The epidemiology of tuberculosis among foreign-born persons in the United States, 1986 to 1993

Epidemiology of tuberculosis among different occupational groups in Makkah region, Saudi Arabia

Each year in Saudi Arabia, the Hajj season represents one of the world's most significant annual mass gatherings, attracting high proportion of immigrants from different parts of the world in small crowded areas, posing a risk for Tuberculosis (TB) transmission. There is a high potential for TB contact and infection in the workplace as it is transmitted through the air. Most of the studies in Saudi Arabia assessed the TB infection among health care workers. However, the TB incidence rate among other variant occupational groups was not yet determined. This study was conducted to assess the incidence rate of tuberculosis, and determine the risk factors of TB infection among different occupational groups in the Makkah region, Saudi Arabia 2016. A cross-sectional study was carried out based on the secondary data of the patients registered in the Saudi national tuberculosis control and prevention program in 2016. Data were then organized and analyzed for age, gender, nationality, educational level, average monthly wage, average weekly working hours, and occupation of the patients. Occupations were reclassified according to the Saudi Standard Classification of Occupation (SSCO). A total of 1270 cases were included in this study, 300 (23.6%) of them were workers. The incidence rate of TB among workers in the Makkah region was 9 per 100,000 workers compared to 31 per 100,000 persons among the general population in 2016. The TB incidence rate was the highest among occupation of supporting basic engineering with 13 per 100,000 workers in 2016. The highest incidence rate of TB among occupations of supporting basic engineering could be attributed to close contact with the general population in closed spaces for long periods of time, and low socioeconomic status.

Spinal tuberculosis: a comprehensive review for the modern spine surgeon

Nearly one-third of the human population is infected with tuberculosis. Of those with active disease, approximately 10% are impacted by skeletal tuberculosis. Though, traditionally a disease of the developing world and susceptible populations, with the rise of immigration, patients may present in developed countries. The microbe responsible is the mycobacterium tuberculosis complex bacillus. The infection begins in the anterior vertebral bodies. The natural history and presentation are notable for cold abscesses causing mass effect, early or late neurological deficit, and kyphotic deformity of the spine caused by anterior vertebral body destruction. The disease can be diagnosed with laboratory studies and characteristic imaging findings, but tissue diagnosis with cultures, histology, and polymerase chain reaction is the gold standard. The cornerstone of medical management is multidrug chemotherapy to minimize relapse and drug resistance, and can be curative for spinal tuberculosis with minimal residual kyphosis. Surgical management is reserved for patients presenting with neurological deficits or severe kyphosis. The mainstays of surgical management are debridement, correction of spinal deformity and stable fusion. With appropriate and timely management, clinical outcomes of the treatment of spinal tuberculosis are overall excellent.

A GIS-Based Artificial Neural Network Model for Spatial Distribution of Tuberculosis across the Continental United States

Despite the usefulness of artificial neural networks (ANNs) in the study of various complex problems, ANNs have not been applied for modeling the geographic distribution of tuberculosis (TB) in the US. Likewise, ecological level researches on TB incidence rate at the national level are inadequate for epidemiologic inferences. We collected 278 exploratory variables including environmental and a broad range of socio-economic features for modeling the disease across the continental US. The spatial pattern of the disease distribution was statistically evaluated using the global Moran’s I, Getis–Ord General G, and local Gi* statistics. Next, we investigated the applicability of multilayer perceptron (MLP) ANN for predicting the disease incidence. To avoid overfitting, L1 regularization was used before developing the models. Predictive performance of the MLP was compared with linear regression for test dataset using root mean square error, mean absolute error, and correlations between model output and ground truth. Results of clustering analysis showed that there is a significant spatial clustering of smoothed TB incidence rate (p < 0.05) and the hotspots were mainly located in the southern and southeastern parts of the country. Among the developed models, single hidden layer MLP had the best test accuracy. Sensitivity analysis of the MLP model showed that immigrant population (proportion), underserved segments of the population, and minimum temperature were among the factors with the strongest contributions. The findings of this study can provide useful insight to health authorities on prioritizing resource allocation to risk-prone areas.

Epidemiology and Host Factors

In 2014, WHO reported approximately 9.6 million new cases of tuberculosis (TB) in the world, more than half of which are contributed by developing countries in Asia and Africa. Lack of modern diagnostic tools, underreporting of the new cases and underutilization of directly observed therapy (DOT) remain a concern in developing countries. Transient resurgence of TB during the HIV epidemic has subsided and the annual decline has resumed in developed countries including the USA. In 2014 though, the rate of decline has slowed down resulting in leveling of TB incidence in the USA. In developed countries like the USA, the incidence of TB remains high in those with certain risk factors for TB. This group includes immunocompromised patients, particularly those with positive HIV infection. Others at high risk include those with diabetes, cancer, those taking immunosuppressive drugs, and those with other medical conditions that reduce host immunity. If we look at age and ethnicity, elderly patients are at higher risk of developing TB. African-American, foreign-born, and homeless populations are also at higher risk of developing tuberculosis. Virulence of the mycobacteria, and immunological and genetically mediated factors are also mentioned, but these topics are not the primary goal of this article. This review, thus discusses the epidemiology, host factors, and those at high risk for developing active TB. A brief review of the current trends in drug resistance of mycobacteria is also presented.

Relating annual migration from high tuberculosis burden country of origin to changes in foreign-born tuberculosis notification rates in low-medium incidence European countries

The level of immigration from high tuberculosis (TB) burden countries (HBCs) which impacts on the foreign-born TB notification rate is largely unknown. In this work, we performed a cross-sectional analysis of epidemiological data from 2000 to 2013 from nine European countries: Austria, Denmark, Finland, Hungary, Netherlands, Norway, Spain, Sweden, and the United Kingdom. Crude notification rates were calculated for foreign- and native-born populations and a multiple-linear regression model predicting notification rates with HBC population data was generated. From 2000 to 2013, the population percentage with a foreign birthplace increased on average each year in all nine countries, ranging from +0.11%/year in the Netherlands to +0.66%/year in Spain. An annual increase in HBC migrants above +0.43% per year (95% Confidence Interval: 0.24%-0.63%) corresponded with higher TB notification rates in the foreign-born population of the countries analyzed. This indicates that migration from HBCs can exert a measurable effect on the foreign-born TB notification rate. However, an increase in the foreign-born TB notification rate coincided with an average annual rise in national TB notification rates only in countries, Norway (+3.85%/year) and Sweden (+2.64%/year), which have a high proportion (>80%) of TB cases that are foreign-born.

