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O Ndir

Publications and source records attributed to O Ndir.

At least 19 recordsLinked to original sources
PubMed2006

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.

Animals↗
PubMed2005

Mutations in Plasmodium falciparum dihydrofolate reductase and dihydropteroate synthase genes in Senegal.

Senegal recently (2004) switched to sulfadoxine-pyrimethamine (SP) with amodiaquine as first line therapy for malaria in response to increasing chloroquine resistance. In anticipation of emerging resistance to SP as a result of this change in drug pressure, we set out to define the baseline prevalence of SP-associated mutations in the dhfr and dhps genes in Plasmodium falciparum using geographically diverse and longitudinally collected samples. A total of 153 blood samples were analysed from patients (5 years or older) with mild malaria after informed consent was obtained. Longitudinal samples were collected between 2000 and 2003 in Pikine, a suburb of Dakar. Geographically diverse site sampling was carried out in 2003. The mutation prevalence in DHFR codons 51, 59 and 108 is 65%, 61% and 78% in Pikine, 2003. The overall prevalence of the triple mutation that is associated with high-level pyrimethamine resistance is 61%. The mutation prevalence rate in DHPS codons 436 and 437 is 21% and 40%, respectively. There is significant geographic variation in genotypic resistance, as samples from Pikine in 2003 had higher mutation prevalence in the pfdhfr and pfdhps genes compared to samples from Tambacounda (P < 0.015). In summary, this study demonstrates a high background prevalence of SP resistance mutations already present in P. falciparum in Senegal.

Animals↗
PubMed2005

[In vitro evaluation of the sensitivity of Plasmodium falciparum to chloroquine using the deli-microtest in region of 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.

Animals↗
PubMed2004

[Seroprevalence of toxoplasmosis among women having spontaneous abortion and pregnant women following in a center of health up-town in Dakar].

A prospective survey carried on 70 women having a spontaneous abortion and 70 pregnant women was achieved in the center of health Roi Baudouin of Guediawaye (Senegal) between November 2001 to April 2002 to study the toxoplasmosis in the two groups. Anti-toxoplasmosis antibodies were searched for on all women by a technical solid-phase enzyme immunoassay. The solid-phase is a combs. The seroprevalence of the toxoplasmosis is 37.1% among women having aborted and 40% for pregnant women. The difference is not statistically significant (p = 0.729). The seroconversion is 22.8% among women having aborted and 10% for pregnant women. The difference is statistically significant (p = 0.041). The research of factors favoring the infestation, related to through food habits, pleads in favor of a contamination during childhood, essentially soil and/or eating undone meat. With regard the high percentage of not immunized women (62.9% for women having aborted and 60% for pregnant women), it is necessary to take prophylactic measures to prevent congenital toxoplasmosis.

Abortion, Spontaneous↗
PubMed2003

Prevalence of Plasmodium falciparum pfcrt polymorphisms and in vitro chloroquine sensitivity in Senegal.

Mutations in pfcrt K76T are associated with chloroquine resistance in Plasmodium falciparum. Previous studies of K76T mutations in Senegal reported the association of T76 with in vitro-resistant isolates, but this mutation was also prevalent in chloroquine-sensitive isolates. This suggests involvement of additional genetic loci in modulating chloroquine resistance. Additional pfcrt polymorphisms at codons A220S, Q271E, N326S and R371I have been found in chloroquine-resistant isolates. We wanted to test if sequential acquisition of mutations at these codons leads to in vitro chloroquine resistance. Stepwise accumulation of mutations was not detected, rather there was almost complete linkage between the pfcrt K76T mutation and polymorphisms in these codons. Therefore these additional polymorphisms do not enhance the correlation between pfcrt T76 and chloroquine resistance in Senegal. These data suggest that in vitro chloroquine resistance requires the genetic background of the pfcrt K76T mutation and additional mutations in genetic loci outside the pfcrt gene.

Adolescent↗
PubMed2003

[Parasitic risks (bilharziosis and intestinal parasitosis) to Mboune's valley revitalisation (Senegal)].

In order to assess the parasitic risks related to M'Boune's valley water launching, a study has been carried out from September 16 to November 24, 1998 in 12 villages: four villages surrounding the Guiers lake, four villages surrounding Ferlo already water launched 10 years ago, and four villages within M'Boune not water launched. The prevalence rate of urinary bilharziosis is 0.002% in the frist area, 1.3% in the second one and 13.7% in the third area. In these areas, intestinal parasitosis are prevaling respectively at rates of 38.2%, 36.4% and 21.3%. Although, there is no reason to fear immediately a worsening of the epidemiological situation due to M'Boune's valley revitalisation project, nevertheless, appropriate steps should be taken right now aiming at tackling the extension of conditions related to hydric medium.

