Publications Internationales (Articles Scientifiques)

Résumé / Abstract : Human milk contains a large number of compounds to provide nutrition and defense for the newborn. Among these, oligosaccharides are present in concentrations up to 12 g/L, and their composition varies during lactation. Colostrum from 53 Burkinabe women were collected at the maternity department of St Camille Medical Centre in Ouagadougou (Burkina Faso, West Africa). Colostrum from 50 Italian women were collected at the maternity department of St Bambino Hospital in Catania (Catania, East Sicily, Italy). All mothers spontaneously delivered at term. Italian mothers received an injection of the ergot derivative ergotamine after delivery. Ergotamine, notoriously, delays breastfeeding initiation up to 2 to 3 days. Chromatographic separation of colostrum from both Burkinabe and Italian women showed a progressive appearance of oligosaccharides in the first 3 days. Burkinabe women showed high concentrations of 2-fucosyllactose and lower concentrations of lacto-N-fucopentaose I. By contrast, Italian women showed inverted behaviour. A comparable percentage of the secretor genotype for the Lewis blood group phenotype in both Burkinabe and Italian women was found. According to the different ethnicity, different milk oligosaccharide profiles were documented in the present study. 2-Fucosyllactose in milk should be biologically significant for Burkinabe infants because of the high levels found in their mothers' colostrum after the second day of lactation.

Résumé / Abstract : The aim of our study was to estimate the prevalence of Hepatitis C virus (HCV) among pregnant women and the rate of mother-child transmission. Over one month (April 26 to May 25, 2002) blood samples of 200 pregnant women who gave birth at the maternity of the university hospital and Gounguin center medical of Ouagadougou were tested for anti-HVC antibodies (Ac HCV) and anti HIV antibodies (Ac HIV). Infants born to mother tested positive for Ac HCV and their mother were tested for HCV-RNA. The prevalence of HCV (positive Ac HCV and HCV-RNA) was 2% in pregnant women (4/200). One case of mother-child transmission was found. The virus transmitted was 2a (A/C) genotype. The mother had a high titre of HCV-ARN, was co-infected by HIV and had had history of blood transfusion, excision and tattoo of the gums.

Résumé / Abstract : Toxoplasma gondii (T. gondii) infections can cause serious complications in HIV-infected pregnant women, leading to miscarriage, stillbirth, birth defects (e.g., mental retardation, blindness, epilepsy etc.) and could favor or enhance the mother-to-child transmission of HCV, HBV, and HIV vertical transmission. From May 20, 2004 to August 3, 2005, 336 18-45 years aged pregnant women, were enrolled for an investigation of the prevalence of serum antibodies against T. gondii, HCV, HBV, and HIV using ELISA. The prevalence of T. gondii, HCV, and HBV in pregnant women was 25.3%, 5.4%, and 9.8%, respectively and the HIV serostatus (61.6%) seems to be associated with greater prevalence rates of both T. gondii (28.5% vs. 20.2%) and HBV (11.6% vs. 7.0%). Without taking into account HIV, only 65.5% (220 of 336) of the women were not infected with these agents. The co-infection rate between HIV-infected and -negative women was different statistically: T. gondii/HBV 0.048 versus 0.015, T. gondii/HCV 0.014 versus 0.008, and HCV/HBV 0.005 versus 0.008, respectively. The elevated co-infection rate in HIV-positive women demonstrated that they are exposed to T. gondii, HCV, and HBV infections prevalently by sexual contact.

Résumé / Abstract : Two thirds of the people who have been infected by human immunodeficiency virus (HIV) in the world live in Sub-Saharan African countries. The results of a study measuring the degree distribution of the network of sexual contacts in Burkina Faso are described. Such a network is responsible for the spread of sexually transmitted diseases, and in particular of HIV. It has been found that the number of different sexual partners reported by males is a power law distribution with an exponent gamma = 2.9 (0.1). This is consistent with the degree distribution of scale-free networks. On the other hand, the females can be divided into two groups: the prostitutes with an average of 400 different partners per year, and females with a stable partner, having a rapidly decreasing degree distribution. Such a result may have important implications on the control of sexually transmitted diseases and in particular of HIV. Since scale-free networks have no epidemic threshold, a campaign based on prevention and anti-viral treatment of few highly connected nodes can be more successful than any policy based on enlarged but random distribution of the available anti-viral treatments.

Résumé / Abstract : To identify factors predicting uptake of voluntary HIV counselling and testing in pregnant women.

All pregnant women receiving ante-natal group health education at St Camille Medical Center, Ouagadougou, Burkina Faso from 1 May 2002 to 30 April 2004 were offered voluntary HIV counselling and testing. If they consented, the women were pre-test counselled, tested by two rapid tests giving immediate results and post-test counselled.

Less than one-fifth of pregnant women [1,216/6,639 (18.3%, CI 17.4-19.3%)] accepted voluntary HIV counselling and testing, mainly at the first ante-natal visit (83.4%) and at early gestational age (73.4% before week 24). The HIV seroprevalence rate was 10.6% (8.8-12.5%). The uptake rate was independently associated with age, the number of previous pregnancies and the number of previous miscarriages.

