Not all clusters are equal: dynamics of molecular HIV-1 clusters in a statewide Rhode Island epidemic

OBJECTIVES

Molecular epidemiology is a powerful tool to characterize HIV epidemics and prioritize public health interventions. Typically, HIV clusters are assumed to have uniform patterns over time. We hypothesized that assessment of cluster evolution would reveal distinct cluster behavior, possibly improving molecular epidemic characterization, towards disrupting HIV transmission.

DESIGN

Retrospective cohort.

METHODS

Annual phylogenies were inferred by cumulative aggregation of all available HIV-1 pol sequences of individuals with HIV-1 in Rhode Island (RI) between 1990 and 2020, representing a statewide epidemic. Molecular clusters were detected in annual phylogenies by strict and relaxed cluster definition criteria, and the impact of annual newly-diagnosed HIV-1 cases to the structure of individual clusters was examined over time.

RESULTS

Of 2153 individuals, 31% (strict criteria) - 47% (relaxed criteria) clustered. Longitudinal tracking of individual clusters identified three cluster types: normal, semi-normal and abnormal. Normal clusters (83-87% of all identified clusters) showed predicted growing/plateauing dynamics, with approximately three-fold higher growth rates in large (15-18%) vs. small (∼5%) clusters. Semi-normal clusters (1-2% of all clusters) temporarily fluctuated in size and composition. Abnormal clusters (11-16% of all clusters) demonstrated collapses and re-arrangements over time. Borderline values of cluster-defining parameters explained dynamics of non-normal clusters.

CONCLUSIONS

Comprehensive tracing of molecular HIV clusters over time in a statewide epidemic identified distinct cluster types, likely missed in cross-sectional analyses, demonstrating that not all clusters are equal. This knowledge challenges current perceptions of consistent cluster behavior over time and could improve molecular surveillance of local HIV epidemics to better inform public health strategies.

Beyond HIV outbreaks: protocol, rationale and implementation of a prospective study quantifying the benefit of incorporating viral sequence clustering analysis into routine public health interventions

INTRODUCTION

HIV continues to have great impact on millions of lives. Novel methods are needed to disrupt HIV transmission networks. In the USA, public health departments routinely conduct contact tracing and partner services and interview newly HIV-diagnosed index cases to obtain information on social networks and guide prevention interventions. Sequence clustering methods able to infer HIV networks have been used to investigate and halt outbreaks. Incorporation of such methods into routine, not only outbreak-driven, contact tracing and partner services holds promise for further disruption of HIV transmissions.

METHODS AND ANALYSIS

Building on a strong academic-public health collaboration in Rhode Island, we designed and have implemented a state-wide prospective study to evaluate an intervention that incorporates real-time HIV molecular clustering information with routine contact tracing and partner services. We present the rationale and study design of our approach to integrate sequence clustering methods into routine public health interventions as well as related important ethical considerations. This prospective study addresses key questions about the benefit of incorporating a clustering analysis triggered intervention into the routine workflow of public health departments, going beyond outbreak-only circumstances. By developing an intervention triggered by, and incorporating information from, viral sequence clustering analysis, and evaluating it with a novel design that avoids randomisation while allowing for methods comparison, we are confident that this study will inform how viral sequence clustering analysis can be routinely integrated into public health to support the ending of the HIV pandemic in the USA and beyond.

ETHICS AND DISSEMINATION

The study was approved by both the Lifespan and Rhode Island Department of Health Human Subjects Research Institutional Review Boards and study results will be published in peer-reviewed journals.

Statewide Longitudinal Trends in Transmitted HIV-1 Drug Resistance in Rhode Island, USA

Background

HIV-1 transmitted drug resistance (TDR) remains a global challenge that can impact care, yet its comprehensive assessment is limited and heterogenous. We longitudinally characterized statewide TDR in Rhode Island.

Methods

Demographic and clinical data from treatment-naïve individuals were linked to protease, reverse transcriptase, and integrase sequences routinely obtained over 2004-2020. TDR extent, trends, impact on first-line regimens, and association with transmission networks were assessed using the Stanford Database, Mann-Kendall statistic, and phylogenetic tools.

