A survey amongst sheep and goat producers and veterinarians was undertaken to collect epidemiological data on orf in South Africa. Previous epidemiological studies on the presence of the disease in the country have not been documented and this report is the first descriptive epidemiological study of orf in South Africa. A seven-month investigation, realised by direct and indirect interviews and field observation, enabled us to outline incidence and risk factors of this disease and to better understand how the local farmers in rural areas relate to it. The results may contribute to better management of the disease in rural areas. By means of molecular analyses the phylogenetic relationships between field isolates from different areas have been identified. The findings gave a first important contribution to the general assessment of the economic impact of orf virus infections and the extent of the risk to human health.

A survey amongst sheep and goat producers and veterinarians was undertaken to collect epidemiological data on orf in South Africa. Previous epidemiological studies on the presence of the disease in the country have not been documented and this report is the first descriptive epidemiological study of orf in South Africa. A seven-month investigation, realised by direct and indirect interviews and field observation, enabled us to outline incidence and risk factors of this disease and to better understand how the local farmers in rural areas relate to it. The results may contribute to better management of the disease in rural areas. By means of molecular analyses the phylogenetic relationships between field isolates from different areas have been identified. The findings gave a first important contribution to the general assessment of the economic impact of orf virus infections and the extent of the risk to human health.

The aims of this study were to determine the modulating role of ascorbic acid (AA) on rectal temperature (RT), heterophil to lymphocyte (H to L) ratio and aberrant behaviours of ostrich chicks transported by road for 4 h during hot-dry conditions. Twenty ostrich chicks aged 2.5 months, of both sexes and belonging to the Red Neck breed, served as subjects of the study. The chicks were assigned randomly to AA-treated and control groups, consisting of 10 chicks each. The AA-treated group was administered orally with 100 mg/kg body weight of AA dissolved in 5 mL of sterile water 30 min before transportation, whilst the control group was given the equivalent of sterile water only. The thermal load (TL) experienced in the vehicle during transportation fluctuated between 31 °C and 89 °C, as calculated from the ambient temperature and relative humidity. Transportation induced hyperthermia, lymphopenia, heterophilia and aberrant behaviours of pecking, wing fluffing and panting, which were ameliorated by AA administration. The relationships between the TL, journey duration and physiological variables of RT, H to L ratio and aberrant behaviours recorded during transportation were significantly and positively correlated in the control group. In AA-treated group the relationships were not significantly correlated. In conclusion, the results showed for the first time that AA ameliorated the adverse effects of stress caused by road transportation on the aberrant behaviours, RT and H to L ratio of ostrich chicks during the hot-dry season.

The aims of this study were to determine the modulating role of ascorbic acid (AA) on rectal temperature (RT), heterophil to lymphocyte (H to L) ratio and aberrant behaviours of ostrich chicks transported by road for 4 h during hot-dry conditions. Twenty ostrich chicks aged 2.5 months, of both sexes and belonging to the Red Neck breed, served as subjects of the study. The chicks were assigned randomly to AA-treated and control groups, consisting of 10 chicks each. The AA-treated group was administered orally with 100 mg/kg body weight of AA dissolved in 5 mL of sterile water 30 min before transportation, whilst the control group was given the equivalent of sterile water only. The thermal load (TL) experienced in the vehicle during transportation fluctuated between 31 °C and 89 °C, as calculated from the ambient temperature and relative humidity. Transportation induced hyperthermia, lymphopenia, heterophilia and aberrant behaviours of pecking, wing fluffing and panting, which were ameliorated by AA administration. The relationships between the TL, journey duration and physiological variables of RT, H to L ratio and aberrant behaviours recorded during transportation were significantly and positively correlated in the control group. In AA-treated group the relationships were not significantly correlated. In conclusion, the results showed for the first time that AA ameliorated the adverse effects of stress caused by road transportation on the aberrant behaviours, RT and H to L ratio of ostrich chicks during the hot-dry season.

