Cross-Sectional Assessment of the Association of Eosinophilia with Intestinal Parasitic Infection in U.S.-Bound Refugees in Thailand: Prevalent, Age Dependent, but of Limited Clinical Utility.

The most common causes of eosinophilia globally are helminth parasites. Refugees from high endemic areas are at increased risk of infection compared with the general U.S. population. It is widely accepted that eosinophilia is a good marker for helminth infection in this population, yet its absence has little predictive value for excluding infection. During an enhanced premigration health program, the CDC offered voluntary testing and management of intestinal parasites, among other conditions, to U.S.-bound refugees in Thailand. Stool specimens were tested for Ascaris lumbricoides, Strongyloides stercoralis, Trichuris trichiura, hookworms, Giardia lamblia, Cryptosporidium spp., and Entamoeba histolytica using quantitative polymerase chain reaction. Complete blood counts were performed to identify eosinophilia. Predictive values of eosinophilia for parasitic infections were calculated within nematode groups. Between July 9, 2012 and November 29, 2013, 2,004 participants were enrolled. About 73% were infected with at least one parasite. The overall median eosinophil count was 483 cells/µL (interquartile range [IQR] = 235-876 cells/µL). Compared with participants who did not test positive for any infection, higher eosinophil counts were observed in those infected with A. lumbricoides (RR = 1.3, 95% CI = 1.1-1.4), S. stercoralis (RR = 1.8, 95% CI = 1.4-2.4), Necator americanus (RR = 1.2, 95% CI = 1.1-1.4), and Ancylostoma ceylanicum (RR = 1.8, 95% CI = 1.5-2.2). Eosinophil counts were higher in younger participants (2-4 years versus 65+ years: RR = 4.2, 95% CI = 2.5-6.9), and lower in female participants (RR = 0.9, 95% CI = 0.8-0.9). Sensitivities ranged from 51% to 73%, specificities from 48% to 65%, and predictive values from 4% to 98%. The predictive value of eosinophilia is poor for the most common parasitic infections, and it should not be used alone for screening refugees.

Disease Surveillance Among U.S.-Bound Immigrants and Refugees - Electronic Disease Notification System, United States, 2014-2019.

