scholarly journals Combining landscape genomics and ecological modelling to investigate local adaptation of indigenous Ugandan cattle to East Coast fever

2018 ◽  
Author(s):  
Elia Vajana ◽  
Mario Barbato ◽  
Licia Colli ◽  
Marco Milanesi ◽  
Estelle Rochat ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Local Adaptation ◽  
Southern Africa ◽  
East Coast ◽  
Infection Risk ◽  
East Coast Fever ◽  
Theileria Parva ◽  
Indigenous Cattle ◽  
Landscape Genomics ◽  
Tick Resistance

AbstractEast Coast fever (ECF) is a fatal sickness affecting cattle populations of eastern, central, and southern Africa. The disease is transmitted by the tickRhipicephalus appendiculatus, and caused by the protozoanTheileria parva parva, which invades host lymphocytes and promotes their clonal expansion. Importantly, indigenous cattle show tolerance to infection in ECF-endemically stable areas. Here, the putative genetic bases underlying ECF-tolerance were investigated using molecular data and epidemiological information from 823 indigenous cattle from Uganda. Vector distribution and host infection risk were estimated over the study area and subsequently tested as triggers of local adaptation by means of landscape genomics analysis. We identified 41 and seven candidate adaptive loci for tick resistance and infection tolerance, respectively. Among the genes associated with the candidate adaptive loci arePRKG1andSLA2.PRKG1was already described as associated with tick resistance in indigenous South African cattle, due to its role into inflammatory response.SLA2 is part of the regulatory pathways involved into lymphocytes’ proliferation. Additionally, local ancestry analysis suggested the zebuine origin of the genomic region candidate for tick resistance.Author summaryThe tick-borne parasiteTheileria parva parvainfects cattle populations of eastern, central and southern Africa, by causing a highly fatal pathology called “East Coast fever”. The disease is especially severe for the exotic breeds imported to Africa, as well as outside the endemic areas of East Africa. In these regions, indigenous cattle populations can survive to infection, and this tolerance might result from unique adaptations evolved to fight the disease. We investigated this hypothesis by using a method named “landscape genomics”, with which we compared the genetic characteristics of indigenous Ugandan cattle coming from areas at different infection risk, and located genomic sites potentially attributable to tolerance. In particular, the method pinpointed two genes, one (PRKG1) involved into inflammatory response and potentially affecting East Coast fever vector attachment, the other (SLA2) involved into lymphocytes proliferation, a process activated byT. parva parvainfection. Our findings can orientate future research on the genetic basis of East Coast fever-tolerance, and derive from a general method that can be applied to investigate adaptation in analogous host-vector-parasite systems. Characterization of the genetic factors underlying East Coast-fever-tolerance represents an essential step towards enhancing sustainability and productivity of local agroecosystems.

scholarly journals Endemic stability for Theileria parva infections in Ankole calves of the Ankole ranching scheme, Uganda

2004 ◽  
Vol 71 (3) ◽  
Author(s):  
F.M. Kivaria ◽  
C. Heuer ◽  
F. Jongejan ◽  
J. Okello-Onen ◽  
T. Rutagwenda ◽  
...  
Keyword(s):  
East Coast ◽  
Population Based ◽  
Tick Control ◽  
East Coast Fever ◽  
Whole Body ◽  
Theileria Parva ◽  
Indigenous Cattle ◽  
Age Related ◽  
Calf Mortality ◽  
Endemic Stability

A population-based study was carried out on the Ankole ranching scheme in south-west Uganda with the aim of determining the endemic status of Theileria parva infections. For this purpose, the age-related sero-prevalence of T. parva and the specific calf mortality associated with the parasite were assessed. Blood samples were collected from 931 Ankole calves of up to 12 months of age from 81 randomly selected herds. The relationship between rainfall pattern and whole-body Rhipicephalus appendiculatus counts was determined. The influence of tick control practices on East Coast fever-related calf mortality, and sero-positivity were also determined. A significant (r2 = 0.76, P = 0.000) association between R. appendiculatus counts and rainfall was observed. There was no significant (P > 0.05) association between theileriosis- related calf mortality, sero-positivity and the different tick control practices. Antibody prevalence based on the PIM ELISA was above 70 % among calves of 6 months of age in 96 % in all the herds. Theileria parva-related calf mortality determined by repeated herd visits and farm records ranged between 0% and 5.4 %. It was concluded that endemic stability for theileriosis, caused by T. parva, existed in the study area, and that the risk of the occurrence of economically important outbreaks of East Coast fever in indigenous cattle was regarded as minimal under the prevailing conditions.

Theileria parva: influence of vector, parasite and host relationships on the epidemiology of theileriosis in southern Africa

Parasitology ◽  
1991 ◽  
Vol 102 (3) ◽  
pp. 347-356 ◽  
Author(s):  
R. A. I. Norval ◽  
J. A. Lawrence ◽  
A. S. Young ◽  
B. D. Perry ◽  
T. T. Dolan ◽  
...  
Keyword(s):  
Southern Africa ◽  
East Coast ◽  
Serial Passage ◽  
Ixodid Tick ◽  
Climatic Conditions ◽  
East Coast Fever ◽  
Control Measures ◽  
Eastern Africa ◽  
Theileria Parva ◽  
Vector Population

