Skip to main content
NCBI home page
Parasitology logoLink to Parasitology
. 2024 Nov 15;151(9):992–1000. doi: 10.1017/S0031182024001495

First seroprevalence survey of bovine anaplasmosis: an emerging tick-borne disease in commercial livestock and dairy farms in Bangladesh

Md Makshuder Rahman Zim 1, Nurnabi Ahmed 1, Mostak Ahmed 1, Md Abu Haris Miah 2, Md Mahfuzur Rahman Sajib 1, Md Rajiur Rahaman Rabbi 1, Md Khalilur Rahman 1, Babul Chandra Roy 1, Md Hasanuzzaman Talukder 1,✉
Editor: Ala Tabor
PMCID: PMC11770521  PMID: 39721809

graphic file with name S0031182024001495_figAb.jpg

Open in a new tab

Keywords: anaplasmosis, cattle, cELISA, seroprevalence, tick-vector

Abstract

Bovine anaplasmosis is an infectious, tick-borne disease caused by Anaplasma species, which is accountable for huge economic loss in dairy industry. This study was aimed to determine the seroprevalence of bovine anaplasmosis on randomly selected 61 commercial dairy farms in 3 intensive regions of Bangladesh. A total of 1472 sera were analysed using VMRD Anaplasma Antibody Test Kit cELISA v2 for the presence of Anaplasma-specific antibodies. The highest regional seroprevalence of Anaplasma was 45.93% in individual level and 74.4% in herd level recorded in the southeast region, whereas it was 48.8% in individual level and 83.3% in herd level in Khagrachari and Sherpur districts, indicating an emerging state of the disease. The herd size and type in herd level and regions, districts, sex, age and breed in individual level were significantly (P ≤ 0.05) associated with anaplasmosis. Multivariate logistic regression analysis showed that cattle aged >1 year had 1.86 times higher odds compared to cattle younger than 1 year. Dairy cows had the highest odds (2.25) of anaplasmosis, followed by dairy heifers (1.68), compared to bulls. Compared to herd sizes of <4, the odds of Anaplasma infection were 11.3 and 7.45 times greater in herd sizes of >28 and 4–28. Crossbred cattle had 2.4 times higher odds of anaplasmosis compared to indigenous cattle. This first seroprevalence study signifies the widespread presence and underscores the importance of monitoring and managing anaplasmosis to safeguard cattle health in Bangladesh. Study on the molecular epidemiology and genetic diversity of Anaplasma among cattle populations should be prioritized.

Introduction

Bovine anaplasmosis is a highly transmissible tick-borne disease that affects cattle and other ruminants (Watthanadirek et al., 2019), primarily caused by Anaplasma marginale. The disease is endemic in tropical and subtropical regions worldwide, causing significant health issues and economic losses in the livestock industry. Other species of Anaplasma, such as A. centrale, A. bovis and A. phagocytophilum, also cause various forms of the disease in cattle (Ybañez and Inokuma, 2016). Transmission of Anaplasma species occurs through biological vectors (ticks), mechanical vectors (biting flies, fomites) (Radostits and Done, 2007; Kocan et al., 2010; Aubry and Geale, 2011) and rarely through the placenta (Van Loo et al., 2023). Approximately, 20 tick species have been reported as vectors of A. marginale globally (Radostits and Done, 2007); however, Rhipicephalus microplus was identified as a main natural vector in Bangladesh (Roy et al., 2018). Biological vectors can maintain and propagate A. marginale for a significant length of time, making them crucial for disease transmission. However, some strains of A. marginale may rely on rapid mechanical transfer due to the limited quantity of the agent transferred (Kocan et al., 2010; Aubry and Geale, 2011).

Anaplasmosis is clinically characterized by showing general weakness, weight loss, fever, severe anaemia, pale mucous membranes, abortion, lethargy, icterus, decreased milk production and often death in animals older than 2 years (Kocan et al., 2015). The severity of the disease depends on some factors, such as the host's immunological state and the presence of other pathogens (Constable et al., 2017). Recovered cattle may develop persistent infection which is considered an important epidemiological factor for bovine anaplasmosis. It has been observed that recovered cattle from acute cases, even those that have been treated with the recommended doses of tetracycline, continue to maintain a microscopically undetectable parasitaemia for their entire lives (Palmer et al., 2000; Radostits and Done, 2007; Kocan et al., 2010; Aubry and Geale, 2011). Persistently infected cattle that are exposed to mechanical and/or biological vectors can act as reservoirs of infection to introduce A. marginale into naive cattle populations (de Echaide et al., 2001; Futse et al., 2003).

Bangladesh has around 25.7 million cattle, demonstrating the importance of dairy and meat production in the country (World Bank, 2018). Bovine anaplasmosis has a severe economic impact on the dairy industries by reducing weight gain, milk and meat production, abortion, icterus and even death (Hove et al., 2018; Okafor et al., 2018). Several studies have been carried out previously on the subclinical and clinical bovine anaplasmosis in Bangladesh (Samad et al., 1989; Talukder and Karim, 2001). A higher frequency of subclinical anaplasmosis (33%) was detected in the milk vita region of Sirajganj district (Talukder and Karim, 2001). On the other hand, 70% anaplasmosis was detected in cattle with possible clinical signs (Chowdhury et al., 2006), and 1% prevalence of haemoprotozoan parasites was reported in Red Chittagong Cattle of Chattogram district (Siddiki et al., 2010), 22.74% in Sylhet (Akter et al., 2018) and 18.67% in Sirajganj (Islam et al., 2019) based on the microscopic examination of Giemsa-stained blood smear. About 43% prevalence of bovine anaplasmosis was detected in Dhaka (Hassan et al., 2019), 15.75% in Chattogram (Mannan et al., 2022) and 82.86% in Bandarban (Mohanta et al., 2023) through polymerase chain reaction (PCR). Although several epidemiological studies have been performed on bovine anaplasmosis in different regions of Bangladesh based on the microscopic examination of Giemsa-stained blood smears and PCR, the seroprevalence of bovine anaplasmosis has not yet been addressed in Bangladesh. The competitive enzyme-linked immunosorbent assay (cELISA) test is advised for population monitoring and screening, whereas PCR and microscopic examination of blood smears are advised for the investigation of clinical cases, according to diagnostic assays used in veterinary medicine for the detection of A. marginale and A. centrale. Currently, the prevalence of bovine anaplasmosis and its economic consequences have become a concerned issue in the country. Climate change, vector diversity and diverse geographical areas are making the situation more critical to control disease transmission and prevention. Knowledge regarding the local or regional prevalence of bovine anaplasmosis is required for the effective implementation of control strategies. In order to execute effective management programmes of bovine anaplasmosis in Bangladesh, it is imperative to determine the seroprevalence, which may serve as a lookout for estimating the prevalence of the disease in the study area.