A Novel Tool Improves Existing Estimates of Recent Tuberculosis Transmission in Settings of Sparse Data Collection

In any setting, a proportion of incident active tuberculosis (TB) reflects recent transmission (“recent transmission proportion”), whereas the remainder represents reactivation. Appropriately estimating the recent transmission proportion has important implications for local TB control, but existing approaches have known biases, especially where data are incomplete. We constructed a stochastic individual-based model of a TB epidemic and designed a set of simulations (derivation set) to develop two regression-based tools for estimating the recent transmission proportion from five inputs: underlying TB incidence, sampling coverage, study duration, clustered proportion of observed cases, and proportion of observed clusters in the sample. We tested these tools on a set of unrelated simulations (validation set), and compared their performance against that of the traditional ‘n-1’ approach. In the validation set, the regression tools reduced the absolute estimation bias (difference between estimated and true recent transmission proportion) in the ‘n-1’ technique by a median [interquartile range] of 60% [9%, 82%] and 69% [30%, 87%]. The bias in the ‘n-1’ model was highly sensitive to underlying levels of study coverage and duration, and substantially underestimated the recent transmission proportion in settings of incomplete data coverage. By contrast, the regression models’ performance was more consistent across different epidemiological settings and study characteristics. We provide one of these regression models as a user-friendly, web-based tool. Novel tools can improve our ability to estimate the recent TB transmission proportion from data that are observable (or estimable) by public health practitioners with limited available molecular data.

Transnational Record Linkage for Tuberculosis Surveillance and Program Evaluation

OBJECTIVE

Pre-immigration tuberculosis (TB) screening, followed by post-arrival rescreening during the first year, is critical to reducing TB among foreign-born people in the United States. However, existing U.S. public health surveillance is inadequate to monitor TB among immigrants during subsequent years. We developed and tested a novel method for ascertaining post-U.S.-arrival TB outcomes among high-TB-risk immigrant cohorts to improve surveillance.

METHODS

We used a probabilistic record linkage program to link pre-immigration screening records from U.S.-bound immigrants from the Philippines (n=422,593) and Vietnam (n=214,401) with the California TB registry during 2000-2010. We estimated sensitivity using Monte Carlo simulations to account for uncertainty in key inputs. Specificity was evaluated by using a time-stratified approach, which defined false-positives as TB records linked to pre-immigration screening records dated after the person had arrived in the United States.

RESULTS

TB was reported in 4,382 and 2,830 people born in the Philippines and Vietnam, respectively, in California during the study period. Of these TB cases, records for 973 and 452 cases of people born in the Philippines and Vietnam, respectively, were linked to pre-immigration screening records. Sensitivity and specificity of linkage were 89% (90% credible interval [CrI] 83, 97) and 100%, respectively, for the Philippines, and 90% (90% CrI 83, 98) and 99.9%, respectively, for Vietnam.

CONCLUSION

Electronic linkage of pre-immigration screening records to a domestic TB registry was feasible, sensitive, and highly specific in two high-priority immigrant cohorts. Transnational record linkage can be used for program evaluation and routine monitoring of post-U.S.-arrival TB risk among immigrants, but requires interagency data sharing and collaboration.

Strengthening tuberculosis control overseas: who benefits?

BACKGROUND

Although tuberculosis is a major cause of morbidity and mortality worldwide, available funding falls far short of that required for effective control. Economic and spillover consequences of investments in the treatment of tuberculosis are unclear, particularly when steep gradients in the disease and response are linked by population movements, such as that between Papua New Guinea (PNG) and the Australian cross-border region.

OBJECTIVE

To undertake an economic evaluation of Australian support for the expansion of basic Directly Observed Treatment, Short Course in the PNG border area of the South Fly from the current level of 14% coverage.

METHODS

Both cost-utility analysis and cost-benefit analysis were applied to models that allow for population movement across regions with different characteristics of tuberculosis burden, transmission, and access to treatment. Cost-benefit data were drawn primarily from estimates published by the World Health Organization, and disease transmission data were drawn from a previously published model.

RESULTS

Investing $16 million to increase basic Directly Observed Treatment, Short Course coverage in the South Fly generates a net present value of roughly $74 million for Australia (discounted 2005 dollars). The cost per disability-adjusted life-year averted and quality-adjusted life-year saved for PNG is $7 and $4.6, respectively.

CONCLUSIONS

Where regions with major disparities in tuberculosis burden and health system resourcing are connected through population movements, investments in tuberculosis control are of mutual benefit, resulting in net health and economic gains on both sides of the border. These findings are likely to inform the case for appropriate investment in tuberculosis control globally.

Screening for imported diseases in an immigrant population: experience from a teaching hospital in Barcelona, Spain

The objective of this study was to describe the screening for imported diseases among an immigrant population. This retrospective observational study was of all adult immigrants attended at the Tropical Medicine Unit of the Vall d'Hebron Teaching Hospital from September of 2007 to March of 2010. The screening strategy was adjusted by symptoms, country of origin, and length of residence in Europe. Overall, 927 patients were included. The median age was 34.5 years, and 42.1% of patients were male. A diagnosis was made in 419 (45.2%) patients. The most frequent diagnoses were Chagas disease, anemia, latent tuberculosis infection, intestinal parasitosis, hepatitis B virus (HBV) infection, and human immunodeficiency virus (HIV) infection. After screening, more diseases were identified in immigrants from sub-Saharan Africa (new diagnoses in 56.6% of patients) than patients from other geographic areas. The geographic origin and length of residence in a developed country determine the prevalence of diseases; hence, screening protocols must be based on this information.

Effectiveness and cost effectiveness of screening immigrants schemes for tuberculosis (TB) on arrival from high TB endemic countries to low TB prevalent countries

BACKGROUND

Immigrants to developed countries are a major source of TB. Therefore amongst strategies adopted for TB control in developed countries include; 1) Screening immigrants at ports of entry referred to as "Port of Arrival Screening" (PoA) and 2) Passive screening (PS) for TB which means screening immigrants through general practices, hospitals, chest-clinics and emergency departments. Evidence of the effectiveness and cost effectiveness of these strategies is not consistent.

OBJECTIVE

Evaluate efficiency of active PoA TB screening for immigrants from TB endemic-regions compared with Passive Screening of immigrant-populations from TB endemic-regions.