The protozoan parasite Theileria parva, transmitted by the ixodid tick Rhipicephalus appendiculatus, is the cause of East Coast fever (ECF) and the related syndromes of Corridor disease and January disease in cattle of eastern, central and southern Africa. It is likely that buffalo (Syncerus caffer) are the natural host of T. parva. In eastern and southern Africa, there exist both buffalo-adapted and cattle-adapted T. parva. Disease caused by buffalo-adapted parasites is called Corridor disease, and that caused by cattle-adapted parasites is termed East Coast fever. In eastern Africa, it has been shown experimentally that buffalo-adapted T. parva can, after serial passage in cattle, become adapted to cattle, in which it can then be maintained and cause ECF. This adaptation has been termed transformation. The transformation of buffalo-adapted T. parva to a cattle-adapted parasite has not been reported in southern Africa, and ECF, eradicated from South Africa, Swaziland and southern Mozambique by 1960, has not reappeared in the subcontinent. This paper discusses the possible reasons for this, and hypothesizes that vector population dynamics and the susceptibility of the vector population to infection with T. parva are among the most important factors which influence the expression of ECF as a disease entity, and the likelihood of transformation occurring. It also considers the possibility that disappearance of ECF from southern Africa resulted from the extinction, as a result of vigorous control measures and unfavourable climatic conditions, of non-diapausing populations of R. appendiculatus that may have been introduced from eastern Africa with cattle imported in 1901.

Theileria parva, the Parasite of East Coast Fever in Cattle

Parasitology ◽  
1910 ◽  
Vol 3 (2) ◽  
pp. 117-129 ◽  
Author(s):  
George H. F. Nuttall ◽  
H. B. Fantham
Keyword(s):  
Peripheral Blood ◽  
East Coast ◽  
East Coast Fever ◽  
Theileria Parva ◽  
The Subject

In an earlier paper (Nuttall, Fantham and Porter, 1909, Parasitology vol II. pp. 325—340), we recorded our observations on living Theileria parva as seen in the peripheral blood of two cows which succumbed to East Coast Fever1. We now propose to describe our studies upon the parasite in stained preparations made from the animals' blood during the course of the disease and from their organs shortly after death. We shall confine our attention to the types of parasites encountered within red blood corpuscles or to corresponding types which may be occasionally encountered free in the plasma. The subject of “Koch's blue bodies” will receive attention at a later date.

East Coast Fever

2021 ◽  
pp. 195-220
Author(s):  
Sammy Gichuhi Ndungu ◽  
Sebastian K. Waruri ◽  
James M. Wanjohi
Keyword(s):  
Southern Africa ◽  
East Coast ◽  
Protozoan Parasite ◽  
Rhipicephalus Appendiculatus ◽  
East Coast Fever ◽  
Therapeutic Drugs ◽  
Major Constraint ◽  
Drug Companies ◽  
Ear Tick ◽  
The Cost

East coast fever, a disease of cattle caused by the protozoan parasite Theileria parva and transmitted by the three-host tick Rhipicephalus appendiculatus (the brown ear tick), is a major constraint to cattle production in Eastern, Central, and Southern Africa. In Kenya it is the most important tick-borne disease and a major constraint in cattle productivity. This is due to the high morbidity and mortality it causes in susceptible herds, the cost of control of the vector ticks, and the cost of treatment of clinical cases. Animals that recover from the disease also suffer from reduced productivity which can be long term. The limited distribution of the tick and the disease to only East, Central and Southern Africa also means that the market for therapeutic drugs and acaricides is small. Therefore, drug companies are not keen on funding research and development of new drug and acaricide molecules when resistance occurs.

scholarly journals Observations on Theileria parva, the Parasite of East Coast Fever of Cattle

Parasitology ◽  
1909 ◽  
Vol 2 (4) ◽  
pp. 325-340 ◽  
Author(s):  
George H. F. Nuttall ◽  
H. B. Fantham ◽  
Annie Porter
Keyword(s):  
East Coast ◽  
Causal Relation ◽  
Good Deal ◽  
East Coast Fever ◽  
Theileria Parva ◽  
New Disease ◽  
Marked Contrast ◽  
Infected Blood ◽  
The One ◽  
Fever Reaction

Although a good deal has been written about East Coast Fever in cattle, the literature relating thereto contains very little direct information regarding the parasite which stands in causal relation to the disease. Robert Koch (1898), who was the first to observe the parasite in cases of East Coast Fever occurring in German East Africa, regarded it as but a variety of Piroplasma bovis (= bigeminum) and described the disease as Texas Fever. Theiler (1904) was the first to distinguish clearly East Coast Fever from Redwater. He stated that “the disease has nothing to do with Texas Fever or Redwater; it is a new disease due to a parasite different to the one found in Texas Fever.” Koch (1903—1904), who gave the disease its distinctive name, reached the same conclusions as Theiler. The investigations of Theiler (1904) established the following facts: Cattle which are immune to Redwater are susceptible to East Coast Fever. East Coast Fever is not communicable by blood inoculations (30 experiments, wherein 5 to 2000 c.c. of East Coast Fever blood were inoculated). He noted the absence of haemoglobinuria in the majority of animals affected with East Coast Fever, its presence in the majority of the animals affected with Redwater. He found that in most cases of East Coast Fever, there was no appreciable decrease in the number of red blood corpuscles, this being in marked contrast to what is observed in Redwater. Theiler noted that cattle might harbour both the parasites of Redwater (P. bovis) and those of East Coast Fever (bacillary forms = T. parva). The former generally appeared in the blood “only towards the end of the fever reaction in East Coast Fever,” being previously latent in the animals which had been “salted” against Redwater. He distinguished “two groups of piroplasmosis,” the inoculable (Redwater, canine and equine piroplasmosis) and the uninoculable (East Coast Fever) by injection of infected blood. The parasites in the latter are much smaller than in the former. He named the parasites of East Coast Fever Piroplasma parvum. Theiler distinguished the parasite of East Coast Fever from P. bovis because of the frequent occurrence of bacillary forms and the minute size of the parasite, but he nevertheless retained the new parasite in the genus Piroplasma.

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