Evaluation of foot and mouth vaccination for yak (<Emphasis Type="Italic">Bos grunniens</Emphasis>) in Pakistan

In northern Pakistan, many farming communities rely on domestic yak (Bos grunniens) as a principle source of income. A 2006 participatory disease surveillance report from this region indicated that foot-and-mouth disease (FMD) is the most prevalent annual disease of yak. Our objectives of this study were to determine exposure levels of yak to FMD virus; implement a vaccination program based on current, regional FMD virus serotypes and subtypes; and quantify immune responses following vaccination. Blood samples were used to determine pre-vaccination exposure of animals to FMD virus by antibody presence to non-structural proteins of FMD virus using a 3-ABC trapping indirect ELISA. Vaccine used consisted of FMD serotypes ‘O’ (PanAsia-2), ‘A’ (Iran-05), and ‘Asia-1’ (Shamir), but changed later during the study to match newly circulating viruses in the country (‘O’-PanAsia-2; ‘A’-Turk-06 and Asia-1-Sindh-08). Three hundred sixty-three blood samples were tested from selected villages to determine pre-vaccination FMD virus exposure in yak with an average of 37.7%. Immune responses from initial vaccination and booster dose 30 days later showed clear protective levels (as mean percent inhibition) of antibodies against structural proteins of serotypes ‘O,’ ‘A,’ and ‘Asia-1.’ These responses remained above threshold positive level even at day 210 following initial vaccination. Results of sero-surveillance and anecdotal information of repeated FMD outbreaks demonstrate the persistence of FMD virus of yak in northern Pakistan. Laboratory results and field observations clearly indicated that yak can be protected against FMD with a good quality vaccine with FMD serotype(s) matching current, regionally circulating FMD virus.     

Comparative study of experimental Foot-and-Mouth Disease in cattle (<Emphasis Type="Italic">Bos indicus</Emphasis>) and buffaloes (<Emphasis Type="Italic">Bubalis bubalus</Emphasis>)

Foot-and-mouth disease (FMD) is one of the most contagious diseases affecting wide range of host species with variable severity and decreased productivity. The present study was undertaken to compare the clinical and leucocytic changes in indigenous Indian cattle and buffaloes experimentally infected with FMD virus (FMDV) Asia 1. A mild type of disease was observed in the cattle, more so in buffaloes infected with FMDV. Difference in terms of type, site and healing of lesion was observed between cattle and buffaloes. Foot lesions were more common than tongue in buffaloes, which were mainly evident in bulb of the heel in contrast to interdigital foot lesions in cattle. Further, FMDV infection induced a transient moderate leucopenia with lymphopenia in both cattle and buffaloes, but monocyte levels diverged. Relationship between the raised body temperature, leucocytic changes and lesion development was observed. Microscopic changes were observed in the keratinized epithelium of tongue and foot. The findings of the present study indicated the need to investigate the early leucocytic changes in cattle and buffaloes in depth for better understanding of the disease process.     

Putative protective antibody response following oral vaccination of multi-age free ranging helmeted guinea fowls (<Emphasis Type="Italic">Numida meleagris</Emphasis>) with Newcastle disease virus strain I-2 coated on oiled rice

On-farm study was conducted to determine the efficacy of thermostable Newcastle disease (ND) strain I-2 vaccine coated on oiled rice following oral vaccination of multi-age free ranging helmeted guinea fowls. The results from haemagglutination-inhibition assay showed that 7 days after the guinea fowls were orally vaccinated they seroconverted and attained the geometric mean antibody titre (GMT) of 4.9 log₂ (80%). This antibody titre was above the GMT of 3.0 log₂ which is regarded to be protective against field challenge of ND. Furthermore, the results revealed that 28 days after vaccination, the antibody levels reached GMT of 7.6 log₂ (100%). Moreover, all vaccinated guinea fowls survived the challenge of virulent ND virus whereas all unvaccinated chickens died of ND. The findings from the present study showed that the I-2 virus coated on the oiled rice is safe, immunogenic and provoked production of protective antibody response following oral vaccination of helmeted guinea fowls.     

