Don Weiss

Monitoring the Impact of Influenza by Age: Emergency Department Fever and Respiratory Complaint Surveillance in New York City

Background The importance of understanding age when estimating the impact of influenza on hospitalizations and deaths has been well described, yet existing surveillance systems have not made adequate use of age-specific data. Monitoring influenza-related morbidity using electronic health data may provide timely and detailed insight into the age-specific course, impact and epidemiology of seasonal drift and reassortment epidemic viruses. The purpose of this study was to evaluate the use of emergency department (ED) chief complaint data for measuring influenza-attributable morbidity by age and by predominant circulating virus. Methods and Findings We analyzed electronically reported ED fever and respiratory chief complaint and viral surveillance data in New York City (NYC) during the 2001–2002 through 2005–2006 influenza seasons, and inferred dominant circulating viruses from national surveillance reports. We estimated influenza-attributable impact as observed visits in excess of a model-predicted baseline during influenza periods, and epidemic timing by threshold and cross correlation. We found excess fever and respiratory ED visits occurred predominantly among school-aged children (8.5 excess ED visits per 1,000 children aged 5–17 y) with little or no impact on adults during the early-2002 B/Victoria-lineage epidemic; increased fever and respiratory ED visits among children younger than 5 y during respiratory syncytial virus-predominant periods preceding epidemic influenza; and excess ED visits across all ages during the 2003–2004 (9.2 excess visits per 1,000 population) and 2004–2005 (5.2 excess visits per 1,000 population) A/H3N2 Fujian-lineage epidemics, with the relative impact shifted within and between seasons from younger to older ages. During each influenza epidemic period in the study, ED visits were increased among school-aged children, and each epidemic peaked among school-aged children before other impacted age groups. Conclusions Influenza-related morbidity in NYC was highly age- and strain-specific. The impact of reemerging B/Victoria-lineage influenza was focused primarily on school-aged children born since the virus was last widespread in the US, while epidemic A/Fujian-lineage influenza affected all age groups, consistent with a novel antigenic variant. The correspondence between predominant circulating viruses and excess ED visits, hospitalizations, and deaths shows that excess fever and respiratory ED visits provide a reliable surrogate measure of incident influenza-attributable morbidity. The highly age-specific impact of influenza by subtype and strain suggests that greater age detail be incorporated into ongoing surveillance. Influenza morbidity surveillance using electronic data currently available in many jurisdictions can provide timely and representative information about the age-specific epidemiology of circulating influenza viruses.

Evaluation of school absenteeism data for early outbreak detection, New York City

BackgroundSchool absenteeism data may have utility as an early indicator of disease outbreaks, however their value should be critically examined. This paper describes an evaluation of the utility of school absenteeism data for early outbreak detection in New York City (NYC).MethodsTo assess citywide temporal trends in absenteeism, we downloaded three years (2001–02, 2002–03, 2003–04) of daily school attendance data from the NYC Department of Education (DOE) website. We applied the CuSum method to identify aberrations in the adjusted daily percent absent. A spatial scan statistic was used to assess geographic clustering in absenteeism for the 2001–02 academic year.ResultsModerate increases in absenteeism were observed among children during peak influenza season. Spatial analysis detected 790 significant clusters of absenteeism among elementary school children (p < 0.01), two of which occurred during a previously reported outbreak.ConclusionMonitoring school absenteeism may be moderately useful for detecting large citywide epidemics, however, school-level data were noisy and we were unable to demonstrate any practical value in using cluster analysis to detect localized outbreaks. Based on these results, we will not implement prospective monitoring of school absenteeism data, but are evaluating the utility of more specific school-based data for outbreak detection.

