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Biomedical subjects

D Legros

Publications and source records attributed to D Legros.

At least 19 recordsLinked to original sources
PubMed2006

Two clusters of human infection with influenza A/H5N1 virus in the Republic of Azerbaijan, February-March 2006.

Following the appearance of influenza A/H5 virus infection in several wild and domestic bird species in the Republic of Azerbaijan in February 2006, two clusters of potential human avian influenza due to A/H5N1 (HAI) cases were detected and reported by the Ministry of Health (MoH) to the World Health Organization (WHO) Regional Office for Europe during the first two weeks of March 2006. On 15 March 2006, WHO led an international team, including infection control, clinical management, epidemiology, laboratory, and communications experts, to support the MoH in investigation and response activities. As a result of active surveillance, 22 individuals, including six deaths, were evaluated for HAI and associated risk infections in six districts. The investigations revealed eight cases with influenza A/H5N1 virus infection confirmed by a WHO Collaborating Centre for Influenza and one probable case for which samples were not available. The cases were in two unrelated clusters in Salyan (seven laboratory confirmed cases, including four deaths) and Tarter districts (one confirmed case and one probable case, both fatal). Close contact with and de-feathering of infected wild swans was considered to be the most plausible source of exposure to influenza A/H5N1 virus in the Salyan cluster, although difficulties in eliciting information were encountered during the investigation, because of the illegality of some of the activities that might have led to the exposures (hunting and trading in wild birds and their products). These cases constitute the first outbreak worldwide where wild birds were the most likely source of influenza A/H5N1 virus infection in humans. The rapid mobilisation of resources to contain the spread of influenza A/H5 in the two districts was achieved through collaboration between the MoH, WHO and its international partners. Control activities were supported by the establishment of a field laboratory with real-time polymerase chain reaction (RT-PCR) capacity to detect influenza A/H5 virus. Daily door-to-door surveillance undertaken in the two affected districts made it unlikely that human cases of influenza A/H5N1 virus infection remained undetected.

Azerbaijan↗
PubMed2006

[Detection of anti-Lassa antibodies in the Western Forest area of the Ivory Coast].

Lassa fever is an African viral hemorrhagic fever (VHF) known to be endemic in a number of West African countries including Nigeria, Sierra Leone, Liberia and Guinea. Despite having common borders with Liberia and Guinea, Côte d'Ivoire has never reported any cases of Lassa fever. In March 2000, as part of a research project on VHF--mainly yellow fever, Lassa fever and Ebola fever--in Guinea and Cote d'Ivoire, an exploratory survey was conducted to assess knowledge about VHF and immunological status against Lassa virus among forest workers in the Duekoue and Guiglo regions. One hundred and sixty-three male forest workers were interviewed using a questionnaire designed to assess risk factors for VHF exposure and personal medical history over the last 12 months. Detection of IgG antibodies against Lassa virus was performed by immunofluorescence assay with Lassa virus antigens from the Josiah and Las/AV strains. The overall prevalence of IgG antibodies was 26% (42/161). Among the Lassa IgG positive subjects, 38.5% were loggers including 20% that were positive at a serum dilution of 1/40 and 46.7% were national park workers or forest rangers including 69% that were positive at a dilution of 1/40 and more. Forty-one percent of subjects had heard of VHF including 14% who attributed it to animals and 2% who attributed it to plants. Contact with rodents was frequent and more than 50% of subjects had either eaten or skinned rodents. Although the prevalence of anti-Lassa IgG antibodies seemed high in the study population, no conclusion can be about level of exposure to Lassa virus.

Adult↗
PubMed2004

Case management of a multidrug-resistant Shigella dysenteriae serotype 1 outbreak in a crisis context in Sierra Leone, 1999-2000.

