PubMed Health⌕ Search

Biomedical subjects

A Dolo

Publications and source records attributed to A Dolo.

At least 19 recordsLinked to original sources
PubMed2005

Spleen enlargement and genetic diversity of Plasmodium falciparum infection in two ethnic groups with different malaria susceptibility in Mali, West Africa.

The high resistance to malaria in the nomadic Fulani population needs further understanding. The ability to cope with multiclonal Plasmodium falciparum infections was assessed in a cross-sectional survey in the Fulani and the Dogon, their sympatric ethnic group in Mali. The Fulani had lower parasite prevalence and densities and more prominent spleen enlargement. Spleen rates in children aged 2-9 years were 75% in the Fulani and 44% in the Dogon (P<0.001). There was no difference in number of P. falciparum genotypes, defined by merozoite surface protein 2 polymorphism, with mean values of 2.25 and 2.11 (P=0.503) in the Dogon and Fulani, respectively. Spleen rate increased with parasite prevalence, density and number of co-infecting clones in asymptomatic Dogon. Moreover, splenomegaly was increased in individuals with clinical malaria in the Dogon, odds ratio 3.67 (95% CI 1.65-8.15, P=0.003), but not found in the Fulani, 1.36 (95% CI 0.53-3.48, P=0.633). The more susceptible Dogon population thus appear to respond with pronounced spleen enlargement to asymptomatic multiclonal infections and acute disease whereas the Fulani have generally enlarged spleens already functional for protection. The results emphasize the importance of spleen function in protective immunity to the polymorphic malaria parasite.

Adolescent↗
PubMed2005

Distinct interethnic differences in immunoglobulin G class/subclass and immunoglobulin M antibody responses to malaria antigens but not in immunoglobulin G responses to nonmalarial antigens in sympatric tribes living in West Africa.

The well-established relative resistance to malaria observed in the Fulani as compared with other sympatric tribes in West Africa has been attributed to their higher levels of serum immunoglobulin (Ig) G antibodies to malarial antigens. In this study, we confirm and extend the previous findings by analyses of the levels of IgM, IgG and IgG subclasses of anti-malarial antibodies in asymptomatic individuals of different sympatric tribes in Burkina Faso (Fulani/Mossi) and Mali (Fulani/Dogon). The Fulani showed significantly higher median concentrations of anti-malarial IgG and IgM antibodies than the sympatric tribes at both locations. Although the overall subclass pattern of antibodies did not differ between the tribes, with IgG1 and IgG3 as dominant, the Fulani showed consistently significantly higher levels of these subclasses as compared with those of the non-Fulani individuals. No significant differences were seen in the levels of total IgG between the tribes, but the Fulani showed significantly higher levels of total IgM than their neighbours in both countries. While the antibody levels to some nonmalarial antigens showed the same pattern of differences seen for antibody levels to malaria antigens, no significant such differences were seen with antibodies to other nonmalarial antigens. In conclusion, our results show that the Fulani in two different countries show higher levels of anti-malarial antibodies than sympatric tribes, and this appears not to be a reflection of a general hyper-reactivity in the Fulani.

Adolescent↗
PubMed2005

[Intestinal parasitosis during AIDS diarrhoea].

The main goal of this work was to study the parasitic infections during AIDS diarrhoea. A longitudinal study was carried out from October 2000 to November 2001 in the Hepato-Gastro-Enterology department of Gabriel Toure Hospital and in the Department of Epidemiology and Parasitic infections of Faculty of Medicine, Pharmacy and Odonto-stomatology of Bamako (Mali), concerning HIV positive patients suffering from diarrhoea. Detecting microbes in stools has been done through direct microscopic examination and according to procedures of Henricksen Poblenz Baerman, Kato Katz and the PCR. Among the 70 patients involved, the sex-ratio was 53%, the average age was 35 +/- 8.4 years. Fever weight loss, skin affections and digestive mycosis were often associated. Opportunistic infections have been relatively frequent with Cryptosporidium parvum with 20%, Isospora belli with 8.5% and Microsporidium with 11.5% of cases. Other non-opportunistic microbes were found. Death within the first two weeks seems more important in case of infection by Cryptosporidium parvum. The frequency and the danger of those opportunistic infections require their efficient diagnosis and care management.