Our two-step approach of group education followed by voluntary HIV counselling and testing yielded a low uptake rate in this setting. However, the drop-out rate after enrolling in the programme was nearly zero. The timing of programme uptake would permit implementation of earlier prophylactic courses. Effective scaling-up of voluntary HIV counselling and testing outside the clinical trial requires a mass sensibilization campaign pointing out the programme's benefits and addressing the stigma of HIV. The independent value of age and previous obstetrical episodes show how important social factors are in influencing the voluntary HIV counselling and testing uptake rate.

Résumé / Abstract : Malnutrition constitutes a public health problem throughout the world and particularly in developing countries.

The objective of the study is to assess the impact of an elementary integrator composed of Spiruline (Spirulina platensis) and Misola (millet, soja, peanut) produced at the Centre Medical St Camille (CMSC) of Ouagadougou, Burkina Faso, on the nutritional status of undernourished children.

550 undernourished children of less than 5 years old were enrolled in this study, 455 showed severe marasma, 57 marasma of medium severity and 38 kwashiorkor plus marasma. We divided the children randomly into four groups: 170 were given Misola (731 +/- 7 kcal/day), 170 were given Spiruline plus traditional meals (748 +/- 6 kcal/day), 170 were given Spiruline plus Misola (767 +/- 5 kcal/day). Forty children received only traditional meals (722 +/- 8 kcal/day) and functioned as the control group. The duration of this study was eight weeks.

Anthropometrics and haematological parameters allowed us to appreciate both the nutritional and biological evolution of these children. The rehabilitation with Spiruline plus Misola (this association gave an energy intake of 767 +/- 5 kcal/day with a protein assumption of 33.3 +/- 1.2 g a day), both greater than Misola or Spiruline alone, seems to correct weight loss more quickly.

Our results indicate that Misola, Spiruline plus traditional meals or Spiruline plus Misola are all a good food supplement for undernourished children, but the rehabilitation by Spiruline plus Misola seems synergically favour the nutrition rehabilitation better than the simple addition of protein and energy intake.

Résumé / Abstract : One thousand three hundred and twenty-eight pregnant women with less than 32 weeks of amenorrhea received voluntary counseling and testing at Saint Camille Medical Center from May 1, 2002 to December 30, 2004. Following informed consent and pre-test counseling, HIV screening was performed in 1,202 women. According to the prevention protocol, HIV-positive women received a single dose of Nevirapine (200 mg) during their labor, while their newborn received a single dose of Nevirapine (2 mg/kg) within 72 hr from birth. HIV seroprevalence (11.2%) was higher than in the overall population. One hundred and ninety-three children were born at the end of December 2004; 53 children (27.5%) followed a short breastfeeding protocol for 4 months, while 140 (72.5%) were fed artificially. All the children underwent RT-PCR test for HIV 5-6 months after their birth: 173 (89.6%) were HIV negative whilst 20 children (10.4%) were HIV positive. Out of the 20 positive children 5/53 (9.4%) had received breast milk for 4 months, while the remaining 15/140 (10.7%) had been fed artificially (P = 0.814). Artificially fed babies (3/140 (2.1%)) and 1/53 (1.9%) of those breast fed for 4 months deceased according to mortality rate of HIV-positive children. This shows that there is no statistically significant difference (P = 0.648) between the mortality of artificially fed (3/140 or 2.1%) and breast-fed (1/53 or 1.9%) children. Artificially fed children (20/140 (14.3%)) and 5/53 (9.4%) of breast-fed children died within 6-10 months. This figure indicates that there is no significant difference between the mortality rate of artificially and that of breast-fed children (P = 0.427). Although the HIV prevention program reduced significantly the vertical transmission of HIV at Saint Camille Medical Center, the mortality of artificially fed children was still high due to gastrointestinal diseases. The HIV diagnosis by RT-PCR technique was of great help in the early identification of HIV-infected children.

Résumé / Abstract : Evaluation des Activités Antibactériennes, Antioxydantes et Antiplasmodiales d’Extraits de quatre Plantes Médicinales de la Pharmacopée Traditionnelle
Doctorat unique

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Résumé / Abstract : The objective of this study was to assess the impact of an alimentary integrator composed of spirulina (Spirulina platensis; SP), produced at the Centre Médical St Camille of Ouagadougou, Burkina Faso, on the nutritional status of undernourished HIV-infected and HIV-negative children. We compared two groups of children: 84 were HIV-infected and 86 were HIV-negative. The duration of the study was 8 weeks. Anthropometric and haematological parameters allowed us to appreciate both the nutritional and biological effect of SP supplement to traditional meals. Rehabilitation with SP shows on average a weight gain of 15 and 25 g/day in HIV-infected and HIV-negative children, respectively. The level of anaemia decreased during the study in all children, but recuperation was less efficient among HIV-infected children. In fact 81.8% of HIV-negative undernourished children recuperated as opposed to 63.6% of HIV-infected children (Z: 1.70 (95% CI -0.366, -0.002, p = 0.088)). Our results confirm that SP is a good food supplement for undernourished children. In particular, rehabilitation with SP also seems to correct anaemia and weight loss in HIV-infected children, and even more quickly in HIV-negative undernourished children.

