Multiple filarial species microfilaraemia: a comparative study of areas with endemic and sporadic onchocerciasis

Background & objectives: The study was aimed at determining the pattern of co-occurrence of species ofmicrofilaraemia between onchocerciasis endemic and sporadic populations.Methods: From every consenting person of one year and above, 50 μl of day and night blood samples werecollected and processed respectively with Haemotoxylin and Giemsa as vital stains. Two skin snips (one eachfrom the waist and the shoulder) were also taken from these individuals and processed.Results: Results showed single species microfilaraemia (86.4 and 82.3%), double species microfilaraemia (12.2and 16.9%) and triple species microfilaraemia (1.4 and 0.7%) for endemic and sporadic populations respectively.All the species had single species microfilaraemia mostly, but Mansonella perstans and Loa loa showed greatestt endency towa rds doubl e and t r ipl e spe c i e s mi c rof i l a r a emi a . The pr eva l enc e of Wuche re r ia banc rof t imicrofilaraemia among those positive for Onchocerca volvulus was significantly lower than the overall prevalenceof Wuchereria bancrofti. Wuchereria bancrofti microfilaraemia was most common among those who had L. loamicrofilaraemia. Wuchereria bancrofti microfilarial intensity was higher among those with M. perstansmicrofilaraemia than among those positive for any of the other filarial species. Similarly, the intensity of M.perstans microfilaraemia among those positive for W. bancrofti exceeded the overall intensity of M. perstans.Conclusion: It is concluded that there was no definite pattern in mf densities discernible from co-occurrenceinfections either in the onchocerciasis endemic or sporadic population. There could be varied outcomes ofonchocerciasis infection attributable to positive or negative regulatory effects of other pathogens harbored bythe victims

Impact of Physico-Chemical Factors of Contaminated Foci on the Survival of Geohelminths in Abua Communities, Niger Delta Nigeria

Physio-chemical analysis of 200 soil samples collected from contaminated foci was investigated in six communities of Abua, Niger Delta Nigeria. The Jackson’s method was used in the chemical analysis of contaminated soils while Cobb’s decanting and sieving method was used in the extraction of geohelminths. The  data showed that temperature, pH, Calcium (Ca2+), magnesium (mg2+), potassium (k+) ions and electrical conductivity had much effect on the survival of  eggs and larval development of geohelminths. It was also observed that the nature of the soil in the study communities was clay-loam and sandy-loamy. The continuous deposition of human faeces in these contaminated foci should be discouraged. This can be achieved by the construction of toilet facilities of whatever description in the study  area by the government. @JASEMJ. Appl. Sci. Environ. Manage. December, 2010, Vol. 14 (4) 117 - 12

Bio-survey of Plankton as indicators of water quality for recreational activities in Calabar River, Nigeria

With the increasing recognition of Calabar as a global tourist destination, the suitability of Calabar River for recreational activities by tourists was investigated. The aim was to use phytoplankton and zooplankton characteristics to assess the water quality of the Calabar River. Phytoplankton and zooplankton samples were collected from four stations along the river and carried in plastic containers at 4oC to the laboratory for taxonomic and diversity index analyses. Water samples were also collected from the sampling stations for physico-chemicalanalysis. In total, 331 phytoplankton individuals were identified from sixty-six species in sixty genera and six taxonomic groups. The most abundant taxon was Bacillariophyceae 212 (64.05%), followed by Cyanophyceae 42 (12.69%), Chlorophyceae 40 (12.08%); Dinophyceae 16 (4.83%); Chrysophyceae 12 (3.63%) and Xanthophyceae 9 (2.72%). Similarly, the diatoms were highest in species richness (54.55%) followed by Cyanophyceae (18.18%),Chlorophyceae (12.12%), Dinophyceae (6.06%), Chrysophyceae (4.55%), and Xanthophyceae (4.55%). Among the zooplankton, the Copepods were the most abundant (54.89%). Others were Protozoa (14.13%), Polychaeta larvae (7.07%), Cyclopoida (5.43%), Cladocera (5.43%), Arthropoda (4.89%), Ostracoda (3.26%), Rotifera (2.72%),Malacostraca (1.09%), and Foraminiferida (1.09%). The copepods were highest in species richness (13), representing 36.11% of the total. The other zooplankton taxonomic groups were Protozoa (16.67%), Cyclopoida (11.11%), Ostracoda (8.33%), Rotifera (8.33%), Cladocera (5.56%), Malacostraca (5.56%), Arthropoda (2.78%), Polychaeta larvae (2.78%), and Foraminiferida (2.78%). We did not observe any preponderance of harmful phytoplankton or zooplankton in the Calabar River during the study. The river showed no evidence of stress beyond her carrying capacity, and there was no evidence of any harmful environmental conditions that is detrimental to recreational activities in the Calabar River. We assess Calabar River as being biologically suitable for contact recreational activities, from the point of view of her plankton characteristics