Results

In 1123 individuals, TDR to any antiretroviral increased from 8% (2004) to 26% (2020), driven by non-nucleotide reverse transcriptase inhibitor (NNRTI; 5%-18%) and, to a lesser extent, nucleotide reverse transcriptase inhibitor (NRTI; 2%-8%) TDR. Dual- and triple-class TDR rates were low, and major integrase strand transfer inhibitor resistance was absent. Predicted intermediate to high resistance was in 77% of those with TDR, with differential suppression patterns. Among all individuals, 34% were in molecular clusters, some only with members with TDR who shared mutations. Among clustered individuals, people with TDR were more likely in small clusters.

Conclusions

In a unique (statewide) assessment over 2004-2020, TDR increased; this was primarily, but not solely, driven by NNRTIs, impacting antiretroviral regimens. Limited TDR to multiclass regimens and pre-exposure prophylaxis are encouraging; however, surveillance and its integration with molecular epidemiology should continue in order to potentially improve care and prevention interventions.

Longitudinal typing of molecular HIV clusters in a statewide epidemic

BACKGROUND

HIV molecular epidemiology is increasingly integrated into public health prevention. We conducted cluster typing to enhance characterization of a densely sampled statewide epidemic towards informing public health.

METHODS

We identified HIV clusters, categorized them into types, and evaluated their dynamics between 2004 and 2019 in Rhode Island. We grouped sequences by diagnosis year, assessed cluster changes between paired phylogenies, t0 and t1, representing adjacent years and categorized clusters as stable (cluster in t0 phylogeny = cluster in t1 phylogeny) or unstable (cluster in t0 ≠ cluster in t1). Unstable clusters were further categorized as emerging (t1 phylogeny only) or growing (larger in t1 phylogeny). We determined proportions of each cluster type, of individuals in each cluster type, and of newly diagnosed individuals in each cluster type, and assessed trends over time.

RESULTS

A total of 1727 individuals with available HIV-1 subtype B pol sequences were diagnosed in Rhode Island by 2019. Over time, stable clusters and individuals in them dominated the epidemic, increasing over time, with reciprocally decreasing unstable clusters and individuals in them. Conversely, proportions of newly diagnosed individuals in unstable clusters significantly increased. Within unstable clusters, proportions of emerging clusters and of individuals in them declined; whereas proportions of newly diagnosed individuals in growing clusters significantly increased over time.

CONCLUSION

Distinct molecular cluster types were identified in the Rhode Island epidemic. Cluster dynamics demonstrated increasing stable and decreasing unstable clusters driven by growing, rather than emerging clusters, suggesting consistent in-state transmission networks. Cluster typing could inform public health beyond conventional approaches and direct interventions.

Low Seroprevalence of SARS-CoV-2 in Rhode Island blood donors during may 2020 as determined using multiple serological assay formats

BACKGROUND

Epidemic projections and public health policies addressing Coronavirus disease (COVID)-19 have been implemented without data reporting on the seroconversion of the population since scalable antibody testing has only recently become available.

METHODS

We measured the percentage of severe acute respiratory syndrome- Coronavirus-2 (SARS-CoV-2) seropositive individuals from 2008 blood donors drawn in the state of Rhode Island (RI). We utilized multiple antibody testing platforms, including lateral flow immunoassays (LFAs), enzyme-linked immunosorbent assays (ELISAs) and high throughput serological assays (HTSAs). To estimate seroprevalence, we utilized the Bayesian statistical method to adjust for sensitivity and specificity of the commercial tests used.

RESULTS

We report than an estimated seropositive rate of RI blood donors of approximately 0.6% existed in April-May of 2020. Daily new case rates peaked in RI in late April 2020. We found HTSAs and LFAs were positively correlated with ELISA assays to detect antibodies specific to SARS-CoV-2 in blood donors.

CONCLUSIONS

These data imply that seroconversion, and thus infection, is likely not widespread within this population. We conclude that IgG LFAs and HTSAs are suitable to conduct seroprevalence assays in random populations. More studies will be needed using validated serological tests to improve the precision and report the kinetic progression of seroprevalence estimates.

Low Seroprevalence of SARS-CoV-2 in Rhode Island blood donors during may 2020 as determined using multiple serological assay formats

BACKGROUND

Epidemic projections and public health policies addressing Coronavirus disease (COVID)-19 have been implemented without data reporting on the seroconversion of the population since scalable antibody testing has only recently become available.

