Utilization of Gliricidia Sepium Leaf Meal as Protein Source in Diets of Mozambique Tilapia, Oreochromis Mossambicus (Piscs: Cichlidae)

A series of experiments were conducted to evaluate the use of tropical fodder legume, Gliricidia sepium leaf as a potential source of protein in the diet of Mozambique tilapia, Oreochromis mossambicus. The effect of leaf age (plant leaf harvesting time) on crude protein (CP) and crude fiber (CF) contents of Gliricidia sepium were determined. G. sepium trees were pruned and leaf samples were taken monthly for five months. Results from chemical analyses of leaves revealed that in terms of its crude protein content, G. iv sepium leaves need to be harvested within 1-3 months after cutting. Leaves harvested from older trees tend to contain less protein. The chemical composition and apparent protein digestibility (APD) of Gliricidia sepium leaves by tilapia, O. mossambicus, were also investigated. G. sepium leaf meal was found to contain high (26.0%) crude protein but low in essential amino acids such as histidine, isoleucine, leucine, phenylalanine, valine and methionine. The apparent protein digestibility was found to be about 56%. In addition, G. sepium has the high crude fiber content. The optimum inclusion level of G. sepium leaf meal in tilapia (O. mossambicus) diet was also determined. Six diets containing 0%, 10%, 25%, 40%, 50% and 88% G. sepium leaf meal were prepared and fed at 4% per body weight per day for 27 g tilapia for 70 days. Growth performances data obtained revealed that the optimum inclusion level of G. sepium leaf meal is 40% of the total diet. Inclusion of G. sepium leaf meal above this level resulted in lower growth of O. mossambicus. The effect of different feeding rate on the performance of G. sepium leaf meal as O. mossambicus diet was also evaluated. Fish were fed diet containing 40% G. sepium leaf meal at 2%, 3%, 4% and 5% per fresh body weight per day. Data on growth and feed utilization performances showed v that O. mossambicus can be fed diet containing 40% G. sepium leaf meal at two percent of wet body weight per day. This feeding rate resulted in statistically comparative growth and feed utilization performance by the tilapia with 3%, 4% and 5% feeding rates. In addition to these, two processing methods of G. sepium leaf meal were compared. Three diets were prepared: 1) a control diet (using fishmeal as sole protein source), 2) oven-dried and 3) presoaked and dried G. sepium leaf meal. The diets were fed to O. mossambicus fingerlings for 70 days. Growth and feed utilization performances of O. mossambicus showed that the three diets resulted in similar performances. It was therefore concluded that G. sepium leaf meal can be used as oven-dried (unsoaked) meal. This might be due to the fact that the major anti-nutritional factors found in this legume are so low in the leaf part of the plant

Diversity and altitudinal distribution of phlebotomine sand flies (Diptera: Psychodidae) in visceral leishmaniasis endemic areas of northwest Ethiopia

