First report of probable neurobrucellosis in Australia.

We report the first known Australian case of probable neurobrucellosis, in a young feral-pig shooter who presented with episodic left-sided visual loss and left-sided numbness and headache. Treatment with intravenous ceftriaxone and oral rifampicin, doxycycline and trimethoprim­sulfamethoxazole resulted in a good clinical response.

Acute cardiac and neurologic decompensation in a high school athlete.

A 19-year-old African American man presented to a local emergency room with atrial flutter, dysarthria, and left-sided hemiparesis. He was previously healthy and a successful high school athlete. The patient decompensated and went into cardiac arrest. Two-dimensional echocardiography revealed biventricular dilation, severe systolic dysfunction, and a spongy myocardial appearance. Postmortem examination was diagnostic of biventricular noncompaction. Such a fulminant presentation of isolated ventricular noncompaction in a previously healthy and physically fit individual has not yet been described.

The cervical bruit: sound spectral analysis related to severity of carotid arterial disease.

Cervical bruits may signal the presence of high-grade narrowing of arterial supply to the brain. Previous small studies have suggested that severe arterial stenosis may produce bruits that persist longer and contain a greater proportion of higher-frequency sound spectral components. This study included 96 patients referred for duplex/Doppler testing after cervical bruits had been detected. With the use of a stethoscope equipped with wireless communication to an ordinary hand-held computer, we recorded these bruits, analyzed peak sound frequencies and the durations of sound persistence > or = 200 Hz, and correlated them with Doppler velocities. Overall, the durations and peak frequencies within the bruits correlated significantly with the peak Doppler derived velocities, that is, severity of arterial obstruction. In the presence of high-grade arterial stenosis (peak Doppler velocity > or = 200 cm/s), bruits regularly possessed either high peak frequencies or prolonged signal durations with a sensitivity approaching 90%. Bruits containing lower and nonsustained peak frequencies were uncommonly associated with severe arterial obstruction. Only well-transmitted bruits with frequencies reaching 200 Hz could be analyzed satisfactorily. In conclusion, we confirm earlier observations that peak frequencies and duration of arterial bruits correlate significantly with severity of underlying arterial obstruction. Equipment used is inexpensive, convenient, and portable. This method provides an objective means for confirming and quantifying subjective auditory impressions of bruits gained at the bedside. It can provide assistance in selecting patients for further testing and as a means for serial follow-up of individuals with known disease.

Distribution of 19 major virulence genes in Legionella pneumophila serogroup 1 isolates from patients and water in Queensland, Australia.

The distribution of 19 major virulence genes and the presence of plasmids were surveyed in 141 Legionella pneumophila serogroup (SG) 1 isolates from patients and water in Queensland, Australia. The results showed that 16 of the virulence genes examined were present in all isolates, suggesting that they are life-essential genes for isolates in the environment and host cells. The 65 kb pathogenicity island identified originally in strain Philadelphia-1(T) was detected more frequently in isolates from water (44.2%) than in those from patients (2.7%), indicating that the 65 kb DNA fragment may aid the survival of L. pneumophila in the sampled environment. However, the low frequency of the 65 kb fragment in isolates from patients suggests that the pathogenicity island may not be necessary for L. pneumophila to cause disease. Plasmids were not detected in the L. pneumophila SG1 isolates from patients or water studied. There was an association of both lvh and rtxA with the virulent and predominant genotype detected by amplified fragment length polymorphism, termed AF1, whereas the avirulent common isolate from water termed AF16 did not have lvh or rtxA genes, with the exception of one isolate with rtxA. It was found that a PCR detection test strategy with lvh and rtxA as pathogenesis markers would be useful for determining the infection potential of an isolate.

A predominant and virulent Legionella pneumophila serogroup 1 strain detected in isolates from patients and water in Queensland, Australia, by an amplified fragment length polymorphism protocol and virulence gene-based PCR assays.

In epidemiological investigations of community legionellosis outbreaks, knowledge of the prevalence, distribution, and clinical significance (virulence) of environmental Legionella isolates is crucial for interpretation of the molecular subtyping results. To obtain such information for Legionella pneumophila serogroup 1 isolates, we used the standardized amplified fragment length polymorphism (AFLP) protocol of the European Working Group on Legionella Infection to subtype L. pneumophila SG1 isolates obtained from patients and water sources in Queensland, Australia. An AFLP genotype, termed AF1, was predominant in isolates from both patients (40.5%) and water (49.0%). The second most common AFLP genotype found in water isolates was AF16 (36.5%), but this genotype was not identified in the patient isolates. When virulence gene-based PCR assays for lvh and rtxA genes were applied to the isolates from patients and water, nearly all (65 of 66) AF1 strains had both virulence genes, lvh and rtxA. In contrast, neither the lvh nor the rtxA gene was found in the AF16 strains, except for one isolate with the rtxA gene. It appears that this may explain the failure to find this genotype in the isolates from patients even though it may be common in the environment. In view of the evidence that the AF1 genotype is the most common genotype among strains found in patients and water sources in this region, any suggested epidemiological link derived from comparing the AF1 genotype from patient isolates with the AF1 genotype from environmental isolates must be interpreted and acted on with caution. The use of virulence gene-based PCR assays applied to environmental samples may be helpful in determining the infection potential of the isolates involved.

Epidemiology of invasive meningococcal disease in north Queensland, 1995 to 1999.

This study describes all episodes of invasive meningococcal disease (n=120) acquired in north Queensland over the 5 year period 1995 to 1999. Indigenous people had a 3-fold greater risk than others of acquiring invasive meningococcal disease. There were 7 deaths, six in non-indigenous people. The majority (72.4%) of identified isolates were serogroup B. We found no evidence of significant resistance to the antibiotics recommended for treatment or chemoprophylaxis. Two outbreaks of disease were identified, one serogroup B and one serogroup C. Compared to the previous 5 years (1990 to 1994) there were far fewer cases of serogroup C disease and a lower incidence and risk of invasive meningococcal disease among indigenous people.