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1.
Artigo em Francês | AIM (África) | ID: biblio-1271839

RESUMO

Le programme national de lutte contre le paludisme avec ses partenaires a entrepris des formations des prestataires sur les nouvelles directives de prise en charge des cas de paludisme dans les formations sanitaires du pays. Cette étude visait à mesurer l'effet desdites formations sur les pratiques des prestataires formés. Elle s'est déroulée dans les structures de premier contact de la commune V du district de Bamako. Il s'agissait d'une étude transversale portant sur les données de 3 mois avant et après la formation à partir des registres de consultation. La fièvre était le symptôme le plus fréquent avec 34,7 % avant la formation et 33,6 % après la formation. La majorité des patients a bénéficié d'un examen biologique soit 57,9 % avant la formation et 60,5 % après la formation. Le paludisme simple a représenté 35,4% avant la formation et 37,9 % après la formation contre respectivement 34,8 % et 34,3 % pour le paludisme grave. Cependant, 29,8 % des patients avant la formation et 27,8 % après la formation n'ont pas été classés conformément aux normes nationales. Parmi les cas de paludisme simple, 45,3 % ont été traités correctement avant la formation contre 57,6 % après la formation. Pour le paludisme grave, les taux de traitement correct étaient de 75,5 % avant la formation contre 72,1 % après la formation. La formation des prestataires a eu un effet modéré sur la qualité de la prise en charge des cas de paludisme dans les structures concernées. La supervision postformation ou la formations des prestataires à la tâche pourrait améliorer la situation


Assuntos
Centros Comunitários de Saúde , Gerenciamento Clínico , Pessoal de Saúde , Capacitação em Serviço , Malária/diagnóstico , Mali
2.
New Microbes New Infect ; 7: 100-4, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26442153

RESUMO

Bacterial bloodstream infections (BSI) account for considerable morbidity worldwide, but epidemiological data from resource-constrained tropical settings are scarce. We analysed 293 blood cultures from patients presenting to a regional referral hospital in Bouaké, central Côte d'Ivoire, to determine the aetiology of community-onset BSI. The prevalence of bacteraemia was 22.5%, with children being most commonly affected. Enterobacteriaceae (predominantly Klebsiella pneumoniae and Salmonella enterica) accounted for 94% of BSI. Staphylococcus aureus was the only relevant Gram-positive pathogen. Clinical signs and symptoms were not significantly associated with blood culture positivity after controlling for malaria.

3.
Parasite Immunol ; 30(1): 47-51, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18086016

RESUMO

Plasmodium falciparum infection can lead to a life threatening disease and the pathogenetic mechanisms of severe manifestations are not fully understood. Here, we investigated the capacity of P. falciparum-parasitized red blood cells (PRBC) from 45 children with clinical malaria to induce endothelial cell (EC) apoptosis. In all subjects, PRBC that cytoadhered to ECs could be found albeit to a variable degree. By contrast, PRBC that induce EC apoptosis were found only in nine (20%) subjects. Interestingly, children with neurological manifestations were significantly more likely to harbour apoptogenic strains. There was no quantitative relationship between the capacity of these isolates to cytoadhere and apoptosis induction. We hypothesize that P. falciparum-encoded molecules could be responsible for apoptosis induction and therefore suggest new insights in the pathogenesis of P. falciparum malaria. Further investigations are currently in progress to determine whether these results can be confirmed and to identify putative parasite apoptogenic factors.


Assuntos
Apoptose , Células Endoteliais/patologia , Eritrócitos/fisiologia , Eritrócitos/parasitologia , Malária Falciparum/parasitologia , Doenças do Sistema Nervoso/parasitologia , Plasmodium falciparum/patogenicidade , Animais , Adesão Celular , Células Cultivadas , Criança , Pré-Escolar , Células Endoteliais/metabolismo , Humanos , Lactente , Malária Cerebral/parasitologia , Malária Falciparum/sangue , Malária Falciparum/patologia , Doenças do Sistema Nervoso/metabolismo , Doenças do Sistema Nervoso/patologia , Parasitemia , Plasmodium falciparum/isolamento & purificação
4.
Dakar Med ; 53(3): 260-6, 2008.
Artigo em Francês | MEDLINE | ID: mdl-19626800

