Biomedical subjects

S Geerts

Publications and source records attributed to S Geerts.

At least 37 records · Page 2Linked to original sources

PubMed2004

Trypanosoma vivax: a simplified protocol for in vivo growth, isolation and cryopreservation.

A rodent adapted clone of Trypanosoma vivax was used to infect cyclophosphamide treated mice and rats. Fresh blood containing trypanosomes, was centrifuged in a density gradient of three Percoll solutions, 1.07, 1.06, 1.05 g/ml, respectively, carefully layered on top of each other. The yields of this simple procedure for trypanosome purification were about six times higher than those obtained with the conventional anion-exchange columns. Cryopreservation of trypanosomes using glycerol yielded 90% viable parasites, whereas using dimethylsulfoxide, a more commonly used cryoprotectant, the viability was only 35%.

Animals↗

PubMed2004

The adjustment of curricula in veterinary faculties in sub-Saharan Africa.

A survey was conducted by questionnaire to assess the current undergraduate curricula in the veterinary faculties of sub-Saharan Africa. The survey also examined how such curricula are adjusted for crucial developments in the veterinary field, such as privatisation, decentralisation and globalisation, with the increasing risk of transboundary diseases. The results demonstrate that most of these faculties face serious shortages, both in their budgets and of qualified personnel. Most faculties do not have formal feedback systems to allow former graduates to contribute to periodic reviews of the curricula. Although some north-south and south-south collaboration exists among African veterinary faculties, more intensive regional collaboration at both undergraduate and postgraduate level would allow optimal use of the available funds and human resources. The creation of a regional veterinary council and a committee of deans would be an excellent step forward in ensuring internationalisation and harmonisation of veterinary education and establishing a regional accreditation system.

Accreditation↗

PubMed2004

The provision of animal health care to smallholders in Africa: an analytical approach.

Many of the problems associated with the delivery of quality veterinary services to smallholders in Africa are attributed to the complexity of the provision of animal health care (AHC) in sub-Saharan Africa. In this region, a holistic and analytical approach is needed to determine area-specific requirements for sustainable, and thus quality, AHC. This study examines three components of the animal health care system in sub-Saharan Africa, namely, the structure, the process and the outcomes. It focuses particularly on the factors that contribute to the quality of the structure and the process. For this purpose, two measures of quality are used, i.e. availability (in relation to the structure) and acceptability (in relation to the process). The authors identify factors that affect the availability and acceptability of AHC and suggest ways in which they, and hence the quality of AHC provided to smallholders in Africa, can be improved.

Africa South of the Sahara↗

PubMed2003

Taeniosis-cysticercosis in man and animals in the Sierra of Northern Ecuador.

Taenia solium is endemic in the Andean region of Ecuador. The recent rediscovery of Taenia saginata in humans urges to reconsider some assumptions in relation to the epidemiology of the taeniosis/cysticercosis complex in this country.Therefore, data were compiled on the infection of both tapeworms in man and animals in Pichincha and Imbabura provinces in the Andean region, north of Quito. On post mortem inspection 3 out of 806 (0.37%) carcasses had T. saginata metacestodes, however, 35 sera out of 869 (4.03%) showed circulating antigen in a monoclonal antibody-based sandwich ELISA (Ag-ELISA). Porcine cysticercosis was detected in 15 out of 2896 (0.52%) carcasses and 93 out of 1032 serum samples (9.01%) were positive in Ag-ELISA. In humans, 4.99% (215 out of 4306) cases of antigen positives were found, whereas coprological examination of 1935 stools resulted in 30 positive cases (1.55%). The limited number of adult tapeworms (29) that were collected does not allow firm conclusions on the proportion of each species, but in total 21 specimen were identified as T. saginata and 8 as T. solium. These data have been discussed in view of the epidemiology of human cysticercosis.

Animals↗

PubMed2003

PCR-RFLP using Ssu-rDNA amplification: applicability for the diagnosis of mixed infections with different trypanosome species in cattle.

The use of a single restriction fragment length polymorphism (RFLP)-PCR assay which is able to characterise all important bovine trypanosome species was evaluated for the detection of mixed infections with Trypanosoma brucei brucei, Trypanosoma theileri, Trypanosoma congolense and Trypanosoma vivax. Results showed that mixed infections are detectable at a minimum ratio of 2%/98% of standardised DNA solutions with a concentration of 10 ng ml(-1). All mixed infections gave clear profiles that could be easily differentiated except with T. theileri and T. congolense where the T. theileri band was concealed by the T. congolense profile.

Animals↗

PubMed2003

Echinococcus multilocularis (Cestoda, Taeniidae) in Red foxes (Vulpes vulpes) in northern Belgium.

