Molecular identification of tick-borne pathogens infecting cattle in Mymensingh district of Bangladesh reveals emerging species of Anaplasma and Babesia.

Tick-borne diseases are considered a major hindrance to the health and productive performance of cattle in Bangladesh. To elucidate the epidemiology of tick-borne pathogens (TBPs) in local cattle, a cross-sectional study was performed in the 12 subdistricts (Upazilas) of Mymensingh district in Bangladesh. Blood samples and ticks were collected from 384 clinically healthy cattle kept by 135 farmers from 96 randomly selected villages. DNA extracted from the blood samples was subsequently screened by polymerase chain reaction (PCR) and a Reverse Line Blot (RLB) hybridization assay using an in-house prepared chemiluminescence solution for the presence of Anaplasma, Ehrlichia, Rickettsia, Babesia and Theileria spp. A total of 2,287 ticks were collected from 232 infested cattle (60.4%, 232/384) and identified morphologically as Rhipicephalus (Boophilus) microplus (n = 1,432, 62.6%) and Haemaphysalis bispinosa (n = 855; 37.4%). The RLB results demonstrated that the majority of the cattle (62.2%) were infected with at least one TBP. Theileria orientalis infections were most common (212/384, 55.2%) followed by infections with Anaplasma bovis (137/384, 35.67%), Anaplasma marginale (16/384, 4.17%), Babesia bigemina (4/384, 1.04%) and Babesia bovis (2/384, 0.52%). A previously uncharacterized Anaplasma sp. (Anaplasma sp. Mymensingh) and Babesia sp. (Babesia sp. Mymensingh), which are genetically closely related to Anaplasma platys and B. bigemina, were detected in 50 of 384 (13.0%) and 1 of 384 (0.3%) of the blood samples, respectively. Key risk factors for the occurrence of T. orientalis, A. marginale and Anaplasma sp. Mymensingh were identified. In conclusion, this study revealed that cattle in Mymensingh district are mainly infested with R. microplus and H. bispinosa ticks and may carry multiple TBPs. In addition, two previously uncharacterized pathogens were detected in the bovine blood samples. The pathogenicity of these species remains to be determined.

Indigenous knowledge of pastoralists on respiratory diseases of camels in northern Kenya.

The camel disease terminology of pastoralists in northern Kenya differentiates between two respiratory disease complexes of camels. Participatory epidemiology data were collected in 2011 in three camel keeping communities (Gabra, Garri, and Somali) and analysed to assess the validity of this differentiation. Further queries assessed recurrence of the disease in the same animal, most affected age group, relative frequency of occurrence, morbidity rates, mortality rates and response to antibiotic treatment. Based on matrix scoring the cardinal symptom nasal discharge was significantly correlated with Respiratory Disease Complex 1 (RDC1; Somali Hergeb, Gabra & Garri Furri) while cough was correlated with Respiratory Disease Complex 2 (RDC2; Somali Dhuguta, Gabra Qufa, Garri Dhugud). RDC1 appears to occur regularly every year and does not respond to antibiotic treatments while outbreaks of RDC2 are only observed at intervals of several years and treated cases do generally respond to antibiotics. While RDC1 is more severe in calves, RDC 2 is mostly associated with respiratory disease in adults. Elements of this differentiation appear to be in agreement with other authors who differentiate between camel influenza (PI3 virus) and bacterial camel pneumonia, respectively.

Laboratory evaluation of efficacy and persistence of a 1% w/w fipronil pour-on formulation (Topline®) against Glossina palpalis gambiensis, Diptera: Glossinidae.

