Blood tumour necrosis factor-α and the pathogenesis of anaemia in Trypanosoma brucei infected rabbits

Trypanosomosis is a protozoan infection of domestic and wild animals characterized by anaemia, however, the pathogenesis of trypanosomosis-induced anaemia is not fully understood. This study evaluated the possible roles of Tumour Necrosis Factor-alpha (TNF-α) in the pathogenesis of anaemia induced by Trypanosoma brucei in rabbits. Twelve adult rabbits of both sexes with mean weight of 2.1 ± 0.1kg were randomly assigned into two groups of six rabbits each. Group A rabbits were intraperitoneally (i.p) infected with blood containing 2 x 106/ml of T. brucei, while group B (control) rabbits were injected with one ml of normal saline i.p. Blood was collected from the ear vein before infection and weekly thereafter for six weeks post-infection (p.i), in order to determine the packed cell volume (PCV), haemoglobin (Hb) concentration, red blood cell (RBC) count, reticulocyte count (RC) and serum concentrations of TNF-α. The PCV, RBC count and Hb concentration were significantly (p<0.05) lower in group A than group B rabbits throughout the duration of the study. Serum concentration of TNF-α was significantly (p<0.05) higher in group A (227.5 ± 8.1 ng/ml) than group B (51.3 ± 8.2 ng/ml) at week four post-infection. The serum concentration of TNF-α negatively correlated with PCV (r=-0.513) and Hb (r=-0.769) in group A. The study concluded that anaemia observed during experimental infection in rabbits with trypanosomosis was associated with increased levels of TNF-α.Keywords: Anaemia, Rabbits, Pathogenesis, Trypanosomosis, Tumour Necrosis Factor-

<i>Trypanosoma brucei rhodesiense</i> transmitted by a single tsetse fly bite in vervet monkeys as a model of human African trypanosomiasis

Sleeping sickness is caused by a species of trypanosome blood parasite that is transmitted by tsetse flies. To understand better how infection with this parasite leads to disease, we provide here the most detailed description yet of the course of infection and disease onset in vervet monkeys. One infected tsetse fly was allowed to feed on each host individual, and in all cases infections were successful. The characteristics of infection and disease were similar in all hosts, but the rate of progression varied considerably. Parasites were first detected in the blood 4-10 days after infection, showing that migration of parasites from the site of fly bite was very rapid. Anaemia was a key feature of disease, with a reduction in the numbers and average size of red blood cells and associated decline in numbers of platelets and white blood cells. One to six weeks after infection, parasites were observed in the cerebrospinal fluid (CSF), indicating that they had moved from the blood into the brain; this was associated with a white cell infiltration. This study shows that fly-transmitted infection in vervets accurately mimics human disease and provides a robust model to understand better how sleeping sickness develops

A longitudinal survey of African animal trypanosomiasis in domestic cattle on the Jos Plateau, Nigeria:prevalence, distribution and risk factors

BACKGROUND: Trypanosomiasis is a widespread disease of livestock in Nigeria and a major constraint to the rural economy. The Jos Plateau, Nigeria was free from tsetse flies and the trypanosomes they transmit due to its high altitude and the absence of animal trypanosomiasis attracted large numbers of cattle-keeping pastoralists to inhabit the plateau. The Jos Plateau now plays a significant role in the national cattle industry, accommodating approximately 7% of the national herd and supporting 300,000 pastoralists and over one million cattle. However, during the past two decades tsetse flies have invaded the Jos Plateau and animal trypanosomiasis has become a significant problem for livestock keepers. METHODS: In 2008 a longitudinal two-stage cluster survey on the Jos Plateau. Cattle were sampled in the dry, early wet and late wet seasons. Parasite identification was undertaken using species-specific polymerase chain reactions to determine the prevalence and distribution bovine trypanosomiasis. Logistic regression was performed to determine risk factors for disease. RESULTS: The prevalence of bovine trypanosomiasis (Trypanosoma brucei brucei, Trypanosoma congolense savannah, Trypanosoma vivax) across the Jos Plateau was found to be high at 46.8% (39.0 – 54.5%) and significant, seasonal variation was observed between the dry season and the end of the wet season. T. b. brucei was observed at a prevalence of 3.2% (1% – 5.5%); T. congolense at 27.7% (21.8% - 33.6%) and T. vivax at 26.7% (18.2% - 35.3%). High individual variation was observed in trypanosomiasis prevalence between individual villages on the Plateau, ranging from 8.8% to 95.6%. Altitude was found to be a significant risk factor for trypanosomiasis whilst migration also influenced risk for animal trypanosomiasis. CONCLUSIONS: Trypanosomiasis is now endemic on the Jos Plateau showing high prevalence in cattle and is influenced by seasonality, altitude and migration practices. Attempts to successfully control animal trypanosomiasis on the Plateau will need to take into account the large variability in trypanosomiasis infection rates between villages, the influence of land use, and husbandry and management practices of the pastoralists, all of which affect the epidemiology of the disease

