Association of Diabetes and Tuberculosis Disease among US-Bound Adult Refugees, 2009-2014.

Diabetes is associated with an increased risk for active tuberculosis (TB) disease. We conducted a case-control study and found a significant association between diabetes and TB disease among US-bound refugees. These findings underscore the value of collaborative management of both diseases.

Diabetes Among United States-Bound Adult Refugees, 2009-2014.

We reported diabetes prevalence among all US-bound adult refugees and assessed factors associated with disease. We analyzed overseas medical evaluations of US-bound refugees from 2009 through 2014 by using CDC's Electronic Disease Notification System. We identified refugees with diabetes by searching for diabetes-related keywords and medications in examination forms with text-parsing techniques. Age-adjusted prevalence rates were reported and factors associated with diabetes were assessed by using logistic regression. Of 248,850 refugees aged ≥18 years examined over 5 years, 5767 (2.3 %) had diabetes. Iraqis had the highest crude (5.1 %) and age-adjusted (8.9 %) prevalence of disease. Higher age group and body mass index were associated with diabetes in all regions. Diabetes prevalence varied by refugee nationality. Although the absolute rates were lower than rates in the United States, the prevalence is still concerning given the younger age of the population and their need for health services upon resettlement.

A cost-benefit analysis of a proposed overseas refugee latent tuberculosis infection screening and treatment program.

BACKGROUND: This study explored the effect of screening and treatment of refugees for latent tuberculosis infection (LTBI) before entrance to the United States as a strategy for reducing active tuberculosis (TB). The purpose of this study was to estimate the costs and benefits of LTBI screening and treatment in United States bound refugees prior to arrival. METHODS: Costs were included for foreign and domestic LTBI screening and treatment and the domestic treatment of active TB. A decision tree with multiple Markov nodes was developed to determine the total costs and number of active TB cases that occurred in refugee populations that tested 55, 35, and 20 % tuberculin skin test positive under two models: no overseas LTBI screening and overseas LTBI screening and treatment. For this analysis, refugees that tested 55, 35, and 20 % tuberculin skin test positive were divided into high, moderate, and low LTBI prevalence categories to denote their prevalence of LTBI relative to other refugee populations. RESULTS: For a hypothetical 1-year cohort of 100,000 refugees arriving in the United States from regions with high, moderate, and low LTBI prevalence, implementation of overseas screening would be expected to prevent 440, 220, and 57 active TB cases in the United States during the first 20 years after arrival. The cost savings associated with treatment of these averted cases would offset the cost of LTBI screening and treatment for refugees from countries with high (net cost-saving: $4.9 million) and moderate (net cost-saving: $1.6 million) LTBI prevalence. For low LTBI prevalence populations, LTBI screening and treatment exceed expected future TB treatment cost savings (net cost of $780,000). CONCLUSIONS: Implementing LTBI screening and treatment for United States bound refugees from countries with high or moderate LTBI prevalence would potentially save millions of dollars and contribute to United States TB elimination goals. These estimates are conservative since secondary transmission from tuberculosis cases in the United States was not considered in the model.

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.

Cost-Effectiveness of Screening and Treating Foreign-Born Students for Tuberculosis before Entering the United States.

INTRODUCTION: The Centers for Disease Control and Prevention is considering implementation of overseas medical screening of student-visa applicants to reduce the numbers of active tuberculosis cases entering the United States. OBJECTIVE: To evaluate the costs, cases averted, and cost-effectiveness of screening for, and treating, tuberculosis in United States-bound students from countries with varying tuberculosis prevalence. METHODS: Costs and benefits were evaluated from two perspectives, combined and United States only. The combined perspective totaled overseas and United States costs and benefits from a societal perspective. The United States only perspective was a domestic measure of costs and benefits. A decision tree was developed to determine the cost-effectiveness of tuberculosis screening and treatment from the combined perspective. RESULTS: From the United States only perspective, overseas screening programs of Chinese and Indian students would prevent the importation of 157 tuberculosis cases annually, and result in $2.7 million in savings. From the combined perspective, screening programs for Chinese students would cost more than $2.8 million annually and screening programs for Indian students nearly $440,000 annually. From the combined perspective, the incremental cost for each tuberculosis case averted by screening Chinese and Indian students was $22,187 and $15,063, respectively. Implementing screening programs for German students would prevent no cases in most years, and would result in increased costs both overseas and in the United States. The domestic costs would occur because public health departments would need to follow up on students identified overseas as having an elevated risk of tuberculosis. CONCLUSIONS: Tuberculosis screening and treatment programs for students seeking long term visas to attend United States schools would reduce the number of tuberculosis cases imported. Implementing screening in high-incidence countries could save the United States millions of dollars annually; however there would be increased costs incurred overseas for students and their families.