Résumé / Abstract : Low levels of plasma homocysteine have been found in children and adult populations living in Burkina Faso in association with a low prevalence of coronary heart disease.

Based on this finding, the levels of plasma homocysteine and other thiols (cysteine, cysteinylglycine, glutathione) in postmenopausal women living in Burkina Faso were evaluated with the aim of investigating whether age and life conditions influence plasma homocysteine and other thiol levels.

It was found that in older postmenopausal women the mean level of homocysteine was higher (16.4+/-6.6 micromol/L) than in fertile women (6.8+/-1.2 micromol/L) and that this increase was correlated with cysteine levels (166.6+/-44.6 micromol/L). While the glutathione level in postmenopausal women was lower (3.6+/-2.3 micromol/L) compared with fertile women (7.0+/-1.7 micromol/L), cysteinylglycine levels were within the normal range (29.9+/-9.3 micromol/L). No correlation was found between homocysteine levels and serum folate, vitamin B(12), vitamin B(6), cystatin C and serum creatinine levels. The older the women were, the higher were their plasma homocysteine levels: levels up to 20.2+/-9.1 micromol/L were found in those >70 years old.

The elevated levels of homocysteine in the postmenopausal women of Burkina Faso must be viewed as a characteristic of older age and its metabolic consequences.

Résumé / Abstract : Chitotriosidase (ChT), a protein produced by activated macrophages, belongs to the chitinases, a group of enzymes able to hydrolyze chitin, a structural component of fungi and nematodes. A codominant inherited deficiency in ChT activity is frequently reported in plasma of Caucasian subjects, whereas in the African population this deficiency is rare. This study compares ChT activity in colostrum of 53 African women and 50 Caucasian women. Samples were collected at 24-48 and 72 h after delivery. We found elevated ChT in colostrum of African women on the first day after delivery (1230+/-662 nmol/mL/h) which decreased to 275+/-235 nmol/mL/h on the third day. The ChT activity on the first day after delivery in the colostrum of Caucasian women, however, was significantly lower (293+/-74 nmol/mL/h) and decreased to 25+/-20 and 22+/-19 nmol/mL/h on the 2nd and 3rd day, respectively. The ChT activity in plasma of African women was also higher (101+/-80 nmol/mL/h) than that of Caucasian women (46+/-16 nmol/mL/h), but no correlation was found between plasma and colostrum ChT activity. The elevated ChT activity in colostrum of African women suggests the presence of activated macrophages in human milk, consistent with the genetic characteristics of the African population.

Résumé / Abstract : Five hundred and forty-seven pregnant women with less than 32 weeks of amenorrhoea, attending an antenatal clinic of St. Camille Medical Centre (SCMC) of Ouagadougou were enrolled for a hepatitis C virus (HCV) and HIV co-infection study. Fifty-eight (10.6%) were HIV positive and 18 (3.3%) were anti-HCV positive. Only seven pregnant women (i.e., 1.3%) had a documented HIV and HCV co-infection. HCV-RNA was found in 5 out of 18 (27.8%) patients, who had anti-HCV antibodies. The genotype analysis of these five patients showed that two were of 1b whereas three were of 2a genotype. Mother-to-infant transmission of the same HCV genotype (2a) was documented in only one case. High 1b prevalence has been reported in other parts of Africa, while 2a is the prevalent genotype (60%) in Burkina Faso. This genotype has a higher response rate to treatment. Serum transaminases were normal, also in presence of HCV-RNA. The higher than expected rate of co-infection in Burkina Faso seems to demonstrate a correlation between these two infections, which could influence the evolution of HIV and HCV diseases.

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Résumé / Abstract : In Burkina Faso, in contrast with high rates of Helicobacter pylori infection from an early age, the prevalence of H. pylori-associated diseases (ulcer and gastric cancer) is low.

To look for the prevalence of H. pylori in healthy natives of Burkina Faso, both children and adults.

We studied the prevalence of H. pylori infection in 258 healthy natives of Burkina Faso (70 children aged 6 months-15 years and 188 adults aged 16-65 years), using a serological screening (IgA and IgG H. pylori antibodies). All the studied subjects underwent a questionnaire regarding their life-style, socio-economic status, dietary habits and hygienic sanitary conditions. Data concerning the questionnaire were compared between H. pylori positive and negative subjects.

The rates of H. pylori positivity in children were significantly higher than in adults, and in adults the positivity for H. pylori infection decreased with increasing age. The comparison of the questionnaire's data between H. pylori seropositive and seronegative subjects showed that poor socio-economic status and hygienic sanitary conditions were similar in the two groups. Instead, a higher prevalence of H. pylori positivity was observed in subjects belonging to families living in close contact with sheep, because of their labour and agro-pastoral tradition (shepherds and sedentary farmers).

H. pylori infection in Burkina Faso is acquired early in life and is related not only to some yet well-known risk factors (poor socio-economic and hygienic status), but also to a close contact with sheep. The gradually decreasing H. pylori seropositivity in adult population of Burkina Faso represents an unexplained enigma, which needs further studies.