Adolescent↗
PubMed2002

[Prevalence of intestinal parasitis at the King Baudouin health center of Guediawaye (Senegal)].

A prospective study carrying on 302 samples of stools of aged children of 0 to 15 years has been achieved between January 02 and April 11 2001 in the center of health Roi Baudouin of Guediawaye (SENEGAL) to appreciate the prevalence of intestinal parasitis. For every child, we made a scotch test, a macroscopic exam of stools and a microscopic exam to the direct analysis and after concentration by the method of RITCHIE simplified. The global prevalence is 56,62%. Ascaris lumbricoides arrived in head with 34,17%, follow-up of Giardia lamblia (22,50%), Trichirus trichiura (22,08%) and Amoeba (14,58%). The prevalence varied with age and the children who are 11 to 15 years have the indication of infestation the most elevated (75,86%): The difference of prevalence to the sex and according to the presence or no current water is not meaningful. On the other hand topics to weak standard of living have an indication elevated parasitis with 66,05%. So measures of efficient struggle must be undertaken to combat these intestinal parasitis.

Adolescent↗
PubMed2002

[Two unexpected cases of hepatobiliary fascioliasis in Dakar (Senegal)].

The authors report two hepatobiliary distomatosis cases on patients living in Senegal and Cape Verde islands. No similar case has been reported in Senegal so far. The first case was a 41 years old woman who presented enlarged, painful liver with hypereosinophilia. There was no fever. Ultrasound and CT Scan demonstrated the presence of three poorly limited and heterogeneous masses, located on the liver right lobe. The percutaneous biopsy was not suggestive. Because of the fear ofhepatocellular carcinoma, a hepatectomy was performed and eosinophilic abcesses were found in the piece of resected liver with Fasciola eggs. The second case was a 32 years old man who presented a febrile enlarged liver with hypereosinophilia. Ultrasound revealed an heterogenous process of the liver fourth segment Serology study using Fasciola hepatica antigen was positive. The treatment with Praziquantel was successful. The clinical and epidemiological inquiry in both cases has found stays in Cape Verde islands before the disease. This was consistent with a contamination in that region. In both cases either F hepatica or F gigantica could be responsible since the serological tests are not able to differentiate these two species. Parasitic hepatopathies should be recognised particularly when a painful liver process is associated to hypereosinophilia. The serological tests will help to establish the diagnosis

Adult↗
PubMed2001

[Antifungal drug susceptibility of Candida causing oropharyngeal candidiasis in HIV infected patients].

Candidiasis are very usual infections of HIV infected patients. By medicine pressure, susceptibility to antifungal drugs decrease in some Candida strains. This study carded out in 1997 at hospital, aimed to identify the yeast species isolated from HIV infected patients with oropharyngeal candidiasis, test their susceptibility to antifungal drugs and a previous antifungal treatment impact. Thus, 60 patients yielded to questionnary were recruited. Isolated yeast colonies from buccal tract after culture on Sabouraud medium with chloramphenicol were identified with the API 20 C AUX (BioMérieux) system by assimilation of different sugars. Susceptibility was evaluated by ATB FUNGUS (BioMérieux) system. 55 from the 60 isolated yeasts were identified and among them C. albicans and C. tropicalis were the main species with 75% and 11,7% respectively rates. In HIV1 infected patients, all specieswere isolated and C. albicans predominated (80,4%) on the other hand, C. albicans and C. tropicalis were the only isolated yeasts from the HIV2 infected patients with 83,3% and 16,6% respectively rates. Susceptibility of C. albicans was 72,2% to nystatine, 58,3% to amphotericin B, 83,3% to flucytosin, 12,8% to miconazole, 8,5% to econazole and 10,6% to ketoconazole. Susceptibility of C. albicans to polyenes was modified by a previous antifungal treatment. This study indicated emergence of saprophytic yeasts of the buccal mucosa and seemed to be more fostered by HIV1 serotype than HIV2. So, C. albicans's susceptibility to polyenes decreased by untimely use of antifungal drugs and by controlling it one could improve the clinic conditions of HIV infected patients.

Adult↗
PubMed1999

[Deep onchocerciasis of the left thigh. An unusual case].