Protection levels of vaccinated pigeons (<Emphasis Type="Italic">Columba livia)</Emphasis> against a highly pathogenic newcastle disease virus strain

The purposes of this study were to model a vaccination regimen for Newcastle disease virus (NDV) in pigeons, and to evaluate the susceptibility and behavior of vaccinated birds against a highly pathogenic NDV Brazilian strain. Antibody response was assessed by means of hemagglutination inhibition test (HI), and viral genome excretion by means of RT-PCR. Vaccinal strains (La Sota and Ulster) induced high antibody titers without any adverse effects, both in inoculated and in sentinel birds. A viral strain pathogenic for chickens did not produce clinical signs of the disease in experimentally infected pigeons. Only 4 out of 10 vaccinated pigeons shed NDV genome, and just for two days. Results confirmed the high infectivity of the vaccinal strains used, as all nonvaccinated pigeons showed antibody titers as high as those of vaccinated birds.     

Protective antibody response following oral vaccination of feral pigeons (<Emphasis Type="Italic">Columba livia</Emphasis>) with Newcastle disease vaccine (strain I-2) coated on oiled rice

The novel vaccination technique for feral pigeons was developed in the present study. Multi-age feral pigeons were vaccinated orally with Newcastle disease (ND) strain I-2 vaccine coated on oiled rice. The results showed that 14 days after vaccination 40% of pigeons seroconverted with HI GMT of ≥3 log₂ whereas 28 days after vaccination the seroconversion rate of these birds reached 100%. Moreover, all vaccinated pigeons survived the challenge of virulent Newcastle disease virus (NDV). The findings from the present study indicated that the use of ND (strain I-2) vaccine in feral pigeons is feasible and resulted into the production of protective antibody response. Thus ND I-2 vaccine may prevent the spread of NDV to other birds particularly chickens. Furthermore the use of oral vaccine in feral multi-age pigeons overcomes the difficulty of catching these birds for individual vaccination.     

Immunoprotection of recombinant <Emphasis Type="Italic">Eg</Emphasis>.P29 against <Emphasis Type="Italic">Echinococcus granulosus</Emphasis> in sheep

Objective

This study aims to investigate the immunoprotection of recombinant Eg.P29 (rEg.P29) vaccine and analyze the underlying mechanism in sheep.

Methods

Three groups of male sheep were immunized subcutaneously with rEg.P29 and PBS, Freund’s complete adjuvant as controls, respectively. After prime-boost vaccination, the sheep were challenged with encapsulated Echinococcus granulosus eggs. The percentage of protection in sheep was determined 36 weeks after the infection. Humoral immune response was analyzed for specific IgG, IgG1, IgG2, IgM and IgE levels. Moreover, cytokines including interferon (IFN)-γ, interleukin (IL)-2, IL-4,and IL-10 were also evaluated.

Results

Immunization with rEg.P29 induced protective immune responses up to 94.5 %, compared with immunoadjuvant group. The levels of specific IgG, IgG1, IgG2, and IgE as well as IFN-γ, IL-2, and IL-4 significantly increased after two immunizations (P < 0.05); however, the levels of IgM and IL-10 did not show difference.

Conclusion

rEg.P29 showed Immunoprotection and induced Th1 and Th2 immune responses; hence, rEg.P29 is a potential vaccine for E. granulosus infection.