Effect of a culture-based screening algorithm on tuberculosis incidence in immigrants and refugees bound for the United States: a population-based cross-sectional study.

BACKGROUND: Before 2007, immigrants and refugees bound for the United States were screened for tuberculosis (TB) by a smear-based algorithm that could not diagnose smear-negative/culture-positive TB. In 2007, the Centers for Disease Control and Prevention implemented a culture-based algorithm. OBJECTIVE: To evaluate the effect of the culture-based algorithm on preventing the importation of TB to the United States by immigrants and refugees from foreign countries. DESIGN: Population-based, cross-sectional study. SETTING: Panel physician sites for overseas medical examination. PATIENTS: Immigrants and refugees with TB. MEASUREMENTS: Comparison of the increase of smear-negative/culture-positive TB cases diagnosed overseas among immigrants and refugees by the culture-based algorithm with the decline of reported cases among foreign-born persons within 1 year after arrival in the United States from 2007 to 2012. RESULTS: Of the 3 212 421 arrivals of immigrants and refugees from 2007 to 2012, a total of 1 650 961 (51.4%) were screened by the smear-based algorithm and 1 561 460 (48.6%) were screened by the culture-based algorithm. Among the 4032 TB cases diagnosed by the culture-based algorithm, 2195 (54.4%) were smear-negative/culture-positive. Before implementation (2002 to 2006), the annual number of reported cases among foreign-born persons within 1 year after arrival was relatively constant (range, 1424 to 1626 cases; mean, 1504 cases) but decreased from 1511 to 940 cases during implementation (2007 to 2012). During the same period, the annual number of smear-negative/culture-positive TB cases diagnosed overseas among immigrants and refugees bound for the United States by the culture-based algorithm increased from 4 to 629. LIMITATION: This analysis did not control for the decline in new arrivals of nonimmigrant visitors to the United States and the decrease of incidence of TB in their countries of origin. CONCLUSION: Implementation of the culture-based algorithm may have substantially reduced the incidence of TB among newly arrived, foreign-born persons in the United States. PRIMARY FUNDING SOURCE: None.

Evaluation of QuantiFERON-TB gold in-tube and tuberculin skin tests among immigrant children being screened for latent tuberculosis infection.

BACKGROUND: Centers for Disease Control and Prevention requirements for pre-immigration tuberculosis (TB) screening of children 2- to 14-years old permit a tuberculin skin test (TST) or an interferon-gamma release assay (IGRA). Few data are available on the performance of IGRAs versus TSTs in foreign-born children. METHODS: We compared the performance of TST and QuantiFERON-TB (QFT) Gold In-Tube in children 2- to 14-years old applying to immigrate to the United States from Mexico, the Philippines and Vietnam, using diagnosis of TB in immigrating family members as a measure of potential exposure. RESULTS: We enrolled 2520 children: 664 (26%) were TST+ and 142 (5.6%) were QFT+. One hundred and eleven (4.4%) were TST+/QFT+, 553 (21.9%) were TST+/QFT- and 31 (1.2%) were TST-/QFT+. Agreement between tests was poor (κ = 0.20). Although positive results of both tests were significantly associated with older age (relative risks [RR] TST+, 1.64; 95% confidence interval [CI]: 1.36-1.97; RR QFT+, 3.05; 95% CI: 1.72-5.38) and with the presence of TB in at least 1 immigrating family member (RR TST+, 1.40; 95% CI: 1.12-1.75; RR QFT+ 2.24; 95% CI: 1.18-4.28), QFT+ results were more strongly associated with both predictive variables. CONCLUSIONS: The findings support the preferential use of QFT over TST for pre-immigration screening of foreign-born children 2 years of age and older and lend support to the preferential use of IGRAs in testing foreign-born children for latent TB infection.

Tuberculin Skin Tests versus Interferon-Gamma Release Assays in Tuberculosis Screening among Immigrant Visa Applicants.

