Papers by A K M Anisur Rahman
Tropical Medicine and Health, 2016
Background: A Bayesian latent class evaluation was used to estimate the true prevalence of brucel... more Background: A Bayesian latent class evaluation was used to estimate the true prevalence of brucellosis in livestock farmers and patients with prolonged pyrexia (PP) and to validate three conditionally dependent serological tests: indirect ELISA (iELISA), Rose Bengal Test (RBT), and standard tube agglutination (STAT). A total of 335 sera from livestock farmers and 300 sera from PP patients were investigated. Results: The true prevalence of brucellosis in livestock farmers and PP patients was estimated to be 1.1 % (95 % credibility interval (CrI) 0.1-2.8) and 1.7 % (95 % CrI 0.2-4.1), respectively. Specificities of all tests investigated were higher than 97.8 % (95 % CrI 96.1-99.9). The sensitivities varied from 68.1 % (95 % CrI 54.5-80.7) to 80.6 % (95 % CrI 63.6-93.8). The negative predictive value of all the three tests in both populations was very high and more than 99. 5 % (95 % CrI 98.6-99.9). The positive predictive value (PPV) of all three tests varied from 27.9 % (95 % CrI 3.6-62.0) to 36.3 % (95 % CrI 5.6-70.5) in livestock farmers and 39.8 % (95 % CrI 6.0-75.2) to 42.7 % (95 % CrI 6.4-83.2) in patients with PP. The highest PPV were 36.3 % for iELISA and 42.7 % for RBT in livestock farmers and pyrexic patients, respectively. Conclusions: In such a low prevalence scenario, serology alone does not help in diagnosis and thereby therapeutic decision-making. Applying a second test with high specificity and/or testing patients having history of exposure with known risk factors and/or testing patients having some clinical signs and symptoms of brucellosis may increase the positive predictive value of the serologic tests.
Bangladesh Journal of Veterinary Medicine, 2014
A cross-sectional study was conducted to determine the prevalence of bovine cryptosporidiosis usi... more A cross-sectional study was conducted to determine the prevalence of bovine cryptosporidiosis using 110 fecal samples of crossbred diarrhoeic calves from two different areas (Muktagacha, Mymensingh and Shajadpur, Sirajgonj) in Bangladesh during April 2012 to September 2014. The fecal samples were screened by rapid detection kit and confirmed by Modified Ziehl- Neelsen staining, and polymerase chain reaction (PCR). The positive samples along with standard positive control yielded 1325bp band on PCR. The overall prevalence of cryptosporidiosis in crossbred calves was 28.18% (31/110) by rapid detection kit. The higher prevalence of cryptosporidiosis was found in the calves from Shajadpur (29.76%) than the calves from Muktagacha (23.08%).The prevalence of cryptosporidiosis was significantly (p<0.001) higher in calves between 1-2 months (70%) age group than less than one month age group (24.49%). Cryptosporidiosis was not observed in calves over two months age. The prevalence of crypt...
PLOS ONE, 2022
Bovine rotavirus (BRV) is considered the leading cause of calf diarrhea worldwide, including Bang... more Bovine rotavirus (BRV) is considered the leading cause of calf diarrhea worldwide, including Bangladesh. In this study we aimed to identify risk factors for BRV infection and determine the G and P genotypes of BRV strains in diarrheic calves. Fecal samples were collected from 200 diarrheic calves in three districts between January 2014 and October 2015. These samples were screened to detect the presence of BRV using rapid test-strips BIO K 152 (RTSBK). The RTSBK positive samples were further tested by polyacrylamide gel electrophoresis and the silver staining technique to detect rotavirus dsRNA. Risk factors were identified by multivariable logistic regression analysis. The G and P genotypes of BRV were determined by RT-PCR and sequencing. A phylogenetic tree was constructed based on the neighbor-joining method using CLC sequence viewer 8.0. About 23% of the diarrheic calves were BRV positive. The odds of BRV infection were 3.8- (95% confidence interval [95% CI]: 1.0–14.7) and 3.9-t...