One zebu bull of 365 kg live weight was treated along the back line with 36 mL of fipronil as a pour-on formulation. Long-lasting mortalities of Glossina palpalis gambiensis were recorded despite exposure to sunlight and regular rinsing with 50 L of water during the following 5 months. Significantly higher mortalities were still observed even 140, 170 and 190 days after treatment following their triple releases or triple feeding of caged tsetse on the treated bull. Mortalities of 70, 80 and 44%, respectively, were recorded after 15 days of observation. This contrasted with the mortalities of control flies that were released in the presence of the untreated bull or fed in cages on the animal, amounting to 20 and twice 10% after 170 and 190 days. The feeding successes of the released or caged flies were higher than 95% and did not differ between control and experimental groups, indicating no repulsive or irritant effects of fipronil. The findings of this study are discussed, particularly in view of the potential of fipronil as an effective means for tsetse control.

Loads and antimicrobial resistance of Campylobacter spp. on fresh chicken meat in Nueva Ecija, Philippines.

This study was performed to determine the prevalence and to semiquantify Campylobacter spp. on chicken meat samples at 4 selected local wet markets in Nueva Ecija, Philippines, and to determine the antimicrobial resistance patterns of the Campylobacter isolates. Out of 120 chicken meat samples, 57 (47.5%) were Campylobacter spp. positive. The majority of isolated Campylobacter strains were identified as Campylobacter coli (54.4%) and 45.6% as Campylobacter jejuni. Most of these positive samples (52.6%) showed a very high quantitative Campylobacter contamination (most probable number > 2,400/g, lower confidence limit 580/g). For antimicrobial resistance testing, 44 C. coli/jejuni isolates were tested using the agar disk diffusion method. Out of these, 77.3% were resistant to ampicillin, followed by ciprofloxacin (70.4%), tetracycline (54.6%), erythromycin (20.2%), and gentamicin (11.4%). Of the isolates, 36.4% (n = 16) were resistant to 1 antimicrobial agent, 34.1% (n = 15) were resistance to 3 antimicrobial agents, 13.6% (n = 6) to 2 antimicrobial agents, 9.1% (n = 4) to 4 antimicrobial agents, and 6.8% (n = 3) to all 5 antimicrobial agents tested. Our data demonstrate a high contamination of fresh chicken meat with Campylobacter spp. at retail in the Philippines. The detected high Campylobacter prevalences and quantitative loads on chicken meat at retail in the Philippines highlight the need to implement efficient intervention measures along the food chain and to encourage sanitary handling of poultry meat.

A cross-sectional study of Salmonella in pre-slaughter pigs in a production compartment of northern Thailand.

A cross-sectional study was conducted to determine the prevalence of Salmonella and to associate management factors in fattening pigs in a production compartment of northern Thailand. A total of 194 fecal samples and 166 environmental samples were collected from 22 fattening pig herds for isolation and identification of Salmonella. An additional 427 serum samples were collected from the same herds to determine Salmonella antibodies using ELISA. A questionnaire was used to collect management factors likely to be associated with Salmonella identification. Prevalence of Salmonella in each sample and its confidence interval was adjusted for clustering by herds using linearization technique. A generalized estimating equation was used to determine the odds ratio and significance level for each management factor in a logistic regression model. Salmonella was found in all 22 study pig herds with a fecal sample prevalence of 63% (95%CI: 56-69%) and a serum sample prevalence of 72%. However, isolation results were not significantly different from ELISA results. The most isolated serotype was Salmonella Rissen (49%) followed by Salmonella Typhimurium (19%), Salmonella Stanley (12%) and Salmonella Weltevreden (4%) being significantly different in the different specimens collected (p=.024). The final logistic regression model with isolation results as outcome showed that medium herd size (OR=2.32, p=0.003), quality certification according to the Department of Livestock Development standard (OR=1.88, p=0.000), use of effective microorganisms (OR=1.51, p=0.022), slurry waste management (OR=2.17, p=0.000) and less number of pigs per pen (OR=1.12, p=0.000) were significantly associated with positive Salmonella isolation; with positive ELISA results, however, only the use of effective microorganisms was significantly associated (OR=2.63, p=0.011).

Seroprevalence of Trichinella in slaughter pigs in Kathmandu Valley, Nepal.

