratory of Parasitology and Mycology at Le Dantec University Hospital Center from 2002 to 2006. Two tests using the solid-phase immunoenzymatic method were performed on venous blood samples collected at 3 weeks of interval (S1 and S2). This double testing technique was designed to detect increases in IgM and IgG antibody levels in order to confirm diagnosis of toxoplasmosis by ruling out immune response, acquired immunity or nonspecific antibody fixation. Comparison of S1 and S2 results in the 941 patients indicated a prevalence of 7.7% and 0% respectively for IgM+IgG- cases, 23.3% and 24.3% respectively for IgM+IgG-cases, and 11.3% and 10.2% respectively for IgM+IgG+ cases. The overall prevalence of toxoplasmosis antibodies was 34.5%. These data showing a high prevalence of toxoplasmosis among pregnant women in Dakar underscore the need to improve serological screening and follow up.

[Mycetomas diagnosed in Senegal from 2008 to 2010]. / Mycétomes diagnostiqués au Sénégal de 2008 à 2010.

INTRODUCTION: Mycetomas are inflammatory pseudotumours of subcutaneous and possibly osseous soft fabrics, generally polyfistulas with chronic mode of evolution. PATIENTS AND METHODS: This study was carried out at the laboratory of parasitology and mycology of Le Dantec hospital in Dakar, Senegal, including 113 patients, from june 2008 to july 2010. RESULTS: Patients were from different regions in Senegal and in neighborhood countries, referred to the laboratory for mycetoma diagnosis. Among the 250 patients referred, 113 were positives after direct observation and culture corresponding to 45.2% index of infestation. The age range varies between 13 to 73years with an average age of 33.9years. The age bracket ranging between 20-39years is more infected (27.34%), followed by 40-59years (25.2%), 60years and more (4.5%), 30-39years (16.64%), 13-19years (7.2%). The infection sex rate were, male: 79.6% and female: 20.4%. Infection prevalence profession dependant was found mainly in farmers and breeders with respectively: 48.7%, and 42.5%. The foot infestation is most represented with 72.5%, then leg (12.3%), knee (7.1%), scalp (2.7%), hand (1.8%). The other localizations are found with less than 1%: back, thigh, chest and ganglion inguinal. According to mycetoma agents, fungy are represented than mycetomas actinomycosic with respectively 70% and 30%. The species found were: Madurella mycetomatis (53.1%), Actinomadura pelletieri (23%), Leptosphaeria senegalensis (9.7%), Streptomyces somaliensis (2.6%), Actinomadura madurae (2,6%), Pseudallescheria boydii (1.8%), Nocardia spp. (1.8%), Scedosporium apiospermum (0.9%), Fusarium solani (0.9%). We found agents of dermatophytes: Microsporum langeronii (1.8%), and Trichophyton mentagrophytes (0.9%). CONCLUSION: This study confirms that mycetomas are endemic affections in Senegal, where it still remain a real cause of disability among population leaving in rural area.

Erythrocyte invasion profiles are associated with a common invasion ligand polymorphism in Senegalese isolates of Plasmodium falciparum.

Plasmodium falciparum parasites use multiple ligand-receptor interactions to invade human erythrocytes. Variant expression levels of members of the PfRh and PfEBA ligand families are associated with the use of different erythrocyte receptors, defining invasion pathways. Here we analyse a major polymorphism, a large sequence deletion in the PfRh2b ligand, and erythrocyte invasion profiles in uncultured Senegalese isolates. Parasites vary considerably in their use of sialic acid-containing and protease-sensitive erythrocyte receptors for invasion. The erythrocyte selectivity index was not related to invasion pathway usage, while parasite multiplication rate was associated with enhanced use of a trypsin-resistant invasion pathway. PfRh2b protein was expressed in all parasite isolates, although the PfRh2b deletion was present in a subset (approximately 68%). Parasites with the PfRh2b deletion were found to preferentially utilize protease-resistant pathways for erythrocyte invasion. Sialic acid-independent invasion is reduced in parasites with the PfRh2b deletion, but only in isolates derived from blood group O patients. Our results suggest a significant role for PfRh2b sequence polymorphism in discriminating between alternative erythrocyte receptors for invasion and as a possible determinant of virulence.

[Evaluation of serological tests of toxoplasmosis in pregnant women realized at the Laboratory of Parasitology and Mycology of Le Dantec Teaching Hospital in 2002]. / Bilan des examens sérologiques de la toxoplasmose chez la femme enceinte réalisés au Laboratoire de Parasitologie Mycologe du CHU Le Dantec en 2002.

