Economic Burden of Bacteremic Melioidosis in Eastern and Northeastern,Thailand

Melioidosis is among the most common causes of septicemia in Thailand, but data on economic burden are limited. We describe the economic impact of bacteremic melioidosis hospitalizations in two Thailand provinces during 2006–2008. Costs are presented in US dollars ($1 = 30.49 Thai Baht). The average annual incidence of bacteremic melioidosis cases per 100,000 persons in Sa Kaeo and Nakhon Phanom was 4.6 and 14.4, respectively. The annual cost of bacteremic melioidosis hospitalizations from the societal perspective, including direct and indirect costs, was $152,159 in Sa Kaeo and $465,303 in Nakhon Phanom. The average cost per fatal case was $14,182 and $14,858 in Sa Kaeo and Nakhon Phanom, respectively. In addition to the high morbidity and mortality, the substantial economic burden of melioidosis further supports the need for investments to identify improved prevention and control strategies for melioidosis.     

Increasing Incidence of Human Melioidosis in Northeast Thailand

Melioidosis is a serious community-acquired infectious disease caused by the Gram-negative environmental bacterium Burkholderia pseudomallei. A prospective cohort study identified 2,243 patients admitted to Sappasithiprasong Hospital in northeast Thailand with culture-confirmed melioidosis between 1997 and 2006. These data were used to calculate an average incidence rate for the province of 12.7 cases of melioidosis per 100,000 people per year. Incidence increased incrementally from 8.0 (95% confidence interval [CI] = 7.2–10.0) in 2000 to 21.3 (95% CI = 19.2–23.6) in 2006 (P < 0.001; χ² test for trend). Male sex, age ≥ 45 years, and either known or undiagnosed diabetes were independent risk factors for melioidosis. The average mortality rate from melioidosis over the study period was 42.6%. The minimum estimated population mortality rate from melioidosis in 2006 was 8.63 per 100,000 people (95% CI = 7.33–10.11), the third most common cause of death from infectious diseases in northeast Thailand after human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and tuberculosis.     

A household survey to assess the burden of influenza in rural Thailand

Little is known about the disease burden of influenza in middle-income tropical countries like Thailand. The recent outbreak of avian influenza (H5N1) and studies on influenza from neighboring countries highlight the need for data on incidence, access to care, and health care cost. In May/ June 2003, we conducted a province-wide household survey using two-stage cluster sampling to determine the burden of influenza-like illness in Sa Kaeo Province. We used the total number of reported influenza that occurred in May 2003 and a prospective study of outpatient influenza in clinic patients to develop an estimate of the annualized incidence of influenza. Of 718 subjects, 16 (2.2%) suffered an episode of influenza-like illness in the preceding month; 14 sought care, of whom 7 went to a hospital facility. Fifty percent reported missing on average 3 days of work or school. The total individual cost per illness episode was 663 baht (15.78 US dollars). The proportion of outpatients with influenza-like illness caused by an influenza virus in May was 16% and the annualized influenza incidence was estimated to be 5,941/100,000 in Sa Kaeo Province. This survey adds to information indicating that in rural Thailand, the burden of influenza is substantial and costs associated with an illness episode are up to 20% of an average monthly income.     

Epidemiology of Burkholderia pseudomallei in Thailand.

The distribution of Burkholderia pseudomallei in soil collected from four regions of Thailand and the frequency of B. pseudomallei infections in patients attending government hospitals throughout Thailand in 1997 were surveyed. A total of 3,585 soil samples collected from 896 sites in four regions of Thailand were cultured for B. pseudomallei using selective enrichment broth and modified Ashdown's agar. The organism was recovered in 4.4%, 6.1%, 20.4%, and 5.9% of the soil samples collected from the northern, central, northeastern, and southern regions, respectively, of Thailand (P < 0.0001). Burkholderia pseudomallei was cultured from 50.1% of the sites in the northeastern region compared with 13.8%, 24.5%, and 18.4% in the northern, central, and southern regions, respectively (P < 0.0001). The infection rate in patients attending government hospitals in the northeastern region (137.9 per 100,000 inpatients) was significantly higher than those in the northern (18 per 100,000 inpatients), central (13.4 per 100,000 inpatients), and southern (14.4 per 100,000 inpatients) regions, respectively (P < 0.0001). It is suggested that melioidosis, which is endemic in Thailand, is associated with the presence of B. pseudomallei in soil.     