Objective. Use of tuberculin skin tests (TSTs) and interferon gamma release assays (IGRAs) as part of tuberculosis (TB) screening among immigrants from high TB-burden countries has not been fully evaluated. Methods. Prevalence of Mycobacterium tuberculosis infection (MTBI) based on TST, or the QuantiFERON-TB Gold test (QFT-G), was determined among immigrant applicants in Vietnam bound for the United States (US); factors associated with test results and discordance were assessed; predictive values of TST and QFT-G for identifying chest radiographs (CXRs) consistent with TB were calculated. Results. Of 1,246 immigrant visa applicants studied, 57.9% were TST positive, 28.3% were QFT-G positive, and test agreement was 59.4%. Increasing age was associated with positive TST results, positive QFT-G results, TST-positive but QFT-G-negative discordance, and abnormal CXRs consistent with TB. Positive predictive values of TST and QFT-G for an abnormal CXR were 25.9% and 25.6%, respectively. Conclusion. The estimated prevalence of MTBI among US-bound visa applicants in Vietnam based on TST was twice that based on QFT-G, and 14 times higher than a TST-based estimate of MTBI prevalence reported for the general US population in 2000. QFT-G was not better than TST at predicting abnormal CXRs consistent with TB.

Tuberculosis screening by tuberculosis skin test or QuantiFERON-TB Gold In-Tube Assay among an immigrant population with a high prevalence of tuberculosis and BCG vaccination.

RATIONALE: Each year 1 million persons acquire permanent U.S. residency visas after tuberculosis (TB) screening. Most applicants undergo a 2-stage screening with tuberculin skin test (TST) followed by CXR only if TST-positive at > 5 mm. Due to cross reaction with bacillus Calmette-Guérin (BCG), TST may yield false positive results in BCG-vaccinated persons. Interferon gamma release assays exclude antigens found in BCG. In Vietnam, like most high TB-prevalence countries, there is universal BCG vaccination at birth. OBJECTIVES: 1. Compare the sensitivity of QuantiFERON-TB Gold In-Tube Assay (QFT) and TST for culture-positive pulmonary TB. 2. Compare the age-specific and overall prevalence of positive TST and QFT among applicants with normal and abnormal CXR. METHODS: We obtained TST and QFT results on 996 applicants with abnormal CXR, of whom 132 had TB, and 479 with normal CXR. RESULTS: The sensitivity for tuberculosis was 86.4% for QFT; 89.4%, 81.1%, and 52.3% for TST at 5, 10, and 15 mm. The estimated prevalence of positive results at age 15-19 years was 22% and 42% for QFT and TST at 10 mm, respectively. The prevalence increased thereafter by 0.7% year of age for TST and 2.1% for QFT, the latter being more consistent with the increase in TB among applicants. CONCLUSIONS: During 2-stage screening, QFT is as sensitive as TST in detecting TB with fewer requiring CXR and being diagnosed with LTBI. These data support the use of QFT over TST in this population.

Disease surveillance among newly arriving refugees and immigrants--Electronic Disease Notification System, United States, 2009.

