Parasitological prevalence of bovine trypanosomosis in the Faro and Deo division valley of the Adamaoua plateau, Cameroon

A cross sectional survey to determine the distribution and prevalence of trypanosomosis was conducted in the Faro and Deo division valley, on the Adamaoua Plateau in Cameroon. A total of 334 adult cattle from 5 sedentary herds were examined in 5 villages. Dark field buffy coat method, as well as stained thin blood film examination and packed cell volume (PCV) evaluation were the diagnostic techniques used. The overall prevalence of bovine trypanosomosis in the area was 23%. Among the positive animals, 44 (57.1%), 26 (33.8%), 5 (6.5%) and 2 (2.6%) were due to Trypanosoma congolense, Trypanosoma brucei, Trypanosoma vivax and mixed infection (T. congolense and T. brucei) respectively. The mean PCV of the positive and negative animals ranged between 21.1-27% and 28.2-30.1% respectively. The mean PCV of negative animals (29.1±0.7%) was significantly higher than the mean PCV of positive animals (24.2±2.5%) (P< 0.005). In view of the high risk of trypanosomosis, in the area, an integrated intervention approach to which combines the strategic application of appropriate tsetse fly control methods to reduce host fly contact and chemotherapy and chemoprophylaxis against trypanosomosis is recommended.© 2009 International Formulae Group. All rights reserved.Key words: Adamaoua, Cameroon, Cattle, Prevalence, Trypanosomosis, Tsetse

Prévalence et facteurs de risque de la fièvre aphteuse dans le marché à bétail de Garoua-Boulai et dans la zone de transhumance du Lom et Djerem à l’Est du Cameroun

La fièvre aphteuse (FA) est une maladie transfrontalière qui affecte les ongulés domestiques et sauvages. Elle joue un rôle très important en économie du fait de sa morbidité élevée et de sa restriction du commerce international. En vue de déterminer la prévalence de la FA bovine et les facteurs de risque de transmission de la maladie au marché à bétail de Garoua-Boulaï et dans la zone de transhumance du département du Lom et Djerem à l’Est-Cameroun, une étude rétrospective et transversale a été menée de juin à décembre 2018. Au marché à bétail, l’étude a porté sur l’observation des signes cliniques caractéristiques sur des animaux suspects. Ainsi, 58 bovins atteints de FA ont été identifiés parmi les 614 bovins suspects, soit une prévalence clinique globale de 9,44% (IC95% : 7,13% - 11,76%). Les facteurs internes tels que le sexe n’ont pas influencé la prévalence de la FA. Dans la zone de transhumance, la prévalence rapportée au niveau individuel était de 26,77%. Tous les éleveurs connaissent la FA et ont cité plus de 3 signes cliniques caractéristiques de la maladie. Le fait de considérer la FA comme une maladie mineure, la faible connaissance des sources, des réservoirs et du mode de contamination du virus aphteux par toute la chaine de valeur bovine, expliquent l’endémicité de la maladie dans ces zones.Mots clés : Prévalence, facteurs de risque, fièvre aphteuse bovine, Garoua-Boulai, Lom et Djerem

Changing Ecotypes of Dengue Virus 2 Serotype in Nigeria and the Emergence of Cosmopolitan and Asian I Lineages, 1966–2019

Dengue virus (DENV) is a leading mosquito-borne virus with a wide geographical spread and a major public health concern. DENV serotype 1 (DENV-1) and serotype 2 (DENV-2) were first reported in Africa in 1964 in Ibadan, Nigeria. Although the burden of dengue is unknown in many African countries, DENV-2 is responsible for major epidemics. In this study, we investigated the activities of DENV-2 to determine the circulating strains and to appraise the changing dynamics in the epidemiology of the virus in Nigeria. Nineteen DENV-2 sequences from 1966–2019 in Nigeria were retrieved from the GenBank of the National Center of Biotechnology Information (NCBI). A DENV genotyping tool was used to identify the specific genotypes. The evolutionary history procedure was performed on 54 DENV-2 sequences using MEGA 7. There is a deviation from Sylvatic DENV-2 to other genotypes in Nigeria. In 2019, the Asian I genotype of DENV-2 was predominant in southern Edo State, located in the tropical rainforest region, with the first report of the DENV-2 Cosmopolitan strain. We confirmed the circulation of other non-assigned genotypes of DENV-2 in Nigeria. Collectively, this shows that DENV-2 dynamics have changed from Sylvatic transmission reported in the 1960s with the identification of the Cosmopolitan strain and Asian lineages. Sustained surveillance, including vectorial studies, is required to fully establish the trend and determine the role of these vectors

Assessment of animal African trypanosomiasis (AAT) vulnerability in cattle-owning communities of sub-Saharan Africa