Freshwater snails are known to serve as first intermediate hosts for various parasitic diseases such as schistosomosis, amphistomosis and fasciolosis. Two freshwater snail species, Lymnaea natalensis, Krauss 1848 and Bulinus tropicus, Krauss 1848 were sampled from five localities in Gauteng and one locality in the North West Province from 2007 to 2010. These snails were collected in order to study their cercarial sheddings. They were found to be infected with three different types of strigea cercariae, of which the morphology was studied using standard light and scanning electron microscopy techniques.

Freshwater snails are known to serve as first intermediate hosts for various parasitic diseases such as schistosomosis, amphistomosis and fasciolosis. Two freshwater snail species, <em>Lymnaea natalensis</em>, Krauss 1848 and <em>Bulinus tropicus</em>, Krauss 1848 were sampled from five localities in Gauteng and one locality in the North West Province from 2007 to 2010. These snails were collected in order to study their cercarial sheddings. They were found to be infected with three different types of strigea cercariae, of which the morphology was studied using standard light and scanning electron microscopy techniques.

The use of 1.16 mg/kg (one third) of the recommended dose of diminazene aceturate, administered indiscriminately to cattle on day seven of the unfrozen Babesia bovis and Babesia bigemina bivalent live blood vaccine reaction, was an infection and block treatment method of immunisation used successfully with no known adverse effect on the parasites or the development of protective immunity. Continuing with this practice after replacement of the unfrozen vaccine with deep-frozen monovalent B. bovis and B. bigemina live blood vaccines resulted in reports of vaccine failure. Laboratory investigation indicated the harmful effect of block treatment in preventing the development of durable immunity against B. bigemina as opposed to the much lesser effect it had on B. bovis. Consequently the practice was no longer recommended. A B. bovis vaccination attempt aimed at controlling the disease of dairy cows in milk (n = 30) resulted in 20% fatalities during the expected vaccine reaction period. The practice of block treating B. bovis was therefore reinvestigated, this time in a field trial using dairy cattle in milk (n = 11). Using 0.88 mg/kg (one quarter) of the recommended dose of diminazene administered on day 12 of the B. bovis vaccine reaction resulted in only two animals (n = 5) testing ≥ 1/80 positive with the indirect fluorescent antibody test (IFAT) although parasites could be demonstrated in three. In the untreated control group, by contrast, five of the vaccinated animals (n = 6) tested ≥ 1/80 positive with IFAT and parasites could be demonstrated in all. The unsatisfactory outcome obtained in this study, combined with that of the earlier investigation, indicated that there are more factors that influence successful vaccination than previously considered. It is therefore concluded that block treatment of the live frozen South African cattle babesiosis vaccines reactions is not recommended.

The use of 1.16 mg/kg (one third) of the recommended dose of diminazene aceturate, administered indiscriminately to cattle on day seven of the unfrozen <em>Babesia bovis</em> and <em>Babesia bigemina</em> bivalent live blood vaccine reaction, was an infection and block treatment method of immunisation used successfully with no known adverse effect on the parasites or the development of protective immunity. Continuing with this practice after replacement of the unfrozen vaccine with deep-frozen monovalent <em>B. bovis</em> and <em>B. bigemina</em> live blood vaccines resulted in reports of vaccine failure. Laboratory investigation indicated the harmful effect of block treatment in preventing the development of durable immunity against <em>B. bigemina</em> as opposed to the much lesser effect it had on <em>B. bovis</em>. Consequently the practice was no longer recommended. A <em>B. bovis</em> vaccination attempt aimed at controlling the disease of dairy cows in milk (<em>n</em> = 30) resulted in 20% fatalities during the expected vaccine reaction period. The practice of block treating <em>B. bovis</em> was therefore reinvestigated, this time in a field trial using dairy cattle in milk (<em>n</em> = 11). Using 0.88 mg/kg (one quarter) of the recommended dose of diminazene administered on day 12 of the <em>B. bovis</em> vaccine reaction resulted in only two animals (<em>n</em> = 5) testing ≥ 1/80 positive with the indirect fluorescent antibody test (IFAT) although parasites could be demonstrated in three. In the untreated control group, by contrast, five of the vaccinated animals (<em>n</em> = 6) tested ≥ 1/80 positive with IFAT and parasites could be demonstrated in all. The unsatisfactory outcome obtained in this study, combined with that of the earlier investigation, indicated that there are more factors that influence successful vaccination than previously considered. It is therefore concluded that block treatment of the live frozen South African cattle babesiosis vaccines reactions is not recommended.

