SARS-CoV-2 outbreak among staff and evacuees at Operation Allies Welcome Safe Havens

We report on five SARS-CoV-2 congregate setting outbreaks at U.S. Operation Allies Welcome Safe Havens/military facilities. Outbreak data were collected, and attack rates were calculated for various populations. Even in vaccinated populations, there was rapid spread, illustrating the importance of institutional prevention and mitigation policies in congregate settings.

Severe Acute Respiratory Syndrome Coronavirus 2 Prevalence, Seroprevalence, and Exposure among Evacuees from Wuhan, China, 2020

To determine prevalence of, seroprevalence of, and potential exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among a cohort of evacuees returning to the United States from Wuhan, China, in January 2020, we conducted a cross-sectional study of quarantined evacuees from 1 repatriation flight. Overall, 193 of 195 evacuees completed exposure surveys and submitted upper respiratory or serum specimens or both at arrival in the United States. Nearly all evacuees had taken preventive measures to limit potential exposure while in Wuhan, and none had detectable SARS-CoV-2 in upper respiratory tract specimens, suggesting the absence of asymptomatic respiratory shedding among this group at the time of testing. Evidence of antibodies to SARS-CoV-2 was detected in 1 evacuee, who reported experiencing no symptoms or high-risk exposures in the previous 2 months. These findings demonstrated that this group of evacuees posed a low risk of introducing SARS-CoV-2 to the United States.

Economic Analysis of the Impact of Overseas and Domestic Treatment and Screening Options for Intestinal Helminth Infection among US-Bound Refugees from Asia

BACKGROUND

Many U.S.-bound refugees travel from countries where intestinal parasites (hookworm, Trichuris trichuria, Ascaris lumbricoides, and Strongyloides stercoralis) are endemic. These infections are rare in the United States and may be underdiagnosed or misdiagnosed, leading to potentially serious consequences. This evaluation examined the costs and benefits of combinations of overseas presumptive treatment of parasitic diseases vs. domestic screening/treating vs. no program.

METHODS

An economic decision tree model terminating in Markov processes was developed to estimate the cost and health impacts of four interventions on an annual cohort of 27,700 U.S.-bound Asian refugees: 1) "No Program," 2) U.S. "Domestic Screening and Treatment," 3) "Overseas Albendazole and Ivermectin" presumptive treatment, and 4) "Overseas Albendazole and Domestic Screening for Strongyloides". Markov transition state models were used to estimate long-term effects of parasitic infections. Health outcome measures (four parasites) included outpatient cases, hospitalizations, deaths, life years, and quality-adjusted life years (QALYs).

RESULTS

The "No Program" option is the least expensive ($165,923 per cohort) and least effective option (145 outpatient cases, 4.0 hospitalizations, and 0.67 deaths discounted over a 60-year period for a one-year cohort). The "Overseas Albendazole and Ivermectin" option ($418,824) is less expensive than "Domestic Screening and Treatment" ($3,832,572) or "Overseas Albendazole and Domestic Screening for Strongyloides" ($2,182,483). According to the model outcomes, the most effective treatment option is "Overseas Albendazole and Ivermectin," which reduces outpatient cases, deaths and hospitalization by around 80% at an estimated net cost of $458,718 per death averted, or $2,219/$24,036 per QALY/life year gained relative to "No Program".

DISCUSSION

Overseas presumptive treatment for U.S.-bound refugees is a cost-effective intervention that is less expensive and at least as effective as domestic screening and treatment programs. The addition of ivermectin to albendazole reduces the prevalence of chronic strongyloidiasis and the probability of rare, but potentially fatal, disseminated strongyloidiasis.

CDC's Early Response to a Novel Viral Disease, Middle East Respiratory Syndrome Coronavirus (MERS-CoV), September 2012-May 2014

The first ever case of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) was reported in September 2012. This report describes the approaches taken by CDC, in collaboration with the World Health Organization (WHO) and other partners, to respond to this novel virus, and outlines the agency responses prior to the first case appearing in the United States in May 2014. During this time, CDC's response integrated multiple disciplines and was divided into three distinct phases: before, during, and after the initial activation of its Emergency Operations Center. CDC's response to MERS-CoV required a large effort, deploying at least 353 staff members who worked in the areas of surveillance, laboratory capacity, infection control guidance, and travelers' health. This response built on CDC's experience with previous outbreaks of other pathogens and provided useful lessons for future emerging threats.

Management of latent Mycobacterium tuberculosis infection: WHO guidelines for low tuberculosis burden countries

Latent tuberculosis infection (LTBI) is characterised by the presence of immune responses to previously acquired Mycobacterium tuberculosis infection without clinical evidence of active tuberculosis (TB). Here we report evidence-based guidelines from the World Health Organization for a public health approach to the management of LTBI in high risk individuals in countries with high or middle upper income and TB incidence of <100 per 100 000 per year. The guidelines strongly recommend systematic testing and treatment of LTBI in people living with HIV, adult and child contacts of pulmonary TB cases, patients initiating anti-tumour necrosis factor treatment, patients receiving dialysis, patients preparing for organ or haematological transplantation, and patients with silicosis. In prisoners, healthcare workers, immigrants from high TB burden countries, homeless persons and illicit drug users, systematic testing and treatment of LTBI is conditionally recommended, according to TB epidemiology and resource availability. Either commercial interferon-gamma release assays or Mantoux tuberculin skin testing could be used to test for LTBI. Chest radiography should be performed before LTBI treatment to rule out active TB disease. Recommended treatment regimens for LTBI include: 6 or 9 month isoniazid; 12 week rifapentine plus isoniazid; 3-4 month isoniazid plus rifampicin; or 3-4 month rifampicin alone.