Background: The Leishmaniases are caused by the protozoan parasites of the genus Leishmania and are transmitted to humans by the bite of infected female phlebotomine sand flies. Both visceral and cutaneous leishmaniases are widely distributed in different parts of Ethiopia. The aim of this study was to determine the diversity and altitudinal distribution of phlebotomine sand flies from Kafta Humera to Gondar town in northwest Ethiopia. Methods: Seven localities were selected with distinct altitudinal variations between 550 meters above sea level (ma.s.l) and 2,300ma.s.l. In each locality, sand flies were collected using standard CDC light traps and sticky traps during the active sand fly season from December 2012 to May 2013. Shannon-Weiner species diversity index and Jaccard’s coefficient were used to estimate species diversity and similarity between altitudes and localities, respectively. Results: A total of 89,044 sand flies (41,798 males and 47, 246 females) were collected from the seven localities/towns throughout the study period. Twenty-two species belonging to 11 species in the genus Phlebotomus and 11 species in the genus Sergentomyia were documented. Of these, Sergentomyia clydei (25.87%), S. schwetzi (25.21%), S. africana (24.65%), S. bedfordi (8.89%), Phlebotomus orientalis (6.43%), and S. antennata (4.8%) were the most prevalent species. The remaining 10 Phlebotomus species and six Sergentomyia were less frequent catches. In CDC light trap and sticky trap, higher species diversity and richness for both male and female sand flies was observed at low altitude ranging from 550 to 699ma.s.l in Adebay village in Kafta Humera district whereas low species richness and high evenness of both sexes was also observed in a altitude 1,950- 2,300ma.s.l. Conclusion: The results revealed that the presence of leishmaniasis vectors such as P. orientalis, P. longipes, P. papatasi, and P. duboscqi in different altitudes in northwest Ethiopia. P. orientalis a vector of L. donovani, was occurred between altitude 500- 1100ma.s.l, the area could be at high risk of VL. P. longipes a vector of L. aethiopica , was recorded in the highland area in Tikil-Dingay and Gondar town, implicating the possibility of CL transmission. Hence, further investigation into vector competence in relation to leishmaniasis (VL and CL) in the region is very vital

Onchocerciasis in Gilgel Ghibe River valley Southwest Ethiopia

Objective: To determine the prevalence of onchocerciasis and the entomological transmission indices such as the parous rate and annual transmission potential (ATP).Setting: Gilgel Ghibe village, Gilgel Ghibe River Valley Southwest Ethiopia between April 1994 and March 1995.Subjects: Two hundred twenty eight subjects of the total 400 population in Gilgel Ghibe village were subjected to parasitological and clinical examinations.Method: Two skin snips per person were taken and examined for microfilariae of Onchocerca volvulus. Fly collections were done from dawn to dusk from human baits seated in pairs at four representative sites at the river bank and away from the river bank. Flies were dissected for parity and infections with O. volvulus larvae.Results: Among the 228 people examined, the prevalence of the disease was low (17%), being higher in males (19%) than in females (14%). The geometric mean of microfilarial density was 11.1 (range, 1-132) mf per skin snip. Itching followed by pigmentary changes were the most common clinical signs and symptoms. The predominant anthropophilic blackfly species was Simulium (Edwardsellum) damnosum s.l. The annual parous rate and ATP were 74.7% and 1669.5, respectively, being higher at the river bank than at sites further away suggesting a greater risk of infection by the river side.Conclusion: The low prevalence of onchocerciasis in Gilgel Ghibe area vis-a-vis the high ATP level could be due to the possible presence of bovine onchocerciasis in the area. Further studies employing molecular techniques are thus required to identify O. volvulus from other filariae in flies

The effect of dams and seasons on malaria incidence and anopheles abundance in Ethiopia

Background: Reservoirs created by damming rivers are often believed to increase malaria incidence risk and/or stretch the period of malaria transmission. In this paper, we report the effects of a mega hydropower dam on P. falciparum malaria incidence in Ethiopia. Methods: A longitudinal cohort study was conducted over a period of 2 years to determine Plasmodium falciparum malaria incidence among children less than 10 years of age living near a mega hydropower dam in Ethiopia. A total of 2080 children from 16 villages located at different distances from a hydropower dam were followed up from 2008 to 2010 using active detection of cases based on weekly house to house visits. Of this cohort of children, 951 (48.09%) were females and 1059 (51.91%) were males, with a median age of 5 years. Malaria vectors were simultaneously surveyed in all the 16 study villages. Frailty models were used to explore associations between time-to-malaria and potential risk factors, whereas, mixed-effects Poisson regression models were used to assess the effect of different covariates on anopheline abundance. Results: Overall, 548 (26.86%) children experienced at least one clinical malaria episode during the follow up period with mean incidence rate of 14.26 cases/1000 child-months at risk (95% CI: 12.16 -16.36). P. falciparum malaria incidence showed no statistically significant association with distance from the dam reservoir (p = 0.32). However, P. falciparum incidence varied significantly between seasons (p < 0.01). The malaria vector, Anopheles arabiensis, was however more abundant in villages nearer to the dam reservoir. Conclusions: P. falciparum malaria incidence dynamics were more influenced by seasonal drivers than by the dam reservoir itself. The findings could have implications in timing optimal malaria control interventions and in developing an early warning system in Ethiopia