PROBLEM/CONDITION: Each year, approximately 500,000 immigrants and tens of thousands of refugees (range: 12,000-85,000 during 2001-2020) move to the United States. While still abroad, immigrants, refugees, and others who apply for admission to live permanently in the United States must undergo a medical examination. This examination identifies persons with class A or B conditions. Applicants with class A conditions are inadmissible. Infectious conditions that cause an applicant to be inadmissible include infectious tuberculosis (TB) disease (class A TB), infectious syphilis, gonorrhea, and infectious Hansen's disease. Applicants with class B conditions are admissible but might require treatment or follow-up. Class B TB includes persons who completed successful treatment overseas for TB disease (class B0), those with signs or symptoms suggestive of TB but whose overseas laboratory tests and clinical examinations ruled out current infectious TB disease (class B1), those with a diagnosis of latent TB infection (LTBI) (class B2), and the close contacts of persons known to have TB disease (class B3). Voluntary public health interventions might also be offered during the overseas examination. After arriving in the United States, a follow-up TB examination is recommended for persons with class B TB. PERIOD COVERED: This report summarizes health information that was reported to CDC's Electronic Disease Notification (EDN) system for refugees, immigrants, and eligible others who arrived in the United States during 2014-2019. Eligible others are persons who although not classified as refugees (e.g., certain parolees, special immigrant visa holders, and follow-to-join asylees) are eligible for the same services and benefits as refugees. DESCRIPTION OF SYSTEM: The EDN system has both surveillance and programmatic components. The surveillance component is a centralized database that collects 1) health-related data from the overseas medical examination for immigrants with class A or B conditions and for all refugees and eligible others and 2) TB-related data from the postarrival TB examination. The programmatic component is a reporting system that sends arrival notifications to state and local health agencies in the jurisdiction where newly arriving persons have reported intending to live and provides state and local health agencies and other authorized users with medical data from overseas examinations. RESULTS: During 2014-2019, approximately 3.5 million persons moved to the United States from abroad, including 3.2 million immigrants, 313,890 refugees, and 95,993 eligible others. Among these, the overseas examination identified 139,683 persons (3,903 per 100,000 persons examined) with class B TB, 54 with primary or secondary syphilis (30 per 100,000 persons tested), 761 with latent syphilis (415 per 100,000 persons tested), and, after laboratory testing for gonorrhea was added in 2016, a total of 131 with gonorrhea (374 per 100,000 persons tested). Refugees were offered additional, voluntary interventions, including vaccinations and presumptive treatment for parasites. By 2019, first- and second-dose coverage with measles-containing vaccine were 96% and 80%, respectively. In refugee populations for whom presumptive treatment is recommended, up to 96% of refugees, depending on the specific regimen, were offered and accepted treatment. For the 139,683 persons identified overseas with class B TB, EDN sent arrival notifications and overseas medical data to the appropriate state or local health agency to facilitate postarrival TB examinations. Among 101,119 persons identified overseas as having class B0 TB (6,586) or class B1 TB (94,533), a total of 67,432 (67%) had a complete postarrival examination reported to EDN. Among 35,814 children aged 2-14 years identified overseas with class B2 TB, 20,758 (58%) had a complete postarrival examination reported to EDN. (Adults are not routinely tested for immune reactivity to Mycobacterium tuberculosis during the overseas medical examination.) Among those with a complete postarrival examination reported to EDN, the number with a diagnosis of culture-positive TB disease within the first year of arrival was 464 (688 cases per 100,000 persons examined) for those with class B0 or B1 TB and was 11 (53 cases per 100,000 persons examined) for children with class B2 TB. INTERPRETATION: During 2014-2019, the overseas medical examination system prevented importation of 6,586 cases of infectious TB, 815 cases of syphilis, and 131 cases of gonorrhea. When the examination is used to offer public health interventions, most refugees (up to 96%) accept the intervention. Postarrival follow-up examinations, which were completed for 88,190 persons and identified 475 cases of culture-positive TB, represent an important opportunity to further limit spread of TB disease in the United States by identifying and providing, if needed, preventive care for those with LTBI or treatment for those with disease. PUBLIC HEALTH ACTION: Federal, state, and local health departments and agencies should continue to use EDN data to monitor, evaluate, and improve health-related programs and policies aimed at U.S.-bound or recently arrived immigrants, refugees, and eligible others. Additional public health interventions that could be offered during the overseas medical examination should be considered (e.g., treatment for LTBI). Finally, for persons with class B TB, measures should be taken to identify and remove barriers to completing postarrival examinations to reduce risk for TB disease and community transmission, along with measures to encourage reporting of completed examinations for better data-driven decision-making.

An immunization program for US-bound refugees: Development, challenges, and opportunities 2012-present.

