Optimizing outpatient serial sputum colony counting for studies of tuberculosis treatment in resource-poor settings.

Serial Sputum Colony Counting (SSCC) is an important technique in clinical trials of new treatments for tuberculosis (TB). Quantitative cultures on selective Middlebrook agar are used to calculate the rate of bacillary elimination from sputum collected from patients at different time points during the first 2 months of therapy. However, the procedure can be complicated by high sample contamination rates. This study, conducted in a resource-poor setting in Malawi, assessed the ability of different antifungal drugs in selective agar to reduce contamination. Overall, 229 samples were studied and 15% to 27% were contaminated. Fungal organisms were particularly implicated, and samples collected later in treatment were at particular risk (P < 0.001). Amphotericin B (AmB) is the standard antifungal drug used on SSCC plates at a concentration of 10 mg/ml. On selective Middlebrook 7H10 plates, AmB at 30 mg/ml reduced sample contamination by 17% compared with AmB at 10 mg/ml. The relative risk of contamination using AmB at 10 mg/ml was 1.79 (95% confidence interval [CI], 1.25 to 3.55). On Middlebrook 7H11 plates, a combination of AmB at 10 mg/ml and carbendazim at 50 mg/ml was associated with 10% less contamination than AmB at 30 mg/ml. The relative risk of contamination with AmB at 30 mg/ml was 1.79 (95% CI, 1.01 to 3.17). Improved antifungal activity was accompanied by a small reduction in bacillary counts, but this did not affect modeling of bacillary elimination. In conclusion, a combination of AmB and carbendazim optimized the antifungal activity of selective media for growth of TB. We recommend this method to reduce contamination rates and improve SSCC studies in African countries where the burden of TB is highest.

Sentinel lymph node biopsy in melanoma: The Oxford ten year clinical experience.

Sentinel lymph node biopsy (SLNB) has become an established investigation for assessing microscopic nodal metastasis in melanoma. The American Joint Committee on Cancer (AJCC) incorporates the sentinel node status in its staging criteria for melanoma. We present our clinical evaluation of performing SLNB in a single UK centre between 1998 and 2008. There were 697 patients with a mean age 53 years (range 13-92). We were able to surgically harvest at least one sentinel node in 694 patients of which 532 (76%) were negative. Of the 162 positive patients, 129 underwent further completion lymphadenectomy with 29 showing further pathologically positive nodes. At median follow up of 46 months, mortality from melanoma for SLN positive and negative patients was 32% and 4%, respectively. Disease recurrence was noted in 10% of the SLN negative group. Survival curves showed significant difference (p<0.001) in outcomes for patients grouped by Breslow thickness. Postoperative complications were noted in 6% of patients. No life-threatening complications were noted. Our results are comparable to other national and international studies. We await the outcomes of ongoing trials to assess the therapeutic value of SLNB for melanoma.

Towards Web-based representation and processing of health information.

BACKGROUND: There is great concern within health surveillance, on how to grapple with environmental degradation, rapid urbanization, population mobility and growth. The Internet has emerged as an efficient way to share health information, enabling users to access and understand data at their fingertips. Increasingly complex problems in the health field require increasingly sophisticated computer software, distributed computing power, and standardized data sharing. To address this need, Web-based mapping is now emerging as an important tool to enable health practitioners, policy makers, and the public to understand spatial health risks, population health trends and vulnerabilities. Today several web-based health applications generate dynamic maps; however, for people to fully interpret the maps they need data source description and the method used in the data analysis or statistical modeling. For the representation of health information through Web-mapping applications, there still lacks a standard format to accommodate all fixed (such as location) and variable (such as age, gender, health outcome, etc) indicators in the representation of health information. Furthermore, net-centric computing has not been adequately applied to support flexible health data processing and mapping online. RESULTS: The authors of this study designed a HEalth Representation XML (HERXML) schema that consists of the semantic (e.g., health activity description, the data sources description, the statistical methodology used for analysis), geometric, and cartographical representations of health data. A case study has been carried on the development of web application and services within the Canadian Geospatial Data Infrastructure (CGDI) framework for community health programs of the New Brunswick Lung Association. This study facilitated the online processing, mapping and sharing of health information, with the use of HERXML and Open Geospatial Consortium (OGC) services. It brought a new solution in better health data representation and initial exploration of the Web-based processing of health information. CONCLUSION: The designed HERXML has been proven to be an appropriate solution in supporting the Web representation of health information. It can be used by health practitioners, policy makers, and the public in disease etiology, health planning, health resource management, health promotion and health education. The utilization of Web-based processing services in this study provides a flexible way for users to select and use certain processing functions for health data processing and mapping via the Web. This research provides easy access to geospatial and health data in understanding the trends of diseases, and promotes the growth and enrichment of the CGDI in the public health sector.

Online GIS services for mapping and sharing disease information.

