A study of some infectious causes of reproductive disorders in cattle owned by resource-poor farmers in Gauteng Province, South Africa.

Two hundred and thirty-nine cattle from Gauteng Province in South Africa were tested for various pathogens causing reproductive diseases includingbovine viral diarrhoea/mucosal disease (BVD/MD) virus, infectious bovine rhinotracheitis/infectious pustular vulvovaginitis (IBR/IPV) virus, Neospora caninum and Brucella abortus usingvarious tests. For BVD/MD virus, 49.37% tested positive, 74.47% for IBR/IPV virus, 8.96% for Neospora caninum and 3.8% for Brucella abortus. The result for Brucella abortus is higher than the national average, possibly due to the small sample size. A high seroprevalence of antibodies to both BVD/MD virus and IBR/IPV virus was evident. These 2 viruses should be considered, in addition to Brucella abortus, when trying to establish causes of abortion in cattle. The clinical significance of Neospora caninum as a cause of abortion in Gauteng needs further investigation. One hundred and forty-three bulls were tested for Campylobacter fetus and Trichomonas fetus, and a low prevalence of 1.4% and 2.1% respectively was found in this study. The clinical implications of these findings are discussed.

A literature review and investigation of staphylococcal necrotic dermatitis in sheep.

An outbreak of necrotic dermatitis in sheep was intensively investigated. Initially 19 of 147 Letelle (Merino-type) ewes were identified but closer inspection revealed 57 sheep that had skin lesions, some very slight, and that the majority (46 or 80%) had lesions only above the lips. A small number of them had multiple lesions on the legs or vulvae apart from lip lesions. Seven had only vulvar lesions and 2 only leg lesions. Among the sheep with lip lesions, twice as many had lesions on the right as on the left. Electron micrographs did not reveal any virus particles from the lesions, but all bacterial swabs yielded pure cultures of beta-haemolytic, Gram-positive cocci that were catalase, coagulase and DNase positive. The organism was identified as Staphylococcus aureus. Histopathology was consistent with a dermotoxic insult. A review of available literature indicated that this outbreak was consistent with a diagnosis of ovine necrotic (staphylococcal) dermatitis, supported by data on signalment, lesions, distribution, size, number, epidemiology as well as specific tests. The range of differential diagnoses and possible confusers are discussed.

Retrospective study on the incidence of Salmonella isolations in animals in South Africa, 1996 to 2006.

A retrospective study that involves the analysis of laboratory diagnostic data collected during the period 1996-2006 was conducted. A total of 3417 Salmonella isolations involving 183 different serotypes was recorded from 1999-2006, inclusive, at the Onderstepoort Veterinary Institute, Agricultural Research Council, South Africa. The most common serotypes were Salmonella enterica subspecies enterica serovar Typhimurium (917 incidents), Salmonella enterica subspecies enterica serovar Dublin (248 incidents), Salmonella enterica subspecies enterica serovar Enteritidis (232 incidents), Salmonella enterica subspecies enterica serovar Muenchen (164 incidents), Salmonella enterica subspecies enterica serovar Heidelberg (118 incidents) and Salmonella enterica subspecies enterica serovar Chester (113 incidents). The number of recorded Salmonella isolations over the period 1996 to 2006 varies considerably from year to year The peak of 693 isolations was recorded in 1997, and the lowest, 108 incidents, in 2001. Of the total incidents recorded during the period of survey, 2410 (70.5%) occurred in poultry and other birds, 641 (18.75%) occurred in cattle, 255 (7.46) in pigs and 111 (3.24%) in sheep. Despite the large number of serotypes isolated (183), 52 % of incidents were due to only 6 serotypes in decreasing order of prevalence: S. Typhimurium, S. Dublin, S. Enteritidis, S. Muenchen, S. Heidelberg and S. Chester. Serovar Typhimurium was the most common serotype and was detected in all animal species sampled, with, 65% (598) of the incidents occurring in poultry and 20% (187) occurring in cattle. Of the total of 248 incidents of S. Dublin serotype, 95.6% (237) of incidents occurred in cattle and of the 232 isolates of S. Enteritidis, 223 (96%) originated from poultry. Serovar Choleraesuis was identified in 16 isolates from pigs. The following 4 serotypes were each recorded in more than 50 incidents: S. Hadar (102), S. Schwarzengrund (99), S. Mbandaka (94) and S. Sandiego (73). The trends of annual incidence of Salmonella infection in cattle, sheep, pigs, poultry and other birds during the 11-year period and the distribution of the main serotypes in individual species of animals from 1996-2006 are discussed.