The epidemiology of orf virus infection in Saudi Arabia (SA) has been researched since 1990. The results obtained during this period indicate that the disease is widespread, has great economic impact and that no vaccine has been used against it. The present study compares the immunogenicity and protective efficacy of three locally developed live orf virus vaccines. Two of them differ in their passage history in Vero cell culture and the third was used as a virulent virus in glycerine buffer. To the best of the authors’ knowledge, no similar comparative study has been conducted in the Middle East utilising three types of vaccines prepared from the same virus strain. Selection of the candidate seed orf virus and performance of the quality control tests were as laid out by the OIE for veterinary vaccine production. The vaccine seed virus was a field orf virus isolated from a previous orf outbreak in Saudi Arabia. A simple novel formula was developed to calculate the rate of reduction in the healing time (RHT %) in the challenged sheep. This allowed direct comparison of the efficacy of the three types of vaccines employed in the present study. The efficacy of each vaccine was tested on a cohort of local Noemi sheep.

The epidemiology of orf virus infection in Saudi Arabia (SA) has been researched since 1990. The results obtained during this period indicate that the disease is widespread, has great economic impact and that no vaccine has been used against it. The present study compares the immunogenicity and protective efficacy of three locally developed live orf virus vaccines. Two of them differ in their passage history in Vero cell culture and the third was used as a virulent virus in glycerine buffer. To the best of the authors’ knowledge, no similar comparative study has been conducted in the Middle East utilising three types of vaccines prepared from the same virus strain. Selection of the candidate seed orf virus and performance of the quality control tests were as laid out by the OIE for veterinary vaccine production. The vaccine seed virus was a field orf virus isolated from a previous orf outbreak in Saudi Arabia. A simple novel formula was developed to calculate the rate of reduction in the healing time (RHT %) in the challenged sheep. This allowed direct comparison of the efficacy of the three types of vaccines employed in the present study. The efficacy of each vaccine was tested on a cohort of local Noemi sheep.

Reliable results represent the pinnacle assessment of quality of an analytical laboratory, and therefore variability is considered to be a critical quality problem associated with the selenium analysis method executed at Western Cape Provincial Veterinary Laboratory (WCPVL). The elimination and control of variability is undoubtedly of significant importance because of the narrow margin of safety between toxic and deficient doses of the trace element for good animal health. A quality methodology known as Lean Six Sigma was believed to present the most feasible solution for overcoming the adverse effect of variation, through steps towards analytical process improvement. Lean Six Sigma represents a form of scientific method type, which is empirical, inductive and deductive, and systematic, which relies on data, and is fact-based. The Lean Six Sigma methodology comprises five macro-phases, namely Define, Measure, Analyse, Improve and Control (DMAIC). Both qualitative and quantitative laboratory data were collected in terms of these phases. Qualitative data were collected by using quality-tools, namely an Ishikawa diagram, a Pareto chart, Kaizen analysis and a Failure Mode Effect analysis tool. Quantitative laboratory data, based on the analytical chemistry test method, were collected through a controlled experiment. The controlled experiment entailed 13 replicated runs of the selenium test method, whereby 11 samples were repetitively analysed, whilst Certified Reference Material (CRM) was also included in 6 of the runs. Laboratory results obtained from the controlled experiment was analysed by using statistical methods, commonly associated with quality validation of chemistry procedures. Analysis of both sets of data yielded an improved selenium analysis method, believed to provide greater reliability of results, in addition to a greatly reduced cycle time and superior control features. Lean Six Sigma may therefore be regarded as a valuable tool in any laboratory, and represents both a management discipline, and a standardised approach to problem solving and process optimisation.

