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1.
Infect Drug Resist ; 5: 53-63, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22442633

RESUMO

INTRODUCTION: In recent years, intermittent preventive treatment for pregnancy (IPTp) with sulfadoxine-pyrimethamine (SP) has become policy in much of sub-Saharan Africa. But resistance to SP has been spreading across sub-Saharan Africa and thus the effectiveness of IPTp-SP has been questioned. The present study therefore sought to assess the incidence of placental malaria, low birth weight, and anemia of two IPTp-SP approaches (directly observed treatment scheme versus no directly observed treatment) in Anonkoua-Kouté and Samo, Côte d'Ivoire where the reported prevalence of dfr single mutant 108 was 62% and 52.2%, respectively. METHODS: The study was a longitudinal design involving pregnant women and was conducted in Anonkoua-Kouté, a suburban area, and Samo, a rural area, from January 2008 through March 2009. Women of a pregnancy less than 28 weeks duration were randomized to receive SP (1.5 g/0.075 g SP) in a single intake twice and were followed up monthly until delivery. Doses were administered under supervision in the controlled IPTp group, while SP was given free to women in the uncontrolled IPTp group with a recommendation to take it at home. The primary end point was the proportion of low birth weight infants (body weight < 2500 g) and the secondary end point was the rate of severe anemia and placental malaria detected at delivery. RESULTS: A total of 420 pregnant women were enrolled (212 and 208, respectively, in the controlled and uncontrolled groups). Delivery outcome was available for 378 women. In the modified intention-to-treat analysis, low birth weight infants were born from 15.5% of women of the uncontrolled IPTp group and from 11.9% of women in the controlled IPTp group (P = 0.31). The per-protocol population analysis showed consistent results. The proportion of women with placental malaria infection, moderate anemia (hemoglobin < 11 g/dL), and severe anemia (hemoglobin < 8 g/dL) at delivery were similar between the two groups (P > 0.05). CONCLUSION: The study showed that the two approaches were equivalent, suggesting that unsupervised IPTp-SP free of charge should be used in areas where implementation of the directly observed treatment scheme suffers from many constraints.

2.
Transfus Clin Biol ; 16(5-6): 454-9, 2009.
Artigo em Francês | MEDLINE | ID: mdl-19665412

RESUMO

BACKGROUND: Malaria is a real public health problem in Africa; more than 300 million new cases and approximately two million deaths arise every year. In spite of the blood transfusion is a potential way of Plasmodium transmission, there is no consensus for measures to prevent post-transfusion malaria in endemic area. This work aimed at comparing some tools and to discuss various strategies to be implemented. MATERIAL AND METHODS: The study concerned 3001 blood donors recruited in seven blood transfusion centers in Senegal during two periods: dry season (June-July, 2003) and rainy season (October-November, 2003). We evaluated the efficiency of the selection questionnaire for the blood donors to exclude those who are potentially asymptomatic carriers of the Plasmodium. Every donation was screened for pLDH antigen and antibodies against Plasmodium by Elisa technique (DiaMed, Cressier sur Morat, Suisse), morphological tests was also performed, as well as the screening of HIV, HBs Ag, HCV Ab and syphilis. RESULTS: Median age of blood donors was of 27.7 years. Anti-Plasmodium antibodies prevalence was 65.3% and pLDH antigen was of 0.53%, all positivity was confirmed by microscopy. The prevalence of the other infectious markers was 11.7% for HBs Ag; 0.83% for syphilis; 0.49% for HCV Ab and 0.46% for HIV Ab. The risk factors associated with an asymptomatic carrier of Plasmodium were: the rainy season, irregular character of the blood donations, high frequency of malaria attacks in the past, and absence of treatment during the last episode. CONCLUSION: Plasmodium represents the third risk of blood transmitted infectious agents after hepatitis B virus, syphilis, and before HCV and HIV in Senegal. The medical questionnaire is not useful enough for asymptomatic carriers deferral, and we propose to introduce Plasmodium screening. The screening for Plasmodium pLDH by Elisa technique seems to be the best tool in endemic area and the strategy of systematic screening is the most suited in terms of blood transfusion safety.