METHODS

We measured the percentage of severe acute respiratory syndrome- Coronavirus-2 (SARS-CoV-2) seropositive individuals from 2008 blood donors drawn in the state of Rhode Island (RI). We utilized multiple antibody testing platforms, including lateral flow immunoassays (LFAs), enzyme-linked immunosorbent assays (ELISAs) and high throughput serological assays (HTSAs). To estimate seroprevalence, we utilized the Bayesian statistical method to adjust for sensitivity and specificity of the commercial tests used.

RESULTS

We report than an estimated seropositive rate of RI blood donors of approximately 0.6% existed in April-May of 2020. Daily new case rates peaked in RI in late April 2020. We found HTSAs and LFAs were positively correlated with ELISA assays to detect antibodies specific to SARS-CoV-2 in blood donors.

CONCLUSIONS

These data imply that seroconversion, and thus infection, is likely not widespread within this population. We conclude that IgG LFAs and HTSAs are suitable to conduct seroprevalence assays in random populations. More studies will be needed using validated serological tests to improve the precision and report the kinetic progression of seroprevalence estimates.

Seroprevalence of SARS-CoV-2 Antibodies in Rhode Island From a Statewide Random Sample

Objectives. To characterize statewide seroprevalence and point prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Rhode Island.Methods. We conducted a cross-sectional survey of randomly selected households across Rhode Island in May 2020. Antibody-based and polymerase chain reaction (PCR)-based tests for SARS-CoV-2 were offered. Hispanics/Latinos and African Americans/Blacks were oversampled to ensure adequate representation. Seroprevalence estimations accounted for test sensitivity and specificity and were compared according to age, race/ethnicity, gender, housing environment, and transportation mode.Results. Overall, 1043 individuals from 554 households were tested (1032 antibody tests, 988 PCR tests). The estimated seroprevalence of SARS-CoV-2 antibodies was 2.1% (95% credible interval [CI] = 0.6, 4.1). Seroprevalence was 7.5% (95% CI = 1.3, 17.5) among Hispanics/Latinos, 3.8% (95% CI = 0.0, 15.0) among African Americans/Blacks, and 0.8% (95% CI = 0.0, 2.4) among non-Hispanic Whites. Overall PCR-based prevalence was 1.5% (95% CI = 0.5, 3.1).Conclusions. Rhode Island had low seroprevalence relative to other settings, but seroprevalence was substantially higher among African Americans/Blacks and Hispanics/Latinos. Rhode Island sits along the highly populated northeast corridor, making our findings broadly relevant to this region of the country. Continued monitoring via population-based sampling is needed to quantify these impacts going forward.

Empirical comparison of analytical approaches for identifying molecular HIV-1 clusters

Public health interventions guided by clustering of HIV-1 molecular sequences may be impacted by choices of analytical approaches. We identified commonly-used clustering analytical approaches, applied them to 1886 HIV-1 Rhode Island sequences from 2004-2018, and compared concordance in identifying molecular HIV-1 clusters within and between approaches. We used strict (topological support ≥ 0.95; distance 0.015 substitutions/site) and relaxed (topological support 0.80-0.95; distance 0.030-0.045 substitutions/site) thresholds to reflect different epidemiological scenarios. We found that clustering differed by method and threshold and depended more on distance than topological support thresholds. Clustering concordance analyses demonstrated some differences across analytical approaches, with RAxML having the highest (91%) mean summary percent concordance when strict thresholds were applied, and three (RAxML-, FastTree regular bootstrap- and IQ-Tree regular bootstrap-based) analytical approaches having the highest (86%) mean summary percent concordance when relaxed thresholds were applied. We conclude that different analytical approaches can yield diverse HIV-1 clustering outcomes and may need to be differentially used in diverse public health scenarios. Recognizing the variability and limitations of commonly-used methods in cluster identification is important for guiding clustering-triggered interventions to disrupt new transmissions and end the HIV epidemic.

Limited Secondary Transmission of SARS-CoV-2 in Child Care Programs - Rhode Island, June 1-July 31, 2020

On June 1, 2020, with declines in coronavirus disease 2019 (COVID-19) cases and hospitalizations in Rhode Island,* child care programs in the state reopened after a nearly 3-month closure implemented as part of mitigation efforts. To reopen safely, the Rhode Island Department of Human Services (RIDHS) required licensed center- and home-based child care programs to reduce enrollment, initially to a maximum of 12 persons, including staff members, in stable groups (i.e., staff members and students not switching between groups) in physically separated spaces, increasing to a maximum of 20 persons on June 29. Additional requirements included universal use of masks for adults, daily symptom screening of adults and children, and enhanced cleaning and disinfection according to CDC guidelines.^† As of July 31, 666 of 891 (75%) programs were approved to reopen, with capacity for 18,945 children, representing 74% of the state's January 2020 child care program population (25,749 children).