Résumé / Abstract : Plasmodium falciparum utilises the polyamine pathway, essential in proliferation and differentiation, and imposes an oxidative stress on host cell, enhancing the loss of glutathione.

Standard hematological parameters were determined in 40 black African subjects with acute P. falciparum malaria, 30 aged 5-24 months, 5 aged 4-10 years and 5 aged 19-35 years. Plasma homocysteine, cysteine, glutathione and cysteinylglycine levels were measured by HPLC method. Twenty-eight healthy black children (15 aged 6-24 months and 13 aged 3-10 years) and 20 healthy black adults (aged 20-40 years) were also included as controls.

Plasma homocysteine levels were higher in all subjects with P. falciparum malaria and correlated positively with the disease severity and number of parasites, but negatively with Hb levels and patient ages. Cysteine level was found higher in all patients and markedly higher in 4-10 year old patients. Cysteinylglycine level was found lower particularly in 19-35 year old patients. Glutathione level was significantly lower in all patients.

The elevated level of homocysteine during acute P. falciparum infection suggests an imbalance in the folate cycle, which could be a consequence of the reduced availability of NADPH and Vit B12, caused by increased oxidative stress. This may suggest a selection for the C677T MTHFR allele, driven by P. falciparum in sub-Saharan regions. Hence Hcy level could be useful as a predictive parameter of severity, as well as of treatment efficacy.

Résumé / Abstract : Tandem repeat genetic profiles used in forensic applications varies between populations. Despite the diversity and security issues in the Sahel that require the identification of victims (soldiers and civilians), Burkina Faso (BF) remains understudied. To fill this information gap, 396 unrelated individuals from BF were genotyped using a MICROREADER 21 ID System kit. All 20 short tandem repeat (STR) loci tested passed the Hardy-Weinberg equilibrium (HWE) test. The combined powers of exclusion for duos (CPE duos) and trios (CPE trios) for the 20 tested loci were 0.9999998 and 0.9999307, respectively. The probability that two individuals would share the same DNA profiles among the BF population was 9.80898 × 10-26. For the X-chromosome STR analysis, 292 individuals were included in this study using a MICROREADER 19X Direct ID System kit. Among the 19 loci, no significant deviations from HWE test were observed in female samples after Bonferroni correction (p < 0.05/19 = 0.0026), except for loci GATA165B12 and DXS7423. The results showed that the combined power of exclusion (CPE) and the combined power of discrimination in females (CPDF) and males (CPDM) were 0.999999760893, 0.999999999992, and 1, respectively. Comparison with other African sub-populations showed that geographical proximity is a reliable indicator of genetic relatedness.

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Résumé / Abstract : Human chitotriosidase (Chit) is a member of the chitinase family and it is synthesized by activated macrophages. Recently, a genetic polymorphism was found to be responsible for the common deficiency in Chit activity, frequently encountered in different populations. We analyzed the Chit gene in some ethnic groups from the Mediterranean and African areas, to evaluate whether the Chit gene polymorphism correlates with the changes in environmental features and the disappearance of parasitic diseases. We found a heterozygote frequency for the duplication of 24 bp in exon 10 of 44% in Sicily and 32.71% in Sardinia, whereas those homozygous Chit deficient were 5.45 and 3.73%, respectively. In contrast, in Benin and Burkina Faso, both mesoendemic regions for Plasmodium falciparum malaria and other infections due to intestinal parasites, a low incidence of Chit mutation was found (heterozygous 0 and 2%, respectively) and no subject was homozygous for Chit deficiency. Our results provide evidence of the fact that the low frequency or the absence of mutant Chit gene may represent a protective factor in the population still living in disadvantaged environmental conditions. The present study suggests that the disappearance of parasitic diseases and the improved environmental conditions may have ensued the occurrence of a high percentage of 24-bp mutation in Sicily, in Sardinia and in other Mediterranean countries, whereas in the sub-Saharan regions (Benin and Burkina Faso), the widespread parasitic diseases and the poor social status have contributed to maintenance of the wild-type Chit gene.

Résumé / Abstract : Among strategies to combat malaria, the search for new antimalarial drugs appears to be a priority. Sheering for new antimalarial activities, four plants of the traditional medicine of Burkina Faso: Combretum micranthum, Khaya senegalensis, Pterocarpus erinaceus and Sida acuta, were tested in vitro on fresh clinical isolates of Plasmodium falciparum. The screening showed that Sida acuta has a significant activity (IC50 < 5 microg/ml), and Pterocarpus erinaceus has a moderate activity (5 microg/ml < IC50 < 50 microg/ml). Further chemical screening showed that the activity of the most active plant, Sida acuta, was related to its alkaloid contents.

