Biomedical subjects

M Koffi

Publications and source records attributed to M Koffi.

8 recordsLinked to original sources

PubMed2006

Cyclical transmission of Trypanosoma brucei gambiense in Glossina palpalis gambiensis displays great differences among field isolates.

Six sets of teneral Glossina palpalis gambiensis (Diptera: Glossinidae) were fed on mice infected with six different isolates of Trypanosoma brucei gambiense (each mouse was infected with one of the isolates), previously isolated from patients in the sleeping sickness focus of Bonon, Côte d'Ivoire and in Makoua, Congo. All the tsetse flies were dissected 42 days post-infection and midgut and salivary glands were examined for trypanosomes by microscopical examination. No infection was observed with the reference stock whereas each of the five recently isolated trypanosome isolates was able to infect tsetse flies, with rates of infection varying between 9.7 and 18.2% depending on the isolate. Three isolates displayed only immature infections with 9.7, 17.3 and 18% of the flies showing trypanosomes in their midgut. One isolate gave both immature (12.1%) and mature infections (6.1%). Finally, the last isolate involved only mature infections in 9.7% of the Glossina species examined. These substantial differences in the cyclical transmission of T. b. gambiense in the same fly species could have important implications for the epidemiology of the transmission of Human African Trypanosomiasis.

Animals↗

PubMed2006

Aparasitemic serological suspects in Trypanosoma brucei gambiense human African trypanosomiasis: a potential human reservoir of parasites?

The serological and parasitological tests used for Trypanosoma brucei gambiense human African trypanosomiasis (HAT) diagnosis have low specificity and sensitivity, respectively, and in the field, control program teams are faced with subjects with positive serology but negative parasitology who remain untreated. The aim of this work was to explore, using PCR tool, the significance of these aparasitemic serological suspects. Since discordant PCR results have been observed earlier with different extraction methods, two DNA extraction methods were compared (the Chelex 100 resin and the DNeasy Tissue kit). The study was conducted on 604 blood samples: 574 from parasitologically confirmed patients, aparasitemic serological suspects and endemic controls collected in Côte d'Ivoire and 30 from healthy volunteers collected in France. No significant differences were observed between the PCR results obtained with the two extraction methods. Concerning PCR, problems of reproducibility and discordances with both serological and parasitological test results were observed, mainly for the aparasitemic serological suspects. In addition to previous results that pointed to the existence of non-virulent or non-pathogenic trypanosome strains and of individual susceptibility leading to long term seropositivity without detectable parasitaemia but positive PCR, the results of this study support the notion of a long lasting human reservoir that may contribute to the maintenance or periodic resurgences of HAT in endemic foci.

Agglutination Tests↗

PubMed2006

[The impact of war on the evolution of sleeping sickness in west-central Côte d'Ivoire].

OBJECTIVE: To evaluate the situation of sleeping sickness in west-central Côte d'Ivoire from 2000 to 2003, in view of the war which broke out in September 2002. METHODS: Active surveys by medical teams and passive case detection. RESULTS: Between 2000 and 2003, 250 patients were diagnosed with sleeping sickness. At first it appeared that sleeping sickness prevalence had fallen since the beginning of political troubles. But this apparent drop was due to poor population coverage. Participation in medical surveys differed according to ethnic group, reflecting land use conflicts between ethnic communities. Such conflicts are common in this area, but have been exacerbated by the war. CONCLUSION: In war, assessing the importance of sleeping sickness by medical surveys only is very difficult. But detection of sleeping sickness cases by passive surveillance increased.

Conflict, Psychological↗

PubMed2004

Mixed infections of trypanosomes in tsetse and pigs and their epidemiological significance in a sleeping sickness focus of Côte d'Ivoire.

In a sleeping sickness focus of Côte d'Ivoire, trypanosomes were characterized in humans, pigs and tsetse using various techniques. Out of 74 patients, all the 43 stocks isolated by KIVI (Kit for In Vitro Isolation) appeared to belong to only one zymodeme of Trypanosoma brucei gambiense group 1 (the major zymodeme Z3). The only stock isolated on rodents belonged to a different, new, zymodeme (Z50), of T. b. gambiense group 1. From 18 pigs sampled in the same locations as the patients, PCR showed a high proportion of mixed infections of T. brucei s. l. and T. congolense riverine-forest. Zymodemes of T. brucei s. l. from these pigs were different from those found in humans. From a total of 16 260 captured tsetse (Glossina palpalis palpalis), 1701 were dissected and 28% were found to be infected by trypanosomes. The most prevalent trypanosome was T. congolense riverine-forest type, followed by T. vivax, T. bruceis. l. and T. congolense savannah type, this latter being associated to the forest type of T. congolense in most cases. Mixed infections by 2 or 3 of these trypanosomes were also found. Use of a microsatellite marker allowed us to distinguish T. b. gambiense group 1 in some of the mature infections in tsetse. Differences in infection rates and in trypanosome genotypes according to the host might indicate that the pig may not be an active animal reservoir for humans in this focus.