Further studies on the phlebotomine sandflies of the kala-azar endemic lowlands of Humera-Metema (north-west Ethiopia) with observations on their natural blood meal sources

<p>Abstract</p> <p>Background</p> <p>Visceral leishmaniasis (VL) has been known to exist in northwest Ethiopia (Humera-Metema lowlands) since the early 1970s associated with large scale agricultural development activities, often resulting in outbreaks. The latest outbreak of the disease that has started around 1995 in both regions, has led to the present preliminary entomological surveys (1996-2005) the results of which are reported here. Sandflies were collected using CDC light traps and <it>Phlebotomus </it>females were dissected for <it>Leishmania </it>detection and isolation; freshly fed <it>Phlebotomus </it>females collected were subsequently tested for their blood meal sources using ELISA. All <it>Phlebotomus </it>collections were identified to species.</p> <p>Results</p> <p>During the surveys (1996-2005), a total of 1963 sandflies of six <it>Phlebotomus </it>species (<it>P. orientalis</it>, <it>P. papatasi</it>, <it>P. bergeroti, P. duboscqi</it>, <it>P. rodhaini </it>and <it>P. alexandri</it>) were recorded from the study areas: the predominant species was <it>P. orientalis </it>in both localities. None of the total 618 <it>P. orientalis </it>females dissected (506 from Metema and 112 from Humera), nor the total 114 females of four other species dissected (<it>P. papatasi</it>, <it>P. duboscqi</it>, <it>P. bergeroti </it>and <it>P. rodhaini</it>) was infected with <it>Leishmania </it>promastigotes. ELISA-based blood meal analysis of 273 fresh fed <it>P. orientalis </it>females collected from Metema revealed a remarkably high bovine blood feeds (92%) with only 2.2% of human blood feeds.</p> <p>Conclusion</p> <p>Based on abundance and other circumstantial evidences (its proven role in Sudan), <it>P. orientalis </it>is the most likely vector of VL in northwest Ethiopia, pending further clarifications. The zoophagic feeding behaviour of <it>P. orientalis </it>detected in the present study could have epidemiological significance, but more investigations are required in this and other behavioural characteristics towards appropriate management of the vector.</p

A zoonotic focus of cutaneous leishmaniasis in Addis Ababa, Ethiopia

<p>Abstract</p> <p>Background</p> <p>Cutaneous leishmaniasis (CL) is endemic in the highlands of Ethiopia, and almost always caused by <it>Leishmania aethiopica</it>. Hitherto, Addis Ababa (the capital city of Ethiopia) was not considered endemic for CL, mainly due to absence of epidemiological and field ecological studies. This report summarizes the preliminary epidemiological investigation that proved the existence of active transmission in southeastern Addis Ababa.</p> <p>Results</p> <p>Active case finding surveys were conducted in 3 localities, Saris, Kality, and Akaki, which are found in and around Bulbula-Akaki river gorges. During the surveys conducted in January 2005 - May 2006, a total of 35 cases with 9 active and 26 healed skin lesions were identified. Eighteen of the cases (51.4%) were found in Saris; while 10 (28.6%) and 7 (20%) cases were from Kality and Akaki respectively.</p> <p>Ten colonies of rock hyraxes (<it>Heterohyrax brucei</it>) were identified in the vicinities of the 3 localities. Three of the 48 hyraxes (6.3%) trapped from the surroundings harbored natural infections of <it>Leishmania aethiopica</it>. Confirmation of the <it>Leishmania </it>species of the 3 isolates was achieved by PCR amplification and RFLP analysis of the ribosomal DNA internal transcribed spacer (ITS) sequences. Based on sandfly species composition and proximity of resting sites to human settlements, <it>Phlebotomus longipes </it>is circumstantially proven to be the vector of CL in south east Addis Ababa.</p> <p>Conclusion</p> <p>The study proves the existence of isolated zoonotic foci of CL in south eastern Addis Ababa, with <it>P. longipes </it>as the likely vector and <it>H. brucei </it>as the natural reservoir host.</p