INTRODUCTION: the toxoplasmosis can occur complications during pregnancy as serious repercussions on the foetus with the risks linked to this pathology such as abortion. However these complications can be avoided during the pregnancy by an early diagnosis. The objective of this study is to determine the prevalence of toxoplasmosis during pregnancy. MATERIALS AND METHODS: we undertook this study on 109 pregnant women addressed to the laboratory of parasitology and mycology of the CHU Dantec for toxoplasmosis serological test on 2002. We used a immunoenzymatic technical in solid phase whose principle rests on the change of coloration in the presence of antibody of IgM or IgG; coloration whose intensity is function of the title of antibody. For that, two serological tests (S1 and S2), starting from two venous blood at 3 weeks of interval, are carried out among these pregnant women. This second serology will make it possible to confirm or cancel an evolutionary toxoplasmosis based on the variation of the title in antibody between the first (S1) and the second serology (S2). A control is carried out among these women among whom the diagnosis of the evolutionary toxoplasmosis was established. RESULTS: they show that with the first (S1), from the 109 patients, 3% were positive with the antibodies IgM type, 22% positive with IgG, and 11% positive with IgG and IgM. 36% of the women present a positive diagnostic at the first serology (S1). The second serology (S2) shows that among the 36% of the women diagnosed positive with the first serology, 11% made an evolutionary toxoplasmosis. CONCLUSION: This study shows a rather significant of serological toxoplasmosis discovered fortuitously among pregnant women at the time of their assessment of pregnancy.

Defining the origin of Plasmodium falciparum resistant dhfr isolates in Senegal.

We previously reported a high baseline prevalence of mutations in the dhfr and dhps genes of Plasmodium falciparum throughout Senegal. The highest prevalence of the triple dhfr pyrimethamine associated mutations were found in isolates obtained in the western part of the country near the capital city of Dakar. In this study, we sought out to determine the relatedness of dhfr wild type and mutated strains by analyzing three microsatellite regions upstream of the dhfr locus. Twenty-six of the 31 wild type strains had a unique microsatellite pattern. In contrast, of the 17 isolates containing the triple mutation in dhfr, 11 had an identical microsatellite pattern. Diverse geographical isolates in Senegal containing the triple dhfr mutation have arisen from a limited number of ancestral strains. In addition, we demonstrate that these isolates have shared ancestry with the previously reported triple mutation haplotype found in Tanzania, South Africa, and southeast Asia. This common ancestry may have implications for the malaria control strategy for reducing the spread of sulfadoxine-pyrimethamine resistance in Senegal and elsewhere in Africa.

Fungal interdigital tinea pedis in Dakar (Senegal).

Fungal interdigital tinea pedis (FITP) is the most frequent dermatomycosis in industrial countries. In African tropics, it's a rare motive of consultation and is discovered while complicated. The aims of this article were: to determine the frequency of interdigital tinea pedis among overall mycological analysis in our laboratory; to study epidemiological, clinical and mycological aspects of FITP in outpatients attending the Le Dantec mycology laboratory in Dakar. A total of 62 males (60%) and 42 females (40%), mean age: 43.15 years (range: 11-81 years), were received from January 2011 to December 2015 for suspicion of FITP. Skin specimens were taken from all patients for microscopy and fungal culture. The frequency of ITP represents 5.6% (104/1851) among our overall mycological analysis. FITP was confirmed in 68 patients (SPI=65.38%), mainly located between the 4th and 5th toes and 71 fungal species were isolated (CPI=68.27%). Among patients with confirmed FITP, there were 38 males (56%) and 30 females (44%). The prevalence was highest in patients between 44 and 54 years (26%). Candida albicans, Fusarium solani and Trichophyton interdigitale were shown to be the most common pathogens respectively for yeasts (39%), non-dermatophytic filamentous fungi (NDFF; 21%) and dermatophytes (11%). So FITP isn't a common reason for consultation in Dakar but its simple parasitic index (SPI) is still very high and dermatophytes formerly the main causative agents are being relegated to third place behind yeasts and NDFF.

[In vitro evaluation of the sensitivity of Plasmodium falciparum to chloroquine using the deli-microtest in region of Dakar, Senegal]. / Evaluation de la sensibilité in vitro de Plasmodium falciparum à la chloroquine par le DELI-microtest dans la région de Dakar (Senegal).

