A Case of Persistent and Possibly Treatment Resistant Pharyngeal Gonorrhea.

An HIV-negative man with pharyngeal gonorrhea had a positive test-of-cure (nucleic acid amplification test) result 7 days after treatment with ceftriaxone/azithromycin. Neisseria gonorrhoeae Multi-Antigen Sequencing Type 1407 and mosaic pen A (XXXIV) gene were identified in the test-of-cure specimen, and culture was negative. Retreatment with ceftriaxone 500 mg intramuscularly plus azithromycin 2 g orally yielded a negative test-of-cure result.

Crystal Clear? The Relationship Between Methamphetamine Use and Sexually Transmitted Infections.

Public health officials have cited methamphetamine control as a tool with which to decrease HIV and other sexually transmitted infections, based on previous research that finds a strong positive correlation between methamphetamine use and risky sexual behavior. However, the observed correlation may not be causal, as both methamphetamine use and risky sexual behavior could be driven by a third factor, such as a preference for risky behavior. We estimate the effect of methamphetamine use on risky sexual behavior using monthly data on syphilis diagnoses in California and quarterly data on syphilis, gonorrhea, and chlamydia diagnoses across all states. To circumvent possible endogeneity, we use a large exogenous supply shock in the US methamphetamine market that occurred in May 1995 and a later shock stemming from the Methamphetamine Control Act, which went into effect in October 1997. While the supply shocks had large negative effects on methamphetamine use, we find no evidence that they decreased syphilis, gonorrhea, or chlamydia rates. Our results have broad implications for public policies designed to decrease sexually transmitted infection rates.

Gonorrhea treatment practices in the STD Surveillance Network, 2010-2012.

BACKGROUND: Replacing oral treatments with ceftriaxone is a central component of public health efforts to slow the emergence of cephalosporin-resistant Neisseria gonorrhoeae in the United States; US gonorrhea treatment guidelines were revised accordingly in 2010. However, current US gonorrhea treatment practices have not been well characterized. METHODS: Six city and state health departments in Cycle II of the STD Surveillance Network (SSuN) contributed data on all gonorrhea cases reported in 101 counties and independent cities. Treatment data were obtained through local public health surveillance and interviews with a random sample of patients. Cases were weighted to adjust for site-specific sample fractions and for differential nonresponse by age, sex, and provider type. RESULTS: From 2010 to 2012, 135,984 gonorrhea cases were reported in participating areas, 15,246 (11.2%) of which were randomly sampled. Of these, 7,851 (51.5%) patients were interviewed. Among patients with complete treatment data, 76.8% received ceftriaxone, 16.4% received an oral cephalosporin, and 6.9% did not receive a cephalosporin; 51.9% of persons were treated with a regimen containing ceftriaxone and either doxycycline or azithromycin. Ceftriaxone treatment increased significantly by year (64.1% of patients in 2010, 79.3% in 2011, 85.4% in 2012; P = 0.0001). Ceftriaxone use varied widely by STD Surveillance Network site (from 44.6% to 95.1% in 2012). CONCLUSIONS: Most persons diagnosed as having gonorrhea between 2010 and 2012 in the United States received ceftriaxone, and its use has increased since the release of the 2010 Centers for Disease Control and Prevention STD Treatment Guidelines.

Variation in adherence to the treatment guidelines for Neisseria gonorrhoeae by clinical practice setting, California, 2009 to 2011.

