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Background: Vector control of Malaria is mainly made by using impregnated bed nets and insecticides pulverizations indoor or/and outdoor. Besides, appearance and development of resistance’s phenomenon among mosquito populations to insecticides, constitute a significant obstacle this fighting. Aims: To highlighting a neutralization phenomenon of three insecticides (methyl-parathion, dimethoate and cypermethrin) during development of the Anopheles gambiae s.s. larvae. Methodology: Two setups followed one after the other were designed. In setup 1, four concentrations (with four replicates each) were freshly prepared and independently received a first batch of 100 first instars An. gambiae s.s. After emergence of adults from this first batch, the same test media were simply filtered and received a second batch of first instars larvae to make setup 2. Three endpoints were measured in this study: the duration of larval phase, the larval mortality, and the size of adults. Results: The development duration and mortality of larvae decreased significantly at setup 2 with cypermethrin and methyl-parathion. Thus, the duration of larval stage decreased from 10.18 days at setup 1 to 7.84 days at setup 2 for 0.010 µg/l (highest concentration) with cypermethrin and from 10.20 days at setup 1 to 8.27 days at setup 2 for 0.144 µg/l (highest concentration) with methyl-parathion. The larval mortality dropped from 79.32 % at setup 1 to 12.00 % at setup 2 for the highest concentration of cypermethrin and from 76.42 % at setup 1 to 12.50 % at setup 2 for the highest concentration of methyl-parathion. While adults size significantly increased in setup 2. For males, wing’s length increased from 3.28 mm at setup 1 to 3.49 mm at setup 2 for the highest concentration of cypermethrin, from 3.31 mm at setup 1 to 3.49 mm at setup 2 for the highest concentration of methyl-parathion. In female, wing’s length increased from 3.52 mm at setup 1 to 3.68 mm at setup 2 for the highest concentration of cypermethrin, from 3.49 mm at setup 1 to 3.68 mm at setup 2 for the highest concentration of methyl-parathion. Conclusion: This work shows that mosquito larvae, especially An. gambiae are able to modify breeding medium to improve its fitness during their development.

Background: The present work aimed to highlight process of transmission of tolerance to insecticides in An. gambiae population over several generations. Methodology: The experiment was carried out at the laboratory with the strain of An. gambiae that was continuously raised under laboratory conditions for more than five years. The insecticides used during this study belong to three families: methyl-parathion (carbamates), dimethoate (organophosphate), and cypermethrin (pyrethroids). For each insecticide we chose the concentration of insecticide able to exert a selective pressure on An. gambiae without inducing a total mortality. The experiment was done through 12 consecutive generations of An. gambiae s.s. the Endpoints measured: the duration of larval development, larval mortality, and the size of adults. Results: For cypermethrin (pyrethroid) and methyl-parathion (carbamates), the development duration of the larval phase as well as larval mortality decreases significantly from the 7th generation onwards. In the other hand, the size of the adults increases significantly as early as the 5th generation for females especially for cypermethrin and the 7th generation for males. However, with dimethoate, the duration of the larval phase did not vary significantly over the generations. A decrease in larval mortality was noted from the 8th generation but it remained too high. Adult size also increased significantly from the 8th generation onward in both the two genera. This work showed the improvement over generations of certain biological indicators of the resistance. Thus, Conclusion: we can state that resistance appears fairly early in An. gambiae s.s., especially for insecticides that are effective at low doses, such as cypermethrin and methyl-parathion

Aims: This study aimed to investigate the levels of efficacy of anthelmintics that were most commonly used in sheep farms in Nziih locality. Study Design: Longitudinal prospective study. Place and Duration of Study: The study was carried out in Nziih locality in August 2019 and September 2020. Methodology: Resistance against Albendazole (12.5 mg/kg) and Ivermectin (0.2 mg/kg) was evaluated using faecal egg count reduction test in naturally occurring gastrointestinal strongyles of sheep in Nziih. A total of 300 young animals were randomly selected from 5 farms in 2019 and in 2020. Faecal samples were collected from each animal on the first day of treatment (D0) and collected again 14 days later (D14). Faecal Egg Counts were performed using the Willis and Mac Master techniques and resistance was declared when faecal egg count reduction (FECR) was less than 95 % and the lower limit of confidence interval (LCI) less than 90%. Pooled faecal samples for each treatment group were set for D0 and D14 to identify resistant strongyles genera by calculating persistent larval rate (PLR). Results: Resistance against Ivermectin was detected while there was none against Albendazole. Moreover, it was declared only in 2 farms out of the 5 selected. From 2019 to 2020, the status of resistance has shifted from suspicion to resistance for ivermectin and from absence of resistance to suspicion to Albendazole. Resistance was recorded in 2 sites: Pastorale1 (FECR= 85 %, LCI= 42.61 %) and Pastorale 3 (FECR=90.5 %, LCI= 72.26 %) in large flock herds and in farms where sheep were dewormed at least 4 times per year. Trichostrongylus were more persistent than Haemonchus and Oesophagostomum/Chabertia with PLR of 21.22 %, 13.71 %, and 7.40 % respectively. Conclusion: Anthelmintics must be used correctly in conjunction with farmer education in Nziih.

Background: Soil-transmitted helminths (STHs) continue to be a public health problem in developing countries. In Bandjoun, annual deworming is usually administered to school-age children through the national programme for the control of schistosomiasis and soil-transmitted helminthiasis in Cameroon. However, official data on the level of STH infections are scarce in this locality. Methods: We investigated the prevalence and associated risk factors of STHs among children in Bandjoun with the intention to help design future intervention plans. We obtained demographic data and potential risk factors through the interview of children using a structured questionnaire. Stool samples from these children were collected and examined for helminth eggs using Willis’ technique. Results: Three STHs were identified with an overall prevalence of 8.7%. These nematodes were Ascaris lumbricoides (8.3%), Trichuris trichiura (0.3%) and hookworms (Ancylostoma duodenale, Necator americanus) (0.7%). Failure to wash hands before meals (AOR: 2.152 [1.056-4.389]) was the main predictor associated with Ascaris infections. Not eating food picked up from the ground (AOR: 0.494 [0.261-0.937]) and not raising pigs at home (AOR: 0.109 [0.045-0.268]) reduced risk of infection. Conclusion: We recommend that STHs control interventions in Bandjoun focus on the good management of domesticated pigs, the avoidance of contact with soil and handwashing from the earliest ages as a part of daily hygiene practice.