PROBLEM/CONDITION: Approximately 450,000 legal permanent immigrants and 75,000 refugees enter the United States annually after receiving required medical examinations by overseas panel physicians (physicians who follow the CDC medical screening guidelines provided to the U.S. Department of State). CDC has the regulatory responsibility for preventing the introduction, transmission, and spread of communicable diseases into the United States as well as for developing the guidelines, known as technical instructions, for the overseas medical examinations. Other conditions that are not infectious might preclude an immigrant or refugee from entering the United States and also are reported as part of the medical examination. After arrival in the United States, all refugees are recommended to obtain a medical assessment by a health-care provider or a health department within 30 days. In addition, immigrants with certain medical conditions such as noninfectious tuberculosis at the time of the original medical examination are recommended to be evaluated after arrival to ensure that appropriate prevention or treatment measures are instituted. Health departments need timely and accurate notifications of newly arriving immigrants, refugees, and persons with other visa types to facilitate these evaluations. Notifications for all newly arriving refugees (with or without medical conditions) and immigrants with medical conditions are provided by CDC's Electronic Disease Notification (EDN) system. This is the first report describing EDN. REPORTING PERIOD: This report summarizes notifications by the EDN system during January-December 2009. DESCRIPTION OF SYSTEM: The EDN system is a centralized electronic reporting system that collects health information on newly arriving refugees and immigrants with Class A and Class B medical conditions. Class A conditions render applicants inadmissible and require a waiver for entry; Class B conditions are admissible but might require treatment or follow-up. Information in the EDN system is used to notify state health departments in all 50 states and the District of Columbia about the arrival of these persons in the United States. RESULTS: In 2009, the EDN system notified U.S. state and local health departments of 104,954 newly arriving refugees and immigrants, of whom 78,899 (75.2%) were refugees (with or without medical conditions), 19,358 (18.4%) were immigrants with medical conditions, and 6,697 (6.4%) were persons with other visa types. Of the 78,899 refugees, 21,319 (27%) had a medical condition. The majority (93.4%) of immigrants with medical conditions had tuberculosis classifications (i.e., either had evidence of latent tuberculosis infection or chest radiograph findings interpreted by the overseas panel physician as consistent with tuberculosis). Of the 41,415 refugees and immigrants with Class A or Class B medical conditions, 405 (1%) had Class A conditions, and 40,994 (99%) had Class B conditions. The majority of refugees and immigrants with suspected Class B tuberculosis were born in the Philippines (41.3%), Mexico (12.1%), Burma (8.7%), Vietnam (7.8%), and the Dominican Republic (5.8%). The majority of refugee notifications were for persons born in Iraq (23.9%), Burma (18.9%), and Bhutan (15.1%). Approximately one third of the tuberculosis notifications were sent to health departments in California (20.5%), Texas (9.8%), and New York (6.3%), and the national reporting rate for tuberculosis follow-up was 75.4% within 30 days of arrival. INTERPRETATION: The findings in this report suggest that 1) overseas medical screening results in a low frequency (0.4%) of inadmissible medical conditions in the United States, 2) the EDN system provides more direct notifications to health departments than the previous paper-based system about newly arriving immigrants and refugees who need medical follow-up, and 3) approximately 75% of follow-up occurs among persons with suspected tuberculosis who are reported to EDN by states receiving newly arriving refugees and immigrants. PUBLIC HEALTH ACTIONS: The data in this report can be used to help state and local health departments provide prompt and effective follow-up, evaluation, and treatment to newly arriving immigrants and refugees. Timely follow-up might prevent additional spread of tuberculosis or other communicable diseases of public health significance into their communities. In addition, information from the EDN system allows health departments to use their resources as effectively as possible by providing clinical information that identifies the refugees and immigrants who should be prioritized for evaluation and treatment.

Attribution of foodborne illnesses, hospitalizations, and deaths to food commodities by using outbreak data, United States, 1998-2008.

Each year, >9 million foodborne illnesses are estimated to be caused by major pathogens acquired in the United States. Preventing these illnesses is challenging because resources are limited and linking individual illnesses to a particular food is rarely possible except during an outbreak. We developed a method of attributing illnesses to food commodities that uses data from outbreaks associated with both simple and complex foods. Using data from outbreak-associated illnesses for 1998-2008, we estimated annual US foodborne illnesses, hospitalizations, and deaths attributable to each of 17 food commodities. We attributed 46% of illnesses to produce and found that more deaths were attributed to poultry than to any other commodity. To the extent that these estimates reflect the commodities causing all foodborne illness, they indicate that efforts are particularly needed to prevent contamination of produce and poultry. Methods to incorporate data from other sources are needed to improve attribution estimates for some commodities and agents.

Correction: The Increasing Burden of Imported Chronic Hepatitis B - United States, 1974-2008.

[This corrects the article DOI: 10.1371/journal.pone.0027717.].

Estimating the impact of newly arrived foreign-born persons on tuberculosis in the United States.