Prevalence And Distribution Of Ruminant Trypanosomosis In Bokkos Local Government Area Of Plateau State, Nigeria

The seasonal prevalence of typanosomosis was investigated in Bokkos LGA of Plateau State, Nigeria. A total of 740 animals (684 cattle and 56 sheep) were bled during the dry and wet seasons. The standard methods used were simple random and jugular venipucture. Standard parasitological methods were used to determine the infection rate. In cattle, the findings showed an infection rate of 11.7% while in sheep it was 17.9%. Peak infection in animals was during the end of the rainy season and beginning of dry season (September-December). Complementary mice inoculation tests revealed 83 sub patent cases and are recommended as a confirmatory diagnostic technique. Afr. J. Clin. Exper. Microbiol. 2004; 5 (3): 221-22

Anaemia in Yankassa Rams Infected with Trypanosoma Congolense, T. Vivax and T. Brucei and their Erythrocytic Responses

One of the most consistent features of trypanosomiasis in any parasite host. The main objective of this study was to therefore evaluate the bone marrow responses to anaemia, generated in Yankassa rams infected with three most common trypanosomes species (T. congolense, T. vivax and T. brucei), affecting Nigerian animals, both at acute and chronic phases.Three groups of Yankassa rams were infected with Trypanosoma congolense, T. vivax and T. brucei, respectively. Each infection group was subdivided into two. While a subgroup was not treated to allow the animals run an acute course, the other subgroup precipitated a chronic course with the application of subcurative doses of diaminazene aceturate. In acute infections, there was a rapid development of anaemia, with PCV dropping down to between 16 and 17%, high parasitaemia in all the subgroups of the three infections, and death, especially in untreated T. brucei subgroup within 5 to 6 weeks of infection. The rapidly developed anaemia in acutely infected animals showed no evidence of increased erythropoiesis in circulation as measured by the level of reticulocytosis in all the three trypanosomal infections. Chronic infections ran for 8-15, 14-20 and 13-20 weeks post treatment in T. congolense, T. vivax and T. brucei infections, respectively. With subsequent relapses after treatment, infected animals had more severe anaemia with the PCV as low as 12 to 13% before death. Increased reticulocytosis developed between 7th and 9th weeks of infections coinciding with periods of low parasitaemia which was earliest with T. brucei infection. This however did not cancel the anaemia developed. Consequently, the reticulocyte responses throughout the infection were suboptimal and could not restore the declining PCV to normal, but at best, just maintained the low levels.Keywords: Erythrocytic response, rams, Trypanosoma congolense acute course, reticulocytosisNigerian Journal of Parasitology, Vol. 32 [1] March 2011, pp.109-11

Acute Respiratory Disease Associated with Mannheimia Haemolytica Infection in a Herd of West African Dwarf Sheep

An acute severe fibrinonecrotic bronchopneumonia suggestive of Mannheimia haemolytica infection was diagnosed histopathologically in West African Dwarf (WAD) sheep submitted to the Veterinary Teaching Hospital (VTH), University of Agriculture, Abeokuta, Nigeria. Mannheimia spp was isolated from the nasal swab and lymph node and lung samples of the affected sheep. The isolated organism was found to have cultural, morphological and biochemical properties consistent with those of Mannheimia haemolytica biotype A. The organism was resistance to ampicilin, streptomycin, gentamcycin, oxytetracyclin and trimethoprim in agar disc diffusion method. It was however sensitive to furazolidone, ciprofloxacin and norfloxacin. The present finding is consistent with the view that M. haemolytica may occur in a proportion of small ruminants that exhibit respiratory problem. It is therefore suggested that in the present natural outbreak, climatic condition, environmental and/or transportation stress could have resulted in the break down of the defense barrier of the sheep resulting in eventual susceptibility to infection by Mannheimia haemolytica.Une bronchopneumonie fibrinon&#233;crotique aigu&#235; s&#233;v&#232;re, &#233;vocatrice d&#8217;une infection &#224; Mannheimia haemolytica, a &#233;t&#233; diagnostiqu&#233;e par examen histopathologique chez des moutons nains d&#8217;Afrique de l&#8217;Ouest (WAD: West African Dwarf) soumis &#224; l&#8217;H&#244;pital d&#8217;enseignement v&#233;t&#233;rinaire (VTH) de l&#8217;Universit&#233; d&#8217;Agriculture d&#8217;Abeokuta au Nigeria. Mannheimia spp a &#233;t&#233; isol&#233;e dans des &#233;couvillons nasaux et des ganglions lymphatiques et des &#233;chantillons pulmonaires des moutons affect&#233;s. On a d&#233;couvert que l&#8217;organisme isol&#233; avait des sp&#233;cificit&#233;s de culture et des caract&#233;ristiques morphologiques et biochimiques correspondant &#224; celles de Mannheimia haemolytica biotype A. L&#8217;organisme a montr&#233; une r&#233;sistance &#224; l&#8217;ampicilline, &#224; la streptomycine, &#224; la gentamcycine, &#224; l&#8217;oxyt&#233;tracycline et au trim&#233;thoprime dans la m&#233;thode de diffusion en g&#233;lose. Cependant, l&#8217;organisme a montr&#233; une sensibilit&#233; &#224; la furazolidone, &#224; la ciprofloxacine et &#224; la norfloxacine. Le pr&#233;sent r&#233;sultat concorde avec l&#8217;opinion selon laquelle M. haemolytica peut &#234;tre pr&#233;sente dans une proportion de petits ruminants ayant un probl&#232;me respiratoire. Il est donc sous-entendu que, dans les &#233;pid&#233;mies actuelles survenant naturellement, les conditions climatiques, le stress environnemental et / ou le stress du transport ont probablement &#233;t&#233; &#224; l&#8217;origine de la d&#233;gradation de la barri&#232;re de d&#233;fense des moutons, avec comme cons&#233;quence une sensibilit&#233; &#233;ventuelle &#224; l&#8217;infection par Mannheimia haemolytica.Mots-cl&#233;s: Pathologie des organes; Mannheimia haemolytica biotype A; Bronchopneumonie fibrinon&#233;crotique aigu&#235;; Moutons nains d&#8217;Afrique de l&#8217;Oues