The present study investigated the seroprevalence of bovine anaplasmosis in commercial dairy farms in the northeast, central and southeast regions of Bangladesh using cELISA to provide comprehensive data to the scientific community for future planning to control the disease. The geographical locations of the 3 zones are characterized by plain, hilly and riverine areas. Therefore, the present study was conducted for the first time in Bangladesh to monitor the health status of livestock animals to detect the presence of Anaplasma infections by serological assay.

Materials and methods

Study area

The study was conducted in 3 dairy intensive regions of Bangladesh, viz., northeast, central and southeast regions (Fig. 1), from October 2022 to March 2024. The northeast region includes Mymensingh, Sherpur, Jamalpur and Netrakona districts, whereas the southeast region comprises Chattogram and Khagrachari districts and Dhaka, Gazipur and Narsingdi districts belong to the central region, respectively. These selected districts were promising for crossbreed dairy farming because of the growing demand for food derived from animals, the high density of the cattle population, the great potential for productivity enhancement, the agro-ecological conditions that support the production of feed, the accessibility of crop residues and the option of mixed crop–livestock farming (World Bank, 2018). The study area had more than one-third of the cattle farms of Bangladesh combined (Huque and Khan, 2017) and the list of dairy farms was obtained from sub-district (Upazila) livestock offices posted in the respective district. The list of farms (sampling frame) from these districts of Bangladesh was entered into a spreadsheet (Microsoft Excel 2010). Each farm was assigned an Excel-generated random number using the ‘rand’ function, and 61 farms were selected. Then the herds were randomly selected from the sampling frame (Islam et al., 2020). The farms with 2 cattle and at least 1 mature cattle were considered as an inclusion criterion for this study. All animals on the farm were included in the study, including weak and emaciated animals, with the exception of calves under 6 months of age and those in advanced pregnancy (>8 months). Geographic coordinates of each selected cattle farm were captured during blood sample collection using a handheld global positioning system reader (Garmin eTrex 10) (Islam et al., 2020). ArcGIS-ArcMap version 10.3 (Environmental System Research Institute, Redlands, CA, USA) was used to visualize the spatial distribution of the cattle farms included in this study (Rahman et al., 2015).

Figure 1.

Figure 1.

Open in a new tab

Map of the study districts of Bangladesh. A total of 61 cattle farms of 9 districts were surveyed; black circles are the GIS coordinates of selected farm.

Calculation of sample size and sampling procedure

The sample size was determined by Cochran's sample size formula (Cochran, 1977) for categorical data for an α level a priori at 0.05 (error of 5%), n0 = (t)2*(p)(q)/(d)2 [where: n0 is the sample size; t is the value for the selected α level, e.g. 1.96 for (0.25 in each tail) a 95% confidence level; p (5%) is the expected proportion of an attribute that is present in the population; q is 1−p; (p) (q) are the estimates of variance; d is the acceptable margin of error for the proportion being estimated, so the confidence interval, in decimals). A total of 1472 blood samples (552 samples from the northeast, 442 from the southeast and 478 samples from the central regions) were obtained from 61 commercial dairy farms in these 3 study regions.

Blood collection

Prior to collection of blood samples, farm owners' oral consent was obtained. From each cattle, 8 mL of blood was withdrawn via jugular venipuncture with disposable needles and 6 mL of blood was put into serum collection tubes, labelled and transferred to the laboratory of the Department of Parasitology, BAU, on ice (after clotting) within 12 h. Sera were extracted 1 day later by centrifuging at 3000×g for 30 min, after which blood samples were kept refrigerated (2–8°C) in the laboratory. Each serum sample was labelled with the animal's identification number and stored at −20°C.

Serological study using cELISA

All serum samples (1472) were analysed for the presence of Anaplasma-specific antibodies using a commercially available cELISA kit (Veterinary Medical Research and Development Inc., Pullman, WA, USA) according to the manufacturer's instructions and published literature (Parvizi et al., 2020). The wells of the ELISA plates were coated with Anaplasma spp. antigen provided with the commercial kits. The commercial kits included both positive and negative control sera for this assay. The optical densities of the samples were measured at 620 nm using an ELISA reader. The inhibition per cent was computed as I% = 100 (1 [sample OD620/OD620 of the negative control]) to understand the results. Any sample with <30 and ⩾30% was considered negative and positive, respectively. The manufacturer states that the test has >99% specificity and sensitivity with this cut-off. If a single animal was positive for Anaplasma infection, we considered the herd as positive (Islam et al., 2020).

Data management and analysis

Animal, farm-level data and laboratory findings were entered into a spreadsheet (Microsoft Excel 2010). The dataset was coded, checked, validated for integrity and exported to SPSS Statistics software®, which was used to analyse the data (IBM Corp., Armonk, NY, USA, version 25). We calculated the mean and standard deviation (s.d.) for continuous variables and calculated proportions and frequency distributions for categorical variables. All continuous predictor variables [herd size, age of the animal, sex, breed and cattle raised for various purposes (calf, dairy heifer, beef heifer, bull and dairy cows)] were categorized prior to logistic regression analysis. Initially, univariable mixed-effects logistic regression analyses were performed to find out the effect of individual risk factors on Anaplasma infection. The variables that were statistically significant (P < 0.05) in the univariate analysis were selected as potential candidates for the multivariable analysis to find out the interaction of different variables. A backward stepwise elimination approach was applied in the multiple logistic regression. Variables with a P value <0.05 were retained in the final mixed-effects logistic regression model. Collinearity among explanatory variables was assessed by Cramer's phi-prime statistic and a pair of variables was considered collinear if Cramer's phi-prime statistic was >0.70 (Rahman et al., 2017).

