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.

Persistent eosinophilia and Strongyloides infection in Montagnard refugees after presumptive albendazole therapy.

Chronic helminth infections are common in refugee populations and may persist years after immigration. Asymptomatic Strongyloides stercoralis infection raises particular concern because of its potential for complications in immunosuppressed patients. We examined 172 Montagnard refugees resettled to Wake County, North Carolina from 2002 through 2003. Refugees were pretreated with albendazole for five days and screened for health conditions after arrival. Eosinophilia was present in 41 of 171 refugees at the first blood draw. Only 1 of 172 had a stool helminth (Fasciola) identified by microscopy. On repeat testing, 13 people had persistent eosinophilia. Results of serologic analysis for Strongyloides were available in 24 persons. Eosinophil counts decreased significantly after treatment with ivermectin in nine refugees (P = 0.039). Persistent eosinophilia, likely caused by Strongyloides infection, was common in this cohort of Montagnard refugees. Clinicians should understand the limitations of stool microscopy in diagnosis of strongyloidiasis, the limited effectiveness of albendazole in treating strongyloidiasis, and the importance of following-up refugees with persistent eosinophilia.

Evaluation of the impact of overseas pre-departure treatment for infection with intestinal parasites among Montagnard refugees migrating from Cambodia to North Carolina.

We evaluated the effectiveness of an overseas pre-departure regimen of five days of albendazole for presumptive treatment of intestinal parasites by examining stool specimens in treated and untreated Montagnard refugees after arrival in the United States. Among 815 refugees evaluated, fully treated refugees had a significantly lower prevalence of helminths (11 [1.4%] of 777), specifically hookworm and Ascaris lumbricoides, than untreated pregnant women (3 [20%] of 15) (P < 0.001). Multivariate analysis showed that treatment was associated with significantly lower rates of infection with helminths but not protozoa. Post-arrival gastrointestinal symptoms were not associated with findings on stool examination. Our evaluation suggests that although additional studies are needed to determine optimal treatment regimens for intestinal parasites, especially among young children and pregnant women, a five-day course of pre-departure albendazole was effective in reducing helminthic infection in treated refugees.

Factors associated with nosocomial SARS-CoV transmission among healthcare workers in Hanoi, Vietnam, 2003.

BACKGROUND: In March of 2003, an outbreak of Severe Acute Respiratory Syndrome (SARS) occurred in Northern Vietnam. This outbreak began when a traveler arriving from Hong Kong sought medical care at a small hospital (Hospital A) in Hanoi, initiating a serious and substantial transmission event within the hospital, and subsequent limited spread within the community. METHODS: We surveyed Hospital A personnel for exposure to the index patient and for symptoms of disease during the outbreak. Additionally, serum specimens were collected and assayed for antibody to SARS-associated coronavirus (SARS-CoV) antibody and job-specific attack rates were calculated. A nested case-control analysis was performed to assess risk factors for acquiring SARS-CoV infection. RESULTS: One hundred and fifty-three of 193 (79.3%) clinical and non-clinical staff consented to participate. Excluding job categories with < 3 workers, the highest SARS attack rates occurred among nurses who worked in the outpatient and inpatient general wards (57.1, 47.4%, respectively). Nurses assigned to the operating room/intensive care unit, experienced the lowest attack rates (7.1%) among all clinical staff. Serologic evidence of SARS-CoV infection was detected in 4 individuals, including 2 non-clinical workers, who had not previously been identified as SARS cases; none reported having had fever or cough. Entering the index patient's room and having seen (viewed) the patient were the behaviors associated with highest risk for infection by univariate analysis (odds ratios 20.0, 14.0; 95% confidence intervals 4.1-97.1, 3.6-55.3, respectively). CONCLUSION: This study highlights job categories and activities associated with increased risk for SARS-CoV infection and demonstrates that a broad diversity of hospital workers may be vulnerable during an outbreak. These findings may help guide recommendations for the protection of vulnerable occupational groups and may have implications for other respiratory infections such as influenza.

Rapid malaria screening and targeted treatment of United States-bound Montagnard refugees from Cambodia in 2002.

In 2002, a group of Montagnard refugees living in Cambodia was accepted for resettlement in the United States. Pre-departure malaria screening and targeted treatment was conducted to prevent morbidity, and minimize the potential for local malaria transmission post-arrival. We screened 902 of 906 refugees using rapid diagnostic tests (RDTs), microscopy, and polymerase chain reaction (PCR) analysis. Twelve (1.3%) RDT results were positive and 28 (3.1%) were indeterminate. Microscopy confirmed Plasmodium species in two of the positive RDT and one of the indeterminate results. Among a random 10% sample of negative RDT results (n = 86), none were positive by microscopy. The PCR confirmed the two microscopically (and RDT) positive specimens. The PCR result was negative for all other specimens tested. Eighteen (2.0%) refugees were treated with antimalarials. The RDTs were useful in this setting, facilitating timely, sensitive diagnosis and targeted treatment. Evaluations to determine the most appropriate interventions in other refugee settings should include cost-effectiveness analyses of alternative strategies.