Acquired Immunodeficiency Syndrome↗
PubMed2003

[Meigs' syndrome. One case].

Meigs' syndrome is a benign tumor of the ovary with recurrent serous effusion which can resorb however after surgery. It is rarely seen. Its physiopathology remains obscure. Presently, our concern is a 34-year-old woman, admitted in an abdominal tension board, seriously affected by dyspnoea and whose state revealed a malignant process. The pelvic abdominal echography and the thoracic radiography have played a prominent role in the diagnostic approach. Ablating the ovarian tumor leads to a quick recovery. The histological nature of this tumor reveals a huge mucinous cystadenoma.

Adult↗
PubMed2003

[Epidemiology of malaria in a village of Sudanese savannah in Mali (Bancoumana). Anti-TRAP and anti-CS humoral immunity response].

Vaccine development research is an important component of malaria control strategies. Thrombospondin related anonymous protein (TRAP) and the circumsporozoite (CS) protein are two antigens of sporozoite surface. Immune response to these two antigens may contribute to the development of anti-sporozoite vaccine. Recent studies suggest that antibodies anti-TRAP may partially block sporozoites penetration in hepatocyte, and thereby reducing malaria morbidity. We carried out a study to assess the seroprevalence of anti-TRAP and anti-CS antibodies and to identify a possible role of these antibodies on malaria morbidity in children 1-9 years old living in a rural hyperendemic village. We performed 5 cross sectional surveys and a longitudinal follow up in 1993 and 1994. During each cross sectional study, children were examined for fever and splenomegaly; all febrile children received thick film examination, and serologic analysis was performed in one third of these, randomly selected. The results show that the seroprevalence of anti-TRAP and anti-CS varied with age and season (p < 0.05). Association between the prevalence of anti-TRAP and splenomegaly was observed during two cross sectional surveys (June and October 1993). The presence of anti-TRAP antibody was associated with Plasmodium falciparum infection at the beginning of the transmission season (June 1993 and July 1994). A negative association between the level of anti-TRAP title and parasitemia was observed (March and October 1994). These findings suggest no clear evidence of the protective role of anti-TRAP antibodies in uncomplicated malaria, possibly due to the limited persistence of these antibodies under natural situations.

Antibodies, Protozoan↗
PubMed2003

[Epidemiology of malaria in a village of Sudanese savannah area in Mali (Bancoumana). 2. Entomo-parasitological and clinical study ].

We carried out five cross sectional surveys between 1993 and 1994 to assess the epidemiology of malaria in the village of Bancoumana, located in the Sudanese savannah areas of Mali. Each survey included a collection of entomological, clinical, parasitological and immunological data. The study population involved 1600 children from six months to 9 years of age. The main vector was Anopheles gambiae s.l., man bite rate and entomological inoculation rate were maximum respectively in August (peak of the transmission season) and October (end of transmission season). Plasmodium. falciparum was the main parasite species observed. Spleen enlargement rate, parasite rate, gametocyte rate and parasite density varied significantly with age and season. The parasite rate, gametocyte rate and parasite density were significantly low in October 1994 compared with October 1993 while the entomologic parameter did not show any variation over the two years. This reduction of parasitologic index between 1993 and 1994 may be related to an increase of anti-malarial drug use in the population. Our results show that malaria is hyperendemic in the village of Bancoumana.

Animals↗
PubMed2002

[Systematic search for parasites among leprosy patients in Mali].