Post-exposure rabies prophylaxis for mass bat exposures: Case series and systematic review

To assess and describe the use of rabies post-exposure prophylaxis (PEP) related to mass bat exposures (MBEs) in the literature and in the state of Rhode Island. Data on MBE events occurring between 2010 and 2016 from the Rhode Island Department of Health (RIDOH) were reviewed to determine PEP usage. For comparison, a systematic review was also performed by searching PubMed, EMBASE, Cochrane Library and Web of Science using the keywords 'rabies,' 'bat' and 'exposure.' There were three MBE events in Rhode Island between 2010 and 2016 in which groups of individuals were asleep during the potential exposure. As a result, RIDOH provided PEP to those involved in the event. In a systematic review of 12 published reports, a variety of settings were involved in MBEs: camping sites, a domestic flight, a neonatal intensive care unit and dormitories. The number of potential rabies exposures ranged from five to 1,429 people. PEP recommendations for assessed persons ranged from 0% to 100% across events (median 21%). The variation in PEP recommendations following a MBE may be dependent on medical need, past precedent or preference. Federal guidance for MBE is needed to add clarity and to minimize the variability in PEP recommendations for such events in the future.

Overview of Antimicrobial Stewardship Activities in Rhode Island

Due to the rise of antibiotic resistance, and the decrease of novel antibiotics coming to market, the Centers for Disease Control and Prevention (CDC) has formally recognized that action must take place to ensure appropriate antibiotic use, and maintain public health. The RI Department of Health (RIDOH) Director responded by initiating the RI Antimicrobial Stewardship and Environmental Cleaning Task Force (RIAMSEC), a multidisciplinary team that set in motion a set of tasks for RIDOH. As a result, a survey of antibiotic stewardship programs (ASP) at the RI acute care hospitals (ACHs) and long-term care (LTC) facilities revealed gaps in addressing HAI prevention and AMS goals for the state. RIDOH has therefore expanded statewide coordination efforts to form the RI Healthcare-Associated Infection Prevention and Antimicrobial Stewardship Coalition which is intended to effectively prevent HAI and ultimate improve the Centers for Medicare and Medicaid Services Hospital-acquired Condition (HAC) Reduction scores in Rhode Island.[Full article available at http://rimed.org/rimedicaljournal-2018-06.asp].

Meningococcal carriage among a university student population - United States, 2015

OBJECTIVES

Several outbreaks of serogroup B meningococcal disease have occurred among university students in recent years. In the setting of high coverage of the quadrivalent meningococcal conjugate vaccine and prior to widespread use of serogroup B meningococcal vaccines among adolescents, we conducted surveys to characterize the prevalence and molecular characteristics of meningococcal carriage among university students.

METHODS

Two cross-sectional oropharyngeal carriage surveys were conducted among undergraduates at a Rhode Island university. Isolates were characterized using slide agglutination, real-time polymerase chain reaction (rt-PCR), and whole genome sequencing. Adjusted prevalence ratios and 95% confidence intervals were calculated using Poisson regression to determine risk factors for carriage.

RESULTS

A total of 1837 oropharyngeal specimens were obtained from 1478 unique participants. Overall carriage prevalence was 12.7-14.6% during the two survey rounds, with 1.8-2.6% for capsular genotype B, 0.9-1.0% for capsular genotypes C, W, or Y, and 9.9-10.8% for nongroupable strains by rt-PCR. Meningococcal carriage was associated with being male, smoking, party or club attendance, recent antibiotic use (inverse correlation), and recent respiratory infections.

CONCLUSIONS

In this university setting, the majority of meningococcal carriage was due to nongroupable strains, followed by serogroup B. Further evaluation is needed to understand the dynamics of serogroup B carriage and disease among university students.

Rhode Island Lyme Disease Surveillance Summary 2014-2016

[Full article available at http://rimed.org/rimedicaljournal-2017-11.asp].