Veterinary World
Background and Aim: Bovine tuberculosis (bTB) is an infectious disease of cattle, mainly caused b... more Background and Aim: Bovine tuberculosis (bTB) is an infectious disease of cattle, mainly caused by Mycobacterium bovis. This study aimed to evaluate the efficacy of the interferon-gamma (IFN-γ) assay and single-intradermal comparative tuberculin test (SICTT) in detecting bTB. Materials and Methods: In an earlier study, 150 positive, 83 inconclusive, and 480 negative animals from 24 cattle herds were screened using SICTT. From these groups, 125 positive, 17 inconclusive, and six negative animals were subsequently verified using the IFN-γ assay. Single-intradermal comparative tuberculin test outcomes were interpreted according to standard guidelines, whereas blood samples were collected and stimulated with purified protein derivatives. Sandwich enzyme-linked immunosorbent assay was used to measure secreted IFN-γ. Concordant and Bayesian latent class analyses were performed to evaluate test performance. Results: Results from the IFN-γ assay revealed that 83.2%, 64.7%, and 16.67% of the...
PLOS ONE, 2021
Bovine tuberculosis (bTb) is endemic in Bangladesh but the true prevalence has not yet been repor... more Bovine tuberculosis (bTb) is endemic in Bangladesh but the true prevalence has not yet been reported. Our objectives for this study were to determine the true prevalence and identify risk factors for bTb at the animal- and herd-level in Bangladesh. A total of 510 cows were randomly selected during January 2018 to December 2018. Caudal fold (CFT) and comparative cervical tuberculin tests (CCT) were serially interpreted. Animal- and herd-level risk factor data were collected using a pre-tested questionnaire. The hierarchical true prevalence of bTb was estimated within a Bayesian framework. The herd- and animal-level risk factors were identified using mixed effects logistic regression. The apparent prevalence of bTb was 20.6% [95% Confidence Interval (CI): 17.3; 24.3] based on CFT. The animal-level true prevalence of bTb was 21.9 (13.0; 32.4). The herd-level true prevalence in different regions varied from 41.9% to 88.8%. The region-level true prevalence was 49.9 (13.8; 91.2). There is...
BackgroundThe study was aimed to estimate the true prevalence of human tuberculosis (TB); identif... more BackgroundThe study was aimed to estimate the true prevalence of human tuberculosis (TB); identify risk factors and clinical symptoms of TB; and detect rifampicin (RIF) sensitivity in Bangladesh.MethodsThe cross-sectional study was conducted in three Bangladesh districts during 2018. Potential risk factors, clinical symptoms, and comorbidities were collected from 684 TB suspects. Sputum specimens were examined by LED microscopy. TB hierarchical true prevalence, risk factors and clinical symptoms were estimated and identified using a Bayesian analysis framework. Rifampicin sensitivity of M. tuberculosis (MTB) was detected by GeneXpert MTB/RIF assay.ResultsThe median TB true prevalence was 14.2% (3.8; 34.5). Although overall clustering of prevalence was not found, several DOTS centers were identified with high prevalence (22.3% to 43.7%). Risk factors for TB identified (odds ratio) were age (> 25 to 45 years 2.67 (1.09; 6.99), > 45 to 60 years 3.43 (1.38; 9.19) and individuals i...
PLOS ONE, 2020
A cross-sectional survey was conducted in selected districts of Bangladesh to estimate the preval... more A cross-sectional survey was conducted in selected districts of Bangladesh to estimate the prevalence of bovine tuberculosis (bTB), and to identify the risk factors for bTB. We included 1865 farmed cattle from 79 herds randomly selected from five districts. Herd and animal level data were collected using semi-structured interviews with cattle herd owners. The single intradermal comparative tuberculin test (SICTT) was used to estimate the prevalence of bTB. The risk factors were identified using mixed-effect multiple logistic regression analyses. The overall herd and animal level prevalences of bTB were estimated to be 45.6% (95% Confidence Interval [CI] = 34.3–57.2%) and 11.3 (95% CI = 9.9–12.8%), respectively, using the OIE recommended >4 mm cut-off. The true animal level prevalence of bTB was estimated to be 11.8 (95% Credible Interval = 2.1–20.3%). At the herd level, farm size, bTB history of the farm and type of husbandry were significantly associated with bTB status in univa...