Results

Descriptive epidemiology

A total of 1472 dairy cattle from 61 randomly selected dairy farms, with a herd size of 126 (interquartile range, IQR), across 3 regions were sampled in the investigation. Overall, 42.93% of the cattle were recorded as seropositive in the study. The majority of the sampled cattle (37.5%) were from the northeast region, followed by the central region (32.5%) with the southeast region contributing the smallest proportion (30%) (Table 1). The highest number of seropositive animals was found in the northeast region (n = 221). In this study, the majority of cattle were sampled from Mymensingh (21%), followed by Chattogram (18.5%), Gazipur (13.7%), Khagrachari (11.5%), Dhaka (11%), Jamalpur (7.6%), Narsingdi (7.4%), Netrakona (5%) and Sherpur (3.7%). Mymensingh district recorded the highest number of seropositive animals (n = 138). Two-thirds (73.4%) of the sampled cattle were female, with females showing higher seropositivity, accounting for 482 of the seropositive cases. The age distribution of the population under study was nearly equal. Cattle older than 1 year exhibited a higher number of seropositive cases (n = 348). Calves, which comprised 48.2% of the total population, had the highest number of seropositive cases (n = 284) among all animals. Among adult cattle, dairy cows showed the highest seropositivity (n = 202). The majority of the sampled cattle were crossbred (75.82%), with a total of 507 seropositive cases in this group (Table 1).

Table 1.

Overall status of seroprevalence on different animal-level parameters in cattle (N = 1472) in the study areas of Bangladesh

Parameters Total animals
N (%)		 Seropositive animals
n 		Overall seroprevalence (%) 95% confidence interval
Regions
Northeast 552 (37.5) 221 15.01 13.19–16.83
Central 478 (32.5) 208 14.13 12.35–15.91
Southeast 442 (30.0) 203 13.79 12.03–15.55
Districts
Dhaka 167 (11) 63 4.28 3.25–5.31
Gazipur 202 (13.7) 97 6.59 5.32–7.86
Narsingdi 109 (7.4) 48 3.26 2.365–4.17
Mymensingh 310 (21) 138 9.38 7.89–10.87
Jamalpur 112 (7.6) 38 2.58 1.77–3.39
Sherpur 55 (3.7) 22 1.49 0.87–2.11
Netrakona 75 (5) 23 1.56 0.93–2.19
Chattogram 272 (18.5) 120 8.15 6.75–9.55
Khagrachari 170 (11.5) 83 5.64 4.47–6.83
Sex
Male 392 (26.6) 150 10.19 8.64–11.74
Female 1080 (73.4) 482 32.74 30.34–35.14
Age
<1 year 710 (48.2) 284 19.29 17.27–21.31
>1 year 762 (51.8) 348 23.64 21.47–2581
Herd type
Calf 710 (48.2) 284 19.29 8.64–11.74
Dairy heifer 222 (15.1) 97 6.58 5.31–7.85
Beef heifer 26 (1.8) 8 0.54 0.17–0.91
Bull 126 (8.6) 41 2.79 1.95–3.63
Dairy cow 388 (26.3) 202 13.72 11.96–15.48
Breed
Crossbred 1116 (75.82) 507 34.44 32.01–36.87
Local 356 (24.18) 125 8.49 7.07–9.91
Overall
Total 1472 (100) 632 42.93 40.40–45.46
Open in a new tab

Herd- and individual-level seroprevalence of anaplasmosis

Regional seroprevalence

In the study, an overall herd-level seroprevalence of 70.6% (n = 89) was observed, while the individual cattle-level seroprevalence was 42.93% (n = 692). Among the 3 regions, the highest herd-level seroprevalence of anaplasmosis was observed in the southeast region (74.4%, n = 29), followed by the central (69.8%, n = 30) and northeast (68.2%, n = 30) regions (Table 2). At the individual cattle level, the southeast region also had the highest seroprevalence (45.93%, n = 203), followed by the central (43.51%, n = 208) and northeast (40.04%, n = 221) regions (Table 2). The results indicated that the cattle populations in the southeast, central and northeast regions of Bangladesh exhibited a high seroprevalence of Anaplasma infections. This widespread presence underscores the importance of monitoring and managing Anaplasma infections to safeguard cattle health in these regions.

Table 2.

Seroprevalence of Anaplasma infections among different regions of Bangladesh diagnosed by competitive enzyme-linked immunosorbent assay (cELISA)

Regions Total number of farms Herd levels Individual animal levels
Positivity % n/N 95% CI Positivity % n/N 95% CI
Northeast 17 68.2 (30/44) 64.8–71.3 40.04 (221/552) 35.92–44.30
Central 26 69.8 (30/43) 63.3–68.7 43.51 (208/478) 39.02–48.10
Southeast 18 74.4 (29/39) 69.9–78.1 45.93 (203/442) 40.46–45.60
Total 61 70.6 (89/126) 62.7–78.6 42.93 (632/1472) 40.40–45.46
Open in a new tab

CI, confidence interval; n/N, number of positive/number of examined.

