Ladslaus Laurent Mnyone

Dr. Ladslaus Laurent Mnyone


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 June 2020 in Journal of Vertebrate Biology
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Journal Article
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SCSimon Chidodo
Simon Chidodo
CKCharles Joseph Kilawe
Charles Joseph Kilawe
LMLadslaus Laurent Mnyone
Ladslaus Laurent Mnyone
BBBram Vanden Broecke
Bram Vanden Broecke
LMLoth S. Mulungu
Loth S. Mulungu
The Uluguru Mountains, which are part of the Eastern Arc Mountains, is a hotspot for diversity and an important area for the conservation of biodiversity in Tanzania, but faces increasing disturbance due to anthropogenic activities leading to a high rate of forest degradation and fragmentation. Changes in habitat structure have caused significant changes in the faunal assemblage of the region. However, information on these effects in the Uluguru Mountains is currently lacking. We conducted a survey of the small rodent assemblage on the Uluguru Mountains in three different habitats: forest, fallow, and cultivated land along two elevation gradients: 900-1,400 and 1,500-2,000 m a.s.l. Additionally, we recorded the habitat structure for each transect by looking at grass cover, tree density and shrub density. Generalised linear mixed models were used to examine the effects of habitat structure on both species richness as well as abundance. Our results revealed that, even while species richness remained similar over the whole study area, the species composition significantly changed depending on habitat structure. This finding arose particularly from changes in the numbers of Praomys delectorum and Mastomys natalensis, with the latter more abundant in cultivated and fallow land but not in forest, where P. delectorum is more abundant. This outcome may indicate that an increase in forest degradation and expansion of agriculture could have an impact on rodent assemblage and potentially on their population dynamics.

20 December 2022 in Parasites & Vectors
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GKGodfrey C. Katusi
Godfrey C. Katusi
MHMarie R. G. Hermy
Marie R. G. Hermy
SMSamwely M. Makayula
Samwely M. Makayula
RIRickard Ignell
Rickard Ignell
NGNicodem J. Govella
Nicodem J. Govella
LMLadslaus Laurent Mnyone
Ladslaus Laurent Mnyone
Background: Existing control tools have significantly reduced malaria over the past two decades. However, progress has been stalled due to increased resistance in primary vectors and the increasing role of secondary vectors. This study aimed to investigate the impact of seasonal change on primary and secondary vector abundance and host preference. Understanding the impact of seasonal dynamics of primary and secondary vectors on disease transmission will inform effective strategies for vector management and control. Methods: Vector abundance was measured through longitudinal collection of mosquitoes, conducted monthly during the wet and dry seasons, in Sagamaganga, a village in the Kilombero Valley, Tanzania. Mosquitoes were collected indoors using CDC light traps and backpack aspirators, and outdoors using resting buckets baited with cattle urine. In addition, a direct measure of host preference was taken monthly using human- and cattle-baited mosquito electrocuting traps. A host census was conducted to provide an indirect measure of host preference together with monthly blood meal source analysis. All collected mosquitoes were assayed for Plasmodium sporozoites. Results: A total of 2828 anophelines were collected, of which 78.5% and 21.4%, were primary and secondary vectors, respectively. The abundance of the primary vectors, Anopheles arabiensis and Anopheles funestus, and of the secondary vectors varied seasonally. Indirect measures of host preference indicated that all vectors varied blood meal choice seasonally, with the direct measure confirming this for An. arabiensis. All anopheline mosquitoes tested negative for sporozoites. Conclusions: At the study location, the abundance of both primary and secondary vectors changed seasonally. Indirect and direct measures of host preference demonstrated that An. arabiensis varied from being zoophilic to being more opportunistic during the wet and dry seasons. A similar trend was observed for the other vectors. Graphical

1 January 2020 in Research and Reports in Tropical Medicine
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JAJoseph N Aikambe
Joseph N Aikambe
LMLadslaus Laurent Mnyone
Ladslaus Laurent Mnyone
Background: Malaria is increasingly characterized by appreciable fine-scale variability in ecology and topography, and it is likely that we are missing some salient foci with unprecedented malaria transmission intensity in different parts of Tanzania. Therefore, efforts aimed at identifying area-specific malaria situation and intervening are needed to preserve the realized health gains and achieve elimination. Mkuyuni and Kiroka, adjacent wards within Morogoro Rural District, are purported to form one of such foci. Patients and Methods: A retrospective study was conducted to determine six-year (2014-2019) malaria prevalence rates based on outpatients and laboratory registers obtained from two health facilities, one per ward, carrying out diagnosis of malaria either through microscopy or malaria rapid diagnostic test (mRDT). These data were checked for completeness before carrying out statistical analysis. Results: Overall, 35,386 (46.19%) out of 76,604 patients were positive for malaria. The average proportion of malaria cases was significantly higher in Mkuyuni (51.23%; n=19,438) than Kiroka (41.21%; n = 15,938) (P <0.001). Females were more affected than males (P <0.001);, and irrespective of the sex, most malaria cases were recorded in children <5 years of age (P <0.001) except at Mkuyuni. Malaria was recorded virtually all year round; however, the highest proportion of cases was recorded in April and July (P <0.001). Conclusion: This study revealed high malaria endemicity in Mkuyuni and Kiroka, with prevalence rate as high as 60.98%, which is far higher than the overall national average prevalence of 9%. More studies are needed in these and other putatively high endemic foci in Tanzania in order to inform the future course of action in disease surveillance and control.