Meningococcal Carriage Evaluation in Response to a Serogroup B Meningococcal Disease Outbreak and Mass Vaccination Campaign at a College-Rhode Island, 2015-2016

Background

Serogroup B meningococcal disease caused 7 US university outbreaks during 2013-2016. Neisseria meningitidis can be transmitted via asymptomatic nasopharyngeal carriage. MenB-FHbp (factor H binding protein), a serogroup B meningococcal (MenB) vaccine, was used to control a college outbreak. We investigated MenB-FHbp impact on meningococcal carriage.

Methods

Four cross-sectional surveys were conducted in conjunction with MenB-FHbp vaccination campaigns. Questionnaires and oropharyngeal swabs were collected from students. Specimens were evaluated using culture, slide agglutination, real-time polymerase chain reaction (rt-PCR), and whole genome sequencing. Adjusted prevalence ratios (aPRs) were calculated using generalized estimating equations.

Results

During each survey, 20%-24% of participants carried any meningococcal bacteria and 4% carried serogroup B by rt-PCR. The outbreak strain (ST-9069) was not detected during the initial survey; 1 student carried ST-9069 in the second and third surveys. No carriage reduction was observed over time or with more MenB-FHbp doses. In total, 615 students participated in multiple surveys: 71% remained noncarriers, 8% cleared carriage, 15% remained carriers, and 7% acquired carriage. Ten students acquired serogroup B carriage: 3 after 1 MenB-FHbp dose, 4 after 2 doses, and 3 after 3 doses. Smoking (aPR, 1.3; 95% confidence interval [CI], 1.1-1.5) and male sex (aPR, 1.3; 95% CI, 1.1-1.5) were associated with increased meningococcal carriage.

Conclusions

Carriage prevalence on campus remained stable, suggesting MenB-FHbp does not rapidly reduce meningococcal carriage or prevent serogroup B carriage acquisition. This reinforces the need for high vaccination coverage to protect vaccinated individuals and chemoprophylaxis for close contacts during outbreaks.

Preventing Foodborne and Enteric Illnesses Among At-Risk Populations in the United States and Rhode Island

One out of every six people in the United States is estimated to become sick each year from pathogens that can cause foodborne illness. The groups at greatest risk for serious illness, hospitalization, or death include young children, older adults, people with chronic conditions, and pregnant women. Such health disparities must be considered along with those disparities that may exist among racial and ethnic groups and among groups of varying socioeconomic status. We analyzed risk profiles for enteric disease using data from Rhode Island and the nation as a whole, exploring disparities among groups defined by demographic and health characteristics. As expected, disparities in the burden of enteric illnesses are not limited to racial or ethnic differences in disease burden, or in differences otherwise attributable to socioeconomic status. Age is an especially important determinant of risk, as is residential status. Other groups found to be especially vulnerable to foodborne and enteric illnesses in Rhode Island include pregnant women and those with certain health conditions (e.g., cancer, liver disease or immunosuppression). By understanding what groups are at increased risk, providers can more effectively counsel their patients to mitigate risk and effectively treat these conditions. [Full article available at http://rimed.org/rimedicaljournal-2016-11.asp].

Health Equity, Social Justice, and HIV in Rhode Island: A Contemporary Challenge

From its beginning, HIV has primarily affected marginalized populations, such as injection drug users, gay, bisexual and other men who have sex with men (GBMSM), and minority racial and ethnic groups. HIV is a disease that, from the start, has been strongly influenced by issues related to social justice and health equity due to its intersection with behaviors among at-risk populations. While some of the risks associated with HIV have been successfully mitigated through social justice initiatives related to needle exchange programs and routine HIV testing of pregnant women, Rhode Island remains confronted with the health equity challenges of preventing HIV transmission and ensuring access to HIV care/treatment, especially for Black/African Americans, Hispanics, and GBMSM. [Full article available at http://rimed.org/rimedicaljournal-2016-11.asp].

Prevention and control of hepatitis C in rhode island

Concern about the morbidity and mortality of hepatitis C infection is increasing. Persons born from 1945 to 1965 are most significantly affected, with the majority unaware of their infection, and will otherwise go untreated. Up to three-fourths of hepatitis C-related deaths occur in this population of "baby boomers." Since 2007, mortality from hepatitis C has exceeded that from HIV, nationally and in Rhode Island. New treatment options for hepatitis C emphasize the potential for cure of hepatitis C that is distinct from HIV. Financial resources and integration of hepatitis C partners and services in Rhode Island will be instrumental in reducing hepatitis C infections and increasing the number of cases cured. We describe public health investments in the past, present, and future to implement strategies for effectively addressing hepatitis C in the state.

