A serological study of leptospirosis in domestic deer in New Zealand

Extract

Rape (Brassica napus) is grown in New Zealand predominantly for fattening lambs after weaning⁽¹⁾, although its use has steadily declined, especially in the North Island. One of the important precautions to be taken when using rape for supplementary feeding is that it must be mature before feeding. Rape grazed in the immature stage, before it takes on a purple tinge, can induce photosensitisation (rape scald)⁽²⁾.     

A serological study of bovine leptospirosis in the district of Taranaki

A cross-sectional serological survey of dairy cattle in Taranaki in 1979-80 indicated that 62% (551/891) of the animals had evidence of Leptospira interrogans serovar hardjo infection as disclosed by the microscopic agglutination test. Titres to Leptospira interrogans serovar pomona were demonstrated in only 4% (23/591) of the animals examined. The high prevalence of hardjo infection is suggestive of an endemic infection whilst the low level to pomona is indicative of sporadic infection. In a detailed examination of 10 herds, 9 revealed high (55%-91%) prevalence of serological reactions to hardjo and the herd profiles of titres, indicated that the animals had become infected at one to two years of age. A field strain of hardjo from cattle as well as the usual laboratory strain (hardjoprajitno) was incorporated in the test but there were no significant differences between the results given by the two antigens.     

A serological survey of leptospirosis in cats

A serological survey of 225 cats from different parts of the NorthIsland was conducted using 11 leptospiral serovar antigens. Twenty (8.8%) of the sera gave titres to the microagglutination test.The prevalence of titres to the serovars were as follows: five (2.22%) to copenhageni, five (2.22%) to hardjo, four (1.77%) to ballum, four (1.77%) to pomona, one (0.44%) to balanica and one (0.44%) to canicola; no titres to tarassovi, bataviae, pyrogenes and australis were recorded. It is hypothesised that prey-predator transmission between cats and rodents is responsible for infections with serovars copenhageni and ballum. Infections with the other serovars are presumed to result from contact with infected animals or a contaminated environment.     

A serological survey of canine respiratory coronavirus in New Zealand

ABSTRACT

Aims: To determine the seroprevalence of canine respiratory coronavirus (CRCoV) in New Zealand dogs, and to explore associations with age, sex, breed, month, and geographical region of sampling and reported presence of clinical signs suggestive of respiratory disease.

Methods: A total of 1,015 canine serum samples were randomly selected from submissions to a diagnostic laboratory between March and December 2014, and were analysed for CRCoV antibodies using a competitive ELISA. Logistic regression analysis was used to determine associations between seroprevalence of CRCoV and breed category, age, sex, sampling month, region, and reported health status of dogs.

Results: Overall, 538/1,015 (53.0%) samples were seropositive for CRCoV, with 492/921 (53.4%) positive dogs in the North Island and 46/94 (49%) in the South Island. Age of dog, sampling month, region, and presence of abnormal respiratory signs were included in the initial logistic regression model. Seroprevalence was higher in dogs aged ≥3 compared with ≤2 years (p?<?0.01). The lowest seroprevalence was observed in July (30/105; 28.5%) and August (32/100; 32%), and the highest in June (74/100; 74%). Seroprevalence in dogs from Auckland was higher than in dogs from the Hawkes Bay, Manawatu, Marlborough, and Waikato regions (p?<?0.05). Abnormal respiratory signs (coughing, nasal discharge, or sneezing) were reported for 28/1,015 (2.8%) dogs sampled. Seroprevalence for CRCoV tended to be higher among dogs with respiratory signs (67.9 (95% CI?=?47.6–83.4)%) than dogs with no reported respiratory signs (52.6 (95% CI?=?49.5–55.7)%).

Conclusions: Serological evidence of infection with CRCoV was present in more than half of the dogs tested from throughout New Zealand. Differences in CRCoV seroprevalence between regions and lack of seasonal pattern indicate that factors other than external temperatures may be important in the epidemiology of CRCoV in New Zealand.

Clinical relevance: Our data suggest that CRCoV should be included in investigations of cases of infectious canine tracheobronchitis, particularly if these occur among dogs vaccinated with current vaccines, which do not include CRCoV antigens.     