Ulcerative balanitis and vulvitis of Dorper sheep in South Africa: a study on its aetiology and clinical features.

Ovine ulcerative balanitis and vulvitis in sheep of the Dorper breed has been observed in South Africa since 1979. Its aetiology has not been conclusively resolved, and there is some discrepancy in descriptions of its clinical features. In order to identify the pathogenic micro-organism/s that contribute to the occurrence of the disease, the microflora in the genital tracts of both clinically healthy and affected sheep were isolated and compared. Bacteriological examination of materials from affected and unaffected sheep resulted in the isolation of Arcanobacterium pyogenes from 44.2% and 17.2% of them respectively. This difference is statistically significant (P < 0.01). Seventy-four per cent of the isolates originated from severe clinical cases. Mycoplasmas were isolated from 49.3% of 116 clinically normal sheep and 78.2% of 104 affected sheep. There were significant differences in their rates of isolation in clinical groups (P < 0.05). Of all the mycoplasma isolates, Mycoplasma mycoides mycoides large colony variant (MmmLC) was isolated from 61.5% of clinically diseased sheep while 6.0% of the isolates were from apparently healthy animals (P < 0.05). The study threw light on the prevalence of mycoplasmas in the genital tract of apparently healthy sheep and, at the same time the identity of the mycoplasma pathogen associated with ulcerative balanitis and vulvitis was revealed. The findings of this investigation therefore confirmed the involvement of mycoplasma, particularly that of MmmLC large colony, in the disease in Dorper sheep in South Africa, and it was concluded that this microorganism is an important pathogen of balanitis and vulvitis in them. The study furthermore demonstrated a probable synergism between A. pyogenes and MmmLC. Finding these 2 organisms together occurred 53.4 times more frequently in the affected sheep than in the unaffected, which emphasises the probable multifactorial nature of the disease. The association between age and the presence of clinical signs was statistically significant. It was found that young sheep were more likely to have lesions than adult sheep. Clinical observations showed that the typical ulceration appears to be confined to the glans penis and lips of the vulva; no ulceration was observed on the shaft of the penis and prepuce or vaginal vestibule. In uncomplicated cases inflammation of the prepuce and vaginal vestibule is not a regular feature of the disease. Therefore the names ulcerative balanitis and vulvitis most accurately describe the nature of the disease in South Africa.

In vitro antimicrobial susceptibility of Mycoplasma mycoides mycoides large colony and Arcanobacterium pyogenes isolated from clinical cases of ulcerative balanitis and vulvitis in Dorper sheep in South Africa.

The in vitro activities of enrofloxacin, florfenicol, oxytetracycline and spiramycin were determined against field isolates of Mycoplasma mycoides mycoides large colony (MmmLC) by means of the broth microdilution technique. The minimum inhibitory concentrations (MICs) of these antimicrobial drugs were determined for a representative number of 10 isolates and 1 type strain. The susceptibility of Arcanobacterium pyogenes to enrofloxacin, oxytetracycline and tilmicosin was determined by means of an agar disk diffusion test. The MICs of enrofloxacin, florfenicol, oxytetracycline and spiramycin were within the ranges of 0.125-0.5, 1.0-2.0, 2.0-4.0 and 4.0-8.0 microg/ml, respectively. This study has shown that resistance of MmmLC against enrofloxacin, florfenicol, oxytetracycline and spiramycin was negligible. All the field strains of A. pyogenes that were tested were susceptible to enrofloxacin, oxytetracycline and tilmicosin with mean inhibition zones of 30.6, 42.3 and 35.8 mm, respectively. Although there is lack of data on in vivo efficacy and in vitro MIC or inhibition zone diameter breakpoints of these antimicrobial drugs for MmmLC, the MIC results indicate that these 4 classes of antimicrobial drugs should be effective in the treatment of ulcerative balanitis and vulvitis in sheep in South Africa.

Pain management in mice using the aqueous and ethanol extracts of four medicinal plants.