BACKGROUND: US-bound refugees undergo required health assessments overseas to identify and treat communicable diseases of public health significance-such as pulmonary tuberculosis-before migration. Immunizations are not required, leaving refugees at risk for vaccine-preventable diseases. In response, the US Centers for Disease Control and Prevention and the US Department of State developed and co-funded a global immunization program for US-bound refugees, implemented in 2012 in collaboration with the International Organization for Migration. METHODS: We describe the Vaccination Program for US-bound Refugees, including vaccination schedule development, program implementation and procedures, and responses to challenges. We estimate 2019 immunization coverage rates using the number of age-eligible refugees who received ≥1 dose of measles-containing vaccine during overseas health assessment, and calculated hepatitis B infection prevalence using hepatitis B surface antigen testing results. We report descriptive data on adverse events following immunization. RESULTS: By September 2019, the program was active in >80 countries on five continents. Nearly 320,000 examined refugees had ≥1 documented vaccine doses since program inception. During federal fiscal year 2019, 95% of arriving refugees had ≥1 documented measles-containing vaccine. The program's immunization schedule included eleven vaccines preventing fourteen diseases. In 2015-2019, only two vaccine preventable disease-associated refugee group travel cancellations occurred, compared to 2-8 cancellations annually prior to program initiation. To maintain uniform standards, dedicated staff and program-specific protocols for vaccination and monitoring were introduced. CONCLUSIONS: An overseas immunization program was successfully implemented for US-bound refugees. Due to reductions in refugee movement cancellation, lower cost of immunization overseas, and likely reductions in vaccine preventable disease-associated morbidity, we anticipate significant cost savings. Although maintaining uniform standards across diverse settings is challenging, solutions such as introduction of dedicated staff, protocol development, and ongoing technical support have ensured program cohesion, continuity, and advancement. Lessons learned can benefit similar programs implemented in the migration setting.

Nutritional profile of Syrian refugee children before resettlement.

BACKGROUND: The year 2015 marked the highest number of refugees globally and included record numbers of Syrians moving to neighboring countries. Half of the Syrians were children aged ≤18 years. Our study sought to examine undernutrition and overnutrition among a group of Syrian refugee children who underwent medical screening by IOM for resettlement. METHODS: This is a retrospective review of Syrian refugee children aged 6 to 59 months from January 1, 2015 to December 31, 2016. The World Health Organization (WHO) Stata package computed Z-scores based on available weight and height data. Prevalence estimates of undernutrition (wasting and stunting) and overnutrition (overweight and obesity) were made using WHO standards. Multivariate analysis was used to determine the factors associated with wasting, stunting, and overnutrition, adjusting for age, sex, family size, and country of health assessment. RESULTS: A total of 14,552 Syrian refugee children aged 6 to 59 months underwent health assessments in Jordan (43·1%), Lebanon (38·8%), Turkey (7·0%), Greece (6·7%), Egypt (2·4%), and Iraq (2·1%). Overall, this group of Syrian refugee children had a low prevalence of wasting (< 5%) and stunting (< 10%), and high prevalence of overweight or obese (10.6%). Differences were observed in the prevalence of wasting by country of health assessment. In the multiple regression analysis, the prevalence of stunting and overnutrition decreased with increasing age, and being male was associated with overnutrition but not wasting and stunting. CONCLUSIONS: Findings revealed an overall low prevalence of undernutrition among this group of Syrian children assessed, although prevalence varied by age group. This low prevalence may reflect the effectiveness, as well as expose possible gaps, of refugee nutrition programs or interventions in countries of asylum. Further studies are recommended to evaluate other possible contributors to malnutrition in this refugee group.

Immigrant and Refugee Health: A Centers for Disease Control and Prevention Perspective on Protecting the Health and Health Security of Individuals and Communities During Planned Migrations.

Migration and forced displacement are at record levels in today's geopolitical environment; ensuring the health of migrating populations and the health security of asylum and receiving countries is critically important. Overseas screening, treatment, and vaccination during planned migration to the United States represents one successful model. These strategies have improved tuberculosis detection and treatment, reducing rates in the United States; decreased transmission and importation of vaccine-preventable diseases; prevented morbidity and mortality from parasitic diseases among refugees; and saved health costs. We describe the work of CDC's Division of Global Migration and Quarantine and partners in developing and implementing these strategies.

Blood Lead Levels Among Resettled Refugee Children in Select US States, 2010-2014.