BACKGROUND: Declining susceptibility of Neisseria gonorrhoeae to available antimicrobial agents has prompted repeated updates of the Centers for Disease Control and Prevention (CDC) treatment guidelines. The only regimen currently recommended as first-line treatment is dual therapy consisting of an intramuscular dose of ceftriaxone together with azithromycin or doxycycline. The objective of this analysis is to identify how adherence to the CDC guidelines varies by clinical practice setting. METHODS: A geographically representative random sample of N. gonorrhoeae cases reported from 2009 to 2011 was analyzed. Weighted generalized linear models were fit to calculate cumulative incidence ratios for receipt of non-recommended treatment regimen in relation to clinical practice setting, adjusted for age, race, and whether or not the participant was a man who has sex with men. RESULTS: Data from 3178 participants were available for analysis. Overall, 14.9% (weighted) of participants received non-recommended treatment. Among participants with gonorrhea identified by surveillance data as having received non-recommended treatment, the largest proportions were treated at private physicians' offices or health maintenance organizations (34.7% of participants receiving non-recommended treatment), family planning facilities (22.3%), and emergency departments/urgent care centers (12.8%). CONCLUSIONS: Barriers to adherence to the CDC treatment guidelines for gonorrhea seem to be experienced in a variety of clinical practice settings. Despite only moderate rates of nonadherence, interventions targeting private physicians/health maintenance organizations and family planning facilities may produce the largest absolute reductions in guideline-discordant treatment.

Neighborhoods at risk: estimating risk of higher Neisseria gonorrhoeae incidence among women at the census tract level.

BACKGROUND: The association between area-based social factors and sexually transmitted diseases has been demonstrated in numerous studies. Such associations have not previously been explored for their potential to quantify likelihood of higher transmission of gonorrhea in small geographic areas. METHODS: Aggregate census tract-level sociodemographic factors in 4 domains (demographics, educational attainment, household income, and housing characteristics) were merged with female gonorrhea incidence data from 113 counties in 10 US states. Multivariate models were constructed, and a tract-level composite gonorrhea risk index was calculated. This composite risk index was validated against gonorrhea incidence among women from 2 independent states. RESULTS: Seven tract-level factors were found to be most strongly correlated with female gonorrhea incidence: educational attainment, proportion of female headed households, annual household income below US $20,000, proportion of population non-Hispanic black, proportion of housing units currently vacant, proportion of population reporting moving in last year, and proportion of households that are nonfamily units. Composite index was highly correlated with female gonorrhea in the study area and validated with independent data. CONCLUSIONS: Social factors predict gonorrhea incidence at the census tract level and identify small areas at risk for higher morbidity. These data may be used by health departments and health care practices to develop geographically based disease prevention and control efforts. This is especially useful because gonorrhea incidence data are not routinely available below the county level in many states.

Neisseria gonorrhoeae outbreak: unintended consequences of electronic medical records and using an out-of-state laboratory-California, July 2009-February 2010.

Twenty of 37 gonorrhea cases identified during an outbreak were diagnosed at one health care organization that used an out-of-state laboratory. The results were transmitted into electronic medical records without provider notification. Delays in treatment and reporting were identified. Systems should be implemented to ensure provider notification of electronic laboratory results.

Sex, drugs (methamphetamines), and the Internet: increasing syphilis among men who have sex with men in California, 2004-2008.

OBJECTIVES: We examined primary and secondary syphilis cases among men who have sex with men (MSM) in California, and the association of methamphetamine use and Internet use to meet sex partners (Internet use) with number of sex partners. METHODS: We analyzed California surveillance data for MSM who were diagnosed with syphilis between 2004 and 2008, to assess differences in the mean number of sex partners by methamphetamine use and mutually exclusive groups of patients reporting Internet use (Internet users). RESULTS: Large proportions of patients reported methamphetamine use (19.2%) and Internet use (36.4%). From 2006 through 2008, Adam4Adam was the most frequently reported Web site statewide, despite temporal and regional differences in Web site usage. Methamphetamine users reported more sex partners (mean = 11.7) than nonmethamphetamine users (mean = 5.6; P < .001). Internet users reported more sex partners (mean = 9.8) than non-Internet users (mean = 5.0; P < .001). Multivariable analysis of variance confirmed an independent association of methamphetamine and Internet use with increased numbers of sex partners. CONCLUSIONS: Higher numbers of partners among MSM syphilis patients were associated with methamphetamine and Internet use. Collaboration between currently stand-alone interventions targeting methamphetamine users and Internet users may offer potential advances in sexually transmitted disease control efforts.