The first record of the tapeworm Echinococcus multilocularis (Cestoda, Taeniidae) in Red foxes (Vulpes vulpes) in northern Belgium is described. Between 1996 and 1999, 237 dead foxes were examined for the presence of this tapeworm using the intestinal scraping technique. Four foxes (1.7%) were found to be infected with E. multilocularis and showed medium to very high parasitic burdens. Three infected foxes originated from the south of the study area and the fourth animal came from the north of the study area near the border with The Netherlands. These findings are discussed in relation to the high endemicity of E. multilocularis in southern Belgium and to the increased distribution of the Red fox (V. vulpes) in northern Belgium during the last two decades.

Animals↗

PubMed2003

Evaluation of tongue inspection and serology for diagnosis of Taenia solium cysticercosis in swine: usefulness of ELISA using purified glycoproteins and recombinant antigen.

Evaluation of serology using glycoproteins (GPs) purified by preparative isoelectric focusing (pH 8.8) and recombinant chimeric antigen (RecTs) of Taenia solium was carried out using (1) blood samples on filter papers from pigs infected with different doses of eggs of T. solium in Mexico, (2) serum samples from pigs found infected naturally in Vietnam and Ecuador and (3) serum samples from pigs suspected to be infected with T. solium by tongue inspection in Tanzania. Antibody responses (IgG) were detectable in experimentally infected pigs confirmed harbouring 16 or more cysts at necropsy from 30 days after egg inoculation. One of three pigs naturally infected and harbouring 2.5 cysts/kg muscle and most of pigs harbouring=5.0 cysts/kg were also seropositive by ELISA. Although pigs may be infected with other taeniid species such as Taenia hydatigena, pigs harbouring this parasite were negative in ELISA. Approximately, 76 and 78% of sera from pigs having nodule(s) in the tongue (positive tongue inspection) were serologically positive by both ELISA and immunoblot, respectively. Furthermore, approximately 34 and 18% of sera from pigs having no nodules in the tongue (negative tongue inspection) were also seropositive by ELISA and immunoblot, respectively. ELISA using the two antigens was more sensitive than immunoblot and reliable for differentiation of pigs infected with cysticerci of T. solium from those either uninfected or infected with other taeniid species. Pigs without nodule by tongue inspection should be checked serologically in endemic areas.

Animals↗

PubMed2003

Kinetics of circulating antigens in pigs experimentally infected with Taenia solium eggs.

Three groups of four piglets were experimentally infected with different doses (10(3), 10(4) and 10(5)) of Taenia solium eggs whereas a fourth group of two pigs received gravid proglottids. At autopsy 6 months post infection, the two latter pigs were heavily infected with more than 3000 living cysts per kg of muscle. Ten of the 12 other pigs harboured light infections, i.e. between 2 and 107 cysticerci, 42.4% of which were degenerated. The two remaining pigs had no detectable cysts at post mortem examination. Circulating antigens (CA) were detected in the sera of all pigs harbouring living cysticerci using a monoclonal antibody based ELISA. CA were first detected between 2 and 6 weeks post infection and remained present generally throughout the entire observation period even in pigs carrying only five to eight living cysts, although strong fluctuations of the level of CA were observed in some pigs. In animals without living cysts at post mortem CA were only detected for a short period and disappeared presumably when the cysticerci became degenerated. The minimum number of living cysts, which could be detected using this ELISA, was 1.

Animals↗

PubMed2003

PCR-RFLP using Ssu-rDNA amplification as an easy method for species-specific diagnosis of Trypanosoma species in cattle.

A single polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) assay was used to characterise all important bovine trypanosome species. This is the first report of a sensitive pan-trypanosome PCR assay amplifying all species including T. vivax to a comparable extent using a single primer pair. A semi-nested PCR approach resulted in the detection of one T. congolense trypanosome genome/40 microl of blood, applied as buffy coat on filter paper. Restriction enzyme analysis using Msp1 and Eco571 gave a clear distinction between T. congolense, T. brucei, T. vivax and T. theileri. Several subgroups within the T. congolense group could be distinguished but no differences between the species belonging to the subgenus Trypanozoon or between T. simiae and T. theileri could be found. The use of MboII restriction enzyme allowed differentiation between T. simiae and T. theileri. The potential of the essay to be used as a suitable diagnostic tool is discussed.

Animals↗

PubMed2003

A seroepidemiological study of human cysticercosis in West Cameroon.