BACKGROUND: Elevated blood lead levels (EBLLs; ≥5 µg/dL) are more prevalent among refugee children resettled in the United States than the general US population and contribute to permanent health and neurodevelopmental problems. The Centers for Disease Control and Prevention recommends screening of refugee children aged 6 months to 16 years on arrival in the United States and retesting those aged 6 months to 6 years between 3- and 6-months postarrival. METHODS: We analyzed EBLL prevalence among refugee children aged 6 months to 16 years who received a domestic refugee medical examination between January 1, 2010 and September 30, 2014. We assessed EBLL prevalence by predeparture examination country and, among children rescreened 3 to 6 months after initial testing, we assessed EBLL changes during follow-up screening. RESULTS: Twelve sites provided data on 27 284 children representing nearly 25% of refugee children resettling during the time period of this analysis. The EBLL prevalence during initial testing was 19.3%. EBLL was associated with younger age, male sex, and overseas examination country. Among 1121 children from 5 sites with available follow-up test results, EBLL prevalence was 22.7%; higher follow-up BLLs were associated with younger age and predeparture examination country. CONCLUSIONS: EBLL decreased over the time period of our analysis in this population of refugee children. Refugee children may be exposed to lead before and after resettlement to the United States. Efforts to identify incoming refugee populations at high risk for EBLL can inform prevention efforts both domestically and overseas.

Ancylostoma ceylanicum Hookworm in Myanmar Refugees, Thailand, 2012-2015.

During 2012-2015, US-bound refugees living in Myanmar-Thailand border camps (n = 1,839) were surveyed for hookworm infection and treatment response by using quantitative PCR. Samples were collected at 3 time points: after each of 2 treatments with albendazole and after resettlement in the United States. Baseline prevalence of Necator americanus hookworm was 25.4%, Ancylostoma duodenale 0%, and Ancylostoma ceylanicum (a zoonosis) 5.4%. Compared with N. americanus prevalence, A. ceylanicum hookworm prevalence peaked in younger age groups, and blood eosinophil concentrations during A. ceylanicum infection were higher than those for N. americanus infection. Female sex was associated with a lower risk for either hookworm infection. Cure rates after 1 dose of albendazole were greater for A. ceylanicum (93.3%) than N. americanus (65.9%) hookworm (p<0.001). Lower N. americanus hookworm cure rates were unrelated to ß-tubulin single-nucleotide polymorphisms at codons 200 or 167. A. ceylanicum hookworm infection might be more common in humans than previously recognized.

A comparative cost analysis of the Vaccination Program for US-bound Refugees.

BACKGROUND: Vaccination Program for US-bound Refugees (VPR) currently provides one or two doses of some age-specific Advisory Committee on Immunization Practices (ACIP)-recommended vaccines to US-bound refugees prior to departure. METHODS: We quantified and compared the full vaccination costs for refugees using two scenarios: (1) the baseline of no VPR and (2) the current situation with VPR. Under the first scenario, refugees would be fully vaccinated after arrival in the United States. For the second scenario, refugees would receive one or two doses of selected vaccines before departure and complete the recommended vaccination schedule after arrival in the United States. We evaluated costs for the full vaccination schedule and for the subset of vaccines provided by VPR by four age-stratified groups; all costs were reported in 2015 US dollars. We performed one-way and probabilistic sensitivity analyses and break-even analyses to evaluate the robustness of results. RESULTS: Vaccination costs with the VPR scenario were lower than costs of the scenario without the VPR for refugees in all examined age groups. Net cost savings per person associated with the VPR were ranged from $225.93 with estimated Refugee Medical Assistance (RMA) or Medicaid payments for domestic costs to $498.42 with estimated private sector payments. Limiting the analyses to only the vaccines included in VPR, the average costs per person were 56% less for the VPR scenario with RMA/Medicaid payments. Net cost savings with the VPR scenario were sensitive to inputs for vaccination costs, domestic vaccine coverage rates, and revaccination rates, but the VPR scenario was cost savings across a range of plausible parameter estimates. CONCLUSIONS: VPR is a cost-saving program that would also reduce the risk of refugees arriving while infected with a vaccine preventable disease.

Impact of Enhanced Health Interventions for United States-Bound Refugees: Evaluating Best Practices in Migration Health.