HIV testing among patients infected with Neisseria gonorrhoeae: STD Surveillance Network, United States, 2009-2010.

We used data from the STD Surveillance Network to estimate HIV testing among patients being tested or treated for gonorrhea. Of 1,845 gonorrhea-infected patients identified through nationally notifiable disease data, only 51% were tested for HIV when they were tested or treated for gonorrhea. Among the 10 geographic sites in this analysis, the percentage of patients tested for HIV ranged from 22-63% for men and 20-79% for women. Nearly 33% of the un-tested patients had never been previously HIV-tested. STD clinic patients were more likely to be HIV-tested than those in other practice settings.

Treatment with neuraminidase inhibitors for critically ill patients with influenza A (H1N1)pdm09.

BACKGROUND: Neuraminidase inhibitor (NAI) antiviral drugs can shorten the duration of uncomplicated influenza when administered early (<48 hours after illness onset) to otherwise healthy outpatients, but the optimal timing of effective therapy for critically ill patients is not well established. METHODS: We analyzed California surveillance data to characterize the outcomes of patients in intensive care units (ICUs) treated with NAIs for influenza A(H1N1)pdm09 (pH1N1). Demographic and clinical data were abstracted from medical records, using standardized case report forms. RESULTS: From 3 April 2009 through 10 August 2010, 1950 pH1N1 cases hospitalized in ICUs were reported. Of 1859 (95%) with information available, 1676 (90%) received NAI treatment, and 183 (10%) did not. The median age was 37 years (range, 1 week-93 years), 1473 (79%) had ≥1 comorbidity, and 492 (26%) died. The median time from symptom onset to starting NAI treatment was 4 days (range, 0-52 days). NAI treatment was associated with survival: 107 of 183 untreated case patients (58%) survived, compared with 1260 of 1676 treated case patients (75%; P ≤ .0001). There was a trend toward improved survival for those treated earliest (P < .0001). Treatment initiated within 5 days after symptom onset was associated with improved survival compared to those never treated (P < .05). CONCLUSIONS: NAI treatment of critically ill pH1N1 patients improves survival. While earlier treatment conveyed the most benefit, patients who started treatment up to 5 days after symptom onset also were more likely to survive. Further research is needed about whether starting NAI treatment >5 days after symptom onset may also convey benefit.

Repeat syphilis among men who have sex with men in California, 2002-2006: implications for syphilis elimination efforts.

OBJECTIVES: We examined rates of and risk factors for repeat syphilis infection among men who have sex with men (MSM) in California. METHODS: We analyzed 2002 to 2006 California syphilis surveillance system data. RESULTS: During the study period, a mean of 5.9% (range: 4.9%-7.1% per year) of MSM had a repeat primary or secondary (PS) syphilis infection within 2 years of an initial infection. There was no significant increase in the annual proportion of MSM with a repeat syphilis infection (P = .42). In a multivariable model, factors associated with repeat syphilis infection were HIV infection (odds ratio [OR] = 1.65; 95% confidence interval [CI] = 1.14, 2.37), Black race (OR = 1.84; 95% CI = 1.12, 3.04), and 10 or more recent sex partners (OR = 1.99; 95% CI = 1.12, 3.50). CONCLUSIONS: Approximately 6% of MSM in California have a repeat PS syphilis infection within 2 years of an initial infection. HIV infection, Black race, and having multiple sex partners are associated with increased odds of repeat infection. Syphilis elimination efforts should include messages about the risk for repeat infection and the importance of follow-up testing. Public health attention to individuals repeatedly infected with syphilis may help reduce local disease burdens.

A novel risk factor for a novel virus: obesity and 2009 pandemic influenza A (H1N1).