Pneumonia surveillance in Thailand: current practice and future needs

We reviewed reported pneumonia cases and deaths in Thailand since 1975 to evaluate the pneumonia surveillance system. In Sa Kaeo Province, we analyzed 3 years in detail (1999--2001) from electronic surveillance data, and compared deaths reported through surveillance to death certificate data in 1999 and 2000. In addition, we interviewed surveillance personnel who collected the data from all 7 hospitals and from a 10% random sample of health centers. Since the mid-1980s, reported illnesses and deaths from pneumonia have been increasing. In Sa Kaeo, an average of 925 pneumonia cases were reported each year, for an estimated average annual incidence of 211 per 100,000. The age-specific incidence peaked at 1,418 per 100,000 in children less than 5 years. In 1999 and 2000, there were 7 and 6 pneumonia deaths, respectively, reported through the surveillance system, compared with 28 and 53, respectively, reported by death certificate. Sixty-two (82%) of the 72 surveillance personnel reported receiving some training, but most of this was informal. Although written criteria to diagnose pneumonia were established in 1996, those who report cases did not know these criteria. A combination of physician, nurse, and public health workers diagnoses were used. According to the written criteria, cases of suspect or rule out pneumonia should be reported, but when asked about specific examples only 79% of persons interviewed said they would report "tuberculosis with pneumonia" and 44% would report "bronchitis, rule out pneumonia." Seventy-four percent of persons interviewed completed the surveillance report within one day of patient admission.     

Temporal patterns and forecast of dengue infection in Northeastern Thailand

This study aimed to determine temporal patterns and develop a forecasting model for dengue incidence in northeastern Thailand. Reported cases were obtained from the Thailand national surveillance system. The temporal patterns were displayed by plotting monthly rates, the seasonal-trend decomposition procedure based on loess (STL) was performed using R 2.2.1 software, and the trend was assessed using Poisson regression. The forecasting model for dengue incidence was performed in R 2.2.1 and Intercooled Stata 9.2 using the seasonal Autoregressive Integrated Moving Average (ARIMA) model. The model was evaluated by comparing predicted versus actual rates of dengue for 1996 to 2005 and used to forecast monthly rates during January to December 2006. The results reveal that epidemics occurred every two years, with approximately three years per epidemic, and that the next epidemic will take place in 2006 to 2008. It was found that if a month increased, the rate ratio for dengue infection decreased by a factor 0.9919 for overall region and 0.9776 to 0.9984 for individual provinces. The amplitude of the peak, which was evident in June or July, was 11.32 to 88.08 times greater than the rest of the year. The seasonal ARIMA (2, 1, 0) (0, 1, 1)12 model was model with the best fit for regionwide data of total dengue incidence whereas the models with the best fit varied by province. The forecasted regional monthly rates during January to December 2006 should range from 0.27 to 17.89 per 100,000 population. The peak for 2006 should be much higher than the peak for 2005. The highest peaks in 2006 should be in Loei, Buri Ram, Surin, Nakhon Phanom, and Ubon Ratchathani Provinces.     

Assessing the sensitivity of surveillance for pneumonia in rural Thailand

We conducted a household survey among Sa Kaeo residents to characterize self-reported health-seeking behavior for pneumonia and the proportion of individuals who seek care at a hospital to determine the coverage of a surveillance system. A 2-stage cluster sample was used to select households. A case of pneumonia was defined as a self-reported history of cough and difficulty breathing for at least 2 days or being given a diagnosis of pneumonia by a healthcare provider in the 12-month period beginning February 1, 2002, and ending January 31, 2003. Interviewers administered a structured questionnaire that asked about clinical illness and utilization of healthcare services. Among 1,600 households, 5,658 persons were surveyed, of whom 62 persons met the case definition. Of the 59 persons with complete data, 53 (90%, 95% CI: 79-96) sought medical care and 47 (80%, 95% CI: 67-89) sought care at a hospital facility in the province. Neither distance nor cost was reported as a barrier to seeking care. Most individuals with self-reported pneumonia sought care at the hospital level. Population-based surveillance can provide reliable estimates of hospitalized, chest radiograph-confirmed pneumonia in Sa Kaeo if adjustments are made to account for the proportion of individuals who access a hospital where radiologic assessment is available.     