Safety profile of smallpox vaccine: insights from the laboratory worker smallpox vaccination program

BACKGROUND

The frequency of mild-to-moderate adverse events following smallpox vaccination was not well documented or reported during the pre-eradication era. This report describes the frequency of such symptoms among 936 adult smallpox vaccinees with and without a history of prior smallpox vaccination.

METHODS

Diary cards were distributed to 1006 laboratory workers and members of the Centers for Disease Control and Prevention (CDC) smallpox response team who received smallpox vaccination under an investigational new drug protocol during 2001-2002. Vaccinees were requested to complete the diary card daily and return it to the CDC 28 days after vaccination. The proportion of vaccinees reporting symptoms was determined and compared among subgroups.

RESULTS

Ninety-three percent of the diary cards were returned. The most common symptom reported was "itching at vaccination site." Primary vaccines reported statistically higher proportions of the following 11 symptoms: joint pain (25% vs. 11%; P=.0011), muscle pain (46% vs. 19%; P<.0001), fatigue (43% vs. 29%; P=.0161), swelling at vaccination site (58% vs. 33%; P<.0001), itching on the body (31% vs. 17%; P=.0048), abdominal pain (11% vs. 2%; P=.0012), swollen or tender lymph nodes (71% vs. 33%; P<.0001), pain at injection site (48% vs. 30%; P=.0018), headache (40% vs. 25%; P=.0088), backache (17% vs. 7%; P=.0090), and fever (temperature, >or=100 degrees F [37.7 degrees C]; 20% vs. 9%; P=.0047).

CONCLUSIONS

This analysis suggests that previously unvaccinated persons aged <30 years experienced more symptoms than did previously vaccinated persons. The findings of increased proportions with joint pain, abdominal pain, backache, and difficulty breathing were unexpected. As with recently described cardiac adverse events, these symptoms are suggestive of systemic involvement and warrant further study.

Development and Experience with an Algorithm to Evaluate Suspected Smallpox Cases in the United States, 2002-2004

Concerns that smallpox, an eradicated disease, might reappear because of a bioterror attack and limited experience with smallpox diagnosis in the United States prompted us to design a clinical algorithm. We used clinical features of classic smallpox to classify persons presenting with suspected smallpox rashes into 3 categories: those with high, those with moderate, and those with low risk of having smallpox. The classification guides subsequent diagnostic strategies, limiting smallpox laboratory testing to high-risk persons to minimize the number of false-positive test results. From January 2002 through June 2004, the Centers for Disease Control and Prevention (CDC) received 43 consultations regarding suspected smallpox cases. No patient was at high risk for having smallpox. One patient was tested for the presence of variola virus. Varicella was the diagnosis for 23 cases (53%). The algorithm worked well to guide clinical and public health responses to suspected smallpox cases. The poster is available from CDC, and an interactive version and laboratory protocol are available at http://www.bt.cdc.gov/agent/smallpox/diagnosis/riskalgorithm/index.asp. We recommend use of the algorithm in the United States and elsewhere.

An epidemiologic and entomologic investigation of a cluster of Rocky Mountain spotted fever cases in Delaware

BACKGROUND

Rocky Mountain spotted fever (RMSF) continues to be the most common fatal tick-borne illness in the United States. In August of 1996, four children attending a summer camp in Delaware were diagnosed with RMSF. This report summarizes the results of the epidemiologic and entomologic investigation conducted by the Delaware Division of Public Health and the Centers for Disease Control and Prevention regarding this cluster of RMSF cases. Epidemiologic and clinical aspects of RMSF, as well as previously reported clusters of the disease, are also reviewed.

METHODS

A questionnaire regarding symptoms and activities was administered via telephone to 163 (73 percent) of the 223 attendees. A suspected case was defined as an illness in a person attending the camp between August 11 and 17 that occurred during the two-week period following the session, characterized by either 1) fever with one or more symptoms (i.e., headache, rash, myalgia, or fatigue) or 2) no fever with two or more symptoms. Cases of RMSF were confirmed by serologic evaluation.

RESULTS

Seven of 13 patients with suspected RMSF submitted sera for testing. Four patients had confirmed RMSF; three were males, and the median age was 12.5 years compared with 12 years for all attendees. All confirmed patients reported fever, headache, fatigue, and rash. An increased risk of becoming ill was associated with overnight camping at site A (Odds Ratio (OR) undefined, p = 0.02), visiting or overnight camping at site B (OR undefined, p = 0.003 and 0.002), and leaving the trails when hiking (OR undefined, p = 0.02).

CONCLUSIONS

These data suggest that development of RMSF was associated with visiting or camping at specific sites and behavior likely to increase contact with ticks. Camp supervisors were advised to educate campers regarding tick bite prevention measures, reduce underbrush around campsites, and encourage campers to remain on the trails. Health care providers should remain aware of the increased risk for RMSF during the spring, summer, and fall months.