BACKGROUND: Among approximately 163.5 million foreign-born persons admitted to the United States annually, only 500,000 immigrants and refugees are required to undergo overseas tuberculosis (TB) screening. It is unclear what extent of the unscreened nonimmigrant visitors contributes to the burden of foreign-born TB in the United States. METHODOLOGY/PRINCIPAL FINDINGS: We defined foreign-born persons within 1 year after arrival in the United States as "newly arrived", and utilized data from U.S. Department of Homeland Security, U.S. Centers for Disease Control and Prevention, and World Health Organization to estimate the incidence of TB among newly arrived foreign-born persons in the United States. During 2001 through 2008, 11,500 TB incident cases, including 291 multidrug-resistant TB incident cases, were estimated to occur among 20,989,738 person-years for the 1,479,542,654 newly arrived foreign-born persons in the United States. Of the 11,500 estimated TB incident cases, 41.6% (4,783) occurred among immigrants and refugees, 36.6% (4,211) among students/exchange visitors and temporary workers, 13.8% (1,589) among tourists and business travelers, and 7.3% (834) among Canadian and Mexican nonimmigrant visitors without an I-94 form (e.g., arrival-departure record). The top 3 newly arrived foreign-born populations with the largest estimated TB incident cases per 100,000 admissions were immigrants and refugees from high-incidence countries (e.g., 2008 WHO-estimated TB incidence rate of ≥100 cases/100,000 population/year; 235.8 cases/100,000 admissions, 95% confidence interval [CI], 228.3 to 243.3), students/exchange visitors and temporary workers from high-incidence countries (60.9 cases/100,000 admissions, 95% CI, 58.5 to 63.3), and immigrants and refugees from medium-incidence countries (e.g., 2008 WHO-estimated TB incidence rate of 15-99 cases/100,000 population/year; 55.2 cases/100,000 admissions, 95% CI, 51.6 to 58.8). CONCLUSIONS/SIGNIFICANCE: Newly arrived nonimmigrant visitors contribute substantially to the burden of foreign-born TB in the United States. To achieve the goals of TB elimination, direct investment in global TB control and strategies to target nonimmigrant visitors should be considered.

The increasing burden of imported chronic hepatitis B--United States, 1974-2008.

BACKGROUND: Without intervention, up to 25% of individuals chronically infected with hepatitis B virus (HBV) die of late complications, including cirrhosis and liver cancer. The United States, which in 1991 implemented a strategy to eliminate HBV transmission through universal immunization, is a country of low prevalence. Approximately 3,000-5,000 U.S.-acquired cases of chronic hepatitis B have occurred annually since 2001. Many more chronically infected persons migrate to the United States yearly from countries of higher prevalence. Although early identification of chronic HBV infection can reduce the likelihood of transmission and late complications, immigrants are not routinely screened for HBV infection during or after immigration. METHODS: To estimate the number of imported cases of chronic hepatitis B, we multiplied country-specific prevalence estimates by the yearly number of immigrants from each country during 1974-2008. RESULTS: During 1974-2008, 27.9 million immigrants entered the U.S. Sixty-three percent were born in countries of intermediate or high chronic hepatitis B prevalence (range 2%-31%). On average, an estimated 53,800 chronic hepatitis B cases were imported to the U.S. yearly from 2004 through 2008. The Philippines, China, and Vietnam contributed the most imported cases (13.4%, 12.5%, and 11.0%, respectively). Imported cases increased from an estimated low of 105,750 during the period 1974-1977 to a high of 268,800 in 2004-2008. CONCLUSIONS: Imported chronic hepatitis B cases account for approximately 95% of new U.S. cases. Earlier case identification and management of infected immigrants would strengthen the U.S. strategy to eliminate HBV transmission, and could delay disease progression and prevent some deaths among new Americans.

Recipes for foodborne outbreaks: a scheme for categorizing and grouping implicated foods.

BACKGROUND: To better understand the sources of foodborne illness, we propose a scheme for categorizing foods implicated in investigations of outbreaks of foodborne diseases. Because nearly 2000 foods have been reported as causing outbreaks in the United States, foods must be grouped for meaningful analyses. METHODS: We defined a hierarchy of 17 mutually exclusive food commodities. We defined the following three commodity groups from which nearly all food is derived: aquatic animals, land animals, and plants. We defined three commodities in aquatic animals, six in land animals, and eight in plants. We considered each food as a set of ingredients composed of one or more commodities. We defined a simple food as one made of ingredients that are all in one commodity and a complex food as one containing ingredients in more than one commodity. We determined likely ingredients using a panel of epidemiologists and a web-based search process. RESULTS: We assigned 1709 (95%) of the 1794 foods implicated in outbreaks of foodborne diseases reported to Centers for Disease Control and Prevention from 1973 to 2006. Of those, 987 (57%) were simple foods and 722 (43%) were complex foods. DISCUSSION: This categorization may serve as an input for modeling the attribution of human illness to specific food commodities and could be used by policy makers, health officials, regulatory agencies, and consumer groups to evaluate the contribution of various food commodities to illness.

Overseas screening for tuberculosis in U.S.-bound immigrants and refugees.

