Spatial and temporal distribution of Anopheles mosquito's larvae and its determinants in two urban sites in Tanzania with different malaria transmission levels.

BACKGROUND: In order to be able to design and implement control measures directed to the mosquito larva stages an understanding of the spatial and temporal distribution and its determinants in different malaria transmission settings is important. This study therefore, intended to determine the spatial and temporal distribution of Anopheles mosquito's larvae and its determinants in two urban sites with different transmission levels, in Tanzania. METHODOLOGY: This study was conducted in Dodoma and Morogoro regions in Tanzania. The study was an ecological study of repeated cross-sectional type. Searching for water bodies in the selected wards was done by going around all streets. Potential breeding sites were given unique identification numbers and larval sampling was done using the standard dipping method with a 350 ml mosquito scoop and a calibrated pipette. Visual identification of presence of larvae and its abundance in each sampling were used to describe the larvae density. A sample of Anopheles mosquitoes which emerged from collected larvae, were processed for species identification using PCR. Descriptive statistics were arrived at by calculating different proportions for the variables. The overall impact of the variables on the density of Anopheles larvae was tested using multiple logistic regression. Variables with p-value less than 0.05 were regarded as significant. RESULTS: A total of 724 water bodies out of which, 576 (79.6%) potential breeding sites were analyzed. It was found that, most (96.2%) of the potential breeding sites were manmade and most (59.5%) were less than 5 m in diameter and 87.2% were within 100 m from human settlement. Out of all the potential breeding sites, 69.8% and 30.2% were in Morogoro and Dodoma respectively, out of which 72.2% and 68.4% respectively, were found during rainy season. Habitats with clean water, at a distance of 10-100 m from the house, in natural, shaded and partial sunlight habitats had higher odds of having high density of mosquito larvae than their counterparts (p < .05). The PCR analysis showed that 72.5% were An. arabiensis, 4.5% An. gambiaes.s, 0.5% An.coustaniand 20% An. quadrianulatuswhile 2.5% of the samples could not be identified because DNA was not amplified. CONCLUSION AND RECOMMENDATION: Type of water, distance from the breeding site to human settlement, light intensity and habitat origin were significant predictors of variation on the spatial and temporal distribution of Anopheles mosquito breeding sites. With increased global emphasis on control measures that targets mosquito immature stages; we recommend that larval control measures should be developed while considering the findings from this study.

Hirudiniasis in Cattle in Mpwapwa District, Dodoma Region of Tanzania.

Hirudiniasis is a condition caused by infestation by leeches. Despite the annoyance, clinical signs, and associated lesions caused by leeches in both humans and animals, the extent of the problem in Tanzania is not well elucidated. Individual animals and people become infested when they drink, bath, or walk through contaminated water sources. Leech infestations are more common in rural areas where water is scarce especially during the dry season. In this report, clinical cases of hirudiniasis in twenty-seven (27) cattle in Mpwapwa, Tanzania, are presented. The report further reviews the morphological features of leeches and creates awareness among the affected cattle farmers and the general public. A total of two hundred (200) live cattle were examined; out of these, 27 cattle had live leeches. There were, on average, 3-8 leeches per animal. Affected cattle had wounds on the gums, buccal mucosa, root of the tongue, and under the tongue with copious amounts of blood-stained frothy discharge. Further, the affected animals had respiratory distress and were rolling their tongues. The leeches were manually removed from all the affected cattle, with uneventful recovery. Laboratory examination revealed segmented, dorsal-ventral flattened, cylindrical parasites which had posterior and anterior suckers. The leech infestation was linked to drinking water from a pond which was suspected to be contaminated with "undescribed organisms" as indicated by the farmers. A follow-up was made and revealed no new cases and complete recovery of the affected animals. Hirudiniasis is one of the neglected diseases in humans and livestock and, therefore, requires integrated efforts especially in areas where water is scarce during the dry season. It is anticipated that this case report will stimulate interest and more studies in the subject matter to understand the extent of the problem and document the species and distribution of leeches in Tanzania.