We studied the occurrence of human cysticercosis in 4993 individuals from three rural communities of Menoua Division, West Province of Cameroon. Circulating antigens of Taenia solium metacestodes were detected in 0.4%, 1.0% and 3.0% of the serum samples taken in Bafou, Bamendou and Fonakekeu, respectively, and examined using a monoclonal antibody-based enzyme-linked immunosorbent assay. This test detects only carriers of living cysticerci and gives thus a good idea of the presence of active cysticercosis. The percentage of persons infected with cysticercosis increased with age. Twenty-two of the 34 seropositives underwent computed tomography (CT) of the brain. Thirteen of them were CT-scan positive, which shows that neurocysticercosis was present in 59.1% of the tested seropositive persons. No living cysticerci were detected among 20 seronegative people. About 20.6% of the seropositives had a history of or current taeniasis against only 1.9% of the seronegatives. Based on these figures and on the data on porcine cysticercosis (prevalence: 11%) and human taeniasis (prevalence: 0.13%) collected in the same region, we conclude that T. solium cysticercosis is an endemic, but overlooked public health problem in West Cameroon.

Adolescent↗

PubMed2003

Follow-up of neurocysticercosis patients after treatment using an antigen detection ELISA.

Seven patients with active neurocysticercosis (NCC) received an eight days treatment with albendazole and were followed up using computed tomography (CT-scan) and a monoclonal antibody based ELISA for the detection of circulating antigen (Ag-ELISA). Only three patients were cured as was shown by CT-scan and by the disappearance of circulating antigens one month after treatment. After a second course of albendazole therapy, two other patients became seronegative. CT-scan showed the disappearance of viable cysts in all persons who became seronegative whereas patients who were not cured remained seropositive. These preliminary results show that this Ag-ELISA is a promising technique for monitoring the success of treatment of NCC patients because of the excellent correlation between the presence of circulating antigens and of viable brain cysts.

Adolescent↗

PubMed2003

Porcine cysticercosis in village pigs of North-West Cameroon.

A study was carried out in two villages and one marketplace of the Batibo sub-division in North-West Cameroon to determine the prevalence of porcine cysticercosis. The results showed that 4.44% of 383 pigs were positive at tongue examination whereas ELISA detected circulating antigens in 27.7% of 271 pig sera. A questionnaire survey in 140 pig-raising households indicated that 59.3% of them lacked latrines while in 75.7% of the households members defecated directly into pigpens. The seroprevalence of porcine cysticercosis was significantly higher in households without latrines than in those with latrines. Similarly, significantly more seropositive pigs were present in households that defecated in the pig pens (35.5%) than in those that did not (14.4%). Although 91.4% of pig raising households did know of pig cysticercosis, only 28.6% were aware of the link with human taeniasis and only 10.7% were aware of human cysticercosis.

Animal Husbandry↗

PubMed2002

Monitoring the correct use of isometamidium by farmers and veterinary assistants in Eastern Province of Zambia using the isometamidium-ELISA.

A survey to monitor the use of trypanocidal drugs by cattle breeders was conducted in Zambia. Use was made of a questionnaire and of the isometamidium-ELISA technique. One hundred and twenty-two farmers and 50 veterinary assistants were interviewed. The isometamidium-ELISA was used to monitor the isometamidium serum concentration in 72 cattle, 1 week after unsupervised treatment by 56 farmers and 16 veterinary assistants. Although there was no clear indication of underestimation of the weight of the animals and although farmers had adequate knowledge of the correct usage of isometamidium, the results suggest frequent underdosing when considering isometamidium serum concentrations 1 week after treatment. In 76% of the cases, the expected protection period was equal or shorter than 28 days and equal or shorter than 33 days in 90% of the treated cattle.

Animals↗

PubMed2002

Susceptibility of trypanotolerant West African Dwarf goats and F1 crosses with the susceptible Sahelian breed to experimental Trypanosoma congolense infection and interactions with helminth infections and different levels of diet.

Forty pure West African Dwarf (WAD) goats and 35 of its F1 crosses with the Sahelian breed were used in a multifactorial experimental design to evaluate the effects of an experimental Trypanosoma congolense infection and interactions with natural helminth infections and different levels of diet on health and productivity of these two breeds. Trypanosome infection caused a severe drop in packed cell volume (PCV), but this was not significantly affected by breed. Neither deworming nor diet had any effect on the course of anaemia after trypanosome infection. The mean score of parasitaemia tended to be higher in crossbreeds than in WAD goats although this was not significant (P>0.05). Similarly, the antibody response to trypanosome infection was not significantly different between breeds. Parasitaemia level was significantly influenced by the level of diet with the group under high supplementation having a higher mean parasitaemia score than the group under low supplementation. Weight loss due to trypanosome infection tended to be greater in crossbreeds than in WAD goats (P>0.05). During this study, there was no difference in mean helminth egg output between crossbred and WAD goats. However, between weeks 4 and 10 after trypanosome infection (corresponding to a period of heavy rainfall and highly infective pastures), the mean egg output was higher in the crossbreeds. The immunosuppressive effect of trypanosome infections was revealed by a lower antibody response to Haemonchus contortus in infected animals compared to the uninfected controls. Trypanosome infection tended to increase strongyle egg output. This study did no reveal any superior trypanotolerance of WAD goats compared to crossbreeds.