Assuntos
Doadores de Sangue , Seleção do Doador/métodos , Malária/prevenção & controle , Malária/transmissão , Reação Transfusional , Adolescente , Adulto , África/epidemiologia , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários/sangue , Doenças Endêmicas/prevenção & controle , Feminino , Anticorpos Anti-HIV/sangue , Antígenos de Superfície da Hepatite B/sangue , Anticorpos Anti-Hepatite C/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Plasmodium/imunologia , Estações do Ano , Senegal/epidemiologia , Sífilis/sangue
3.
J Reprod Immunol ; 73(1): 11-9, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16860878

RESUMO

Dendritic cells (DC) are important for induction of primary immune responses and immunological tolerance. Changes in the frequency of DC subsets were analyzed in peripheral blood from pregnant women (mPB) and compared to placental blood (PB) and cord blood (CB). DCs were identified by flow cytometry in whole blood as lineage negative and HLA-DR-positive cells. Different DC subtypes were identified with CD123 and CD11c markers. In these data, the percentage of DC was significantly lower in mPB, PB and CB than in control women, but the absolute number of DC was higher in CB, suggesting that numbers of DC in CB do not explain the decrease of the immune response in newborn infants. Myeloid DCs (MDC) decreased in all compartments of pregnant women compared to control women, especially in mPB where MDC became lower than lymphoid DCs. An increase of less differentiated DC was observed in mPB and CB from pregnant women. DCs in pregnant women were mainly immature DC with a proportion of CD83-positive DC, identical as control women. The levels of IFNgamma, TNFalpha, IL-2, IL-4, IL-5 and IL-10 were not different in the three compartments (mPB, PB, CB). In conclusion, the phenotype and subset of DCs were different in pregnant women than in control women, suggesting a role in maintenance of immune tolerance against the fetus. The distribution of DC subsets was different in mPB, PB and CB. Their role in the regulation of immune response remains to be elicited.


Assuntos
Células Dendríticas/classificação , Sangue Fetal/imunologia , Placenta/imunologia , Gravidez/imunologia , Adulto , Contagem de Células , Citocinas/sangue , Células Dendríticas/citologia , Feminino , Humanos , Senegal
4.
Parasite ; 12(2): 187-9, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15991834

RESUMO

Culturing fresh clinical isolates of P. falciparum and using the isotopic method, we tested separately chloroquine and isradipine--a calcium channel blocker--, and also the combination isradipine plus chloroquine. Tested wild isolates were chloroquine-sensitive. With regard to the combination isradipine/chloroquine, the isobolograms obtained indicate that isradipine antagonises chloroquine antiplasmodial activity. Taking into account these findings, we discuss the issues related to the calcium channel blocker molecules.


Assuntos
Antimaláricos/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Cloroquina/farmacologia , Isradipino/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Animais , Resistência a Medicamentos , Sinergismo Farmacológico , Humanos , Madagáscar , Malária Falciparum/tratamento farmacológico , Testes de Sensibilidade Parasitária
5.
Acta Trop ; 89(2): 193-203, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14732241

RESUMO

A 4-year entomological study was carried out in Southern Madagascar to identify malaria vectors, evaluate the transmission and compare the influence of irrigation in the sub-arid and adjacent humid regions. Three villages were involved in this entomological survey: Androvasoa (located in the natural sub-arid ecosystem), Pépiniére (sited at the centre of an irrigated rice scheme in the sub-arid region) and Esana (bordered with rice fields in the humid region). Mosquitoes were collected inside and outside dwellings when landing on human beings, with light traps and with knockdown indoor sprays. Anopheles arabiensis, Anopheles merus and Anopheles funestus were found in every village while Anopheles gambiae s.s. was only found in the village bordering the rice-fields (Pépiniére) and Anopheles mascarensis, a mosquito native to Madagascar, was only found in the humid region (Esana). In Pépiniére, the annual entomological inoculation rate (EIR) was low (EIR=0.4 infective bites/man/year (IBM)). In the irrigated scheme of the sub-arid region, malaria transmission was 150 times higher (mean EIR=63 IBM) than in the natural ecosystem and A. funestus was the main vector, responsible for 90% of infective bites. In Esana, the level of malaria transmission was high (EIR=41 IBM) and 2/3 of the infective bites were due to A. mascarensis, despite the presence of A. gambiae s.s. and A. funestus. These results are discussed with reference to the impact of irrigation on malaria in Africa ("the paddies paradox").