     

Detection of infectious bronchitis virus 793B,avian metapneumovirus, <Emphasis Type="Italic">Mycoplasma gallisepticum</Emphasis> and <Emphasis Type="Italic">Mycoplasma synoviae</Emphasis> in poultry in Ethiopia

A survey was conducted into respiratory infectious diseases of poultry on a chicken breeder farm run by the Ethiopian Institute of Agricultural Research (EIAR), located in Debre Zeit, Ethiopia. Oropharyngeal swabs were collected from 117 randomly selected birds, and blood was taken from a subset of 73 of these birds. A combination of serological and molecular methods was used for detection of pathogens. For the first time in Ethiopia, we report the detection of variant infectious bronchitis virus (793B genotype), avian metapneumovirus subtype B and Mycoplasma synoviae in poultry. Mycoplasma gallisepticum was also found to be present; however, infectious laryngotracheitis virus was not detected by PCR. Newcastle disease virus (NDV) was not detected by PCR, but variable levels of anti-NDV HI antibody titres shows possible exposure to virulent strains or poor vaccine take, or both. For the burgeoning-intensive industry in Ethiopia, this study highlights several circulating infectious respiratory pathogens that can impact on poultry welfare and productivity.     

Immune responses to haemorrhagic septicaemia (HS) vaccination in <Emphasis Type="Italic">Trypanosoma evansi</Emphasis> infected buffalo-calves

To assess the immunosuppressive effect of Trypanosoma evansi infection in buffalo-calves on immune responses to heterologous antigen, the study was planned to examine the responses of haemorrhagic septicaemia vaccination in simultaneously and previously (80 days before vaccination) T. evansi-infected buffalo-calves. Eight buffalo-calves were divided into three groups. Buffalo-calves of group A (n = 3) were previously (80 days before primary vaccination with haemorrhagic septicaemia [HS] vaccine) infected with T. evansi (1 × 10⁷ tryps.calf⁻¹; sc) and that of group B (n = 3) were infected with T. evansi (1 × 10⁷ tryps.calf⁻¹; sc) on the day of primary vaccination with HS vaccine. Two healthy uninfected control calves given only HS vaccine were kept in group C. All the buffalo-calves were given a booster dose of vaccine 21 days post-primary vaccination (PPV). Twenty eight days PPV, animals of group A were given trypanocidal quinapyramine prosalt at 6.66 mg kg⁻¹. Immunosuppressive effect of T. evansi infection was evident from day 7 PPV with HS vaccine. The effect was more pronounced in previously T. evansi-infected buffalo-calves as compared with simultaneously infected buffalo-calves. Group A buffalo-calves appeared to have recovered from the immunosuppressive effect after 28 days post-trypanocidal treatment as observed by humoral and cell-mediated immune responses. Immunosuppressive effect to HS vaccination was observed in T. evansi-infected buffalo-calves, and trypanocidal therapy enabled the calves to mount the responses similar to uninfected controls.     

Brucellosis in domestic water buffalo (<Emphasis Type="Italic">Bubalus bubalis</Emphasis>) of Trinidad and Tobago with comparative epidemiology to cattle

The water buffalo is an important domestic animal worldwide, and the local Buffalypso variety was developed in Trinidad to have improved beef qualities. Brucellosis was diagnosed in Trinidad and Tobago during 1998 in both cattle and domestic water buffalo (Bubalus bubalis) populations. Brucellosis in the latter species is caused by infection with Brucella abortus, similar to bovine brucellosis. Control of brucellosis is of paramount importance to preservation of the genetic diversity of these animals in Trinidad, and this has been complicated by differences in the epidemiology of water buffalo and bovine brucellosis. Some diagnostic tests do not have comparable accuracy between the two species, and the RB51 vaccine does not adequately protect against infection in water buffalo. The water buffalo in Trinidad may also be more resistant to infection than cattle. Development of effective vaccination protocols is key to brucellosis control in Buffalypso in Trinidad, and prohibitions on import of virulent B. abortus strains for vaccine efficacy studies has impeded progress in this area. These Trinidadian strains are of variable virulence; some might be effective for challenge in vaccine efficacy studies, while other, of lower virulence, may be vaccine candidates for use in water buffalo.     