Background: Soil transmitted helminth infections are Neglected Tropical Diseases (NTD) affecting mostly pupils in developing countries. They seem to lose more and more interest due to the fact that resources and research are being justifiably diverted to more recent priorities such as HIV/AIDS, cancers, tuberculosis and malaria. As a result, specific data on STH infections is often lacking. Aims: To evaluate the prevalence and intensities of STH parasites among pupils in Penka-Michel Sub-division, West-Cameroon in order to refresh information for a better management of these parasitic diseases. Settings and Design: A cross-sectional analytic study was conducted from October to December 2018 in Penka-Michel Sub-division. Methods and Materials: To evaluate the prevalence and intensities of STH parasites among pupils, seven hundred and twenty nine (729) stool samples were collected from pupils aged 4 to 14 years old in 23 randomly selected primary schools. The samples were analysed using the concentration method of Willis and the Mc Master technic. Results: Out of 729 pupils enrolled, 107 (14.7%) were infected with one or more STH parasite species. The nematodes species identified were Ascaris lumbricoides (9.9%), Trichuris trichiura (5.3%) and hookworms (2.2%). Pupils aged from 8 to 11 years were the most infected (17.3%). Statistically females were more infected with hookworms (2.2%). These parasites occurred as monospecific (84.11%), bi-specific (13.0%) and tri-specific (2.80%) infections. The mean fecal eggs count was 3652.78±8715.93, 266.67±273.81 and 118.75±72.74 for A. lumbricoides, T. trichiura and hookworm respectively. According to faecal concentration of eggs, 88.18% of infections were light. Conclusion: These results show the necessity of sustainable application of regular deworming, health education and improvements in sanitation among pupils in Penka-Michel Sub-division.

Vernonia amygdalina (V. amygdalina) leaves are commonly used in traditional medicine around the world for the treatment of a plethora disorders, including heart disease. The aim of this study was to examine and evaluate the cardiac effect of V. amygdalina leaf extracts using mouse induced pluripotent stem cells (miPSCs) and their cardiomyocytes’ (CMs) derivatives. We used a well-established stem cell culture to assess the effect of V. amygdalina extract on miPSC proliferation, EB formation and the beating activity of miPS cell-derived CMs. To study the cytotoxic effect of our extract, undifferentiating miPSCs were exposed to different concentrations of V. amygdalina. Cell colony formation and EB morphology were assessed using microscopy, whereas the cell viability was accessed with an impedance-based method and immunocytochemistry following treatment with different concentrations of V. amygdalina. Ethanolic extract of V. amygdalina induced toxicity in miPSCs, as revealed by a decrease in cell proliferation and colony formation, and an increase in cell death at a concentration of ≥20 mg/mL. At a concentration of 10 mg/mL, the rate of beating EBs was observed with no significant difference regarding the yield of cardiac cells. In addition, V. amygdalina did not affect the sarcomeric organization, but induced positive or negative effects on miPS cell-derived CMs’ differentiation in a concentration-dependent manner. Taken together, our findings demonstrate that the ethanolic extract of V. amygdalina affected cell proliferation, colony forming and cardiac beating capacities in a concentration-dependent manner.

Introduction: Gastrointestinal nematodes have a deleterious effect on animal health and production. In search of alternative to synthetic anthelminthics in the control of strongylosis among small ruminants, this study was conducted to evaluate the in situ adulticidal properties of Moringa oleifera on gastro-intestinal strongyles of goats. Methods: Twenty (20) goats naturally infested with mixed gastrointestinal nematodes were distributed into 5 groups (n=4): a negative control group receiving Tween 80 at 2.8%, a positive control group treated with Albendazole at 5 mg/kg and tested groups treated with doses of extract (125, 250 and 500 mg/kg). In situ anthelminthic activity was assessed through determination of the faecal eggs count reduction, total worm count reduction, variation of packed cell volume (PCV) and body weight after treatment. Results: Five species of nematodes were identified among experimental animals, with Strongyloides papillorus as the most prevalent (93.8%) followed by Haemonchus contortus (87.5%). At dose of 500 mg/kg, ethanolic extract of M. oleifera registered 76.4 % and 69.8 % eggs density reduction of gastro-intestinal strongyles eggs and parasitic load nineteen days post-treatment respectively while Albendazole induced 100 % reduction of these same parameters at the dose of 5 mg/kg. Moreover, the extract did not significantly affect PCV nor body weight of experimental goats. Conclusion: This study validates scientifically the use of alcoholic leaves extract of M. oleifera in the treatment of gastro-intestinal strongyles. The standardization of this extract is however necessary for his use as a sustainable tool for controlling strongylosis in small ruminants.

Background In Cameroon, considerable research has been conducted on human ascariasis, but no studies have been undertaken to determine whether pigs contribute to the persistence of the infection in children or to unravel the evolutionary relationship between human-derived and pig-derived Ascaris. Methods DNA was extracted from adult Ascaris worms collected from humans and pigs. Segments of the cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes were sequenced and analysed for 83 worms to dissect the local transmission dynamics of Ascaris in Cameroon. Results The data showed high genetic diversity and revealed demographically expanding populations in the human and pig Ascaris samples. A restricted gene flow between Ascaris lumbricoides and Ascaris suum populations correlating with the preference for humans and pigs, respectively, as hosts was evident. Phylogenetic analyses and haplotype networks split the haplotypes into two major clusters, A and B. However, support for cross-transmission between hosts and hybridization were revealed through shared haplotypes among worms from both hosts. Conclusions This study provides useful baseline information for future studies of the genetics of Ascaris in Cameroon and suggests that effective and sustainable control of human ascariasis should target both human and pig hosts.

