Field Evaluation of Calypte’s AWARE™ Blood Serum Plasma (BSP) and Oral Mucosal Transudate (OMT) Rapid Tests for Detecting Antibodies to HIV-1 and 2 in Plasma and Oral Fluid

As programs to prevent and care for HIV-infected persons are scaled-up in Africa, there is the need for continuous evaluation of the performance of test kits that could best support these programs. The present study evaluated the sensitivity, specificity, ease of use, and cost of AWARE ™ Blood Serum Plasma (BSP) and Oral Mucosal Transudate (OMT) Rapid HIV-1/2 test kits using real-time and archived samples of HIV-infected persons from Cameroon. Matched whole blood and OMT specimens were collected prospectively from HIV-positive and HIV-negative persons from different regions of Cameroon and tested using the AWARE ™ BSP and OMT test kits, respectively. These results were compared to the gold standard that included a combination of Determine HIV-1/2 and Enzygnost HIV-1/2. The BSP Rapid test kit was further evaluated using well characterized panels of HIV-2 and HIV-1 group O samples. Cost and end-user analysis of the OMT test kit was done by comparing its actual cost, consumables, safety, bench time and manipulation with other test kits. Of the 732 matched samples, 412 (56.3%) and 320 (43.7%) were from females and males, respectively. Of these samples, 23 (3.1%) gave discordant results between Determine HIV-1/2 and Enzygnost HIV1/2 and were excluded from the analysis. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the AWARE™ BSP were 100%. The AWARE™ OMT had 98.8% sensitivity, 98.9% specificity, 98.0% PPV and 99.4% NPV. The results of a well-characterized archived panel of HIV-2 (n=7) and HIV-1 group O (n=3) samples using the AWARE™ BSP Rapid test kit gave 100% concordance. Total per patient cost of the AWARE OMT rapid test kit was US$4.72 compared to a mean cost of US$7.33 ± 0.11 for the other test kits. Both the AWARE™ BSP and OMT Rapid test kits demonstrated high sensitivities and specificities on all samples tested and were well adapted for use in resource-constrained settings with high HIV heterogeneity such as Cameroon. The AWARE ™ HIV-1/2 OMT Rapid test kit appears to be the cheapest, safest and easiest to use compared with other available test kits

Anticonvulsant activity of extracts from six Cameroonian plants traditionally used to treat epilepsy

Epilepsy remains one of the leading public health problems that affects about 50 million people worldwide, thus stressing the need for new anticonvulsant drug. This study was designed to evaluate the anticonvulsant activity against Penty lenetetrazole induced–convulsion in mice. Plants were extracted by maceration with water or organic solvents. The extracts were tested against PTZ-induced convulsion by measuring onset seizure, clonic seizure onset, convulsion duration, death time and percentage of protection. A. cordifolia leaf extract protected all animals from death at 1000 mg/kg. A. muricata stem extract delayed seizures at 200 and 400 mg/kg, while the onset of tonicoclonic (TC) seizures was significantly delayed at the highest doses tested for the seed extract (800 mg/kg). Stem and leaf extracts of A. senegalensis significantly delayed seizure onset at all doses. D. adescendes extract significantly protected mice from death. F. thonningii leaf extract at the smallest dose tested (200 mg/kg), significantly delayed the seizure onset and the occurrence of TC convulsions. Bark extract of V. doniana significantly delayed the seizure onset at all doses tested. The results obtained corroborate with the traditional claims that these plants can be a valuable source of new anticonvulsant compounds.Keywords: Plant extracts, PTZ-induced seizures, anticonvulsant effect, mice

Population genetics of Trypanosoma brucei circulating in Glossina palpalis palpalis and domestic animals of the Fontem sleeping sickness focus of Cameroon

