Status and the Diversity of Macrobenthos of Udu - Ghievwen Wetlands in the Niger Delta, Nigeria

A survey on the status and diversity of benthic fauna community of Udu – Ughievwen wetlands was carried out for a period of six months. Benthic samples were collected using the Ekman Grab made by Hydrobios. Water Hyancinth (Eichornia crassipes) was also sampled for benthic organisms. A total of twelve taxonomic groups were recorded in this study and they include; Ephemeroptera (37.63%), Diptera (20.45%), Decapoda (14.39%), Odonata (6.48%), Annelida (5.97%), Coleopterans (4.21%) and Trichoptera (3.87%). Others were; Mollusca (3.45%), Amphibian (2.85%), Hemiptera (2.27%) and Arachnida (0.42%). The highest number of individuals was collected from Ohwawha (171) and least at Ofri (60). Shannon – Weiner diversity (H) was highest at Ujevwu and least at Ofri sampling stations respectively. The suitability and diversity of the macrohabitats in the various study sites have favoured the abundance of benthic macroinvertebrates particularly the Decapoda, Ephemeroptera, and Diptera in these water bodies. The dominance of Ephemeroptera in most of the sites indicates a healthy nature or sound environmental quality of the entire Udu – Ughievwen wetlands. The study revealed that wetlands are populated by a rather different assortment of macroinvertebrates. Keywords: Dominant, Wetlands, Macrobenthos, Niger Delta, Biodiversity

Ecological Survey of Macrobenthic Invertebrates of Selected Ponds in Agbede Flood Plain, Southern Nigeria

Ecological study on three selected ponds of Agbede flood plain was fortnightly carried out between January and June, 2007 to assess and document the macrobenthic fauna composition, abundance and distribution, as well as the physicochemical status of some parameters in water which were collected and analyzed monthly.  Benthos was sampled for using the Ekman Grab operated by hand in shallow waters together with the Kick sampling method. Among the eight physicochemical characteristics investigated, pH fluctuated from slightly acidic to slightly alkaline with range of values (5.90 – 7.35) at the studied stations. Significant difference (P<0.05) was observed for biological oxygen demand (BOD5) and dissolved oxygen (DO). A total of ten (10) groups comprising macroinvertebrates taxa with one thousand and thirty one (1,031) individuals were recorded in this study. Most dominant groups were represented by Coleopterans (35.79% and 374 individuals), Hemiptera (20.19% and 211 individuals) and Dipterans (18.47% and 193 individuals).  Evenness was highest in pond 1 (0.4973). The highest number of macroinvertebrates were collected from pond 2 (416) where no human activities occurred and however implied that human activities can rapidly alter any previously stable communities of aquatic environments. Keywords: Ecology, Flood plain, Macrobenthos, Ponds, Fadama, Nigeri

Biodiversity and Environmental Integrity of Some Rivers in Derived Savannah Belt in Edo-North, Southern Nigeria

Investigative study on macroinvertebrates and pollution tolerance index of four rivers in the derived savannah belt of Edo-North in Southern Nigeria was carried out from January to December, 2010. The study involved monthly field sampling and laboratory analysis of macrofauna. The objectives of the study were to evaluate the biodiversity status and importantly, the environmental integrity of the four selected rivers. Two dominant macroinvertebrate families were recorded; Baetidae and Chironomidae while, 53 macroinvertebrate taxa were identified across the rivers. The highest number of species (12) was recorded for Diptera, while, Hirudinea, Nematoda and Arachnida each had 1 species in the population. General diversity indices ranged from 2.02 to 2.78 with the least and highest recorded in Edion and Etuno Rivers, respectively. The fauna evenness index indicated that the water bodies had values less than 1.0. Meanwhile, Pollution tolerance index revealed spatial and seasonal variations in water quality conditions but only Edion River exhibited poor water quality in all the months of study

Screening for Cryptococcal Antigenemia in Anti-Retroviral Naïve AIDS Patients in Benin City, Nigeria Favour Osazuwa