BACKGROUND: Disease data sharing is important for the collaborative preparation, response, and recovery stages of disease control. Disease phenomena are strongly associated with spatial and temporal factors. Web-based Geographical Information Systems provide a real-time and dynamic way to represent disease information on maps. However, data heterogeneities, integration, interoperability, and cartographical representation are still major challenges in the health geographic fields. These challenges cause barriers in extensively sharing health data and restrain the effectiveness in understanding and responding to disease outbreaks. To overcome these challenges in disease data mapping and sharing, the senior authors have designed an interoperable service oriented architecture based on Open Geospatial Consortium specifications to share the spatio-temporal disease information. RESULTS: A case study of infectious disease mapping across New Brunswick (Canada) and Maine (USA) was carried out to evaluate the proposed architecture, which uses standard Web Map Service, Styled Layer Descriptor and Web Map Context specifications. The case study shows the effectiveness of an infectious disease surveillance system and enables cross-border visualization, analysis, and sharing of infectious disease information through interactive maps and/or animation in collaboration with multiple partners via a distributed network. It enables data sharing and users' collaboration in an open and interactive manner. CONCLUSION: In this project, we develop a service oriented architecture for online disease mapping that is distributed, loosely coupled, and interoperable. An implementation of this architecture has been applied to the New Brunswick and Maine infectious disease studies. We have shown that the development of standard health services and spatial data infrastructure can enhance the efficiency and effectiveness of public health surveillance.

Three fatal cases of squamous cell carcinoma arising in chronic perineal hidradenitis suppurativa.

INTRODUCTION: Hidradenitis suppurativa (HS) is a chronic, inflammatory and suppurative disorder of skin bearing apocrine glands. The most severe complication is squamous cell carcinoma (SCC) and we here present three cases, all of which proved fatal, and review the past 40 years of published cases. PATIENTS AND METHODS: Three advanced cases of SCC arising in chronic HS have been referred for reconstructive surgery over the past 8 years. Another 28 cases published over the past 40 years were identified using a Medline search (search items in combination: hidradenitis, squamous, carcinoma). RESULTS: The male:female ratio was 4:1, most (61%) were perineal or buttock. We found no reports of SCC arising in axillary disease. The symptomatic history of HS prior to SCC diagnosis ranged from 3-50 years with a mean of 25 years. Age at diagnosis of SCC ranged from 27-71 years, and 15 patients (48%) died within 2 years of SCC diagnosis. CONCLUSIONS: We advocate that hidradenitis suppurativa arising in extra-axillary sites is a pre-malignant condition, and should not be treated conservatively; curative resection is the mainstay of management.

Augmentation of influenza surveillance with rapid antigen detection at the point-of-care: results of a pilot study in Tasmania, 2004.

Tasmania contributes very few laboratory confirmed cases to Australia's national influenza surveillance statistics. In 2004, a study was conducted to pilot test sentinel syndromic surveillance for influenza-like illness supplemented by point-of-care testing using the Binax Now Flu A Test Kit and by viral culture, to assess the feasibility and acceptability of this method of surveillance. Overall, the goal of such a system would be to increase laboratory surveillance activity within Tasmania and increase the number of specimens sent for viral culture. Five sites participated in the study, including three public hospital emergency departments and two general practices. Despite being conducted during a period of low influenza activity, the pilot study demonstrated that augmentation of syndromic surveillance with point-of-care testing is both feasible and acceptable but is best conducted in the general practice setting.

Meningococcal vaccine failure in conjunction with an unusual meningococcal cluster in southern Tasmania.

The following is a report of an unusual family cluster of group C invasive meningococcal disease in Tasmania. This unusual case cluster raises several important issues of public health significance regarding vaccine failure and nucleic acid amplification testing use in the setting of invasive meningococcal disease.

A multi-jurisdictional outbreak of hepatitis A related to a youth camp--implications for catering operations and mass gatherings.

In June 2003, Australian state and territory health departments were notified of an outbreak of Hepatitis A in people who had attended a five-day youth camp. Approximately 350 people attended the event in Central Australia between 24 and 28 April 2003. The public health investigation comprised of case identification, food handler interviews, an environmental health investigation of the campground and associated food premises, laboratory analysis of blood specimens and food/water samples, and an epidemiological study. Twenty-one cases fitted the case definition for the outbreak. A retrospective cohort study involving four states was conducted, with 213 people interviewed. Coleslaw and cordial were significantly associated with illness, however when the two exposures were adjusted for each other to account for confounding, only coleslaw remained significantly associated with illness (adjusted RR 2.5, 95% CI 1.09 - 5.77). The investigation highlighted a number of food hygiene and safety issues relating to the catering of mass gatherings. Implementation of food safety programs in these settings are likely to reduce the occurrence of such outbreaks. The recent proposal by Food Standards Australia New Zealand to mandate food safety programs for catering operations is supported.

An outbreak of cryptosporidiosis associated with an animal nursery at a regional fair.

Cryptosporidiosis is a common gastrointestinal illness that is transmitted from infected persons, animals, or contaminated water or food. This article reports on an outbreak of cryptosporidiosis associated with an animal nursery at an agricultural show held in northern Tasmania during October 2001. Eighty-one per cent of cases (38/47) notified to the Tasmanian Department of Health and Human Services over a 35 day period were interviewed to determine potential sources of infection. Eighty-one per cent of interviewed cases (29/36) reported that they had attended the agricultural show, and 75 per cent (27/36) reported contact with animals in the animal nursery. Cases occurring more than one incubation period after the agricultural show were significantly more likely to have had contact with someone else with diarrhoea (p<0.01). This is the first reported outbreak of cryptosporidiosis associated with an animal nursery in Australia. The outbreak demonstrates the importance of infection control policies and hygiene measures in the animal nursery setting.