Pathogens, 2020
Foot-and-mouth disease (FMD) is highly endemic in Bangladesh. Using passive surveillance data (ca... more Foot-and-mouth disease (FMD) is highly endemic in Bangladesh. Using passive surveillance data (case records from all 64 districts of Bangladesh, 2014–2017) and district domestic ruminant population estimates, we calculated FMD cumulative incidence per 10,000 animals at risk per district, conducted cluster (Moran’s spatial autocorrelation and scan statistics) and hotspot analysis (local indicator of spatial association statistic), created predictive maps and identified risk factors using a geographically weighted regression model. A total of 548,817 FMD cases in cattle and buffalo were reported during the four-year study period. The highest proportion (31.5%) of cases were reported during the post-monsoon season, and from Chattogram (29.2%) division. Five space-time clusters, 9 local clusters, and 14 hotspots were identified. Overall, higher cumulative incidences of FMD were consistently predicted in eastern parts of Bangladesh. The precipitation in the pre-monsoon season (p = 0.0008...
Transboundary and Emerging Diseases, 2017
Using a hospital-based case-control study design, our aim was to identify risk factors for-and sp... more Using a hospital-based case-control study design, our aim was to identify risk factors for-and space-time clusters of-Peste des Petits Ruminants (PPR) in Mymensingh, Bangladesh. Three hundred and eighty PPR cases diagnosed between January 2005
Bangladesh Journal of Veterinary Medicine, 2017
The importance of brucellosis is primarily due to its public health significance and economic los... more The importance of brucellosis is primarily due to its public health significance and economic loss for the animal industry. The present study was performed to determine the seroprevalence of brucellosis in man and animals. A total of 1,452 samples (cattle 913, buffaloes 99, sheep 40, goats 50 and persons 350) were collected from Central Cattle Breeding and Dairy Farms, Savar, Dhaka and 5 districts (Mymensingh, Jamalpur, Gaibandha, Rangpur and Bagerhat) of Bangladesh. All samples were screened by RBT and the RBT positive sera were re–tested with SAT CFT, ELISA and qRT-PCR. Out of 913 cattle and 99 buffalo sera, 48 cattle and 7 buffalo sera showed positive reaction to RBT i.e. prevalence of brucellosis is 5.3% in cattle and 7.1% in buffaloes. The 350 human sera and all sheep and goats samples were negative to RBT. Among the RBT positive sera, 12 sera were found to contain <em>Brucella </em>DNA by genus specific IS711 quantitative real time PCR (qRT-PCR); and all PCR positi...
Zoonoses and Public Health, 2017
SummaryTo determine the role of different Brucella (B.) spp. in Bangladesh, 62 animal samples and... more SummaryTo determine the role of different Brucella (B.) spp. in Bangladesh, 62 animal samples and 500 human sera were tested. Animal samples from cattle, goats and sheep (including milk, bull semen, vaginal swabs and placentas) were cultured for Brucella spp. Three test‐positive human sera and all animal samples were screened by Brucella genus‐specific real‐time PCR (RT‐PCR), and positive samples were then tested by IS711 RT‐PCR to detect B. abortus and B. melitensis DNA. Only B. abortus DNA was amplified from 13 human and six animal samples. This is the first report describing B. abortus as the aetiological agent of brucellosis in occupationally exposed humans in Bangladesh. Of note is failure to detect B. melitensis DNA, the species most often associated with human brucellosis worldwide. Further studies are required to explore the occurrence of Brucella melitensis in Bangladesh.