METHODS

Major electronic-databases and reference lists of relevant studies were searched. Experts of immigrants' TB screening were contacted for additional studies published or unpublished. Systematic search of major databases identified only retrospective cohort-studies. Their qualities were assessed using Scottish Intercollegiate Guidelines Network (SIGN) methodological checklist for comparative cohort-studies.

RESULTS

Systematic electronic searches identified 1443 citations. Of these 74 studies were retrieved for evaluation against the review's inclusion/exclusion criteria (see study inclusion/exclusion criteria). Four studies met the inclusion criteria (figure 2) which were low in the evidence hierarchy of primary effectiveness studies and had heterogeneities between them. Thus descriptive data-synthesis was performed. Proportionately PoA screening had the lowest percentage of receipt of tuberculin skin test (TST) and the highest percentage of non-attendance for TST reading (table 2). Active PoA screening reduced infectiousness by 34% compared to 30% by passive screening and new entrants screened at PoA were 80% less likely to be hospitalised Odds ratio (OR) = 0.2 (95% confidence interval (CI) 0.1 - 0.2). [Table: see text].

ECONOMIC ANALYSIS

One cost effectiveness analysis was found that compared the costs of; active PoA screening, general practice screening and homeless screening groups. The cost of detecting a case of TB were; £1.26, £13.17 and £96.36 for PS, homeless screening and active PoA screening respectively. The cost of preventing a case of TB were; £6.32, £23.00 and £10.00 for PS, homeless screening and PoA screening respectively, showing there is little difference between the different strategies.

CONCLUSION

Active PoA screening is worth doing with significant benefits including early identification of risk groups with possible timely treatment/chemoprophylaxis intervention, prevention of transmission by significantly reducing infectiousness with subsequent avoidance of hospitalisation in active PoA screening group.

A 33-year-old Haitian immigrant with 7 months of abdominal pain and progressive distension

We report a case of a 33-year-old previously healthy Haitian immigrant with a 7-month history of abdominal pain, fever and ascites. He had a history of positive tuberculin skin test but never underwent treatment for latent tuberculosis (TB) infection. Initial examination showed abdominal distension. Abdominal CT scan showed mild ascites, abnormal soft tissue in the greater omentum and small bowel mesentery, retroperitoneal adenopathy, peritoneal thickening and dilated loops of small bowel. Paracentesis and thoracentesis were initially non-diagnostic. HIV testing was negative. The differential diagnosis included lymphoma and TB peritonitis. The omental mass was biopsied under ultrasound guidance, and histopathology revealed non-necrotising granulomas. Sputum cultures and omental biopsy cultures subsequently grew Mycobacterium tuberculosis, and a diagnosis was made of pulmonary TB with TB peritonitis. The patient responded well to the initiation of anti-TB treatment.

Persistent latent tuberculosis reactivation risk in United States immigrants

RATIONALE

Current guidelines limit latent tuberculosis infection (LTBI) evaluation to persons in the United States less than or equal to 5 years based on the assumption that high TB rates among recent entrants are attributable to high LTBI reactivation risk, which declines over time. We hypothesized that high postarrival TB rates may instead be caused by imported active TB.

OBJECTIVES

Estimate reactivation and imported TB in an immigrant cohort.

METHODS

We linked preimmigration records from a cohort of California-bound Filipino immigrants during 2001-2010 with subsequent TB reports. TB was likely LTBI reactivation if the immigrant had no evidence of active TB at preimmigration examination, likely imported if preimmigration radiograph was abnormal and TB was reported less than or equal to 6 months after arrival, and likely reactivation of inactive TB if radiograph was abnormal but TB was reported more than 6 months after arrival.

MEASUREMENTS AND MAIN RESULTS

Among 123,114 immigrants, 793 TB cases were reported. Within 1 year of preimmigration examination, 85% of TB was imported; 6 and 9% were reactivation of LTBI and inactive TB, respectively. Conversely, during Years 2-9 after U.S. entry, 76 and 24% were reactivation of LTBI and inactive TB, respectively. The rate of LTBI reactivation (32 per 100,000) did not decline during Years 1-9.

CONCLUSIONS

High postarrival TB rates were caused by detection of imported TB through active postarrival surveillance. Among immigrants without active TB at baseline, reported TB did not decline over 9 years, indicating sustained high risk of LTBI reactivation. Revised guidelines should support LTBI screening and treatment more than 5 years after U.S. arrival.

The utility of routine tuberculosis screening in county hospital patients with uveitis

BACKGROUND/AIM

To evaluate the utility of tuberculosis (TB) screening in diagnosing ocular TB in uveitis patients in a government-funded hospital.

METHODS

The charts of 142 consecutive patients seen during August 2011-July 2012 at the Los Angeles County Hospital uveitis clinic were reviewed for manifestation/laterality of uveitis, purified protein derivative (PPD) test results, interferon γ release assay, chest x-ray, birthplace, treatment history and diagnosis. 'Presumed TB-uveitis' was diagnosed when patients had positive TB screening and favourable response to anti-TB therapy, and definite ocular TB when Mycobacterium tuberculosis' presence was demonstrated. Post-test probabilities were determined.

RESULTS

TB screening was positive in 21.1%. Six patients were diagnosed with TB-related uveitis: one definite, four presumed and one systemic TB with uveitis. With regard to PPD positivity, being foreign-born was the only statistically significant factor with OR of 2.26 (95% CI 1.01 to 5.13; p<0.01) if born in Mexico and 4.90 (95% CI 1.74 to 13.83; p<0.01) if born in other foreign countries. The post-test probabilities of a positive PPD in a uveitis patient showed a 17.2% (overall) or 30.3% (foreign-born patients) chance of ocular TB.

CONCLUSIONS

PPD skin test plays an important role in the diagnosis of TB-associated uveitis in high-risk groups, such as immigrants from TB endemic regions.

Tuberculosis among Africans living in the United States, 2000-2009

The incidence of tuberculosis (TB) has declined steadily in the United States; however, foreign-born persons are disproportionately affected. The aim of our study was to describe characteristics of TB patients diagnosed in the United States who originated from the African continent. Using data from the U.S. National Tuberculosis Surveillance System, we calculated TB case rates and analyzed differences between foreign-born patients from Africa compared with other foreign-born and U.S.-born patients. The 2009 TB case rate among Africans (48.1/100,000) was 3 times as high as among other foreign-born and 27 times as high as among U.S.-born patients. Africans living in the United States have high rates of TB disease; they are more likely to be HIV-positive and to have extrapulmonary TB. Identification and treatment of latent TB infection, HIV testing and treatment, and a high index of suspicion for extrapulmonary TB are needed to better address TB in this population.