RESUMO

INTRODUCTION: Post-operative Peritonitis (PPO) put some diagnostic and therapeutic problems to surgeons. The aim of the study was: first, to analyze the epidemiological, diagnostic, and therapeutic factors of post-operative peritonitis; then, to define a strategy to improve their prognosis. MATERIAL AND METHOD: We did a retrospective study carried out at department of general surgery of the Aristide Le Dantec hospital from January 2001 to March 2007 on cases of PPO. Fifteen cases were included. It was about 12 men and 3 women of middle age of 38.2 years with extremes of 17 and 70 years. RESULTS: Clinical signs were dominated by the abdominal pain (73.3%) and the fever (66.7%). Abdominal collections were multi-microbial. The digestive suture failure was the dominant reason. All patients have been managed in the 48 hours that followed the diagnosis of PPO. The treatment consisted, essentialy in temporary digestive derivation, washing and drainage of the abdominal cavity framed by an adequate resuscitation. The recovery was 67.7%. Morbidity rate is 33.3%. Mortality concerned 5 patient (33.3%) especially carriers of 2 or 3 visceral failings. Criteria of precocious re-laparotomy have been specified. CONCLUSION: The improvement of the prognosis passes indeed by a precocious diagnosis and a coherent multidisci lina a roach.


Assuntos
Peritonite/diagnóstico , Peritonite/etiologia , Complicações Pós-Operatórias , Dor Abdominal/etiologia , Adolescente , Adulto , Idoso , Feminino , Febre/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Peritonite/terapia , Estudos Retrospectivos , Adulto Jovem
5.
Int J Parasitol ; 36(5): 529-40, 2006 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-16600243

RESUMO

Malaria and human African trypanosomiasis represent the two major tropical vector-transmitted protozoan infections, displaying different prevalence and epidemiological patterns. Death occurs mainly due to neurological complications which are initiated at the blood-brain barrier level. Adapted host-immune responses present differences but also similarities in blood-brain barrier/parasite interactions for these diseases: these are the focus of this review. We describe and compare parasite evasion mechanisms, the initiating mechanisms of central nervous system pathology and major clinical and neuropathological features. Finally, we highlight the common immune mediated mechanisms leading to brain involvement. In both diseases neurological damage is caused mainly by cytokines (interferon-gamma, tumour necrosis factor-alpha and IL-10), nitric oxide and endothelial cell apoptosis. Such a comparative analysis is expected to be useful in the comprehension of disease mechanisms, which may in turn have implications for treatment strategies.


Assuntos
Malária Cerebral/imunologia , Meningoencefalite/parasitologia , Tripanossomíase Africana/imunologia , Animais , Barreira Hematoencefálica/imunologia , Infecções Protozoárias do Sistema Nervoso Central/imunologia , Interações Hospedeiro-Parasita/imunologia , Humanos , Plasmodium falciparum/fisiologia , Trypanosoma brucei gambiense/fisiologia , Trypanosoma brucei rhodesiense/fisiologia
6.
Mali Med ; 21(3): 23-7, 2006.
Artigo em Francês | MEDLINE | ID: mdl-19435003

RESUMO

Authors bring back their experience in surgery thyroïdienne patient sur192s admitted and operated in five years in tea service of General Surgery of him FALLEN Ignace Deen Conakry of. Thesis patients represented 3.13% of tea 6139 surgical interventions exercised during tea period of survey. It was about has retrospective survey of descriptive type going from January 1st, 1997 at 31 December 2001, structural one aspects epidemiological, clinic, therapeutic and histologique. Tea done operative gesture was 86 lefts loboisthmectomieseses (44.17%), 41 rights loboisthmectomieseses (21.35%), 58 thyroidectomies subtotales (30.21%), 7 thyroidectomieses total (3.65%). Tea gotten results were good in 99.48%. To slot of death has been recorded, representing 0.52%. Tea goalkeeper of tea survey was to appreciate results of surgery thyroidienne and to take out again elements of bad prognostication of this surgery in their service.


