Katherine B. Gibney

Vitamin D Deficiency Is Associated with Tuberculosis and Latent Tuberculosis Infection in Immigrants from Sub-Saharan Africa

Among African immigrants in Melbourne, Victoria, Australia, we demonstrated lower geometric mean vitamin D levels in immigrants with latent tuberculosis infection than in those with no Mycobacterium tuberculosis infection (P=.007); such levels were also lower in immigrants with tuberculosis or past tuberculosis than in those with latent tuberculosis infection (P=.001). Higher vitamin D levels were associated with lower probability of any M. tuberculosis infection (P=.001) and lower probability of tuberculosis or past tuberculosis (compared with latent tuberculosis infection; P=.001).

The global burden of dengue: an analysis from the Global Burden of Disease Study 2013

BACKGROUND Dengue is the most common arbovirus infection globally, but its burden is poorly quantified. We estimated dengue mortality, incidence, and burden for the Global Burden of Disease Study 2013. METHODS We modelled mortality from vital registration, verbal autopsy, and surveillance data using the Cause of Death Ensemble Modelling tool. We modelled incidence from officially reported cases, and adjusted our raw estimates for under-reporting based on published estimates of expansion factors. In total, we had 1780 country-years of mortality data from 130 countries, 1636 country-years of dengue case reports from 76 countries, and expansion factor estimates for 14 countries. FINDINGS We estimated an average of 9221 dengue deaths per year between 1990 and 2013, increasing from a low of 8277 (95% uncertainty estimate 5353-10 649) in 1992, to a peak of 11 302 (6790-13 722) in 2010. This yielded a total of 576 900 (330 000-701 200) years of life lost to premature mortality attributable to dengue in 2013. The incidence of dengue increased greatly between 1990 and 2013, with the number of cases more than doubling every decade, from 8·3 million (3·3 million-17·2 million) apparent cases in 1990, to 58·4 million (23·6 million-121·9 million) apparent cases in 2013. When accounting for disability from moderate and severe acute dengue, and post-dengue chronic fatigue, 566 000 (186 000-1 415 000) years lived with disability were attributable to dengue in 2013. Considering fatal and non-fatal outcomes together, dengue was responsible for 1·14 million (0·73 million-1·98 million) disability-adjusted life-years in 2013. INTERPRETATION Although lower than other estimates, our results offer more evidence that the true symptomatic incidence of dengue probably falls within the commonly cited range of 50 million to 100 million cases per year. Our mortality estimates are lower than those presented elsewhere and should be considered in light of the totality of evidence suggesting that dengue mortality might, in fact, be substantially higher. FUNDING Bill & Melinda Gates Foundation.

Cutaneous Melioidosis in the Tropical Top End of Australia: A Prospective Study and Review of the Literature

BACKGROUND Burkholderia pseudomallei is endemic in northern Australia, and melioidosis is a common cause of sepsis in the region. METHODS We summarized the cutaneous manifestations of melioidosis from a prospective cohort of 486 patients with culture-confirmed melioidosis in northern Australia, and we compared those who had primary skin melioidosis with those who had other forms of melioidosis. RESULTS Primary skin melioidosis occurred in 58 patients (12%). Secondary skin melioidosis--multiple pustules from hematogenous spread--was present in 10 patients (2%). Patients with primary skin melioidosis were more likely to have chronic presentations (duration, >or=2 months). On multivariate analysis, patients with primary cutaneous melioidosis were more likely to be children aged <or=15 years (adjusted odds ratio, 8.50; 95% confidence interval [CI], 3.24-22.28) and to have a history of occupational exposure to B. pseudomallei (adjusted odds ratio, 3.12; 95% CI, 1.56-6.25) but were less likely to have typical risk factors--including diabetes (adjusted odds ratio, 0.26; 95% CI, 0.12-0.56), excessive alcohol intake (adjusted odds ratio, 0.45; 95% CI, 0.22-0.90), and chronic lung disease (adjusted odds ratio, 0.26; 95% CI, 0.10-0.67). Of those patients with primary skin melioidosis, 1 patient was bacteremic and none had severe sepsis or died from melioidosis. Four (7%) of the 58 patients presenting with primary skin melioidosis had disseminated melioidosis, and 1 (2%) experienced a relapse of melioidosis. Nine patients (16%) were cured with a regimen of oral antibiotics alone, and 1 recovered with no therapy. CONCLUSION In our cohort, patients with primary skin melioidosis were younger, had fewer underlying medical conditions, and had better outcomes than did those with other forms of melioidosis. There may be a role for exclusive oral antibiotic therapy for some cases of primary skin melioidosis.

Disease burden of selected gastrointestinal pathogens in Australia, 2010.

OBJECTIVE To estimate and compare disease burden attributable to six gastrointestinal pathogens (norovirus, rotavirus, Campylobacter, non-typhoidal Salmonella, Giardia, and Cryptosporidium) in Australia, 2010. METHODS We estimated the number of acute gastroenteritis (AGE) cases and deaths, disability-adjusted life years (DALYs), and DALY/case for each pathogen. We included AGE cases that did not require medical care. Sequelae were included for Campylobacter (Guillain-Barré syndrome, reactive arthritis (ReA), irritable bowel syndrome (IBS)) and Salmonella (ReA, IBS). RESULTS We estimated 16626069 AGE cases in Australia in 2010 (population 22 million). Of the pathogens studied, most AGE cases were attributed to norovirus (2180145), Campylobacter (774003), and Giardia (614740). Salmonella caused the fewest AGE cases (71255) but the most AGE deaths (90). The DALY burden was greatest for Campylobacter (18222 DALYs) and Salmonella (3856 DALYs), followed by the viral and protozoal pathogens. The average DALY/case was greatest for Salmonella (54.1 DALY/1000 cases), followed by Campylobacter (23.5 DALY/1000 cases). CONCLUSIONS The pathogen causing the greatest disease burden varied according to the metric used, however DALYs are considered most useful given the incorporation of morbidity, mortality, and sequelae. These results can be used to prioritize public health interventions toward Salmonella and Campylobacter infections and to measure the impact of these interventions.

