The impact of pre-departure screening and treatment on notifications of malaria in refugees in south-east Queensland

This study aimed to investigate changes in the notification rate of malaria in refugees over a period of national policy change on pre-departure screening. Notifying clinicians were interviewed to complete a standardised enhanced surveillance form. A decline in refugee malaria notifications occurred after implementation of a national policy to offer pre-departure malaria screening and treatment as necessary to refugees. Surveillance data support the benefit of offering pre-departure screening and treatment as necessary to refugees.

An outbreak of shiga toxin-producing Escherichia coli infection associated with a school camp

In November 2008, a case of Shiga toxin-producing Escherichia coli (STEC) infection was reported to the Brisbane Southside Public Health Unit. The case had participated in a school camp. Subsequent investigations confirmed 5 other asymptomatic cases among camp attendees or visitors. Examination of the camp water supply identified that most water sources had high levels of E. coli and did not meet the Australian Drinking Water Guidelines with STEC isolated from 2 water sources. This outbreak highlights the emerging issue of asymptomatic carriage of STEC and the importance of thorough maintenance and attention to drinking water supplies in the rural and school camp setting.

An efficient high-throughput flow cytometric method for estimating DNA ploidy level in plants

We present an efficient high-throughput flow cytometric method that builds on previously published methods and permits rapid ploidy discrimination in plants. By using Brassica napus L. microspore-derived plants as an example, we describe how 192 leaf tissue samples may be processed and analyzed comfortably by one operator in 6 h from tissue sampling to ploidy determination. The technique involves placing young leaf samples in two 96-well racks, using a bead-beating procedure to release nuclei into a lysis solution, filtering the samples on 96-well filter plates, staining with propidium iodide, and then rapidly estimating DNA ploidy using a plate loader on a BD FACS-Canto II flow cytometer. Throughout the sample preparation process, multichannel pipetting allows faster and less error-prone sample handling. In two 96-well plates of samples, the histogram peaks of DNA content from flow cytometry were wellresolved in 189 of 192 samples tested (98.4%), with CV values ranging from 2.98% to 6.20% with an average CV of 4.35% (SD = 0.68%). This new method is useful in doubled haploid plant breeding programs where early discrimination of haploid and doubled haploid (i.e., diploid) plantlets can confer significantly improved operational efficiencies. We discuss how this method could be further refined including adapting the method to robotic sample processing.

Evaluation of clinical management of gonorrhoea using enhanced surveillance in South East Queensland

Background: Gonorrhoea is the second most common notifiable sexually transmissible infection (STI) in Queensland. Notifications have been increasing since 2002. Enhanced surveillance was undertaken in this study in order to evaluate clinical management and add to understanding of the epidemiology of gonorrhoea and in South East Queensland. Methods: Information on clinical management and an enhanced surveillance form were faxed to clinicians who notified gonorrhoea in the Brisbane Southside Population Health Unit area from 2003 to 2008. Ceftriaxone was recommended for treatment of gonorrhoea cases, as was simultaneous treatment for chlamydia, testing for other STIs and management of sexual contacts. Enhanced surveillance focussed on collecting more detailed epidemiological and clinical management information. Results: A total of 909 enhanced surveillance forms were returned (response rate 72.2%). The use of ceftriaxone increased significantly over the study period from 31.3% in 2003 to 68.4% in 2008 (P < 0.05). However, there remained a considerable proportion of cases that did not receive ceftriaxone (31.6% in 2008). Simultaneous treatment for chlamydia was reported for 70.5% of cases and did not increase over the study period. A high proportion of males were not screened for high risk co-infection such as HIV (49.6%) and syphilis (51.7%). Contact tracing was initiated for 76.5% of cases and did not increase during the study period. Conclusions: Continued education of clinicians on treatment guidelines is needed. Screening of other STIs such as HIV in males with gonorrhoea and increasing contact tracing were identified as aspects of clinical management for future improvement. Overall this study provides useful insights into the clinical management of gonorrhoea in South East Queensland.

“The dust hasn't settled yet”: the National Q fever Management Program, missed opportunities for vaccination and community exposures

AIMS

To determine the proportion of notifiable cases of Q fever attributable to occupational and community exposures and to identify missed opportunities for Q fever vaccination in notifications of occupational exposures.

METHODS

A review of Q fever notifications to the BSPHU from January 2000 to September 2006 was undertaken. Notifications were categorised according to probable exposure source. Occupational exposures were further categorised according to reported past exposure to Q fever and Q fever vaccination status.

RESULTS

One hundred and ninety-one Q fever notifications were identified, with occupational exposure reported in 106 cases and community exposure reported in 69 cases. In the occupational exposures, 76 cases (71%) were not vaccinated, 15 (14%) reported past exposure to Q fever and eight reported vaccination prior to illness onset, but vaccination status could not be independently verified. Community acquired Q fever was most commonly attributed to living or working near a high-risk industry (26, 38%), incidental exposures such as farm visits, or attending sale yards (27, 39%).