Diarrheal Illness Detected Through Syndromic Surveillance After a Massive Power Outage: New York City, August 2003

OBJECTIVES We investigated increases in diarrheal illness detected through syndromic surveillance after a power outage in New York City on August 14, 2003. METHODS The New York City Department of Health and Mental Hygiene uses emergency department, pharmacy, and absentee data to conduct syndromic surveillance for diarrhea. We conducted a case-control investigation among patients presenting during August 16 to 18, 2003, to emergency departments that participated in syndromic surveillance. We compared risk factors for diarrheal illness ascertained through structured telephone interviews for case patients presenting with diarrheal symptoms and control patients selected from a stratified random sample of nondiarrheal patients. RESULTS Increases in diarrhea were detected in all data streams. Of 758 patients selected for the investigation, 301 (40%) received the full interview. Among patients 13 years and older, consumption of meat (odds ratio [OR]=2.7, 95% confidence interval [CI]=1.2, 6.1) and seafood (OR=4.8; 95% CI=1.6, 14) between the power outage and symptom onset was associated with diarrheal illness. CONCLUSIONS Diarrhea may have resulted from consumption of meat or seafood that spoiled after the power outage. Syndromic surveillance enabled prompt detection and systematic investigation of citywide illness that would otherwise have gone undetected.

Transfusion-associated babesiosis after heart transplant.

We describe a 54-year-old spleen-intact man with transfusion-associated Babesia microti infection after a heart transplant. Adult respiratory distress syndrome developed in the patient, and he required mechanical ventilation. Our experiences with this patient suggest that babesiosis should be considered in the differential diagnosis of transplant patients who have fever and hemolytic anemia.