With an unprecedented number of displaced persons worldwide, strategies for improving the health of migrating populations are critical. United States-bound refugees undergo a required overseas medical examination to identify inadmissible conditions (e.g., tuberculosis) 2-6 months before resettlement, but it is limited in scope and may miss important, preventable infectious, chronic, or nutritional causes of morbidity. We sought to evaluate the feasibility and health impact of diagnosis and management of such conditions before travel. We offered voluntary testing for intestinal parasites, anemia, and hepatitis B virus infection, to U.S.-bound refugees from three Thailand-Burma border camps. Treatment and preventive measures (e.g., anemia and parasite treatment, vaccination) were initiated before resettlement. United States refugee health partners received overseas results and provided post-arrival medical examination findings. During July 9, 2012 to November 29, 2013, 2,004 refugees aged 0.5-89 years enrolled. Among 463 participants screened for seven intestinal parasites overseas and after arrival, helminthic infections decreased from 67% to 12%. Among 118 with positive Strongyloides-specific antibody responses, the median fluorescent intensity decreased by an average of 81% after treatment. The prevalence of moderate-to-severe anemia (hemoglobin < 10 g/dL) was halved from 14% at baseline to 7% at departure (McNemar P = 0.001). All 191 (10%) hepatitis B-infected participants received counseling and evaluation; uninfected participants were offered vaccination. This evaluation demonstrates that targeted screening, treatment, and prevention services can be conducted during the migration process to improve the health of refugees before resettlement. With more than 250 million migrants globally, this model may offer insights into healthier migration strategies.

Cost analysis of measles in refugees arriving at Los Angeles International Airport from Malaysia.

Background On August 24, 2011, 31 US-bound refugees from Kuala Lumpur, Malaysia (KL) arrived in Los Angeles. One of them was diagnosed with measles post-arrival. He exposed others during a flight, and persons in the community while disembarking and seeking medical care. As a result, 9 cases of measles were identified. Methods We estimated costs of response to this outbreak and conducted a comparative cost analysis examining what might have happened had all US-bound refugees been vaccinated before leaving Malaysia. Results State-by-state costs differed and variously included vaccination, hospitalization, medical visits, and contact tracing with costs ranging from $621 to $35,115. The total of domestic and IOM Malaysia reported costs for US-bound refugees were $137,505 [range: $134,531 - $142,777 from a sensitivity analysis]. Had all US-bound refugees been vaccinated while in Malaysia, it would have cost approximately $19,646 and could have prevented 8 measles cases. Conclusion A vaccination program for US-bound refugees, supporting a complete vaccination for US-bound refugees, could improve refugees' health, reduce importations of vaccine-preventable diseases in the United States, and avert measles response activities and costs.

Cost-benefit comparison of two proposed overseas programs for reducing chronic Hepatitis B infection among refugees: is screening essential?

BACKGROUND: Refugees are at an increased risk of chronic Hepatitis B virus (HBV) infection because many of their countries of origin, as well as host countries, have intermediate-to-high prevalence rates. Refugees arriving to the US are also at risk of serious sequelae from chronic HBV infection because they are not routinely screened for the virus overseas or in domestic post-arrival exams, and may live in the US for years without awareness of their infection status. METHODS: A cohort of 26,548 refugees who arrived in Minnesota and Georgia during 2005-2010 was evaluated to determine the prevalence of chronic HBV infection. This prevalence information was then used in a cost-benefit analysis comparing two variations of a proposed overseas program to prevent or ameliorate the effects of HBV infection, titled 'Screen, then vaccinate or initiate management' (SVIM) and 'Vaccinate only' (VO). The analyses were performed in 2013. All values were converted to US 2012 dollars. RESULTS: The estimated six year period-prevalence of chronic HBV infection was 6.8% in the overall refugee population arriving to Minnesota and Georgia and 7.1% in those ≥6 years of age. The SVIM program variation was more cost beneficial than VO. While the up-front costs of SVIM were higher than VO ($154,084 vs. $73,758; n=58,538 refugees), the SVIM proposal displayed a positive net benefit, ranging from $24 million to $130 million after only 5 years since program initiation, depending on domestic post-arrival screening rates in the VO proposal. CONCLUSIONS: Chronic HBV infection remains an important health problem in refugees resettling to the United States. An overseas screening policy for chronic HBV infection is more cost-beneficial than a 'Vaccination only' policy. The major benefit drivers for the screening policy are earlier medical management of chronic HBV infection and averted lost societal contributions from premature death.