Hepatic Histopathological Changes in a Dog with Natural Capillaria hepatica Infection in Nigeria

This study describes the appearance of Capillaria (C.) hepatica in an adult dog with a history of fever, which has been previously documented in different parts of the world, yet never in domestic animals in Nigeria. The infection was observed during a retrospective study on the pathology of liver diseases in dogs in the south-western part of the country. Fifty-six formalinised liver tissues of dogs were retrieved and examined from the archives of two veterinary schools and one veterinary clinic. Only one case of C. hepatica infection was found (1.79%). Macroscopically, multiple foci of yellowish-white areas were observed on the hepatic surface. Microscopically, randomly distributed multifocal areas of granuloma-like reactions were observed in the hepatic parenchyma intermingled with Capillaria eggs. The eggs showed characteristic bipolar lids positive for glycoprotein with Periodic acid Schiff andWarthin Starry silver stains. The double-layer shell showed radial striations in the outer shell. Portal and septal fibrosis with closely associated mast cells were also observed. In conclusion, this is the first reported case of the C. hepatica infection in dog in Nigeria. The public health importance of the parasite was also discussed

Reliability of clinical monitoring for the diagnosis of babesiosis in dogs in Nigeria

Olufunke Omowunmi Adebayo,1 Rasheed Adetola Ajadi,2 Temidayo Olutayo Omobowale,3 Samuel Olatunbosun Omotainse,4 Morenike Atinuke Dipeolu,5 Helen Oyebukola Nottidge,3 Ebenezer Babatunde Otesile2 1Veterinary Teaching Hospital, 2Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, Federal University of Agriculture, Abeokuta, 3Faculty of Veterinary Medicine, University of Ibadan, Ibadan, 4Department of Veterinary Pathology, 5Department of Veterinary Public Health and Reproduction, College of Veterinary Medicine, Federal University of Agriculture, Abeokuta, Nigeria Abstract: Babesiosis accounts for a high percentage of hospital cases in canines in Africa, with about 40% mortality in the cases presented. In Nigeria, records show an estimated 30% annual morbidity when diagnosis is largely based on clinical and laboratory findings. This study monitored clinical indices associated with canine babesiosis. One hundred and three babesiosis-suspected dogs were selected on the basis of clinical signs of anorexia, fever, presence of ticks, and enlarged lymph nodes or spleen when clinical parameters were recorded at the time of presentation. Parasite detection was done using thin blood smears; that is, the presence of Babesia merozoites was compared between capillary and cephalic blood. Blood was also assayed for hematology and blood chemistry using automated blood analyzers. The babesiosis-infected dogs&rsquo; outcome was monitored. Data obtained were analyzed using chi-square test, analysis of variance, and Pearson&rsquo;s correlation. Results based on thin blood smears showed that 61.1% of the dogs were positive for Babesia species. Breed disposition, sex, and age did not significantly influence the incidence of Babesia canis, while mean rectal temperatures did not differ significantly between the cases (P&gt;0.05). Heart rate and pulse rates of Babesia-positive dogs were significantly (P&lt;0.05) higher than those that were negative. The packed cell volume between the cases was not significantly different, with the values in the positive and negative case obtained being 26.4% &plusmn;11.26% and 31.6%&plusmn;11.9%, respectively, with a range of 6% to 50% and 10% to 47% observed, respectively. Normal leukogram was also observed in 62% of the Babesia-positive cases while 22.2% and 15.8% had leukocytosis and leukopenia, respectively. Most of the positive cases whose results were based on thin blood smear were treated with 5% oxytetracycline for 5 days and fully recovered. Pearson&rsquo;s correlation was used to give relationship in the observed data. This study concluded that clinical indices are not reliable markers in the diagnosis of canine babesiosis. Keywords: canine babesiosis, Babesia species, dogs, clinical parameters, marker