The aim of the present study was to determine the Trichinella seroprevalence in slaughter pigs in Kathmandu Valley, Nepal. Serum samples were obtained from 400 pigs at 4 major slaughterhouses and tested for Trichinella antibodies by ELISA using larval excretory-secretory (E/S) antigen. Four were positive and one was equivocal, giving a Trichinella seroprevalence of 1% (95% CI: 0.27 - 2.54). On titration, all positive and equivocal samples had titers greater than 1:80. Upon re-examination the equivocal sample failed to give a positive ELISA result. The pigs were from four major areas of Nepal, Kathmandu Valley, eastern Nepal, Terai and adjoining areas of the valley. Positive results were found from only Kathmandu Valley and adjoining areas. There was no significant difference in the prevalence between areas (p = 0.43). All four positive samples were from indoor managed pigs. The Trichinella seroprevalence determined in this study deserves a direct demonstration of the parasites for proof of the presence of Trichinella in Nepal and to discover the species and infection sources.

Reduced milk production in udder quarters with subclinical mastitis and associated economic losses in crossbred dairy cows in Ethiopia.

The objective of the study was to estimate the losses associated with subclinical mastitis (SCM) in crossbred dairy cows in the Central Highlands of Ethiopia. A split udder investigation was performed with 30 cows to determine production losses associated with SCM. Each quarter of the study cows was examined using the California Mastitis Test (CMT) and quarter milk production was measured over a period of 8 days. Production losses were determined for different CMT scores by comparing production of quarters with CMT score 0 to quarters with CMT scores trace, 1, 2 and 3, respectively. Using data from a recently published study, economic losses were determined for different farm sizes and production subsystems by multiplying the prevalence of the respective CMT scores with the production losses associated with these CMT scores. Mean quarter milk production was 0.82 +/- 0.40 kg per milking in the split udder trial. Milk production was reduced by 1.2%, 6.3%, and 33% in quarters with CMT scores 1+, 2+, and 3+, respectively. Using data from the published study, a quarter with SCM lost an average of 17.2% of its milk production. Production losses associated with SCM were estimated at 5.6% for the Addis Ababa Milk Shed. Stratified losses were highest (9.3%) in urban dairy farms (UDF) and small-scale farms (6.3%). The estimates of the financial losses ranged from US dollars 29.1 in dairy herds in secondary towns (DHIST) to US dollars 66.6 in UDF. A total loss of US dollars 38 was estimated for each cow per lactation. Reducing mastitis in UDF (highest prevalence) to the level of DHIST (lowest prevalence) could reduce the loss by US dollars 35. As this does not include costs associated with treatment or culling of diseased cows, this figure probably underestimates the possible benefits of control measures.

Risk factors for dairy cow mastitis in the central highlands of Ethiopia.

This study, with the objective of assessing the effect of risk factors on dairy cow mastitis in the central highlands of Ethiopia, was undertaken between February and September 2001 in the urban and peri-urban areas of Addis Ababa, Ethiopia. A prevalence study and questionnaire survey were carried out simultaneously. Clinical examination of lactating udders and California mastitis test (CMT) determined clinical and subclinical mastitis, respectively. Risk factors for subclinical and clinical mastitis were identified from data on animals and farm management by chi-square analysis and subsequent logistic regression. Cows aged at least 8 years, with poor body condition, with at least 8 parities and in at least the eighth month of lactation had a significantly higher risk for subclinical mastitis (p < 0.05). The risk was reduced for cows up to their third parity in good body condition and for cows receiving dry cow therapy. Cows aged at least 4 years, or with at least 8 parities, cows in at least the fourth month of lactation, cows with poor body condition, leaking milk or previous udder infections had a significantly higher risk of clinical mastitis (p <0.05). The risk was reduced by the use of separate towels for udder cleaning and by drying off at the end of lactation. Most of the risk factors were in agreement with previous reports. However, stage of lactation and drying-off style were in contrast to others. Further research is needed to identify the interrelationship between production level, specific pathogens and management risk factors.