Elevated Risk for Invasive Meningococcal Disease Among Persons With HIV

Context Invasive meningococcal disease (IMD) is life-threatening. Current recommendations for receipt of meningococcal vaccine to prevent IMD do not include HIV-infected adults. Contribution HIV infection and IMD are reportable diseases in New York City. Investigators linked databases and found that, compared with the general population, people living with HIV/AIDS (PLWHA) had a relative risk for IMD of 10. Risk was greatest in persons with CD4+ counts less than 0.200109 cells/L. Serotypes in nearly 90% of IMD cases in adult PLWHA are included in current meningococcal vaccines. Implication Studies of vaccine effectiveness are needed in adult PLWHA, who may be appropriate candidates for routine immunization with meningococcal vaccine. The Editors Infection with HIV is associated with an increased risk for several bacterial infections, most notably Mycobacterium tuberculosis, Streptococcus pneumonia, nontyphoid Salmonella, Haemophilus influenzae, and Staphylococcus aureus(1, 2). Data on the relationship between HIV and Neisseria meningitidis are limited. An analysis of surveillance data from 1988 to 1993 from the 8-county metropolitan area of Atlanta, Georgia, found that HIV-infected adults aged 25 to 49 years had a nearly 24-fold increased risk for invasive meningococcal disease (IMD) (3). More recently, Cohen and colleagues reported that the incidence of IMD in HIV-infected individuals of all ages in South Africa was 11 times greater than that among HIV-uninfected individuals (4). Moreover, the Centers for Disease Control and Prevention (CDC) recently published data from its Active Bacterial Core surveillance sites indicating that the cumulative annual incidence of IMD in individuals who meet the case definition for AIDS is approximately 13 times greater than in those who do not (5). In 2005, a new tetravalent meningococcal polysaccharideprotein conjugate vaccine (MCV4) was approved and recommended for routine use in young adolescents (aged 11 to 12 years) on the basis of an increased risk for IMD in college students living in dormitories and a cost-effectiveness analysis (6). Current MCV4 recommendations, however, do not include people living with HIV/AIDS (PLWHA), other than HIV-infected adolescents (5). The absence of meningococcal vaccine recommendations in HIV-infected adults is due, in part, to insufficient data on vaccine efficacy in HIV-infected adults, the duration of immunity, and the concern over the cost-effectiveness of such recommendations. To explore the relationship between HIV and IMD in New York City (NYC), we matched population-based IMD surveillance data with HIV and vital statistics registries to calculate rates of IMD and IMD-related death from 2000 to 2011 among PLWHA and persons not known to be HIV-infected. We also analyzed the serogroup distribution among IMD cases and evaluated the effect of immune status and viral load (VL) on risk for IMD among PLWHA.An outbreak of serogroup C IMD was recognized in NYC among men who have sex with men (MSM) in the fall of 2012 after the data analysis for this article was completed (7). A total of 17 cases and 6 deaths were identified in 2012 and 2013, with 10 of the cases having occurred in PLWHA. These 17 cases were not included in the analysis. Methods Study Population Both IMD and HIV are reportable diseases in NYC. We included IMD cases in NYC that were diagnosed during 2000 to 2011, met the Council of State and Territorial Epidemiologists case definitions for confirmed or probable meningococcal disease (8), and were reported to the NYC Department of Health and Mental Hygiene (DOHMH). The IMD diagnosis date was defined as the date of the clinical specimen or findings that met the case definition. Cases of IMD from 2000 to 2011 were matched to the DOHMHs Office of Vital Statistics death registry to determine vital status and underlying cause of death. Death due to IMD was defined as death occurring within 30 days of diagnosis with a final cause consistent with meningococcal disease. When IMD was not specifically listed as the cause of death, the record was reviewed by 2 independent medical reviewers who both needed to concur that the death was due to IMD. The state of New York mandated confidential, name-based reporting of HIV-related events in 1998, with implementation in June 2000. The law requires reporting of all diagnoses of HIV and AIDS, all HIV-related illness, all positive Western blot test results for HIV antibody, all VL and CD4+ cell count values, and all HIV genotypes (914). The NYC HIV Surveillance Registry (HSR) is a population-based registry of all AIDS cases diagnosed in NYC since 1981 and all HIV cases diagnosed since 2000. The HSR is regularly matched to local and national vital statistics death registries to update vital status for PLWHA and is continuously updated with HIV-related laboratory reports. Since 2005, all CD4+ cell count and HIV VL results have been electronically reported to the HSR. Incoming laboratory reports from providers and laboratories that cannot be matched to an existing person in the registry initiate a field investigation to confirm through medical record review that the case meets surveillance definitions for HIV, AIDS, or both (15) and to record data elements to be used to establish a date of diagnosis and collect other data required for surveillance. We matched case patients with IMD to the HSR by using a deterministic automated algorithm comprising 36 keys based on combinations of first name; last name; date of birth; Social Security number; and the soundex function in SAS, version 9.2 (SAS Institute, Cary, North Carolina), which adjusts for names spelled phonetically. The algorithm was ordered hierarchically such that lower keys were considered to represent matches more likely to be true. Exact matches on keys 1 to 7 were accepted as true matches without further review. Matches on keys 8 to 36 prompted a manual review by 2 independent reviewers with access to additional information about potentially matching pairs of case patients, such as residential address (16). To account for the W-shaped age distribution of IMD (17) and control for the confounding effect of age on the relative risk (RR) for IMD in PLWHA, we excluded case patients younger than 15 years and older than 64 years from the study population. The primary IMD syndrome was determined by clinical and laboratory findings per the following hierarchy if multiple syndromes existed: meningococcemia > meningitis > bacteremia > other (for example, joint or pneumonia). The IMD serogroup was determined by slide agglutination at the NYC Public Health Laboratory or by polymerase chain reaction at the Wadsworth Center State Public Health Laboratory. Statistical Analysis The number of PLWHA was estimated as the product of age-specific HIV prevalence rates (calculated from HSR data as persons diagnosed with HIV in NYC and reported to DOHMH by 30 September 2012) and intercensal population estimates for persons aged 15 to 64 years and was then averaged for 2000 to 2011. Populations for 3-year intervals were similarly estimated. The population of HIV-uninfected persons aged 15 to 64 years was calculated as the difference between the average total NYC populations and the interval-specific PLWHA population estimates. Descriptive statistics and the chi-square test were used to compare case patients with IMD on categorical variables by HIV status and also to test for trend in the proportion of patients with IMD who were HIV-infected over time. Means and SDs were used to compare continuous variables by HIV status. The average annual incidence rate of IMD per 100000 persons was computed for the 12-year period (20002011) and by 3-year intervals (20002002, 20032005, 20062008, and 20092011) among both PLWHA and HIV-uninfected persons. The RRs for IMD among PLWHA and 95% CIs were calculated for the 12- and 3-year intervals. The RR for IMD was also stratified by 3 age categories (15 to 24, 25 to 44, and 45 to 64 years) and by sex over the entire interval. Cigarette smoking frequently appears in the literature as a risk factor for IMD (1821). Questions on smoking were added to IMD case investigations in 2006, and data were available for three quarters of IMD cases during this period (cases with missing data were excluded). We used population-based estimates of smoking prevalence from the NYC Community Health Survey for 2006 and 2007 (39.6% among respondents self-reporting HIV infection and 18.8% among those self-reporting no HIV/AIDS) (22) to estimate the smoking prevalence among individuals without IMD in order to stratify the RR for IMD in PLWHA by smoking status. A sensitivity analysis of HIV ascertainment was also conducted using data from a serosurvey of undiagnosed HIV infection. The RR was recalculated by adding 14% to the PLWHA population with no additional cases of IMD (23). To compare the IMD case-fatality ratio (CFR) among patients with IMD and HIV and those with IMD only, we divided the CFR among the former for 2000 to 2011 by the CFR among the latter. A multivariate logistic regression model was used to obtain an age-adjusted odds ratio (OR) of death in case patients with IMD and HIV. The proportion of IMD cases potentially preventable by MCV4 vaccination (serogroups A, C, Y, and W) was compared by HIV status. To explore whether immune suppression and lack of HIV viral suppression were associated with higher IMD risk in PLWHA, we performed separate casecontrol analyses of the odds of IMD by CD4+ cell count and HIV VL among a subset of case patients with IMD and HIV. People living with HIV/AIDS with CD4+ cell counts and VL from the HSR in 2005 or later and test dates within 91 days of the IMD diagnosis date were eligible for selection (before 2005, only low CD4+ cell counts and detectable VL were reportable). All persons without IMD in the HSR who had CD4+ cell counts and VL were eligible to serve as control patients. For the 2 analyses, case patients w

