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Biomedical subjects

F J Louis

Publications and source records attributed to F J Louis.

At least 19 recordsLinked to original sources
PubMed2006

The elimination of Trypanosoma brucei gambiense sleeping sickness in the focus of Luba, Bioko Island, Equatorial Guinea.

After the resurgence of sleeping sickness in Luba, Equatorial Guinea, a major campaign to control the disease was established in 1985. The campaign comprised no vector control, but intensive active and passive surveillance using serology for screening, and treatment of all parasitological and suspected serological cases. Total prevalence was used to classify villages as endemic, at risk, anecdotal and non-endemic which also allowed defining the geographic extent of the focus. Active case-finding was implemented from 1985 to 2004. The frequency of surveys was based on parasitological prevalence: twice a year during intensified control, once a year during ordinary control and once every 2 years during the control consolidation phase, when the parasitological prevalence in the whole focus fell to 0.1%. From 1985 to 1999, the indirect immunofluorescent antibody test (IFAT) was used as an initial screening tool, followed by parasitological confirmation of IFAT positive cases, and the Card Agglutination Trypanosomiasis Test (CATT) if necessary. In 2000, the IFAT was replaced by the CATT. Serum-positive individuals without parasitological confirmation were subsequently tested on serial dilution. All cases underwent lumbar puncture to determine the stage of the disease. First-stage cases were treated with pentamidine and second-stage cases with melarsoprol. A few relapses and very advanced cases were treated with eflornithine. The last sleeping sickness case was identified and treated in 1995.

Agglutination Tests↗
PubMed2003

[The concept of neglected disease].

"Neglected disease", "neglected population" and more generally "public health negligence" are emerging concepts being put forward by numerous humanitarian groups. Sleeping sickness provides a typical example to illustrate these concepts. After causing a major epidemic in the 1930s, sleeping sickness had been practically eradicated by the end of decolonization. Because of more urgent priorities, independent national governments relinquished control activities thus allowing the disease to return insidiously. By the beginning of the 1990s the situation was comparable to that prevailing in 1930 without inciting a response commensurate with the extent of the problem. Sleeping sickness is currently not a priority and, more simply, is not given proper attention because it affects only a few people living in regions presenting little economic interest. This point underlines the especially devastating combination of neglected disease and neglected population. As early as 1999 the World Health Organization with the determined support of Medecins Sans Frontieres launched a campaign not only to promote control measures for sleeping sickness at the international level but also to use initiatives in the domain to illustrate the enormous potential for progress against neglected disease. The effects of this campaign are now beginning to be felt.

Africa↗
PubMed2003

[Status of sleeping sickness in 2003].

On May 3, 2001, the World Health Organization signed a major agreement with the pharmaceutical industry for the supply of drugs necessary for treatment of sleeping sickness. At that time Dr. Gro Harlem Brutland, director of the WHO, announced, "We can now look forward to halting the spread of sleeping sickness...". The purpose of this article is to take a look at the situation two years later. A first assessment showed that most national programs for the control of human African trypanosomiasis (NPCHAT) had practically become inoperative. One of the first steps in the new eradication campaign consisted of reviving these NPCHAT teams. However this goal could be achieved only insofar as awareness of the severity of the disease and of the need to act was felt at every level of decision-making. In 2001 the Pan-African Tse-Tse Trypanosomiasis Eradication Campaign (PATTEC) initiative was launched by African State leaders to promote special attention at the ministerial level, high-level training, and international cooperation sometimes involving several NPCHAT teams. Actions in the field include trials using new strategies, expert assistance for personnel throughout the duration of prospection, and screening and immediate treatment of numerous patients in outbreak areas where the disease was thought to be extinct. Although progress has not always been measurable in concrete terms, the dynamics have shifted almost everywhere.

Africa↗
PubMed2003

[Sleeping sickness, forgotten illness: what are the consequences in the field?].

For nearly 25 years, sleeping sickness was forgotten and increasingly neglected. Research programs and control activities against human African trypanosomiasis were discontinued. Statistical studies show a constant decrease in the number of people screened and cases detected and little change in the ratios of actively versus passively diagnosed cases and of the early (blood and lymph involvement) versus late (cerebral involvement) stage cases. In the field neglect of the disease led to deterioration not only physical facilities but also human resources. As teams aged, senior members were often replaced by less than fully qualified people resulting in a decline in efficiency and organization. Many basic notions were lost and the albeit scarce innovations in diagnosis and therapy were often overlooked. When the fight against sleeping sickness was finally resumed, these factors had to be taken into account. Efforts in the field have been focused on four areas: renovation of equipment, didactic and practical training for health care personnel, development of a decision-making algorithm based on diagnostic findings, and implementation of new therapeutic protocols.

Algorithms↗
PubMed2003

[Human African trypanosomiasis in an urban area: an emerging problem?].