Psychiatric morbidity and other factors affecting treatment adherence in pulmonary tuberculosis patients

As the overall prevalence of TB remains high among certain population groups, there is growing awareness of psychiatric comorbidity, especially depression and its role in the outcome of the disease. The paper attempts a holistic approach to the effects of psychiatric comorbidity to the natural history of tuberculosis. In order to investigate factors associated with medication nonadherence among patients suffering from tuberculosis, with emphasis on psychopathology as a major barrier to treatment adherence, we performed a systematic review of the literature on epidemiological data and past medical reviews from an historical perspective, followed by theoretical considerations upon the relationship between psychiatric disorders and tuberculosis. Studies reporting high prevalence rates of psychiatric comorbidity, especially depression, as well as specific psychological reactions and disease perceptions and reviews indicating psychiatric complications as adverse effects of anti-TB medication were included. In sum, data concerning factors affecting medication nonadherence among TB patients suggested that better management of comorbid conditions, especially depression, could improve the adherence rates, serving as a framework for the effective control of tuberculosis, but further studies are necessary to identify the optimal way to address such issues among these patients.

The impact of migrant workers on the tuberculosis transmission: general models and a case study for China

A tuberculosis (TB) transmission model involving migrant workers is proposed and investigated. The basic reproduction number R0 is calculated, and is shown to be a threshold parameter for the disease to persist or become extinct in the population. The existence and global attractivity of an endemic equilibrium, if R0 > 1, is also established under some technical conditions. A case study, based on the TB epidemiological and other statistical data in China, indicates that the disease spread can be controlled if effective measures are taken to reduce the reactivation rate of exposed/latent migrant workers. Impact of the migration rate and direction, as well as the duration of home visit stay, on the control of disease spread is also examined numerically.

[Comparative epidemiological study of the tuberculosis - migrant and native subjects in Guadeloupe from 2006 to 2011]

INTRODUCTION

Most of the migrants residing in Guadeloupe are from neighboring Caribbean islands, some of which are characterized by a high incidence of tuberculosis. The objective of this retrospective and observational study was to define the epidemiological characteristics of tuberculosis affecting migrant and native populations in Guadeloupe.

METHODS

We describe all cases of tuberculosis in Guadeloupe identified in these two populations between 1 July 2006 and 30 June 2011.

RESULTS

The incidence of TB among migrants in Guadeloupe was seven times higher than that in native subjects in 2010 (33.4 vs. 5.5 new cases/100,000 inhabitants). Tuberculosis affecting the migrant population was characterized by young age of the patients (42 vs. 55 years) and a significant proportion of co-infection by the human immunodeficiency virus (HIV) (47 vs. 14%, P<0.001). Among the patient population studied, the HIV infection increased the risk of developing severe tuberculosis (adjusted odds ratio: 2.9; 95%CI: 1.2-6.8). Moreover, HIV infection was also a risk factor for death where the infection was not controlled (CD4 count <200 units per microliter; adj risk ratio: 3.9; 1.2-12.4).

CONCLUSION

This study shows that the migrant population in Guadeloupe is at increased risk of tuberculosis and should be considered as a priority target for tuberculosis control program.

Osteomyelitis affecting mandible in tuberculosis patients

Tuberculosis (TB) is a frequent health problem in developing nations. It has two forms pulmonary and secondary causing other kinds of TB, collectively denoted extra pulmonary tuberculosis. The prevalence of extra pulmonary TB has increased in the last couple of years. Maxillofacial manifestations of tuberculosis form nearly 10% of all extra pulmonary manifestations of the disease. Extra pulmonary TB involving maxillofacial region is our prime concern. Very few cases of TB of the temporomandibular joint (TMJ) and mandible have been reported in literature. The clinical appearance of TB infection of the TMJ has been described as unspecific, resembling arthritis, osteomyelitis, cancer or any kind of chronic joint diseases. This article describes two cases where the bone, namely TMJ and angle of mandible are affected by tuberculosis. In addition to conventional radiographs we used Cone Beam Computed tomography (CBCT) to explore the third dimension of the lesion.

Key words:Tuberculosis, bone, osteomyelitis, CBCT.

Active tuberculosis among homeless persons, Toronto, Ontario, Canada, 1998-2007

While tuberculosis (TB) in Canadian cities is increasingly affecting foreign-born persons, homeless persons remain at high risk. To assess trends in TB, we studied all homeless persons in Toronto who had a diagnosis of active TB during 1998–2007. We compared Canada-born and foreign-born homeless persons and assessed changes over time. We identified 91 homeless persons with active TB; they typically had highly contagious, advanced disease, and 19% died within 12 months of diagnosis. The proportion of homeless persons who were foreign-born increased from 24% in 1998–2002 to 39% in 2003–2007. Among foreign-born homeless persons with TB, 56% of infections were caused by strains not known to circulate among homeless persons in Toronto. Only 2% of infections were resistant to first-line TB medications. The rise in foreign-born homeless persons with TB strains likely acquired overseas suggests that the risk for drug-resistant strains entering the homeless shelter system may be escalating.

Tuberculosis among foreign-born persons, Singapore, 2000-2009

We determined the proportion of foreign-born persons with tuberculosis (TB) in Singapore. This proportion increased from 25.5% in 2004 to 37.6% in 2009. Unskilled workers from countries with high incidences of TB accounted for the highest number of and greatest increase in foreign-born TB case-patients.

Re-examining treatment of latent tuberculosis infection

In April 2000, the American Thoracic Society published guidelines for targeted tuberculin testing and the treatment of latent tuberculosis infection (LTBI) (1). These guidelines are a joint statement of the American Thoracic Society and the Centers for Disease Control and Prevention, and were endorsed by both the Infectious Diseases Society of America and the American Academy of Pediatrics. Similar recommendations were published by the Infectious Diseases Society of America in its guidelines for the treatment of tuberculosis (TB) (2). These updated guidelines were developed in recognition of the importance of treating LTBI as one component of eliminating TB in the United States - a goal reiterated in 1999 by the Advisory Council for the Elimination of Tuberculosis (3) - but also realizing the differing risks and benefits of treatment for patients based on their individual risks of developing active disease or drug toxicity (4). The 2000 edition of theCanadian Tuberculosis Standardsprovided similar recommendations for the treatment of LTBI (formerly known as chemoprophylaxis) and reminded us of the two major Canadian TB elimination initiatives: the National Tuberculosis Elimination Strategy (Medical Services Branch, 1992), with the aim of eliminating TB in First Nations people by 2010, and the National Consensus Conference on Tuberculosis (Health Canada, 1997), with an interim goal of a 5% reduction in the number of TB cases each year in Canada (5). Given the recent publication of the American guidelines and the updatedCanadian Tuberculosis Standards(Fifth Edition), it was considered timely to remind readers of the evidence supporting the use of antituberculous chemotherapy in the treatment of latent infection.