Experimental infection of <Emphasis Type="Italic">Peste des Petit Ruminant</Emphasis> virus and <Emphasis Type="Italic">Mannheimia haemolytica</Emphasis> A2 in goats: immunolocalisation of <Emphasis Type="Italic">Mannheimia haemolytica</Emphasis> antigens

Nigerian strain of Peste des Petit Ruminant (PPR) virus and Mannheimia haemolytica (MH) biotype A serotype 2, was used successfully to reproduce a concurrent disease in West African Dwarf goats. The development of the various pathological features were studied at regular intervals following infection. The acute inflammatory reaction which had developed by day 3 after initial infection was characterised by flooding of the alveoli by neutrophils, oedema, hemorrhage and syncytial cells together with a moderate bronchial and bronchiolar epithelial necrosis. This progressed to a milder acute broncho interstitial pneumonia with giant cells. At this stage, the mucosal immunity were well developed especially the aggregate form of NALT and more of nodular forms of BALT. The organisms were demonstrated with strong immunostaining in the necrotic center, necrotic alveolar wall, fibrin, serous exudate, and degenerated leukocyte in the alveoli and respiratory airways. The bacterial antigens were observed as a strong immunostaining in the blood vessels of the nasal septum, sinusoid in the liver and interstium of the kidney, cytoplasm of alveolar macrophages, pneumocytes, bronchial and bronchiolar epithelium, in the monocytes in the blood vessels. These findings confirmed the enhancement of MH tropism especially in the respiratory tract, liver and kidney. It also showed that West african dwarf goats are highly susceptible to the intratracheal combined infection of PPR virus and MH. The fact that the infection induces strong mucosal responses, this phenomenon can be explored in Africa with the use of combined PPR virus and MH intranasal vaccines to curtail the menace of pneumonia associated with the combined infection on field.     

<Emphasis Type="Italic">Theileria</Emphasis> (<Emphasis Type="Italic">Babesia</Emphasis>) <Emphasis Type="Italic">equi</Emphasis> and <Emphasis Type="Italic">Babesia caballi</Emphasis> Infections in Horses in Galicia,Spain

The control of equine piroplasmosis is becoming increasingly important to maintain the international market open to the horse industry. The purpose of this study was to demonstrate the occurrence of equine piroplasmosis (Theileria equi and Babesia caballi) in Galicia, north-west Spain, and to compare haematological and serum biochemistry parameters between non-parasitaemic horses and horses parasitaemic with T. equi and B. caballi. Sixty serum samples (control group) were taken from healthy horses pastured on two farms, and examined for evidence of equine T. equi and B. caballi infection by indirect fluorescent antibody test (IFAT). Of the 60 samples, 24 (40%) and 17 (28.3%) samples were positive for T. equi and B. caballi, respectively. Twelve (20%) samples were positive for both parasites. Haematology and serum biochemistry were compared between controls and a series of 36 horses clinically affected by T. equi (25) or B. caballi (11). Compared with the healthy group, there was a 43% and 37% decrease in the haematocrit for T. equi and B. caballi infection, respectively. Parasitaemic horses presented an intense anaemia and serum biochemistry signs of liver damage. The anaemia was more severe in T. equi-infected than in B. caballi-infected horses. Our results suggest that equine piroplasmosis is widespread in the region and is a cause for concern.     

Effectiveness of vaccines and vaccination programs for the control of foot-and-mouth disease in Uganda, 2001–2010

Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals. In Uganda, FMD outbreaks are mainly controlled by ring vaccination and restriction of animal movements. Vaccination stimulates immunity and prevents animals from developing clinical signs which include lameness, inappetence, and decreased production. Ring vaccination and restriction of animal movements have, however, not successfully controlled FMD in Uganda and outbreaks reoccur annually. The objective of this study was to review the use of FMD virus (FMDV) vaccines and assess the effectiveness of vaccination programs for controlling FMD in Uganda (2001–2010), using retrospective data. FMD vaccine distribution patterns in Uganda (2001–2010) matched occurrence of outbreaks with districts reporting the highest number of outbreaks also receiving the largest quantity of vaccines. This was possibly due to “fire brigade” response of vaccinating animals after outbreaks have been reported. On average, only 10.3 % of cattle within districts that reported outbreaks during the study period were vaccinated. The average minimum time between onset of outbreaks and vaccination was 7.5 weeks, while the annual cost of FMDV vaccines used ranged from US $58,000 to 1,088,820. Between 2001 and 2010, serotyping of FMD virus was done in only 9/121 FMD outbreaks, and there is no evidence that vaccine matching or vaccine potency tests have been done in Uganda. The probability of FMDV vaccine and outbreak mismatch, the delayed response to outbreaks through vaccination, and the high costs associated with importation of FMDV vaccines could be reduced if virus serotyping and subtyping as well as vaccine matching were regularly done, and the results were considered for vaccine manufacture.     

Foot-and-mouth disease (FMD) in the Maghreb and its threat to southern European countries

Foot-and-mouth disease (FMD) is a highly contagious and transboundary viral disease of domesticated and wild cloven-hoofed animals. The present study summarizes the knowledge generated from the epidemiology, diagnosis, and surveillance of the disease in the Maghreb (2014–2015) in assessing its threat to southern European countries. Currently, two serotypes of the FMD virus (O and SAT-2) and four lineages are circulating in the Maghreb region. The introduction of serotype SAT-2 in Libya and Mauritania in 2012 and 2015 respectively sets their neighbors and subsequently south European countries at constant risk of FMD re-emergence. The potential pathways of FMD introduction to southern European countries from the Maghreb are the illegal introduction of infected animals and animal products, particularly meat or meat products carried by refugees.

     

Seroprevalence of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> infection in yaks (<Emphasis Type="Italic">Bos grunniens</Emphasis>) in northwestern China

The seroprevalence of Toxoplasma gondii infection in yaks (Bos grunniens) was surveyed in Qinghai Province, northwestern China in May and June 2010. A total of 650 serum samples were collected from six counties and assayed for T. gondii antibodies by an indirect hemagglutination test. Antibodies to T. gondii were found in 35.08% (228/650) with the highest rate of 55.34% in Chengduo County. The results of the present survey indicated that infection with T. gondii in cattle is widely spread in China, including yaks in Qinghai Province.     

Early antibody responses of cattle for foot-and-mouth disease quadrivalent double oil emulsion vaccine

Foot-and-mouth disease (FMD) is an economically important disease of cloven-hoofed animals. The multiplicity of FMDV serotypes in animals poses a central problem in the policy of vaccination and is of much concern to health authorities. Hence it is the practice of vaccination with polyvalent vaccine for prophylactic measure. In the present report, we analysed the early antibody responses elicited by FMDV quadrivalent (FMDV O, A, C and Asia 1 serotypes) double emulsion (Montanide ISA 206) vaccines in cattle. We observed variations between various viral serotypes in eliciting early antibody response although neutralizing antibody response against all the four serotypes were detected as early as fourth day following vaccination. The duration of immunity also appeared to maintain for long period. The neutralizing antibody titres were maintained well above 2log(10) even after 6 months of vaccination irrespective of serotypes. Thus, allows the possibilities of two vaccinations per year for the maintenance of herd immunity.     

Seroprevalence of <Emphasis Type="Italic">Anaplasma marginale</Emphasis> and <Emphasis Type="Italic">Babesia bigemina</Emphasis> infections and associated risk factors in Machakos County,Kenya

