Bovine Ehrlichiosis Prevalence: A Systematic Review and Meta-Analysis of Molecular Studies

Abstract

While some Ehrlichia species, such as E. ruminantium and E. minasensis, are not popular even among veterinarians, they can infect cattle. The current study aimed to review studies on Ehrlichia spp. to evaluate its worldwide molecular prevalence, given the lack of information about bovine ehrlichiosis and the lack of previous systematic reviews and meta-analyses on this subject. In order to determine the molecular prevalence of Ehrlichia spp. in cattle, a systematic review of the literature was conducted in three databases. A meta-analysis with a random-effects model was performed to calculate the pooled prevalence with 95% confidence intervals (95% CI) and measures of heterogeneity were reported. Subgroup analyses were performed in terms of Ehrlichia species, country, and regions. The literature search yielded 1051 papers until August 1, 2019, with 71 studies entirely eligible for review. The pooled molecular prevalence for Ehrlichia at the individual level (N = 6232) was 2.3% (95% CI: 1.7-2.9%) with the highest value of 82.4%. Studies identified the highest pooled molecular prevalence of 6.6% (95% CI: 0.6-12.7%) for E. canis, followed by E. ruminantium (n = 4695, 75.33%) 52 studies, with 1.7% (95% CI: 1.1-2.3%) and E. chaffeensis with 1.5% (95% CI: 0.0-0.3%). Moreover, the obtained result was indicative of only one study addressing E. minasensis. As the findings suggested, heartwater (E. ruminantium infection) is a notifiable disease of domestic and wild ruminants, recorded by the World Organization for Animal Health. There is a possible risk of endemic heartwater in the Americas due to the climatic features. Furthermore, E. minasensis, E. chaffeensis, and E. canis were observed in cattle although the two last species could be a molecular misidentification with regard to their phylogenetic relationships with E. minasensis.

Seroprevalence canine survey for selected vector-borne pathogens and its relationship with poverty in metropolitan Pereira, Colombia, 2020

“…This study was performed in Colombia, where there is also a lack of seroprevalence studies about Ehrlichia spp. (less than 20 in PubMed database), 11 in canine populations, none in Pereira and Risaralda ( Arroyave et al, 2020b ; Bonilla-Aldana et al, 2021 ; Forero-Becerra et al, 2021 ; Hidalgo et al, 2009 ; McCown et al, 2014 ; Miranda and Mattar, 2015 ; Pesapane et al, 2019 ; Vargas-Hernandez et al, 2012 ). Given the high seroprevalence obtained in an area with ticks' infestation (data not shown), the potential risk for zoonotic transmission to humans remains latent, deserving immediate seroprevalence studies.…”

“…Among the most vulnerable populations for these vector-borne diseases ( Bonilla-Aldana et al, 2021 ) are dogs ( Bonilla-Aldana et al, 2020b ; Rodriguez-Morales et al, 2018a ; Rodriguez-Morales et al, 2018b ). Multiple studies worldwide have assessed the prevalence of such diseases in canine populations ( Petruccelli et al, 2020 ).…”

Dynamics of Infections in Cattle and Rhipicephalus microplus: A Preliminary Study

“…Tick-borne pathogens (TBPs) are a significant problem globally, particularly in tropical and subtropical regions, affecting livestock industries and animal health [ 1 , 2 ]. The main pathogens responsible for productivity loss and health issues in livestock are tick-borne protozoa, namely Babesia ( B. bovis and B. bigemina ) and Theileria ( T. annulata , T. sinensis , and T. orientalis ), as well as tick-borne rickettsial pathogens, such as Anaplasma ( A. marginale , A. bovis , A. centrale , A. phagocytophilum , and A. platys ) and Ehrlichia ( E. ruminantium and E. minasensis ) [ 1 , 3 , 4 ].…”

Detection of Anaplasma and Ehrlichia bacteria in humans, wildlife, and ticks in the Amazon rainforest

“…The diversity of Ehrlichia and Anaplasma bacteria has been investigated mainly in humans and domestic animals 6 , 8 , 9 . This led to the identification of E. chaffeensis as the major Ehrlichia species infecting humans, but E. ewingii and E. muris eauclairensis have also been associated with human ehrlichiosis in North America 3 , 11 , 12 .…”

“…including undifferentiated fever with thrombocytopenia, leukopenia, and ranging from subclinical to life-threatening symptoms associated with multi-organ failure 2,3,5 . Ehrlichiosis and anaplasmosis are also the most common tick-borne diseases of domestic animals [6][7][8][9] . Bovine anaplasmosis causes high morbidity and mortality in cattle herds, with annual economic losses estimated to be over $300 million in the United States and $800 million in Latin America 10 .…”