District-level seroprevalence

Among the districts, Sherpur district had the highest herd-level seroprevalence (83.3%, n = 5), followed by Gazipur district (81.8%, n = 9), despite the small herd sizes in both cases. Beyond these, Chattogram (80.8%, n = 21) exhibited the highest seroprevalence, followed by Mymensingh (75%, n = 18), Dhaka (73.7%, n = 14), Jamalpur (57.14%, n = 4) and Netrakona (50%, n = 3) districts and Khagrachari (61.5%, n = 8) exhibited the lowest herd-level seroprevalence, respectively (Table 3). Additionally, at individual cattle level, the highest percentages of seropositive cattle were recorded in Khagrachari (48.8%, n = 83), followed by Gazipur (48%, n = 97), Mymensingh (44.5%, n = 138), Chattogram (44.4%, n = 120), Narsingdi (44%, n = 48), Sherpur (40%, n = 22), Dhaka (37.7%, n = 63), Jamalpur (33.9%, n = 38) and Netrakona (30.7%, n = 23) districts, respectively (Table 3).

Table 3.

Seroprevalence of Anaplasma infections among different districts diagnosed by competitive enzyme-linked immunosorbent assay (cELISA)

Herd level Individual animal level
Factors Districts Total number of farms Positivity % n/N 95% CI Positivity % n/N 95% CI
Zones
Central Dhaka 6 73.7 (14/19) 69.3–74.7 37.7 (63/167) 30.35–45.05
Gazipur 6 81.8 (9/11) 79.6–84.4 48.0 (97/202) 41.11–54.89
Narsingdi 6 50.0 (7/14) 48.4–51.6 44.0 (48/109) 34.68–53.32
Northeast Mymensingh 9 75.0 (18/24) 70.6–79.4 44.5 (138/310) 38.97–50.03
Jamalpur 7 57.14 (4/7) 51.1–62.9 33.9 (38/112) 25.13–42.67
Sherpur 6 83.3 (5/6) 74.2–91.8 40.0 (22/55) 27.05–52.95
Netrakona 6 50.0 (3/6) 46.8–53.2 30.7 (23/75) 20.26–41.14
Southeast Chattogram 9 80.8 (21/26) 76.8–85.2 44.4 (120/272) 38.50–50.30
Khagrachari 6 61.5 (8/13) 59.3–64.7 48.8 (83/170) 41.29–56.31
Total 61 70.6 (89/126) 62.7–78.6 42.93 (632/1472) 40.40–45.46
Open in a new tab

CI, confidence interval; n/N, number of positive/number of examined.

Bovine anaplasmosis risk factors in individual cattle level

At the individual cattle level, regions, districts, sex, age, herd type, herd size and breed were all significantly (P ⩽ 0.05) associated with anaplasmosis (Table 4). The regional- and district-level seroprevalence is described in the previous sections of the study. The southeast region and Khagrachari district had the highest seroprevalence, with both being significantly associated (P = 0.05) with higher rates of infection (Table 4). Additionally, the univariable analysis revealed that female animals had a significantly (P = 0.04) higher prevalence of Anaplasma infections (44.6%, n = 482) compared to male animals (38.3%, n = 150). A higher prevalence of Anaplasma infections was recorded in cattle older than 1 year (45.7%, n = 348), while a lower prevalence was observed in cattle younger than 1 year (40%, n = 284) (Table 4). The present study was carried out on different cattle herd types, i.e. calves, dairy heifers, beef heifers, bulls and dairy cows among the cattle population in the study areas. The results of univariate analysis indicated that Anaplasma infections were significantly (P = 0.0001) more prevalent in dairy cows (52.1%, n = 202) and dairy heifers (43.7%, n = 97), followed by calves (40%, n = 284), bulls (32.5%, n = 41) and beef heifers (30.8%, n = 8), respectively (Table 4). The herd size of animal farms was significantly (P⩽0.05) associated with anaplasmosis, as revealed by univariable logistic regression analysis. The seroprevalence of Anaplasma infection was significantly (P = 0.002) higher in herds with more than 28 animals (81.1%, n = 30) compared to herds with fewer than 4 animals. It was also significantly (P = 0.01) higher in herds with 4–28 animals (72.6%, n = 53). The study also revealed that crossbred animals had a significantly (P = 0.001) higher seroprevalence of Anaplasma infection (45.4%, n = 507) compared to indigenous cattle breeds (35.4%, n = 125) (Table 4).

Table 4.

Univariate logistic regression analysis between demographic characteristics and Anaplasma seroprevalence among cattle in different selected dairy farms in Bangladesh

Variables Total number of animals (N) Seroprevalence (%) positive No. (n) Odd ratio (95% CI) P value
Regions
Northeast 552 40.04 (221) Reference –
Central 478 43.51 (208) 1.16 (0.9–1.48) 0.28
Southeast 442 45.93 (203) 1.29 (1–1.65) 0.05*
Districts
Dhaka 167 37.7 (63) Reference –
Gazipur 202 48.0 (97) 0.99 (0.63–1.54) 1
Narsingdi 109 44.0 (48) 1.3 (0.79–2.12) 0.35
Mymensingh 310 44.5 (138) 1.29 (0.88–1.89) 0.23
Jamalpur 112 33.9 (38) 0.84 (0.6–1.40) 0.6
Sherpur 55 40.0 (22) 1.8 (0.64–2.2) 0.7
Netrokona 75 30.7 (23) 0.78 (0.43–1.38) 0.47
Chattogram 272 44.4 (120) 1.3 (0.9–1.96) 0.2
Khagrachari 170 48.8 (83) 1.6 (1.02–2.43) 0.05*
Sex
Male 392 38.3 (150) Reference –
Female 1080 44.6 (482) 1.29 (1.01–1.62) 0.04*
Age
<1 year 710 40.0 (284) Reference –
>1 year 762 45.7 (348) 1.26 (1.03–1.55) 0.03*
Herd type
Calf 710 40.0 (284) 1.22 (0.94–1.61) 0.13
Dairy heifer 222 43.7 (97) 1.34 (1.00–1.79) 0.04*
Beef heifer 26 30.8 (8) 0.94 (0.50–1.77) 0.86
Bull 126 32.5 (41) Reference –
Dairy cow 388 52.1 (202) 1.59 (1.22–2.09) 0.0001*
Herd size
Small herd (<4) 16 37.5 (6) Reference –
Medium herd (4-28) 73 72.6 (53) 4.42 (1.42–13.75) 0.01*
Large herd (>28) 37 81.1 (30) 7.14 (1.94–26.32) 0.002*
Breed
Indigenous 356 35.4 (125) References –
Crossbred 1116 45.4 (507) 1.54 (1.2–1.97) 0.001*
Open in a new tab

CI, confidence interval.