Assuntos
Anopheles/fisiologia , Insetos Vetores/fisiologia , Malária/transmissão , Animais , Anopheles/parasitologia , Produtos Agrícolas , Ecossistema , Insetos Vetores/parasitologia , Madagáscar/epidemiologia , Malária/sangue , Controle de Mosquitos/métodos , Oryza , Densidade Demográfica , Estações do Ano , Abastecimento de Água
6.
Am J Trop Med Hyg ; 67(2): 137-40, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12389936

RESUMO

To establish a simple definition of a malaria attack based on blood parasite density and other explanatory covariates, a cohort study was conducted from 1993 to 1996 in the Madagascar highlands undergoing a low seasonal transmission of falciparum malaria. Using logistic regression, the explanatory variables found to be significantly related to the risk of fever are parasite density, age, season, and year. However, and in contrast with other studies, we found no evidence of a clear cutoff in parasite density values consistent with the concept of "pyrogenic threshold" despite a gradual increase of the risk of fever with increasing parasite density. Furthermore, the model evidenced an individual-dependent relationship at a given age. This point was in accordance with the immunological data recorded from the participants. The investigators conclude that the parasite density to distinguish malaria attacks from other causes of fever is not reliable in a context of low falciparum transmission.


Assuntos
Suscetibilidade a Doenças , Febre/epidemiologia , Febre/parasitologia , Malária Falciparum/parasitologia , Malária Falciparum/transmissão , Plasmodium falciparum/isolamento & purificação , Adolescente , Adulto , Fatores Etários , Idoso , Animais , Temperatura Corporal , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Madagáscar/epidemiologia , Malária Falciparum/sangue , Malária Falciparum/epidemiologia , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Estações do Ano
7.
Trans R Soc Trop Med Hyg ; 96(2): 143-4, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12055801

RESUMO

In the Madagascar Highlands, 0.76% of children from 168 random primary schools, and 19 of 150 families from 3 villages, had oval-shaped erythrocytes. Most harboured the deletion in the band 3 gene characteristic of South-East Asian ovalocytosis. This genetic trait supports the Indonesian origin of the Madagascar settlement.


Assuntos
Eliptocitose Hereditária/epidemiologia , Adulto , Altitude , Criança , Estudos Transversais , Eliptocitose Hereditária/genética , Emigração e Imigração , Deleção de Genes , Humanos , Madagáscar/epidemiologia , Mutação/genética , Reação em Cadeia da Polimerase/métodos , Prevalência
9.
Arch Inst Pasteur Madagascar ; 68(1-2): 68-72, 2002.
Artigo em Francês | MEDLINE | ID: mdl-12643097

RESUMO

Cultivation of Plasmodium falciparum has been a major research success, leading to a greater understanding of the parasite. Despite the fact that several P. falciparum clones have been maintained in continuous culture in different laboratories, research in genomics and proteomics would require parasitic material produced from fresh wild isolates. We have tested the effect of the supernatant from primary culture of mice hepatocytes on in vitro growth of P. falciparum isolates. Parasitized blood samples were collected from Madagascan malarious patients naturally infected. Isolates proliferation was assessed by use of isotopic method. The asexual erythrocytic stages of P. falciparum were grown for 42 hours in RPMI 1640-based medium plus L15 medium-based supernatant from mice liver cells culture, and in standard RPMI 1640-based medium alone. The mean of parasite growth was 1.5 times greater when the standard medium was enriched with the liver cells layer supernatant at a proportion of 10% and 15% (v/v). The usefulness of P. falciparum ex-vivo culture and of the hepatocytes in vitro primary culture is discussed.