Persistent high incidence of tuberculosis among immigrants in a low-incidence country: impact of immigrants with early or late latency

Spread of tuberculosis (TB) due to the immigration from some developing countries with high TB incidence to developed countries poses an increasing challenge in the global TB control. Here a simple compartmental TB model with constant immigration, early and late latency is developed in order to investigate the impact of new immigrants with latent TB on the overall TB incidence, and to compare the difference contributed by different proportions of latently-infected new immigrants with high or low risk to develop active TB shortly after arrival. The global dynamics of the system is completely classified, numerical simulations are carried out for different scenarios, and potential applications to public health policy are discussed.

A comparative examination of tuberculosis immigration medical screening programs from selected countries with high immigration and low tuberculosis incidence rates

BACKGROUND

Tuberculosis (TB) in migrants is an ongoing challenge in several low TB incidence countries since a large proportion of TB in these countries occurs in migrants from high incidence countries. To meet these challenges, several countries utilize TB screening programs. The programs attempt to identify and treat those with active and/or infectious stages of the disease. In addition, screening is used to identify and manage those with latent or inactive disease after arrival. Between nations, considerable variation exists in the methods used in migration-associated TB screening. The present study aimed to compare the TB immigration medical examination requirements in selected countries of high immigration and low TB incidence rates.

METHODS

Descriptive study of immigration TB screening programs.

RESULTS

16 out of 18 eligible countries responded to the written standardized survey and phone interview. Comparisons in specific areas of TB immigration screening programs included authorities responsible for TB screening, the primary objectives of the TB screening program, the yield of detection of active TB disease, screening details and aspects of follow up for inactive pulmonary TB. No two countries had the same approach to TB screening among migrants. Important differences, common practices, common problems, evidence or lack of evidence for program specifics were noted.

CONCLUSIONS

In spite of common goals, there is great diversity in the processes and practices designed to mitigate the impact of migration-associated TB among nations that screen migrants for the disease. The long-term goal in decreasing migration-related introduction of TB from high to low incidence countries remains diminishing the prevalence of the disease in those high incidence locations. In the meantime, existing or planned migration screening programs for TB can be made more efficient and evidenced based. Cooperation among countries doing research in the areas outlined in this study should facilitate the development of improved screening programs.

Primary tuberculosis of the TMJ: presentation of a case and literature review

Tuberculosis (TB) is a frequent health problem. The prevalence of extrapulmonary TB has increased in the last couple of years. Head and neck tuberculosis forms nearly 10% of all extrapulmonary manifestations of the disease. TB of the temporomandibular joint (TMJ) is rare; only a few cases have been reported. The clinical appearance of TB infection of the TMJ has been described as unspecific, resembling arthritis, osteomyelitis, cancer or any kind of chronic joint diseases. This article describes a 22-year-old woman with pain and left preauricular swelling. Magnetic resonance imaging and computed tomography showed an expansive process with destruction of the left condyle and condylar fossa. A fine needle aspiration examination of the swelling showed non-specific granulomatous inflammation. In the following days, a preauricular fistula developed, of which a swab and biopsy specimens were taken. Histological and microbiological examinations revealed an infection with Mycobacterium tuberculosis. The initial antituberculosis treatment consisted of a combination of four antibiotics and could be reduced to two antibiotics in the course of treatment. The treatment was completed successfully after 9 months.

Saudi guidelines for testing and treatment of latent tuberculosis infection

Pulmonary tuberculosis is a common disease in Saudi Arabia. As most cases of tuberculosis are due to reactivation of latent infection, identification of individuals with latent tuberculosis infection (LTBI) who are at increased risk of progression to active disease, is a key element of tuberculosis control programs. Whereas general screening of individuals for LTBI is not cost-effective, targeted testing of individuals at high risk of disease progression is the right approach. Treatment of those patients with LTBI can diminish the risk of progression to active tuberculosis disease in the majority of treated patients. This statement is the first Saudi guideline for testing and treatment of LTBI and is a result of the cooperative efforts of four local Saudi scientific societies. This Guideline is intended to provide physicians and allied health workers in Saudi Arabia with the standard of care for testing and treatment of LTBI.

A review of tuberculosis-related referrals among children in Ireland

BACKGROUND

Immigration has been shown to have an increasingly important effect on the epidemiology of tuberculosis (TB) in developed countries.

AIM

To review patterns of TB-related referrals to a paediatric infectious diseases clinic.

METHODS

Retrospective chart review of TB-related referrals of children attending the Rainbow Clinic at OLCHC between 2003-2005.

RESULTS

Forty-seven children were assessed: 18 referred from public health clinics, 5 from general practitioners, and 24 from paediatricians. Most common reason for referral was history of TB exposure (60%). Eighteen (38%) were female, 29 (62%) were male. Thirteen (28%) had latent TB, and 17 (36%) had active disease. Of children with TB disease, 25 (83%) were Caucasian Irish, and the remainder was African. Twenty-five children completed TB treatment and were discharged, and 2 (7%) were lost to follow-up.

CONCLUSION

Our study highlights the problem of TB in children, the majority of whom are native to this country.

Demographics of tuberculosis in an emerging EU region in Southern Scandinavia

To describe demographics of tuberculosis (TB) in the Øresund region, southern Scandinavia, a retrospective analysis of epidemiological data from TB registers and population databases, from 1995 to 2002, was performed. A total of 2678 TB cases were reported with an overall incidence of 6.3 per 100,000 person-y of observation. There were major differences in notification rates among immigrants depending on their country of origin and their residence in the Øresund region. In the Danish part, 37% of all cases among immigrants came from the Horn of Africa compared to 28% in the Swedish areas. Older age and residence in Denmark were independent risk factors for TB. Comparisons of TB rates within the group of immigrants from the Horn of Africa showed higher rates in the Danish areas compared to the Swedish areas. The discrepancies in notification rates could be explained by different socioeconomic circumstances in the 2 countries or by a greater immigration from highly endemic countries into Denmark during the study period; however, ongoing transmission in specific population groups at high risk of tuberculosis cannot be excluded. This highlights the need for continued and improved surveillance for TB, especially among newly arrived immigrants from highly endemic countries.