Résumé / Abstract : Burkina Faso is one of the Subsaharan African nations. No national services for monitoring of antibiotic resistance are available, so the number of reports of resistance patterns among hospital pathogens are inconsistent. In order to evaluate antibiotic resistance, a total of 1998 valuable microrganisms were analysed during 2000 at the Medical Centre St. Camille of Ouagadougou, Burkina Faso's capital. They were isolated as follows: 1012 from urine-culture, 503 from tonsil swabs, 398 from pus, 53 from sputum and 32 from blood-cultures. Escherichia coli was the most isolated microrganism from urine (44%); Enterococcus faecalis from tonsil swabs (96.4%), Staphylococcus aureus from pus (17%) and K. pneumoniae (70%) from sputum. In general, resistance to the old antibiotics, such as aminopenicillins and cotrimoxazole was shown. The most active antibiotic was norfloxacin, a rarely used antibiotic in this country. In conclusion, our study shows that it is necessary to create antibiotic-resistance surveillance centers in the developing countries to adopt an accurate therapy to avoid exporting of antibiotic resistance to the developed countries linked to increased emigration.

Résumé / Abstract : The interaction between pro- and anti-inflammatory cytokines such as interleukin 12 (IL-12), interleukin 18 (IL-18) and transforming growth factor beta (TGF-beta) plays an important role in malaria pathogenesis and outcome, modulating the immunoresponse in Plasmodium falciparum malaria. In our previous studies, we analyzed the plasmatic levels of IL-12, IL-18 and TGF-beta in 105 African children with different degrees of malaria and we correlated the production of these cytokines with the severity of the disease. The aim of the present study was to analyze with a mathematical model, taking into account all the relationships between these cytokines and the parameter variations involved in malaria pathogenesis that influence the results of each type of treatment or therapeutic protocol on patients at different stages of the disease. A mathematical correlation was demonstrated between the levels of pro-inflammatory and anti-inflammatory cytokines, and from this it was possible to build curves of reference in which each patient was positioned based on IL-12 level. Our data, obtained in patients with mild and severe diseases, demonstrate that the levels of IL-12 represent a reliable parameter to predict the progression of the disease, which may be complemented or modulated by administration of IL-18 and TGF-beta. Our findings provide future implications for an immune therapy against the P. falciparum malaria infection, especially in the early phase of the disease showing that a more aggressive outcome may be due to the lack of a balanced immune response.

Résumé / Abstract : Chitotriosidase is a functional chitinase secreted by activated macrophages. It is encoded by a gene located on chromosome 1q31-32, whose mutations may be responsible for chitotriosidase deficiency, encountered in almost 6% of Caucasian population.

This study reports firstly plasma chitotriosidase activity in African children with acute Plasmodium falciparum malaria. The chitotriosidase activity was correlated to objective parameters reflecting the status of the disease and compared with those found in healthy African children.

We found that plasma chitotriosidase levels are significantly increased in African children with acute malaria (185.0+/-141.0 nmol/h/ml; median 150; range 11-521) with respect to reference values obtained in age matched African children (84.4.5+/-72.8 nmol/ml/h; median 63; range 4-350) (P<0.001). Moreover the levels of chitotriosidase were higher in African children than in Caucasian children matched for age (28.86+/-18.7 nmol/h/ml; median 24; range 1-98) (P<0.0001). A remarkable significant correlation was found between plasma chitotriosidase and reticulo-endothelial activation, as judged by thrombocytopenia degree and serum ferritin level in children with acute malaria.

Based on this study, it appears that genetic and environmental features might be responsible for diversity of plasma chitotriosidase activity in black children living in Burkina Faso.

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Résumé / Abstract : Interleukin (IL)-18 produced primarily by mononuclear phagocytes synergizes with IL-12 for interferon-gamma production from T, B and natural killer cells. It has been also demonstrated that, in Plasmodium falciparum malaria, IL-18 could have an immunoregulatory function. The aim of this study was to detect the plasma levels of IL-12 and IL-18, using an enzyme-linked immunosorbent assay, in 105 African children affected by mild and severe Plasmodium falciparum malaria to correlate the production of these cytokines with the severity of the disease. The levels of IL-18 and IL-12 were higher (25.7 +/- 7.6 pg/ml and 17.1 +/- 7.8 pg/ml, respectively) in children with mild malaria than in children with a severe form of the disease (21.5 +/- 10 pg/ml and 13.2 +/- 5.5 pg/ml, respectively). A positive correlation was observed between IL-18 and IL-12. This finding suggests that the production of these two cytokines (IL-18 and IL 12) may be coregulated and both have an immunoregulatory effect on the immune response in Plasmodium falciparum infection.