This study was carried out between 2000 and 2001 in the peri-urban Pikine area located 15 km from Dakar, Senegal. The purpose was to evaluate the in vitro sensitivity of Plasmodium falciparum isolates to chloroquine, which was the recommended first-line drug for uncomplicated malaria treatment in Senegal. Testing was carried out using the double-site enzyme-linked lactate dehydrogenase imnunosorbent (DELI) microtest. The DELI-microtest is an ELISA method using 2 monoclonal antibodies against 2 antigenic sites of the specific P. falciparum lactate dehydrogenase (LDH) enzyme. The level of LDH is proportional to the extent of parasite growth. P. falciparum isolates were cultured in 96-well plates in RPMI 1640 medium supplemented with hypoxanthine and albumax, in the presence of chloroquine sulphate concentrations ranging from 5.6 nM/L to 2870.8 nM/L. Plates were incubated in a candle-jar for 48 hours at 37 degrees C and frozen at -20 degrees C. The DELI-microtest was performed using the supernatant of hemolysed cultures. The amount of pLDH released was evaluated based on optical density. The chloroquine sensitivity of the isolate was estimated based on IC50 with a cut-off of <100 nM/L. Geometric mean IC50 values were 41 nM/L (range: 4.8 nM/L to 1435 nM/L) and 135 nM/L (range: 8.63 nM/L to 2153 nM/L) in 2000 and 2001 respectively. This study demonstrated a dramatic increase in the in vitro resistance of P. falciparum to chloroquine from 30% in 2000 to 59.6% in 2001. These findings suggest that regular surveillance of in vitro drug resistance is important to predict in vivo drug resistance and allow timely changes in public health recommendations.

[Prevalence of urinary schistosomiasis in the school population in Senegal in 2002]. / Prevalence de la bilharziose urinaire en milieu scolaire au Senegal.

INTRODUCTION: The strong prevalence of schistosomiasis in the school population is correlated with underperformance in educational outcomes in Senegal. The geoclimatic conditions and bad socio-economic conditions facilitate transmission of these infections. This study was to define t he prevalence of these infections in sites throughout the country in school age children. MATERIALS AND METHODS: This study was undertaken from November 2002 to January 2003 and included 63 schools; (n=2245) for an effectif of 30 000 pupils, means 7.4%. These pupils underwent urine examination for schistosomiasis in children with hematuria using millipore filtration method. RESULTS: The results of the study are: overall there were 364 cases (16%). Prevalence rates: Tambacounda 27.8%, Bakel 21.5%, Kédougou 21.8%, Matam 13%, Podor 22.5%, Dagana 28.3%, and Saint-Louis 0%. This study demonstrates a high prevalence of parasites in school age children. Notably there is unique infection patterns in each village and this data will help direct public health interventions. CONCLUSION: These results show a high rate prevalence of urinary schistosomiasis in school population in these departments. It explains the underperformance in educational outcomes in these a reas.

[Tinea pedis due to Fusarium solani in Dakar]. / Intertrigo interorteils à Fusarium solani à Dakar.

A patient presented with intertrigo at the second, third and fourth interdigitals spaces lasting for four years in which Fusarium solani was highlighted. The search for contributing factors revealed a concept of foot washing with water at least five times a day for ablutions, associated with wearing closed shoes all day and the absence of immunosuppression and diabetes. The diagnosis of Fusarium was made on the basis of direct examination and culture. Combined treatment with griseofulvin oral and topical ciclopirox was introduced and allowed healing after 45 days at which an antifungal powder was prescribed for relay. This case adds to the rare cases of intertrigo Fusarium sp. and confirms the frequent practice of ablutions as favoring factor.

[Qualitative fungal composition of services at risk of nosocomial infections at Aristide Le Dantec Hospital (Dakar)]. / Composition qualitative de la flore fongique de l'environnement de 07 services à risque d'infections fongiques au CHU Aristide Le Dantec (Dakar).

INTRODUCTION: In hospitals, the quality control of the air is a key element. Indeed airborne fungi constitute a real danger for patients hospitalized in wards at risk of nosocomial infections especially when they are immunocompromised. OBJECTIVES: The objective was to determine the qualitative fungal flora composition of wards at risk of nosocomial infections at Le Dantec teaching hospital. MATERIALS AND METHODS: Between April and May 2013, 73 samples were collected from 45 compartments within seven services at risk of nosocomial infection at Aristide Le Dantec teaching Hospital (Dakar). Samples were made once by sedimentation method and the percentage of positive cultures was 100%. The most represented species were Cladosporium spp. (91.1%), Aspergillus spp. (86.6%), Penicillium spp. 71.1% and Candida spp. (57.7%). Candida albicans and Aspergillus fumigatus were isolated respectively at 15.5% and 11.1%. Wards have been classified according to the number of species isolated; 11 species in pediatric oncology, 10 species in pediatric surgery/neonatal and intensive care, nine species for oncology, eight species in general surgery and dermatology, and four species in internal medicine. CONCLUSION: This study shows that fungi causing nosocomial infections are present in hospital and their monitoring should be included in the program of Nosocomial Infections Prevention Committees (CLIN).