Seroprevalence of varicella-zoster virus in five US-bound refugee populations.

Little is known about varicella-zoster virus (VZV) susceptibility in US-bound refugee populations, although published data suggest that VZV seroprevalence in these refugee populations may be lower than US populations. We describe VZV seroprevalence in five US-bound refugee groups: (1) Bhutanese in Nepal, (2) Burmese on the Thailand-Burma (Myanmar) border, (3) Burmese in Malaysia, (4) Iraqi in Jordan, and (5) Somali in Kenya. Sera were tested for presence of VZV IgG antibodies among adults aged 18-45 years. Overall VZV seroprevalence was 97% across all refugee groups. VZV seroprevalence was also high across all age groups, with seroprevalence ranging from 92-100% for 18-26 year-olds depending on refugee group and 93-100% for 27-45 year-olds. VZV seroprevalence was unexpectedly high in these five US-bound refugee groups, though may not reflect seroprevalence in other refugee groups. Additional studies are needed to better understand VZV seroprevalence in refugee populations over time and by region.

Swine flu in college: early campus response to outbreak control measures.

OBJECTIVES: To describe student and faculty attitudes towards and adherence to nonpharmaceutical control measures during the first-known university outbreak of 2009 pandemic influenza A (H1N1). METHODS: Preferred information sources, control measure adherence and likelihood of adherence during future out-breaks, and perceived illness risk, were explored through focus groups and patient interviews. RESULTS: We conducted 7 focus groups (N=48) and 9 patient inter- views. Measures (eg, hand hygiene, self-isolation while ill) were initially heeded. Limited information regarding A(H1N1) pdm09, insufficient understanding of university decisions, and perceived university alert overuse led to reports that future outbreaks would be regarded less seriously. CONCLUSIONS: Reported concern and commitment to recommendations decreased rapidly. Initial university messaging and response was critical in shaping participants' later perceptions.

Nutritional status of refugee children entering DeKalb County, Georgia.

This study determines the nutritional status among refugee children entering one of the largest resettlement counties in the United States and identifies differences between incoming populations. Medical records of all newly arriving pediatric refugees (0-18 years) entering DeKalb County, Georgia between October 2010 and July 2011 were reviewed. Refugee children were grouped as African, Bhutanese, or Burmese (resettling from either Thailand or Malaysia) for comparative analysis. Approximately one in five refugees were anemic or malnourished, while a quarter had stool parasites, and nearly half had dental caries. African refugees had the highest anemia but the lowest underweight prevalence (p < 0.05). Compared to Burmese resettling from Malaysia, Burmese children from Thailand had a higher prevalence of anemia, underweight, and stool parasites (p < 0.05). Clinicians should use CDC medical screening guidelines for newly arriving pediatric refugees, as well as ensure proper nutritional support and follow-up care.

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

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

Lead poisoning in United States-bound refugee children: Thailand-Burma border, 2009.