Résumé / Abstract : The interaction between pro- and anti-inflammatory cytokines such as interleukin 12 (IL-12), interleukin 18 (IL-18) and transforming growth factor beta (TGF-beta) may play an important role in malaria pathogenesis and outcome. IL-18 cooperates with IL-12 in the IFN-gamma production by T, B, and NK cells, and synergizes with IL-12 for IFN-gamma production by Th1 cells. Recently it has been demonstrated that these cytokines modulate the immunoresponse in Plasmodium falciparum malaria. The aim of this study was to measure the plasma levels of IL-12, IL-18 and TGF-beta in 105 African children with various degrees of malaria, and correlate the production of these cytokines with the severity of the disease. IL-12, IL-18 and TGF-beta levels were determined using enzyme-linked immunosorbent assay. The severity of malaria was established by parasitemia, clinical symptoms and haematological parameters. The levels of IL-12, IL-18 and TGF-beta were found to be significantly elevated (15.6 + / - 12.3, 22.7 + / - 13.8 pg/ml and 25.14 + / - 13.22 pg/ml respectively) in all of the children. IL-12 and IL-18 levels were significantly lower (13.2 + / - 5.53 and 21.5 + / - 10 pg/ml pg/ml) in children with severe disease, whereas the level of TGF-beta was higher (28.09 + / - 12.39 pg/ml). In contrast, IL-12 and IL-18 levels were found to be higher (17.32 + / - 7.8 pg/ml and 25.7 + / - 7.6 pg/ml) in patients with mild disease, whereas the level of TGF-beta was lower (20.92 + / - 12.76 pg/ml) compared to the severe malaria group. The correlation between IL-12 and IL-18 demonstrated a progressive relationship up to a value of IL-12 < 25 pg/ml, while IL-18 remained stable at higher levels of IL-12. An inverse correlation was found between IL-12 and TGF-beta up to a value of IL-12 < 30, after which the level of TGF-beta remained stable. This finding suggests that fine mechanisms regulate the interaction between IL-12, IL-18 and TGF-beta in the immune response to Plasmodium falciparum.

Résumé / Abstract : During 1999-2000 a total of 4131 faecal specimens were collected and analysed at the medical centre St. Camille at Ouagadougou. Eight hundred and twenty-six (8.0%) grew significant bacteria. Escherichia coli (35%), Salmonella spp. (15%) and Shigella spp. (10%) were most frequently isolated. A large number of E. coli strains were resistant to aminopenicillins (>90%) and cotrimoxazole (80%); for Yersinia spp the resistance was 80 and 25%, respectively. Norfloxacin was the most active antibiotic but was rarely used. The study showed that it is necessary to create antibiotic-resistance surveillance centres in developing countries so that therapy may be appropriate and the spread of antibiotic resistance to other developed countries via increased emigration may be reduced.

Résumé / Abstract : Interleukin (IL)-12, produced by mononuclear phagocytes, activates the T-helper 1 (Th1) cells and helps, as a mediator, the innate immune response to intracellular microbes. In Plasmodium falciparum infection, this proinflammatory cytokine has immunoregulatory functions with effects on the immune response to the blood stage of disease, but also induces protection and reduces malarial anaemia. In this study, the levels of IL-12 were determined in 73 African children, aged 2-144 months (median 19.5 months), who had severe or mild P. falciparum malaria. IL-12 was determined using the enzyme-linked immunosorbent assay. The levels of IL-12 were found to be significantly elevated (21.6 +/- 18.3 pg/ml) in patients who suffered less severely from the disease. In contrast, the levels of IL-12 were found to be lower (13.1 +/- 7.11 pg/ml) in patients who suffered more severely from the disease.

Résumé / Abstract : The incidence of hemoglobinopathies (Hb C and Hb S) is relatively high in West Africa. In order to characterize the clinical phenotypes of these hemoglobinopathies 10,166 subjects were studied for suspected hemoglobinopathies at the Laboratory of the Centre Medical Saint Camille (CMSC), Ouagadougou, Burkina Faso. A high rate of Hb SC (6.49%) and Hb SS (1.93%) individuals were detected at the CMSC as a consequence of a selective process, whereby patients with anemia or symptoms of vascular occlusive crisis underwent blood tests. The higher frequency of Hb SC may be explained by the fact that this condition is less severe than the SS status, and it requires frequent clinical and laboratory review. On the other hand, the frequency of Hb CC is very low because it does not interfere with their health status. Moreover, the high percentage of Hb S (12.29%) and Hb C (19.28%) trait individuals may be explained by the fact that, in general, all Hb SS and Hb SC patients followed at the CMSC have parents, siblings and other relatives who could have been referred by the center to receive blood tests. The dramatic increase over the past few years in the prevalence of Hb SS [who were absent in the 1984 study of Labie et al. [5]] and of Hb SC, may be attributed to its reduced lethality due to social and health changes. In conclusion, secondary prevention for the control of concurrent and associated diseases is essential in Hb SS and Hb SC patients for improving health and life expectancy.

Résumé / Abstract : The incidence of hemoglobinopathies (Hb C and Hb S) is relatively high in West Africa. In order to calculate the gene frequency of these hemoglobinopathies, 6619 students from 23 local schools in Ouagadougou, Burkina Faso, West Africa, and 2582 individuals living in five villages near Ouagadougou, all situated in Savanna, were studied. As expected, the gene frequency in the city schools was 0.111 for the betaC gene and 0.051 for the betaS gene; in the five villages it was 0.122 for the betaC gene and 0.047 for the betaS gene. This data is somewhat different from that published in a previous study by Labie et al. [2] in the humid Savanna region, that showed a higher prevalence of betaC (0.14) than betaS (0.03), and is in contrast to data from the arid Sahel region that showed a higher prevalence of betaS (0.1) compared to betaC (0.05). The higher rate of betaS and lower rate of betaC in students in Ouagadougou, and in the individuals living in the five villages near Ouagadougou, suggest the possible influence of migratory fluxes of the betaS gene from the country region of Sahel. The dramatic increase in the prevalence of Hb SS patients, not reported in the study of Labie et al., [2] may be the result of reduced mortality due to environmental change. In addition, the improved health conditions of Hb SC and the increased life expectancy of Hb SS, may also have facilitated the increase of the betaS gene and the focus on secondary prevention for the control of correlated diseases.