1 June 2020 in Journal of Vertebrate Biology
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AMAbeid M. Manyonyi
Abeid M. Manyonyi
SMSayuni B. Mariki
Sayuni B. Mariki
LMLadslaus Laurent Mnyone
Ladslaus Laurent Mnyone
Steven R BelmainSteven R Belmain
Steven R Belmain
LMLoth S. Mulungu
Loth S. Mulungu
A study on the effects of prescribed burning on rodent community ecology was conducted in Serengeti National Park, Tanzania. The study aimed at generating ecological knowledge about the changes in rodent communities when areas of the park are intentionally burned to regulate grasslands or reduce undergrowth that can lead to uncontrolled forest fires. A completely randomized design (CRD) factorial layout with two treatments (burned and unburned) and two replications was applied. A total of 148 animals comprising six species of rodent and one insectivore were captured over 2,940 trap nights. Among the trapped individuals, 41.9% were adults, 16.1% juveniles and 41.9% sub-adults. Males and females were at parity between treatments. Species abundance was estimated using the minimum number alive (MNA) method for different rodent species and was found to vary with treatment where Mastomys natalensis declined in burned plots whilst Arvicanthis niloticus increased. However, species diversity did not differ across treatments (F1, 10 = 0.15, p = 0.70). Differences in the reproductive condition of female M. natalensis (z = 4.408, df = 15, p < 0.001) and A. niloticus (z = 2.381, df = 15, p = 0.017) were observed between treatments showing that higher numbers of reproductively active females were observed in burned plots in March, whilst in unburned plots more were observed from November to February. Conservation strategies involving periodic habitat burning should, therefore, consider small mammal reproductive periods to ensure that species potentially at risk are not adversely affected and able to rapidly recover from the effects of burning in temporarily lowering food resources and longer term impacts of increased predation caused by reduced cover.

20 July 2020 in Research Square
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LMLadslaus Laurent Mnyone
Ladslaus Laurent Mnyone
BMBaraka Mwamundela
Baraka Mwamundela
Background: Understanding area-specific knowledge, attitudes, practices and demographic risk factors towards malaria is becoming critical for designing appropriate awareness and control strategies. Methods: A cohort of respondents from 243 randomly selected households across 3 villages in eastern Tanzania was assessed using a standard questionnaire and direct observation.Results: Fifty-three percent of respondents cited Anopheles mosquitoes that were responsible for transmitting malaria, and 85% of those explicitly cited female Anopheles mosquitoes. The rest (47%) knew that malaria is transmitted by a mosquito but could not name it. Commonly cited mosquito breeding sites were water bodies (75%) and rubbish (24%). Majority (61%) knew that the under-fives were most vulnerable to malaria. ITNs were mostly (64%) cited as a means of malaria control. Commonly cited malaria mosquito entry routes were windows (46%), eave opening (10%) and opening on the walls (4%). Majority (70%) confirmed malaria at the health facility. The rest (30%) relied on symptoms. Majority (96%) preferred modern antimalarials. Seventy-nine percent of the respondents owned at least one ITN. Cooking was done predominantly (77%) outdoors, finished cooking and went to bed after 20:00h. Most (58%) respondents still attended night-time outdoor communal gatherings without malaria protection. Conclusions: The current study indicate that majority of participants were aware that Anopheles mosquitoes were responsible for transmitting malaria, they bred in water, under-five children were most vulnerable to malaria, and ITNs constituted the most deployed control measure. Most respondents preferred confirming malaria at the health facility and treatment with modern antimalarials. Yet, the rate of self-diagnosis and self-medication, as well as inappropriate use of bednets requires great improvement. Demographic risk factors for early- and/or outdoor-transmission included night-time outdoor cooking and attending communal gatherings without malaria protection. The findings warrant a subsequent study to show a causal link between night-time outdoor activities, vector biting patterns and malaria prevalence.

15 January 2024 in Parasitologia
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Journal Article
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FMFilbert Ewald Mdee
Filbert Ewald Mdee
JLJeremiah Lyatuu
Jeremiah Lyatuu
EMEliakunda Michael Mafie
Eliakunda Michael Mafie
LMLadslaus Laurent Mnyone
Ladslaus Laurent Mnyone
The success of any tsetse control program depends on the knowledge of their behaviour. This study assessed the host choice and feeding behaviours of Glossina morsitans siblings whose parents were bloodfed on rabbits, guinea pigs, rodents, and squirrels. Each individual host was placed in a screen cage, which allowed flies to enter through openings on each side. The groups of flies (20 per replicate), which were colour-marked differently based on their parents’ blood meal hosts, were released from the centre of large semi-field cage. The released flies were aspirated after 24 h and then sorted based on their location, feeding status, and parents’ blood meal. A total of 213 flies (72.95% of those recovered) were attracted to the hosts. The numbers of flies attracted to different hosts varied significantly (χ24 = 33.685, p = 0.0001): rodents (n = 80, p = 0.006), rabbits (n = 59, p = 0.331), guinea pigs (n = 49, p = 0.057), and squirrels (n = 25, p = 0.005). The numbers of flies attracted to their parent’s blood meal source varied significantly (χ212 = 56.476, p < 0.001): rabbits (n = 35, 59.32%, p < 0.001), rodents (n = 25, 31.25%, p = 0.043), and guinea pigs (n = 19, 38.78%, p = 0.45). But only 39 flies (18.31% of the total attracted) bloodfed on the hosts, including guinea pigs (n = 10, 25.64%), rodents (n = 23, 58.97%), rabbits (n = 6, 15.38%), and squirrels (n = 0, 0.0%). There was significant variation in the number of flies that fed successively across hosts (χ24 = 49.478, p < 0.001). The findings from this study confirm the presence of differential attractiveness of the hosts to flies and the so-called “Hopkins host selection principle” or “pre-imaginal conditioning”. Therefore, the study attracts the need for detailed investigation on the influence of blood meal sources on tsetse fly siblings’ behaviours across filial generations using small mammals or other large mammal species.