Assuntos
Glândula Tireoide/cirurgia , Tireoidectomia/estatística & dados numéricos , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Guiné , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Doenças da Glândula Tireoide/cirurgia , Adulto Jovem
8.
Acta Trop ; 85(3): 355-61, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12659973

RESUMO

To assess the relationships between variations of Plasmodium falciparum transmission and those of peripheral parasitaemia prevalence or malaria attack incidence rates in regions with limited fluctuations of transmission, we conducted a follow-up in two Gabonese populations. Entomological surveys were carried out from May 1995 to April 1996 in Dienga, and from May 1998 to April 1999 in Benguia. In Dienga, malaria transmission was seasonal, being not detected during two 3-month periods. Mean entomological inoculation rate (EIR) was 0.28 infective bite/person/night. In Benguia, malaria transmission was perennial with seasonal fluctuations, mean EIR being 0.76 infective bite/person/night. In Dienga, 301 schoolchildren were followed from October 1995 to March 1996. Clinical malaria attack was defined as fever associated with >5000 parasites/microl of blood. P. falciparum prevalence varied from 28 to 42%, and monthly malaria attack incidence from 30 to 169 per thousand. In Benguia, the entire population (122 persons) was followed from November 1998 to April 1999. Prevalence varied from 22 to 50%, and monthly malaria attack incidence from 52 to 179 per thousand. In each area, entomological variations were not related to parasite prevalence, but preceded malaria attack incidence with 1- or 2-month time lag, corresponding to the pre-patency period that differs in the two populations, possibly according to differences in immunity related to parasite transmission.


Assuntos
Anopheles/crescimento & desenvolvimento , Mordeduras e Picadas de Insetos/parasitologia , Malária Falciparum/epidemiologia , Malária Falciparum/transmissão , Plasmodium falciparum/isolamento & purificação , Adolescente , Adulto , Idoso , Animais , Anopheles/parasitologia , Criança , Pré-Escolar , Estudos de Coortes , Gabão/epidemiologia , Humanos , Incidência , Lactente , Mordeduras e Picadas de Insetos/epidemiologia , Estudos Longitudinais , Malária Falciparum/parasitologia , Pessoa de Meia-Idade , Parasitemia/epidemiologia , Prevalência , População Rural , Estações do Ano
9.
Trop Med Int Health ; 6(10): 767-9, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11679124

RESUMO

We have designed primers to the conserved region of the erythrocyte binding antigen (EBA)-175 gene which amplify specifically the two alleles by polymerase chain reaction (PCR) and by nested PCR. This approach provides a specific, sensitive and rapid method for genotype determination in a large number of Plasmodium falciparum field isolates.


Assuntos
Antígenos de Protozoários/genética , Proteínas de Transporte/genética , Primers do DNA , Plasmodium falciparum/genética , Reação em Cadeia da Polimerase/normas , Proteínas de Protozoários/genética , Animais , Genótipo , Humanos , Malária Falciparum/epidemiologia , Sensibilidade e Especificidade
10.
J Clin Microbiol ; 38(12): 4681-2, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11101625

RESUMO

Pasteurella dagmatis was identified as the etiologic agent of peritonitis in a continuous ambulatory peritoneal dialysis patient by utilizing a molecular kit in our hospital's clinical laboratory. This method would appear a useful approach to identify a species of Pasteurella not included in the existing database of commercial identification kits when discrepancies exist between phenotypic tests.


Assuntos
Pasteurella/isolamento & purificação , Diálise Peritoneal Ambulatorial Contínua/efeitos adversos , Peritonite/microbiologia , Adulto , Feminino , Humanos
11.
Trop Med Int Health ; 4(11): 719-27, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10588765

RESUMO

Natural killer (NK) cell activity is impaired in Chlamydia trachomatis-infected patients. The mechanisms behind the altered NK functions are not clear, but data concerning NK and antibody-dependent cellular cytotoxicity (ADCC) activity have been reported. To investigate whether this impairment is related to a defect at the target cell binding and/or the postbinding level, we evaluated highly purified NK cells obtained from 125 C. trachomatis-infected patients and compared them with 101 normal controls for their ability to kill K-562 and U-937 cell lines using a 51Cr release assay; release tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma); and kill anti-IgM preincubated P-815 cell line (ADCC activity). We found a decrease in the lytic capability of NK cells from C. trachomatis-infected patients against target cell lines; decreased ability to kill bound target cells; and low levels of released TNF-alpha and INF-gamma after incubation with U-937 cells. Taken together, these findings suggest that the impaired NK cell reaction during chlamydial infection is related to defects both at the target and postbinding levels. However, the precise mechanisms remain to be determined. The inability to restore normal NK activity after long-term culture in the presence of high levels of recombinant IL-2 support the hypothesis of an anergic process during chlamydial infection.