Increase in incidence and prevalence of inflammatory bowel disease in northern Denmark: a population-based study, 1978-2002

OBJECTIVES: Although incidence rates of inflammatory bowel disease have been reported worldwide, few long-term population-based studies with current time-trend analyses exist. We therefore examined time trends in the incidence rate of inflammatory bowel disease in a 25-year study period, and estimated the prevalence in 2002. All patients diagnosed between 1978 and 2002 were included as incident cases (n=2,326) and all patients living in North Jutland County on 31 December 2002 were used to estimate prevalent cases (n=2,205). METHODS: Medical records of all patients diagnosed with ulcerative colitis and Crohn's disease in the North Jutland County Hospital Discharge Registry were reviewed to examine if the diagnostic criteria were fulfilled. Age-specific and gender-specific standardized incidence rates were calculated. RESULTS: For ulcerative colitis, incidence rates in women increased from 8.3 (95% confidence interval (CI): 6.7-9.9) in 1978-1982 to 17.0 (95% CI: 14.7-19.3) per 100,000 person-years in 1998-2002. The corresponding figures for men were 7.7 (95% CI: 6.1-9.3) and 16.7 (95% CI: 14.4-18.8) per 100,000 person-years. For Crohn's disease, the incidence rates in women increased from 4.1 (95% CI: 3.0-5.2) in 1978-1982 to 10.7 (95% CI: 8.8-12.5) per 100,000 person-years in 1998-2002. The corresponding figures for men were 3.2 (95% CI: 2.1-4.2) and 8.5 (95% CI: 6.9-10.2) per 100,000 person-years. The prevalence of ulcerative colitis and Crohn's disease was 294 and 151 per 100,000 inhabitants, respectively. CONCLUSIONS: A marked and parallel increase was seen in both ulcerative colitis and Crohn's disease in both genders during the last 25 years, with a corresponding high prevalence of both diseases.     

Secular Trends in Incidence and 30-Day Case Fatality of Acute Pancreatitis in North Jutland County,Denmark: A Register-based Study from 1981-2000

Background: The incidence rate of acute pancreatitis has been reported as having increased during recent decades in Western countries. Reported mortality lies around 10% and has improved during the past 20 years. The incidence rate and 30-day case fatality rate of acute pancreatitis in North Jutland County, Denmark were examined for the period 1981 to 2000. Methods: Data were collected from the Hospital Discharge Registry of North Jutland County for the period 1981-2000. Sex- and age-standardized incidence rates and 30-day case fatality rate of a first attack of acute pancreatitis were calculated. Data on endoscopic procedures were assessed for the period 1992 to 2000 and on certain drugs for 1991 to 1999. Results: The incidence rate of acute pancreatitis in women increased from 17.1 per 100,000 person-years in 1981 (95% confidence interval (CI), 12.6-23.2) to 37.8 per 100,000 person-years in 2000 (95% CI, 31.0-46.1). The corresponding increase in men was from 18 per 100,000 person-years in 1981 (95% CI, 13.3-24.2) to 27.1 per 100,000 person-years in 2000 (95% CI, 21.5-34.3). The incidence rate of acute pancreatitis increased with age in both sexes. The overall 30-day case fatality rate was 7.5% (95% CI, 6.5-8.7) increasing with age, adjusted odds ratio (OR) = 6.4 (95% CI, 3.5-11.6) and decreased with time, adjusted OR = 0.7 (95% CI, 0.4-1.0). Conclusion: The incidence of acute pancreatitis has increased, and in women surpassed that in men in 1999 and 2000. Short-term prognosis has improved.     

Secular trends in incidence and 30-day case fatality of acute pancreatitis in North Jutland County,Denmark: a register-based study from 1981-2000

BACKGROUND: The incidence rate of acute pancreatitis has been reported as having increased during recent decades in Western countries. Reported mortality lies around 10% and has improved during the past 20 years. The incidence rate and 30-day case fatality rate of acute pancreatitis in North Jutland County, Denmark were examined for the period 1981 to 2000. METHODS: Data were collected from the Hospital Discharge Registry of North Jutland County for the period 1981-2000. Sex- and age-standardized incidence rates and 30-day case fatality rate of a first attack of acute pancreatitis were calculated. Data on endoscopic procedures were assessed for the period 1992 to 2000 and on certain drugs for 1991 to 1999. RESULTS: The incidence rate of acute pancreatitis in women increased from 17.1 per 100,000 person-years in 1981 (95% confidence interval (CI), 12.6-23.2) to 37.8 per 100,000 person-years in 2000 (95% CI, 31.0-46.1). The corresponding increase in men was from 18 per 100,000 person-years in 1981 (95% CI, 13.3-24.2) to 27.1 per 100,000 person-years in 2000 (95% CI, 21.5-34.3). The incidence rate of acute pancreatitis increased with age in both sexes. The overall 30-day case fatality rate was 7.5% (95% CI, 6.5-8.7) increasing with age, adjusted odds ratio (OR) = 6.4 (95% CI, 3.5-11.6) and decreased with time, adjusted OR = 0.7 (95% CI, 0.4-1.0). CONCLUSION: The incidence of acute pancreatitis has increased, and in women surpassed that in men in 1999 and 2000. Short-term prognosis has improved.     