Practice of multidrug therapy in leprosy (combination Dapsone + Rifampicine + Clofazimine) established since 1981, has significantly reduced the incidence of the disease. However, immunosuppression due to treatment of multi-drugs therapy induced adverse reactions with glucocorticoid and the change in host immune response due to the leprosy itself, might increase the risk of parasitic infections. To test this hypothesis, we carried out a case-control study at the "Institut Marchoux" in Bamako. Stool and urine samples from all patients included in the study were examined for parasites identification. In addition, we performed thick and thin blood film to identify malaria infection and skin biopsy (snip) to detect onchocerciasis. A total of 121 cases of leprosy and 219 controls aged 10-84 years old were included in the study from March 1999 to February 2000. Sixty two percent (n = 121) of cases were treated with glucocorticoid. The prevalence of infection due to Entamoeba coli and Entamoeba histolytica were higher in cases than in controls (p = 0.02). The prevalence of infection due to hookworms was higher in cases than in controls. There was no difference of the infections to the other intestinal parasites. Three cases of cryptosporidiosis and one case of isosporosis were observed in leprosy group vs none in the control group. There was no significant difference between cases and controls with regard to prevalence of Schistosoma haematobium, Trichomonas vaginalis and Onchocera volvulus. The prevalence of Plasmodium falciparum was 4.9% (6/121) in the leprosy case and 7.8% (17/219) in the control group. In conclusion, despite the corticotherapy and immunosuppression due to leprosy, there was no difference in prevalence of pathogenic parasites. Entomoeba coli, Entamoeba histolytica which have significantly higher prevalence among the cases were not pathogen therefore there was no higher risk of severe intestinal parasitosis among the cases of leprosy. Treatment with glycocorticoid in patients with leprosy did not suggest any impact on the prevalence of this parasitic infections. In addition, multidrug therapy did not show any effect on the carriage of Plasmodium falciparum.

Adolescent↗
PubMed2000

What does a single determination of malaria parasite density mean? A longitudinal survey in Mali.

Temporal variations of blood parasite density were evaluated in a longitudinal study of young, asymptomatic men in a village with endemic malaria in Mali (West Africa). Our main intention was to challenge the value of a single measure of parasite density for the diagnosis of malaria, and to define the level of endemicity in any given area. Parasitaemia and body temperature were recorded three times a day in the wet season (in 39 subjects on 12 days) and in the dry season (in 41 subjects on 13 days). Two thousand nine hundred and fifty seven blood smears (98.5% of the expected number) were examined for malaria parasites. We often found 100-fold or greater variations in parasite density within a 6-hour period during individual follow-up. All infected subjects had frequent negative smears. Although fever was most likely to occur in subjects with a maximum parasite density exceeding 10000 parasites/mm3 (P = 0.009), there was no clear relationship between the timing of these two events. Examples of individual profiles for parasite density and fever are presented. These variations (probably due to a 'sequestration-release' mechanism, which remains to be elucidated) lead us to expect a substantial impact on measurements of endemicity when only a single sample is taken. In this study, the percentage of infected individuals varied between 28.9% and 57.9% during the dry season and between 27.5% and 70.7% during the wet season. The highest rates were observed at midday, and there were significant differences between days. Thus, high parasite density sometimes associated with fever can no longer be considered as the gold standard in the diagnosis of malaria. Other approaches, such as decision-making processes involving clinical, biological and ecological variables must be developed, especially in highly endemic areas where Plasmodium infection is the rule rather than the exception and the possible causes of fever are numerous.

Adult↗
PubMed1999

Thrombospondin related adhesive protein (TRAP), a potential malaria vaccine candidate.

We have investigated whether naturally induced immunity to Plasmodium falciparum thrombospondin related adhesive protein contributes to protection against malaria in humans. We have carried out a case control study in children living in an endemic region of West Africa to reveal associations between PfTRAP seroprevalence and the risk of cerebral malaria. Sera collected from the case and control groups were analysed by ELISA to compare their serum reactivity against PfTRAP, the circumsporozoite protein and the merozoite surface protein 1. Children with uncomplicated malaria had a significantly higher PfTRAP seroprevalence when compared to children with cerebral malaria. The risk of developing cerebral malaria appeared to depend on the reciprocal relationship between sporozoite inoculation rates and humoral immunity against PfTRAP. Our results suggest that naturally induced humoral immunity against PfTRAP contributes to the development of protection against severe malaria. Experimentally induced immunity against TRAP in different rodent models has consistently proven to elicit a high degree of protection against malaria. This together with the functional properties of TRAP and data describing CD4 and CD8 epitopes for PfTRAP indicate that this molecule could increase the protective efficiency of available sporozoite malaria vaccines.

Africa, Western↗
PubMed1998

Natural polymorphism in the thrombospondin-related adhesive protein of Plasmodium falciparum.