Animals↗

PubMed2004

Characterization of Trypanosoma brucei s.l. infecting asymptomatic sleeping-sickness patients in Côte d'Ivoire: a new genetic group?

Six villagers in the Sinfra focus of sleeping sickness in Côte d'Ivoire who in 1995 were asymptomatic and refusing treatment, despite then being serologically and parasitologically positive for trypanosomes, were followed-up, while still refusing treatment, until 2002. In 2002, five of the six cases remained serologically positive but no trypanosomes could be found in any of them by use of the classical parasitological methods. A PCR-based assay, however, revealed that all six had the DNA of Trypanosoma brucei s.l. in their blood, so confirming the low sensitivity of the classical parasitological tests. The analysis of satellite, minisatellite and microsatellite markers indicated that, in 2002, all six cases were infected with a 'new' distinct genetic group of T. brucei s.l. and four were co-infected with T. b. gambiense group 1. The epidemiological consequences of such co-infections are discussed. The 'new' group of T. brucei had a molecular pattern that differed from those of the classical T. b. gambiense group 1 and the 'bouaflé' group.

Animals↗

PubMed1999

[Profile of leprosy in the Sanitary District of Odienné, North-West region of the Ivory Coast].

To determine the characteristics of leprosy in the Sanitary District of Odienné in the North Western part of Ivory Coast, a retrospective study was made based on patients of four years. This study showed that 107 lepers were detected from 1994 to 1997 and all of them benefited from polychemotherapy. Leprosy affected youngsters as well as adults (aged 4 to 95) with a slight feminine prevalence (55%). Patients were detected and put on polychemotherapy about 5 years after the first symptoms had appeared. The paucibacillaries represented 72.5% and were most present with women. Disabilities at detection were of 25.7% on the whole with a higher frequency in the multibacillary group (43.3%) than in the paucibacillary (19%); moreover, level 2 disabilities represented 10.1%, most of them being confined on hands. Finally, the efforts of sensibilisation seem having given the opportunity to the majority of patients detected in 1997 to come spontaneously for consultation, just after the first signs of illness. This sensibilisation has to be sustained.

Adolescent↗

PubMed1999

[Management strategies for endemic goiter in developing countries].

Despite significant progress in the last decades, endemic goiter remains a serious public health problem in the developing world, especially in Africa. Even in countries that have successfully reduced overall incidence to acceptable levels, endemic areas often remain. This persistence is due to the inadequacy of preventive measures and poor follow-up of control programs. The main etiologic factor in endemic goiter is inadequate dietary intake of iodine. This commonly occurs in communities depending exclusively on local produce grown on iodine-poor land, especially in mountain areas. Endemic goiter is epidemiologically associated with cretinism, deaf-mutism, and mental retardation. Even mild iodine deficiency leads to clinical hypothyroidism and moderate myxoedema with significantly reduced intellectual performance. Prevention of endemic goiter depends mainly on increasing the iodine intake of people in endemic areas. When iodine intake reaches the estimated adult minimum requirement (100 to 150 micrograms per day), the prevalence of goiter decreases. Two approaches have been used to increase iodine intake. The first consists of adding iodine to food staples such as table salt. The second consists of medical treatment using agents such as iodized oil. Iodization or iodination of salt is the most widespread and cost-effective method of prevention. Administration of iodized oil has been used only in severely endemic areas and in regions where reliable provision of iodinized salt is prevented by geographical barriers or political factors. However, iodized oil has been helpful in the start-up phase of prevention programs using iodized salt, either as an emergency measure or as a mean of convincing officials of the efficacy of iodine prophylaxis.

Adult↗

PubMed1998

Thyroid and fertility.

The aim of this work is to specify the relationship between the thyroid function and the hypothalamo-hypophyso-gonadal axis. Qualitative and quantitative repercussions of a thyroid pathology on human or animal fertility, male or female are very variable. A review of mechanisms of action is presented, illustrating: the complexity of the phenomena in cause; the necessity not to dissociate thyroid and reproductive function either clinically or biologically; the serious consequences of either undetected or untreated neo-natal thyroid pathology.

Animals↗