OX40 (CD134) Controls Memory T Helper 2 Cells that Drive Lung Inflammation

Asthma is caused by memory Th2 cells that often arise early in life and persist after repeated encounters with allergen. Although much is known regarding how Th2 cells develop, there is little information about the molecules that regulate memory Th2 cells after they have formed. Here we show that the costimulatory molecule OX40 is expressed on memory CD4 cells. In already sensitized animals, blocking OX40–OX40L interactions at the time of inhalation of aerosolized antigen suppressed memory effector accumulation in lung draining lymph nodes and lung, and prevented eosinophilia, airway hyperreactivity, mucus secretion, and Th2 cyto-kine production. Demonstrating that OX40 signals directly regulate memory T cells, antigen-experienced OX40-deficient T cells were found to divide initially but could not survive and accumulate in large numbers after antigen rechallenge. Thus, OX40–OX40L interactions are pivotal to the efficiency of recall responses regulated by memory Th2 cells

Human-biting activities of Anopheles species in south-central Ethiopia.

BACKGROUND: Indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs) are the key malaria vector control interventions in Ethiopia. The success of these interventions rely on their efficacy to repel or kill indoor feeding and resting mosquitoes. This study was undertaken to monitor human-biting patterns of Anopheles species in south-central Ethiopia. METHODS: Human-biting patterns of anophelines were monitored for 40 nights in three houses using human landing catches (HLC) both indoors and outdoors between July and November 2014, in Edo Kontola village, south-central Ethiopia. This time coincides with the major malaria transmission season in Ethiopia, which is usually between September and November. Adult mosquitoes were collected from 19:00 to 06:00 h and identified to species. Comparisons of HLC data were done using incidence rate ratio (IRR) calculated by negative binomial regression. The nocturnal biting activities of each Anopheles species was expressed as mean number of mosquitoes landing per person per hour. To assess malaria infections in Anopheles mosquitoes the presence of Plasmodium falciparum and P. vivax circumsporozoite proteins (CSP) were determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Altogether 3,408 adult female anophelines were collected, 2,610 (76.6 %) outdoors and 798 (23.4 %) indoors. Anopheles zeimanni was the predominant species (66.5 %) followed by An. arabiensis (24.8 %), An. pharoensis (6.8 %) and An. funestus (s.l.) (1.8 %). The overall mean anopheline density was 3.3 times higher outdoors than indoors (65.3 vs 19.9/person/night, IRR: 3.3, 95 % CI: 1.1-5.1, P = 0.001). The mean density of An. zeimanni, An. pharoensis and An. funestus (s.l.) collected outdoors was significantly higher than indoors for each species (P < 0.05). However, the mean An. arabiensis density outdoors was similar to that indoors (11.8 vs 9.4/person/night, IRR: 1.3, 95 % CI: 0.8-1.9, P = 0.335). The mean hourly human-biting density of An. arabiensis was greater outdoors than indoors and peaked between 21:00 and 22:00 h. However, An. arabiensis parous population showed high indoor man biting activities during bedtimes (22:00 to 05:00 h) when the local people were indoor and potentially protected by IRS and LLINs. All mosquito samples tested for CSP antigen were found negative to malaria parasites. CONCLUSIONS: Results show much greater mosquito human-biting activities occurring outdoors than indoors and during early parts of the night, implying higher outdoor malaria transmission potential in the area. However, high bedtime (22:00 to 05:00 h) indoor biting activities of parous An. arabiensis suggest high potential intervention impact of IRS and LLINs on indoor malaria transmission