Methicillin-susceptible Staphylococcus aureus ST398, New York and New Jersey, USA.

To the Editor: Clinical infections with livestock-associated Staphylococcus aureus sequence type (ST) 398 have been reported in Europe, Canada, and the People’s Republic of China (1), as well as the Caribbean (2,3), and Colombia (4). Most reports describe infection with methicillin-resistant S. aureus; relatively few describe infection with methicillin-susceptible S. aureus (MSSA). In the United States, colonization of healthy adults by ST398 has been reported in Iowa (5) and in New York, New York (2); MSSA infections have been anecdotally reported in St. Louis, Missouri (6), and The Bronx, New York (7). We describe 8 infections with MSSA ST398 in the New York City area during a 7-year period (2004–2010). Five infections with a related ST (ST291) from clonal complex (CC) 398 also were identified. These findings highlight the emergence of clinical infections with 2 distinct CC398 sequence types in the New York City area. Retrospective typing of 4,167 clinical S. aureus isolates from various studies involving inpatients and outpatients in the New York City area identified 13 mecA-negative isolates with CC398-associated spa types (Table). Nine isolates were obtained from cultures of outpatients with skin and soft tissue infections; samples were submitted by physicians in the community. One isolate was associated with recurring skin and soft tissue infections in multiple body sites (BK21466); another was associated with genital infection (BK21732). Of the 4 ST398 isolates derived from bloodstream infections in hospitalized patients, 3 were recovered from intravenous drug users, 1 of whom died 1 day after admission for variceal bleeding (BK26722). Unlike the multidrug-resistant ST398 MSSA recently described in Colombia (4), most isolates in this study were susceptible to all antimicrobial drugs tested except penicillin, although several strains exhibited resistance to clindamycin and erythromycin. One isolate (BK23527) was submitted as oxacillin resistant (MIC ≥4 μg/mL) but lacked the mecA gene, which suggested that another mechanism was contributing to the resistance phenotype. Table Characteristics of Staphylococcus aureus clonal complex 398 isolates, New York and New Jersey, USA, 2004–2010* Multilocus sequence typing confirmed 8 isolates as ST398 (3–35–19–2–20–26–39); 5 isolates were assigned to ST291 (3–37–19–2–20–26–32), a double-locus variant of ST398 (Figure A1, panel A). Most of the ST398 strains were spa type 109 (t571), described in MSSA carriage isolates from New York City (2) and MSSA infections from China (1), France (8), Martinique (3), the Dominican Republic (2,3), and Colombia (4). BURP (based upon repeat pattern) analysis clustered all of the spa types into spa-CC t571 (Figure A1, panel B); ST398 isolates clustered with spa type 109 (t571), whereas ST291 isolates clustered with spa type 865 (t2313). Pulsed-field gel electrophoresis was also performed on the 11 available isolates. Although the ST291 isolates were sensitive to digestion with SmaI, pulsed-field gel electrophoresis was performed with Cfr9I to compare all isolates simultaneously. As expected, the ST398 and ST291 isolates clustered separately (data not shown); 4 distinct patterns were observed within each cluster (Table). Only the ST398 isolates were positive for a CC398 lineage-specific PCR that targets the unique restriction-modification system sau1-hsdS1 (9), further highlighting the differences between ST291 and ST398. None of the isolates harbored the genes coding for Panton-Valentine leukocidin. Because of the retrospective nature of the findings, epidemiologic information for each isolate was limited. One patient (BK19382) reported travel to the Dominican Republic; Caribbean nationality was reported for BK27037 (Puerto Rico) and BK31274 (Trinidad). The cases described here occurred in urban and suburban settings, reflecting the likelihood that exposure to livestock was relatively low; however, travel history was unknown for most of the patients. Previous reports have linked ST398 transmission to other reservoirs, including companion animals, live animal food markets, and commercial meat products (1,2). However, data from a recent genome sequencing study suggest that MSSA ST398 is human in origin (10); other evidence suggests that certain lineages, particularly spa type 109 (t571), might circulate at low levels in humans in the absence of livestock exposure (8). Our findings seem to support the hypothesis of low-level ST398 MSSA prevalence, and further surveillance might uncover additional cases of colonization or infection with ST398- and ST291-related strains in the New York City area. For example, active surveillance cultures performed at one of the 3 hospitals during January–March 2009 detected 7 additional ST398 and 3 additional ST291 isolates among 260 MSSA carriage strains (data not shown). In addition to the intrinsic virulence exhibited by ST398 MSSA in previous studies, the potential to acquire resistance to multiple classes of antimicrobial drugs (1,4,10), as well as virulence factors such as Panton-Valentine leukocidin (8), warrants continued surveillance in light of recent ST398 methicillin-resistant S. aureus outbreaks in health care settings (1).

