Search tips
Search criteria

Results 1-7 (7)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  Exploring Risk Behaviors and Vulnerability for HIV among Men Who Have Sex with Men in Abidjan, Cote d′Ivoire: Poor Knowledge, Homophobia and Sexual Violence 
PLoS ONE  2014;9(6):e99591.
Men who have sex with men (MSM) are at high risk of HIV. Few data are available on MSM and HIV-related risk behaviors in West Africa. We aimed to describe risk behaviors and vulnerability among MSM in Abidjan, Cote d′Ivoire. We conducted a cross-sectional respondent-driven sampling survey with 601 MSM in 2011–2012. Sociodemographic and behavioural data as well as data related to emotional state and stigma were collected. Population estimates with 95% confidence intervals were produced. Survey weighted logistic regression was used to assess factors associated with inconsistent condom use in the prior 12 months. Most MSM were 24 years of age or younger (63.9%) and had attained at least primary education (84.4%). HIV risk behaviors such as low condom and water-based lubricant use, high numbers of male and female sex partners, and sex work were frequently reported as well as verbal, physical and sexual abuse. Inconsistent condom use during anal sex with a male partner in the prior 12 months was reported by 66.0% of the MSM and was positively associated with history of forced sex, alcohol consumption, having a regular partner and a casual partner, having bought sex, and self-perception of low HIV risk. MSM in Abidjan exhibit multiple and frequent HIV-related risk behaviors. To address those behaviours, a combination of individual but also structural interventions will be needed given the context of stigma, homophobia and violence.
PMCID: PMC4069062  PMID: 24959923
2.  Long-term research sites as refugia for threatened and over-harvested species 
Biology Letters  2011;7(5):723-726.
The presence of researchers, ecotourists or rangers inside protected areas is generally assumed to provide a protective effect for wildlife populations, mainly by reducing poaching pressure. However, this assumption has rarely been empirically tested. Here, we evaluate and quantify the conservation benefits of the presence of a long-term research area in Taï National Park, Côte d'Ivoire. A wildlife survey following 225 km of line transects revealed considerably higher primate and duiker encounter rates within the research area when compared with adjacent areas. This positive effect was particularly pronounced for threatened and over-harvested species, such as the endangered red colobus monkey (Procolobus badius). This pattern was clearly mirrored by a reversed gradient in signs of poaching, which decreased towards and inside the research area, a trend that was also supported with park-wide data. This study demonstrates that even relatively simple evidence-based analytical approaches can bridge the gap between conservation theory and practice. In addition, it emphasizes the value of establishing long-term research sites as an integral part of protected area management.
PMCID: PMC3169048  PMID: 21450724
conservation; research; line transect; threatened species; protected area
3.  Towards an Optimal Design of Target for Tsetse Control: Comparisons of Novel Targets for the Control of Palpalis Group Tsetse in West Africa 
Tsetse flies of the Palpalis group are the main vectors of sleeping sickness in Africa. Insecticide impregnated targets are one of the most effective tools for control. However, the cost of these devices still represents a constraint to their wider use. The objective was therefore to improve the cost effectiveness of currently used devices.
Methodology/Principal Findings
Experiments were performed on three tsetse species, namely Glossina palpalis gambiensis and G. tachinoides in Burkina Faso and G. p. palpalis in Côte d'Ivoire. The 1×1 m2 black blue black target commonly used in W. Africa was used as the standard, and effects of changes in target size, shape, and the use of netting instead of black cloth were measured. Regarding overall target shape, we observed that horizontal targets (i.e. wider than they were high) killed 1.6-5x more G. p. gambiensis and G. tachinoides than vertical ones (i.e. higher than they were wide) (P<0.001). For the three tsetse species including G. p. palpalis, catches were highly correlated with the size of the target. However, beyond the size of 0.75 m, there was no increase in catches. Replacing the black cloth of the target by netting was the most cost efficient for all three species.