Population dynamics and gillnets selectivity of Chrysichthys nigrodigitatus (Lalepede 1803) in lower reaches of the Cross River estuary, Nigeria

Population Dynamics and gillnet selectivity of Chrysichthys nigrodigitatus (Lalepede 1803) in the lower reaches of the Cross River estuary of Nigeria was studied for two years (January 2008 – December 2009), with respect to selectivity, gillnet sizes and population of the species based on length frequency analysis. Estimates of growth parameters, asymptotic length (L∞) = 98.25cm and growth constant (K/year) = 0.96yr-1. Total mortality rate (Z) was 6.27 yr-1, natural mortality (M) = 1.22 yr-1, Fishing mortality (F) = 5.05 yr-1 and Exploitation rate (E) = 0.81. Significant correlation (r = 0.9140 – 0.9770 and r = 0.976 – 0.977). (P < Z0.05) was observed between mesh sizes of gillnets and mean values of the morphometric characteristics (such as half-circumference, total length and total weight) of the fish. There is low percentage frequency range of the number of fish caught in different mesh sizes, possibly with low hanging coefficient range (0.4-0.5). Gilling, snagging, wedging, entangling were observed in the selection of the fishes. In conclusion, selectivity in Chrysichthys nigrodigitatus gillnet fishery in the Cross River estuary may be moderately adequate despite the influence of several other factors. The selection distribution curve using 17.5cm estimated modal total length recommends the usage of 50mm mesh size and above for exploitation of the species.Keywords: Gillnet, Selectivity, Mortality, Length, Populatio

Relationships between Onchocerca volvulus microfilaraemia and the clinical manifestations of meso-endemic onchocerciasis in the Umuowaibu and Ndiorji communities in southeastern Nigeria

The study was aimed at determining the relationship between Onchocerca volvulus microfilaraemia and the clinical manifestations of onchocerciasis in the endemic Umuowaibu and Ndiorji communities in southeastern Nigeria. Two skin snips (each from the shoulder and the waist) were taken for parasitological examination from each individual during daytime using a Walser corneoscleral punch. These individuals were also examined for gradations of skin manifestations and visual impairments using standard criteria. In all, 62 (49.6%) of those with chronic skin damage were positive for O. volvulus microfilaraemia, whereas 317 (35.3%) of those without chronic skin damage were positive for O. volvulus microfilaraemia. This difference was significant (?2-test; p < 0.001). The mf GMI of those with chronic skin damage (13 mf/snip) was significantly lower than the mf GMI of those without chronic skin damage (16 mf/snip) (t-test; p < 0.001). The mf prevalence of those with leopard skin (67.7%) was significantly higher than that in those without leopard skin (28.3%) (?2-test; p < 0.001). The mf GMI of those with leopard skin was significantly higher than that of those without leopard skin (t-test; p < 0.001). Most cases of leopard skin were seen in those aged 20 years and above. Of those with subcutaneous nodules, 63.7% were O. volvulus mf positive, with an overall mf GMI of 19 mf skin snip. Among those without subcutaneous nodules, 28.0% were O. volvulus mf positive with an mf GMI of 14 mf/skin snip. These differences were statistically significant (?2-test; p < 0.001; and t-test; p < 0.001). The prevalence of O. volvulus microfilaraemia was high among those who presented visual acuity problems with mf prevalence of 57.1% and mf GMI of 20 mf/skin snip. For those who did not present visual acuity problems, 35.5% were positive for O. volvulus microfilaraemia with mf GMI of 15 mf/skin snip. The difference in mf GMI was also statistically significant (t-test; p < 0.001). The difference in mf GMI was also statistically significant (t-test; p < 0.001). In conclusion, the O volvulus microfilaraemia was closely associated with most clinical manifestations especially among older age groups in the meso-endemic area. Keywords: Onchocerciasis, chronic inflammatory skin damage, leopard skin, subcutaneous nodules, visual acuity, Onchocerca volvulus, Nigeri