Enhanced drop-in syndromic surveillance in New York City following September 11, 2001.

After the 2001 World Trade Center disaster, the New York City Department of Health was under heightened alert for bioterrorist attacks in the city. An emergency department (ED) syndromic surveillance system was implemented with the assistance of the Centers for Disease Control and Prevention to ensure early recognition of an increase or clustering of disease syndromes that might represent a disease outbreak, whether natural or intentional. The surveillance system was based on data collected 7 days a week at area EDs. Data collected were translated into syndromes, entered into an electronic database, and analyzed for aberrations in space and time within 24 hours. From September 14–27, personnel were stationed at 15 EDs on a 24-hour basis (first staffing period); from September 29–October 12, due to resource limitations, personnel were stationed at 12 EDs on an 18-hour basis (second staffing period). A standardized form was used to obtain demographic information and classify each patient visit into 12 syndrome categories. Seven of these represented early manifestations of bioterrorist agents. Data transfer and analysis for time and space clustering (alarms) by syndrome and age occurred daily. Retrospective analyses examined syndrome trends, differences in reporting between staffing periods, and the staff’s experience during the project. A total of 67,536 reports were received. The system captured 83.9% of patient visits during the first staffing period, and 60.8% during the second staffing period (P<01). Five syndromes each accounted for more than 1% of visits: trauma, asthma, gastrointestinal illness, upper/lower respiratory infection with fever, and anxiety. Citywide temporal alarms occurred eight times for three of the major bioterrorism-related syndromes. Spatial clustering alarms occurred 16 time by hospital location and 9 times by ZIP code for the same three syndromes. No outbreaks were detected. On-site staffing to facilitate data collection and entry, supported by daily analysis of ED visits, is a feasible short-term approach to syndromic surveillance during high-profile events. The resources required to operate such a system, however, cannot be sustained for the long term. This system was changed to an electronic-based ED syndromic system using triage log data that remains in operation.