CONCLUSIONS

Occupationally acquired cases of Q fever continue to be reported in significant numbers and opportunities for vaccination are being missed. There is an ongoing need to ensure that all employees in high-risk industries are screened and vaccinated. The proportion of community acquired notifications of Q fever has increased since the National Q fever Management Program started, commensurate with the decline in occupationally acquired cases. These proportions may be expected to change with the cessation of the program in Queensland in December 2006.

An outbreak of multi-resistant Shigella sonnei in a long-stay geriatric nursing centre

An outbreak of Shigella sonnei infection in a long-stay nursing centre was detected during routine surveillance of notifications in July 1999. Subsequent investigations identified 13 cases of multi-resistant S. sonnei infection affecting nine staff, three community members associated with the centre and one resident of the centre. Each isolate of S. sonnei was genetically indistinguishable. The outbreak investigation identified contact with residents with vomiting and diarrhoea as a significant risk factor for infection amongst staff providing nursing care. This association, and the duration of the outbreak over several months, suggests that transmission was most likely person-to-person. This outbreak demonstrates the importance of infection control policies and hygiene measures in long-stay nursing facilities.

Potential exposure to Australian bat lyssavirus, Queensland, 1996-1999

Two human deaths caused by Australian bat lyssavirus (ABL) infection have been reported since 1996. Information was obtained from 205 persons (mostly adults from south Brisbane and the South Coast of Queensland), who reported potential ABL exposure to the Brisbane Southside Public Health Unit from November 1,1996, to January 31, 1999. Volunteer animal handlers accounted for 39% of potential exposures, their family members for 12%, professional animal handlers for 14%, community members who intentionally handled bats for 31%, and community members with contacts initiated by bats for 4%. The prevalence of Lyssavirus detected by fluorescent antibody test in 366 sick, injured, or orphaned bats from the area was 6%. Sequelae of exposure, including the requirement for expensive postexposure prophylaxis, may be reduced by educating bat handlers and the public of the risks involved in handling Australian bats.

Hepatitis A outbreaks among illicit drug users and their contacts in Queensland, 1997

OBJECTIVE

To describe five outbreaks of hepatitis A virus (HAV) infection associated with illicit drug use during a statewide outbreak of HAV infection in Queensland.

DESIGN

Risk factor prevalence survey.

PATIENTS AND SETTING

All 875 cases of HAV infection notified to Public Health Units in Queensland in the 12 months to 30 November 1997.

MAIN OUTCOME MEASURE

Type and prevalence of illicit drug use.

RESULTS

Risk factor assessment was completed for 804 cases (91.9%). We identified five outbreaks of HAV infection linked to illicit drug use. These outbreaks accounted for 24.6% (215/875) of all notified cases and 39% (190/482) of notified cases in the 15-34 years age group. The main type of illicit drug use in four of the five outbreaks was injecting drug use (74%; 118/160), while in the other outbreak it was sharing of smoking implements for marijuana (38%; 21/55).

CONCLUSION

Illicit drug use may be an under-recognised risk factor for HAV infection, particularly in young people. Faecal-oral transmission through poor personal hygiene, including sharing of implements for smoking marijuana, is the most probable route of transmission in these drug-linked outbreaks. The role of contaminated drug and needle-sharing remains to be clarified.

The role of glutaminase in the small intestine

Glutaminase is the enzyme which hydrolyses glutamine, the main respiratory fuel of the intestine, to yield glutamate and ammonia. Glutaminase has a central role in intestinal metabolism: the products of the reaction catalyzed by glutaminase can be transaminated, catabolized to yield energy or used for the biosynthesis of pyrimidine nucleotides. Experimental treatments which deprive the intestine of glutamine induce intestinal atrophy. In this review, attention is paid to the role of glutaminase in intestinal metabolism. Background information on the structure, kinetics and distribution of glutaminase precede a discussion of the metabolism of glutamine within the intestine. In closing, we review the factors known to regulate glutaminase activity and emphasise that the regulation of glutaminase within the intestine is poorly understood.

The role of enterocytes in gut dysfunction

Stem cells in the intestinal epithelium give rise to enterocytes, goblet cells, enteroendocrine cells, and Paneth cells. Each of these cell lines plays a role in cytoprotection of the intestinal mucosa. In particular, it has been demonstrated that mature enterocytes can act as antigen presenting cells. Parenteral and enteral nutrition are used to nourish critically ill patients. However, these regimens are unfortunately associated with gut atrophy. Glutamine, the preferred intestinal nutrient, reverses this gut atrophy and plays a key role in maintaining the barrier function of the gut. Specific nutrients (putrescine, spermidine, spermine) have been used to modulate intestinal adaption. In addition, ornithine has been shown to act as a regulator of intestinal adaption. In this review, we discuss the relationship between the biology of enterocytes and failure of the gut barrier.