Résumé / Abstract : Two polymorphic sites, -107 and -100 with respect to the "cap" site of the human beta globin pseudogene, recently discovered in our laboratory, turned out to have an ethnically complementary distribution. The first site is polymorphic in Europeans, North Africans, Indians (Hindu), and Oriental Asians, and monomorphic in sub-Saharan Africans. Conversely, the second site is polymorphic in sub-Saharan African populations and monomorphic in the aforementioned populations. Here we report the gene frequencies of these two polymorphic sites in nine additional populations (Egyptians, Spaniards, Japanese, Chinese, Filipinos, Vietnamese, Africans from Togo and from Benin, and Pygmies), confirming their ethnospecificity and, through the analysis of these two markers in Oromo and Amhara of Ethiopia (two mixed populations), their usefulness in genetic admixture studies. Moreover, we studied another marker polymorphic in sub-Saharan African populations only, a TaqI restriction fragment length polymorphism located in the same region as the present markers, demonstrating the absence of linkage disequilibrium between it and the -100 site, so that we can exclude that the information they provide is redundant.

Résumé / Abstract : Haemoglobin C (HbC; beta6Glu --> Lys) is common in malarious areas of West Africa, especially in Burkina Faso. Conclusive evidence exists on the protective role against severe malaria of haemoglobin S (HbS; beta6Glu --> Val) heterozygosity, whereas conflicting results for the HbC trait have been reported and no epidemiological data exist on the possible role of the HbCC genotype. In vitro studies suggested that HbCC erythrocytes fail to support the growth of P. falciparum but HbC homozygotes with high P. falciparum parasitaemias have been observed. Here we show, in a large case-control study performed in Burkina Faso on 4,348 Mossi subjects, that HbC is associated with a 29% reduction in risk of clinical malaria in HbAC heterozygotes (P = 0.0008) and of 93% in HbCC homozygotes (P = 0.0011). These findings, together with the limited pathology of HbAC and HbCC compared to the severely disadvantaged HbSS and HbSC genotypes and the low betaS gene frequency in the geographic epicentre of betaC, support the hypothesis that, in the long term and in the absence of malaria control, HbC would replace HbS in central West Africa.

Résumé / Abstract : The gene frequencies in 1993-94 for haemoglobin S, haemoglobin C, alpha-3.7 deletional thalassaemia, G6PDA-, HLAB*5301 were estimated in Fulani, Mossi and Rimaibé ethnic groups of Burkina Faso, West Africa. The aim of the study was to verify whether the previously reported Fulani lower susceptibility to Plasmodium falciparum malaria was associated with any of these malaria-resistance genes. Similar frequencies for haemoglobin S were recorded in the 3 ethnic groups (0.024 +/- 0.008, 0.030 +/- 0.011, 0.022 +/- 0.013; in Mossi, Rimaibé and Fulani, respectively). The Mossi and Rimaibé showed higher frequencies when compared to Fulani for haemoglobin C (0.117 +/- 0.018, 0.127 +/- 0.020, 0.059 +/- 0.020), alpha-3.7 deletional thalassaemia (0.227 +/- 0.040, 0.134 +/- 0.032, 0.103 +/- 0.028), G6PDA- (0.196 +/- 0.025, 0.187 +/- 0.044, 0.069 +/- 0.025) and HLA B*5301 (0.189 +/- 0.038, 0.202 +/- 0.041, 0.061 +/- 0.024). Among Fulani the proportion of individuals not having any of these protective alleles was more than 3-fold greater than in the Mossi-Rimaibé group (56.8% vs 16.7%; P < 0.001). These findings exclude the involvement of these genetic factors of resistance to P. falciparum in the lower susceptibility to malaria of Fulani. This evidence, in association with the previously reported higher immune reactivity to malaria of Fulani, further supports the existence in this ethnic group of unknown genetic factor(s) of resistance to malaria probably involved in the regulation of humoral immune responses.

Résumé / Abstract : Chitotriosidase is a functional chitinase secreted by activated macrophages, which is extremely increased in plasma of patients with Gaucher disease (beta-glucocerebrosidase deficiency). Recently, we found that chitotriosidase plasma levels were increased to a variable extent in Sicilian patients with beta-thalassemia major. The aim of this study is to elucidate the possible mechanisms underlying chitotriosidase overproduction in beta-thalassemia major.

Plasma chitotriosidase was measured in 134 patients with beta-thalassemia major (64 from Sardinia and 70 from Sicily), which are treated chronically by blood transfusions leading to systemic iron overload. They all have peripheral anemia and enormous enlargement of the reticulo-endothelial system.

Plasma chitotriosidase activity was found most frequently elevated among Sardinian (48.4%) than Sicilian (17.1%) patients. In either group, the highest levels of plasma chitotriosidase were observed in patients with the highest degree of iron overload, suggesting that this factor could trigger chitotriosidase overproduction.