Previous studies have reported interactions between Salmonella spp. and some helminth coinfections. In this study, S. typhimurium and Ascaridia galli coinfections were analyzed, and the consequences on therapy were proposed. In a first experiment where the effect of the bacteria on the nematode was evaluated, thirty 42-day-old broiler chickens were divided into 3 groups and coinfected with both parasites. The rate of A. galli egg inoculum was kept constant at 500/ml while that of S. typhimurium varied as follows: T0 (500 A. galli eggs/ml), T104 (500 A. galli eggs/ml+104 S. typhimurium CFUs), and T106 (500 A. galli eggs/ml +106S. typhymurium CFUs). EPG and parasitic load were measured using the McMaster technic, and number of worms and their length were also measured. We observed that T106 containing 106 CFUs of Salmonella significantly reduced the EPG values, and this group recorded the lowest worm load ranging from 18 to 21 worms. Likewise, the length of the worms obtained with T104 and T106 appeared to be shorter than those of the control (T0). In a second experiment to assess the effects of the nematode on the bacteria, thirty 42-day-old broiler chickens were divided into 3 groups and coinfected with both parasites. The rate of S. typhimurium inoculum was kept constant at 106 CFUs while that of A. galli varied as follows: T0 (106CFUs), T500 (500 A. galli eggs/ml +106S. typhymurium CFUs), and T750 (750 A. galli eggs/ml +106S. typhymurium CFUs). Bacterial load was measured using Voogt technique. We observed that T500 increased the colonization time and prolonged the duration of S. typhimurium secretion. Salmonella appears to be a hyperparasite considering the deleterious effect on A. galli. Due to this, it may be prudent to combine anti-Salmonella treatment with anthelmintic so as to effectively treat pathologies caused by these two pathogens.

Background Equine trypanosomiases are complex infectious diseases with overlapping clinical signs defined by their mode of transmission. Despite their economic impacts, these diseases have been neglected by the scientific community, the veterinary authorities and regulatory organizations. To fill the observed knowledge gap, we undertook the identification of different trypanosome species and subspecies naturally infecting horses and donkeys within the Chadian sleeping sickness focus. The objective of the study was to investigate the potential role of these domestic animals as reservoirs of the human-infective Trypanosoma brucei gambiense. Method Blood samples were collected from 155 donkeys and 131 horses in three human African trypanosomiasis (HAT) foci in Chad. Rapid diagnostic test (RDT) and capillary tube centrifugation (CTC) test were used to search for trypanosome infections. DNA was extracted from each blood sample and different trypanosome species and subspecies were identified with molecular tools. Results From 286 blood samples collected, 54 (18.9%) and 36 (12.6%) were positive for RDT and CTC, respectively. PCR revealed 101 (35.3%) animals with trypanosome infections. The Cohen’s kappa coefficient used to evaluate the concordance between the diagnostic methods were low; ranging from 0.09 ± 0.05 to 0.48 ± 0.07. Trypanosomes of the subgenus Trypanozoon were the most prevalent (29.4%), followed by T. congolense forest (11.5%), Trypanosoma congolense savannah (4.9%) and Trypanosoma vivax (4.5%). Two donkeys and one horse from the Maro HAT focus were found with T. b. gambiense infections. No significant differences were observed in the infection rates of different trypanosomes between animal species and HAT foci. Conclusions This study revealed several trypanosome species and subspecies in donkeys and horses, highlighting the existence of AAT in HAT foci in Chad. The identification of T. b. gambiense in donkeys and horses suggests considering these animals as potential reservoir for HAT in Chad. The presence of both human-infective and human non-infective trypanosomes species highlights the need for developing joint control strategies for HAT and AAT.

Worldwide understorey nesting bird species such as bulbuls can also be highly vulnerable to nest predation in disturbed landscapes because they breed mainly on the lower stage of the forest. We test the following hypotheses: the transformation of forests into alternative land use systems and the vegetation’s variables at the nesting sites will affect the understorey nest predation rates. The nests of 12 understorey bird species were surveyed and vegetation variables were measured within five types of habitats along a gradient of increasing forest destruction in the north-eastern peripheral zone of the Korup National Park in Cameroon. Only the open-cup nest type suffers from predation, mostly egg predation. The general linear mixed model analysis suggests that the types of habitat do not affect nest daily predation rate which decreases with increasing trees and understorey plant density. The most deleterious impact of deforestation in this study area is the reduction of nesting sites whose characteristics remain unchanged across the landscape. These results underscore the need to give understorey nesting species, as well as other particularly sensitive groups, special consideration within conservation strategies such as the reduced-impact logging techniques. Key words: Cameroon, deforestation, land-use system, nest predation, understorey birds.

This study was carried out in Korup Region to investigate the reasons for hunting preuss’s red colobus (PRC) in Korup National Park (KNP) Cameroon in order to contribute to its sustainable management. Questionnaires (open and closed end) were used to gather personal information from hunters on different hunting tactics, reasons for hunting PRC and threats to this species in KNP for a period of one month (January 2014). One hundred and eighty-seven hunters responded to questionnaires that were distributed in all 5 villages in the park and 5 other villages randomly selected from the 23 villages surrounding KNP. Excel software was used and all variables were used to calculate relative proportions. Results showed that 53.5% of hunters use shotguns and 46.5% use both shotgun and wire snares in hunting. Majority of the hunters (46%) practice both hunting and farming, 32% practice solely hunting, 18% practice hunting and fishing, and 4% practice hunting, farming and fishing. A large proportion (73.3%) of hunters does hunt PRC for protein and income. However, 45.3% of them do not eat PRC because of its bad odour, and 22% do not eat it because the meat is hard. Hunters in KNP depend on hunting for their survival. Therefore, this calls for conservation action, such as introducing an alternative source of livelihood and protein to hunters, which will help to improve their standard of living and supply protein for their healthy growth, thereby discouraging hunting. Key words: Hunting, Korup National Park, anthropogenic activity, survival, Procolobus preussi.