*Significant at P ⩽ 0.05 level.

Regions and districts with age groups and herd types with sex groups were collinear (Cramer's phi-prime statistic >0.70). Therefore, regions, districts and sex were excluded from the multivariable logistic regression analysis. The odds ratio (OR) of anaplasmosis was significantly (P = 0.01) higher in cattle aged >1 year, with an OR of 1.86 (95% CI 1.4–3.1), compared to cattle aged <1 year (Table 5). For herd type, significantly (P = 0.001) dairy cows had the highest odds of Anaplasma infection (2.25 times, 95% CI 1.48–3.44) followed by dairy heifer (1.68 times, 95% CI 1.02–2.54), compared to bulls. Compared with a herd size of <4, the odds of Anaplasma infection were significantly (P ≤ 0.001) 11.3 (95% CI 7.9–28.2) and 7.45 times (95% CI 4.6–21.56) greater in herd sizes of >28 and 4–28, respectively. Crossbred cattle had significantly (P = 0.001) higher odds of Anaplasma infection, increasing the risk by 2.4 times (95% CI 1.68–3.94) compared to indigenous (Bos indicus) cattle (Table 5).

Table 5.

Multivariate logistic regression analysis of important variables (P < 0.05) after collinearity checking associated with Anaplasma seroprevalence among cattle in different selected dairy farms in Bangladesh

Variables Total seropositive animals
(n)		 Odd ratio (95% CI) P value
Age
<1 year 284 Reference
>1 year 348 1.86 (1.4–3.1) 0.01*
Herd type
Bull 41 Reference –
Dairy heifer 97 1.68 (1.02–2.54) 0.02*
Dairy cow 202 2.25 (1.48–3.44) 0.001*
Herd size
Small herd (<4) 06 References
Medium herd (4–28) 53 7.45 (4.6–21.56) <0.001*
Large herd (>28) 30 11.3 (7.9–28.2) <0.001*
Breed
Indigenous 507 References
Crossbred 125 2.4 (1.68–3.94) 0.001*
Open in a new tab

CI, confidence interval.

*Significant at P ⩽ 0.05 level.

Discussion

Anaplasma is a tick-borne pathogen that can cause disease in cattle, leading to economic losses in the livestock industry (Rodríguez et al., 2009). In developing countries like Bangladesh, where there may be limited resources for tick control and veterinary care, bovine anaplasmosis becomes a major problem. This is the first seroprevalence report of Anaplasma infections in the cattle population of Bangladesh. In this study, we estimated seroprevalence of Anaplasma based on the herd and cattle level in the 9 intensive dairy rearing districts of Bangladesh and identified risk factors for Anaplasma infection in cattle.

The study revealed that the seroprevalence of anaplasmosis at regional level varied from 40 to 46% in individual cattle level and 66 to 74% at herd level and the highest seropositivity was found in the southeast region for both cases. In addition, seropositivity was between 32 and 49% at the individual cattle level, while it was 50 and 83% at the herd level in 9 study districts. The study revealed that cattle from Khagrachari, Gazipur, Chattogram and Mymensingh had high seropositivity. This suggests that these animals have had previous or ongoing infections with Anaplasma spp. The seroprevalence of the Anaplasma infection in the present study was consistent with those reported previously from the neighbouring country, India, particularly in southern Rajasthan, India, where the seropositivity was 42.28% in cattle and 48.72% in organized cattle herds, respectively (Sharma et al., 2015; Sarangi et al., 2021). Another seroprevalence study reported 34 and 46% seropositivity for bovine anaplasmosis in India and globally (Paramanandham et al., 2019). However, the present study findings conflicted with those reports, where seropositivity of Anaplasma infection was 15.02% in Texas (Hairgrove et al., 2014) and 18.5% in Egypt (Parvizi et al., 2020), respectively.

At the individual cattle level, regions, districts, sex, age and breed were identified as potential risk variables for Anaplasma infection test-positivity, while herd type and herd size were identified as risk variables at the herd level. In the present study, age was determined to be one of the potential risk variables for bovine anaplasmosis. The seroprevalence of Anaplasma infections in cattle aged >1 year had around 2 times higher odds of bovine anaplasmosis compared to that of cattle aged <1 year. The findings were in line with other previous published reports where Anaplasma infections increase significantly with age and have the highest prevalence in adults more than 1 year old (Chowdhury et al., 2006; Kocan et al., 2010; Alim et al., 2012; Atif et al., 2012). This higher seropositivity in adults compared to young animals might be due to a higher chance to pick up the Anaplasma infection as they stay on the farm longer than male cattle. However, these findings conflict with those reports where anaplasmosis was more common in young animals than in adult cattle (Nazar et al., 2018; Khan et al., 2019).

In this study, breed was also identified as a potential risk for the occurrence of Anaplasma infections in cattle. Crossbred cattle are 2.4 times more prone to anaplasmosis compared to local/indigenous cattle. The present finding was consistent with the previous reports on anaplasmosis, highlighting the vulnerability of crossbred cattle to Anaplasma infections (Ananda et al., 2009; Siddiki et al., 2010). In addition, previous reports observed a higher prevalence of infection in exotic breeds and their crosses compared to local breeds of cattle (Chowdhury et al., 2006; Atif et al., 2012; Farooqi et al., 2018; Khan et al., 2019; Shoaib et al., 2021). This is attributed to the fact that exotic breeds and their crosses are more susceptible to tick infestation. The lower frequency in indigenous cattle could be due to constant exposure to diseases, leading to the development of immunity against Anaplasma infections. Conversely, the emphasis on the management of crossbred cattle may offer fewer opportunities for pre-exposure to vectors and may result in limited or no immunity, thereby leading to a higher prevalence of the disease (Bock et al., 1997).