A cross-sectional study on the use and misuse of trypanocides in selected pastoral and agropastoral areas of eastern and northeastern Tanzania.

BACKGROUND: Tsetse-borne African animal trypanosomosis (AAT) greatly influences livestock distribution and significantly slows livestock productivity in sub-Saharan Africa. While a number of control methods targeting the vector tsetse are in field application, treatment with the few available trypanocides continues to be the most widely applied control method. Unfortunately, improper and frequent use of these few available drugs, accelerated by poor veterinary service delivery, promotes trypanosome drug resistance, the magnitude of which has not been delineated. In the present study, current practices on trypanocide application for the control of bovine trypanosomosis in the field in Tanzania were studied with a view to providing policy advice on the safe and sustainable use of trypanocides. METHODS: A cross-sectional study was conducted using a semi-structured questionnaire administered to a total of 200 randomly selected livestock keepers in selected pastoral and agropastoral areas within three districts in eastern and north eastern Tanzania. RESULTS: In total, 50% of respondents in all three study districts had primary level education; over 40% had informal education and only 5% with university education (all from one district, Pangani). Age-wise, most respondents were aged 30-59 years with exception of Korogwe where 35% were aged 20-29 years. Over 95% of respondents had knowledge on tsetse as a vector of trypanosomosis and correctly identified tsetse in provided pictures. Furthermore, 98.7% of the respondents applied pyrethroids for vector control. Regarding parasite control practices, this study revealed a high degree of variation in trypanocides usage and the intervals of their application. Whereas only 20% of respondents use chemoprophylaxis for trypanosomosis control, the majority (69-95%) wrongly use diminazene aceturate thinking it is prophylactic, while only 5-30% used the prophylactic drug isometamidium chloride. Most of the respondents (95% in Korogwe, 60% in Pangani and 93.1% in Mvomero) administered the drugs on their own. Improper trypanocides administration was high as respondents in Korogwe (75%) and Mvomero (72%) administered the drugs intravenously with a view to achieving faster drug effect contrary to manufacturers' recommendations, while 40% of respondents from Pangani used both intravenous and intramuscular routes. Additionally, respondents did not observe the recommended withdrawal periods for the drugs. CONCLUSIONS: This study revealed a high level of trypanocides misuse which poses a high risk of trypanosome drug resistance development as well as risks to human health from drug residues in consumed animal products. This calls for improvements in veterinary service delivery in pastoral and agropastoral areas of Tanzania to counteract the misuse of chemotherapeutics.

In vivo effect of Commiphora swynnertonii ethanolic extracts on Trypanosoma congolense and selected immunological components in mice.

BACKGROUND: The search for alternative trypanocidal compounds which can be available at affordable price is of paramount importance for control of trypanosomosis in human and animals. The current study evaluates the in vivo activity of ethanolic stem bark extracts on Trypanosoma congolense and selected immunological components in an inbred Swiss albino mouse model. METHODS: Groups of mice infected with T. congolense were treated with the stem bark extracts at a rate of 1000 mg/kg, 1500 mg/kg, and 2000 mg/kg, twice a day in one set and thrice a day in another setting for three days consecutively. Negative (infected and untreated) and positive (infected treated with diminazene diaceturate at 3.5 mg/kg) control groups were used. Levels of parasitaemia were monitored daily for the first 10 days and thereafter 2-3 times per week to the end of experiment. In the other setting, uninfected mice, randomized in groups were treated with the extract but categorized as: thorough mixed extract (TME) and supernatant extract (SE) each at 500 mg/kg and 1500 mg/kg, in 8 hourly intervals respectively for three days consecutively. Control group was administered with phosphate buffered saline with glucose at 0.1 ml/10 g in a similar manner as for the extract. Whole blood and spleen were taken 24 h after the last treatment for hematological and histopathological analysis. RESULTS: The groups that received the extracts at 8 hourly intervals drastically reduced the parasitaemia. The higher dose of SE significantly reduced the percentage of lymphocytes (P < 0.05). Both high and low dose of TME significantly reduced lymphocytes percent (P < 0.05) while percent of neutrophils and monocytes increased significantly (P < 0.05). Histopathological changes of the spleen in the mice treated with higher concentrations of the extract of C. swynnertonii were suggestive of lymphocytes toxicity. CONCLUSION: The current study has provided evidence that, in vivo trypanocidal activity of ethanolic bark extracts of C. swynnertonii is probably affected by its negative effect on humoral mediated immune response. Further studies are recommended to determine its potential as an alternative source of lead compounds for trypanocidal drug discovery.