Assuntos
Infecções por Chlamydia/imunologia , Chlamydia trachomatis/imunologia , Células Matadoras Naturais/imunologia , Adolescente , Adulto , Antígenos CD/biossíntese , Linhagem Celular , Chlamydia trachomatis/isolamento & purificação , Técnicas de Cocultura , Testes Imunológicos de Citotoxicidade , Feminino , Imunofluorescência , Humanos , Interferon-alfa/biossíntese , Interferon gama/biossíntese , Interferon gama/farmacologia , Interleucina-2/farmacologia , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/metabolismo , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Subpopulações de Linfócitos/efeitos dos fármacos , Subpopulações de Linfócitos/imunologia , Subpopulações de Linfócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/biossíntese
12.
Bull Soc Pathol Exot ; 92(3): 167-70, 1999 Jul.
Artigo em Francês | MEDLINE | ID: mdl-10472442

RESUMO

By evaluating the diagnostic methods developed in our laboratory, the prevalence of loaiosis was estimated among 201 individuals from the province of Haut Ogooué in Gabon using IgG4 serology and nested-PCR. The study showed that the prevalence of loaiosis was higher than that described using standard microscopy. IgG4-based ELISA (Enzyme Linked Immunosorbant Assay) using crude extract of Loa loa microfilariae showed that 80% (35/44) of microfilaraemic individuals (MF') and 56% (88/157) of amicrofilaraemics (AMF) presented antibodies. By contrast, L. loa specific DNA amplified by nested-PCR was detected in all MF and in 68% (106/157) of AMF. Among the 201 samples tested, 95 (47%) gave positive results in both tests. These results indicate that the presence of IgG4 antibodies directed against crude extract of L. loa microfilariae is not linked to the positivity of nested-PCR assay (chi 2 for paired data = 8.78; P < 0.02). We conclude that the PCR assay is more sensitive than the detection of IgG4 antibodies (directed against crude extract of L. loa microfilariae) in detecting loaiosis, and particularly occult loaiosis (infection without circulating microfilariae).


Assuntos
Imunoglobulina G/sangue , Loa/genética , Loa/imunologia , Loíase/diagnóstico , Reação em Cadeia da Polimerase , Animais , Anticorpos Anti-Helmínticos/sangue , DNA de Helmintos/sangue , Ensaio de Imunoadsorção Enzimática , Gabão , Humanos , Loíase/parasitologia
13.
J Med Primatol ; 28(2): 57-61, 1999 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10431694

RESUMO

The human and simian strains of Loa loa microfilariae are morphologically identical even though their periodicities vary. When using primate models (Mandrillus sphinx) of human loaisis for vaccination trials, the absence of any ongoing simian L. loa infection must be demonstrated. Nested primers derived from a human strain of L. loa (targeted on the repeat 3 region of the gene encoding the 15 kDa polyprotein; 15r3) amplified at 366 bp sequence from simian L. loa genomic DNA and blood lysates from mandrills infected with simian L. loa. This nested-PCR assay has been tested on 12 amicrofilaremic (AMF) mandrills (without filarial microfilariae) and was positive in four mandrills. The nested-PCR product derived from simian L. loa genomic DNA and from three of four AMF mandrills has been sequenced. No difference was observed between the four sequences, which, in addition, were 99.18% identical to the 15r3 of human L. loa. Therefore, the 15r3 sequence is conserved within human and simian L. loa. These results suggest that the four PCR-positive mandrills without circulating microfilariae had occult simian L. loa infections. The study demonstrates the ability of a nested-PCR assay to identify animals naturally infected with simian L. loa.