The human African trypanosomiasis is essentially a rural disease. The notification of cases in urban area has always been incidental; either a diagnosis made in town revealed a disease contracted in rural environment or it meant the preservation of a complete epidemiological cycle in a remaining urban micro-focus. In Kinshasa, in Democratic Republic of Congo, about forty cases have been notified each year. All of them came from the nearby foci of Bandundu, Lower Congo and Kasaï. In 1996 the number of cases reached suddenly 254 and today the average annual number comes up to 500 in spite of all the efforts undertaken to fight the disease. A study of cases in 1998 and 1999 shows that patients are essentially distributed in suburbs and that the most affected by the disease are the 15-49 year old ones whose job is related with agricultural or fishing activities. Two phenomena seem to explain this sudden increase: the massive inflow of refugees in outskirts of town coming from provinces where trypanosomiasis is endemic and a major economic crisis throwing out urban population in suburbs living on a subsistence micro-agriculture. These concomitant factors have contributed to the setting up of a trypanosomiasis belt around the capital. Today a strategy has to be reconsidered in order to fight against the disease in the capital itself and to make the medical staff aware of the diagnosis of a disease still unknown in their sanitary district.

Adolescent↗
PubMed2002

[Sleeping sickness: one hundred years of control strategy evolution].

Sleeping sickness has been known since the fifteenth century but the real progress in the knowledge of the disease occurred in the nineteenth century with the development of microscopy. From 1841 to 1901 the parasites and their vectors have been identified, the symptomatology and the epidemiology have been described. However, due to absence of any effective cure, the campaign against the disease was still based on the isolation of the patients and the transfer of exposed populations. The discovery of atoxyl in 1905 provided doctors with their first therapeutic weapon and, in 1910, the first action of vector control was undertaken with success in the Island of Principe. Between the two world conflicts, Jamot published the rules to fight against major outbreaks. Their application in Oubangui-Chari, in Cameroon and in French Occidental Africa brought tremendous results and signed the triumph of the mobile unit concept. Success which will not be denied until the sixties when the disease was believed to be eradicated. From the sixties to the nineties, the concept of the integration of prevention and care added to the exclusion of any vertical system will result in a progressive reniewed outbreak of the sleeping sickness in the known foci. As a paradox, it is a time rich in discovery as regards diagnosis, treatment and entomology. In 1994, the World Health Organisation got concerned with the situation of the disease in Central Africa where the outbreak of the disease reinforced. A second paradox appeared; it is the next to total disinterest from the politics and fund raisers which will save the disease. Today, sleeping sickness is the typical example of the orphan disease, a show case brandished by all the good souls. In 2001, an agreement between the WHO and the pharmaceutical industry brings back the financial funds required to fight the disease. Basically, it is a matter of resuming the action by using what is still existing and by creating new strategies considering the extreme lack of human and logistical resources. The objective is to eradicate the sleeping sickness as a public health problem. The challenge is huge, but is on the way to success.

Africa↗
PubMed2001

[Diagnosis of human African trypanosomiasis in 2001].

Human African trypanosomiasis is characterized by a non-specific clinical presentation with no consistent, pathognomonic manifestations. However definite diagnosis is necessary to avoid unnecessary therapeutic risks with toxic drugs. Further complicating this situation is the frequent need to achieve field diagnosis in remote locations with limited facilities. Serological tests such as CATT (card agglutination trypanosomiasis test) are useful for initial population screening to identify suspects but are not sufficiently reliable for definitive diagnosis since the variations in sensitivity and specificity have been observed between countries and disease pockets. Parasitological examination is still the only method of definitive diagnosis. Thresholds of trypanosome detection differ from one technique to another, i.e., 10,000 trypanosomes per millilitre (T/ml) for fresh blood smears, 5,000 T/ml for thick drop specimens stained with Giemsa, 500 T/ml for centrifugation in capillary tubes, less than 500 T/ml for the QBC test, and 100 T/ml for the ion exchange minicolumn system. The possibility that the QBC test and minicolumn anion exchange system may go out of production could pose a serious problem for field diagnosis. Decisional algorithms are being developed to optimize use of remaining techniques.

Animals↗
PubMed2001

[Technical reasons for the re-emergence of sleeping sickness].

In the 1920s the epidemic outbreak of human African trypanosomiasis was so deadly that government authorities decided to take large-scale action. It was by giving Jamot absolute administrative and financial autonomy to apply his ideas that the disease was successfully controlled. After Jamot determined efforts against the disease continued so that, by the dawn of decolonization, many considered the problem of sleeping sickness as resolved. Control programs progressively slowed and virtually ceased. Neglected and all but forgotten, the disease has able to make a natural and forceful comeback. Obvious attempts have been made to explain this comeback in terms of poor commitment on the part of health authorities, disappearance of competent work groups, and lack of money and personnel. True as these issues may be, it is just not that simple. Many other problems prevent disease management from being delegated to primary healthcare workers including the difficulty of clinical, serological, and parasitological diagnosis, inability to implement effective widespread vector control, paucity of therapeutic modalities, and irrationality of vaccination. Under these conditions, re-emergence of the disease was unavoidable and future control efforts will be difficult.