Assuntos
Técnicas de Cultura de Células/métodos , Meios de Cultivo Condicionados/normas , Hepatócitos , Plasmodium falciparum/crescimento & desenvolvimento , Animais , Divisão Celular , Meios de Cultura Livres de Soro/normas , Genômica , Humanos , Madagáscar/epidemiologia , Malária Falciparum/sangue , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Camundongos , Compostos Orgânicos , Plasmodium falciparum/classificação , Plasmodium falciparum/isolamento & purificação , Proteômica , Fatores de Tempo
10.
East Afr Med J ; 79(5): 237-41, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-12638806

RESUMO

OBJECTIVE: To determine how sensitive Plasmodium falciparum is to the major antimalarial drugs in Madagascar. DESIGN: Assessment of Plasmodium falciparum isolates sensitivity to antimalarials, by use of the in-vitro radioisotope method. SETTING: Ankazobe and Saharevo in the foothill areas; and Toamasina and Tolagnaro in the coastal areas (between January 1998 and November 1999). SUBJECTS: Primary Plasmodium falciparum isolates from patients with uncomplicated malaria attack. RESULTS: Between January 1998 and November 1999, of the 293 in-vitro tests done with at least one antimalarial, 70% (205/293) were interpretable. As there was no significant difference between results from the four study sites, the data have been expressed as a whole. All of the successfully tested isolates were sensitive to halofantrine (n = 56) and to quinine (n = 199), 5.8% (12/205) of the isolates were resistant to chloroquine and 2% (4/199) to mefloquine. The geometric mean IC50 was 0.3 microg/L for halofantrine (95% CI = 0.1-0.4 microg/L); 9.4 microg/L for chloroquine (95% CI = 7.3-10.8 microg/L); 3.8 microg/L for mefloquine (95% CI = 3.3-4.3 microg/L); and 26.8 microg/L for quinine (95% CI = 24.3-29.4 microg/L). The low positive correlation found between halofantrine and chloroquine IC50s (n = 56; r = 0.41, P = 0.002) suggests a risk of cross-resistance between these two drugs. CONCLUSION: The degree and frequency of chloroquine resistance in-vitro is stationary in Madagascar compared to previous results during the last decade. The in-vitro sensitivity of P. falciparum to quinine, mefloquine and halofantrine encourages the use of these drugs as alternative in case of chloroquine treatment failure. Nevertheless, it is important to maintain and to extend malaria and drug sensitivity surveillance in Madagascar.


Assuntos
Antimaláricos/farmacologia , Cloroquina/farmacologia , Mefloquina/farmacologia , Fenantrenos/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Quinina/farmacologia , Animais , Avaliação Pré-Clínica de Medicamentos , Resistência a Medicamentos , Hospitais Públicos , Hospitais Urbanos , Humanos , Madagáscar/epidemiologia , Malária Falciparum/tratamento farmacológico , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Testes de Sensibilidade Microbiana , Saúde da População Rural/estatística & dados numéricos
11.
Trans R Soc Trop Med Hyg ; 95(3): 267-9, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11490993

RESUMO

To control the reappearance of malaria in the Madagascan highlands, indoor house-spraying of DDT was conducted from 1993 until 1998. Before the end of the insecticide-spraying programme, a surveillance system was set up to allow rapid identification of new malaria epidemics. When the number of suspected clinical malaria cases notified to the surveillance system exceeds a predetermined threshold, a parasitological survey is carried out in the community to confirm whether or not transmission of falciparum malaria is increasing. Owing to the low specificity of the surveillance system, this confirmation stage is essential to guide the activities of the control programme. For this purpose, Lot Quality Assurance Sampling (LQAS), which usually requires smaller sample sizes, seemed to be a valuable alternative to conventional survey methods. In parallel to a conventional study of Plasmodium falciparum prevalence carried out in 1998, we investigated the ability of LQAS to rapidly classify zones according to a predetermined prevalence level. Two prevalence thresholds (5% and 15%) were tested using various sampling plans. A plan (36, 2), meaning that at least 2 individuals found to be positive among a random sample of 36, enabled us to classify a community correctly with a sensitivity of 100% and a specificity of 94%. LQAS is an effective tool for rapid assessment of falciparum malaria prevalence when monitoring malaria transmission.