The higher rate of subjects with increased plasma chitotriosidase values among Sardinian than Sicilian could be related to distinct molecular basis of beta-thalassemia and environmental features.

Résumé / Abstract : Fulani of Burkina Faso (West Africa) are a particularly interesting ethnic group because of their lower susceptibility to Plasmodium falciparum malaria as compared to sympatric populations, Mossi and Rimaibé. Moreover, the occurrence of a Caucasoid component in their genetic make-up has been suggested on the basis of their physical traits and cultural traditions even though this view was not supported by genetic studies. A total of 149 unrelated subjects (53 Mossi, 47 Rimaibé and 49 Fulani) have been typed for 97 HLA class I alleles with the amplification refractory mutation system/polymerase chain reaction (ARMS/PCR) technique. Mossi and Rimaibé data were pooled since none of the 42 statistically testable alleles exhibited a significant heterogeneity. These pooled gene frequencies were found to be very different from those of Fulani: a certain (P<0.001) or a likely (0.001 <P<0.01) difference was found for 5 and 12 alleles, respectively. Four alleles (A*24, A*29, B*27, B*3701) appeared to be essentially "private" Fulani alleles with respect to the other two populations but their presence was not associated with higher resistance to P. falciparum. Our data have then been compared using chord distances (CD) with those from the literature on Africans (including Gambian Fulani) and Caucasoids. The Burkina Faso and Gambian Fulani turned out to be very different (CD=2.191). Moreover, Burkina Faso Fulani were very distant from sympatric Mossi and Rimaibé (CDs=1.912 and 1.884), whereas Gambian Fulani were similar to sympatric Mandinka and Wolof (CDs=0.412 and 0.388) to an extent comparable to that found between Mossi and Rimaibé (CD=0.555). Our study does not suggest the involvement of HLA I in the higher resistance to malaria of Fulani, and confirms a low, if any, Caucasoid component in their gene pool.

Résumé / Abstract : The administration of oral re-hydration solution (ORS) via continuous infusion through a nasogastric (NG) tube and early refeeding facilitates delivery in hospitalised children and the return back home.

the observation was made during a one-year stage in the Camillian Medical Centre (CMC) of Ouagadougou in Burkina Faso. 4,131 infants and children under 5 years old, affected by acute diarrhoea and severe dehydration (loss of weight > 10%) were studied. Those children having difficulties for oral re-hydration were hydrated by continuous infusion through naso-gastric (NG) tube; the NG tube was put in by the nurses and connected to a 500 ml bottle, in which a mixture of glucose and electrolytes was dissolved according to the formula (glucose 20 g + NaCl 3.5 g + NaHCO3 2.5 g KCl 1.5 g in 1 litre of water). The infusion rate was 20-30 drops/minute. No sedative or anti-emetic drug was given, unless in the presence of uncontrolled vomiting. At the end of infusion, flour of millet (60%), soy bean (20%), peanut butter (10%), sugar (10%) and salt (1%) was administered and continued at home or in the nearby areas available for the night.

After 4-5 hrs of infusion 3,717 children (90%) showed a significant gain of weight, although the weight prior to the acute event preceding hospitalisation was never reached during their stay at the CMC. Only 413 children (10%) required a longer period of forced infusion: at the end of the day, however, they were fed with this flour.

A simple strategy, based on a NG infusion plus an oral administration of flour has proven safe and effective in encompassing those difficulties encountered in the treatment and prevention of dehydration in developing countries where the therapy, in children affected by diarrhoea, still represents a major daily occupation.

Résumé / Abstract : A total of 33 trypanosome cryostabilates isolated from domestic animals (bovine and dogs) were analysed using the polymerase chain reaction (PCR). The PCR was undertaken on diluted and treated buffy coat solutions according to an easy protocol of purification, using primers specific to Trypanosoma (Nannomonas) congolense of Savannah, Riverine-Forest, Kilifi and Tsavo types, T. (N) simiae, T. (Trypanozoon) brucei and T. (Duttonella) vivax. The results showed a lack of PCR sensitivity when target solutions were simply diluted, probably a reflection of the inaccuracy of the dilution procedure at very low trypanosome numbers. Nine mixed infections were found in purified samples whereas only three were detected in diluted crude solutions. T. congolense Savannah-type was present in all stabilates. Double infections involving this type with the Riverine-Forest type, T. vivax or T. brucei, were found. One stabilate was found to be infected with the three trypanosome types, namely T. congolense Savannah and Riverine-Forest genotypes and T. vivax. No infection attributable to T. congolense Kilifi and Tsavo types or T. simiae was detected in these stabilates. This work confirmed the abundance of mixed infections in the field, which could not have been detected by the classical parasitological methods. Amongst the T. congolense infections, the Savannah genotype was found to be predominant over the Riverine-Forest type; that could be a consequence of differences in genotype virulence in cattle. The detection of T. congolense Riverine-Forest type in vertebrate hosts living in wet areas could be confirmation of the suspected affinity of relationships between this taxa and the riverine forest tsetse fly species.