The inception and development of basic animal health systems: examples of German development co-operation.

About thirty years ago the financial, logistic and manpower resources of veterinary and animal production services in the developing world were stretched to the limit. Epizootic disease control was their main and often only field activity, which left livestock owners to manage their daily production and health problems alone. To meet their requirements, Veterinary Services in these countries came under increasing public and political pressure to modify and adjust their approaches. This gave rise to a series of workshops in Africa (e.g. Bujumbura in Burundi and Blantyre in Malawi) and South-East Asia (e.g. Singapore, and Khon Kaen in Thailand), most of which were organised and facilitated by the German Agency for Technical Co-operation (GTZ) in close collaboration with French and British development co-operation agencies and universities. These workshops stimulated discussion with the key stakeholders and, thus, were most beneficial in supporting the process of developing alternative approaches. This paper reports in particular on the outcomes of the regional workshops held in Bujumbura, Burundi, in 1984, Blantyre, Malawi, in 1985, Bangui, Central African Republic, in 1988, Khon Kaen, Thailand, in 1989, Schmitten, Germany, in 1991, and Mzuzu, Malawi, in 1996 and 2000. For more than two decades, concepts of community-based livestock services in general, and primary animal health activities (PAHAs) in particular, have been developed and established in various developing countries. Over the years the PAHA concept has proved to be effective and has shown that livestock-keeping communities clearly benefit from such programmes. In presenting key features from some prominent and successful project examples (GTZ-supported projects in Thailand, Malawi and Somalia) it can be demonstrated that such approaches are not static but rather dynamic, requiring open minded innovative partners on both sides. Over the last few years, the delivery of PAHA has become the domain of non-governmental organisations. The propagation and application of this approach in various developing countries with limited veterinary infrastructure is supporting a privatisation process within the existing governmental veterinary structures, thus, allowing veterinary departments more freedom to focus on their core functions.

Control of Taenia saginata by post-mortem examination of carcasses.

BACKGROUND: A study to curb transmission cycle of a zoonotic Taenia cestodiasis between humans and cattle is presented. OBJECTIVE: To evaluate the reliability of meat inspection procedure in detecting carcasses of cattle with T. saginata cysticercosis. METHODS: A total of 55 cattle divided into two groups of artificially (n=30) and naturally (n= 25) infested animals were utilized. Total dissection method was used as a gold standard of validity. RESULTS: Meat inspection insensitively revealed cysticerci in 12 carcasses in each group compared with 24 and 23 carcasses revealed by total dissection in natural and artificial infestations, respectively. Sites of oncosphere invasion showed great variations with the two groups of cattle. In the predilection sites, most cysticerci were found in the heart, Triceps brachii, tongue and head muscles in that order. However, non-predilection sites (neck and back, hind limbs, chest, pelvic and lumbar regions, lungs and liver) considerably harboured high numbers of cysticerci. Observations indicated that except for the dead, degenerate or calcified cysticerci a careless meat inspector will most likely miss out quite a number of viable cysticerci, which blend the pinkish-red colour of the meat and be passed on for human consumption, becoming the source of bovine cysticercosis. CONCLUSIONS: The results confirmed that in spite of the time and efforts taken by meat inspectors looking for cysticerci at specified predilection sites of carcasses, this method is insensitive and inaccurate. To effectively improve meat inspection procedures, there is need to increase the area and number of predilection sites observed during inspection and vary them according to the nature of the animals, their husbandry history and the target human population for consumption. In addition, other control approaches such as vaccination, chemotherapy and immunodiagnosis should be developed and implemented to complement meat inspection procedures.

Epidemiological assessment of rinderpest surveillance and control in Uganda between 1990 and 1998.