Assuntos
Malária Falciparum/prevenção & controle , Vigilância da População/métodos , Garantia da Qualidade dos Cuidados de Saúde/métodos , Criança , Inquéritos Epidemiológicos , Humanos , Madagáscar/epidemiologia , Malária Falciparum/epidemiologia , Parasitologia/métodos , Prevalência , Reprodutibilidade dos Testes , Estudos de Amostragem , Sensibilidade e Especificidade
12.
Ann Trop Med Parasitol ; 95(3): 237-43, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11339883

RESUMO

In Madagascar, although chloroquine (CQ) remains the first-line treatment of choice for malaria, the gradual spread of resistance to this antimalarial drug is of increasing concern. As part of a larger investigation of the effectiveness of the second- and third-line drugs used to treat malaria, the in-vitro susceptibilities of Plasmodium falciparum collected in Madagascar to CQ, mefloquine (MQ) and artemether (ART) were therefore investigated. Median inhibitory concentrations (IC(50)) were determined for isolates collected from residents of two villages in the foothills of the central highlands. The IC(50) for ART ranged from 0.23-17.50 nM [N = 51; geometric mean = 4.02 nM; 95% confidence interval (CI) = 2.99-5.05 nM], four isolates exhibiting IC(50) (> 12 nM) indicative of resistance to this drug. The artemether IC(50) were found to be correlated with those of CQ (N = 46; Spearman's r = 0.51; P = 0.0002), which varied widely (0.4-254.3 nM; mean = 23.4 nM; CI = 7.1-39.7 nM; N = 46). Five (11%) of the 46 isolates exposed to CQ in vitro were considered resistant to this drug (i.e. to have IC(50) > 100 nM), with IC(50) ranging from 109-245.3 nM (mean = 171.6 nM; CI = 110.4-232.8 nM). However, all the CQ-resistant isolates were considered sensitive to ART and vice versa. All the isolates tested also appeared sensitive to MQ (IC(50) = 2.21-43.1 nM; mean = 10.5 nM; CI = 7.95-13.07 nM; N = 46), the IC(50) for MQ being correlated with those for CQ (N = 46; Spearman's r =0.46; P = 0.001). There was no significant correlation between ART and MQ activities. Although the sample was fairly small, the present results indicate that P. falciparum in Madagascar is generally becoming less sensitive to CQ and ART. The observation of a correlation between the IC(50) for these two drugs perhaps indicates that artemisinin derivatives would be better used in combination with antimalarial drugs other than 4-aminoquinolines.


Assuntos
Antimaláricos/farmacologia , Artemisininas , Cloroquina/farmacologia , Mefloquina/farmacologia , Plasmodium falciparum/efeitos dos fármacos , Sesquiterpenos/farmacologia , Animais , Artemeter , Intervalos de Confiança , Resistência a Medicamentos , Quimioterapia Combinada , Humanos , Testes de Sensibilidade Parasitária/métodos , Estatísticas não Paramétricas
13.
Trans R Soc Trop Med Hyg ; 95(1): 14-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11280055