BACKGROUND: There are many traditionally used analgesic plants in Ethiopia. They, however, have not been subject to scientific investigation for their efficacy and safety. OBJECTIVE: To evaluate both prophylactic and relieving effects of aqueous and ethanol extracts of four traditionally used medicinal plants in Ethiopia. DESIGN: An experimental design in which five group of albino mice weighing 30-35 grams representing positive and negative control, and extract treated groups respectively. The extracts, standard drugs and normal saline were administered into GIT by gavage to evaluate the analgesic effect. SETTING: Department of Drug Research at Ethiopian Health and Nutrition Research Institute and Department of Pharmacology at Faculty of Medicine, Addis Ababa university. METHODS: Analgesic effects of water and ethanol extracts of four plants were evaluated against distilled water and standard analgesics (morphine and acetylsalicylic acid) with acetic acid induced writhing tests in mice. The four plants used for this screening were Ocimum sauve, Ocimum lamiifolium, Lippia adoensis and Ajuga remota. RESULTS: All extracts of the four plant materials were observed to possess both inhibiting and treatment activities against acetic acid induced pain. Dose related analgesic effect was also observed with all extracts of all plants with different potencies. Ethanol extracts of all the four plant materials were more potent than their water extracts at all dose levels except O. sauve, and L. adoensis whose water extracts seem to be a bit more potent at low dose. The analgesic potencies of both extracts of all the four plants were shown to be less than those of the standard analgesics. Of all the extracts, the ethanol extract of O. lamiifolium was found to be the most potent, while its water extract was the least. Acetic acid induced writhing was relieved with medium dose of both extracts in most cases and with low dose in few. Hundred percent relief was achieved with both standard analgesics at a very low dose. CONCLUSION: The present study show that all the extracts of all the plant materials have got both inhibiting and relieving effects of pain.

Multiplication of the V4 strain of Newcastle disease virus in Madin Derby bovine kidney cells.

This study describes a reproducible cell culture system that permits the growth and secondary multiplication of the V4 strain of Newcastle disease virus. Allantoic fluid, magnesium chloride and diethylaminoethyl dextran were incorporated in Dulbecco's modified Eagle's medium to encourage secondary viral multiplication without adversely affecting healthy Madin Derby bovine kidney cell growth.

Parasitological prevalence of bovine trypanosomosis in Kindo Koisha district, Wollaita zone, south Ethiopia.

A cross sectional survey to determine the distribution and prevalence of trypanosomosis was conducted in Kindo Koisha district, in the Wollaita zone in southern Ethiopia. A total of 1 008 adult cattle was examined at eight different localities. Dark field examination of the buffy coat, as well as stained thin blood film examination and packed cell volume (PCV) evaluation were the diagnostic techniques used. The overall prevalence of bovine trypanosomosis was 15 %. Among the positive animals, 108 (71.1%), 43 (28.4%) and 1 (0.6%) were due to Trypanosoma vivax, Trypanosoma congolense and mixed infection (T. vivax and T. congolense), respectively. The infection rate of T. vivax and T. congolense varied significantly (P < 0.01). The mean PCV of the positive and negative animals ranged between 18.3-32.1% and 26.8-33.4%, respectively. The mean PCV of negative animals (28 %) was significantly higher than the mean PCV of positive animals (22.3%) (P < 0.001). There was an inverse association of PCV with the prevalence of trypanosomosis (P > 0.05). The herd average PCV values of each site decreased with increasing proportion of the positive herds of that particular site. Of the diagnostic tests employed, the microhaematocrit buffy coat technique is relatively sensitive and it has an added advantage of indicating the general condition of the animal by haematocrit measurement. In view of the risk of trypanosomosis, a control intervention through the strategic application of appropriate trypanocidal drugs is recommended. A tsetse fly control scheme to reduce host-tsetse fly contact is equally as important as chemotherapy and chemoprophylaxis against trypanosomosis.

Theoretical perspectives for explaining infant mortality in the third world.

The authors analyze differentials in infant mortality rates in developing countries and attempt to go beyond the usual economic interpretations of these differences and identify some of the relevant social and political factors affecting infant mortality. In particular, they apply "a 'political economy of health' perspective to infant mortality and seek to account for discrepancies between economic progress and progress against infant mortality. [The paper] traces out a four-fold comparison--between countries with high/low economic development and countries with high/low infant mortality--for testing hypotheses in the political economy of health."