Anaplasma marginale and Babesia bigemina are important tick-borne pathogens of cattle. A cross-sectional survey was undertaken to determine the seroprevalence of A. marginale and B. bigemina infections and identify associated risk factors on traditional smallholder farms in Machakos County, Kenya. A total of 421 cattle from 127 farms from four divisions in the county were sampled and visited between September and November 2007. The farms were selected by a proportional allocation approach based on the number of farms in the four divisions previously selected by stratified random sampling method. Information on animal and individual farm management variables was obtained using standardized questionnaires. Prevalence of serum antibodies due to A. marginale and B. bigemina pathogens was determined using the enzyme-linked immunosorbent assay (ELISA) technique. The relationship between the seropositivity and associated risk factors was assessed by multivariable analyses using standard logistic regression models. The overall estimation (and their 95% confidence intervals) of A. marginale and B. bigemina seropositivity at the animal level was 53.4% (48.5%, 58.2%) and 40.6% (35.8%, 45.4%), respectively. Two variables, “animal age” and “administrative division,” were significantly associated with the A. marginale seroresponse. Three variables, “animal age” “grazing system” and “administrative division” were significantly associated with the B. bigemina seroresponse. These findings suggest possible indicators of existence of endemic instability for the two infections. The study identifies characterization of environmental suitability for the vectors and how they interact with grazing systems to cause the infections as an area for further studies, for improved understanding of the infections and in designing disease control programs.     

The effectiveness of foot-and-mouth disease vaccines in Switzerland. II. Stability problems

One of the vaccines that were used in 1988 to immunize the Swiss national cattle population against foot-and mouth disease (FMD) was apparently not stable. Data, provided by the manufacturer, indicated a high initial antigenic content for serotype O. Protection experiments at the end of the vaccination campaign, however, indicated a substantial loss of serotype O antigen in the vaccine. Serological data, obtained during the campaign indicated that only 12% of the primovaccinated animals and 63% of previously vaccinated animals received an amount of FMD viral antigen sufficient to induce protective immunity. The primovaccinated animals were revaccinated in fall 1988 with a new batch provided by the same manufacturer. The new vaccine induced high titers of neutralizing antibodies in primo- and an anamnestic response in revaccinated cattle.     

Biological control of <Emphasis Type="Italic">Ascaris suum</Emphasis> eggs by <Emphasis Type="Italic">Pochonia chlamydosporia</Emphasis> fungus

Ascaris suum is a gastrointestinal nematode parasite of swines. The aim of this study was to observe Pochonia chlamydosporia fungus on biological control of A. suum eggs after fungus passage through swines gastrointestinal tract. Eighteen pigs, previously dewormed, were randomly divided into three groups: group 1, treated with the fungus isolate VC4; group 2, treated with the fungus isolate VC1 and group 3 did not receive fungus (control). In the treated groups, each animal received a 9 g single dose of mycelium mass containing P. chlamydosporia (VC1 or VC4). Thereafter, animal fecal samples were collected at the following intervals: 8, 12, 24, 36, 48, 72 and 96 h after treatment beginning and these were poured in Petri dishes containing 2% water-agar culture medium. Then, 1,000 A. suum eggs were poured into each dish and kept in an incubator at 26°C and in the dark for 30 days. After this period, approximately 100 eggs were removed from each Petri dish and morphologically analyzed under light microscopy following the ovicidal activity parameters. The higher percentage observed for isolated VC4 eggs destruction was 57.5% (36 h) after fungus administration and for isolate VC1 this percentage was 45.8% (24 h and 72 h) (p > 0.01). P. chlamydosporia remained viable after passing through the gastrointestinal tract of swines, maintaining its ability of destroying A. suum eggs.     

Seasonal variations in plasma glucocorticoid levels in yaks (<Emphasis Type="Italic">Poephagus grunniens L</Emphasis>.) (<Emphasis Type="Italic">Bos grunniens</Emphasis>)

The changes of glucocorticoid concentrations were measured by highly sensitive enzymeimmunoassay procedures using second antibody coating technique and cortisol -HRP amplified system for one whole calendar year in yaks. The year was divided into seasons of cool, intermediate and hot seasons. The glucocorticoid values were lower (P < .01) in hotter months than in cool and intermediate seasons. Rectal temperature and respiration rates were indicative of heat stress in the hot temperature season and gave significant negative correlation with circulating corticoid concentration.