BACKGROUND: Elevated blood lead levels lead to permanent neurocognitive sequelae in children. Resettled refugee children in the United States are considered at high risk for elevated blood lead levels, but the prevalence of and risk factors for elevated blood lead levels before resettlement have not been described. METHODS: Blood samples from children aged 6 months to 14 years from refugee camps in Thailand were tested for lead and hemoglobin. Sixty-seven children with elevated blood lead levels (venous ≥10 µg/dL) or undetectable (capillary <3.3 µg/dL) blood lead levels participated in a case-control study. RESULTS: Of 642 children, 33 (5.1%) had elevated blood lead levels. Children aged <2 years had the highest prevalence (14.5%). Among children aged <2 years included in a case-control study, elevated blood lead levels risk factors included hemoglobin <10 g/dL, exposure to car batteries, and taking traditional medicines. CONCLUSIONS: The prevalence of elevated blood lead levels among tested US-bound Burmese refugee children was higher than the current US prevalence, and was especially high among children <2 years old. Refugee children may arrive in the United States with elevated blood lead levels. A population-specific understanding of preexisting lead exposures can enhance postarrival lead-poisoning prevention efforts, based on Centers for Disease Control and Prevention recommendations for resettled refugee children, and can lead to remediation efforts overseas.

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.

Transmission of 2009 pandemic influenza A (H1N1) at a Public University--Delaware, April-May 2009.

We investigated the first documented university outbreak of the 2009 pandemic influenza A(H1N1) to identify factors associated with disease transmission. An online student survey was administered to assess risk factors for influenza-like illness (ILI), defined as fever with cough or sore throat. Of 6049 survey respondents, 567 (9%) experienced ILI during 27 March to 9 May 2009. Studying with an ill contact (adjusted risk ratios [aRR], 1.29; 95% confidence intervals [CI], 1.01-1.65) and caring for an ill contact (aRR, 1.51; CI, 1.14-2.01) any time during 27 March to 9 May were predictors for ILI. Respondents reported that 680 (6%) of 11,411 housemates were ill; living with an ill housemate was a predictor for ILI (RR, 1.38; CI, 1.04-1.83). Close contact or prolonged exposures to ill persons were likely associated with experiencing ILI. Self-protective measures should be promoted in university populations to mitigate transmission.

Non-pharmaceutical interventions during an outbreak of 2009 pandemic influenza A (H1N1) virus infection at a large public university, April-May 2009.

Nonpharmaceutical interventions (NPIs), such as home isolation, social distancing, and infection control measures, are recommended by public health agencies as strategies to mitigate transmission during influenza pandemics. However, NPI implementation has rarely been studied in large populations. During an outbreak of 2009 Pandemic Influenza A (H1N1) virus infection at a large public university in April 2009, an online survey was conducted among students, faculty, and staff to assess knowledge of and adherence to university-recommended NPI. Although 3924 (65%) of 6049 student respondents and 1057 (74%) of 1401 faculty respondents reported increased use of self-protective NPI, such as hand washing, only 27 (6.4%) of 423 students and 5 (8.6%) of 58 faculty with acute respiratory infection (ARI) reported staying home while ill. Nearly one-half (46%) of student respondents, including 44.7% of those with ARI, attended social events. Results indicate a need for efforts to increase compliance with home isolation and social distancing measures.

Investigating 2009 pandemic influenza A (H1N1) in US schools: what have we learned?

US investigations of school-based outbreaks of 2009 pandemic influenza A (H1N1) virus infection characterized influenza-like illness (ILI) attack rates, transmission risk factors, and adherence to nonpharmaceutical interventions. We summarize seven school-based investigations conducted during April-June 2009 to determine what questions might be answered by future investigations. Surveys were administered 5-28 days after identification of the outbreaks, and participation rates varied among households (39-86%) and individuals (24-49%). Compared with adults (4%-10%) and children aged <4 years (2%-7%), elementary through university students had higher ILI attack rates (4%-32%). Large gatherings or close contact with sick persons were identified as transmission risk factors. More participants reported adherence to hygiene measures, but fewer reported adherence to isolation measures. Challenges included low participation and delays in survey initiation that potentially introduced bias. Although school-based investigations can increase our understanding of epidemiology and prevention strategy effectiveness, investigators should decide which objectives are most feasible, given timing and design constraints.