We have developed a typing system using natural sequence variation in the thrombospondin-related adhesive protein (TRAP) gene of Plasmodium falciparum. This method permits a haplotype to be assigned to any particular TRAP gene. We have applied this method to a hospital-based, case control-study in Mali. Previous sequence variation and conservation in TRAP has been confirmed. Particular TRAP haplotypes can be used as geographic hallmarks. Because of the high level of conflict between characters, we have examined the phylogenetic relationships between parasites using a network approach. Having received patient samples from urban and periurban areas of Bamako, the majority of haplotypes were closely related and distinct from TRAP sequences present in other continents. This suggests that the structure of TRAP can only tolerate a limited number of sequence variations to preserve its function but that this is sufficient to allow the parasite to evade the host's immune system until a long-lived immune response can be maintained. It may also reflect host genetics in that certain variants may escape the host immune response more efficiently than others. For vaccine design, sequences from the major regional variants may need to be considered in the production of effective subunit vaccines.

Animals↗
PubMed1998

Gametocyte infectivity by direct mosquito feeds in an area of seasonal malaria transmission: implications for Bancoumana, Mali as a transmission-blocking vaccine site.

Infectivity of gametocytemic volunteers living in Bancoumana, a village 60 km from Bamako, Mali, was determined by direct feeds of laboratory-reared Anopheles gambiae s. l. Gametocytemic adolescents (10-18 years old) were as infectious to mosquitoes as younger volunteers and appear to be a more suitable population for testing transmission-blocking efficacy as compared with adults (> 18 years old). To begin to validate the membrane-feeding assay, sera collected from these same volunteers were subjected to a standard membrane-feeding assay. The data suggest that areas with intense but seasonal transmission might be feasible sites for testing transmission-blocking vaccines because of the high gametocytemic rates, high mosquito infectivity rates, and lack of pre-existing humoral-mediated transmission-blocking activity. The differences observed between field-based direct mosquito feeds and laboratory-based membrane feeding assays suggests that caution be used in interpreting Phase I study results in which laboratory-based membrane-feeding assays are used as a surrogate for vaccine efficacy.

Adolescent↗
PubMed1997

Seasonality, malaria, and impact of prophylaxis in a West African village. II. Effect on birthweight.

The impact of malaria on low birthweight was investigated in Bougoula village (Sikasso region, Mali). In two successive years, pregnant women were followed until delivery. Phase I (1992) was observational, with 135 complete observations. Phase II (1993) included 126 participants, who were offered malaria prophylaxis with proguanil (200 mg/day) and chloroquine (300 mg/week). The results show that 1) infants of first and second pregnancies had lower birth weights (-382.7 +/- 62.6 g; P < 0.0001) compared with higher rank pregnancies; 2) strong seasonal variation in birthweight was observed in Phase I, with an annual cycle, a nadir in January, and an amplitude of 372.4 g (P = 0.0002); 3) parasitemia measured during pregnancy was associated with lower birthweight in infants from first and second pregnancies, but not from higher parity mothers; and 4) malaria prophylaxis taken for 20 weeks or more in Phase II suppressed the seasonal variation of birthweight and the effect of low parity (+423.4 +/- 118.8 g; P = 0.0004). We conclude that malaria in pregnancy has an important negative impact on birthweight in first and second pregnancies. Prophylaxis with proguanil and chloroquine is an effective prophylaxis when taken for 20 weeks or more.

Adult↗
PubMed1996

[Protozoan infections and intestinal helminthiasis among the population of a village in the northern Sudan savannah area of Mali (West Africa)].

A cross sectional survey was carried out on intestinal parasites in a rural village located in a Sudan savannah area of Mali in September 1994. This survey was aimed to describe the prevalence of intestinal protozoa and helminths, and to evaluate the possible epidemiological impact of some sociobehavioural factors. A total of 209 stool specimens were examined with 3 methods: fresh stool examination, Kato thick smear technique and a formalin-ether concentration technique in a closed system. Cryptosporidium was also searched following the Ziehl-Neelsen staining and the immunofluorescence method using monoclonal antibody. Microsporidia were investigated by Trichrome staining technique. The concentration technique, as expected, was the more sensitive method: the protozoan cyst rate and the helminth egg rate were 70.3% and 11%, respectively. The low prevalence of intestinal nematodes, unexpected for this area, could be attributed to the improvement in sanitation (traditional WC present in 73.9% of the families), but also to the repeated treatments of the population against onchocercosis with ivermectin since 1992. We found no cases of isosporosis, cryptosporidiosis and microsporidiosis in our study population, neither significant association between socio-behavioural factors and parasitic infections.