Background: Animal African trypanosomiasis (AAT) is one of the biggest constraints to livestock production and a threat to food security in sub-Saharan Africa. In order to optimise the allocation of resources for AAT control, decision makers need to target geographic areas where control programmes are most likely to be successful and sustainable and select control methods that will maximise the benefits obtained from resources invested. Methods: The overall approach to classifying cattle-owning communities in terms of AAT vulnerability was based on the selection of key variables collected through field surveys in five sub-Saharan Africa countries followed by a formal Multiple Correspondence Analysis (MCA) to identify factors explaining the variations between areas. To categorise the communities in terms of AAT vulnerability profiles, Hierarchical Cluster Analysis (HCA) was performed. Results: Three clusters of community vulnerability profiles were identified based on farmers’ beliefs with respect to trypanosomiasis control within the five countries studied. Cluster 1 communities, mainly identified in Cameroon, reported constant AAT burden, had large trypanosensitive (average herd size = 57) communal grazing cattle herds. Livestock (cattle and small ruminants) were reportedly the primary source of income in the majority of these cattle-owning households (87.0 %). Cluster 2 communities identified mainly in Burkina Faso and Zambia, with some Ethiopian communities had moderate herd sizes (average = 16) and some trypanotolerant breeds (31.7 %) practicing communal grazing. In these communities there were some concerns regarding the development of trypanocide resistance. Crops were the primary income source while communities in this cluster incurred some financial losses due to diminished draft power. The third cluster contained mainly Ugandan and Ethiopian communities which were mixed farmers with smaller herd sizes (average = 8). The costs spent diagnosing and treating AAT were moderate here. Conclusions: Understanding how cattle-owners are affected by AAT and their efforts to manage the disease is critical to the design of suitable locally-adapted control programmes. It is expected that the results could inform priority setting and the development of tailored recommendations for AAT control strategies

Visual Responses of Adult Asian Citrus Psyllid (Hemiptera: Liviidae) to Colored Sticky Traps on Citrus Trees

The effects of five differently-colored sticky traps in capturing adult Diaphorina citri were evaluated in citrus orchards. Trap catches of D. citri were monitored fortnightly on blue, green, red, white and yellow sticky cards placed on three citrus varieties during D. citri active flight period from April to July in south Texas. Evaluation of mean trap catches of each color by repeated measures analysis of variance produced three separate groups: yellow traps caught significantly more D. citri adults than the other four traps; red and green traps caught significantly more D. citri than blue and white traps, which were not significantly different. Although the number of adult psyllid captured on all trap types significantly increased with time during the trapping period, the performance of traps did not change with time. Trap catches were also significantly influenced by the citrus species; traps placed on lemon trees captured more D. citri than those placed on sweet orange and grapefruit, suggesting that plant preference exhibited by D. citri may influence the performance of traps. The ratio of trap reflectance between the 680 to 700 nm and the 450 nm was significantly correlated with total trap catches in all host species studied. Thus, this index was a good indicator of the attractiveness of adult D. citri to colored traps. Additionally, we compared the reflectance values of young versus mature flush shoots of the three host plants used in this study as related to densities of D. citri recorded in colored traps. We discussed the importance of visual cues in the host finding behavior of adult D. citri

Preliminary assessment of bovine trypanosomiasis and its vectors in Santa, Bali and Bafut Sub-Divisions of the, North West Region, Cameroon

A cross-sectional study involving a questionnaire, parasitological examination of cattle and entomological prospection were conducted in the Mezam Division of Cameroon from December 2013 to May 2014 in two seasons for the first time. The objectives were to determine the prevalence of bovine trypanosomiais and its vectors. Peasant farmers ﴾n=95﴿ were interviewed. Standard protocols for parasitological, hematocrit analysis as well as trypanosome identification were used. Acetone baited blue biconical traps ﴾n=5﴿ were used for entomological survey. Questionnaire survey revealed that trypanosomiasis was one of the major health problems affecting animals and a hindrance to agricultural activities. The overall prevalence was 10.3% ﴾31/301﴿. Trypanosome species identified consisted of: T. vivax (58.1%), T. brucei (25.8%), T. congolense (9.6%) and a mix infection (Trypanosoma congolense + Trypanosoma vivax) (6.5%). Vector survey revealed highest fly catch in Bafut subdivision as compared to others with a significant difference ﴾P&lt;0.05﴿. Fly types recorded included: Tabanus 125 (71.4%), Stomoxys 31 (17.7%) and Glossina morsitans submorsitans 19 (10.9%). The overall Apparent Density (AD) was 1.53 fly per trap per day (f/t/d). Therefore, vector transmission and impact of the disease on production is alarming and should not be neglected. Control strategies have to be designed and implemented in Mezam Division in order to eradicate trypanosomiasis and its vectors.© 2016 International Formulae Group. All rights reserved.Keywords: Cattle, trypanosomiasis, Glossina, prevalence, Bafu