BACKGROUND: many critically ill patients with 2009 pandemic influenza A (H1N1) (2009 H1N1) infection were noted to be obese, but whether obesity, rather than its associated co-morbidities, is an independent risk factor for severe infection is unknown. METHODS: using public health surveillance data, we analyzed demographic and clinical characteristics of California residents hospitalized with 2009 H1N1 infection to assess whether obesity (body mass index [BMI] ≥ 30) and extreme obesity (BMI ≥ 40) were an independent risk factor for death among case patients ≥ 20 years old. RESULTS: during the period 20 April-11 August 2009, 534 adult case patients with 2009 H1N1 infection for whom BMI information was available were observed. Two hundred twenty-eight patients (43%) were ≥ 50 years of age, and 378 (72%) had influenza-related high-risk conditions recognized by the Advisory Committee on Immunization Practices as risk factors for severe influenza. Two hundred and seventy-four (51%) had BMI ≥ 30, which is 2.2 times the prevalence of obesity among California adults (23%) and 1.5 times the prevalence among the general population of the United States (33%). Of the 92 case patients who died (17%), 56 (61%) had BMI ≥ 30 and 28 (30%) had BMI ≥ 40. In multivariate analysis, BMI ≥ 40 (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.4-5.9) and BMI ≥ 45 (OR, 4.2; 95% CI, 1.9-9.4), age ≥ 50 years (OR, 2.1; 95% CI, 1.2-3.7), miscellaneous immunosuppressive conditions (OR, 3.9; 95% CI, 1.6-9.5), and asthma (OR, 0.5; 95% CI, 0.3-0.9) were associated with death. CONCLUSION: half of Californians ≥ 20 years of age hospitalized with 2009 H1N1 infection were obese. Extreme obesity was associated with increased odds of death. Obese adults with 2009 H1N1 infection should be treated promptly and considered in prioritization of vaccine and antiviral medications during shortages.

Acute Fulminant Cerebral Edema: A Newly Recognized Phenotype in Children With Suspected Encephalitis.

BACKGROUND: Encephalitis is a severe neurological syndrome associated with significant morbidity and mortality. The California Encephalitis Project (CEP) enrolled patients for more than a decade. A subset of patients with acute and fulminant cerebral edema was noted. METHODS: All pediatric encephalitis patients with cerebral edema referred to the CEP between 1998 and 2012 were reviewed. A case definition was developed for acute fulminant cerebral edema (AFCE) that included the CEP case definition for encephalitis and progression to diffuse cerebral edema on neuroimaging and/or autopsy, and no other recognized etiology for cerebral edema (eg, organic, metabolic, toxin). Prodromic features, demographic and laboratory data, neuroimaging, and outcomes were compared with non-AFCE encephalitis cases. RESULTS: Of 1955 pediatric cases referred to the CEP, 30 (1.5%) patients met the AFCE case definition. The median age for AFCE and non-AFCE cases was similar: 8.2 years (1-18 years) and 8.0 years (0.5-18 years), respectively. Asian-Pacific Islanders comprised a larger proportion of AFCE cases (44%) compared with non-AFCE cases (14%, P < .01). AFCE cases often had a prodrome of high fever, vomiting, and profound headache. Mortality among AFCE patients was significantly higher than among non-AFCE patients (80% vs 13%, P < .01). A confirmed etiology was identified in only 2 cases (enterovirus, human herpes virus type 6), while 10 others had evidence of a respiratory pathogen.Thirty pediatric patients referred to the California Encephalitis Project with a unique, and often fatal, form of encephalitis are reported. Demographic and clinical characteristics, possible etiologies and a proposed case definition for acute fulminant cerebral edema (AFCE) are described. CONCLUSIONS: AFCE is a recently recognized phenotype of encephalitis with a high mortality. AFCE may be triggered by common pediatric infections. Here, we propose a case definition.

A closer look at age: deconstructing aggregate gonorrhea and chlamydia rates, California, 1998-2007.