From December 1999 to the end of February 2000, 4218 cases of dysentery were reported in Kenema district, southeastern Sierra Leone, by a Médecins Sans Frontières team operating in this region. Shigella dysenteriae serotype 1 was isolated from the early cases. The overall attack rate was 7.5% but higher among children under 5 years (11.2%) compared to the rest of the population (6.8%) (RR = 1.6; 95% CI 1.5-1.8). The case fatality ratio was 3.1%, and higher for children under 5 years (6.1% vs. 2.1%) (RR = 2.9; 95% CI 2.1-4.1). A case management strategy based on stratification of affected cases was chosen in this resource-poor setting. Patients considered at higher risk of death were treated with a 5 day ciprofloxacin regimen in isolation centres. Five hundred and eighty-three cases were treated with a case fatality ratio of 0.9%. Patients who did not have signs of severity when seen by health workers were given hygiene advice and oral rehydration salts. This strategy was effective in this complex emergency.

Adolescent↗
PubMed2002

IgM quantification in the cerebrospinal fluid of sleeping sickness patients by a latex card agglutination test.

An increased IgM concentration in cerebrospinal fluid (CSF), occurring as a consequence of massive intrathecal IgM synthesis, is a marker of interest for diagnosis of the meningo-encephalitic stage in human African trypanosomiasis. However, in current practice, IgM in CSF is not determined because of the lack of a simple and robust test that is applicable in African rural regions where the disease prevails. We describe the development of a sensitive semiquantitative card agglutination test, LATEX/IgM, for IgM quantification in CSF. The test is simple and fast and the lyophilized reagent remains stable even at 45 degrees C. CSF end-titres obtained with LATEX/IgM parallel the IgM concentrations determined by nephelometry and enzyme-linked immunosorbent assay. Detection of intrathecal IgM synthesis is the most sensitive marker for CNS involvement in sleeping sickness. At a cut-off value of >or= 8, the sensitivity and specificity of LATEX/IgM for intrathecal IgM synthesis are 89.4 and 92.7%. As a consequence, patients with LATEX/IgM end-titres >or= 8 are likely to have intrathecal IgM synthesis, thus central nervous system involvement and therefore should be treated accordingly. Further studies should concentrate on the relationship between the LATEX/IgM end-titres, presence of intrathecal IgM synthesis and occurrence of treatment failures in patients treated with pentamidine.

Animals↗
PubMed2002

In vitro susceptibility of 120 strains of Neisseria gonorrhoeae isolated in Kyrghyzstan.

BACKGROUND: The World Health Organization has established a worldwide program for gonococcal antimicrobial surveillance, but so far no data on gonococcal susceptibility in Central Asia are available. GOAL: The need for biological data on the susceptibility of Neisseria gonorrhoeae in Kyrghyzstan, to enable adaptation of the national treatment protocol for gonococcal infections, led Médecins Sans Frontières and Epicentre to conduct a survey in collaboration with the Alfred Fournier Institute in Paris and the health authorities in Bishkek. STUDY DESIGN: In vitro susceptibility of N gonorrhoeae strains was determined with use of the reference agar-plate dilution technique. RESULTS: Results for 11 antibiotics tested on 120 strains of gonococci showed a low proportion (11.7%) of penicillinase-producing N gonorrhoeae and high proportions of intermediate or resistant strains to the majority of the antibiotics tested, including fluoroquinolones (>or=25% of strains resistant). All the strains were susceptible to spectinomycin, and only two strains had decreased susceptibility to cefixime. CONCLUSION: The therapeutic choices available in Kyrghyzstan appear to be limited to cephalosporins and spectinomycin.

Anti-Bacterial Agents↗
PubMed2002

The efficacy of chloroquine for the treatment of acute, uncomplicated, Plasmodium falciparum malaria in Laos.

To assess the local efficacy of chloroquine for the treatment of acute, uncomplicated, Plasmodium falciparum malaria, children and adults from Sekong province (an area of Laos with a low intensity of transmission) were tested in a 28-day, in-vivo study. Complete data were collected from 88 of the 102 subjects enrolled between October 1999 and September 2000. After genotypic analysis to distinguish recrudescing infections from re-infections, 35 (39.7%, with a 95% confidence interval of 29.5%-50.7%) of these 88 patients were considered treatment failures. These results seriously question the use of chloroquine as the first-line treatment for P. falciparum malaria in the study area.