Safety of Etanercept in Patients at High Risk for Mycobacterial Tuberculosis Infections

Objective.

The magnitude of the risk of reactivation of tuberculosis (TB) on use of etanercept, especially in patients with positive purified protein derivative (PPD) test, has not been assessed. We evaluated the risk of developing active TB among PPD-positive patients treated with etanercept.

Methods.

All patients with a positive PPD test, as defined by American Thoracic Society guidelines, who received etanercept at Cook County Hospital from 2001 to 2008 were retrospectively reviewed. The primary endpoint was the development of active TB either while receiving or after completing etanercept therapy.

Results.

Four hundred eighty-seven patients received etanercept, of whom 84 were PPD-positive and constituted the primary cohort. The cohort was composed largely of patients who were at high risk for development of active TB: born in endemic area (80%), ethnic/racial minorities (51 Hispanic, 16 African American, and 8 Asian), and low socioeconomic status (66, 78.57%). Overall etanercept exposure was a mean of 24.6 months (range 3 to 60 mo), with 196 patient-years of etanercept exposure in PPD-positive individuals. Indications for etanercept use included rheumatoid arthritis 58 (69%), ankylosing spondylitis 11 (13%), psoriatic arthritis 13 (15.5%), juvenile inflammatory arthritis 1 (1.2%), and vasculitis 1 (1.2%). Of the 80 subjects, 74 received treatment for latent TB infection (LTBI) prior to initiating etanercept. A comprehensive review of these patients’ medical records failed to reveal any active TB infection.

Conclusion.

This systematic analysis suggests that the risk of reactivation of LTBI during etanercept therapy is low in appropriately treated individuals.

Delayed tuberculosis treatment in urban and suburban Ontario

BACKGROUND

Delay in the treatment of patients with tuberculosis (TB) increases the risk of poor clinical outcomes--including death and transmission of disease--and may be reducible.

OBJECTIVE

To estimate delays in TB treatment in a Canadian, multicultural population and to examine factors associated with longer time to treatment.

METHODS

Adult cases of active TB from January 1998 to December 2001 from the Ontario Reportable Disease Information System were included. Time to treatment was defined as the number of days between symptom onset and treatment.

RESULTS

Data from 1753 TB patients (76% of eligible patients) were analyzed. Median time to treatment was 62 days (interquartile range 31 to 114 days). Time periods longer than the median time to treatment were independently associated with middle-aged patients (OR 1.54, 95% CI 1.21 to 1.98), foreign-born patients who had lived in Canada for more than 10 years (OR 1.47, 95% CI 1.02 to 2.12), patients with nonpulmonary disease (OR 1.57, 95% CI 1.28 to 1.92) and patients managed within certain health districts.

CONCLUSION

A time to TB treatment of two months or more is common in Ontario, and associated with several factors. Future studies are needed to build on these findings to decrease delay and improve individual and public health outcomes.

Tuberculosis among foreign-born persons in Taiwan, 2002-2005

BACKGROUND/PURPOSE

The foreign-born population has been growing in Taiwan. Most foreign-born persons come from countries with a high burden of tuberculosis (TB). Monitoring the trend and characteristics of TB in this population is essential for TB control in Taiwan.

METHODS

Information about foreign-born persons residing in Taiwan and data of all foreign-born TB cases notified during 2002-2005 were obtained from the national authorities and analyzed.

RESULTS

A total of 2,444 foreign-born TB cases were notified during 2002-2005, which accounted for 3.6% of all notified TB cases during that period in Taiwan. The proportion of foreign-born TB cases was constant, without any significant yearly variation. The average annual TB notification rate in the foreign-born population was higher than that in the Taiwan-born population (94.0/100,000 vs. 72.0/100,000). There were significant differences in age, sex and regional distribution between foreign-born and Taiwan-born TB cases (p < 0.001). Foreign-born cases were predominantly female (65.4%) and aged 25-44 years (70.9%), whereas the majority of cases among the Taiwan-born population were male (69.4%) and aged > or = 65 years (49.6%). Most foreign-born TB patients (62.7%) lived in northern Taiwan but only about one-third (36.1%) of Taiwan-born TB cases were notified from that region. Among foreign-born TB cases whose original countries were recorded, the majority came from Mainland China and Vietnam, which accounted for 73.0% of all cases, followed by the Philippines (7.4%), Thailand (7.3%) and Indonesia (6.0%).

CONCLUSION

Foreign-born TB patients have different profiles and a higher case rate compared to Taiwan-born patients. Monitoring the epidemiologic trend of TB among foreign-born persons, especially those who come from high TB-burden countries, is essential in the fight against TB in Taiwan.

Timing of therapy for latent tuberculosis infection among immigrants presenting to a U.S. public health clinic: a retrospective study

Background

In the U.S. more than half of incident tuberculosis (TB) cases occur in immigrants. Current guidelines recommend screening and treatment for latent TB infection (LTBI) within 5 years of arrival to the U.S. This study evaluates the timing of LTBI therapy among immigrants presenting for care to a public health TB clinic.

Methods

Retrospective chart review of patients prescribed LTBI treatment based on medical records from Prince Georges County Health Department.

Results

1882 immigrants received LTBI therapy at Prince Georges County Health Department between 1999 and 2004. 417 of these patients were diagnosed with LTBI through contact investigations and were excluded from the analysis. Among the remaining 1465 individuals, median time from arrival to the U.S. until initiation of LTBI therapy was 5 months (range 0–42.4 years). 16% of all immigrants initiated therapy more than 5 years after arrival to the U.S. A logistic regression model using risks identified on univariate analysis revealed that referral for therapy by non-immigration proceedings was the strongest predictor of initiation of therapy more than 5 years after arrival to the U.S. Other factors associated with > 5 year U.S. residence prior to initiation of LTBI therapy included female gender (adjusted odds ratio (AOR) 1.8, 95% CI 1.2–2.6), age ≥ 35 (AOR = 4.1, 95% 2.5–6.6), and originating from Latin American and the Caribbean (AOR = 1.9, 95% CI 1.3–3.0).

Conclusion

Foreign-born individuals who are not referred for LTBI therapy through immigration proceedings are less likely to receive LTBI therapy within 5 years of arrival to the U.S. These data highlight the need to explore other mechanisms for timely LTBI screening beyond services provided by immigration.