BACKGROUND: Risk of gonorrheal (GC) and chlamydial (CT) infection is highly associated with age. Case rates typically are reported in 5-year categories. Highest rates are seen consistently in the 15- to 19-year and 20- to 24-year age groups for both genders. It is not clear how aggregate, age-specific rates mask finer differences in risk by single age across and within racial/ethnic groups. METHODS: California case-based surveillance data for 1998 through 2007 were used to calculate GC and CT rates by single age at diagnosis. The distribution of single gender and age-specific rates was compared with 5-year age-specific rates. Descriptive statistics for age by race/ethnicity were calculated, and trends over time were assessed. RESULTS: Female, single-age-specific GC and CT rates for 2007 increased strikingly during adolescence and then declined quickly. Male, single-age-specific GC rates declined more gradually than did CT rates. The rate for the aggregate 15- to 19-year-old age group fit the single-age rates poorly, particularly for females, who in 2007 had a peak rate at age 19 for GC (497 per 100,000) and for CT (3640 per 100,000), though the highest aggregate rate was for ages 20 to 24. Blacks had the youngest mean age for both GC and CT. Mean ages increased significantly from 1998 through 2007 for female GC and CT cases, as well as for male CT cases. CONCLUSIONS: Age and race/ethnicity data should be examined in finer detail than the 5-year aggregate data, in order to target sexually transmitted disease prevention and control interventions more effectively.

Socioeconomic gradients in sexually transmitted diseases: a geographic information system-based analysis of poverty, race/ethnicity, and gonorrhea rates in California, 2004-2006.

OBJECTIVES: We quantified the relationship between gonorrheal infection rates in California and a measure of poverty status and investigated how this relationship and the spatial dispersion of cases varied among the 4 dominant racial/ethnic groups in the state. METHODS: We geocoded gonorrhea cases reported in California between 2004 and 2006, and estimated the poverty status of each case by using the percentage of residents living below poverty in the census tract of residence. We calculated infection rates for African American, Asian, Hispanic, and White cases in each of 4 poverty strata. We mapped cases to visualize the patterns of spatial dispersion associated with each race/ethnicity-poverty combination. RESULTS: There was a strong positive relationship between poverty and infection, but racial/ethnic disparities in infection, driven by a disproportionate level of gonorrhea among African Americans, eclipsed this differential. The degree of spatial aggregation varied substantially among groups and was especially pronounced for African Americans with gonorrhea in the highest poverty category. CONCLUSIONS: Prevention efforts should target low-income neighborhood "hot spots" to reach the largest numbers of cases, particularly among African Americans.

Assessment of the Association of Chlamydia trachomatis Infection and Adverse Perinatal Outcomes with the Use of Population-Based Chlamydia Case Report Registries and Birth Records.

OBJECTIVE: We assessed the relationship between Chlamydia trachomatis (CT) infections identified during pregnancy and adverse perinatal birth outcomes (including premature rupture of membranes, preterm delivery, and low birthweight) by matching CT reports and birth records. METHODS: We merged California birth records from 1997, 1998, and 1999 with California CT reports from the same years to determine the proportion of birth records matched to a female CT report, using maternal last name, first name, date of birth, and county of residence. We used logistic regression to assess the crude and adjusted association between a CT report less than 10 months before the birth record date and premature rupture of membranes, preterm delivery, and low birthweight. These results were adjusted for age, race/ethnicity, level of education, and prenatal care. RESULTS: Of 675,786 birth records and 101,296 female CT reports, 14,039 women had a CT case report and a birth record; 10,917 birth records (1.6%) were matched to a CT report during pregnancy, and 10,940 (10.8%) of CT reports were matched to a birth record date 10 months after date of diagnosis/report. For premature rupture of membranes, the adjusted odds ratio (AOR) was 1.2, 95% confidence interval (CI) 1.0, 1.3; for low birthweight, the AOR was 1.2, 95% CI 1.1, 1.3. The reduction in birthweight associated with prenatal CT infection was 31.7 grams. CONCLUSIONS: The increased risk of adverse perinatal outcomes associated with prenatal CT infection supports current prenatal CT screening guidelines. Matching of surveillance and vital statistics data sources was an efficient method to assess this association.

California Gonorrhea Surveillance System: Methodologic Aspects and Key Results of a Sample-Based System.

