5 research outputs found
Multiple Trypanosoma infections are common amongst Glossina species in the new farming areas of Rufiji district, Tanzania
<p>Abstract</p> <p>Background</p> <p>Tsetse flies and trypanosomiasis are among several factors that constrain livestock development in Tanzania. Over the years Rufiji District was excluded from livestock production owing to tsetse fly infestation, however, a few years ago there was an influx of livestock following evictions aimed at conserving the Usangu wetlands.</p> <p>Methods</p> <p>A study was conducted to determine the efficiency of available traps for catching tsetse flies, <it>Glossina </it>species infesting the area, their infection rates and <it>Trypanosoma </it>species circulating in the area. Trapping was conducted during the semi dry season for a total of 30 days (ten days each month) during the onset of the dry season of May - July 2009. Harvested flies after every 24 hours were dissected and examined under a light microscope for trypanosome infections and whole fly DNA was extracted from 82 flies and analyzed for trypanosomes by polymerase chain reaction (PCR) using different sets of primers.</p> <p>Results</p> <p>The proportions of total tsetse catches per trap were in the following decreasing order S3 (33%), H-Trap (27%), Pyramidal (19%), sticky panel (11%) and biconical trap (10%). Of the 1200 trapped flies, 75.6% were identified as <it>Glossina pallidipes</it>, 11.7% <it>as G. brevipalpis</it>, 9.6% as <it>G. austeni </it>and 3.0% <it>G. morsitans morsitans</it>. Dissections revealed the overall infection rate of 6.6% (13/197). Whole DNA was extracted from 82 tsetse flies and the prevalence of trypanosomes circulating in the area in descending order was 92.7% (76/82) for <it>T. simiae</it>; 70.7% (58/82) for <it>T. brucei </it>types; 48.8% (40/82) for the <it>T. vivax </it>types and 32.9% (27/82) for the <it>T. congolense </it>types as determined by PCR. All trypanosome types were found in all tsetse species analysed except for the <it>T. congolense </it>types, which were absent in <it>G. m. morsitans</it>. None of the <it>T. brucei </it>positive samples contained human infective trypanosomes by SRA - PCR test</p> <p>Conclusion</p> <p>All tsetse species found in Rufiji are biologically important in the transmission of animal trypanosomiasis and the absence of <it>T. congolense </it>in <it>G. m. morsitans </it>could be a matter of chance only. Therefore, plans for control should consider all tsetse species.</p
Modeling Transmission Dynamics of Northern Corn Leaf Blight Disease with Seasonal Weather Variations
This research article published by the Journal of Mathematics and Informatics, Vol. 15, 31 January 2019Northern Corn Leaf Blight (NCLB) disease is a fungal foliar disease caused by
Exserohilum turcicum. Moderate temperature and high relative humidity are climatical
conditions which favor the development of NCLB disease. A deterministic model for
transmission dynamics of NCLB disease with seasonal weather variations is developed
and vigorously analyzed. The basic reproduction number in the absence and presence
of the impact of temperature and relative humidity is computed and the sensitivity
analysis performed to determine the parametersā relationship with basic reproduction
number
. The analysis shows that transmission rate from pathogen to susceptible maize
plants, the pathogenās shedding rate from infected maize plants to the environment and
maize plants disease induced death rate are more sensitive to NCLB disease dynamics
and they play an important role in its transmission. On the other hands when there are
high or low temperature and low humidity, sensitive negative parameters increases as the
results NCLB disease development decreases. However, increasing parameters such as
natural death rate of the pathogen, the natural death rate for maize plants and maize
plantsā disease induced death rate which have negative indices will reduce new
infections. Moderate temperature and high relative humidity influence NCLB disease
development