Seroprevalence estimation and management factors associated with high herd seropositivity for Anaplasma marginale in commercial dairy farms of Puerto Rico

Abstract

A cross-sectional study was conducted to determine individual cow seroprevalence of Anaplasma marginale in adult lactating dairy cattle of Puerto Rico (PR) and to assess the associations of farm management factors on herd seroprevalence. Antibody activity against A. marginale was determined using the MSP-5 competitive enzyme-linked immunosorbent assay. Serum samples were obtained from 2,414 adult lactating dairy cattle from 76 randomly selected commercial dairy farms. Herd seroprevalence ranged from 3 to 100% with an overall individual cow seroprevalence for A. marginale of 27.4%. Factors associated with high herd seropositivity were pasture grazing as the main feed source (OR = 6.5, 95% CI = 1.2-34), observed monkeys on the premises (OR = 13, 95% CI = 1.2-138), use of 11% permethrin (OR = 17, 95% CI = 2.2-129), farmers who attended an acaricide certification program (OR = 0.18, 95% CI = 0.04-0.74), and lack of a fly control program (OR = 5.6, 95% CI = 1.3-24).

Diagnostic Accuracy of Methods for Detecting Anaplasma Marginale Infection in Lactating Dairy Cattle of Puerto Rico

“…This was slightly lower than the MSP-5 cELISA seroprevalence of 27% estimated within this sample 32 and toward the lower end of the range of prevalence reported for the Caribbean region. 5 There was a very low prevalence of cattle positive by direct examination of Wright-Giemsa-stained blood smears (5/2331) suggesting few acute infections and possible endemic stability within some herds on the island.…”

“…32 In brief, commercial dairy farms in Puerto Rico constituted the list frame and were randomly selected after stratification by the 4 major ecological zones of the island and the 3 herd sizes. Lactating cattle within herds were randomly selected based on either a simple random sample or systematically as cattle exited the milking parlor.…”

“…Test procedures were performed according to manufacturer recommendations and have been described in a previous report. 32 An ELISA microplate reader f linked to a computer software program g was used to measure and record optical densities (ODs) at 650 nm. Percent inhibition was calculated as (mean OD of negative control -mean OD of test sera)/(mean OD of negative control) 3 100, and results were interpreted at a cutoff of 30% inhibition.…”

Study of prevalence and associated risk factors of anaplasmosis and theileriasis in cattle

“…Catttle of more than 4 year of age were significantly (P<0.05) at higher risk as compared to <2-4, 1-2 and <1 year age groups (Atif et al, 2013). (Urdaz-Rodriguez et al, 2009;Aubry and Geale, 2011) mentioned seroprevalence increased with age found higher prevalence of anaplasmosis in calves and lowest in young cattle in Uganda and the difference was explained by dominant immune responses to Anaplasma spp. infection.…”

Molecular and serological prevalence of Anaplasma marginale in cattle of North Central Morocco

“…Following transmission, cattle develop rickettsiaemia, accompanied by fever, severe anemia, weight loss, decreased milk production, abortion and sometimes death during acute infections (Kocan et al, 2003;Urdaz-Rodríguez et al, 2009). After the first infection with A. marginale, cattle remain persistently infected carriers and serve as long-term reservoirs for the maintenance of the infection in ticks (Goff et al, 1988;Kocan et al, 1992a,b;Eriks et al, 1993).…”