Based on passive and active data, we report on an epidemiological assessment of surveillance and control of rinderpest (RP) in Uganda between 1990 and 1998. Active data were collected by administration of questionnaires to animal health personnel and their auxiliaries and to stockowners in six selected districts of eastern and northeastern Uganda. Passive data were extracted from vaccination and seromonitoring reports, and from field and laboratory reports. RP events were classified as "confirmed outbreaks", "suspected outbreaks" and "rumours". The classification of 56% of the RP events as "suspected outbreaks" indicates the difficulty in investigating disease outbreaks in Uganda. Although vaccination coverage and seroprevalence were <85% (the recommended target), they nevertheless corresponded well-reflecting effective vaccination. However, because of the low seroprevalence, a sizable population of cattle in Uganda remained at risk of RP. The agreement between the local and national disease reporting systems was low-to-moderate (kappa=0.39); this indicates inefficiency in disease reporting. Risk factors for RP outbreaks were cattle raids and communal grazing. Based on overlaid thematic maps of seroprevalence, vaccination coverage and RP events, close spatial and temporal associations were observed between cattle raids, transhumance and outbreaks and rumours. The high-risk areas were in the eastern and northeastern parts of the country. The results of this study support a phase approach of following the OIE pathway.

[Quality assurance of data collection and data processing in epidemiologic study data]. / Qualitätssicherung bei der Erhebung und Aufarbeitung von epidemiologischen Studiendaten.

Quality assurance of the data generating processes in epidemiologic studies is a prerequisite for the internal validity of study results. This paper presents practical aspects of such a quality assurance system pertaining to the planning, data gathering, data entry and data processing phase of a study. It is concerned with data obtained in the framework of a project rather than with data accumulating continuously in private practices, research institutes or veterinary faculties. During the planning phase of a project, standard operating protocols should be developed that assure a reliable performance of observation, coding and data entry. The data base structure, consisting of tables, input validation rules and queries, should be predefined and well documented. A data safety concept will provide the necessary integrity, physical safety and availability of the data. The paper presents technical solutions to common data processing problems with emphasis on re-coding and relational data base facilities (Microsoft-ACCESS) using a hypothetical study on risk factors for mastitis.

Oral Newcastle disease vaccination trials in Ethiopia.

Vaccination experiments were carried out in Ethiopia to study the efficacy of the NDV-I(2) vaccine against challenge with an Ethiopian velogenic strain of NDV. In experiment A, which comprised 300 broiler chicks, the efficacy of the ocular/drinking water application of the HB1/La Sota vaccine was compared with the ocular/drinking water and the feed application of the NDV-I(2) vaccine on untreated barley and sorghum. The NDV-I(2) vaccine applied by eye-drop or drinking-water protected the chickens against challenge as efficiently as combined HB1/La Sota vaccination but untreated barley and sorghum were unsuitable vaccine carriers. The vaccine virus could not be recovered and chickens neither seroconverted nor were they protected. In experiment B, 120 broiler chicks were divided into 6 treatment groups. One group each received NDV-I(2) vaccine mixed with untreated barley or sorghum which was applied immediately, or 14h after mixing and standing at ambient temperature. The fifth group was vaccinated intraocularly and via the drinking water with the NDV-I(2) vaccine. The sixth group remained untreated. Experiment B confirmed the results of experiment A. In experiment C, 100 chicks were divided into 5 groups of 20 chickens each. One group each received the NDV-I(2) vaccine on parboiled barley or sorghum as vaccine carriers 0 and 6h after mixing. The last group remained untreated. Parboiled barley given 0 or 6 h and parboiled sorghum given 0 h after mixing with the vaccine led to seroconversion and protection of the chickens. Parboiled sorghum given 6h after mixing with the vaccine did not. It is concluded that the thermostable NDV-I(2) vaccine may be a suitable vaccine for oral application under Ethiopian conditions.

Genital myiasis (Wohlfahrtiosis) in camel herds of Mongolia.