Assuntos
Antígenos de Helmintos/genética , Sequência Conservada/genética , Proteínas de Helminto/genética , Loa/genética , Loíase/parasitologia , Doenças dos Macacos/parasitologia , Sequências Repetitivas de Ácido Nucleico/genética , Animais , Sequência de Bases , DNA de Helmintos/genética , DNA de Helmintos/isolamento & purificação , Humanos , Loa/isolamento & purificação , Loíase/veterinária , Dados de Sequência Molecular , Reação em Cadeia da Polimerase/métodos , Análise de Sequência de DNA
14.
Clin Diagn Lab Immunol ; 6(2): 254-9, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10066663

RESUMO

All NK cells potentially lytic for autologous cells but not expressing self-major histocompatibility complex (MHC)-reactive receptors could be eliminated by a negative selection mechanism during ontogeny. This idea is based on the existence of a NK cell subset expressing a specific inhibitory receptor for allogeneic MHC alleles. As ancestral haplotypes of the MHC appear to define identical MHC haplotypes in unrelated individuals, unrelated individuals having the same ancestral haplotype should also have the same NK-defined allospecificities that have been shown to map to the human MHC. To test this prediction, multiple cell lines from unrelated individuals having the same ancestral haplotypes were tested for the NK-defined allospecificities. It was found that cells having the same ancestral haplotypes do have the same NK-defined specificities. Furthermore, the NK-defined phenotype of cells that possess two different ancestral haplotypes can be predicted from the NK-defined phenotypes of unrelated cells that are homozygous for the ancestral haplotypes concerned. Although the group 1 and 2 NK-defined allospecificities can be explained to some extent by HLA-C alleles, evidence is presented that additional genes may modify the phenotype conferred by HLA-C.


Assuntos
Epitopos/imunologia , Células Matadoras Naturais/imunologia , Complexo Principal de Histocompatibilidade/imunologia , Alelos , Biomarcadores , Testes Imunológicos de Citotoxicidade , Haplótipos , Humanos , Complexo Principal de Histocompatibilidade/genética , Polimorfismo de Fragmento de Restrição
15.
J Med Primatol ; 28(6): 307-17, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10733203

RESUMO

We have previously demonstrated that peptide immunization restimulates the memory CD4 T-cell response, but fails to induce cytotoxic T lymphocyte (CTL) in cynomolgus macaques. To examine the nature of protective immunity to simian immunodeficiency virus (SIV) in this study, freshly isolated peripheral blood mononuclear cells (PBMC) from four infected juvenile cynomolgus macaques and from three uninfected control macaques were assessed for CTL activity monthly for 9 consecutive months, beginning 1 month after detection of infection. Target cells consisted of major histocompatibility (MHC) haploidentical parental PBMC which were stimulated with mitogen and then pulsed with heat-killed SIVcyn. CTL activity was demonstrated in PBMCs from all four infected animals. The effector cells are T cells which mediate cytotoxicity against SIVcyn-pulsed target cells in an MHC-restricted manner. Furthermore, the cytotoxicity is virus specific and predominantly, if not exclusively, mediated by CD8+ T cells; it is also MHC class I restricted. Incubation of target cells with pepstatin A during antigen pulsing prior to the cytotoxic assay inhibited target cell generation, suggesting that viral antigens are processed via an endocytic pathway.


Assuntos
Macaca fascicularis , Doenças dos Macacos/virologia , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/patogenicidade , Linfócitos T Citotóxicos/imunologia , Animais , Genes MHC Classe I/imunologia , Mitógenos , Doenças dos Macacos/imunologia , Monócitos/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia , Linfócitos T Citotóxicos/virologia
16.
Am J Trop Med Hyg ; 61(6): 956-9, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10674677

RESUMO

Mandrills (Mandrillus sphinx) experimentally infected with human Loa loa usually remain microfilaremic for a long period of time. Nevertheless some control their microfilaremia while still harboring adults worms, and therefore become occult-infected. A nested polymerase chain reaction (PCR) assay, targeted on the repeat 3 region of the gene coding for the L. loa 15-kD protein (15r3-PCR), has been evaluated in mandrills infected with third-stage larvae (L3) of L. loa. The results of this assay were negative during the prepatency period (4 months after inoculation), but became positive when microfilariae appeared in the blood, and remained positive in all mandrills, even in those that became amicrofilaremic. These results show that the positivity of the 15r3-PCR assay is linked to the appearance of microfilariae in peripheral blood and demonstrated that L. loa-specific DNA can be detected in blood from occult-infected mandrills.