Additional file 3: Table S3. Concordance between RDT and PCR targeting T. b. gambiense.

Additional file 2: Table S2. Concordance between RDT and PCR targeting all trypanosome species.

Additional file 1: Table S1. Concordance between CTC and RDT.

Eyprepocnemis plorans ibandana is a very common grasshopper species in open environments and agricultural systems of tropical Africa. It is a pest that significantly benefits from forest degradation in southern Cameroon, hence the need to study the bioecology of this subspecies. We studied the reproduction as well as the morphological characteristics and development times of the post-embryonic instars of E. p. ibandana. Sixty-one adult pairs were obtained from sixth instar nymphs caught in grassy vegetation in the Nkolbisson area (Yaoundé) and bred in the laboratory. After hatching, the first instar nymphs were individually placed in cages and fed every two days using fresh leaves of Manihot esculenta. The postembryonic development of E. p. ibandana took six instars in the male and six to seven instars in the female. Mean nymphal development took 79.16 ± 0.51 days in males, 89.93 ± 0.58 days in 6 instar females and 94.96 ± 1.22 days in 7 instar females. The survival rate of the first instar was low (53%). However, from the second instar on the survival rate was very high (> 87%). Sexual dimorphism is distinct in adults, fifth and sixth nymphal instars. Adults of E. p. ibandana took on average 32.57 ± 3.88 days to start mating, and mating lasted 2.12 h on average (1–3 h). Oviposition took place on average 52.03 ± 5 days after first mating; each female deposited one to eleven oothecae with an average of 34.93 ± 2.37 eggs per ootheca. Our study provides important information for the control of this subspecies in southern Cameroon.

Background: Soil transmitted helminth (STH) infections disproportionately affect poor populations in tropical and subtropical parts of the world. They contaminate soil and pupils are mostly at risk of these infections due to their soil related habits. Aims: to assess pupils’ knowledge, attitude and practice in relation to the rate of soil contamination in public primary schools. Methods: Structured questionnaires were administered to 729 consenting participants to obtain information on their awareness status of STH infections. A total of 552 soil samples were collected around toilets, classrooms backyards and playground in 23 public schools randomly selected in Penka-Michel subdivision and examined for the presence of STH eggs using the sucrose flotation method. Results: up to 80% of respondents do not actually know how to avoid getting infected with worms. About 50% of pupils do not actually wash their hands after defecating or wash their fruits/vegetables before eating. Pupil’s nails were mostly untrimmed (74.1%). 77.1% declared they always defecate out of the toilets when they are in school. Out of 552 soil samples examined, 97 (17.6%) were contaminated by Ascaris sp, Trichuris sp, Toxocara sp, Capillaria sp, Cooperia sp, hokworms and Nematodirus sp. Soil from around toilets were significantly more contaminated with Ascaris sp and Trichuris sp eggs. Soil contamination was also significantly associated with absence of water during class hours, unhygienic conditions of toilets, and lack of school perimeter fence. Overall 65% of schools selected showed a low level of hygiene. Conclusion: Pupils of these schools played a major role in the contamination of their environment. Therefore, in order to prevent the STHs transmission cycles in school environment and possibly in pupils, it is necessary to develop specific sustainable intervention programs.

Many microbiotests that have been proposed for use in the risk assessment of environmental pollutants have the drawback of lacking relevant published data on various aspects of their test application possibilities and therefore do not receive the regulatory recognition which they may deserve. The MARA bioassay lacks published data for many relevant environmental pollutants, particularly pesticides and this may limit its use in regulatory framework. The present study has assessed the sensitivity of the MARA bioassay relative to other established bioassays (Daphnia magna and Oreochromis niloticus) to two widely used herbicide formulations: Roundup (having glyphosate as active ingredient) and Herbextra (with the active ingredient being 2,4-dichlorophenoxyacetic acid-2,4-D). Roundup was found to be more toxic than Herbextra in all three bioassays. The D. magna EC50 s obtained for Roundup and Herbextra were respectively 5.55 and 356.61 mg/l while the LC50 s for O. niloticus were 11.30 and 222,28 mg/l respectively. In the case of the MARA bioassay microbial toxic concentrations (MTCs) for individual species ranged from 6.85 to 468 mg/l with an overall mean MTC of 101.82 mg/l for glyphosate and from 74.67 to 13,333 mg/l for 2,4-D giving an overall mean MTC of 2855.88 mg/l. Although the overall MTCs from the MARA bioassay were much higher than the LC50 s and EC50 s from the fish and daphnia bioassays respectively, the most sensitive MARA organism for each of the herbicides had MTCs that were comparable to or lower than the corresponding endpoints from the other bioassays implying that the MARA assay is a potentially useful bioassay for risk assessment of pesticides.