Comparative Seroprevalence and Risk Factors of Toxoplasmosis among Three Subgroups in Nigeria

The study was aimed at ascertaining the seroprevalence and some risk factors of toxoplasmosis among those attending the National Hospital, Abuja, Nigeria. Using the ImmunoComb  Toxo IgG Kit for the detection of IgG antibodies to Toxoplasma gondii in human serum/ plasma, 216 persons were examined for toxoplasmosis. This comprised of equal number (72 persons each) of persons from three subgroups, namely, gravid women, immuno-compromised persons consisting of patients with HIV and hepatitis, and the immuno-competent persons who are the controls. The overall seroprevalence of toxoplasmosis was 31.5%. Seroprevalence was significantly higher among pregnant women than among both the immuno-compromised and the immuno-competent persons (?2-test; p < 0.05 for both tests). Seroprevalence was comparable between the immuno-compromised and the immuno-competent (Controls) (?2-test; p > 0.05). Seroprevalence increased with age among gravid women, as well as among the immuno-compromised subgroups but not among the controls. Overall, seroprevalence among those living with cats/dogs (45.61%) was significantly higher than that of those living without cats/dogs (15.69%) (?2-test; p < 0.05); while the risk of infection with toxoplasmosis was four times higher than among those not living with cats (Odds Ratio 4.51). This was the same among the immune-compromised as well as the immune-competent where the risks of getting infected were five times higher among those cohabiting with cats (Odd Ratio 5.45 and Odds Ratio 5.36 respectively). Among the pregnant women, the risk of getting infected with toxoplasmosis was three times higher among those cohabiting with cats (Odds Ratio 3.00). Seroprevalence was independent of the tribal origin (?2-test; p < 0.05 for all the tests). Keywords: Toxoplasmosis, Toxoplasma gondii, serprevalence, pregnant women, immuno-compromised, immuno-competent, Nigeri

Bio-survey of Plankton as Indicators of Water Quality For Recreational Activities in Calabar River, Nigeria

With the increasing recognition of Calabar as a global tourist destination, the suitability of Calabar River for recreational activities by tourists was investigated. The aim was to use phytoplankton and zooplankton characteristics to assess the water quality of the Calabar River. Phytoplankton and zooplankton samples were collected from four stations along the river and carried in plastic containers at 4oC to the laboratory for taxonomic and diversity index analyses. Water samples were also collected from the sampling stations for physico-chemical analysis. In total, 331 phytoplankton individuals were identified from sixty-six species in sixty genera and six taxonomic groups. The most abundant taxon was Bacillariophyceae 212 (64.05%), followed by Cyanophyceae 42 (12.69%), Chlorophyceae 40 (12.08%); Dinophyceae 16 (4.83%); Chrysophyceae 12 (3.63%) and Xanthophyceae 9 (2.72%). Similarly, the diatoms were highest in species richness (54.55%) followed by Cyanophyceae (18.18%), Chlorophyceae (12.12%), Dinophyceae (6.06%), Chrysophyceae (4.55%), and Xanthophyceae (4.55%). Among the zooplankton, the Copepods were the most abundant (54.89%). Others were Protozoa (14.13%), Polychaeta larvae (7.07%), Cyclopoida (5.43%), Cladocera (5.43%), Arthropoda (4.89%), Ostracoda (3.26%), Rotifera (2.72%), Malacostraca (1.09%), and Foraminiferida (1.09%). The copepods were highest in species richness (13), representing 36.11% of the total. The other zooplankton taxonomic groups were Protozoa (16.67%), Cyclopoida (11.11%), Ostracoda (8.33%), Rotifera (8.33%), Cladocera (5.56%), Malacostraca (5.56%), Arthropoda (2.78%), Polychaeta larvae (2.78%), and Foraminiferida (2.78%). We did not observe any preponderance of harmful phytoplankton or zooplankton in the Calabar River during the study. The river showed no evidence of stress beyond her carrying capacity, and there was no evidence of any harmful environmental conditions that is detrimental to recreational activities in the Calabar River. We assess Calabar River as being biologically suitable for contact recreational activities, from the point of view of her plankton characteristics