[Epidemiological profile of Tinea capitis in Dakar (Senegal). A 6-year retrospective study (2008-2013)]. / Profil épidémiologique des teignes du cuir chevelu à Dakar (Sénégal). Bilan d'une étude rétrospective de six ans (2008-2013).

INTRODUCTION: Tinea capitis is considered as a public health problem in Senegal. The aim of this study was to investigate trends in the incidence, the mycological and epidemiological aspects of tinea capitis diagnosed at Le Dantec Hospital in Dakar. METHOD: Our work is a retrospective study concerning all scalp samples taken by the parasitology laboratory, over a 6-year period (2008-2013). RESULTS: A total of 1640 specimens were examined. Of these, 566 were positive with direct examination and after culture. We noted the reduction of patients and of the incidence of tineas during 6 years with variations of 147 (46.82%) to 37 (22.02%). The average incidence of the tineas during six years was 34.51%. Patients' age varied between 1 to 83 years with a mean of 27.33 years. Prevalence varied between age groups, with 10.61 % in adults between 20 to 29 years, 7.19% in children between 0 to 9 years, 6.04% between 10 to 19 years, and 5.91% in adults between 30 to 39 years. Women were more infected 469 (82.9%) than men 97 (17.1%). The main dermatophytes isolated were: T. soudanense in 318 cases (56.18%), T. rubrum in 104 cases (18.37%), M. langeronii in 72 cases (12.72%), M. canis in 36 cases (6.36%), and T. mentagrophytes in 26 cases (4.60%). CONCLUSION: Our study showed a decrease in the annual incidence of tinea capitis over the study period with an evident increase in trichophytic tinea. This study showed that tinea is endemic in Senegal mainly among women between 20 and 29 years.

[Nondermatophytic and noncandidal fungi isolated in Le Dantec University hospital of Dakar in 2014: Epidemiological, clinical and mycological study]. / Champignons non dermatophytiques et non candidosiques isolés au CHU Le Dantec de Dakar en 2014 : étude épidémiologique, clinique et mycologique.

In recent years, the incidence of superficial fungal infections involving nondermatophytic and noncandidal fungi increased considerably. The objective of this work was to analyze the epidemiological, clinical and mycological fungal infections due to nondermatophytic and noncandidal fungi diagnosed in the laboratory of parasitology-mycology of Le Dantec hospital in Dakar. With a retrospective study of the various cases of nondermatophytic and noncandidal fungi isolated in the laboratory of parasitology-mycology during the period of November 2013 to December 2014, we collected 22 cases of infections in 11 men and 11 women; age ranging from 17 to 75 years with a mean of 45.3 years (sex ratio=1): eight cases of intertrigo, seven cases of onychomycosis, four cases of palmoplantar keratoderma (KPP), a case of onychomycosis associated with interdigital intertrigo, a case of infectious myositis and one case of African histoplasmosis. We have isolated and identified a total of 22 nondermatophytic and noncandidal fungi: ten Fusarium, five Trichosporon, two Chrysosporium, two Geotrichum, one Rhodotorula, one Neoscytalidium dimidiatum and one Histoplasma capsulatum var. duboisii. So we are seeing the emergence of nondermatophytic and noncandidal increasingly isolated from superficial and local lesions. These fungi, generally contaminants or commensal, cause a problem regarding their direct involvement in pathological processes in which they are isolated. So we should respect the recommendations proposed for their involvement in pathological processes and, by a collaboration between clinician and biologist, demonstrate their real involvement through effective, targeted treatment.

[Keratomycosis due to Fusarium oxysporum treated with the combination povidone iodine eye drops and oral fluconazole]. / Kératomycose à Fusarium oxysporum traitée par l'association de la povidone iodée en collyre et du fluconazole per os.