Cross-Sectional Studies↗
PubMed1994

[Differed autologous blood transfusion in the "G" point hospital in Bamako. Prospective study apropos of 40 cases].

With a sample of 40 patients, the authors conducted a prospective case-control study on the feasibility of differed autologous blood transfusion at Point "G" National Hospital in Bamako, Mali. The method has been accepted by all the patients. No clinical nor biological trouble has been reported by the patients themselves. The authors recommend the use of autologous blood transfusion by other hospital units and the development of regulations governing its implementation.

Adult↗
PubMed1991

Epidemiological basis for clinical diagnosis of childhood malaria in endemic zone in West Africa.

It is difficult to distinguish childhood malaria from other common febrile disorders by parasite count alone, because of the wide variation in tolerance of parasitaemia among individuals. We postulated that the proportion of febrile episodes among young children that can be attributed to parasitaemia varies according to simple clinical criteria. We studied 1114 children aged 2-9 years, who attended a dispensary in the Republic of Niger, with a case-control approach; each of 557 febrile children was matched with a non-febrile control by sex, age, ethnic group, and day of presentation. Febrile episodes were classified according to three clinical criteria: the presence of a likely non-malarial cause; the duration (less than 3 or more than 3 days before presentation); and the intensity (below 39 degrees C or 39 degrees C and above). There was no evidence for an association between febrile episodes and parasite count during the dry, low-transmission, season. During the rainy, high-transmission, season, by contrast, there was a highly significant relation (p less than 0.0001) between the likelihood of fever and the parasite count; each clinical criterion strengthened the association. There was no association between parasitaemia and low intensity fevers, with an obvious cause, that started 3 or more days before presentation, even in the rainy season; however, the relative risk of a fever that met all three criteria developing in those with vs those without parasitaemia was 27.5. The proportion of febrile cases attributable to detectable parasitaemia (population attributable risk) ranged from 0 to 0.92. Our results suggest that simple clinical criteria may be valuable in the selection of febrile patients for antimalarial treatment. In this geographic area, high fever of short duration and with no other obvious cause that occurs during the rainy season is most likely to be malaria.

Animals↗
PubMed1991

[Impact of curtains and blankets impregnated with permethrin on the malarial indicators and the number of malarial attacks per child in a village in an area hyperendemic for malaria on the Malian savannah (preliminary results of the first year study)].

From May 1989 to June 1990 an experimental study has been undertaken in two village's malarial hyperendemy of the Malian savannah. This study's objective was to test the effectiveness, on paludometric parameters and the openness of the population to the impregnated curtains and blankets, of permethrin as strategy of controlling malaria. The experimental village (Tiénéguébougou) and the control one (Kambila) are located in the same ecosystem and as at least 3 km any from each other. The impregnated curtains were installed in all the experimental village's houses and all the 216 residents have received impregnated blankets. The entomological, parasitical and clinical parameters were measured monthly from may 1989 to november 1989. The impregnated curtains were accepted by the population. However the impregnated blankets were little successful. Their impact on the entomological parameters is remarkable with a reduction of more than 98% of ma and the rate of entomological inoculation (REI) in the houses. The reduction of parasitical index is much less perceptible. The effect on the parasitical pressure was manifested by a highly significant difference of splenic index between the two villages (lower in the control village). The main vectors belong to complex: A. gambiae s.l. which rate of parity was not affected by the impregnated material. Very efficient against the harmfulness of in house hematophagic insects, the curtains impregnated by pyrethroids are not sufficient for interrupting the transmission of malaria. Actually, the study is continued for 2 years with a best evaluation of the malarial morbidity.

Adolescent↗
PubMed1990

[Apropos of 507 pregnancies and twin deliveries in the district of Bamako].

This report covers study on pregnancy and delivery of 507 sets of twins: pregnancy involving twins accounts for 1.52%. in over 60% of cases, twins are diagnosed during the last 3 months, 34% by the clinic, 38% by echography and 26% by X-ray over 55% of these patients have undergone no prenatal examination over 91% of these patients had normal deliveries: over 8% had caesarean operations over 41% of deliveries were premature perinatal mortality was 150%, that of the second twin (J2) being 3 times higher than that of the first (JI) 25% of the deliveries were accompanied by haemorrhage of which 8 cases resulted in the mother's death.

Cesarean Section↗