Genital infestations caused by Wohlfahrtia magnifica (Schiner, 1862) has been reported as being a common problem encountered in female camels in the Gobi desert. Thus, a field investigation to establish the prevalence of wohlfarthiosis in camel herds in the eastern Gobi district was carried out between May and July 1994. The objectives of the study were to establish the relevance of genital myiasis, and to describe the disease patterns, clinical course and pathomorphological changes associated with it. The field study was designed to suit the specific ecological, infrastructural and logistic conditions. Two cross-sectional samples were taken from 45 selected herds in six different areas of the Chatanbulag Sumon to obtain data on herd structure, age distribution, and the breeding history of infested female animals. Post partum events and previous occurrence of genital myiasis were recorded by use of a standardised questionnaire. Clinically infested animals were first detected visually. All camels to be investigated further were subsequently immobilised using ropes and the genitals were examined for tissue lesions and the presence of larvae. Examination of 1676 Bactrian camels from 45 selected herds in six different areas of the Chatanbulag Sumon in the Eastern Gobi district, Mongolia, led to an estimate of Wohlfahrtia magnifica infestation rates between 8-10%. Most myiasis cases were found in older females (> 4 yr), younger animals were infested at a lower rate. Highest prevalence rates were discovered during June and July, highest levels of infestation occurred in the Aman Us Chudak region with infestation rates up to 15%.

Productivity and health of camels (Camelus dromedarius) in Somalia: associations with trypanosomosis and brucellosis.

In Somalia, one of the world's largest dromedary populations of about 5.3 million animals are kept by nomadic pastoralists under traditional management. Interest in the development potential of camel herds in the semi-arid areas of central Somalia initiated an investigation to determine the productivity of herds, their major diseases and likely associations among these parameters. Using a systems approach, data were collected for herd production parameters, environmental factors, management and production systems, and health variables. One thousand and thirty nine camels in 33 herds were studied in the central regions of Somalia. Trypanosoma evansi prevalence ranged from 1.7% in blood-smears to 56.4% using enzyme-linked immunosorbent micro-assay (microELISA). Seroprevalence for brucellosis was determined as 1.9% by the standard agglutination test (SAT) and 0.3% by the complement fixation test (CFT). Using multiple regression, 15% of the total variation of the general fertility rate was explained by the results of the microhaematocrit centrifugation technique (MHCT) and the microELISA for T. evansi, CFT results for brucellosis, herdsize, and young stock death rate. Among herd production variables, herd size differed significantly for different management units. Young stock death rates, as well as general fertility rates varied in the ecological subzones with a marked effect in the zones labeled "Inland". Various other associations were noted among demographic, husbandry and disease variables. The importance of trypanosomosis and brucellosis to the productivity of herds and measures to control their limiting effects on production were discussed.

Analyses of baseline survey data on rinderpest in Bahr el Ghazal Province, with proposal of an improved vaccination strategy against rinderpest for southern Sudan.

Results from analyses of baseline surveillance data on rinderpest are used for proposing an improved vaccination strategy against rinderpest in southern Sudan. Sera from 4,074 (47%) of the total sample of 8,565 cattle collected in a series of cross-sectional surveys in 400 cattle camps in the Bahr el Ghazal Province of southern Sudan were tested for rinderpest antibodies using the standard virus neutralisation test (VNT) technique: 77.4% were positive while 22.6% gave negative results. The data were cross-classified according to five variables: herd management, breed, age, sex and geographic region (grazing location). The percentage antibody-positivity level (taken as an approximation of past experience with rinderpest antigen and the corresponding prevalence ratio estimates of relative risk) for each variable are discussed within the context of the known characteristics of immunity to rinderpest in endemic areas and the husbandry practices of the cattle owners in the study area. Results suggest that rinderpest "hot-spots" of transmission and/or low level of herd immunity should be mapped out for concentrated efforts to vaccinate calves and young adults so that the high level of antibody-positivity observed in this study can be maintained and transmission permanently interrupted.