Tropical Animal Health and Production, 2016
A cross-sectional study was carried out to estimate the true prevalence of Brucella spp. and iden... more A cross-sectional study was carried out to estimate the true prevalence of Brucella spp. and identify allied risk factors/indicators associated with brucellosis in the Dinajpur and Mymensingh districts of Bangladesh. A total 320 stratified random blood samples were collected and tested in parallel for Brucella antibodies using Rose Bengal (RBT), slow agglutination (SAT), and indirect and competitive ELISA. In addition, a structured questionnaire was administered to each household herd owner to gather information regarding potential risk factors. Both univariate and multivariate logistic regression analyses were used to identify potential risk factors or indicators at animal level. A Bayesian approach was used to estimate the true prevalence of brucellosis along with the test performances (Se and Sp). The estimated animal level true prevalence in cattle was 9.70 % (95 % CPI 5.0-16 %) and in goat 6.3 % (95 % CPI 2.8-11.0 %). The highest sensitivity was achieved by SAT ranges from 69.6 to 78.9 %, and iELISA was found to be more specific (97.4 to 98.8 %) in comparison with other tests. On the other hand, a significant level of (P < 0.05) Brucella seropositivity was found in cattle that breed naturally compared with those that undergo artificial insemination. In goats, exotic breeds were significantly associated (P < 0.05) with Brucella seroprevalence compared with indigenous breeds. Goats with a previous records of abortion and/or retained placenta were also found to have significant levels (P < 0.05). Cows with previous abortion records showed higher odds (18 times) of being seropositive. None of the evaluated tests can be recommended to apply alone for the diagnosis of bovine and caprine brucellosis.
Veterinary World, 2013
Aim: To determine the extent of concurrent infection and seasonal distribution of gastrointestina... more Aim: To determine the extent of concurrent infection and seasonal distribution of gastrointestinal parasites in cross-bred cattle of Shahzadpur upazila of Sirajganj district, Bangladesh. Materials and Methods: Faecal samples from 4248 cross-bred cattle presented to the diagnostic centre of Milk Vita, Baghabari, Sirajganj with complains of digestive disturbances over the period from November, 2008 to October, 2009 were examined grossly with naked eye followed by microscopic examination with direct smear method, Will's floatation and sedimentation techniques. Results: Out of 4248 faecal samples examined, 3268 (76.93%) samples harboured one or more parasitic ova or cyst and the rest 980 (23.07%) samples found free of parasitic ova or cyst. Among the positive cases, single infection of fascioliasis (29.0.5%), paramphistomiasis (8.3%), toxocariasis (11.32%), haemonchosis (2.47%), monieziasis (0.7%), balantidiasis (4.19%), trichuriasis (1.1%), trichostrongylosis (1.4%) and strongyloidosis (1.6%) were diagnosed. Mixed infection with at least two (dual infection) and/ or any three of above mentioned parasitic species (triple infection) were also recorded. Cattle harbouring eggs of one parasite were more common [60.03% (95% Confidence interval (CI): 58.53, 61.51)] than those harbouring eggs of two [15.44% (95% CI, 14.36, 16.56)] or three [1.46% (95% CI, 1.12, 1.87)] parasites concurrently. Significantly (p<0.001) higher proportion of fascioliasis cases observed in rainy season compared to those in winter and summer season, similar trends were also noticed in case of paramphistomiasis, toxocariasis and balantidiasis. An increasing trend of occurrence from summer through rainy and winter season was observed in case of haemonchosis, monieziasis, trichuriasis and strongyloidosis but not statistically significant (p>0.05). A non-significant (p>0.005) decreasing trend of occurrence from winter through summer and rainy season was also observed in case of trichostrongylosis. Conclusion: The result of current study clearly indicate that helminth infections are highly prevalent in cross-bred cattle of the study area. The findings on abundance and distribution of gastrointestinal parasitism in different age groups of cattle, the polyparasitism nature of the disease and the seasonal variation of occurrence obtained from present study will therefore assist the clinicians for forecasting of parasitism and make awareness among the farmers to take appropriate control measures against them.
