Prevalence of Trypanosoma congolense and Trypanosoma vivax in Lira District, Uganda
| dc.contributor.author | Aziz Katabazi, Adamu Almustapha Aliero , Sarah Gift Witto, Martin Odoki , and Simon Peter Musinguzi | |
| dc.date.accessioned | 2024-07-18T14:24:58Z | |
| dc.date.available | 2024-07-18T14:24:58Z | |
| dc.date.issued | 2021-06-15 | |
| dc.description.abstract | Animal African trypanosomiasis (AAT) is one of the most significant vector-borne diseases of domestic animals in the Tsetse belt of Africa including East Africa. AAT is caused by Trypanosoma species which are transmitted cyclically by the tsetse fly belonging to the Glossina spp. Animal African trypanosomiasis (AAT) affects a wide range of hosts, namely, goats, sheep, donkeys, and cattle. The disease is characterized by the presence of parasites in the blood and alternating fever. Anaemia usually develops in infected animals, accompanied by weight loss, body loss, miscarriage, abortion, decreased productivity, and sometimes mortality [3]. Animal African trypanosomiasis causes more than 3 million animals to die each year with 50 million animals at risk of infection [4]. Therefore, AAT is the main hindrance to food security, as it makes vast areas of semiarid savannah land in Africa unsuitable for breeding domestic animals that are a source of dairy and meat production. Also, AAT remains a setback in most livestock-dependent economies in Sub-Saharan Africa, causing economic losses of agricultural productivity of about 20% [6], and because most livestock rearing is commonly practiced by rural communities, AAT impedes rural development [7]. In livestock, AAT is caused by Trypanosoma congolense, Trypanosoma vivax, Trypanosoma evansi, Trypanosoma simiae, and Trypanosoma brucei brucei [8]. Trypanosoma species infection in cattle is primarily spread through bites of infected tsetse flies found in over 37 African countries in Sub-Saharan Africa including Uganda [9]. Other biting flies such as Stomoxys have also been implicated in the spread of AAT although they lack epidemiological significance [10]. Several host factors, including the physiological status of the host and nutritional and environmental factors, have an important effect on pathogenicity and determine the severity of the disease [11]. Illness in animals affected with T. congolense, T. vivax, or T. b. brucei is characterized by fluctuating parasitaemia with periods of paroxysms and intermission. This leads to anaemia; the roughness of the hair coat, abortion, reduced milk yield, intermittent pyrexia, depression, and gradual loss of condition lead to extreme emaciation and death of the animal. Diagnosis is an important factor in the controlling of infection. Several diagnostic techniques for trypanosomiasis exist; however, only a few tests have been objectively analyzed and standardized. Trypanosomiasis has traditionally been diagnosed using microscopy to directly observe the Trypanosoma parasites in blood either through a wet film system for detecting mobile trypanosomes or as thick and thin dried smears. Recently, with the explosion of new techniques, because of the rapid developments in molecular biology, new approaches and technologies can be used for diagnosis. The use of molecular methods such as polymerase chain reaction (PCR) has helped to diagnose and classify Trypanosoma species. There are several methods for detecting trypanosomiasis in animals, including parasitological, immunological, and molecular methods. This study used traditional microscopy and molecular techniques to quantify the prevalence and identify the circulating species. Materials and Methods Study Area. This study took place in Lira District, Uganda (Figure 1), which is located in the following coordinates: 2°14′50.0″N 32°54′00.0″E (latitude: 02.2472; longitude: 32.9000) in Northern Uganda [17]. Lira District is the main economic hub in northern Uganda, and livestock keeping is one of the main economic activities. Furthermore, Lira District is one of the districts that benefitted from the restocking program funded by the African Development Bank (ADB). In 2008, the national livestock census reported the cattle population to be 15,933. This put Lira District among the cattle-rearing districts which rendered it an AAT hotspot. The cattle were sampled from the Acungkena, Barropok, and Acanakwo A sub counties. 2.2. Sample Size Determination. This study used a survey formula previously reported by Kish [18]: n = z2pð1 −pÞ/d2, where z is the Z score for 95%confidenceinterval = 1:96, p is the prevalence, and d is the acceptable error (5%). We used the prevalence of bovine African trypanosomes 15.3% in Tororo District, southeastern Uganda [1]. 2.3. Study Design. This was a cross-sectional study aimed at establishing the prevalence of Animal African trypanosomes in Lira District using two selected diagnostic methods. A simple random sampling technique was used to identify the study sites. Two hundred and fifty-four (254) animals were selected and assigned unique numbers for identification according to the village and farm that they came from. This study was carried out from March 2020 to April 2020. 2.4. Sample Collection. From each selected animal, the blood was collected from the jugular vein into vacutainer tubes containing EDTA stored at 4°C in a cooler box, and transported to the district laboratory for microscopy analysis and sample processing for molecular analysis. For molecular analysis, the blood from the vacutainer tubes was applied onto Whatman FTA cards left to dry, and then stored in sealed plastic bags at room temperature. To have a higher chance of detecting parasites, blood sample collection was done in the morning. 2.5. Microscopy. For microscopy, 50μl of whole blood was used to make thin and thick blood films. The blood films were allowed to air dry and then fixed in concentrated methyl alcohol for about 1-2 minutes followed by staining with 10% Giemsa for 25-35 minutes. The blood films were then washed with distilled water to remove the excess stain, and the slides were left to air dry before viewing under an oil immersion lens. | |
| dc.description.sponsorship | King Ceasor University | |
| dc.identifier.citation | https://doi.org/10.1155/2021/7284042 | |
| dc.identifier.uri | https://doi.org/10.1155/2021/7284042 | |
| dc.identifier.uri | https://ir.kcu.ac.ug/handle/20.500.14433/34 | |
| dc.language.iso | en | |
| dc.publisher | Hindawi | |
| dc.title | Prevalence of Trypanosoma congolense and Trypanosoma vivax in Lira District, Uganda | |
| dc.type | Article |