A serological survey for equine influenza in New Zealand horses

Sheep and alpacas of similar age groups (6, 18 and 36+ months) were grazed for 16 weeks on pasture contaminated by lambs. Faecal egg counts, bulked larval cultures, lungworm larvae in faeces, dag scores, liveweight changes and nematode larvae on pasture were measured. Chabertia, Oesophagostomum, Cooperia, Ostertagia and Haemonchus and Trichostrongylus larvae were cultured from both the sheep and the alpacas. For the respective age groups, the alpacas had lower liveweight gains (10, 32 and 47 g/d vs 88, 84 and 120 g/d), peak faecal egg counts (384, 50 and 60 epg vs 1500, 500 and 140 epg) and faecal contamination of the perineum than the same ages of sheep. These results suggest alpacas became less affected with gastrointestinal nematodes than sheep.     

Observations of leptospirosis in farmed deer

AIMS: Slaughterhouse and on-farm surveys were undertaken to investigate some aspects of leptospirosis (Leptospira interrogans) in farmed deer in the lower North Island of New Zealand. METHODS: Blood samples and kidneys were collected at slaughter from 601 l-year and older red and red X Wapiti stags and 21 adult hinds from 53 farms (10 or 12 deer per farm). Serum samples were analysed for up to seven Leptospiral serovars. Gross and histological examinations of kidneys were undertaken. Kidneys from 202 deer were cultured for leptospires. A follow-up postal questionnaire (68% response) indicated one herd had been vaccinated prior to the survey. Serological analyses were also carried out on serum bank samples from a previous on-farm survey involving male and female weaner, yearling and adult red deer from 16 commercial deer farms in March and November. RESULTS: Serological reactions at titres > or = 96 to serovar hardjo were present in 73.6%, pomona in 41.5%, copenhageni in 11.3% and tarassovi in 15.1% of farms from the slaughterhouse survey. Antibodies to serovars australis, ballam and balanica were present in three, one and four of six herds studied, respectively. Titre prevalence to hardjo was higher than that of pomona and other serovars within farms. Cultures for Leptospira were positive in 10 stags from six lines with similar prevalence across age groups. Histological examination showed many gross lesions were associated with mild interstitial cellular infiltration characteristic of subclinical Leptospiral infections. Some sections from culture-positive kidneys contained spirochetes in renal tubules. The on-farm survey showed a 10-30% within-herd prevalence of pomona and hardjo titres in 56% of 3-month-old deer herds, but by 11 months of age, 100% of herds were titre-positive with high prevalences to one or both serovars. Concurrently, herds of 1-year-old and adult deer on the same farms were all seropositive. CONCLUSION: This study has shown that Leptospiral infections are common in farmed deer in the survey area.     

A microbiological and serological study of leptospirosis among pigs in the Morogoro municipality,Tanzania

Serological and microbiological studies on leptospirosis in pigs from Morogoro municipality, Tanzania were carried out between October 2007 and May 2008. Serum samples (n = 385) from apparently healthy pigs were tested by microscopic agglutination test for antibodies against live cultures of six known Leptospira interrogans serovars: Pomona, Icterohaemorrhagiae, Ballum, Tarassovi, Grippotyphosa and Hardjo. Significant positive titres were detected in 4.42% (17/385) of all the tested serum samples. Asceptically collected samples, urine (n = 236) and kidney tissues (n = 214), were cultured in enriched Fletcher’s and Ellinghausen McCullough–Johnson and Harris media and assessed, at weekly intervals for 24 weeks, for growth by dark-field microscopy. Two leptospiral organisms were isolated from the urine samples. There was a statistical association between seroposivity and location that the subjects reside in (P < 0.05), whereas it was not significantly associated with sex nor age (P > 0.05). The evidence of pig exposure to different serovars and the isolation of the leptospiral organisms confirm that the infection is present in pigs although with an overall low prevalence. Apart from its economic importance on to the pig industry, this disease is a potential zoonotic public health risk in Tanzania, especially because of the lack of studies on leptospirosis among persons who handle pigs and pork products.     

Yersiniosis in deer from the Otago-Southland region of New Zealand

Samples from 350 routine deer cases submitted to Invermay Animal Health Laboratory for diagnosis during 1979–1982 were examined specifically for the presence of Yersinia sp. An analysis of 57 cases of yersiniosis due to Yersinia pseudotuberculosis is made and two cases due to Yersinia enterocolitica are described. The occurrence of cases appeared strongly correlated with periods of stress, predominantlyin winter when cool wet conditions and lack of grazing combined to precipitate the disease. Animals up to one year old were most commonly affected (64% of cases). Of the 61 strains of Yersinia pseudotuberculosis isolated 35 were of Serotype I, 17 of Serotype II and nine of Serotype III. All strains of Yersinia pseudotuberculosis and the strains of Yersinia enterocolitica isolated from the two cases described were Hela cell invasive and gave a positive autoagglutination test for virulence.     