Journal of Nepal Agricultural Research Council, 2018
Buffalo is the most important livestock commodities for milk, meat production and several other m... more Buffalo is the most important livestock commodities for milk, meat production and several other multipurpose uses distributed densely from southern tarai to northern mid-hills in Nepal. Among several internal parasitic diseases fascioliasis is highly economic one caused by Fasciola in buffaloes. However, there are only few studies carried on prevalence of fascioliasis emphasizing buffaloes in relation to seasonal (summer and rainy, and winter) and altitudinal variations. Therefore, we examined prevalence of fascioliasis seasonally and vertically. For the purpose, we selected two districts of eastern Nepal and sampled from low altitude area known as Madhesha ranging from 175-200, Dhankuta from 800-1200 m, and Murtidhunga from 1800-2200 m elevation from the sea level, representing tarai, mid hills and high hills, respectively. Altogether from February 2013 to January 2014 at every two months interval we collected 798 fecal samples from buffaloes; 282 from Murtidhunga, 239 from Dhankut...
Parasites & Vectors, 2017
Background: A retrospective observational study was conducted to identify fascioliasis hotspots, ... more Background: A retrospective observational study was conducted to identify fascioliasis hotspots, clusters, potential risk factors and to map fascioliasis risk in domestic ruminants in Bangladesh. Cases of fascioliasis in cattle, buffalo, sheep and goats from all districts in Bangladesh between 2011 and 2013 were identified via secondary surveillance data from the Department of Livestock Services' Epidemiology Unit. From each case report, date of report, species affected and district data were extracted. The total number of domestic ruminants in each district was used to calculate fascioliasis cases per ten thousand animals at risk per district, and this was used for cluster and hotspot analysis. Clustering was assessed with Moran's spatial autocorrelation statistic, hotspots with the local indicator of spatial association (LISA) statistic and space-time clusters with the scan statistic (Poisson model). The association between district fascioliasis prevalence and climate (temperature, precipitation), elevation, land cover and water bodies was investigated using a spatial regression model. Results: A total of 1,723,971 cases of fascioliasis were reported in the three-year study period in cattle (1,164,560), goats (424,314), buffalo (88,924) and sheep (46,173). A total of nine hotspots were identified; one of these persisted in each of the three years. Only two local clusters were found. Five space-time clusters located within 22 districts were also identified. Annual risk maps of fascioliasis cases correlated with the hotspots and clusters detected. Cultivated and managed (P < 0.001) and artificial surface (P = 0.04) land cover areas, and elevation (P = 0.003) were positively and negatively associated with fascioliasis in Bangladesh, respectively. Conclusions: Results indicate that due to land use characteristics some areas of Bangladesh are at greater risk of fascioliasis. The potential risk factors, hot spots and clusters identified in this study can be used to guide science-based treatment and control decisions for fascioliasis in Bangladesh and in other similar geo-climatic zones throughout the world.
Amaç: Mevcut araştırmanın amacı buzağı ölümleri ile ilgili faktörlerin araştırılması amacı ile ya... more Amaç: Mevcut araştırmanın amacı buzağı ölümleri ile ilgili faktörlerin araştırılması amacı ile yapıldı.
Background Brucellosis is an ancient and one of the world’s most widespread zoonotic diseases aff... more Background Brucellosis is an ancient and one of the world’s most widespread zoonotic diseases affecting both, public health and animal production. It is endemic in many developing countries of Asia, Africa and Latin America including Bangladesh. Since the first report in 1970, a lot of brucellosis seroprevalence reports are available in cattle, goats, sheep and humans in Bangladesh. Most of the previously reported prevalence studies were based on non-random samples, which may not give a true representation of the status of the disease in respective populations. Some authors also investigated the risk factors in cattle. The tests used for the diagnosis of brucellosis in domestic ruminants and humans are imperfect and their performance was not evaluated in Bangladesh. The true prevalence of brucellosis in domestic ruminants is not known and is essential for analyzing the impact of this disease in domestic ruminants in Bangladesh. Indeed, when diagnostic tests are used without evaluati...
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Papers by A K M Anisur Rahman