OBJECTIVES: This article describes findings from the California Gonorrhea Surveillance System (CGSS), developed in response to the need for detailed risk behavior data and clinical data required to control increasing gonorrhea (GC) infections in California. METHODS: CGSS is a sample-based surveillance system implemented throughout California in 2007. In 34 of 61 local health jurisdictions (LHJs), 10% of GC cases are sampled for interview; in the other 27 LHJs, all cases are followed. A standardized case investigation record collects case-reported risk data and provider-reported clinical data, and is electronically prepopulated with available contact data. Exclusion criteria include age younger than 14 years, a GC diagnosis within the previous 30 days, and provider request that patient not be contacted. Analyses are weighted to account for sample design. RESULTS: In 2007, 31,192 cases of GC were reported in California. Of these, 5,388 were sampled for follow-up and 2,715 were interviewed, for a response rate of 54.2%. Of those interviewed, 49.6% were female, 28.8% were heterosexual males, and 21.6% were men who have sex with men (MSM). CGSS collects a wide range of behavioral and clinical data for targeted programmatic action. Findings from the 2007 CGSS included data on the following areas: incarceration (highest among heterosexual males [22.4%]); methamphetamine use (high overall [12.2%] and lower among African Americans [4.6%]); co-infection with human immunodeficiency virus (high among MSM [31.9%] and very low among heterosexual males and females [<0.5%]); and improper antibiotic use (8.3% overall; 25.6% among patients attending urgent care clinics). CONCLUSION: CGSS, an innovative sample-based surveillance system, is effective and flexible. The system provides actionable data on an ongoing basis.

Practical Considerations for Matching STD and HIV Surveillance Data with Data from Other Sources.

Data to guide programmatic decisions in public health are needed, but frequently epidemiologists are limited to routine case report data for notifiable conditions such as sexually transmitted diseases (STDs) and human immunodeficiency virus (HIV). However, case report data are frequently incomplete or provide limited information on comorbidity or risk factors. Supplemental data often exist but are not easily accessible, due to a variety of real and perceived obstacles. Data matching, defined as the linkage of records across two or more data sources, can be a useful method to obtain better or additional data, using existing resources. This article reviews the practical considerations for matching STD and HIV surveillance data with other data sources, including examples of how STD and HIV programs have used data matching.

Factors associated with death or hospitalization due to pandemic 2009 influenza A(H1N1) infection in California.

CONTEXT: Pandemic influenza A(H1N1) emerged rapidly in California in April 2009. Preliminary comparisons with seasonal influenza suggest that pandemic 2009 influenza A(H1N1) disproportionately affects younger ages and causes generally mild disease. OBJECTIVE: To describe the clinical and epidemiologic features of pandemic 2009 influenza A(H1N1) cases that led to hospitalization or death. DESIGN, SETTING, AND PARTICIPANTS: Statewide enhanced public health surveillance of California residents who were hospitalized or died with laboratory evidence of pandemic 2009 influenza A(H1N1) infection reported to the California Department of Public Health between April 23 and August 11, 2009. MAIN OUTCOME MEASURE: Characteristics of hospitalized and fatal cases. RESULTS: During the study period there were 1088 cases of hospitalization or death due to pandemic 2009 influenza A(H1N1) infection reported in California. The median age was 27 years (range, <1-92 years) and 68% (741/1088) had risk factors for seasonal influenza complications. Sixty-six percent (547/833) of those with chest radiographs performed had infiltrates and 31% (340/1088) required intensive care. Rapid antigen tests were falsely negative in 34% (208/618) of cases evaluated. Secondary bacterial infection was identified in 4% (46/1088). Twenty-one percent (183/884) received no antiviral treatment. Overall fatality was 11% (118/1088) and was highest (18%-20%) in persons aged 50 years or older. The most common causes of death were viral pneumonia and acute respiratory distress syndrome. CONCLUSIONS: In the first 16 weeks of the current pandemic, the median age of hospitalized infected cases was younger than is common with seasonal influenza. Infants had the highest hospitalization rates and persons aged 50 years or older had the highest mortality rates once hospitalized. Most cases had established risk factors for complications of seasonal influenza.