Haemonchus contortus is a blood-sucking abomasal helminth of small ruminants responsible for major economic losses to small farmers worldwide. Widespread resistance to synthetic anthelminthics has stimulated a need for alternative strategies of parasite control, among which is the use of medicinal plants with natural anthelminthic properties. This study assessed in vitro the efficacy of infused and macerated aqueous extract as well ethanolic extract of Moringa oleifera against fresh eggs, embryonated eggs, L1 and L2 larvae of H. contortus. For this purpose, five different concentrations (0.625, 1.25, 2.5, 3.75 and 5 mg/ml) were prepared from dry extracts via serial dilutions with distilled water. Fresh eggs obtained from artificially infected goat feces were exposed to these different concentrations for 48 hours, while embryonated eggs and larvae were exposed for 6 and 24 hours respectively. Distilled water and 1.5% DMSO were used as negative control. The results were expressed in terms of mean inhibition percentage of egg embryonation, mean inhibition percentage of egg hatch and mean percentage of larval mortality. An overview of results revealed that ethanolic leaf extract of M. oleifera was most efficient on eggs by inhibiting 60.3% ± 8.2% and 92.8% ± 6.2% eggs embryonation at 3.75 and 5 mg/ml respectively with a significant difference (P 0.05), which contributed to obtaining the lowest LC50 value of 0.985 mg/ml. This extract also inhibited 99% ± 2% egg hatching of H. contortus at 5 mg/ml with an LC50 value of 1.7 mg/ml. Concerning activity on larvae, the ethanolic extract was also most potent against them by inducing 98.8% ± 2.5% and 100% ± 0% mortality of L1 and L2 larvae at 5 mg/ml respectively. Infused aqueous extract was more efficient on eggs than on larvae with an IC50 value less than 2 mg/ml and an LC50 value more than 3.5 mg/ml. Macerated aqueous extract showed good activity against the four developmental stages with LC50 values ranging from 2.08 mg/ml for L2 larvae to 2.92 mg/ml for L1 larvae and 2.37 to 2.52 mg/ml for embryonated and fresh eggs respectively. The current study showed that all three extracts of M. oleifera tested possessed potential ovicidal and larvicidal activities against H. contortus. However, further in vivo studies are necessary to validate the anthelminthic property of this plant.

Background: There is a paucity of knowledge on the epidemiology of parasitic diseases which remain rampant in the Dschang municipality. Three communities around Dschang town—Ngui (slummy), Paidground (heterogeneous) and the Administrative Quarter-AQ (wealthy) were investigated to highlight the aetiology of intestinal parasitic infections (IPIs) in children in order to enhance health policy intervention priorities. Methods: Between July and November 2009, 31 stools amples were collected from children aged six months to 18 years (mean 9 years) in 295 house-holds across the three communities. A structured questionnaire was used to obtain information on socio-demographic characteristics, source of water supply, de-worming practice and treatment history. Stool samples were screened for ova/larvae of intestinal parasites using direct wet mount, brine floatation and formol-ether sedimentation methods. Results from stool tests and information obtained from questionnaires were analyzed using SPSS. Results: In total, 223 (26.8%) children had single (19.9%) and multiple (7%) infections from seven parasites: the overall prevalence was 34.7%; helminthes 19.3% and protozoa 15.4% (χ2 = 4.3, P Entamoeba histolytica 8.8%, Ascaris lumbricoides 7.5%, Trichuris trichiura 6.8%, Entamoeba coli (5.8%), hookworm 4.6%, Giardia lamblia 0.8% and Vampirolepis (Syn: Hymenolepis) nana 0.4%. Infections were more severe and rates significantly higher in Ngui (45.9%, χ2 = 86.83, P 2 = 111.97, P < 0.0001). Conclusion: Regular sustained synchronized deworming alongside antiprotozoaics, periodic diSagnostics for all children and slummed residents which lend to intestinal protozoa; sanitary inspection of homes and water supplies; adequate drainage and community wastes disposal; and prevention education on hygiene, sanitation, safe water and health were desirable.

Avec la deforestation croissante dans les zones tropicales, les bulbuls comptent parmi les especes d’oiseaux les plus vulnerables en raison de la perte des sites de nidification dans les habitats fortement perturbes. La presente etude vise a evaluer le niveau de predation des nids de deux especes de bulbuls Eurillas latirostris et Eurillas virens suivant les types d’habitats (forets naturelles et habitats perturbes) et les phases de nidification. Dix-neuf nids actifs des bulbuls verdâtres ( Eurillas virens ) et 13 nids de bulbuls a moustaches jaunes ( Eurillas latirostris ) ont ete localises et les incidences de predation ainsi que les parametres lies a la reproduction de ces oiseaux ont ete enregistres pendant leur periode de nidification a la peripherie Nord-Est du Parc National de Korup. L’etude revele que la predation est la principale cause d’echec de nidification chez ces especes et affecte plus de 50% de nids. Les types d’habitat n’ont pas d’influences significatives sur les differents taux de predation. Parmi les variables de la vegetation, la surface terriere influence positivement le taux de predation quotidien des nids de Eurillas latirostris pendant que la hauteur maximale du couvert vegetal au-dessus du nid influence negativement le taux de predation quotidien des nids de Eurillas virens . Globalement, les deux especes ont ete relativement plus vulnerables a la predation pendant la phase d’incubation. Ces resultats soulignent la necessite d'accorder une attention particuliere aux bulbuls, ainsi qu'a d'autres groupes particulierement sensibles a la destruction des forets tropicales humides, dans le cadre de l’elaboration des strategies de conservation qui promeuvent la reduction des impacts d'exploitation forestiere. Mots cles : Cameroun, Eurillas latirostris, Eurillas virens , Foret naturelle, Habitats perturbes, Predation des nids.

Widespread extensive and improper application of pesticides may pose risk to aquatic ecosystem and affect non-target organisms. This study aimed at assessing chemical pollution with pesticides using the PRIMET (Pesticides Risks in the tropics to Man, Environment and Trade) model in the Benoe stream. Ecotoxicological data on pesticides, pesticide and water physico-chemistry were used as input parameters. Water parameters were measured monthly for 06 months in 08 sampling points along the stream. Pesticide characteristics were obtained from the Pesticides Properties Data Base (PPDB) and the PRIMET software. The risk assessment was done for 44 active ingredients used in the area and whose ecotoxicological and physico-chemical data were available. Water parameters significantly (p100), seven to pose an acute possible risk (1≤ETR≤100) and 28 to pose no risk (ETR