Communicable diseases in the immigrant population attended to in a tropical medicine unit: epidemiological aspects and public health issues

For geographical and historical reasons, Spain is receiving an increasing number of immigrants. The aim of this study was to evaluate some epidemiological aspects and the main public health issues of communicable diseases in Barcelona's immigrant population. From 2001 to 2004, a population of immigrants from tropical, subtropical regions and Eastern Europe was attended to in our centre. Each patient was offered a complete screening for tropical and common diseases. The prevalence and demographical characteristics of eight diseases with a potential risk of transmission in our setting were studied: latent and active tuberculosis, syphilis, human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV), Chagas disease, Giardia intestinalis and Entamoeba histolytica/Entamoeba dispar. In all, 2464 immigrants mainly from sub-Saharan Africa were seen. Among the patients who underwent the screening, 46.5% had a positive tuberculin skin test (>or=10 mm), incidence of active tuberculosis was 324.7/100,000 immigrants in the period of the study, 6.4% had a positive syphilis serology, 7.7% had a positive HBsAg, 3.1% had a positive serology for HCV and 2.8% were HIV positive, 41 patients from Latin America with risk factors for American Trypanosomiasis were screened for Chagas disease by immunofluorescence assay and 34% had a positive result; 5.4% of stools parasitological tests were positive for G. intestinalis; 4.2% for E. histolytica/E. dispar. Communicable diseases in immigrant population could lead to emerging and re-emerging infections in the European Union with important issues for public health. European countries may have to establish guidelines for screening of infectious diseases in immigrants from low-income countries.

Modeling the impact of immigration on the epidemiology of tuberculosis

This paper presents two new theoretical frameworks to investigate the impact of immigration on the transmission dynamics of tuberculosis. For the basic model, we present new analysis on the existence and stability of equilibria. Then, we use numerical simulations of the model to illustrate the behavior of the system. We apply the model to Canadian reported data on tuberculosis and observe a good agreement between the model prediction and the data. For the extended model, which incorporated the recruitment of the latent and infectious in immigrants to the basic model, we find that the usual threshold condition does not apply and a unique equilibrium exists for all parameter values. This indicates that the disease does not disappear and becomes endemic in host areas. This finding is also supported by numerical simulations with the extended model. Our study suggests that immigrants have a considerable influence on the overall transmission dynamics behavior of tuberculosis.

Risk of Progression to Active Tuberculosis Among Foreign-Born Persons With Latent Tuberculosis

BACKGROUND

Increased risk for tuberculosis (TB) disease has been identified in foreign-born persons in the United States, particularly during the first 5 years after their arrival in the United States. This could be explained by undetected TB disease at entry, increased prevalence of latent TB infection (LTBI), increased progression from LTBI to TB, or a combination of these factors.

METHODS

We performed a cluster analysis of TB cases in Boston and a case-control study of risk factors for TB with an unclustered isolate among Boston residents with LTBI to determine whether such persons have an increased risk for reactivation of disease.

RESULTS

Of 321 case patients with TB seen between 1996 and 2000, 133 isolates were clustered and 188 were not. In multivariate analysis, foreign birth was associated with an unclustered isolate (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.2 to 3.8; p < 0.01), while being a close contact of a TB case was negatively associated (OR, 0.22; 95% CI, 0.07 to 0.73; p = 0.02). When 188 TB patients with unclustered isolates were compared to 188 age-matched control subjects with LTBI, there was no association between the occurrence of TB and foreign birth (OR, 0.71; 95% CI, 0.42 to 1.3); among foreign-born persons, there was no association between the occurrence of TB and being in the United States <or= 5 years (OR, 0.90; 95% CI, 0.56 to 1.44).

CONCLUSIONS

We conclude that the increased risk for TB among foreign-born persons in the United States may be attributable to the increased prevalence of LTBI among foreign-born persons or the increased prevalence of active disease at arrival in the United States, but not to an increased rate of reactivation among persons with LTBI.

Épidémiologie de la tuberculose en France en 2005

This article presents results on cases of tuberculosis disease notified in France in 2005 by mandatory notification. In 2005, a total of 5,374 cases were notified in France, representing a rate of 8.9 cases per 100,000. The notification rate per 100,000 was below 10 in all French regions, except the Ile-de-France and French Guyana (with respective rates of 19.7/10(5) and 44.0/10(5)). Notification rates were higher in some population groups such as people born abroad (41.5/10(5)), especially those born in sub-Saharan Africa (160/10(5)), and those recently (<2 years) arrived in France (251/10(5)), in homeless people (214/10(5)), and in persons aged 80 years and over (21.7/10(5)). Pulmonary tuberculosis accounted for 73% of notified cases, 79% of which were contagious (positive direct examination of sputum, positive culture). Results from the notification of tuberculosis disease in 2005 indicate a continuing decrease of incidence in France. However, the high incidence in some population groups requires adapting public health actions to the needs of population groups more exposed to tuberculosis.

The epidemiology of tuberculosis among primary refugee arrivals in Minnesota between 1997 and 2001

BACKGROUND

Minnesota (MN) is home to one of the highest number of refugees in the United States. The primary objective of this study was to evaluate the prevalence of latent and active tuberculosis (TB) infection in primary refugee arrivals to MN. Secondary objectives were to determine the association of TB infection with gender, age, and ethnicity of the refugees.

METHODS

A retrospective study of primary refugee arrivals to MN between January 1, 1997, and December 31, 2001, was conducted. Chi-square tests and logistic regression analyses were used to assess the association of TB infection with gender, age, and ethnicity.

RESULTS

Of the 9,842 refugees who had Mantoux test results, 4,990 (50.7%) had a positive test. A positive test was more common in men [odds ratio (OR) = 1.6; p < 0.0001], in Africans (OR = 1.6, p = <0.0001), and increased with 10-year age intervals (OR = 1.4; p < 0.0001). A total of 116 (0.8%) refugees received treatment for active TB. Active TB was more common in men (OR = 1.7; p = 0.006), African ethnicity (OR = 4.3; p < 0.0001), and increased with 10-year age intervals (OR = 1.1; p = 0.05).

CONCLUSIONS

Screening and treatment for latent and active TB should be actively managed among refugees resettling in the United States, as this is common and can have significant public health implications.

Costs and cost-effectiveness of adolescent compliance with treatment for latent tuberculosis infection: results from a randomized trial

PURPOSE

Assess the costs and cost-effectiveness of an incentive-based tuberculosis (TB) program designed to promote adolescents' compliance with treatment for latent TB infection (LTBI).