INTRODUCTION: Commonly onchocercoma has been presented as superficial and multiple nodules. When it's unique and deeply situated, its clinical diagnosis is difficult. An uncommon form of onchocercoma is reported. CASE REPORT: A 37 years old man presented a big tumor at the inferior third of the left thigh like lipoma or liposarcoma because of microcalcifications. The tumor was removed. It was a cyst containing a liquid like an "mango juice". The histological examination was performed. Degenerated microfilariae of Onchocerca volvulus was found. DISCUSSION: A big and deep onchocerma of the thigh is uncommon and diagnosis before operation is very difficult. Histological examination have eliminate filarial infections like Dracunculus medinensis and have given the right diagnosis. Radiological microcalcifications and absence of microfilariae at the parasilogical and ophthalmological examinations recall an "aged" onchocercoma. For this reason, we didn't realise a chemotherapy. CONCLUSION: This tumor in Sahel areas is very difficult to diagnose before operation. The histological examination is very important in this case. We don't use chemotherapy because this onchocercoma looks old without alive microfilariae.

Adult↗
PubMed1999

[Pneumocystosis in HIV infected patients presenting with acid-fast bacilli negative pneumopathy at the Central University Hospital at Dakar].

Pneumocystosis is an opportunist parasitic disease which occurs currently at Europe and United States in HIV infected patients. In Africa, the disease is not current. Pneumocystosis has been detected in the Fann medical universitary center at Dakar from HIV infected patients with acido alcoholo resistant bacilli negative pneumopathy. Analysis of broncho alveolar liquid(BAL) of 29 patients after Giemsa and Blue of Toluidin O staining allowed isolating of two cases of pneumocystosis. A man and a woman were the patients. They were HIV1 positive with at X ray bilateral interstitial syndrome. The CD4 lymphocytes count of the one was lower than 200/mm3 and for the other it was higher than 200/mm3.

Acquired Immunodeficiency Syndrome↗
PubMed1998

[Malaria in the southern sanitary district of Dakar (Senegal). 1. Parasitemia and malarial attacks].

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.

Adolescent↗
PubMed1998

[Malaria in the southern sanitary district of Dakar (Senegal). 2. Entomologic data].

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.

Animals↗
PubMed1997

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.

Adolescent↗
PubMed1997

[Impact of antimalarial drug accessibility on malarial morbidity and chloroquine resistance. A study carried out in Touba (Senegal)].

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.

Adolescent↗
PubMed1997

[Malaria in an urban environment: the case of the city of Rufisque in Senegal].

From April to November 1994, we carried out a study in Rufisque, an urban area located in Dakar Region. During dry season, 5.32% of febrile outpatients were infected with Plasmodium falciparum with a mean parasitic density evaluated at 12,471 p/microliter. One case of cerebral malaria was noted. During raining season, malaria represented 58.75% of the fevers. Ten presented neurological signs; the mean parasitic density was high, 131,140 p/microliter. Two children died. Good efficiency of quinine was noted but chloroquine treatment failures was present: 50%. Generally malaria is less prevalent in urban areas. But in Rufisque ecological conditions are main factors which permit spreading of the disease. Prior measures of control such correct treatment of cases and good management of environment must be done.

Adolescent↗
PubMed1997

[Prevalence of malaria in Dakar, Senegal. Results of serological survey of pregnant and non-pregnant women].

The study of malarial seroprevalence in Dakar has interested 598 women among whom 377 pregnant and 221 non pregnant, between 15 to 45 years old and happens during the dry season, period of which malaria transmission is practically stopped in the locality. Among the tested serums by indirect immunofluorescence with Plasmodium falciparum asexual blood forms as antigen, 24.4% contained antimalarial antibodies. The serological index does'nt vary significantly according to the months during the dry season, the women age and their previous pregnancy number. On the contrary, the women who live in Dakar since less than 2 years, have e higher seropositivity rate of 33.7% than those who are there since more than 2 years, 20.0%. It is likewise for the women practicing chemoprophylaxy with chloroquine of whom 16.5% have antibodies against 26.0% among those who don't practice it. The seropositivity rate doesn't vary significantly according as the women are pregnant (24.7% of positive) or not pregnant (24.0% of positive). The weakness of the serological rate in the examined women, can be explained by the situation of Dakar in a weak malarial hypoendemic area. II shows that the major examined subjects have lost or have never had contact with Plasmodium what predispose them to make severe and complicated malarial attacks.

Adolescent↗