At herd level, herd type also emerged as a potential risk factor for bovine Anaplasma infections where cattle were raised for various purposes, viz., calf, dairy heifer, beef heifer, bull and dairy cow. Dairy cows had more than twice the odds of getting Anaplasma infection compared to calves, and between dairy heifers and beef heifers, dairy heifers were found to be more susceptible to Anaplasma infection while bull had lower odds than dairy cows. Calves are susceptible to anaplasmosis due to transplacental transmission of the disease and may acquire the infection from infected dams through vertical transmission or through exposure to ticks in calving areas or pastures (Radostits et al., 2000; Kocan et al., 2010; Aubry and Geale, 2011; Van Loo et al., 2023). The findings were consistent with the reports where A. marginale in dairy animals was higher than bulls and calves (Rajput et al., 2005). The greater prevalence of A. marginale in female cattle may be related to lactation in high-producing animals (Kocan et al., 2010) and probably because they are kept longer for breeding and milk production, with diets insufficient to meet their high demands. Additionally, the frequent use of contaminated needles to inject medications for milk let-down may contribute to the increased occurrence of tick-borne diseases in dairy animals. Another report suggested that exposure to A. marginale is common in dairy herds (Oliveira et al., 2011).

Size of herds has been reported as a risk factor for anaplasmosis (Okafor et al., 2019; Spare et al., 2020). In our study, herd sizes of >28 and 4–28 had higher odds compared to herd sizes of <4, and the findings were consistent with the previous reports (Okafor et al., 2019; Spare et al., 2020). However, another explanation might be the study design in which more cattle were tested in larger herds, which increases the herd-level sensitivity in larger herds. In conclusion, a substantial proportion of cattle and herds tested positive for Anaplasma infection, with herd size and type, age of individuals, sex and breed status significantly associated with the infection in cattle of these selected districts in Bangladesh. The study further suggests that regular health examinations for Anaplasma infection in larger herds, especially targeting older cattle, should be done within the context of Bangladesh.

Acknowledgements

The authors acknowledge the support of the Livestock and Dairy Development Project (LDDP), Department of Livestock Services (DLS), Ministry of Fisheries and Livestock, Govt. of Bangladesh and the owners of the commercial cattle farmers. The abstract was presented in the 29th international conference of WAAVP 2023, Chennai, India during 20–24 August 2023. M. M. R. Z. had been awarded travel grant from Dublin Scholarship fund.

Data availability statement

The data will be available.

Author contributions

M. M. R. Z. and N. A.: review of literature, investigation, resources, methodology, formal analysis, original draft preparation, writing – review and editing. M. A., M. A. H. M., M. M. R. S., M. R. R. R. and M. K. R.: methodology, investigation, formal analysis, writing – review and editing. B. C. R.: co-supervision, resources, methodology, formal analysis, writing – review and editing. M. H. T.: conceptualization, methodology, project administration, supervision, validation, visualization, investigation, resources, writing – review and editing. M. M. R. Z. and N. A. contributed equally to this work.

Financial support

The authors acknowledge the financial support (to principal investigator, M. H. T.; research and innovation subproject; project code: RP-C-03-24) of Livestock and Dairy Development Project (LDDP), jointly funded by the World Bank and Department of Livestock Services (DLS), Ministry of Fisheries and Livestock, Govt. of Bangladesh.

Competing interests

None.

Ethical approval

The study was approved by the Animal Welfare and Experimentation Ethical Committee (AWEEC) of Bangladesh Agricultural University (AWEEC/BAU/2022/12). Both written and oral consent were obtained from the owner/manager of the dairy cattle farm before collecting blood samples and data.