In developing countries where systemic antifungal are often unavailable, treatment of filamentous fungi infection as Fusarium is sometimes very difficult to treat. We report the case of a keratomycosis due to Fusarium oxysporum treated by povidone iodine eye drops and oral fluconazole. The diagnosis of abscess in the cornea was retained after ophthalmological examination for a 28-year-old man with no previous ophthalmological disease, addressed to the Ophthalmological clinic at the University Hospital Le Dantec in Dakar for a left painful red eye with decreased visual acuity lasting for 15 days. The patient did not receive any foreign body into the eye. Samples by corneal scraping were made for microbiological analysis and the patient was hospitalized and treated with a reinforced eye drops based treatment (ceftriaxone+gentamicin). The mycological diagnosis revealed the presence of a mold: F. oxysporum, which motivated the replacement of the initial treatment by eye drops containing iodized povidone solution at 1% because of the amphotericin B unavailability. Due to the threat of visual loss, oral fluconazole was added to the local treatment with eye drops povidone iodine. The outcome was favorable with a healing abscess and visual acuity amounted to 1/200th. Furthermore, we noted sequels such as pannus and pillowcase. The vulgarization of efficient topical antifungal in developing countries would be necessary to optimize fungal infection treatment.

Therapeutic evaluation of two different dose regimens of praziquantel in a recent Schistosoma mansoni focus in Northern Senegal.

A therapeutic trial, involving 130 Schistosoma mansoni-infected children, with no previous history of antischistosomal treatment, was carried out to evaluate the efficacy of two different dose regimens of praziquantel. The study was carried out because low cure rates were described in this recently established (1990) S. mansoni focus in northern Senegal, following treatment with a standard dosage of 40 mg/kg. The subjects were randomly allocated into two groups: one group (1) received 40 mg/kg in one oral dose, the other group (2) was treated with two oral doses of 30 mg/kg at a 6-hr interval. Parasitologic examination and circulating anodic antigen (CAA) detection were performed before, 10 days, three, six, and 21 weeks after chemotherapy. No significant differences in cure rates were found between the two groups. Six weeks after treatment, 34% and 44% of the individuals were found to be stool negative in group 1 and group 2, respectively. However, only 10-15% became completely negative according to the serum CAA antigen assay. Mean egg counts were reduced by 99% in both groups. Antigen detection confirmed the parasitologic results. Fewer side effects were observed in the group treated with 2 x 30 mg/kg, which may be explained by split dosage administration. Our study shows that the low cure rates observed in this area could not be improved by using a higher dosage of praziquantel.

[Comparative efficacy of the use of CDC light traps and humans to sampling anopheles populations. Results obtained in the area of Bignona (Senegal)]. / Efficacité comparée de l'utilisation des pièges lumineux du type CDC et des sujets humains pour l'échantillonnage des populations anophéliennes. Résultats obtenus dans la zone de Bignona (Sénégal).

The simultaneous use for the purpose of comparison of human bait catch and light trap collection for sampling anopheles populations specially the Anopheles gambiae s.l. in the area of Bignona, Senegal shows that: light traps provide more information on the specific composition of anopheles fauna; the performance of light traps and that of human baits are comparable indoor during the period of high density of anopheles. Outdoor, light traps catch fourth less females A. gambiae. But the two methods always vary in the same pattern and identically reflect the density variations of the populations; there is no significant difference between the repletion status, the physiological age and the sporozoite index of females A. gambiae s.l. collected with each of the 2 methods. Light trap collection may therefore be considered a reliable sampling method for A. gambiae s.l. specially inside houses in some areas where this method can efficiently permit to complete the human bait catch for a malaria transmission study.

[Malaria in the southern sanitary district of Dakar (Senegal). 2. Entomologic data]. / Le paludisme dans le District sanitaire sud de Dakar (Sénégal). 2. Données entomologiques.