Reducing the size of the current 1*1 m black-blue-black target to horizontal designs of around 50 cm and replacing black cloth by netting will improve cost effectiveness six-fold for both G. p. gambiensis and G. tachinoides. Studying the visual responses of tsetse to different designs of target has allowed us to design more cost-effective devices for the effective control of sleeping sickness and animal trypanosomiasis in Africa.
Author Summary
Tsetse flies transmit trypanosomes causing sleeping sickness and nagana. Controlling tsetse prevents transmission of these diseases. Insecticide impregnated targets are highly effective but are too costly. This study aims to improve the cost effectiveness of targets. Experiments were performed on three tsetse species in Burkina Faso or Côte d'Ivoire. Effects of target size, shape, and the use of netting instead of black cloth were measured. We observed that targets wider than they are high (horizontal target) killed 1.6-5x more G. p. gambiensis and G. tachinoides than vertical ones. Catches were highly correlated with the size of the target up to a target size of 0.75 m, beyond which there was no further increase in catches. Replacing the black cloth of the target by netting did not change catches, but was far cheaper. Hence reducing the size of the current 1 m×1 m black-blue-black target to an horizontal 0.75×0.5 m net blue net target will improve cost effectiveness six-fold for both G. p. gambiensis and G. tachinoides. Studying the visual responses of tsetse to different designs of target has allowed us to design more cost-effective devices for the effective control of sleeping sickness and animal trypanosomiasis in Africa.
PMCID: PMC3176748  PMID: 21949896
4.  How Do Tsetse Recognise Their Hosts? The Role of Shape in the Responses of Tsetse (Glossina fuscipes and G. palpalis) to Artificial Hosts 
Palpalis-group tsetse, particularly the subspecies of Glossina palpalis and G. fuscipes, are the most important transmitters of human African trypanomiasis (HAT), transmitting >95% of cases. Traps and insecticide-treated targets are used to control tsetse but more cost-effective baits might be developed through a better understanding of the fly's host-seeking behaviour. Electrocuting grids were used to assess the numbers of G. palpalis palpalis and G. fuscipes quanzensis attracted to and landing on square or oblong targets of black cloth varying in size from 0.01 m2 to 1.0 m2. For both species, increasing the size of a square target from 0.01 m2 (dimensions = 0.1×0.1 m) to 1.0 m2 (1.0×1.0 m) increased the catch ∼4x however the numbers of tsetse killed per unit area of target declined with target size suggesting that the most cost efficient targets are not the largest. For G. f. quanzensis, horizontal oblongs, (1 m wide×0.5 m high) caught ∼1.8x more tsetse than vertical ones (0.5 m wide×1.0 m high) but the opposite applied for G. p. palpalis. Shape preference was consistent over the range of target sizes. For G. p. palpalis square targets caught as many tsetse as the oblong; while the evidence is less strong the same appears to apply to G. f. quanzensis. The results suggest that targets used to control G. p. palpalis and G. f. quanzensis should be square, and that the most cost-effective designs, as judged by the numbers of tsetse caught per area of target, are likely to be in the region of 0.25×0.25 m2. The preference of G. p. palpalis for vertical oblongs is unique amongst tsetse species, and it is suggested that this response might be related to its anthropophagic behaviour and hence importance as a vector of HAT.
Author Summary
While the numbers of cases of human African trypanosomiasis (HAT) is now less than 10,000 reported cases per year, progress against the tsetse species that spread the disease is poor, with ∼10 million square kilometres of sub-Saharan Africa still being infested. This widespread persistence of vectors and reservoir hosts threatens the long-term sustainability of recent gains against HAT. Better progress against the vector would be achieved by developing cheap, effective and practical methods of tsetse control. Toward this end, we are improving the design of insecticide-treated targets to attract and kill tsetse. Here we show that for two important vectors of HAT, Glossina palpalis palpalis in Côte d'Ivoire and Glossina fuscipes quanzensis in the Democratic Republic of Congo, small (between 0.25 m and 0.5 m square) targets of black cloth with equally sized panel of fine black netting are ∼10x more cost-effective than the larger (∼1 m square) targets or traps commonly in use.