Africa↗
PubMed2001

[Control of human African trypanosomiasis: back to square one].

The natural history of sleeping sickness is cyclic. The first epidemic outbreak in the 19th century devastated the population and resolved spontaneously for lack of victims. Intensive development during the colonial period and the movement of population that it spawned led to another epidemic in the early 1920s that reached such severe proportions that drastic steps had to be taken. At that time, Jamot was given complete political, administrative, and financial freedom to combat the disease. This program led to the development of the mobile team concept and so-called vertically structured vector control strategy and was so successful that sleeping sickness ceased to be considered as a major public health problem at the beginning of the 1960s. In the ensuing years sleeping sickness was largely neglected. Monitoring the disease required specialized teams that were no longer considered as cost-effective. One by one the measures that had been implemented to control the disease disappeared, thus setting the scene for a new outbreak grew. In 1995, the incidence of sleeping sickness reached the same levels as in the 1920s. The current situation is a classic example of a neglected disease with a paucity of competent specialists, diagnostic tests, effective drugs, and operational facilities. It was not until 2001 that new hope appeared thanks to a combined public- and private-sector initiative allowing restructuring of treatment teams, renovation of facilities, free distribution of drugs, and research to develop new therapeutic agents. Also thanks to the PATTEC initiative, the governments of the African affected nations are showing new in interest in sleeping sickness. However the battle is far from won and much effort will be required. Time is running out and the stakes are high.

Africa↗
PubMed2001

[Human African trypanosomiasis in the urban milieu: the example of Kinshasa, Democratic Republic if the Congo, in 1998 and 1999].

Human African trypanosomiasis is an essentially rural disease. Occurrence in urban areas is uncommon except in cities that reproduce rural conditions conducive to the survival of glossinidae, i.e., forest and water. This is the case in neighborhoods near the zoo in Brazzaville, People's Republic of the Congo and in the residual mangrove forest in Conakry, Guinea. In Kinshasa, Democratic Republic of the Congo, an average of 39 cases were reported annually from 1970 to 1995. This figure increased to 254 in 1996 and 226 in 1997. This sharp rise led authorities to organize screening operations in some neighborhoods of the capital city. Results documented 433 cases in 1998 and 912 cases in 1999. The highest prevalence was found in outlying areas. This finding was probably related to focus of screening in these locations and to the practice of market gardening on plots surrounding the city. Placement of 276 insect traps along the Ndjili River led to the capture of 42,231 glossinidae over a 4 month period. Taken together, these findings indicate that the conditions necessary for active disease transmission are now reunited and that priority should be given to intensifying screening operations and information campaigns to health care providers working in the city.

Adolescent↗
PubMed1999

Evaluation of the monocyte counting by the ABX Vega. Comparison with the manual method and fluoro-flow cytometry.

This study allowed evaluation and comparison of the precision (20 samples) and agreement (200 samples) of the relative and absolute values of the monocyte count using three methods: microscopic, flow cytometry and the automated ABX Vega hematology analyzer. Flow cytometry is the most precise method, even if the coefficient of variation of the automated analyzer is very similar. The coefficient of correlation between the ABX Vega and the flow cytometer is very satisfactory (r=0.8042). This study of the agreement also made it possible to confirm the difficulty that automated hematology analyzers have in differentiating between some granulocytes and monocytes and their propensity to overstimate the latter when the sample includes immature forms of granulocytes. This fact stresses the importance of the microscopic method, despite its lack of precision. The observed discrepancies did not lead to any difficulties in clinical interpretation; however, this finding should be taken into consideration, particularly in myleoproliferative syndromes and the laboratory monitoring of chemotherapy.

Flow Cytometry↗
PubMed1999

[Comparative study of artemether and quinine in severe Plasmodium falciparum malaria in adults and older children in Cameroon].

From June 1993 to June 1994, a study was carried out to compare artemether and quinine for management of severe falciparum malaria in adults and adolescents in Cameroon. Artemether was administered intramuscularly at a dose of 3.6 mg/kg on the first day and 1.6 mg/kg for the following 4 days. Quinine was administered intravenously at a dose of 1.6 mg/kg for the first 4 hours and 8 mg every 8 hours for the next 3 days. The files of 84 of the 95 patients recruited were validated for inclusion in the final study. There were 40 patients in the artemether group and 44 in the quinine group. The two groups were comparable with regard to all factors at the time of inclusion. Findings showed that artemether was more effective than quinine with regard to total clearance of parasitemia, 90 p. 100 clearance, and fever control and that it was as effective with regard to 50 p. 100 clearance and recovery of consciousness. In view of its good performance and of the simplicity of its administration by intramuscular injection, artemether would appear to be an excellent alternative for treatment of severe malaria and cerebral malaria in areas with poor medical facilities.

Adolescent↗