Further evidence for the rising incidence of childhood Type 1 diabetes in Kuwait.

AIMS: To provide age-gender standardized incidence rate, temporal trend and seasonal variation of Type 1 diabetes in Kuwaiti children aged < or = 14 years. METHODS: Data were prospectively collected over a period of 6 years (1992-1997) according to the DiaMond Project protocol using the capture-recapture method of ascertainment. RESULTS: Data ascertainment varied between 90% and 96%. The incidence rate of Type 1 diabetes was 20.1 per 100,000 children 0-14 years (95% confidence interval (CI) 18.0-22.1); age-standardized incidence rate 20.9 (95% CI 18.8-23.0). The incidence rate among boys, 21.1 per 100,000 (95% CI 18.1-24.1) was slightly higher than that among girls, 19.0 per 100,000 (95% CI 16.1-21.8). The age-standardized incidence rate was 21.9 (95% CI 18.9-24.8) in boys, and 19.9 (95 CI 17.1-22.8) in girls. Incidence rates increased with age in both sexes (boys chi(2) for linear trend = 13.5, P < 0.001; and for girls chi(2) = 27.8, P < 0.0001). There was a significant trend towards increase in overall incidence during the 6-year period (chi(2) = 6.210, P = 0.013), and in age group 5-9 (chi(2) = 10.8, P = 0.001). Seasonality was demonstrated overall, in boys and girls (P < 0.001). CONCLUSION: The incidence of Type 1 diabetes in Kuwait is high compared with the neighbouring Arab countries, and it appears to be increasing as in many European populations.     

Trichinosis: Epidemiology in Thailand

Trichinosis is one of the most common food-borne parasitic zoonoses in Thailand and many outbreaks are reported each year. This paper reviews the history, species,and epidemiology of the disease and food habits of the people with an emphasis on the north, northeast, central and south regions of Thailand. The earliest record of trichinosis in Thailand was in 1962 in the Mae Sariang District, Mae Hong Son Province. Since then, about 130 outbreaks have been reported involving 7392 patients and 97 deaths (1962-2005). The highest number of cases, 557, was recorded in 1983. The annual epidemiological surveillance reports of the Bureau of Epidemiology,Department of Disease Control, Ministry of Public Health,Thailand, show that trichinosis cases increased from 61 in 1997 to 351 in 1998.In contrast to these figures, the number of reported cases decreased to 16 in 1999 and 128 cases in 2000. There was no record of trichinosis in 2001, but then the figures for 2002, 2003 and 2004 were 289, 126 and 212 respectively. The infected patients were mostly in the 35-44 years age group and the disease occurred more frequently in men than women at a ratio of 1.7-2.0:1. There were 84 reported cases of trichinosis in Chiang Rai, Nan, Chiang Mai, Si Sa ket,Nakhon Phanom, Kalasin, Nakhon Ratchasima, Nakhon Nayok, Nakhon Pathom and Surat Thani, provinces located in different parts of Thailand in 2005. The outbreaks were more common in the northern areas, especially in rural areas where people ate raw or under-cooked pork and/or wild animals. This indicates the need for health education programs to prevent and control trichinosis as soon as possible in the high-risk areas.     

Trichinosis： Epidemiology in Thailand

INTRODUCTIONTrichinosis is one of the most widespread helminthic zoonoses.Unlike other parasitic infections,it has been a major public health problem and reported in many Asian countries,including China,Japan,Korea and Thailand[1-7].Since1835,controversy …     

Risk factors for melioidosis and bacteremic melioidosis.

A case-control study was conducted in four hospitals in northeastern Thailand to identify risk factors for melioidosis and bacteremic melioidosis. Cases were patients with culture-proven melioidosis, and there were two types of controls (those with infections, i.e., with community-acquired septicemia caused by other bacteria, and those without infection, i.e., randomly selected patients admitted with noninfectious diseases to the same hospitals). Demographic data, clinical presentations, and suspected risk factors were analyzed. Diabetes mellitus, preexisting renal diseases, thalassemia, and occupational exposure, classified by the soil and water risk assessment, were confirmed to be significant risk factors for melioidosis and bacteremic melioidosis. Only diabetes mellitus was a significant factor associated with bacteremic melioidosis, as compared with nonbacteremia. A significant interaction was found between diabetes mellitus and occupational exposure. Thus, diabetic rice farmers would be the most appropriate population group for targeted control measures such as vaccination in the future.     