Animal Feed↗

PubMed2002

Epidemiological survey of swine cysticercosis in two rural communities of West-Cameroon.

To determine the prevalence of porcine cysticercosis, a survey was carried out in 27 villages belonging to two rural communities of West-Cameroon (Bafou and Bamendou). Between January and August, 2000, a total of 707 pigs were examined serologically and by tongue inspection. Serum samples were examined for circulating parasite antigen using a monoclonal antibody-based sandwich enzyme-linked-immunosorbent assay (Ag-ELISA) and for antibodies against cysticerci (Ab-ELISA). Seventy eight samples (11.0%) were found positive in the Ag-ELISA and 154 (21.8%) in the Ab-ELISA, while by tongue inspection on the same animals cysticerci were detected in 43 pigs (6.1%). Gibbs sampling using results of these three tests indicated that the estimated prevalence of porcine cysticercosis was 10.9%. Analysis of the Ag-ELISA results demonstrated that adult pigs showed a significantly higher seroprevalence (15%) than young ones (8.4%). There was no statistical difference in cysticercosis prevalence in pigs raised in households with or without a latrine. Animals that were reported to be usually confined were significantly less infected (9.9%) than free-roaming pigs (16.2%). Infection rates were significantly higher in pigs that had access to human faeces (13.8%) than those which did not have access (9.1%). This study has identified some community behavioural and environmental practices that should be modified to prevent continuous transmission of porcine cysticercosis.

Animal Husbandry↗

PubMed2002

Survey for Trichinella spp. in red foxes (Vulpes vulpes) in Belgium.

Concurrently with a survey for Echinococcus multilocularis in the red fox (Vulpes vulpes) in Flanders, northern Belgium, serological and parasitological analyses for Trichinella spp. were carried out from 1996 to 1999. Muscle samples from foxes in Wallonia, southern Belgium, were obtained during a survey for rabies and alveolar echinococcosis from 1998 to 2000. In muscle samples from tongue, diaphragm, hindlegs and tail of 179 Flemish foxes no larvae were found by trichinoscopy. Serum and muscle juice of, respectively 176 and 26 animals were examined using an ELISA for the detection of antibodies against excretory-secretory (ES) antigen. There were eight (4.5%) positive sera, but no positive muscle juice samples. All muscle samples from 639 foxes in Wallonia proved to be negative for larvae in artificial digestion. Serum and muscle juice of 130 and 478 foxes, respectively were examined in ES-ELISA. There were 61 (46.9%) positive sera and 90 (18.8%) positive muscle juice samples. A comparison between 88 serum and muscle juice samples of the same foxes showed that only half of the serum-positive animals were detected using muscle juice. However, for establishing the true meaning of these results, a more profound epidemiological study on the vulpine population in Belgium is necessary.

Animals↗

PubMed2002

[Taenia solium taeniasis/cysticercosis in the Menoua division (West Cameroon)].

The present study was carried out between August 1999 and April 2000 with the objective of determining the prevalence of Taenia solium taeniasis in two village communities of Bafou and Bamendou in the Menoua division (West Cameroon). Four (0.13%) out of 3,109 faecal samples were positive for Taenia spp. eggs using the flotation technique. Three of the four worms expelled were T. solium whereas the other one was T. saginata. Two cases of cysticercosis were diagnosed in one of the families with a T. solium carrier. Furthermore, coprological and serological investigations for T. solium taeniasis and cysticercosis were carried out among butchers and/or tongue inspectors (n = 137) of the city of Dschang. The results were compared with those of a control group (n = 198). Taenia spp. eggs were not detected by microscopic examination. The prevalence of cysticercosis in the two groups was relatively similar (3.6 and 4.5% respectively).

Animals↗

PubMed2002

Comparison of conventional techniques to differentiate between Taenia solium and Taenia saginata and an improved polymerase chain reaction-restriction fragment length polymorphism assay using a mitochondrial 12S rDNA fragment.

Given the constraints of classical diagnostic methods, i.e., morphological and isoenzymatic studies of proglottids, a polymerase chain reaction test complemented with restriction enzyme analysis has been modified by redesigning one of the primers to reduce nonspecific amplifications experienced when using field samples. The use of these new, highly cestode-specific primers and the restriction enzyme Ddel led to the development of a diagnostic assay that clearly distinguishes between Taenia saginata and T. solium proglottids in field samples. This assay confirms the presence of T. saginata in Ecuador. DNA amplification of some of these taeniids showed different patterns, suggesting the possibility that strain differences exist. These results demonstrate the need for development of useful molecular assays as reliable tools for epidemiological studies on cestodes.

Animals↗