RESUMO

The central region of Madagascar is a vast area of highlands (altitude 700-2000 m). Malaria transmission has re-established itself here since the last epidemic of 1985-90 and has caused the deaths of 40,000 persons according to the Minister of Health. To combat the main malaria vector in the region, Anopheles funestus, annual programmes of indoor house spraying of DDT were carried out between December 1993 and January 1998 in most rural areas at altitude 1000-1500 m. A parasitological and serological study was then conducted in the highland schools to evaluate the impact of the programme and set up a database on the region. Using a cluster-sampling method 2 independent selections were conducted (one of 130 sites, the other of 40 sites). During the study, 13,462 schoolchildren were examined, 71% living in sprayed villages. Parasite prevalence among schoolchildren declined as altitude increases, from 11% at 700-900 m to 0.4% at > 1500 m. Below 1500 m, the impact of the spraying on the prevalence of the parasite was very clear (an average decrease of from 20% to 2.7% below 1000 m and of from 4.5% without spraying to 0.8% at 1000-1500 m). Geographical analysis of the data showed that the marginal regions remained the most affected by malaria (especially outside spraying zones), and persistence of 'pockets of transmission' at 1000-1500 m, essentially in areas where spraying has never been used. In 9 schools, anti-Plasmodium antibodies were sought by indirect immunofluorescence on thick smears of parasitized red blood cells. The seroprevalence ranged from 22% to 63%, which suggests that the parasite is still circulating in the region. Even though our data show that vector control continues to be very successful in the Madagascan highlands, rapid reinfection could occur and must be monitored following spraying. To this end, the Minister for Health, with the support of the Italian Co-operation, has placed the region under epidemiological surveillance since 1997. An alert system for the timely detection of the sources of epidemics and the targeting of the antivectoral campaign is also in operation. Our study suggests that this strategy should be reinforced by the spraying of DDT in the marginal zones in order to consolidate the results obtained at higher altitudes.


Assuntos
DDT/administração & dosagem , Malária Falciparum/epidemiologia , Adolescente , Altitude , Análise de Variância , Criança , Pré-Escolar , Feminino , Humanos , Madagáscar/epidemiologia , Malária Falciparum/prevenção & controle , Masculino , Controle de Mosquitos/métodos , Prevalência , Topografia Médica
14.
Ann Trop Med Parasitol ; 94(4): 313-7, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10945040

RESUMO

Although the national policy for malaria control in Madagascar is to use chloroquine as the first line of treatment, mefloquine has been and is recommended to travellers to the country, both for malaria prevention and cure. The in-vitro susceptibility of Plasmodium falciparum to mefloquine was therefore assessed during a prospective surveillance study in various areas in Madagascar, including the tourist sites of Nosy-be and Sainte Marie. Of the 254 isolates of P. falciparum successfully tested, 232 (90.9%) were sensitive to mefloquine, 12 (4.7%) showed decreased susceptibility (40 nM < IC50 < 50 nM), and 10 (3.9%) were resistant (IC50 > 50 nM). Five (50%) of the resistant strains and nine (75%) of those with decreased susceptibility were from coastal areas or the two tourist sites. The drug pressure that could have induced the resistance observed could therefore be related to the donation of antimalarials, such as mefloquine, by tourists to local populations. The residents of the coastal areas take any donated drugs as self-medication, ignoring recommended doses and durations of treatment. This situation has two main consequences: (1) there is an urgent need to control the abusive and incorrect use of antimalarial drugs in Madagascar, to safeguard the effectiveness of chemotherapy in the future; and (2) these increases in resistance compromise the efficiency of the antimalarial chemoprophylaxis currently recommended to tourists. The use of mefloquine can no longer be considered as a guarantee of protection against malaria in coastal areas and other sites frequented by tourists.


Assuntos
Antimaláricos/uso terapêutico , Malária Falciparum/tratamento farmacológico , Mefloquina/uso terapêutico , Plasmodium falciparum/efeitos dos fármacos , Saúde Pública , Viagem , Animais , Esquema de Medicação , Resistência a Medicamentos , Doenças Endêmicas , Humanos , Madagáscar/epidemiologia , Malária Falciparum/epidemiologia , Estudos Prospectivos
15.
Med Trop (Mars) ; 60(3): 243-9, 2000.
Artigo em Francês | MEDLINE | ID: mdl-11258056