Background: Human African Trypanosomiasis is still a public health threat in Cameroon. To assess Trypanosoma brucei strains circulating in the Fontem sleeping sickness focus, we conducted a genetic structure study using microsatellites to assess genotypes circulating in both tsetse flies and domestic animals. Method: For this study, pyramidal traps were set up and 2695 tsetse flies were collected and 1535 (57%) living flies were dissected and their mid- guts collected. Furthermore, blood samples were collected from 397 domestic animals (pigs, goats, sheep and dogs). DNA was extracted from midguts and blood samples, and specific primers were used to identify trypanosomes of the subgenus Trypanozoon. All positive samples were genetically characterized with seven microsatellite markers. Results: Seventy five (4.7%) midguts of tsetse flies and 140 (35.2%) domestic animals were found infected by trypanosomes of the subgenus Trypanozoon. The genetic characterization of 215 Trypanozoon positive samples (75 from tsetse and 140 from animals) revealed a genetic diversity between Trypanosoma brucei circulating in tsetse and domestic animals. Of these positive samples, 87 (40.5%) single infections were used here to investigate the population genetics of Trypanosoma brucei circulating in tsetse and domestic animals. The dendrogram illustrating the genetic similarities between Trypanosoma brucei genotypes was subdivided into four clusters. The samples from tsetse belonged to the same cluster whereas the samples from domestic animals and espcially pigs were distributed in the four clusters. Conclusion: Pigs appeared as the animal species harboring the highest number of different Trypanosoma brucei strains. They may play an important role in the propagation of different genotypes. The FST values revealed a sub structuration of Trypanosoma brucei according to hosts and sometimes villages. The data obtained from this study may have considerable importance for the understanding of the transmission and the spread of specific genotypes of Trypanosoma brucei

Identification of different trypanosome species in the mid-guts of tsetse flies of the Malanga (Kimpese) sleeping sickness focus of the Democratic Republic of Congo

<p>Abstract</p> <p>Background</p> <p>The Malanga sleeping sickness focus of the Democratic Republic of Congo has shown an epidemic evolution of disease during the last century. However, following case detection and treatment, the prevalence of the disease decreased considerably. No active survey has been undertaken in this focus for a couple of years. To understand the current epidemiological status of sleeping sickness as well as the animal African trypanosomiasis in the Malanga focus, we undertook the identification of tsetse blood meals as well as different trypanosome species in flies trapped in this focus.</p> <p>Methods</p> <p>Pyramidal traps were use to trap tsetse flies. All flies caught were identified and live flies were dissected and their mid-guts collected. Fly mid-gut was used for the molecular identification of the blood meal source, as well as for the presence of different trypanosome species.</p> <p>Results</p> <p>About 949 <it>Glossina palpalis palpalis</it> were trapped; 296 (31.2%) of which were dissected, 60 (20.3%) blood meals collected and 57 (19.3%) trypanosome infections identified. The infection rates were 13.4%, 5.1%, 3.5% and 0.4% for <it>Trypanosoma congolense</it> savannah type, <it>Trypanosoma brucei</it> s.l., <it>Trypanosoma congolense</it> forest type and <it>Trypanosoma vivax</it>, respectively. Three mixed infections including <it>Trypanosoma brucei</it> s.l. and <it>Trypanosoma congolense</it> savannah type, and one mixed infection of <it>Trypanosoma vivax</it> and <it>Trypanosoma congolense</it> savannah type were identified<it>.</it> Eleven <it>Trypanosoma brucei gambiense</it> infections were identified; indicating an active circulation of this trypanosome subspecies. Of all the identified blood meals, about 58.3% were identified as being taken on pigs, while 33.3% and 8.3% were from man and other mammals, respectively.</p> <p>Conclusion</p> <p>The presence of <it>Trypanosoma brucei</it> in tsetse mid-guts associated with human blood meals is indicative of an active transmission of this parasite between tsetse and man. The considerable number of pig blood meals combined with the circulation of <it>Trypanosoma brucei gambiense</it> in this focus suggests a transmission cycle involving humans and domestic animals and could hamper eradication strategies. The various species of trypanosomes identified in the Malanga sleeping sickness focus indicates the coexistence of animal and human African Trypanosomiasis. The development of new strategies integrating control measures for human and animal trypanosomiasis may enable the reduction of the control costs in this locality.</p