Advancements in bait technology to control Glossina swynnertoni Austen, the species of limited distribution in Kenya and Tanzania border: A review.

Glossina swynnertoni is a savannah tsetse that is largely confined to the Serengeti-Mara [a very small part of East Africa covering northern Tanzania (Arusha and Manyara regions and parts of Shinyanga and Mara regions) extending Maasai Mara ecosystem in southwestern Kenya]. Nevertheless, it is of great concern to human and animal health and is one of the top target tsetse species for eradication. To achieve this eradication objective, it is important to know about its behaviour so that the appropriate tools/measures especially the right traps can be applied against it. In this paper G. swynnertoni is reviewed in terms of its behaviour, and development of traps for its survey and control. Glossina swynnertoni control is of paramount importance in Tanzania tourism industry and country's income. Since, G. swynnertoni is also distributed in national parks, control is vital as it might reduce tourists excursion/movement, by transmitting the African trypanosomiasis among travelers. Different literature search engines such as Google Scholar and PubMed were deployed for literature search. It was found that the behaviour of G. swynnertoni is relatively similar but unique from other tsetse flies. Its feeding cycle is 2½-3 days as opposed to 3-4 days observed in other tsetse species. The flight activity pattern varied between sex, with male having their peak at 1100-1200 hrs and females 1400-1600 hrs. The activity in both sexes decline rapidly towards the dusk (1700-1800 hrs). It was further that host odours, relatively smaller and vertically oriented devices, as well as host movement are the main attractive factors to this tsetse species, which can be exploited to design efficient artificial devices for control of G. swynnertoni . Therefore, due to its restricted distribution and threat it poses on tourism industry, deliberate efforts need to be made against G. swynnertoni as a next candidate to be eradicated using artificial bait technology.

Potential use of mobile phones in improving animal health service delivery in underserved rural areas: experience from Kilosa and Gairo districts in Tanzania.

BACKGROUND: Sub-optimal performance of the animal health delivery system in rural areas is common in developing countries including Tanzania. However, penetration of mobile phones and availability of good road network and public transport systems offer opportunities for improving the access of rural communities to diagnostic and advisory services from facilities and expertise located in urban areas. A questionnaire survey on possession and use of mobile phones by pastoral and agro-pastoral communities in Kilosa and Gairo districts was carried out between November and December 2015. A total number of 138 livestock keepers from three villages of Chakwale (54), Mvumi (41) and Parakuyo (43) participated in the study. An e-based system was designed and tested to link rural communities with urban diagnostic facilities. RESULTS: It was observed that the average number of phones possessed by individuals interviewed and household families was 1.1 ± 0.26 (1-2) and 3.5 ± 2.23 (1-10), respectively. It was further observed that out of 138 livestock keepers interviewed, 133 (96.4 %) had feature phones while 10 (7.2 %) of them possessed smartphones. Mobile phone is currently used to support livestock production by communicating on animal health in Parakuyo (18, 41.9 %), Mvumi (18, 43.9 %) and Chakwale (14, 25.9 %). Other contributions of mobile phones in livestock and crop agriculture observed in the study area include: exchange of livestock price information, crop price information, communicating on plant health/diseases, livestock extension and advisory services as well as crop farming extension and advisory services. We also designed and tested an e-based SUAVetDiag® system to support timely diagnosis of infectious disease conditions and prompt advice on case management in veterinary underserved areas. CONCLUSIONS: Availability of mobile phones in rural areas, in combination with supporting infrastructure and facilities in urban areas, has potential to stimulate local development and improving delivery of animal health and extension services. It is recommended that more development and refinement of the system should be conducted to ensure that this potential is tapped to revolutionalise delivery of animal health services in rural areas.