PMCID: PMC3149008  PMID: 21829734
5.  Pathotype and Antibiotic Resistance Gene Distributions of Escherichia coli Isolates from Broiler Chickens Raised on Antimicrobial-Supplemented Diets▿†  
Applied and Environmental Microbiology  2009;75(22):6955-6962.
The impact of feed supplementation with bambermycin, monensin, narasin, virginiamycin, chlortetracycline, penicillin, salinomycin, and bacitracin on the distribution of Escherichia coli pathotypes in broiler chickens was investigated using an E. coli virulence DNA microarray. Among 256 E. coli isolates examined, 59 (23%) were classified as potentially extraintestinal pathogenic E. coli (ExPEC), while 197 (77%) were considered commensal. Except for chlortetracycline treatment, the pathotype distribution was not significantly different among treatments (P > 0.05). Within the 59 ExPEC isolates, 44 (75%) were determined to be potentially avian pathogenic E. coli (APEC), with the remaining 15 (25%) considered potentially “other” ExPEC isolates. The distribution within phylogenetic groups showed that 52 (88%) of the ExPEC isolates belonged to groups B2 and D, with the majority of APEC isolates classified as group D and most commensal isolates (170, 86%) as group A or B1. Indirect assessment of the presence of the virulence plasmid pAPEC-O2-ColV showed a strong association of the plasmid with APEC isolates. Among the 256 isolates, 224 (88%) possessed at least one antimicrobial resistance gene, with nearly half (107, 42%) showing multiple resistance genes. The majority of resistance genes were distributed among commensal isolates. Considering that the simultaneous detection of antimicrobial resistance tet(A), sulI, and blaTEM genes and the integron class I indicated a potential presence of the resistance pAPEC-O2-R plasmid, the results revealed that 35 (14%) of the isolates, all commensals, possessed this multigene resistance plasmid. The virulence plasmid was never found in combination with the antimicrobial resistance plasmid. The presence of the ColV plasmid or the combination of iss and tsh genes in the majority of APEC isolates supports the notion that when found together, the plasmid, iss, and tsh serve as good markers for APEC. These data indicate that different resistant E. coli pathotypes can be found in broiler chickens and that the distribution of such pathotypes and certain virulence determinants could be modulated by antimicrobial agent feed supplementation.
PMCID: PMC2786528  PMID: 19749070
6.  Prospects for the Development of Odour Baits to Control the Tsetse Flies Glossina tachinoides and G. palpalis s.l. 
Field studies were done of the responses of Glossina palpalis palpalis in Côte d'Ivoire, and G. p. gambiensis and G. tachinoides in Burkina Faso, to odours from humans, cattle and pigs. Responses were measured either by baiting (1.) biconical traps or (2.) electrocuting black targets with natural host odours. The catch of G. tachinoides from traps was significantly enhanced (∼5×) by odour from cattle but not humans. In contrast, catches from electric targets showed inconsistent results. For G. p. gambiensis both human and cattle odour increased (>2×) the trap catch significantly but not the catch from electric targets. For G. p. palpalis, odours from pigs and humans increased (∼5×) the numbers of tsetse attracted to the vicinity of the odour source but had little effect on landing or trap-entry. For G. tachinoides a blend of POCA (P = 3-n-propylphenol; O = 1-octen-3-ol; C = 4-methylphenol; A = acetone) alone or synthetic cattle odour (acetone, 1-octen-3-ol, 4-methylphenol and 3-n-propylphenol with carbon dioxide) consistently caught more tsetse than natural cattle odour. For G. p. gambiensis, POCA consistently increased catches from both traps and targets. For G. p. palpalis, doses of carbon dioxide similar to those produced by a host resulted in similar increases in attraction. Baiting traps with super-normal (∼500 mg/h) doses of acetone also consistently produced significant but slight (∼1.6×) increases in catches of male flies. The results suggest that odour-baited traps and insecticide-treated targets could assist the AU-Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC) in its current efforts to monitor and control Palpalis group tsetse in West Africa. For all three species, only ∼50% of the flies attracted to the vicinity of the trap were actually caught by it, suggesting that better traps might be developed by an analysis of the visual responses and identification of any semiochemicals involved in short-range interaction.