METHODS

Randomized controlled trial. Adolescents between the ages of 11 and 19 years who were referred to one of two participating clinics after being screened for TB and receiving a positive diagnosis indicating LTBI (n = 794) were assigned to one of four groups: usual care, peer counseling, contingency contracting, and combined peer counseling/contingency contracting. Primary outcome variables were completion of isoniazid preventive therapy (IPT), total treatment costs, and lifetime TB-related costs per quality-adjusted life year (QALY) in each of the four study groups (three treatment, one control). Cost effectiveness was evaluated using a five-stage Markov model and a Monte Carlo simulation with 10,000 trials.

RESULTS

Average costs were 199 dollars for usual care (UC), 277 dollars for peer counseling (PC), 326 dollars for contingency contracting (CC), and 341 dollars for PC + CC combined. The differences among these groups were all significant at the p = .001 level. Only the PC + CC group improved the rate of IPT completion (83.8%) relative to usual care (75.9%) (p = .051), with an overall incremental CE ratio of 209 dollars per QALY relative to usual care.

CONCLUSION

Incentives combined with peer counseling are a cost-effective strategy for helping adolescents to complete care when combined with peer counseling.

Differenzialdiagnose „steriler“ phlegmonöser Entzündungen der Hand

INTRODUCTION

Bacterial infections represent a large proportion of emergencies in hand surgery. In some cases, pyoderma gangrenosum and mycobacterial infection may present with the same symptoms of swelling, pain, and purulent secretion. In these cases, operative treatment would be harmful. Therefore two cases-pyoderma gangrenosum and tuberculosis-are presented here in relation to common bacterial hand infection.

METHODS

Using two case reports of diseases that only rarely affect the hands, their relevance to differential diagnosis is shown with reference to the literature.

RESULTS

In both cases, we found clinical symptoms of bacterial hand infection with negative bacterial smear tests. After several debridements, pyoderma gangrenosum of the dorsum of the hand was diagnosed in one patient after pyodermiform lesions at the thigh and the nasal septum were detected and pre-existing colitis ulcerosa was taken into consideration. Corticoid therapy induced complete remission. The second patient with similar clinical symptoms had been operated on at another hospital several times before being transferred to our institution. The presumptive diagnosis of pyoderma gangrenosum was made, and under treatment with prednisone the symptoms quickly improved. After 2 weeks, the wound conditions and the patient's condition rapidly worsened. Following amputation at the upper arm level, the patient died of septic multiple organ failure. Autopsy studies revealed tuberculous sepsis originating from the hand.

DISCUSSION

Patient history should be evaluated carefully because of its value to correct diagnosis. In case of negative smear tests, especially from immunocompromised, elderly patients and in patients with a history of pulmonary tuberculosis, Ziehl-Neelsen staining should be obtained. In case of multilocular affection or pre-existing chronic inflammatory bowel disease, the presumptive diagnosis of pyoderma gangrenosum can be confirmed by biopsies from the lesions margin. In both cases, unnecessary traumatizing operations could thus be avoided and treatment optimized.

Tuberculosis among foreign-born persons in the United States: achieving tuberculosis elimination

RATIONALE

In the United States, the number of annual reported cases of tuberculosis (TB) among U.S.-born persons declined by 62% from 1993 to 2004, but increased by 5% among foreign-born persons. Over half of all reported cases of TB in the United States occur among foreign-born persons, most of these due to activation of latent TB infection (LTBI). Current guidelines recommend targeting only foreign-born persons who entered the United States within the previous 5 yr for LTBI testing.

OBJECTIVE

We sought to assess the epidemiologic basis for this guideline.

METHODS

We calculated TB case rates among foreign-born persons, stratified by duration of United States residence and world region of origin. We determined the number of cases using 2004 U.S. TB surveillance data, and calculated case rates using population data from the 2004 American Community Survey.

MEASUREMENTS AND MAIN RESULTS

In 2004, a total of 14,517 cases of TB were reported; 3,444 (24%) of these were among foreign-born persons who had entered the United States more than 5 yr previously. The rate of TB disease among foreign-born persons was 21.5/100,000, compared with 2.7/100,000 for U.S.-born persons, and varied by duration of residence and world region of origin.

CONCLUSIONS

Almost one-quarter of all TB cases in the United States occur among foreign-born persons who have resided in the United States for longer than 5 yr; case rates for such persons from selected regions of origin remain substantially elevated. To eliminate TB, we must address the burden of LTBI in this high-risk group.

Illness in returned travelers and immigrants/refugees: the 6-year experience of two Australian infectious diseases units

BACKGROUND

Data comparing returned travelers and immigrants/refugees managed in a hospital setting is lacking.

METHODS

We prospectively collected data on 1,106 patients with an illness likely acquired overseas who presented to two hospital-based Australian infectious diseases units over a 6-year period.

RESULTS

Eighty-three percent of patients were travelers and 17% immigrants/refugees. In travelers, malaria (19%), gastroenteritis/diarrhea (15%), and upper respiratory tract infection (URTI) (7%) were the most common diagnoses. When compared with immigrants/refugees, travelers were significantly more likely to be diagnosed with gastroenteritis/diarrhea [odds ratio (OR) 8], malaria (OR 7), pneumonia (OR 6), URTI (OR 3), skin infection, dengue fever, typhoid/paratyphoid fever, influenza, and rickettsial disease. They were significantly less likely to be diagnosed with leprosy (OR 0.03), chronic hepatitis (OR 0.04), tuberculosis (OR 0.05), schistosomiasis (OR 0.3), and helminthic infection (OR 0.3). In addition, travelers were more likely to present within 1 month of entry into Australia (OR 96), and have fever (OR 8), skin (OR 6), gastrointestinal (OR 5), or neurological symptoms (OR 5) but were less likely to be asymptomatic (OR 0.1) or have anaemia (OR 0.4) or eosinophilia (OR 0.3). Diseases in travelers were more likely to have been acquired via a vector (OR 13) or food and water (OR 4), and less likely to have been acquired via the respiratory (OR 0.2) or skin (OR 0.6) routes. We also found that travel destination and classification of traveler can significantly influence the likelihood of a specific diagnosis in travelers. Six percent of travelers developed a potentially vaccine-preventable disease, with failure to vaccinate occurring in 31% of these cases in the pretravel medical consultation.

CONCLUSIONS

There are important differences in the spectrum of illness, clinical features, and mode of disease transmission between returned travelers and immigrants/refugees presenting to hospital-based Australian infectious diseases units with an illness acquired overseas.