Epidemiological Investigation of Brucellosis, Toxoplasmosis and Coxiellosis Associated with Reproductive Disorders in Small Ruminants

Abstract

The present study was to evaluate the “Epidemiological Investigation of Brucellosis, Toxoplasmosis and Coxiellosis Associated with Reproductive Disorders in Small Ruminants” (SR) at Northern Barind Tract (NBT) in Bangladesh from January, 2012 to June, 2015. A total 2667 small ruminants were selected and recorded 270 (10.2%) reproductive disorder cases, also 475 blood samples were collected from those animals. The serum sample was then subjected for testing of Brucella and Toxoplasma. The common Brucella & Toxoplasma positive and abortion occurred during the time of study were about 91 serum samples plus aborted tissue (20) were tested for Coxiella by using ELISA & PCR. The whole research was divided into 4 Experiments to achieve the goals successfully. Experiment I: Retrospective study of reproductive diseases in small ruminants This study was to determine the pattern of reproductive diseases at NBT in Bangladesh. Records of 2667 clinical cases of small ruminants (2394 goats, 273 sheep) from questionnaires report under this study, during July 2012 to June 2013 were analyzed to assess the importance of existing diseases. The small ruminants were significantly (P<0.05) suffering from various diseases and disorders. The maximum 816 (30.6%) small ruminants were affected by infectious diseases, whereas, reproductive disease prevalence was 10.2%. The highest prevalence of diseases (89.8%) was observed in goat than in sheep (10.2%). The highest & lowest prevalence of reproductive disorders in relation to sex were 32.5% & 1.9% in anoestrus and posthitis. The age had significant effect (P<0.05) and highest value were 20.4%, 7.9% & 4.5% observed in anoestrus of young, adult and old ages, respectively. The season had significant effect (P<0.05) and the overall disease prevalence was higher in rainy season (40.4%), but the individual highest value observed in anoestrus 14.7% in winter season. Among the total diseases approximately, 10% reproductive diseases and disorders were recorded in SR. Moreover, the gout species, female animal, young age, rainy season were greater chance to attack RD, particularly an anoestrus problem of small ruminants at NBT in Bangladesh. Experiment-II: Investigation on Brucellosis associated with reproductive disorders in small ruminants A seroepidemiological study of Brucella infections was in small ruminants at NBT in Bangladesh and a cross-sectional multi-stage sampling technique was employed to select 475 small ruminants, 396 goats and 79 sheep from the target populations. Serum was collected from the animals, and serially tested using Rose Bengal Test and iELISA according to the protocol recommended by the manufacturer. The overall prevalence of brucellosis was 12.0%, 9.3%, and 2.7% in SR, goats and sheep, respectively. Brucellosis was insignificantly (P>0.05) highest positive reactors value in species, age, parity, flock size and location were 5.6%, 8.9% in older goat and sheep; 7.6%, 5.5% and 15.7% 1st parity in small ruminants, goat and sheep, 8.2% small flock of small ruminants; 5.9%, 1.5%, 2.3% and 2.3% into Rajshahi, Chapai Nawabgonj, Natore and Naogaon district at NBT in Bangladesh. The brucellosis was higher insignificant (P>0.05) negative correlation with Local breed (6.9%); heavy body weight (6.1%) and rainy seasons (6.1%) of small ruminants in study area. Brucellosis was positive and highly significant effect (P<0.01) of female animal (9.5%) but negative effect with traditional biosecurity (8.2%) and grazing (8%) in SR. The seropositive rate of Brucella was higher in non-pregnant (4%) than pregnant (4%) and aborted (2.1%) animals with reproductive disease concern at NBT in Bangladesh. Experiment-III: Assessment of Toxoplasmosis linked with reproductive disorders in small ruminants The 3rd experiment was carried out on 475 of SR serum samples were subjected to test for Toxoplasma anti-T. Gondii antibodies using kit for human Toxo test MT (Eiken Kagaku, Japan) according to the protocol recommended by the manufacturer. The overall seroprevalence of toxoplasmosis was 56%. The highest prevalence of toxoplasmosis was recorded in goat (45.7%), local breed (31.2%), female animal (34.3%), older age (26.1%), 1st parity (31.4%), medium body weight (23.7%), small size flock (38.7%), traditional biosecurity (30.9%), grazing habit (26.9%), summer season (20.0%), Rajshahi region (30.9%), non-pregnant (49.3%) in SR and abortion (10.7%) cases according to their influencing factors. The prevalence Toxoplasma gondii opportunity increased in female, Local breed, goat species, older age, smaller flock size, traditional biosecured farm, grazing habit, rainy season, aborted condition and Rajshahi distract (more urbanization area) at NBT in Bangladesh. Experiment-IV: Survey of Coxiellosis related to reproductive disorders in small ruminants The experiment-4 was designed to find out the other zoonotic diseases present in collected samples. For that, the positive Brucella, common Brucella and Toxoplasma positive and randomly selected (location wise) total 91 serum samples were send to National Reference Laboratory (NRL) in Germany to identify Coxiella in small ruminants. Serological test was performed by iELISA on goat and sheep database created with Microsoft Office software Excel 2007 (Microsoft®, Redmond) and SPSS program. An overall seroprevalence of Coxiella was found 11%. Goats was significantly (P<0.01) lower seroprevalence than sheep, respectively 5.6% and 30.0%. Small ruminants had significantly (P<0.05) higher chance of Coxiella in animals reared at smaller size flock (13.1%) and city adjacent to border (Rajshahi, Naogaon & Chapai Nawabjong) than their corresponding groups. The seropositivity was higher in Local breed (7.7%), female animals (7.7%), older age (6.6%), medium & heavy body weight (5.5%), traditional biosecurity (6.6%) and rainy season (7.7%) than others groups and had insignificant effect (P>0.01). The parity and pregnancy status of SR were negative correlation but significant effect (P<0.01) with Q fever infection in experimental area. The animals from the stall feeding (4.4%) had negative but insignificant (P>0.01) association and lower seroprevalence than animals from the grazing on field (6.6%). First report, the seroprevalence of Q fever in goat and sheep in Bangladesh is established now. Female Local breed from goat and sheep having lower body weight, older age, > 3rd parity, traditional biosecurity farms and grazing in field were more chance to Q fever attack.