Addressing the increasing burden of sexually transmitted infections in Rhode Island

The rates of sexually transmitted infections (STI) including chlamydia, gonorrhea, and syphilis, are increasing across the United States, including in Rhode Island (RI). These STIs affect many otherwise healthy adolescents and young adults, and represent a significant source of morbidity. The Centers for Disease Control and Prevention encourages states to develop strategies for addressing increasing STI rates in the setting of diminishing public health resources. The RI Department of Health (DOH) works with providers and funded community- based organizations to promote STI screening, expedited partner therapy, and partner services to reduce STI rates. The Miriam Hospital Immunology Center opened a public HIV/STI Clinic, which offers free and confidential testing for HIV, viral hepatitis, chlamydia, gonorrhea, and syphilis, as well as post-exposure prophylaxis (PEP) and pre-exposure prophylaxis (PrEP) services to prevent HIV. In collaboration with the RI DOH, the Clinic serves as a referral source across the state for complicated STI cases.

Streptococcus pneumoniae serotype 15A in psychiatric unit, Rhode Island, USA, 2010-2011

During a pneumococcal disease outbreak in a pediatric psychiatric unit in a hospital in Rhode Island, USA, 6 (30%) of 20 patients and staff were colonized with Streptococcus pneumoniae serotype 15A, which is not included in pneumococcal vaccines. The outbreak subsided after implementation of antimicrobial drug prophylaxis and enhanced infection control measures.

Emerging global epidemiology of measles and public health response to confirmed case in Rhode Island

Measles is a highly contagious viral disease and rapid identification and control of cases/outbreaks are important global health priorities. Measles was declared eliminated from the United States in March 2000. However, importations from endemic countries continued through out the last decade and in 2011, the United States reported its highest number of cases in 15 years. With a global snapshot of current measles epidemiology and the persistent risk of transnational spread based on population movement as the backdrop, this article describes the rare event of a measles case identification in the state of Rhode Island and the corresponding public health response. As the global effort for measles elimination continues to make significant progress, sensitive public health surveillance systems and strong routine immunization programs will be important to ensure we maintain local and regional control.

Epidemiology of 2009 pandemic influenza A (H1N1) deaths in the United States, April-July 2009

During the spring of 2009, pandemic influenza A (H1N1) virus (pH1N1) was recognized and rapidly spread worldwide. To describe the geographic distribution and patient characteristics of pH1N1-associated deaths in the United States, the Centers for Disease Control and Prevention requested information from health departments on all laboratory-confirmed pH1N1 deaths reported from 17 April through 23 July 2009. Data were collected using medical charts, medical examiner reports, and death certificates. A total of 377 pH1N1-associated deaths were identified, for a mortality rate of .12 deaths per 100,000 population. Activity was geographically localized, with the highest mortality rates in Hawaii, New York, and Utah. Seventy-six percent of deaths occurred in persons aged 18-65 years, and 9% occurred in persons aged ≥ 65 years. Underlying medical conditions were reported for 78% of deaths: chronic lung disease among adults (39%) and neurologic disease among children (54%). Overall mortality associated with pH1N1 was low; however, the majority of deaths occurred in persons aged <65 years with underlying medical conditions.

Pet rodents and fatal lymphocytic choriomeningitis in transplant patients

A unique strain of this virus was traced back to hamsters from an Ohio rodent distribution facility.

In April 2005, 4 transplant recipients became ill after receiving organs infected with lymphocytic choriomeningitis virus (LCMV); 3 subsequently died. All organs came from a donor who had been exposed to a hamster infected with LCMV. The hamster was traced back through a Rhode Island pet store to a distribution center in Ohio, and more LCMV-infected hamsters were discovered in both. Rodents from the Ohio facility and its parent facility in Arkansas were tested for the same LCMV strain as the 1 involved in the transplant-associated deaths. Phylogenetic analysis of virus sequences linked the rodents from the Ohio facility to the Rhode Island pet store, the index hamster, and the transplant recipients. This report details the animal traceback and the supporting laboratory investigations.

Transmission of lymphocytic choriomeningitis virus by organ transplantation

BACKGROUND

In December 2003 and April 2005, signs and symptoms suggestive of infection developed in two groups of recipients of solid-organ transplants. Each cluster was investigated because diagnostic evaluations were unrevealing, and in each a common donor was recognized.