Epidemiology of sporadic inclusion body myositis and polymyositis in Olmsted County, Minnesota

OBJECTIVE: To determine the incidence and prevalence of sporadic inclusion body myositis (sIBM) and polymyositis (PM) in a population-based study. METHODS: Charts of patients with myositis in Olmsted County, Minnesota, USA, from 1981 to 2000 were reviewed. RESULTS: For sIBM, the age- and sex-adjusted incidence rates per 100,000 were 0.79 (95% confidence interval = 0.24-1.35), and for PM, 0.41 (95% CI 0.08-0.73). The age- and sex-adjusted prevalence rates per 100,000 were 7.06 (95% CI 0.87-13.24) for sIBM and 3.45 (95% CI 0.00-7.35) for PM. CONCLUSION: The incidence and prevalence rates for sIBM are higher than previously reported.     

The prevalence and incidence of biopsy-proven lupus nephritis in the UK: Evidence of an ethnic gradient

OBJECTIVE: Renal involvement is a major complication of systemic lupus erythematosus (SLE) and is a strong determinant of morbidity and mortality. There have been no previous studies of the epidemiology of lupus nephritis. Our aim was to establish the prevalence and incidence of biopsy-proven lupus nephritis in the northwest of England in 2001 and to examine the influence of age, sex, and ethnicity. METHODS: Adults (age 18 years and older) with biopsy-proven lupus nephritis were identified from 5 sources: renal biopsy databases, dialysis/transplant databases, nephrologists' patients, clinic lists, and lupus patient groups. The denominator data for the northwest of England were ascertained from the 2001 census. RESULTS: We identified 208 cases of biopsy-proven lupus nephritis (176 women, 32 men): the overall prevalence was 4.4 per 100,000 population (95% confidence interval [95% CI] 3.8-5.0), 7.1 per 100,000 (95% CI 6.1-8.2) in women, and 1.4 per 100,000 (95% CI 1.0-2.0) in men. The prevalence was significantly higher among women in the ethnic subgroups: 110.3 per 100,000 population (95% CI 55.0-197.3) in Chinese patients, 99.2 per 100,000 (95% CI 55.5-163.6) in Afro-Caribbean, 21.4 per 100,000 (95% CI 12.0-35.2) in Indo-Asian (Asians from the Indian subcontinent), and 5.6 per 100,000 (95% CI 4.7-6.7) in white patients. The overall annual incidence rate was 0.40 per 100,000 population per year (95% CI 0.24-0.63), with a rate of 0.68 (95% CI 0.40-1.10) in women and 0.09 (95% CI 0.01-0.32) in men. Capture-recapture methods did not suggest any additional cases. CONCLUSION: This first estimate of the prevalence and incidence of biopsy-proven lupus nephritis demonstrates dramatic differences in prevalence according to ethnicity, with an increasing gradient from the white to the Indo-Asian, Afro-Caribbean, and Chinese populations.     

Increasing incidence of Barrett's oesophagus in the general population

BACKGROUND: Barrett's oesophagus (BO) predisposes to oesophageal adenocarcinoma. Epidemiological data suggest that the incidence of BO is rising but it is unclear whether this reflects a true rise in incidence of BO or an increase in detection secondary to more upper gastrointestinal endoscopies performed. This study aimed to examine the changes in BO incidence relative to the number of upper gastrointestinal endoscopies performed in the general population. METHODS: We conducted a cohort study using the Integrated Primary Care Information database. This general practice research database contains the complete and longitudinal electronic medical records of more than 500,000 persons. RESULTS: In total, 260 incident cases of BO were identified during the study period. The incidence of BO increased from 14.3/100,000 person years in 1997 (95% confidence interval (CI) 8.6-22.4) to 23.1/100,000 person years (95% CI 17.2-30.6) in 2002 (r2 = 0.87). The number of upper gastrointestinal endoscopies decreased from 7.2/1000 person years (95% CI 6.7-7.7) to 5.7/1000 person years (95% CI 5.4-6.1) over the same time period. This resulted in an overall increase in detected BO per 1000 endoscopies from 19.8 (95% CI 12.0-31.0) in 1997 to 40.5 (95% CI 30.0-53.5) in 2002 (r2 = 0.93). The incidence of adenocarcinoma increased from 1.7/100,000 person years (95% CI 0.3-5.4) in 1997 to 6.0/100,000 person years (95% CI 3.3-10.2) in 2002 (r2 = 0.87). CONCLUSION: The incidence of diagnosed BO is increasing, independent of the number of upper gastrointestinal endoscopies that are being performed. This increase in BO incidence will likely result in a further increase in the incidence of oesophageal adenocarcinomas in the near future.     