Isolated core antibody hepatitis B in sub‐Saharan African immigrants

Chronic hepatitis B virus (HBV) infection is a major health problem in sub‐Saharan Africa, where prevalence is ≥8%, and is increasingly seen in African immigrants to developed countries. A retrospective audit of the medical records of 383 immigrants from sub‐Saharan Africa attending the infectious diseases clinics at the Royal Melbourne Hospital was performed from 2003 to 2006. The HBV, human immunodeficiency virus (HIV) and hepatitis C virus (HCV) serological results are reported, with a focus on the isolated core antibody HBV pattern (detection of anti‐HBc without detection of HBsAg or anti‐HBs). Two‐thirds (118/174, 68%) of those tested had evidence of HBV infection with detectable anti‐HBc. Chronic HBV infection (serum HBsAg detected) was identified in 38/174 (22%) and resolved HBV infection (both serum anti‐HBs and anti‐HBc detected) in 45/174 (26%). The isolated core antibody pattern was identified in 35/174 (20%), of whom only 1/35 (3%) had detectable serum HBV DNA on PCR testing, indicating occult chronic HBV (OCHB). Only 8/56 (14%) patients with negative anti‐HBc had serological evidence of vaccination (serum anti‐HBs detected). HIV infection was detected in 26/223 (12%). HCV antibodies were detected in 10/241 (4%), of whom 8 (80%) had detectable HCV RNA. Viral co‐infection was detected in only 2/131 (1.5%) patients tested for all three viruses. The isolated core antibody HBV pattern was common among sub‐Saharan African patients in our study. These patients require assessment for OCHB infection and monitoring for complications of HBV. J. Med. Virol. 80:1565–1569, 2008.

Screening Practices for Infectious Diseases among Burmese Refugees in Australia

Helicobacter pylori and Strongyloides spp. infections were the most common conditions found.

Modifiable Risk Factors for West Nile Virus Infection during an Outbreak—Arizona, 2010

West Nile virus (WNV) is the leading cause of mosquito-borne disease in the United States; however, risk factors for infection are poorly defined. We performed a case-control study to identify modifiable risk factors for WNV infection. Case-patients (N = 49) had laboratory evidence of recent WNV infection, whereas control-subjects (N = 74) had negative WNV serology. We interviewed participants, surveyed households, and assessed environmental data. WNV infection was associated with living in or near Water District X within Gilbert Township (adjusted odds ratio [aOR] 5.2; 95% confidence interval [95% CI] = 1.5-18.1), having water-holding containers in their yard (aOR 5.0; 95% CI = 1.5-17.3), and not working or attending school outside the home (aOR 2.4; 95% CI = 1.1-5.5). During this outbreak, WNV infection was likely primarily acquired peri-domestically with increased risk associated with potential mosquito larval habitats around the home and neighborhood.

Using disability-adjusted life years to set health-based targets: a novel use of an established burden of disease metric.

Following the 1990 Global Burden of Disease (GBD) study, Disability-Adjusted Life Years (DALYs) have been used widely to quantify the population health burden of diseases and to prioritise and evaluate the impact of specific public health interventions. In the context of the recent release of the 2010 GBD study, we explore the novel use of DALYS to determine health-based targets (HBTs). As with the more traditional use of DALYs, the main advantage of using DALYs as HBTs is the ability to account for differential disease severity, identify the most appropriate public health interventions, and measure the positive and negative outcomes of these interventions. Australia is currently considering adopting DALYs for setting HBTs for drinking water quality, as recommended by the WHO. Adoption of DALY HBTs could be relevant in other areas, including air quality, food safety, health care-associated infections, and surgical complications.

Evolution of regulatory targets for drinking water quality

The last century has been marked by major advances in the understanding of microbial disease risks from water supplies and significant changes in expectations of drinking water safety. The focus of drinking water quality regulation has moved progressively from simple prevention of detectable waterborne outbreaks towards adoption of health-based targets that aim to reduce infection and disease to a level well below detection limits at the community level. This review outlines the changes in understanding of community disease and waterborne risks that prompted development of these targets, and also describes their underlying assumptions and current context. Issues regarding the appropriateness of selected target values, and how continuing changes in knowledge and practice may influence their evolution, are also discussed.

Educating international students about tuberculosis and infections associated with travel to visit friends and relatives (VFR-travel)

BACKGROUND International students in Victoria, Australia, originate from over 140 different countries. They are over-represented in disease notifications for tuberculosis and travel-associated infections, including enteric fever, hepatitis A, and malaria. We describe a public health initiative aimed to increase awareness of these illnesses among international students and their support staff. METHODS We identified key agencies including student support advisors, medical practitioners, health insurers, and government and professional organisations. We developed health education materials targeting international students regarding tuberculosis and travel-related infections to be disseminated via a number of different media, including electronic and printed materials. We sought informal feedback from personnel in all interested agencies regarding the materials developed, their willingness to deliver these materials to international students, and their preferred media for disseminating these materials. RESULTS Education institutions with dedicated international student support staff and on-campus health clinics were more easily engaged to provide feedback and disseminate the health education materials than institutions without such dedicated personnel. Response to contacting off-campus medical practices was poor. Delivery of educational materials via electronic and social media was preferred over face-to-face education. CONCLUSIONS It is feasible to provide health education messages targeting international students for dissemination via appropriately-staffed educational institutions. This initiative could be expanded in terms of age-group, geographic range, and health issues to be targeted.