Reliable results represent the pinnacle assessment of quality of an analytical laboratory, and therefore <em>variability</em> is considered to be a critical quality problem associated with the selenium analysis method executed at Western Cape Provincial Veterinary Laboratory (WCPVL). The elimination and control of variability is undoubtedly of significant importance because of the narrow margin of safety between toxic and deficient doses of the trace element for good animal health. A quality methodology known as Lean Six Sigma was believed to present the most feasible solution for overcoming the adverse effect of variation, through steps towards analytical process improvement. Lean Six Sigma represents a form of scientific method type, which is empirical, inductive and deductive, and systematic, which relies on data, and is fact-based. The Lean Six Sigma methodology comprises five macro-phases, namely Define, Measure, Analyse, Improve and Control (DMAIC). Both qualitative and quantitative laboratory data were collected in terms of these phases. Qualitative data were collected by using quality-tools, namely an Ishikawa diagram, a Pareto chart, Kaizen analysis and a Failure Mode Effect analysis tool. Quantitative laboratory data, based on the analytical chemistry test method, were collected through a controlled experiment. The controlled experiment entailed 13 replicated runs of the selenium test method, whereby 11 samples were repetitively analysed, whilst Certified Reference Material (CRM) was also included in 6 of the runs. Laboratory results obtained from the controlled experiment was analysed by using statistical methods, commonly associated with quality validation of chemistry procedures. Analysis of both sets of data yielded an improved selenium analysis method, believed to provide greater reliability of results, in addition to a greatly reduced cycle time and superior control features. Lean Six Sigma may therefore be regarded as a valuable tool in any laboratory, and represents both a management discipline, and a standardised approach to problem solving and process optimisation.

In this study we examined the anti-tick properties of the essential oil of Tagetes minuta L. (Asteraceae: Asterales) against Hyalomma rufipes ticks. We obtained the essential oil of T. minuta by hydro-distillation of a combination of fresh flowers, leaves and soft stems, and analysed these by using gas chromatography (GC) and gas chromatography-linked mass spectrometry (GC-MS). The oil had a high percentage of monoterpenes and the major compounds identified were cis-ocimene (28.5%), beta-ocimene (16.83%) and 3-methyl-2-(2-methyl-2-butenyl)-furan (11.94%). Hyalomma rufipes adults displayed a significant (P  0.05) dose repellent response to the essential oil of T. minuta. Probit analysis indicated a repellent EC50 of T. minuta essential oil for male ticks to be 0.072 mL/mL (CI 0.053 mL/mL to 0.086 mL/mL) and 0.070 mL/mL (CI 0.052 mL/mL to 0.084 mL/mL) for female ticks. There were no significant differences in repellent responses between male and female ticks. The oil also significantly (P  0.05) delayed moulting of 60% of H. rufipes engorged nymphs. These results suggest that T. minuta may be a potential source of anti-tick agents.

In this study we examined the anti-tick properties of the essential oil of Tagetes minuta L. (Asteraceae: Asterales) against Hyalomma rufipes ticks. We obtained the essential oil of T. minuta by hydro-distillation of a combination of fresh flowers, leaves and soft stems, and analysed these by using gas chromatography (GC) and gas chromatography-linked mass spectrometry (GC-MS). The oil had a high percentage of monoterpenes and the major compounds identified were cis-ocimene (28.5%), beta-ocimene (16.83%) and 3-methyl-2-(2-methyl-2-butenyl)-furan (11.94%). Hyalomma rufipes adults displayed a significant (P < 0.05) dose repellent response to the essential oil of T. minuta. Probit analysis indicated a repellent EC50 of T. minuta essential oil for male ticks to be 0.072 mL/mL (CI 0.053 mL/mL to 0.086 mL/mL) and 0.070 mL/mL (CI 0.052 mL/mL to 0.084 mL/mL) for female ticks. There were no significant differences in repellent responses between male and female ticks. The oil also significantly (P < 0.05) delayed moulting of 60% of H. rufipes engorged nymphs. These results suggest that T. minuta may be a potential source of anti-tick agents.

A cross-sectional study was conducted in five provinces and 11 districts of Zambia to determine the seroprevalence of Newcastle disease in Zambian backyard chicken flocks. Of the chickens sampled, 73.9% tested positive for avian paramyxovirus type 1 antibodies by means of an enzyme-linked immunosorbent assay. Seroprevalence varied amongst the five provinces sampled, ranging from 82.6% in the Eastern Province to 48.3% in Luapula Province. Seroprevalence also varied amongst the 11 districts sampled, ranging from 91.3% in Monze district of Southern Province to 22.8% in Mufulira district of the Copperbelt province. Overall, the seroprevalence of Newcastle disease in Zambian backyard chicken flocks has increased since the previous study conducted in 1994.