Assuntos
DNA de Helmintos/sangue , Loa/isolamento & purificação , Loíase/diagnóstico , Reação em Cadeia da Polimerase/normas , Animais , Primers do DNA , Seguimentos , Humanos , Loa/genética , Loíase/sangue , Microfilárias/genética , Microfilárias/isolamento & purificação , Papio/parasitologia , Sensibilidade e Especificidade
17.
Med Trop (Mars) ; 59(3): 249-52, 1999.
Artigo em Francês | MEDLINE | ID: mdl-10701202

RESUMO

Filarial loiasis differs from other filariases in that most infected subjects are amicrofilaremic. This difference raises the notion of occult infection. The aim of this study was to evaluate the relationship between the intensity of transmission and incidence of infection. For this purpose we determined the incidence of loiasis both microscopically and by PCR in 201 subjects from three villages in the province of Haut Ogooue in Gabon. Intensity of transmission, expressed in ATP (annual transmission potential) in these villages was estimated to be 250 infecting larvae per individual per year (L3/man/yr) in Moyabi, 180 L3/man/yr in N'dokaye, and 43,000 L3/man/yr in Okoumbi. Although there was no significant difference between the three villages with regard to the incidence of microfilaremia (21 p. 100 and 22 p. 100), the incidence of occult infection, i.e., positive PCR in amicrofilaremic subjects, was 45 p. 100 in Moyabi, 79 p. 100 in N'dokaye and 80 p. 100 in Okoumbi. The overall incidence of loiasis was 57 p. 100 in Moyabi and 85 p. 100 in both N'dokaye and Okoumbi. These findings demonstrate that the incidence of loiasis is correlated with the intensity of transmission (p < 0.001), especially in children. Taking this information into account will improve control of Loa loa in endemic areas.


Assuntos
Loíase/epidemiologia , Loíase/transmissão , Adolescente , Adulto , Distribuição por Idade , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , DNA de Helmintos/análise , DNA de Helmintos/genética , Gabão/epidemiologia , Humanos , Incidência , Loa/genética , Loíase/sangue , Loíase/diagnóstico , Loíase/parasitologia , Programas de Rastreamento/métodos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Vigilância da População , Prevalência
18.
Am J Trop Med Hyg ; 59(1): 144-9, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9684643

RESUMO

The development of control strategies for loiasis is of crucial importance in endemic areas and depends heavily on the accurate identification of occult-infected individuals. A polymerase chain reaction (PCR) and nested polymerase chain reaction (nested PCR) were developed and based on sequences of the repeat 3 region (15r3) of the gene encoding a Loa loa 15-kD protein. The assays was performed on 20 blood samples from occult-infected subjects and 30 from field-collected amicrofilaremic individuals. The size of the initial PCR product was 396 basepairs (bp). When this initial amplification using primers 15r3(1) and 15r3(2) was carried out for 30 cycles, the PCR products from three of the 20 occult-infected and five of the 30 amicrofilaremic individuals were visualized after electrophoresis by staining the gel with ethidium bromide. Subsequent Southern blotting and hybridization with the specific probe revealed hybridization in 19 of 20 occult-infected and 23 of 30 amicrofilaremic samples but only after two days of exposure of the blot to the x-ray film. When the nested PCR was carried out (product size = 366 bp, primers 15r3(3) and 15r3(4)), 19 of 20 occult-infected and 23 of 30 amicrofilaremic samples that were positive by Southern hybridization of the initial PCR products were strongly positive by staining with ethidium bromide. Qualitative Southern blotting of the nested PCR products using the same probe previously described confirmed the ethidium bromide staining results after a very short exposure time of 4 hr. These results demonstrate that the nested PCR amplification product is specific and that its sensitivity in detecting occult loiasis is 95%. This approach has significant promise for the screening of large human populations for active loiasis without the requirement for blotting and hybridization of the PCR products.