Acute Disease↗
PubMed2002

[Impact of war on civilian population health. Republic of the Congo, December 1998-February 2000].

Congo Brazzaville was racked by civil war between 1998 and 2000. Fighting forced a large part of the population to flee from the capital, Brazzaville. Starting in 1999 many people began coming back to the city in dire physical and psychological condition. With little or no press coverage, this return went largely unnoticed by the general public. Volunteers from Médecins Sans Frontières were present not only to provide assistance and care to these war victims but also as to bear witness so that this tragedy should not be forgotten. By means of epidemiological surveys in the field, workers were able to paint a "picture of suffering" and to document the violence and deprivation inflicted mainly on the civilian population. This article summarizes the findings of this investigation.

Adult↗
PubMed2002

[Management of cholera epidemics in a refugee camp].

Cholera epidemics in refugee camps represent a major public health emergency. In camps, precarious living conditions contribute to the transmission of the vibrio. Among the major epidemics reported in camps, we note as well those which have affected Africa in the last two decades. These epidemics are characterized by high attack rates and high case fatality ratios. Attack rates in refugee camps can exceed 5%. Appropriate control measures are adopted at international level. Actions carried out urgently must allow the proper supply of water, the control of excreta, and the improvement of general sanitary conditions and individual hygiene. Efficient management of cases in specialized cholera treatment centres (CTC) should decrease the case fatality ratio to less than 1%. Treatment is mainly based on the prompt rehydration of patients. For wide camps, rapid access to oral rehydration units is essential. Availability of all necessary equipment in kit form is required.

Cholera↗
PubMed2001

Melarsoprol refractory T. b. gambiense from Omugo, north-western Uganda.

Culture adapted T. b. gambiense isolated from Northwest Uganda were exposed to 0.001-0.14 microg/ml melarsoprol or 1.56-100 microg/ml DL-alpha-difluoromethylornithine (DFMO). Minimum inhibitory concentrations (MICs) of each drug were scored for each isolate after a period of 10 days drug exposure. The results indicate that T. b. gambiense isolates from Northwest Uganda had elevated MIC values for melarsoprol ranging from 0.009 to 0.072 microg/ml as compared with T. b. gambiense isolates from Cote d'Ivoire with MIC values ranging from 0.001 to 0.018 microg/ml or with T. b. rhodesiense from Southeast Uganda with MIC values from 0.001 to 0.009 microg/ml. All MIC values obtained fell below expected peak melarsoprol concentrations in serum of treated patients. However, it may not be possible to maintain constant drug concentrations in serum of patients as was the case in our in vitro experiments. Importantly, the MIC of 0.072 microg/ml exhibited by one of the isolates from Northwest Uganda was above levels attainable in CSF indicating that this isolate would probably not be eliminated from CSF of treated patients. PCR amplification of the gene encoding the P2-like adenosine transporter followed by restriction digestion with Sfa NI enzyme revealed presence of fragments previously observed in a trypanosome clone with laboratory-induced arsenic resistance. From our findings it appears that reduced drug susceptibility may be one factor for the frequent relapses of sleeping sickness after melarsoprol treatment occurring in Northwest Uganda.

Animals↗
PubMed2001

Availability and affordability of treatment for Human African Trypanosomiasis.

Human African Trypanosomiasis (HAT) is a re-emerging disease whose usual treatments are becoming less efficient because of the increasing parasite resistance. Availability of HAT drugs is poor and their production in danger because of technical, ecological and economic constraints. In view of this dramatic situation, a network involving experts from NGOs, WHO and pharmaceutical producers was commissioned with updating estimates of need for each HAT drug for the coming years; negotiations with potential producers of new drugs such as eflornithine; securing sustainable manufacturing of existing drugs; clinical research into new combinations of these drugs for first and second-line treatments; centralizing drug purchases and their distribution through a unique non-profit entity; and addressing regulatory and legal issues concerning new drugs.