We conducted a study to assess the impact of peri-urban agricultural activities of the city of Dschang on the water quality and macroinvertebrate structure of the Menoua stream. This study covered 3 stations (one reference station at the upstream of the peri-urban agricultural activities and two downstream) with a monthly sampling frequency from March 2015 to February 2016. The physico-chemical analysis were carried out according to standard protocols while the benthic macro-fauna was harvested using a haze net of 30 cm side and 400 μm mesh size. Physico-chemical parameters such as temperature, pH, conductivity, TDS (Total Dissolved Solids), salinity, turbidity, colour, SS (Suspended Solids), nitrate, ammonium and orthophosphate were analyzed. The inventory of benthic macroinvertebrates revealed a taxonomic richness of 42 families and 77 taxa and a gross abundance of 1833 individuals. Spatio-temporal monitoring of physicochemical and biological parameters provided the image of relatively low pollution. Metrics such as total taxonomic richness, richness of ETO (Ephemeroptera-Trichoptera-Odonata), relative abundance of Ephemeroptera-Trichoptera-Odonate (% ETO), diversity of Shannon and Weaver and Pielou's equitability were determined at each of the three stations. These indices, unlike several other studies, increased downstream of anthropogenic activities. Low agricultural activity in the watershed has resulted in habitat diversification and availability of resources for benthic macroinvertebrates, resulting in increased abundance and diversity

The impact of wastewaters from the Toutsang sandpit (Dschang), both on water parameters and on benthic macro-invertebrate community structure of the Doulahang stream was studied from March 2015 to February 2016 on a monthly basis in three sampling stations named TS1, TS2 and TS3. The physico-chemical analysis were carried out according to standard protocols while the benthic macro-fauna was harvested using a haze net of 30 cm side and 400 μm mesh size. The analysis of physico-chemical parameters revealed that the introduction of wastewater from the sandpit at the TS2 station led to an increase of the temperature, conductivity, total dissolved solids, salinity, suspended matter, turbidity and colour. The wildlife inventory identified 63 taxa divided into 4 phyla, 6 classes, 13 orders and 31 families. The lowest values of the taxonomic richness (18 taxa, against 46 taxa and 47 taxa respectively to stations TS1 and TS3), the Shannon diversity index (2.48 bits / ind.) and the Pielou's evenness (0.62) were observed at station TS2 which received wastewaters from the sandpit. Similarly, the low values of the richness and abundance of the pollutionsensitive groups (Ephemeroptera-Trichoptera-Odonata) were recorded in this station. Significant negative correlations were found between some metrics (total taxonomic richness, taxonomic richness of the Diptera, Richness of Ephemeroptera-Trichoptera-Odonata, Taxonomic richness of insects, Relative abundance of Ephemeroptera-Trichoptera-Odonata, Shannon Weaver diversity index, Pielou's evenness) descriptors of the structure of benthic macro-fauna communities and physico-chemical parameters indicative of physical pollution such as turbidity, suspended matter and colour.

Pesticides are widely used to reduce crop losses due to pests. This study (an initial part of a project on risk assessment and biomonitoring) deals with pesticide use patterns in the South-West, Cameroon. This descriptive and cross-sectional study was done using questionnaires randomly administered to 137 respondents. Twenty-one crops were recorded in the area with a total of 107 pesticides (60 active ingredients) used. Three illegally used pesticides were recorded (lindane, dimethoate and malathion). Application of pesticides in combination was quite common (42.3%). Pesticide application was mainly manual using a sprayer (96.4%) with 54% of users experiencing health problems post-application. Because of the lack of funding and training, 19.7% sprayed pesticides without protection. For the Restricted Entry Interval (REI), 43.1% entered the field in less than 12h after pesticide application. The correlation between the REI and the number of symptoms was negative and non-significant (R=-0.07, p≥0.05). The main place to store pesticides was the house (57.7%) with the exception of CDC where pesticides were kept in a pesticide store. Some respondents (54.7%) said they hadn’t received any training on pesticide application while 20.4 % of respondents failed to follow recommended doses. Surface water around farms was used by 62.1% of pesticides users for domestic purposes. Some farmers (46.7%) have once heard about pesticide related accident while 14.6% suffered from pesticide intoxication, the prevalence being significantly higher in males (p

Objective: The aim of this study was to evaluate the in vitro activity of aqueous and methanolic extracts of Cassia alata leaves on the development of Plasmodium falciparum field isolates. Method: The Trager and Jensen method with slight modifications was used. For the culture, RPMI 1640 and Albumax were used to replace human serum. The extracts as well as the reference drug (chloroquine) were diluted using RPMI medium. The P. falciparum field isolates were incubated with 8 concentrations ranging from 128 to 1 μg/ml in a 96-well microplate and incubated for 48 h in a candle jar. RPMI and 1% DMSO were used as negative controls. Result: The extraction yields of C. alata were 7.96 and 13.23% for aqueous and methanolic extracts respectively. RPMI and DMSO didn’t have any harmful effect on the growth of P. falciparum. On the other hand, in the wells treated with extracts of C. alata leaves, inhibition of P. falciparum growth was registered with increasing concentrations of extracts. The inhibitory effect of the methanolic extract was stronger and we obtained the maximum mean inhibition rate of 100 ± 0.00% and 99.87 ± 0.62% at the concentrations 128 and 64 μg/ml respectively. As for the aqueous extract, it yielded a mean inhibitory rate of 99.2 ± 0.76% at the concentration of 128 μg/ml. Given the IC50 obtained that is 0.48 ± 0.02; 0.67 ± 0.11 and 0.77 ± 0.08 μg/ml for methanolic extract, aqueous extract and chloroquine respectively. The extracts of C. alata may be classified as active. This activity may be due to the presence of terpenes and tannins in the extracts.