RESUMO

Chloroquine is still the drug of choice for first-line treatment of uncomplicated malaria in Madagascar. However development and spread of chloroquine-resistance could compromise this therapeutic strategy in the future. The purpose of this 1997 study was to compare the efficacy of combined treatment using sulfadoxine and pyrimethamine and single-agent treatment using chloroquine for management of uncomplicated malaria. Study data were collected at four sites in coastal areas of Madagascar where transmission of malaria is perennial. Prevalence of malaria ranged from 15 p. 100 to 22 p. 100 in school children and from 24 p. 100 to 72 p. 100 in outpatient consulting spontaneously at community health centers. All four Plasmodium species affecting man were identified. Plasmodium falciparum was involved in 83 p. 100 of cases. In vivo testing of the susceptibility of Plasmodium falciparum to chloroquine was performed in 149 patients according to the standard simplified 7-day protocol of the WHO. The 35 tests in school children demonstrated no evidence of resistance. However type R1 + R2 resistance was noted in 17 of the 114 tests performed on outpatients, i.e. 14.9 p. 100. In vitro testing demonstrated chloroquine resistance in four of the 90 specimens tested, i.e. 4.4 p. 100. With regard to combined sulfadoxine/pyrimethamine treatment, 45 of 46 in vivo tests in outpatients showed no evidence of resistance. Combination treatment was more effective than single-agent treatment (p = 0.02) and could offer an effective alternative for future use.


Assuntos
Resistência a Medicamentos , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Adolescente , Animais , Criança , Pré-Escolar , Cloroquina/uso terapêutico , Quimioterapia Combinada , Humanos , Madagáscar/epidemiologia , Malária Falciparum/epidemiologia , Malária Falciparum/transmissão , Pirimetamina/administração & dosagem , Pirimetamina/uso terapêutico , Sulfadoxina/administração & dosagem , Sulfadoxina/uso terapêutico
16.
Sante ; 8(4): 257-64, 1998.
Artigo em Francês | MEDLINE | ID: mdl-9794035

RESUMO

Antananarivo has a population of close to one million inhabitants and is located in the highlands of Madagascar. The capital was, until some years ago, thought to be a malaria transmission-free zone. However, between 1985 and 1990, several malaria cases occurred in the suburbs of Antananarivo, along the Ikopa river (the Betsimitatatra Plain), suggesting that local transmission was occurring. Numerous malaria cases have since been reported by health workers each year, but there is insufficient epidemiological information about the cause and origin of the transmission, because cases are rarely confirmed by parasitological examination. The National Malaria Control Management in Madagascar has, after four years of intensive DDT spraying campaigns in the highlands, stopped this specific method of control. Epidemiological follow-up studies will be carried out to evaluate the effects on malaria transmission of this cessation of control measures. The transmission of malaria in Antananarivo was studied from 1995 to 1996. Patients from nine health centers in various suburbs of Antananarivo were included in the study, with the presence of fever used as the sole inclusion criterion. Children randomly selected from schools in the same area were included in a second study group. A blood sample was obtained from each participant to determine the parasite index and the prevalence of antibodies against P. falciparum. The splenic index was also determined. A second assessment was performed for the school children six months later, using the same markers of malaria infection. Nine hundred and thirty two patients from the health center group were referred for participation in the study. This represented 10% of all patients and 74% of the patients with fever. The school group included 1,545 children. The splenic index was similarly low (0.5%) in the health center and school groups, as was the overall parasite index (2.6% for the health center group and 0.8% in the school group). The prevalence of antibodies against P. falciparum was also low, but with a seasonal variation: 2.5% in June 1995 and 11.6% in January 1996. Almost all the cases confirmed by parasitological examination were due to the patient having stayed in an area with hyperendemic malaria or having been in contact with an individual who had been to an area with a high level of transmission. Our findings confirm that Antananarivo is now in a post-epidemic situation. Malaria cases are mostly associated with a history of travel in areas with high levels of malaria transmission, particularly the coastal regions of Madagascar. Nevertheless, a low level of transmission may persist and lead to further outbreaks of malaria in the future, due to the presence in the area of Anopheles arabiensis.