Author Summary
Sleeping sickness, otherwise known as Human African Trypanosomiasis, continues to be a serious threat to human health. This disease, which is transmitted by tsetse flies, normally afflicts poor and isolated communities. No vaccines or prophylactic drugs are available to prevent the disease, which, once it has been contracted, is treated with curative drugs that often prove ineffective because of emerging disease resistance in the trypanosomes. These drugs can often have unpleasant and sometimes fatal side effects. Prospects for development of effective vaccines or prophylactic drugs are poor. Killing the tsetse fly vector remains the only method of preventing disease transmission. This can be done at either a local level or regionally. However, a major problem is the cost and logistical difficulty of implementing fly control programmes. To overcome this, we are trying to develop cost-effective insecticide-treated targets by identifying chemicals that will increase the numbers of tsetse that will be lured to a target and killed. Here we show that G. tachinoides is significantly attracted to cow odour, G. p. gambiensis to both cow and human odour, and G. p. palpalis to odours from pigs and humans. This opens the way for further work to identify the attractants present in these natural odours that can then be simply and cheaply incorporated into targets to reduce the cost of control.
PMCID: PMC2838779  PMID: 20300513
7.  Impact of Feed Supplementation with Antimicrobial Agents on Growth Performance of Broiler Chickens, Clostridium perfringens and Enterococcus Counts, and Antibiotic Resistance Phenotypes and Distribution of Antimicrobial Resistance Determinants in Escherichia coli Isolates▿  
Applied and Environmental Microbiology  2007;73(20):6566-6576.
The effects of feed supplementation with the approved antimicrobial agents bambermycin, penicillin, salinomycin, and bacitracin or a combination of salinomycin plus bacitracin were evaluated for the incidence and distribution of antibiotic resistance in 197 commensal Escherichia coli isolates from broiler chickens over 35 days. All isolates showed some degree of multiple antibiotic resistance. Resistance to tetracycline (68.5%), amoxicillin (61.4%), ceftiofur (51.3%), spectinomycin (47.2%), and sulfonamides (42%) was most frequent. The levels of resistance to streptomycin, chloramphenicol, and gentamicin were 33.5, 35.5, and 25.3%, respectively. The overall resistance levels decreased from day 7 to day 35 (P < 0.001). Comparing treatments, the levels of resistance to ceftiofur, spectinomycin, and gentamicin (except for resistance to bacitracin treatment) were significantly higher in isolates from chickens receiving feed supplemented with salinomycin than from the other feeds (P < 0.001). Using a DNA microarray analysis capable of detecting commonly found antimicrobial resistance genes, we characterized 104 tetracycline-resistant E. coli isolates from 7- to 28-day-old chickens fed different growth promoters. Results showed a decrease in the incidence of isolates harboring tet(B), blaTEM, sulI, and aadA and class 1 integron from days 7 to 35 (P < 0.01). Of the 84 tetracycline-ceftiofur-resistant E. coli isolates, 76 (90.5%) were positive for blaCMY-2. The proportions of isolates positive for sulI, aadA, and integron class 1 were significantly higher in salinomycin-treated chickens than in the control or other treatment groups (P < 0.05). These data demonstrate that multiantibiotic-resistant E. coli isolates can be found in broiler chickens regardless of the antimicrobial growth promoters used. However, the phenotype and the distribution of resistance determinants in E. coli can be modulated by feed supplementation with some of the antimicrobial agents used in broiler chicken production.
PMCID: PMC2075079  PMID: 17827305

Results 1-7 (7)