Assuntos
DNA de Helmintos/sangue , Loa/genética , Loíase/diagnóstico , Reação em Cadeia da Polimerase/métodos , Animais , Primers do DNA/química , Eletroforese em Gel de Ágar , Proteínas de Helminto/genética , Humanos , Loa/isolamento & purificação , Sensibilidade e Especificidade
19.
Trop Med Int Health ; 3(6): 505-11, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9657514

RESUMO

A nested polymerase chain reaction (nested PCR) assay, targeted on the repeat 3 region (15r3) of the gene coding for a Loa loa 15 kD polyprotein, was developed to detect L. loa infection. The assay has a sensitivity of 95% and is 100% specific with regard to sympatric filarial parasites: Mansonella perstans, Onchocerca volvulus and Wuchereria bancrofti. In this field study in a mixed filarial (L. loa and M. perstans) endemic region of Gabon, 157 L. loa amicrofilaraemic blood samples (AMF; diagnosed by leucoconcentration followed by standard microscopic examination) from the residents from four villages were screened by the 15r3-nested PCR assay. The assay detected 106 occult infected subjects among the 157 AMF individuals (68%), including 59 of 87 adults (68%) and 47 of 70 children (67%). In each village the prevalence of occult infection was, respectively, 38%, 52%, 79% and 80% for Moyabi, Djoutou, N'djokaye and Okoumbi. The annual transmission potential (ATP) of loiasis has been estimated to be 250 infective larvae (L 3) per man per year for Moyabi and Djoutou, 1800 for N'djokaye and 433000 L3/man/year for Okoumbi. This implies a correlation between occult infection of loiasis and the intensity of transmission. By contrast, the prevalence of L. loa microfilariae was 21% for Okoumbi, 22%, for N'djokaye and 19% for Djoutou and Moyabi. These results show that the prevalence of loiasis in this region of Gabon is higher than previously described by standard microscopic examination and that the application of this assay will be significant in the development of control strategies for loiasis.


Assuntos
Loíase/diagnóstico , Reação em Cadeia da Polimerase , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Primers do DNA , Diagnóstico Diferencial , Feminino , Gabão/epidemiologia , Humanos , Loíase/epidemiologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Prevalência , Sensibilidade e Especificidade
20.
Trop Med Int Health ; 3(4): 313-7, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9623933

RESUMO

Human filariasis due to Loa loa differs from other filariasis in that the majority of infected subjects are without circulating microfilariae (occult loiasis). In search for alternative diagnostic methods, which do not depend on circulating microfilariae or the (rather infrequent) eye-passage of adult worms, it was shown earlier that IgG4 antibodies directed against Loa loa adult worm antigen are apparently a good marker of occult loiasis and specific with regard to the sympatrically occurring Mansonella perstans. In this study we evaluated an IgG4 antibody-based ELISA using crude extract of Loa loa microfilariae (which is easier to obtain than adult worm) to estimate the prevalence of loiasis in 3 villages in South-East Gabon. Of 222 examined individuals (80 children < 16 years, 142 adults) 44 (20%) carried Loa loa microfilariae and 170 (77%) M. perstans. Using the mean OD-value + 1 standard deviation of 9 sera from patients solely infected with M. perstans (from the Gambia, where Loa loa is not endemic) as a cut-off, 35 of the 44 microfilaraemic Loa loa patients and 2 of the 9 Gambian controls were positive. This shows that our method had a sensitivity of 80% and a specificity of 78%. Among the remaining 178 subjects who had no microfilariae of Loa loa, as many as 97 (55%) had significant levels of specific IgG4 antibodies against Loa loa, suggesting that they carried occult loiasis. The mean IgG4 level in these putatively occult loiasis patients was slightly but significantly lower than in microfilaraemic subjects (P < 0.03). In conclusion, despite the limited sensitivity and specificity of our method, IgG4- ELISA at present is a very useful tool in estimating the real prevalence of loiasis in epidemiological surveys and at the individual level can confirm the diagnosis of L. loa amicrofilaraemic subjects with clinical signs suggesting loiasis.


Assuntos
Anticorpos Anti-Helmínticos/sangue , Imunoglobulina G/sangue , Loa/imunologia , Loíase/epidemiologia , Adolescente , Adulto , Animais , Formação de Anticorpos , Antígenos de Helmintos/imunologia , Criança , Ensaio de Imunoadsorção Enzimática , Feminino , Gabão/epidemiologia , Humanos , Loíase/diagnóstico , Masculino , Prevalência , Sensibilidade e Especificidade , Estudos Soroepidemiológicos
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