To complete a parasitological survey, entomological prospections were carried out in the southern sanitary District of Dakar, the most urbanized of the city and which includes the city centre and the oldest administrative districts. The prospections took place between June 1994 and May 1995 in sites 1.5 km apart, and distributed in such a manner that they covered the entire area. On a monthly basis, female Culicidae were collected in each site at night on human volunteers, followed the next day by the collection of early morning residual fauna in 10 bedrooms located in district concessions. For a total of 308 collections at night on human volunteers and from 1,510 rooms for the residual fauna, 22,901 female Culicidae were caught of which 167 anopheles, corresponding to 0.7%, the remaining 98.5% being Culex quinquefasciatus. This was the species that thus explained the mosquito-nuisance of which the inhabitants of the southern District complained during the period of survey. The female anopheles collected belonged to 2 species, An. arabiensis for 97.6% of those caught and An. pharoensis for 2.4%. An. arabiensis were very slightly represented in the southern District with a density of aggressive females of 0.26 bite/man/night (B/M/N) and a density per room of 0.05 female. The aggressive populations appeared to be relatively important only at the end of the rainy season (September-October) with an average of 0.65 B/M/N in sites located at the periphery of the district with a maximum of 1.33 B/M/N. The highest density of endophilic females registered at the end of the rainy season was 0.1 and its highest value in a given site was 0.36 female/room. The parturity rate of aggressive females was 43.5% and those collected in houses of 84% with an anthropophilic index of 0.98. None of the dissected An. arabiensis females (77.3% of those collected) was a carrier of Plasmodium sporozoites and the circum-sporozoite antigen was not found. A very weak density of An. arabiensis and absence of plasmodial infection among dissected females favoured the absence of malarial transmission in the southern District for the period considered. However malaria transmission could not be absolutely ruled out given the presence of hematozoa carriers, as was revealed by the longitudinal follow-up of a cohort carried out concurrently with the entomological prospections of whom some were residents having declared permanent residence in the city for over two years. This entomological data explain the results of the afore mentioned parasitological survey which, with a registered plasmodic index of 0.3%, means that the southern District can be considered as non endemic. The area is however exposed to the risk of epidemic malaria following an important proliferation of anopheles, which is always possible after heavy rains and flooding and/or an important immigration of persons coming from regions of high malarial endemicity.

[Impact of antimalarial drug accessibility on malarial morbidity and chloroquine resistance. A study carried out in Touba (Senegal)]. / Impact de l'accessibilité aux antipaludéens sur la morbidité palustre et la chloroquinorésistance. Etude menée à Touba (Sénégal).

In Touba, more important accessibility to antimalarial drugs and their uncontrolled use let to assure that the rate of malarial morbidity would be lower there than in other place in Senegal whereas the rate of chloroquine resistance would be higher. A checking survey of these assumptions has been carried out from october 15 to november 10, 1995 in Touba's health center. Among 227 feverish subjects investigated, 111 were Plasmodium falciparum carriers. Malarial bouts accounted for 48.9% of the feverish fits observed and for the major cause of consultation during the rainy season. These figures are higher than those usually observed in urban environment. Conversely, the rate of chloroquine resistance is lower than those observed in urban zones, since the therapeutic efficacy of chloroquine on Plasmodium falciparum was 100% in that survey.

[Malaria in the southern sanitary district of Dakar (Senegal). 1. Parasitemia and malarial attacks]. / Le paludisme dans le District sanitaire sud de Dakar (Sénégal). 1. Parasitémie et accès paludéens.

A survey of endemic malaria in Dakar was carried out in the southern sanitary district covering the city centre and neighbouring areas. The survey was scheduled from June 1994 to May 1995 in 12 sites distant from each other by 1000 to 1500 meters. Clinical and parasitological data were collected during weekly medical follow-ups at the patients' home with the systematic research of Plasmodium once a month. The study included 2,337 persons aged between 1 month and 88 years and belonging to 284 volunteer resident families. Through monthly parasitological examinations, a parasite rate (P.R.) of 0.3% and a gametocyte rate (G.R.) of 0.005% were recorded. Only Plasmodium falciparum was observed. The P.R. varied according to age: from 0.1% in the children under 2 years to 0.7% in the young adults (15-20 years) who appeared significantly more affected than the other age groups, including that of children from 2 to 9 years, of whom only 0.3% were infected by the parasite. The P.R. varied also according to the site surveyed: from 0% in the city centre to 1.3% at the periphery of the sanitary district and according to the time of year, reaching its height of 0.8%, between October and December, that is just after the rainy season. At the end of the year of survey, 929 among those surveyed were considered to have been satisfactorily followed. Their annual incidence rate was 2.4% for the parasitemia and of 1.5% for the malaria attacks. None of the participants aged under 2 years had the parasite. Among the others, the annual incidence rate varied according to the age--although not significantly--passing from 1.1% to 5.3% for parasitemia and from 0.4% to 3.0% for malaria attacks. Theses rates did not differ significantly according to site; the cases registered varied between 1% and 8% for parasitemia and 1% and 5.8% for malaria attacks. Only 10.6% of febrile subjects suffered from malaria attacks, but this rate seemed to go up between October to December, rising to 26.6% which corresponds to 1 case of malaria attacks for 4 cases of hyperthermia in that period. Weak density of Anopheline population and satisfactory medical surveillance explain the recorded results.