Epidemiologic Investigation and Targeted Vaccination Initiative in Response to an Outbreak of Meningococcal Disease among Illicit Drug Users in Brooklyn, New York

BACKGROUND An outbreak of serogroup C meningococcal disease that involved illicit drug users and their contacts occurred in Brooklyn, New York, during 2005 and 2006. METHODS The objectives of this study were to identify the population at risk for meningococcal disease, describe efforts to interrupt disease transmission, and assess the impact of a vaccine initiative. Descriptive and molecular epidemiological analysis was used to define the extent of the outbreak and the common risk factors among outbreak-related cases. A vaccine initiative that used community-based service providers was targeted to illicit drug users and their close contacts. The vaccine initiative was assessed through cessation of outbreak-related cases and the reduction in carriage rate. RESULTS The investigation identified 23 outbreak-related cases of serogroup C meningococcal disease; 17 isolates were indistinguishable and 4 isolates were closely related according to pulsed-field gel electrophoresis. Two additional culture-negative cases had epidemiological links to laboratory-confirmed cases. The median age of patients with outbreak-related cases was 41 years, and 19 (83%) of 23 patients reported an association with illicit drug use. There were 7 outbreak-related deaths. Vaccination was administered to 2763 persons at 29 community locations, including methadone treatment centers, syringe-exchange programs, and soup kitchens. Three additional cases of meningococcal disease due to strains with the same pulsed-field gel electrophoresis pattern were identified after the vaccination initiative. CONCLUSIONS Community-based outbreaks of meningococcal disease are difficult to control, and the decision to vaccinate is not straightforward. Current national guidelines for implementing a vaccination campaign are not strict criteria and cannot be expected to accommodate the myriad of factors that occur in community-based invasive meningococcal disease outbreaks, such as the inability to enumerate the population at risk.

Community-Based Outbreak of Neisseria meningitidis Serogroup C Infection in Men who Have Sex with Men, New York City, New York, USA, 2010-2013.

Questions about how to protect this at-risk population deserve careful consideration.