References

  1. Akter S, Paul S, Syed SUA, Mandal P and Nazneen S (2018) Prevalence and determinants of bovine anaplasmosis in Sylhet district of Bangladesh. International Journal of Natural Sciences 8, 01–06. [Google Scholar]
  2. Alim MA, Das S, Roy K, Masuduzzaman, Sikder MS, Hassan MM, Siddiki AZ and Hossain MA (2012) Prevalence of hemoprotozoan diseases in cattle population of Chittagong Division, Bangladesh. Pakistan Veterinary Journal 32, 221–224. [Google Scholar]
  3. Ananda KJ, D'souza PE and Puttalakshmamma GC (2009) Prevalence of haemoprotozoan diseases in crossbred cattle in Bangalore North. Veterinary World 2, 15–16. [Google Scholar]
  4. Atif FA, Khan MS, Iqbal HJ, Arshad GM, Ashraf E and Ullah S (2012) Prevalence of Anaplasma marginale, Babesia bigemina and Theileria annulata infections among cattle in Sargodha District, Pakistan. African Journal of Agricultural Research 7, 3302–3307. doi: 10.5897/AJAR11.2051 [DOI] [Google Scholar]
  5. Aubry P and Geale D (2011) A review of bovine anaplasmosis. Transboundary and Emerging Diseases 58, 1–30. doi: 10.1111/j.1865-1682.2010.01173.x [DOI] [PubMed] [Google Scholar]
  6. Bock R, Vos AD, Kingston T and McLellan D (1997) Effect of breed of cattle on innate resistance to infection with Babesia bovis, B. bigemina and Anaplasma marginale. Australian Veterinary Journal 75, 337–340. [DOI] [PubMed] [Google Scholar]
  7. Chowdhury S, Hossain MA, Barua SR and Islam S (2006) Occurrence of common blood parasites of cattle in Sirajgonj sadar area of Bangladesh. Bangladesh Journal of Veterinary Medicine 4, 143–145. [Google Scholar]
  8. Cochran WG (1977) Sampling Techniques, 3rd Edn, New York: John Wiley & Sons. [Google Scholar]
  9. Constable P, Hinchcliff K, Done S and Grunberg W (2017) Diseases of the haemolymphatic and immune systems. In Cathy Patterson, DVM (Ed.), Veterinary Medicine: A Textbook of the Diseases of Cattle, Horses, Sheep, Pigs, and Goats, 11th Edn. London, UK: Saunders Limited, pp. 716–844. [Google Scholar]
  10. de Echaide, ST, Knowles, DP, McGuire, TC, Palmer, GH, Suarez, CE and McElwain, TF (2001) Detection of cattle naturally infected with Anaplasma marginale in a region of endemicity by nested PCR and a competitive enzyme-linked immunosorbent assay using recombinant major surface protein 5. Journal of Clinical Microbiology 39, 1207–1207. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Farooqi SH, Ijaz M, Rashid MI, Nabi H, Islam S, Aqib AI, Hussain K, Khan A, Rizvi SNB, Mahmood S and Mehmood K (2018) Molecular epidemiology of bovine anaplasmosis in Khyber Pakhtunkhwa, Pakistan. Tropical Animal Health and Production 50, 1591–1598. [DOI] [PubMed] [Google Scholar]
  12. Futse JE, Ueti MW, Knowles Jr, DP and Palmer GH (2003) Transmission of Anaplasma marginale by Boophilus microplus: retention of vector competence in the absence of vector-pathogen interaction. Journal of Clinical Microbiology 41, 3829–3834. doi: 10.1128/jcm.41.8.3829-3834.2003 [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Hairgrove TB, Craig TM, Budke CM, Rodgers SJ and Gill RJ (2014) Seroprevalence of Anaplasma marginale in Texas cattle. Preventive Veterinary Medicine 116, 188–192. [DOI] [PubMed] [Google Scholar]
  14. Hassan MZ, Giasuddin M, Rahman MM, Ershaduzzaman M and Hasan M (2019) Identification of vector-borne blood protozoa in cattle and sheep in Bangladesh. Journal of Virology & Antivirals 2, 004. [Google Scholar]
  15. Hove P, Khumalo ZT, Chaisi ME, Oosthuizen MC, Brayton KA and Collins NE (2018) Detection and characterisation of Anaplasma marginale and A. centrale in South Africa. Veterinary Sciences 5, 26. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Huque K and Khan MYA (2017) Socio-geographic distribution of livestock and poultry in Bangladesh – a review. Bangladesh Journal of Animal Science 46, 65–81. [Google Scholar]
  17. Islam MS, Rahman MS, Hossain MZ and Haque MA (2019) Emerging status of anaplasmosis in cattle in Sirajganj district with therapeutic evaluation of traditional treatments. Asian-Australasian Journal of Bioscience and Biotechnology 4, 162–168. [Google Scholar]
  18. Islam SKS, Rumi TB, Kabir SML, Van der Zanden AGM, Kapur V, Rahman A, Ward MP, Bakker D, Ross AG and Rahim Z (2020) Bovine tuberculosis prevalence and risk factors in selected districts of Bangladesh. PLoS ONE 15, e0241717. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Khan NU, Sarwar MS, Ayaz S, Ali H, Ali A, Khan MA, Khan AU, Hussain M and Ali H (2019) Prevalence and risk factors analysis associated with anaplasmosis in symptomatic cattle under field conditions in southern Khyber Pakhtoonkhwa, Pakistan. Pure and Applied Biology 8, 2119–2127. doi: 10.19045/bspab.2019.80156 [DOI] [Google Scholar]
  20. Kocan KM, de la Fuente J, Blouin EF, Coetzee JF and Ewing S (2010) The natural history of Anaplasma marginale. Veterinary Parasitology 167, 95–107. [DOI] [PubMed] [Google Scholar]
  21. Kocan KM, de la Fuente J and Cabezas-Cruz A (2015) The genus Anaplasma: new challenges after reorganization. In Revue Scientifigue et Technique (International Office of Epizootics) 34, 577–586. [DOI] [PubMed] [Google Scholar]
  22. Mannan A, Alim MA, Manik M, Mahbub K, Rahman U and Alamgir HM (2022) Prevalence of anaplasmosis in cattle from Chattogram Division of Bangladesh. Bangladesh Journal of Veterinary and Animal Sciences 9, 67–73. [Google Scholar]
  23. Mohanta UK, Chikufenji B, Galon EM, Ji S, Ma Z, El-Sayed SAES, Amer MM, Do TT and Xuan X (2023) Molecular characterization and phylogeny of Anaplasma marginale, A. phagocytophilum and A. bovis in livestock of Bangladesh. Parasitology International 97, 102790. doi: 10.1016/j.parint.2023.102790 [DOI] [PubMed] [Google Scholar]
  24. Nazar M, Khan MA, Shah AA, Rahman SU, Khan I, Ullah A, Khan IU and Shuaib M (2018) Occurrence and transplacental transmission of Anaplasma marginale in dairy cattle. Slovenian Veterinary Research 55, 183–191. doi: 10.26873/SVR-499-2018 [DOI] [Google Scholar]