Case-control study of shigellosis in San Francisco: the role of sexual transmission and HIV infection.

BACKGROUND: Shigella species infect approximately 450,000 persons annually in the United States. Person-to-person transmission of Shigella species, which have a low infectious dose, occurs frequently, particularly in areas with poor sanitation and hygiene. Sexual transmission of Shigella species among men who have sex with men (MSM) has been inferred from outbreaks of shigellosis among that population, and limited studies have suggested the importance of human immunodeficiency virus (HIV) infection as a risk factor for shigellosis. No population-based study of sporadic shigellosis has evaluated the role of sexual practices (especially among MSM) and HIV infection along with other established risk factors for shigellosis. METHODS: We conducted a population-based case-control study of shigellosis in adults in San Francisco, California, during the period 1998-1999. Cases of Shigella infection were identified through laboratory-based active surveillance conducted by the California Emerging Infections Program. Seventy-six case patients were matched by sex with 146 control subjects. Exposure data were collected on established risk factors, sexual practices, and HIV infection status. Bivariable and multivariable analyses were conducted. Population-attributable fractions were calculated. RESULTS: From the multivariable analysis, for men, shigellosis was associated with MSM (odds ratio [OR], 8.24; 95% confidence interval [CI], 2.70-25.2), HIV infection (OR, 8.17; 95% CI, 2.71-24.6), direct oral-anal contact (OR, 7.50; 95% CI, 1.74-32.3), and foreign travel (OR, 20.0; 95% CI, 5.26-76.3), with population-attributable fractions of 0.72, 0.42, 0.31, and 0.18, respectively. For women, shigellosis was associated only with foreign travel (OR, 21.0; 95% CI, 2.52-899), with a population-attributable fraction of 0.37. CONCLUSIONS: Among MSM, shigellosis is predominantly a sexually transmitted disease, with direct oral-anal contact conferring the highest risk and HIV infection likely contributing to increased host susceptibility.

Listeria monocytogenes infection from foods prepared in a commercial establishment: a case-control study of potential sources of sporadic illness in the United States.

BACKGROUND: Listeria monocytogenes has been estimated to cause >2500 illnesses and 500 deaths annually in the United States. Efforts to reduce foodborne listeriosis have focused on foods frequently implicated in outbreaks. Potential sources for L. monocytogenes infection not associated with outbreaks remain poorly understood. METHODS: The Foodborne Diseases Active Surveillance Network conducts surveillance for culture-confirmed listeriosis at clinical laboratories in 9 states. After excluding outbreak-associated cases, we attempted to enroll eligible case patients with L. monocytogenes infection in a case-control study from 2000 through 2003. Control subjects were recruited through health care providers and were matched to case patients by state, age, and immunosuppression status. Data were collected about exposures occurring in the 4 weeks before specimen collection from the case patients. RESULTS: Of the 249 case patients with L. monocytogenes infection, only 12 (5%) had cases that were associated with outbreaks; 6 other patients were ineligible for other reasons. Of 231 eligible case patients, 169 (73%) were enrolled in the study. We classified 28 case patients as having pregnancy-associated cases. We enrolled 376 control subjects. In multivariable analysis, L. monocytogenes infection was associated with eating melons at a commercial establishment (odds ratio, 2.6; 95% confidence interval, 1.4-5.0) and eating hummus prepared in a commercial establishment (odds ratio, 5.7; 95% confidence interval, 1.7-19.1). CONCLUSIONS: Most cases of L. monocytogenes infection were not associated with outbreaks. Reducing the burden of foodborne listeriosis may require interventions directed at retail environments and at foods, such as melons and hummus, that are not commonly recognized as high risk. Because of the severity of listeriosis, pregnant women and other persons at risk may wish to avoid eating these newly implicated foods.