Abstract Objectives: Cryptococcus neoformans is the most incriminated fungal pathogen causing meningitis in acquired immune deficiency syndrome (AIDS) patients, and is known to constitute a major cause of deaths in AIDS patients. This study thus aimed to determine the baseline sero-prevalence of Cryptococcus neoformans infection in anti-retroviral naïve (ART-naïve) AIDS patients using the serum Cryptococcal antigen (crag) detection method. Baseline effect of variation in CD4 counts, as well as sex and age with seropositivity for crag were also determined. Methods: This descriptive cross-sectional study included 150 (61 males and 89 females) ART-naïve AIDS patients attending the Human Immunodeficiency Virus clinic (HIV) at the University of Benin Teaching hospital, Benin City, Nigeria, within the period from February 2011-July 2011. Forty (18 males and 22 females) HIV positive outpatients with CD4 counts >200 cells/ μl who were ART-naive were recruited and used as controls. The sero-prevalence of crag in the patients and the control group was measured using the cryptococcal antigen latex agglutination system (CALAS) (Meridian Bioscience, Europe) and CD4 counts were measured using flow cytometry (Partec flow cytometer, Germany). Results: Of the 150 ART-naïve AIDS patients with CD4 counts ≤200 cells/μL; 19 (12.7%) were positive for serum Cryptococcal antigen. ART-naïve AIDS patients with CD4 count ≤50 cells/μl had the highest prevalence of serum crag. Lower CD4 counts were significantly associated with positivity for serum crag (p<0.001). Age and sex had no significant effect on the sero-positivity for serum crag. One (2.5%) of the controls was sero-positive for crag. Thus, serum crag was significantly associated with AIDS but not with HIV (p<0.001). Conclusion: This study uncovers a high prevalence of crag in ARTnaïve AIDS patients in Benin City. The prevalence of crag was higher in ART-naïve AIDS patients with lower CD4 counts. There is an urgent need to introduce routine screening for crag in ARTnaïve AIDS patients in our locality to reduce the rapid mortality from Cryptococcal meningitis which accounts for a majority of the morbidity factor if undiagnosed during ART therapy

Physico-chemical trends in the sediments of Agbede Wetlands, Nigeria

This study assessed the physico-chemical status of sediments in the Agbede Wetlands with the aim to create a reference archive for the Edo North catchment and to further identify the characteristics mostly influenced by the natural and anthropogenic activities going on at the watershed. Nutrients, zinc, nickel and lead were identified to be mostly of anthropogenic origin, while alkali metals and alkaline earth metals were from both anthropogenic and natural sources. The clustering of stations 1 and 4 indicates that the sediment quality in the lentic systems was not completely excluded from the lotic system, suggesting that principal component analysis (PCA) and cluster analysis (CA) techniques are invaluable tools for identifying factors influencing the sediment quality. The mean values of the particle size distribution were in the following order across the ecosystems: sand (61.86–80.53%) > silt (9.75–30.34%) > clay (7.83–13.89%). The contamination of the water bodies was primarily derived from agricultural run-offs and through geochemical weathering of the top soils. Therefore, our analysis indicates that the concentrations of cations, anions and nutrients in the sediments of the lotic and lentic ecosystems in Agbede Wetlands are not at an alarming level

Screening for Cryptococcal Antigenemia in Anti-Retroviral Naïve AIDS Patients in Benin City, Nigeria

Objectives: Cryptococcus neoformans is the most incriminated fungal pathogen causing meningitis in acquired immune deficiency syndrome (AIDS) patients, and is known to constitute a major cause of deaths in AIDS patients. This study thus aimed to determine the baseline sero-prevalence of Cryptococcus neoformans infection in anti-retroviral naïve (ART-naïve) AIDS patients using the serum Cryptococcal antigen (crag) detection method. Baseline effect of variation in CD4 counts, as well as sex and age with sero-positivity for crag were also determined.Methods: This descriptive cross-sectional study included 150 (61 males and 89 females) ART-naïve AIDS patients attending the Human Immunodeficiency Virus clinic (HIV) at the University of Benin Teaching hospital, Benin City, Nigeria, within the period from February 2011- July 2011. Forty (18 males and 22 females) HIV positive outpatients with CD4 counts >200 cells/µl who were ART-naive were recruited and used as controls. The sero-prevalence of crag in the patients and the control group was measured using the cryptococcal antigen latex agglutination system (CALAS) (Meridian Bioscience, Europe) and CD4 counts were measured using flow cytometry (Partec flow cytometer, Germany).Results: Of the 150 ART-naïve AIDS patients with CD4 counts £200 cells/µL; 19 (12.7%) were positive for serum Cryptococcal antigen. ART-naïve AIDS patients with CD4 count ≤50 cells/µl had the highest prevalence of serum crag. Lower CD4 counts were significantly associated with positivity for serum crag (p<0.001). Age and sex had no significant effect on the sero-positivity for serum crag. One (2.5%) of the controls was sero-positive for crag. Thus, serum crag was significantly associated with AIDS but not with HIV (p<0.001).Conclusion: This study uncovers a high prevalence of crag in ART- naïve AIDS patients in Benin City. The prevalence of crag was higher in ART-naïve AIDS patients with lower CD4 counts. There is an urgent need to introduce routine screening for crag in ART- naïve AIDS patients in our locality to reduce the rapid mortality from Cryptococcal meningitis which accounts for a majority of the morbidity factor if undiagnosed during ART therapy