  25. Okafor CC, Collins SL, Daniel JA, Harvey B, Sun X, Coetzee JF and Whitlock BK (2018) Factors associated with seroprevalence of Anaplasma marginale in Kentucky cattle. Veterinary Parasitology: Regional Studies and Reports 13, 212–219. doi: 10.1016/j.vprsr.2018.07.003 [DOI] [PubMed] [Google Scholar]
  26. Okafor CC, Collins SL, Daniel JA, Coetzee JF and Whitlock BK (2019) Seroprevalence of bovine anaplasmosis in Georgia. Veterinary Parasitology: Regional Studies and Reports 15, 100258. [DOI] [PubMed] [Google Scholar]
  27. Oliveira JB, Montoya J, Romero JJ, Urbina A, Soto-Barrientos N, Melo ESP, Ramos CAN and Araújo FR (2011) Epidemiology of bovine anaplasmosis in dairy herds from Costa Rica. Veterinary Parasitology 177, 359–365. [DOI] [PubMed] [Google Scholar]
  28. Palmer GH, Brown WC and Rurangirwa FR (2000) Antigenic variation in the persistence and transmission of the Ehrlichia Anaplasma marginale. Microbes and Infection 2, 167–176. [DOI] [PubMed] [Google Scholar]
  29. Paramanandham K, Mohankumar A, Suresh KP, Jacob SS and Roy P (2019) Prevalence of Anaplasma species in India and the World in dairy animals: a systematic review and meta-analysis. Research in Veterinary Science 123, 159–170. [DOI] [PubMed] [Google Scholar]
  30. Parvizi O, El-Adawy H, Melzer F, Roesler U, Neubauer H and Mertens-Scholz K (2020) Seroprevalence and molecular detection of bovine anaplasmosis in Egypt. Pathogens 9, 64. [DOI] [PMC free article] [PubMed] [Google Scholar]
  31. Radostits OM and Done SH (2007) Veterinary Medicine: A Textbook of the Diseases of Cattle, Sheep, Pigs, Goats, and Horses, 10th Edn. New York: Elsevier Saunders, xxii, p. 2156. [Google Scholar]
  32. Radostits OM, Blood DC and Gay CC (2000) Veterinary Medicine: A Text Book of Disease of Cattle, Sheep, Pigs, Goats and Horse. 9th Edn. London: Baillere Tindall Publication, pp. 1172–1173, 1289–1290. [Google Scholar]
  33. Rahman ASMS, Sumon SMMR, Khan MAHNA and Islam MT (2015) Current status of subclinical form of babesiosis and anaplasmosis in cattle at Rangpur district in Bangladesh. Progressive Agriculture 26, 51–59. [Google Scholar]
  34. Rahman AKMA, Islam SKS, Talukder MH, Hassan MK, Dhand NK and Ward MP (2017) Fascioliasis risk factors and space-time clusters in domestic ruminants in Bangladesh. Parasites & Vectors 10, 228. [DOI] [PMC free article] [PubMed] [Google Scholar]
  35. Rajput ZI, Song-hua HU, Arijo AG, Habib M and Khalid M (2005) Comparative study of Anaplasma parasites in tick carrying buffaloes and cattle. Journal of Zhejiang University-Science B 6, 1057–1062. [DOI] [PMC free article] [PubMed] [Google Scholar]
  36. Rodríguez SD, Ortiz MÁG, Ocampo RJ and Murguía YCAV (2009) Molecular epidemiology of bovine anaplasmosis with a particular focus in Mexico. Infection, Genetics and Evolution 9, 1092–1101. [DOI] [PubMed] [Google Scholar]
  37. Roy B, Krücken J, Ahmed J, Majumder S, Baumann M, Clausen PH and Nijhof A (2018) Molecular identification of tick-borne pathogens infecting cattle in Mymensingh district of Bangladesh reveals emerging species of Anaplasma and Babesia. Transboundary and Emerging Diseases 65, e231–e242. [DOI] [PubMed] [Google Scholar]
  38. Samad MA, Bashar SA, Shahidullah M and Ahmed MU (1989) Prevalence of haemoprotozoan parasites in cattle of Bangladesh. Indian Journal of Veterinary Medicine 13, 50–51. [Google Scholar]
  39. Sarangi LN, Rana SK, Prasad A, Ponnanna NM and Sharma GK (2021) Prevalence of antibodies to Anaplasma in cattle and buffaloes of different organized herds in India. Journal of Parasitological Disease 45, 359–365. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Sharma DK, Bhatnagar CS, Bhardawaj B and Meena SK (2015) Incidence of haemoprotozoan diseases in cattle in Southern Rajasthan, India. International Journal of Current Microbiology and Applied Sciences 4, 509–514. [Google Scholar]
  41. Shoaib M, Rashid MI, Akbar H, Sheikh AA, Farooqi SH, Khan MA, Khan FA and Khan R (2021) Prevalence and molecular characterization of Anaplasma marginale in cattle population of Khyber Pakhtunkhwa Province, Pakistan. International Journal of Agriculture & Biologyissn 2021, 1560–8530. [Google Scholar]
  42. Siddiki AZ, Uddin MB, Hasan MB, Hossain MF, Rahman MM, Das BC, Sarker MS and Hossain MA (2010) Coproscopic and haematological approaches to determine the prevalence of helminthiasis and protozoan diseases of Red Chittagong Cattle (RCC) breed in Bangladesh. Pakistan Veterinary Journal 30, 1–6. [Google Scholar]
  43. Spare MR, Hanzlicek GA, Wootten KL, Anderson GA, Thomson DU, Sanderson MW, Ganta RR, Reif KE and Raghavan RK (2020) Bovine anaplasmosis herd prevalence and management practices as risk-factors associated with herd disease status. Veterinary Parasitology 277, 10021. [DOI] [PubMed] [Google Scholar]
  44. Talukder MH and Karim J (2001) Subclinical Anaplasma infection in crossbred cattle in Bangladesh. Bangladesh Veterinary Journal 35, 159–160. [Google Scholar]
  45. Van Loo H, Pascottini OB, Hooyberghs J, De Bleecker K, Ribbens S, Opsomer G and Pardon B (2023) Detection of Anaplasma phagocytophilum in fetal and placental tissue of bovine abortions and perinatal mortalities. Veterinary Record 193, e2880. [DOI] [PubMed] [Google Scholar]
  46. Watthanadirek A, Chawengkirttikul R, Poolsawat N, Junsiri W, Boonmekam D, Reamtong O and Anuracpreeda P (2019) Recombinant expression and characterization of major surface protein 4 from Anaplasma marginale. Acta Tropica 197, 105047. [DOI] [PubMed] [Google Scholar]
  47. World Bank (2018) Combined project information documents/integrated safeguards datasheet (PID/ISDS). Livestock development-based dairy revolution and meat production project (P161246).
  48. Ybañez AP and Inokuma H (2016) Anaplasma species of veterinary importance in Japan. Veterinary World 9, 1190–1196. doi: 10.14202/vetworld.2016.1190-1196 [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Data Availability Statement

The data will be available.

Articles from Parasitology are provided here courtesy of Cambridge University Press

RESOURCES