Capillariasis in the domestic fowl in New Zealand

Abstract

Extract

With the increase in more intensive methods of poultry production in recent years, worms of the genus Capillaria Zeder 1800 (hairworms) have become an important factor contributing to disease in chickens and turkeys. Apart from causing death, they are also responsible for lower growth rates, decreased egg production, and decreased fertility of the flock (Platt and Schwabe, 1958 Platt, C. S. and Schwabe, O. 1958. A notation on the egg production and mortality of pullets free of capillary worms. Poultry Sci., 37: 727–727.  [Google Scholar]; Geevaerts, 1962 Geevaerts, J. 1962. Bestrying van capillariose bij driven en kippern door methyridine. Vlaam. Diergeneesk. Tijschr., 31: 105–113.  [Google Scholar]; Norton and Joyner, 1965 Norton, C. C. and Joyner, L. P. 1965. Experimental chemotherapy of infection with Capillaria obsignata. J. comp. Path., 75: 137–145. [Crossref] , [Google Scholar]; Wakelin, 1965 Wakelin, D. 1965. A survey of the intestinal helminthes parasitic in the British domestic fowl. J. Helminth., 112: 191–200.  [Google Scholar]), Unfortunately, these parasites have been relatively neglected in research and survey work. Far more interest has been devoted to the more obvious nematode parasites of poultry, such as Ascaridia galli and Heterakis gallinarum. This can, in part, be explained by the facts that Capillaria spp. are difficult to work with, they are not easily detectable and infections are difficult to establish under experimental conditions.     

Yersiniosis in deer from the Otago-Southland region of New Zealand

Samples from 350 routine deer cases submitted to Invermay Animal Health Laboratory for diagnosis during 1979-1982 were examined specifically for the presence of Yersinia sp. An analysis of 57 cases of yersiniosis due to Yersinia pseudotuberculosis is made and two cases due to Yersinia enterocolitica are described. The occurrence of cases appeared strongly correlated with periods of stress, predominantly in winter when cool wet conditions and lack of grazing combined to precipitate the disease. Animals up to one year old were most commonly affected (64% of cases). Of the 61 strains of Yersinia pseudotuberculosis isolated 35 were of Serotype I, 17 of Serotype II and nine of Serotype III. All strains of Yersinia pseudotuberculosis and the strains of Yersinia enterocolitica isolated from the two cases described were Hela cell invasive and gave a positive autoagglutination test for virulence.     

Leptospirosis in farmed deer in New Zealand : a review

Current knowledge of leptospirosis in farmed deer in New Zealand is reviewed. Over the past 25 years, leptospirosis has been reported to occur in individual cases as well as in herd outbreaks in farmed deer and in human cases linked to farmed deer. Serological studies and evidence from bacterial culture suggest infection is widespread. Mixing of young stock from several sources appears to be a significant risk factor for outbreaks. The culture of Leptospira interrogans serovars Hardjobovis, Pomona and Copenhageni has been reported. Infection with serovar Hardjobovis had the highest prevalence, either individually or mixed with serovar Pomona. Infection with serovar Copenhageni appears uncommon and its pathogenicity in deer is unproven. Titres to serovars Australis, Ballum, Balcanica and Tarassovi have been reported. Deer appear to be maintenance hosts for serovar Hardjobovis, incidental or accidental hosts and probably a maintenance population for serovar Pomona, since some infections persist for several months, and accidental hosts for serovar Copenhageni. Serovar Pomona appears to produce clinical and probably subclinical disease, whereas serovar Hardjobovis appears to cause only subclinical disease, although the relative risk of disease causation has not been determined. Clinical disease is usually manifested by haemolysis, jaundice, renal lesions, haemoglobinuria and often by sudden death. Renal lesions are commonly observed at slaughter and many are associated with leptospiral infections. Occupationally, slaughterhouse workers appear to be at greatest risk of contracting the disease from deer. Vaccination produces serological responses, but its effectiveness in protecting against disease, and prevention or reduction of shedding in urine, has not yet been confirmed in deer. More robust knowledge of the epidemiology of leptospiral infections in deer, and the effectiveness of vaccines and vaccination regimes, is needed to assist the deer industry to develop a strategy to manage this disease.