Influence of ischaemia-reperfusion injury on CD44 expression in rat small intestine

BACKGROUND

CD44 is an adhesion molecule expressed by neutrophils and lymphocytes which is involved in cell-cell and cell-matrix binding. In this study, the effect of ischaemia-reperfusion injury on CD44 messenger RNA (mRNA) and cell surface immunohistochemical expression of CD44 in the rat small intestine was evaluated.

METHODS

Wistar rats (n=16) were randomized to either serve as controls (sham surgery) or to be subjected to a standardized ischaemia-reperfusion injury (suprarenal aorta occluded for 1 h followed by 1 h of reperfusion). Standardized segments of jejunum were harvested after ischaemia-reperfusion injury (ischaemic and reperfused samples) to measure the mucosal protein and DNA content, mRNA expression of CD44 and the immunohistochemical expression of CD44.

RESULTS

Reperfusion significantly damaged the jejunal mucosa, e.g. mucosal protein content was lower after reperfusion compared with that in the control group (z=-2.31, P=0.02) and the ischaemic samples (z=-2.52, P=001). The expression of cell surface CD44 protein was also significantly decreased after ischaemic injury (z=-1.99, P=0.04); this coincided with a decrease in the amount of cytoplasmic CD44 mRNA within isolated enterocytes (z=-2.31, P=0.02).

CONCLUSION

Ischaemia-reperfusion injury decreases the expression of CD44 within the jejunal mucosa. This may contribute to the failure of the gut barrier after such injury.

The influence of ischemia/reperfusion injury on the jejunum

Ischemia/reperfusion injury (IRI) after free tissue transfer of the small intestine results in transmural tissue damage. This study examined the effects of IRI on the jejunum. Wistar rats served either as controls (N=10) or underwent clamping of the infrarenal aorta for 1 hour followed by 1 hour of reperfusion (N=10). Both ischemia and reperfusion reduced the protein and deoxyribonucleic acid content of the jejunal mucosa (p < 0.05). Myeloperoxidase activity in the jejunal mucosa remained relatively low. The expression of leukocyte function-associated antigen 1 and intercellular adhesion molecule 1 (ICAM-1) on the surface of mucosal cells was not altered significantly by the ischemic insult, but was reduced after the period of reperfusion (p < 0.05). This coincided with an increase in messenger ribonucleic acid (mRNA) for ICAM-1 within isolated mucosal cells (p < 0.05). The specific activity of glutaminase in isolated jejunal mucosal cells was diminished after ischemia and reperfusion (p < 0.05), and this was not associated with an appreciable change in glutaminase mRNA expression. These results have identified some molecular mechanisms underlying IRI of the small intestine that are possible candidates for therapeutic intervention.

Loss of heterozygosity studies in squamous cell carcinomas of the head and neck

BACKGROUND

Loss of heterozygosity (LOH) studies have been pivotal in identifying tumor suppressor genes involved in the pathogenesis of a number of cancers. In squamous cell carcinomas of the head and neck region (SCCHN), LOH studies using the Southern blot technique are scarce.

METHODS

SCCHNs were obtained immediately after surgical resection from 78 patients. Histologic confirmation was made by frozen section and tumors with less than 50% malignant cells were excluded. DNA was digested with restriction enzymes, and after Southern blotting the membranes were hybridized with radio-labeled probes. Chromosome arms analyzed included 1p, 3p, 4p, Sq, 8p, lOp, 11p, 11q, 13q, 17p, 17q, 18q, 21q, and 22q.

RESULTS

The average rate LOH was 25% per chromosome arm. Significantly higher rates of LOH were observed for chromosome arms 5q (56%) and 17p (45%). Other investigators have reported high rates of LOH for the H- ras-1 locus, and chromosome arms 11p, 11q, and 13q. However, these results were not confirmed in this study. For patients with stage 1 or 2 tumors, the overall LOH rate was 13%, and for patients with stage 3 or 4 disease the rate was 23%. This difference was statistically significant (p < 0.025).

CONCLUSIONS

tumors progress to higher stages, they appear to accumulate an increasing number of genetic abnormalities. Chromosome arms 5q and 17p contain tumor suppressor genes which are likely to be involved in the pathogenesis of SCCHN:

Glutamine

Glutamine is the most abundant free amino acid in the circulation. It is a primary fuel for rapidly dividing cells and plays a key role in the transport of nitrogen between organs. Although glutamine is absent from conventional regimens aimed at nutritional support, glutamine deficiency can occur during periods of metabolic stress; this has led to the reclassification of glutamine as a conditionally essential amino acid. Experiments with various animal models have demonstrated that the provision of glutamine can result in better nitrogen homoeostasis, with conservation of skeletal muscle. There is also considerable evidence that glutamine can enhance the barrier function of the gut. This review concludes by discussing the clinical evidence that supports the inclusion of stable forms of glutamine in solutions of nutrients.