A cross-sectional study was conducted in five provinces and 11 districts of Zambia to determine the seroprevalence of Newcastle disease in Zambian backyard chicken flocks. Of the chickens sampled, 73.9% tested positive for avian paramyxovirus type 1 antibodies by means of an enzyme-linked immunosorbent assay. Seroprevalence varied amongst the five provinces sampled, ranging from 82.6% in the Eastern Province to 48.3% in Luapula Province. Seroprevalence also varied amongst the 11 districts sampled, ranging from 91.3% in Monze district of Southern Province to 22.8% in Mufulira district of the Copperbelt province. Overall, the seroprevalence of Newcastle disease in Zambian backyard chicken flocks has increased since the previous study conducted in 1994.

The first collection of unengorged and fully engorged larvae of Nuttalliella sp. (N. namaqua?) from the murid rodents Micaelamys namaquensis, Aethomys chrysophilus and Acomys spinosissimus in Limpopo Province and from M. namaquensis in the Northern Cape Province, South Africa, is documented. A total of nine larvae were collected from two M. namaquensis in the Soutpansberg mountain range in the Limpopo Province during April 2009. During the last week of September 2011, 221 larvae were collected from rodents at the same locality and 10 of 48 M. namaquensis, 6 of 12 Ae. chrysophilus and 3 of 14 Ac. spinosissimus were infested. One of the M. namaquensis harboured 53 larvae. Five larvae were collected from two M. namaquensis in the Northern Cape Province. Total genomic DNA was extracted from two larvae and a region of the 18S rRNA gene was sequenced for these. BLASTn searches revealed similarity between these specimens and the Nuttalliella sequences published on GenBank.

CITATION: Horak, I. G. et al. 2012. Natural hosts of the larvae of Nuttalliella sp. (N. namaqua?) (Acari: Nuttalliellidae). Onderstepoort Journal of Veterinary Research, 79(1), Art. #405, doi:10.4102/ojvr.v79i1.405. | The original publication is available at http://www.ojvr.org | The first collection of unengorged and fully engorged larvae of Nuttalliella sp. (N. namaqua?) from the murid rodents Micaelamys namaquensis, Aethomys chrysophilus and Acomys spinosissimus in Limpopo Province and from M. namaquensis in the Northern Cape Province, South Africa, is documented. A total of nine larvae were collected from two M. namaquensis in the Soutpansberg mountain range in the Limpopo Province during April 2009. During the last week of September 2011, 221 larvae were collected from rodents at the same locality and 10 of 48 M. namaquensis, 6 of 12 Ae. chrysophilus and 3 of 14 Ac. spinosissimus were infested. One of the M. namaquensis harboured 53 larvae. Five larvae were collected from two M. namaquensis in the Northern Cape Province. Total genomic DNA was extracted from two larvae and a region of the 18S rRNA gene was sequenced for these. BLASTn searches revealed similarity between these specimens and the Nuttalliella sequences published on GenBank. © 2012. The Authors. | http://www.ojvr.org/index.php/ojvr/article/view/405 | Publisher's version

The first collection of unengorged and fully engorged larvae of Nuttalliella sp. (N. namaqua?) from the murid rodents Micaelamys namaquensis, Aethomys chrysophilus and Acomys spinosissimus in Limpopo Province and from M. namaquensis in the Northern Cape Province, South Africa, is documented. A total of nine larvae were collected from two M. namaquensis in the Soutpansberg mountain range in the Limpopo Province during April 2009. During the last week of September 2011, 221 larvae were collected from rodents at the same locality and 10 of 48 M. namaquensis, 6 of 12 Ae. chrysophilus and 3 of 14 Ac. spinosissimus were infested. One of the M. namaquensis harboured 53 larvae. Five larvae were collected from two M. namaquensis in the Northern Cape Province. Total genomic DNA was extracted from two larvae and a region of the 18S rRNA gene was sequenced for these. BLASTn searches revealed similarity between these specimens and the Nuttalliella sequences published on GenBank.