Helminths are soil transmitted nematodes with life cycles that involve no intermediate host or vector and are among the most prevalent of chronic human infections worldwide. The main aim of this study was to determine the prevalence and intensity of infection of gastrointestinal helminths among inmates in the Bamenda Central Prison, Mezam Division, North West Region of Cameroon. Three hundred and ninety three (393) stool samples were collected from (385 males and 8 females) inmates aged 16 to 84 years in 14 Cells inside the prison between a period of September 2014 and February 2015. Qualitative and quantitative analysis of stool samples were carried out using the Flotation and McMaster techniques respectively. Of the 393 number of stool samples examined, 27 (6.87%) persons were positive with at least one helminth infection. From the results obtained, three species of nematodes were detected with a prevalence rate of 5.08% for Necator americanus (Hookworm), 1.27% for Ascaris lumbricoides and 0.51% for Trichuris trichiura. Out of the 385 stool samples collected from males, 26 (6.61%) were positive for nematode infections. Amongst females, only one had a nematode infection with a prevalence rate of 0.26%. The mean intensity for Necator americanus, Ascaris lumbricoides and Trichuris trichiura was 370±611.81, 130±115.11 and 75±35.35 egg per gram of faeces respectively. The degree of infection was light for both Ascaris lumbricoides and Trichuris trichiura, and moderate for Necator americanus. The trend of infection was low in Ascaris lumbricoides and Trichuris trichiura, but high in Necator americanus. The prevalence of these parasites was very high in cells A and B than in the other cells. Multiple infections were more common amongst the inmates than single infections with the older inmates more infected than the younger ones. These results showed that gastrointestinal helminths vary in relation to different Prison cells and age of the inmates. There should therefore be need to educate the prison population on Health education and practice of hygienic habits, in order to fight effectively against these diseases in the inmate community.

Helminth infections, such as Ascaris lumbricoides, Trichuris trichiura and Hookworms are major public health concerns. The aim of this study was to evaluate the prevalence and intensity of infection of gastro-intestinal helminthiasis in Babadjou. Qualitative and quantitative analyses were carried out on eight hundred and twenty five (825) stool samples collected from residents using the simple centrifugal flotation and McMaster count technique respectively. Out of the 825 samples examined, 70(8.5%) were infected with at least one helminth parasite with prevalence and intensities of infection of 4.4% and 2594.44 ± 3897.17 for A. lumbricoides, 4.2% and 72.86 ± 110.04 for T. trichiura, 1.9% and 83.33 ± 72.37 for Hookworms and 0.2% and 50 ± 00 for Capillaria hepatica respectively. Males (13.8%) were more infected than females (8.6%). The prevalence of A. lumbricoides and T. trichiura vary significantly with age groups with those of 1-10 years taking the lead (17.9%). The prevalence between the three educational levels differed significantly (P < 0.05) for A. lumbricoides, T. trichiura and Hookworm where those from the primary level were most infected (28.6%). The locality of Bamedji showed very high prevalences of A. lumbricoides (35.7%) and T. trichiura (17.9%) with significant differences as well. From the different occupations involved in the current study, students harboured all the four nematodes encountered. Cases of double and triple infections were recorded with A. lumbricoides+ T. trichiura (2.4%) being the highest and A. lumbricoides+ T. trichiura+ Hookworms (0.2%) the only triple infection registered. According to fecal concentration of eggs, 77.01% of infections were light infections, 3.44% moderate and 19.54% heavy infections. Only A. lumbricoides had heavy infections while all Hookworm infections were light. The results found on this study show that, it is important to control and prevent gastrointestinal helminths in and around Babadjou.

Acute and sub-acute toxicity of ethanolic extract (ETE) of C. mannii was assessed on white mice (Mus musculus). After 48 h of extract administration, no death was registered. It was deduced that the LD50 was indisputably higher than 16 g/kg body weight. The sub-acute toxicity test was based on the daily administration of three doses of ETE (300, 600 and 1200 mg/kg body weight) for four weeks; 1% DMSO served as negative control. As for the first experiment, no sign of toxicity was registered. Conversely, the sub acute doses stimulated and increased the weight-rate of mice after 7 days of treatment. Except for the spleen weight, the doses administrated did not modify the weight index. It was observed that, subacute doses induced and increased (a) the food (particularly) and water consumption according to time and (b) the number of red and white blood cells. It was thought that, ETE can stimulate the haematopoietic function. Finally, no time variation of the activity of alanine aminotransferase and aspartate aminotransferase enzyme was observed in the serum of euthanized mice. The results showed the innocuity of ETE of C. mannii and thus validated his utilization in cameroonian traditional pharmacopoea.

Objective To assess ovicidal activity of three acetonic extracts from the leaves of three forage legume, Calliandra calotyrsus (C. calotyrsus) , Gliricidia sepium (G. sepium) and Leucaena diversifolia (L. diversifolia) in vitro on Haemonchus contortus (H. contortus) . Methods Eggs were exposed for 24 hours to five different concentrations (0.075, 0.15, 0.3, 0.6 and 1.25 mg/mL) of acetonic extracts at room temperature (24 °C). Distilled water and 0.4% Tween were used in the bioassay as negative controls. Results The later did not affect embryonation and egg hatching of H. contortus. Conversively, significant effects were obtained with the acetonic extracts of leaves of all three plants and the maximum activity was observed with the highest concentration (1.25 mg/mL). The acetonic extract of G. sepium was found to be more active (2.9% and 0.0% for embryonation and egg hatching, respectively) than the other substances 16.5% and 33.5%, respectively for C. calothyrsus , 33.7% and 33.3%, respectively for L. diversifolia . Conclusions These results suggest that the three forage legumes do possess ovicidal properties and further studies on larvae should be carried out.

The nematicidal activity of ethanol extract (ETE) of Canthium mannii (Rubiaceae) was assessed in vivo compared to that of Mebendazole on the adult of Heligmosomoides polygyrus parasite of rodents. One hundred and five Swiss white mice of two sexes aged 5-6 weeks old, and weighing between 20 and 25 g were orally infected with a 0.8 ml of a dose of 104-120, 1-week-old H. polygyrus infective larvae (L(3)). After the pre-patent period (9-11 days), infected animals were randomly divided into 7 groups of 15 animals each. The nematicidal efficacy of the ETE was monitored through faecal egg count reduction (FECR) and total worm count reduction (TWCR). Five doses (350, 700, 1400, 2800 and 5600 mgkg(-1) body weight) for ETE and 22 mgkg(-1) for Mebendazole were studied using a bioassay. Mebendazole and 3% dimethylsulfoxide (DMSO) were included in the assays as reference drug and placebo, respectively. Each host received according to its weight for 7 days a daily dose of 0.7ml of the product. The ETE for all the doses tested except the dose rate 350 mgkg(-1)bwt was active in vivo on the adult of H. polygyrus and reduced significantly (p0.05) the FEC and the TWC of the nematode. The dose rate 5600 mgkg(-1)bwt showed the highest nematicidal activity of 75.0% FECR and 83.6% TWCR 7 days post-treatment. These results supported the possible use of medicinal plants in the control of gastro-intestinal helminthiasis.