Trypanocidal activity of ethanolic extracts of Commiphora swynnertonii Burtt on Trypanosoma congolense.

BACKGROUND: African trypanosomosis is the disease caused by extracellular protozoan parasites of the genus Trypanosoma transmitted by tsetse flies. The current study has evaluated the trypanocidal activity of Commiphora swynnertonii extracts on Trypanosoma congolense. METHODS: The effect of ethanolic stem bark and resinous extracts on motility of T. congolense was evaluated by in vitro study at concentrations of 2 mg/ml and 4 mg/ml. Then, trypanocidal activity was evaluated by drug incubation infectivity test using mice at concentrations of 0.4 mg/ml and 2 mg/ml. In both studies negative (without drug) and positive (diminazene diaceturate) controls were used. RESULTS: The in vitro study showed that, ethanolic stem bark extract of C. swynnertonii at concentration of 4 mg/ml caused complete cessation of motility for T. congolense in 30 min. However, resinous ethanolic extract had delayed effect on cessation of motility of T. congolense observed at 90 and 100 min post-incubation at concentrations of 4 mg/ml and 2 mg/ml respectively. The drug incubation infectivity test study depicted that ethanolic stem bark extract at concentration of 2 mg/ml significantly (p = 0.000) reduced the infectivity of T. congolense in mice. However, it did not vary significantly (P =0.897) with group treated with diminazene diaceturate incubated mixture. CONCLUSION: The current study has provided evidence that, ethanolic stem bark extract of C. swynnertonii possess trypanocidal activity against T. congolense. Based on these findings, further studies are recommended to determine its potential as a lead to trypanocidal drug discovery.

Knowledge and awareness of malaria and mosquito biting behaviour in selected sites within Morogoro and Dodoma regions Tanzania.

BACKGROUND: In Tanzania there has been a downward trend in malaria prevalence partly due to use of insecticide-treated bed nets for protection against Anopheles mosquitoes. However, residual malaria transmission attributed to early biting behaviour of malaria vectors is being reported. Knowledge of mosquito feeding behaviour is key to improvements in control approaches. The present study aimed to assess knowledge and awareness on malaria and malaria vectors in-Morogoro and Dodoma regions of Tanzania. METHODS: A cross sectional study was undertaken in selected sites in Morogoro and Dodoma Tanzania. A structured questionnaire was administered to 218 randomly selected households from each of which the head or second in/charge and the most senior primary school child were interviewed. RESULTS: A total of 400 participants of whom 56 % were females, were recruited into the study. Their ages ranged between nine and 58 years. Among the participants, 70.7 % had primary school education and the rest attained secondary school (16.8 %), university/college (4.0 %) and not attended school at all (8.5 %). Fifteen per cent of the participants were employed, while 45.5 % were self-employed and 39.5 % were studying. Overall, 58.5 % of respondents were knowledgeable of malaria and its vector. However, 78.8 % were not aware that early mosquito bites can transmit malaria and 86.5 % said that only midnight-biting mosquito bite was responsible for malaria transmission. The majority (66 %) of respondents visited a health facility on observing malaria symptoms while 15.8 % took anti-malaria drugs without medical consultation. CONCLUSION: This study has shown that Anopheles is well known as the night-biting vector of malaria. The majority of participants were not aware of changed biting behaviour of malaria-transmitting mosquitoes and that early outdoor mosquito bite is a risk of malaria transmission. School children have shown a better understanding of malaria and its vector. Therefore, more awareness of Anopheles feeding behaviour is needed.