METHODS

We examined clinical specimens from the two donors and eight recipients, using viral culture, electron microscopy, serologic testing, molecular analysis, and histopathological examination with immunohistochemical staining to identify a cause. Epidemiologic investigations, including interviews, environmental assessments, and medical-record reviews, were performed to characterize clinical courses and to determine the cause of the illnesses.

RESULTS

Laboratory testing revealed lymphocytic choriomeningitis virus (LCMV) in all the recipients, with a single, unique strain of LCMV identified in each cluster. In both investigations, LCMV could not be detected in the organ donor. In the 2005 cluster, the donor had had contact in her home with a pet hamster infected with an LCMV strain identical to that detected in the organ recipients; no source of LCMV infection was found in the 2003 cluster. The transplant recipients had abdominal pain, altered mental status, thrombocytopenia, elevated aminotransferase levels, coagulopathy, graft dysfunction, and either fever or leukocytosis within three weeks after transplantation. Diarrhea, peri-incisional rash, renal failure, and seizures were variably present. Seven of the eight recipients died, 9 to 76 days after transplantation. One recipient, who received ribavirin and reduced levels of immunosuppressive therapy, survived.

CONCLUSIONS

We document two clusters of LCMV infection transmitted through organ transplantation.

Control of West Nile virus, Rhode Island, 2003

Thanks largely to systematic larviciding by the State's 39 municipalities, and aided by the public's destruction of "backyard" mosquito habitats and adoption of personal protective measures (clothing, repellant), Rhode Island minimized the potential human burden of WNV during the 2003 mosquito season (six serious WNV cases, one death, and no reports of WNV-tainted blood donations). The potential burden of WNV on domestic animals was also reduced through immunization. Nonetheless, the State's first WNV death reminds us of the danger this disease poses for the very young, for elders, and for people of all ages who are immune-compromised. Similarly, the widespread location of birds positive for WNV signifies the ubiquity of risk. All mosquitoes must be avoided. Based on its experience with WNV control over the past few years, the State will continue and enhance its surveillance and control efforts in 2004. Once again, systematic larviciding by municipalities and continuing public education through multiple channels will form the backbone of control, supported by active surveillance for the virus in the wild, in domestic animals, and in humans. For the latter effort, the vigilance of the health care community is of signal importance to the protection of the public. Every human case is investigated thoroughly, to establish as accurately as possible the time and place of exposure. DEM and HEALTH use this information to assess potential weaknesses in WNV control efforts, and to take corrective action, as necessary. Health care providers also play an essential role in public education, reminding patients (all patients, but especially the very young, elders, and the immune-compromised) to avoid mosquito bites. Discussing the avoidance of mosquito bites with patients who engage in regular outdoor activity is especially important. School physicians and the medical directors of nursing homes are well-positioned to keep mosquito control and avoidance on the agenda of their respective institutions. Together, we can control the burden of this disease among domestic animals and humans, if we continue to pursue mosquito control and personal protection aggressively. If we don't, the potential for tragedy is tremendous, as evidenced by the recent experience of other regions of the country.

A Public Health Response to Bioterrorism with Bacillus Anthracis

In October 2001, public health departments across the United States were part of an intensive response to a bioterrorism event using anthrax spores delivered by mail. It is useful to examine this experience as an unscripted exercise of bioterrorism response capacity, more realistic than scenarios of planned exercises. The event particularly challenged public health laboratory and communications capacity, but it also tested surveillance and training capacity. The bioterrorism response demonstrated the importance of strong partnerships between the public health laboratory and emergency response agencies as well as medical providers and the usefulness of open, flexible communication strategies.

Risk factors for syphilis among incarcerated women in Rhode Island

Syphilis remains a significant problem in the United States. The prison environment is an ideal location to identify and treat syphilis. We undertook this study to describe the correlates and risk factors for syphilis among incarcerated women in Rhode Island. The study design was a review of all cases of syphilis identified through routine screening in the state prison and a case control study. Between 1992 and 1998, among 6,249 incarcerated women, 86 were found to have syphilis; of these, 29 were primary and secondary cases representing 49% of infectious cases of syphilis in women in the state. The prison environment offers a unique opportunity for the diagnosis and treatment of syphilis.