Preuss’s red colobus is critically endangered and endemic to Cameroon and Nigeria. It is one of the least studied red colobus species and therefore further knowledge about the species is crucial for conservation work. Activity budget of Preuss’s red colobus was carried in the southern part of Korup National Park, South West region of Cameroon for 18 months and was aimed at contributing to the understanding of the species general behavioural pattern for conservation. Time interval scan sampling method was used for this study. Two thousand three hundred and three individual observations were recorded from 273 group scans for 462 hours. Results revealed general activity time budget for the species, activity related to seasonality, period of the day and age class. In general, this species spent 1: 1: 1: 4: 2 resting, feeding, moving, others and socializing respectively. In wet season they spent more time in all the activities 1: 1: 1: 1: 4 resting, moving, feeding, other and socializing respectively more than in the dry season. Their activity budget within a day revealed the following results: feeding 9: 7: 6 afternoon, morning, mid-day respectively, moving 1: 1: 4 mid-day, morning, afternoon respectively, resting 1:1:2 mornings, mid-day and afternoon respectively, socializing 4: 1:0:2 mornings, mid-day, afternoon respectively and other 1: 1: 3 morning, mid-day, afternoon respectively. Results on the activity budget of age class indicate that adults spent more time feeding (16.31%), resting (25.72%), moving (13.09) than juveniles and infants but infants spent more time socializing (5.55%) than adults (1.58%) and juveniles (00%). This study therefore gives a basic clue of activity budget of Preuss’s red colobus, specific for Korup National Park, experiencing human threat. This information can play an important part for the proper management and conservation of this species. © 2015 International Formulae Group. All rights reserved. Keywords: Behavioural patterns, red colobus, conservation, scan sampling, seasonality, time period

Vepris louisii Gilbert, used by indigenous farmers to treat helminth infections in livestock, was screened in vitro for anthelmintic activity using free living stages of laboratory mouse hookworm, Heligmosomoides bakeri. Aqueous and organic (methanol/dichloromethane) extracts were used for egg hatch assay, while only organic extract was used for larval mortality assay. Significant effects have been observed on three (eggs, L1 and L2 larvae) of the four stages tested, with the organic extract being more effective than aqueous for egg hatch assay. Effects were dose dependent for egg hatch, and both dose and time dependent for larval mortality. The infective stage was the least susceptible. Albendazole, was not significantly different (p>0.05) from plant extract at the highest tested concentration (5000 μg/ml) on all larval stages. Vepris louisii showed promising anthelmintic properties.

The development of parasitic resistance vis-a-vis conventional anthelmintics, and the relatively high cost of available anthelmintics have limited the efficiency of gastro-intestinal helminth control and thus, created an interest in studying medicinal plants as an alternative means of parasitic control. The aim of this study was to assess the ovicidal and larvicidal activities of aqueous and ethanolic extracts of leaves of Bidens pilosa on eggs (fresh and embryonated), first and second larval stages of Heligmosomoides bakeri. In order to achieve this objective, the extracts were diluted in distilled water to obtain five different concentrations: 625, 1250, 2500, 3750 and 5000 μg/ml. Fresh eggs obtained from artificially infected mice feaces, embryonnated eggs and larvae (L1 and L2) were exposed to these different concentrations for 48 hours, 6 and 24 hours respectively. Distilled water and 1.5% DMSO were used as negative controls in the bioassay. In fact, distilled water and 1.5% DMSO had no effect on embryonnation, hatching and larvae survival. Contrarily, extracts of B. pilosa showed concentration dependent activities. At 5000 μg/ml, ethanolic extract inhibited 82.2% embryonic development of fresh eggs and induced 66.4% mortality of L2 larvae. In a similar study, the infused extract inhibited hatching by 95.6% of embryonnated eggs and induced the mortality of 68.9% L1 larvae. These results showed the ovicidal and larvicidal properties of B. pilosa and indicate that, this medicinal plant can be a focus for the research of new source of anthelmintics.

The use of synthetic anthelminthics is confronted with the development of resistant strains, high cost and unavailability. Available local resources which are efficient and less expensive are an alternative to the limits of these anthelminthics. This study evaluated the ovicidal and larvicidal efficacy of aqueous and ethanolic extracts of Nauclea latifolia. The eggs of the parasite were obtained from faeces of artificially infected mice, and after 3 and 4 to 5 days incubation at 25°C, L1 and L2 larvae were obtained respectively. The different stages were exposed to 5 concentrations and exposition periods were 48 and 24 hours for eggs and larvae respectively. Distilled water and 1.5% dimethylsulfoxide (DMSO) were included in the assay as negative control for aqueous and organic extract respectively. The aqueous and ethanolic extracts of N. latifolia had a negative effect on development of embryo, hatching rate and larval survival of Heligmosomodes bakeri. At the concentration 5000 μg/ml, the embryonation rate of 62.7, 21.7 and 17.4% were obtained respectively for hot, cold water and ethanolic extract. 22.4, 18 and 14.5% hatching rate were obtained with hot, cold water and ethanolic extract at 5000 μg/ml. The mortality rate of L1 for the high concentration was 77.3, 89.3 and 73.9% for hot, cold water and ethanolic extract respectively while for L2 larvae, 82.7, 77.5 and 83.3% mortality rate were obtained respectively with hot, cold water and ethanolic extract. These in vitro results suggested that extracts of N. latifolia possess ovicidal and larvicidal properties. Further experiment incorporating in vivo and toxicological studies is required.