BACKGROUND: In 2007, a total of 57.8% of the 13,293 new cases of tuberculosis in the United States were diagnosed in foreign-born persons, and the tuberculosis rate among foreign-born persons was 9.8 times as high as that among U.S.-born persons (20.6 vs. 2.1 cases per 100,000 population). Annual arrivals of approximately 400,000 immigrants and 50,000 to 70,000 refugees from overseas are likely to contribute substantially to the tuberculosis burden among foreign-born persons in the United States. METHODS: The Centers for Disease Control and Prevention (CDC) collects information on overseas screening for tuberculosis among U.S.-bound immigrants and refugees, along with follow-up evaluation after their arrival in the United States. We analyzed screening and follow-up data from the CDC to study the epidemiology of tuberculosis in these populations. RESULTS: From 1999 through 2005, a total of 26,075 smear-negative cases of tuberculosis (i.e., cases in which a chest radiograph was suggestive of active tuberculosis but sputum smears were negative for acid-fast bacilli on 3 consecutive days) and 22,716 cases of inactive tuberculosis (i.e., cases in which a chest radiograph was suggestive of tuberculosis that was no longer clinically active) were diagnosed by overseas medical screening of 2,714,223 U.S.-bound immigrants, representing prevalences of 961 cases per 100,000 persons (95% confidence interval [CI], 949 to 973) and 837 cases per 100,000 persons (95% CI, 826 to 848), respectively. Among 378,506 U.S.-bound refugees, smear-negative tuberculosis was diagnosed in 3923 and inactive tuberculosis in 10,743, representing prevalences of 1036 cases per 100,000 persons (95% CI, 1004 to 1068) and 2838 cases per 100,000 persons (95% CI, 2785 to 2891), respectively. Active pulmonary tuberculosis was diagnosed in the United States in 7.0% of immigrants and refugees with an overseas diagnosis of smear-negative tuberculosis and in 1.6% of those with an overseas diagnosis of inactive tuberculosis. CONCLUSIONS: Overseas screening for tuberculosis with follow-up evaluation after arrival in the United States is a high-yield intervention for identifying tuberculosis in U.S.-bound immigrants and refugees and could reduce the number of tuberculosis cases among foreign-born persons in the United States.

Virulence gene- and pandemic group-specific marker profiling of clinical Vibrio parahaemolyticus isolates.

Vibrio parahaemolyticus is a halophilic bacterium capable of causing food- and waterborne gastroenteritis, wound infections, and septicemia in humans. The organism has recently received increasing attention, as the emergence of a new clone, V. parahaemolyticus O3:K6, has resulted in the first documented pandemic spread of V. parahaemolyticus. We used microarray analyses to explore the presence of known virulence factors and genetic markers thought to be specific for V. parahaemolyticus O3:K6 and its clonal derivatives. Analyses of 48 human clinical isolates collected between 1997 and 2005 revealed that the V. parahaemolyticus chromosome 2 type III secretion system is not specifically associated with pandemic strains and can be found in tdh-negative (i.e., Kanagawa-negative) clinical isolates. These results highlight the genetic dynamism of V. parahaemolyticus and aid in refining the genetic definition of the pandemic group members.

Urolithiasis associated with experimental lymphocytic choriomeningitis virus inoculation in Lewis rats.

A high frequency of struvite urolithiasis, hydronephrosis, and other urinary tract lesions developed in a group of Lewis rats inoculated intracranially with lymphocytic choriomeningitis virus (LCMV). Initially, clinically ill rats were referred to necropsy: 30 rats over 3 years. These rats had high frequency of urolithiasis (8/30, 27%), hydronephrosis (12/30, 40%), cystitis (9/30, 30%), transitional cell carcinoma (4/30, 13%), and pyelonephritis (19/30, 63%). Lesions were more common in LCMV-inoculated rats. After this trend was noted, all rats on this protocol were necropsied as part of a cohort study (n = 144). Although the apparent frequency of disease was lower due to increased sampling, there still was a high number of urolithiasis (9/144, 6%) and hydronephrosis (40/144, 28%) cases. All cases of urolithiasis developed in rats inoculated with LCMV (9/44, 20%), as did most cases of hydronephrosis (31/44, 70%). Although sham-injected and uninoculated control rats also had high frequency of hydronephrosis (6/57 [11%] and 3/43 [7%], respectively), LCMV-inoculated rats had a significantly higher frequency of disease than did sham inoculated (P < 0.0001) and uninoculated (P < 0.0001) controls. These results suggest that Lewis rats may be predisposed to developing lesions of the urinary tract, and that intracranial inoculation of rats with LCMV augments this tendency, leading to formation of struvite calculi and associated urinary tract disease.