Invasive Meningococcal Disease in Men Who Have Sex With Men

Since August 2010, 22 cases of invasive meningococcal disease (IMD) among men who have sex with men (MSM) have been reported to the New York City Department of Health and Mental Hygiene (NYC DOHMH) (1). Seven of these men died. The mean age was 34 years, 50% were African American, and 55% were infected with HIV. Among the 12 patients with HIV infection, the median CD4 count was 525 × 109 cells/L and 70% of patients had a viral load level less than 200 copies per milliliter within 90 days of IMD diagnosis. In 2012, meningococcal incidence among NYC MSM was 50-fold greater than the age-adjusted rate for the general population. All isolates were serogroup C, and most were indistinguishable by pulsed-field gel electrophoresis. The current outbreak strain is also related to a serogroup C outbreak that occurred in 2006 among Brooklyn drug users and their close contacts. In response, the NYC DOHMH is recommending meningococcal vaccination for all NYC MSM who are HIV-positive or HIV-negative and have engaged in “intimate contact with a man met through an online Web site, digital application or at a bar or party” (1). In Los Angeles, 4 cases of IMD among MSM have been reported since December 2012. Over the past decade, IMD declined to an all-time low in the United States (0.3 to 0.6 cases per 100 000 persons). Outbreaks account for only 2% of the total meningococcal disease burden (2, 3). Approximately 10% of the general population has nasopharyngeal colonization with meningococcus but rates vary with age, peaking in adolescents and young adults when colonization can be as high as 37% (4). Transmission occurs through prolonged direct contact with upper respiratory secretions from colonized or infected individuals. Risk factors for acquiring Neisseria meningitidis include smoking, close living quarters, bar patronage, and kissing (5). In a small percentage of exposed individuals, Neisseria meningitidis invades the nasopharyngeal mucous membrane and, within days, leads to bloodstream or central nervous system infection. Early clinical signs of IMD are nonspecific but may include an influenza-like illness with severe myalgias, signs of sepsis, and a petechial rash. Herrick’s famous adage from 1919 that “no other infection so quickly slays” remains true today. Death within 24 hours of onset of symptoms is common, and the case-fatality ratio for IMD in the United States is 10% to 15% and is 3-fold greater in outbreaks (3). Considering the current NYC outbreak, important questions about meningococcal transmission and disease control remain unanswered. Why does this infection affect the MSM population? Past epidemiologic studies in MSM found high carriage of oropharyngeal N. meningitidis (43%) and 2% rectal and 1% urethral colonization rates (6). Previous IMD outbreaks among MSM occurred in Toronto in 2001 and in Chicago in 2003 for a combined total of 12 cases, with a case-fatality rate of 42% (7). Subsequent molecular typing of these 2 outbreak strains revealed that they were distinct but had a common multilocus sequence type (ST-11) associated with virulence. Future case–control and molecular epidemiologic investigations will be critical to understanding the specific risk behaviors and the host–pathogen factors promoting transmission inside, but apparently not outside, the MSM community. Is HIV an independent risk factor for meningococcal disease? Increased susceptibility to Pneumococcus, another encapsulated bacterium is a well-described complication of HIV. Studies of sporadic meningococcal disease from the United States and South Africa found a 10- to 20-fold increased risk for IMD associated with HIV infection compared with the age-adjusted population IMD incidence, but other African studies during meningococcal epidemics did not find an association (8, 9). One potential concern in this population is vaccine immunogenicity. Although not studied in HIV-positive adults, quadrivalent meningococcal conjugate vaccine in HIV-positive adolescents with a CD4 percentage greater than 15 is immunogenic (10). Two doses significantly improved response durability in this study population. Given a biologically plausible mechanism to account for increased risk and the continued occurrence of outbreaks among HIV-infected MSM, we believe the Advisory Committee on Immunization Practices should formally evaluate routine meningococcal vaccination in HIV-infected adults because this is not currently recommended. How should clinicians respond? During previous MSM outbreaks in Toronto and Chicago, public health officials responded rapidly with targeted vaccination campaigns that together reached 18 000 persons. Since 4 October 2012, NYC DOHMH has promoted vaccination via physician communication, advertisements on social networking mobile phone applications and Web sites used by MSM and many of the IMD cases, free vaccine administration at NYC DOHMHs sexually transmitted disease clinics, and vaccination events at MSM bars. To date, more than 11 000 people have been vaccinated and no new cases have been reported since February 2013. Community-based organizations in Los Angeles have taken a similar approach. However, vaccine coverage may be suboptimal because of challenges in reaching the populations most at risk, particularly African American MSM who may not self-identify as gay or be engaged in medical care. Primary care providers have faced barriers to vaccine delivery, including high procurement costs, limited reimbursement, and varying insurance requirements. Coverage has improved with increased media attention and clarification that insurers are mandated to cover the immunization under New York State law, but the experience highlights the logistic challenges in effectively implementing new vaccine recommendations for adults. Providers should be aware of the recent meningococcal cases in NYC and Los Angeles, assess their patients’ risk, and discuss the outbreak with their MSM patients. Suspected meningococcal cases should be reported promptly to local health departments, where patients should have an epidemiologic investigation that accounts for sexual history and determines HIV status. Several city and state health departments, including Massachusetts, Rhode Island, San Francisco, San Diego and Toronto, have recommended that MSM traveling to NYC be vaccinated. Travel recommendations are particularly important because of the upcoming Gay Pride events in NYC from 28 to 30 June 2013, with attendance expected to be as high as 1 million people. By analogy, mass gatherings, such as the hajj (the annual religious pilgrimage in Saudi Arabia), have been associated with meningococcal outbreaks, and vaccination is now required for pilgrims. Parallels have been drawn between this meningococcal outbreak and the initial reports of HIV cases in 1981 from Los Angeles and NYC. Obvious and important differences included the availability of a vaccine and acquired immunity to meningococci in a large proportion of the adult population. However, the lessons learned from the previous HIV epidemic suggest that a successful response requires the coordinated efforts of public health authorities, the government, clinicians, researchers, the pharmaceutical industry, the media, and the community. Improved understanding of the microbiologic, genetic, epidemiologic, and immunologic determinants of IMD will be necessary to prevent future outbreaks and to identify and reach those at risk.