Fever among Children in Calabar, Nigeria: Malaria, the Predominant Precursory Medical Condition

The study was aimed at elucidating the yearly total hospital admittances due to fever among children under 13 years and the associated underlying medical conditions between the years 2000 and 2011. Records of cases of fever among children under 13 years who presented with fever-associated medical condition and attended the General Hospital, Calabar between 2000 and 2011 were collated. The causes of the fever, age and sex of children were collected and collated. A total of 3663 children were admitted into the General Hospital Calabar with fever-associated medical condition between the year 2000 and 2011. Of these, males were 1520 (41.5%) while females were 2143 (58.5%). The sex-related difference was significant (x2-test; p < 0.05). The relative proportion of total annual fever cases ranged from 8.7% to 17.0% between 2000 and 2005, and 2.8% to 5.0% between 2006 and 2011. There are significantly higher number of cases between 2000 and 2005 than between 2006 and 2011 in all the categories of sex and age (t-test; p < 0.05 for all the tests). Malaria was associated with more than a third of the fever cases (39.3%) recorded. This was followed by Respiratory Tract Infection (RTI) which was associated with a fifth of all fever cases recorded (20.1%). In all, 25 medical conditions were found to be associated with fever among the children. The control of malaria and RTI would significantly reduce the burden of fever in Calabar. Keywords: Fever, malaria, Hospital attendance, Under 13 years childre

The Taxa Structure and Composition of Zooplankton Communities of Bonny Estuary: A Bio-indication of Anthropogenic Activities

This study was aimed at ascertaining the zooplankton taxa structure and composition as a way of assessing the environmental quality of the Bonny estuary. The plankton net of 55 μm meshsize was towed vertically, preserved in welllabeled 250 ml polyethylene bottles, and fixed with 10% formalin. In all, 2,928 zooplankton specimens were collected: Calanoid copepods were the most abundant constituting 55.3% of all collections, followed by Cyclopoida (10.2%), Harpacticoida (5.8%), Copepod larvae (17.0%); Annelida/Polychaeta larvae (1.9%); Chaetognatha (2.3%); Appendicularia (2.2%); Pisces larvae (2.6%); Tunicate larvae (0.6%); Cnidaria (0.1%); Ctenophora (0.1%); Echinodermata larvae (0.9%); Mollusca larvae (1.2%); Copepoda /Cladocera (0.03%); and Malacostraca (0.1%). A total of 119 species was collected, and Margalef’s diversity index ranged from 1.54 to 7.58. There was relatively higher abundance and diversity of zooplankton in the offshore sampling stations than in the near-shore sampling stations, probably due to impacts of natural, ecological, and anthropogenic factors. Mitigation measures to significantly check these anthropogenic activities among inhabitants of near-shore areas are recommended

Endemic mansonellosis in Emohua Local Government Area, Nigeria: human parasitaemia and Culicoides biting patterns

Background & objectives: The study was aimed at elucidating the prevalence and intensity of Mansonellaperstans microfilaraemia in the Emohua Local Government Area, Nigeria, and ascertaining the abundance,circadian, and the annual biting patterns of the Culicoides vector.Methods: Thick smear of 50 μl finger-prick blood stained with Giemsa was examined microscopically in across-sectional study. Vector landing collection on human bait was employed in a longitudinal study of thevector biting patterns, carried out between July 2005 and August 2006.Results: Of 1486 individuals examined, 11.2% of both males and females were positive for M. perstansmicrofilaraemia. Microfilaraemia appeared early in life. The overall geometric mean intensity among those withpositive microfilaraemia was 117 mf/ml (121 mf/ml for males and 113 mf/ml for females). The differences ingeometric mean intensity between different age groups were statistically significant (one-way analysis of variance;p <0.05), being highest in the oldest age group (266 mf/ml). A total of 1183 female Culicoides sp were caughtfrom September 2005 to August 2006. The abundance of Culicoides sp was seasonal. The circadian bitingactivity had a broad peak between 0700 and 1200 hrs. The monthly biting rates ranged from zero bite per personper month in January 2006 to 1151 bites per person per month in June 2006. The annual biting rate was 7382bites per person per year.Conclusion: Majority of those with positive microfilaraemia were poor socioeconomically, underscoring theneed for health education and application of effective control measures against Culicoides biting midges inEmohua