Assuntos
Malária/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Humanos , Lactente , Madagáscar/epidemiologia , Malária/diagnóstico , Malária/prevenção & controle , Malária Falciparum/diagnóstico , Malária Falciparum/epidemiologia , Malária Falciparum/prevenção & controle , Malária Vivax/diagnóstico , Malária Vivax/epidemiologia , Malária Vivax/prevenção & controle , Pessoa de Meia-Idade , Inquéritos e Questionários
17.
Med Trop (Mars) ; 58(3): 261-5, 1998.
Artigo em Francês | MEDLINE | ID: mdl-10088103

RESUMO

Resistance of Plasmodium falciparum to chloroquine was first suspected in Madagascar in 1975 and later confirmed in vivo and in vitro. During the period from 1985 and 1990, the network of public health monitoring stations reported that 1% of the population living on the central Highlands of Madagascar died of malaria. Thereafter the National Malaria Control Program achieved good success by spraying homes with insecticide and reorganizing distribution of chloroquine in all villages. However data recorded between 1996 and 1998 indicates that, after four years of widespread chloroquine use, resistance to amino-4-quinolones is progressing in Madagascar. The tests described in this report were performed on patients with documented malaria included in cohorts and followed year round by a physician. The three villages studied were located along the borders of the highlands between the plateaus and coastal areas. In vivo tests showed that the incidence of chloroquine resistance was 0% in Mahakary, 32% in Ankazobe and 30% in Saharivo. Clinically, however, treatment was unsuccessful in only 16% and 8% of cases respectively. In vitro tests demonstrated chloroquine sensitivity in 79% of the 153 strains tested. No resistance to quinine or halofantrine was observed. In vitro tests indicated an onset of resistance to mefloquine. Although the success rate of chloroquine treatment is nearly 80%, spread of strongly chloroquine-resistant strains is a risk especially in subjects with mild immunity to malaria.


Assuntos
Controle de Doenças Transmissíveis , Insetos Vetores , Malária/prevenção & controle , Plasmodium falciparum/efeitos dos fármacos , Animais , Antimaláricos/uso terapêutico , Cloroquina/uso terapêutico , Resistência Microbiana a Medicamentos , Humanos , Madagáscar , Malária/transmissão , Testes de Sensibilidade Microbiana , Estudos Retrospectivos
20.
Biochem J ; 324 ( Pt 3): 863-7, 1997 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-9235879

RESUMO

Adenovirus is a vector for the delivery of genes mainly to the liver. Short-term (approximately 3 days) studies using adenovirus transfection have provided valuable insights into how genes can complement normal and pathological phenotypes. When atherosclerosis-susceptible C57BL/6 mice were infected with an adenovirus vector containing the human 7alpha-hydroxylate cDNA (AV17h1) and fed on a chow diet, human 7alpha-hydroxylase mRNA and enzyme activity doubled compared with that in mice infected with an adenovirus vector (AV1Null) alone. In AV17h1-infected mice fed on a high fat cholic acid (HFCA) diet, mRNA expression and activity of both the endogenous and adenovirus (human) 7alpha-hydroxylase were repressed. AV17h1-infected mice fed on a HFCA diet and killed at mid-light had increased 7alpha-hydroxylase activity and mRNA compared with mice killed at mid-dark. Since expression of AV17h1 is driven by a constitutive Rous sarcoma virus promoter, the repression of human 7alpha-hydroxylase by the HFCA diet was unexpected. In spite of this post-transcriptional repression by the HFCA diet, AV17h1-infected mice expressed the human 7alpha-hydroxylase mRNA, causing its enzyme activity to be 3-fold greater than in AV1Null-infected mice. In AV17h1-infected mice, the 7alpha-hydroxylase enzyme activity varied as a linear function of human mRNA abundance. In conclusion, the accumulation of apolipoprotein B-containing lipoproteins in plasma of C57BL/6 mice fed on the HFCA diet was not reduced by longer-term (2 weeks) 7alpha-hydroxylase expression, probably because of its diminished expression caused by the diet and hepatic inflammation from the adenovirus infection. These results may suggest that adenovirus is effective in promoting longer-term (2 weeks) expression of 7alpha-hydroxylase.


Assuntos
Infecções por Adenoviridae/genética , Arteriosclerose/enzimologia , Colesterol 7-alfa-Hidroxilase/genética , Animais , Arteriosclerose/genética , Colesterol/sangue , Colesterol 7-alfa-Hidroxilase/metabolismo , Gorduras na Dieta/administração & dosagem , Feminino , Predisposição Genética para Doença , Humanos , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/genética
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