The incidence of pneumonia in rural Thailand.

BACKGROUND: Pneumonia continues to be a leading infectious disease killer, yet accurately measuring incidence remains a challenge. In 2002, Thailand began active, population-based surveillance for radiographically confirmed pneumonia in Sa Kaeo Province. METHODS: Full-time surveillance officers conducted active case ascertainment at every hospital, and routine audits and a community cluster survey promoted complete and accurate reporting. A case of pneumonia was defined as acute infection with signs or symptoms of lower respiratory tract infection and evidence of new infiltrates. An independent panel of radiologists reviewed digital images of all radiographs. RESULTS: Between September 2002 and August 2003, 777 patients met the case definition. The measured minimum incidence was 177/100,000 but the estimated incidence was as high as 580/100,000 with full adjustment for incomplete chest radiography and access to health care. Seventy-two (9%) patients died and 28% were known to be HIV positive. Fifteen (2%) patients had pneumonia twice during the year. The average cost of hospitalization for an episode of pneumonia ranged from US$490.80 to $628.60. CONCLUSIONS: Pneumonia is a significant and costly public health problem in Thailand. This surveillance system allows precise assessment and monitoring of radiologically confirmed pneumonia and lays the groundwork for the introduction of new vaccines against pneumonia pathogens.     

Seroprevalence of melioidosis in dairy cattle in Chiang Mai Province,northern Thailand

The seroprevalence of melioidosis in dairy cattle in Chiang Mai Province was investigated using of the indirect hemagglutination antibody (IHA) method. Two hundred and fifty-three samples were tested for serum antibodies to Burkholderia pseudomallei. The samples were from a total population of 8,688 dairy cattle in the province; random sampling, stratified by the location of cattle, was used. The seroprevalence was determined as 2% at 1:40 cut-off value, which was estimated to equate to 0.3% to 3.7% (95% CI). This report of relatively low disease prevalence in the animal population corresponds to other prevalence studies of the agent in the environment and the human population in the region. The prevalence is markedly different to that reported from northeastern Thailand, where the disease is highly endemic.     

Melioidosis epidemiology and risk factors from a prospective whole-population study in northern Australia

OBJECTIVES: The aims of this study were to describe the epidemiology of melioidosis in tropical northern Australia and to assess the importance of defined risk factors. METHODS: The data were taken from a 14-year prospective study of 364 cases of melioidosis in the 'Top End' of the Northern Territory. A whole-population logistic regression model was used to estimate the crude and adjusted relative risk (RR) for the defined risk factors. RESULTS: The mean age of the study population was 46.8 years, 264 (72.5%) were male, 178 (49%) were aboriginal Australians and 59 (16.2%) died from melioidosis. Average annual incidence was 19.6 cases per 100 000 population, with an estimated rate of 260 cases per 100,000 diabetics per year. Using a whole-population logistic regression model, the estimated crude and adjusted RR [95% confidence intervals (CI)] for melioidosis were 6.3 (5.1-7.8) and 4.0 (3.2-5.1) for those aged > or = 45 years, 2.3 (1.8-2.9) and 2.4 (1.9-3.0) for males, 2.9 (2.3-3.5) and 3.0 (2.3-4.0) for aboriginal Australians, 21.2 (17.1-26.3) and 13.1 (9.4-18.1) for diabetics, 2.7 (2.2-3.4) and 2.1 (1.6-2.6) for those with excess alcohol consumption, 6.8 (5.4-8.6) and 4.3 (3.4-5.5) for chronic lung disease and 6.7 (4.7-9.6) and 3.2 (2.2-4.8) for chronic renal disease, respectively. CONCLUSIONS: Diabetes, excess alcohol intake, chronic renal disease and chronic lung disease are each independent risk factors for melioidosis. In tropical northern Australia, male sex, aboriginal ethnicity and age of > or = 45 years are also independent predictors for melioidosis. Impaired polymorph function may be critical in the predisposition to melioidosis.