Tarissa Mitchell

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.

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.

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.

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.

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.

Correction: The Increasing Burden of Imported Chronic Hepatitis B — United States, 1974–2008

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

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

Ancylostoma ceylanicum Hookworm in Myanmar Refugees, Thailand, 2012–2015

225.93 with estimated Refugee Medical Assistance (RMA) or Medicaid payments for domestic costs to

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

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.

Notes from the field: outbreak of 2009 pandemic influenza A (H1N1) virus at a large public university in Delaware, April-May 2009.

This hookworm, uncommonly found in humans, has a higher cure rate than that for Necator americanus hookworm.