Eflornithine↗
PubMed2001

Rapid assessment of population size by area sampling in disaster situations.

In the initial phase of a complex emergency, an immediate population size assessment method, based on area sampling, is vital to provide relief workers with a rapid population estimate in refugee camps. In the past decade, the method has been progressively improved; six examples are presented in this paper and questions raised about its statistical validity as well as important issues for further research. There are two stages. The first is to map the camp by registering all of its co-ordinates. In the second stage, the total camp population is estimated by counting the population living in a limited number of square blocks of known surface area, and by extrapolating average population calculated per block to the total camp surface. In six camps selected in Asia and Africa, between 1992 and 1994, population figures were estimated within one to two days. After measuring all external limits, surfaces were calculated and ranged between 121,300 and 2,770,000 square metres. In five camps, the mean average population per square was obtained using blocks 25 by 25 meters (625 m2), and for another camp with blocks 100 by 100 m2. In three camps, different population density zones were defined. Total camp populations obtained were 16,800 to 113,600. Although this method is a valuable public health tool in emergency situations, it has several limitations. Issues related to population density and number and size of blocks to be selected require further research for the method to be better validated.

Africa↗
PubMed2001

Biological data and clinical symptoms as predictors of astrogliosis and neurodegeneration in patients with second-stage Trypanosoma brucei gambiense sleeping sickness.

Concentrations of glial fibrillary acidic protein (GFAp) and light subunit neurofilament protein (NFL) in cerebrospinal fluid (CSF) were measured in patients with second-stage Trypanosoma brucei gambiense sleeping sickness. Correlations between GFAp and NFL in CSF as markers for astrogliosis and neurodegeneration, and clinical and biological data were investigated. Abnormal levels of GFAp and NFL were significantly associated with increasing CSF cell number and protein concentration, and with the absence of lymph nodes or the absence of trypanosomes in lymph node aspirate. A significant association was found between abnormal NFL and presence of trypanosomes in CSF, abnormal limb movements, difficulties in gait and coordination, and low Karnofsky index. By multivariate analysis, it was shown that increasing CSF cell number, increasing CSF protein concentration, and the absence of lymph nodes or the absence of trypanosomes in the lymph node aspirate were the best predictors for astrogliosis and neurodegeneration among the variables tested. These results demonstrate the importance of CSF cell count and protein determination in assessment of the severity of central nervous system involvement and reinforces the importance of laboratory diagnosis to assess the stage of the disease. The clinical symptoms studied were less useful in predicting astrogliosis or neurodegeneration.

Adolescent↗
PubMed2000

Epidemiology of cholera outbreak in Kampala, Uganda.

OBJECTIVE: To provide epidemiological description of the cholera outbreak which occurred in Kampala between December 1997 and March 1998. DESIGN: A four-month cross-sectional survey. SETTING: Kampala city, Uganda. MAIN OUTCOME MEASURES: Number of cases reported per day, attack rate per age group and per parish, case fatality ratio. RESULTS: The cholera outbreak was due to Vibrio cholerae O1 El Tor, serotype Ogawa. Between December 1997 and March 1998, 6228 cases of cholera were reported, of which 1091 (17.5%) were children under five years of age. The overall attack rate was 0.62%, similar in the under-fives and five and above age groups. The case fatality ratio among hospitalised patients was 2.5%. The peak of the outbreak was observed three weeks after the report of the first case, and by the end of January 1998 (less than two months after the first case), 88.4% of the cases had already been reported. The occurrence of cases concentrated in the slums where the overcrowding and the environmental conditions resembled a refugee camp situation. CONCLUSION: The explosive development of the cholera outbreak in Kampala, followed by a rapid decrease of the number of cases reported is unusual in a large urban setting. It appeared that each of the affected slums developed a distinct outbreak in a non immune population, which did not spread to contiguous areas. Therefore, we believe that, a decentralised strategy, that would focus the interventions on each heavily affected area, should be considered in these circumstances.

Adolescent↗