Prevalence of Mycobacterium avium subsp. paratuberculosis fecal shedding in alpacas presented to veterinary hospitals in the United States.

BACKGROUND: The prevalence of Johne's disease in alpacas in the United States is unknown. The limits of polymerase chain reaction (PCR) detection of Mycobacterium avium subsp. paratuberculosis (MAP) in alpaca feces have not been determined. OBJECTIVES: To evaluate the use of PCR for MAP detection in alpaca feces; and to estimate the prevalence of MAP fecal shedding in alpacas presented to veterinary teaching hospitals. ANIMALS: Alpacas presenting to 4 US veterinary teaching hospitals from November 2009 to February 2011. METHODS: Prospective study. Ten dilutions of a wild MAP strain were added to negative alpaca feces and processed for MAP detection by means of a commercial real-time PCR (RT-PCR) assay, and cultured on Herrold's Egg Yolk Medium (HEYM) and liquid broth. The limits of detection for each method were determined. Fecal samples from alpacas admitted to the veterinary teaching hospitals during the study period were evaluated for MAP via PCR and HEYM. RESULTS: The lowest MAP dilution detectable via PCR was 243 MAP colony-forming units (CFU)/g of feces, at which concentration MAP growth was detectable on HEYM. Ten (6%; 95% confidence interval: 3-9%) of the 180 fecal samples collected were positive on PCR. CONCLUSIONS AND CLINICAL IMPORTANCE: Polymerase chain reaction can provide an accurate and rapid detection of MAP fecal shedding in alpacas; and the prevalence of MAP fecal shedding in hospitalized alpacas in 4 US veterinary teaching hospitals was 6%.

Coronary artery trauma in chest wall injury.

BACKGROUND: Blunt chest trauma is a rare but important cause of coronary artery occlusion. Coronary damage may occur with even relatively minor chest injuries. The diagnosis of cardiac injury can be difficult in the setting of chest wall trauma as the usual findings of chest pain, cardiac enzyme assay and ECG are unreliable diagnostic tools. OBJECTIVE: A case is presented demonstrating the diagnosis difficulties. DISCUSSION: An ECG abnormality in the setting of even minor chest injury requires assessment with echocardiography and, if abnormal, angiography. Currently angiography is the definitive diagnostic test and allows for therapeutic intervention as appropriate but coronary artery ultrasound may find a place in management. Further management depends on the time of diagnosis and the presence of other injuries.

Eosinophilic meningitis. An unusual cause of headache.

Human parasitic infections are uncommon outside the tropical north but common in animals throughout Australia. The rat lung worm, Angiostrongylus cantonensis, can invade the human brain to cause a chronic meningitis with prolonged headache. This condition can be diagnosed by finding a high eosinophil count in cerebrospinal fluid (CFS), the lumbar puncture also provides symptomatic relief. The outcome is usually benign but death has been reported.

Leptospirosis in the Seychelles.

OBJECTIVE: To ascertain the incidence of leptospirosis in the Seychelles, identify its sources, review diagnostic features and assess complications. DESIGN: A prospective survey over a two-year period 1988-1990 of all cases diagnosed as having leptospirosis at Victoria Hospital, the main referral hospital for the Islands. RESULTS: Eighty cases were diagnosed on clinical grounds with serological confirmation in 58 (73%). Leptospira interrogans serovar icterohaemorrhagiae was identified in 27 (33%) and serovar autumnalis in 2 (3%), there was broad cross-reactivity in the other specimens. In a further 7 (9%), the diagnosis was confirmed at autopsy. Useful diagnostic aids were the finding of myalgia in 68 (85%) and a raised creatine phosphokinase (CPK) level in 61 (76%). CPK elevation was found to be a more reliable indicator of disease the earlier in the illness it was measured. Other important clinical signs are reviewed. Sixty (76%) were regular drinkers suggesting a relationship with home-brewed alcohol, 48 (60%) were in at-risk occupations; 13 (16%) deaths resulted. CONCLUSIONS: Leptospirosis in the Seychelles is likely to be rat borne. An annual incidence of 60 per 100,000 was found with significant mortality. Muscle tenderness and raised CPK levels were the most reliable early diagnostic aids.

A histological and serological study of persistent hepatitis B antigenaemia.

A population of persistent hepatitis B antigen positive persons was investigated in north Taranaki. Over a period of three years, 0.17 percent of blood donors and 7.7 percent of patients investigated for acute infection, possibly hepatitis, had a positive test for hepatitis B surface antigen (HBsAg). Repeat testing was performed at approximately four months in 65 persons and 18 (28 percent) remained positive and of these 15 were males. Liver biopsy in 17 of these patients revealed chronic persistent hepatitis in 30 percent, non-specific changes in 11 percent and in the remainder no significant abnormalities were found. There was no correlation of histology with a wide variety of hepatitis B serological markers. Forty-seven percent of the persistent carriers were Maoris and this group may be more susceptible to chronic hepatitis B infection. Long term follow up of HBsAg carriers is recommended to ascertain the prognosis of this condition.