Detection of Incipient Pest Infestations on Glasshouse Crops Using Multispectral Imagery and a Common Vegetation Index

Research was conducted to evaluate the effectiveness of multispectral (conventional color and color infrared) imagery and a common vegetation index (simple ratio) for detecting incipient infestations of spider mites (Tetranychus spp.; Acari: Tetranychidae) and false spider mites (Brevipalpus spp.; Acari: Tenupalpidae) on selected crops under glasshouse conditions. Although damaging infestations of both mite species were associated with intense feeding injury which was readily detectable by visual inspection, subtle levels of foliar damage caused by the two mite species were difficult to detect by visual inspection and were not readily distinguishable from undamaged (healthy) foliage in conventional color (CC) or color infrared (CIR) imagery. In contrast, foliage exhibiting subtle levels of mite feeding injury was readily distinguished from healthy foliage in derivative imagery based on the Simple Ratio (SR), a vegetation index defined as the ratio of near-infrared to red reflectance (700-1100 nm and 600-700 nm, respectively) for each pixel in the imagery. CIR and SR images were shown to be considerably more effective than CC imagery in the initial detection and subsequent monitoring of a spider mite infestation on glasshouse cucumbers which increased from incipient to annihilative levels within a period of approximately six weeks. The rationale for and potential uses of CC, CIR, and derivative imagery based on SR and other vegetative indices for monitoring pest infestations on glasshouse crops are discussed

Evaluation of caesarean section practices according to Robson's 10-group classification at a level two maternity ward in Conakry, Guinea

Background: The frequency of caesarean sections (CS) increased dramatically in the world over the last twenty years. The objective of this study was to evaluate caesarean section practices based on Robson classification in an urban referral hospital in Conakry, GuineaMethods: We conducted a cross-sectional study of 2,266 birthing records collected at the maternity ward of the Coronthie Communal Medical Center in Conakry, from January 1st to December 31st 2016. We included in the study all women who had a caesarean section and whose medical records were complete. Robson's classification was used to classify women into 10 groups based on maternal and fetal characteristics. The relative size of each group, its gross caesarean section rate as well as its contribution to overall caesarean section rate and the main caesarean section indications were calculated.Results: In 2016, 769 caesarean sections were performed out of 2,266 deliveries, corresponding to a hospital section rate of 33.9%. Groups 5 (11.0%), 1 (4.8%), and 3 (4.3%) of the Robson classification were the most contributors to registered hospital caesarean section rate. The main indications for caesarean section were uterine scar in group 5 and acute fetal distress in groups 1 and 3.Conclusions: The systematic reference to the Robson classification could help to identify and avoid the relative indications of the caesarean section in urban Guinea. Besides, increasing induction of labor and strengthening providers’ capacities in emergency obstetric and newborn care services could contribute to reduce caesarean section rates in Guinea

Meningococcal Meningitis Surveillance in the African Meningitis Belt, 2004-2013.

BACKGROUND: An enhanced meningitis surveillance network was established across the meningitis belt of sub-Saharan Africa in 2003 to rapidly collect, disseminate, and use district weekly data on meningitis incidence. Following 10 years' experience with enhanced surveillance that included the introduction of a group A meningococcal conjugate vaccine, PsA-TT (MenAfriVac), in 2010, we analyzed the data on meningitis incidence and case fatality from countries reporting to the network. METHODS: After de-duplication and reconciliation, data were extracted from the surveillance bulletins and the central database held by the World Health Organization Inter-country Support Team in Burkina Faso for countries reporting consistently from 2004 through 2013 (Benin, Burkina Faso, Chad, Democratic Republic of Congo, Ghana, Côte d'Ivoire, Mali, Niger, Nigeria, Togo). RESULTS: The 10 study countries reported 341 562 suspected and confirmed cases over the 10-year study period, with a marked peak in 2009 due to a large epidemic of group A Neisseria meningitidis (NmA) meningitis. Case fatality was lowest (5.9%) during this year. A mean of 71 and 67 districts annually crossed the alert and epidemic thresholds, respectively. The incidence rate of NmA meningitis fell >10-fold, from 0.27 per 100,000 in 2004-2010 to 0.02 per 100,000 in 2011-2013 (P < .0001). CONCLUSIONS: In addition to supporting timely outbreak response, the enhanced meningitis surveillance system provides a global overview of the epidemiology of meningitis in the region, despite limitations in data quality and completeness. This study confirms a dramatic fall in NmA incidence after the introduction of PsA-TT