Michael C. Samuel

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.

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 Review of Adult Mortality Due to 2009 Pandemic (H1N1) Influenza A in California

Background While children and young adults had the highest attack rates due to 2009 pandemic (H1N1) influenza A (2009 H1N1), studies of hospitalized cases noted high fatality in older adults. We analyzed California public health surveillance data to better characterize the populations at risk for dying due to 2009 H1N1. Methods and Findings A case was an adult ≥20 years who died with influenza-like symptoms and laboratory results indicative of 2009 H1N1. Demographic and clinical data were abstracted from medical records using a standardized case report form. From April 3, 2009 – August 10, 2010, 541 fatal cases ≥20 years with 2009 H1N1 were reported. Influenza fatality rates per 100,000 population were highest in persons 50–59 years (3.5; annualized rate = 2.6) and 60–69 years (2.3; annualized rate = 1.7) compared to younger and older age groups (0.4–1.9; annualized rates = 0.3–1.4). Of 486 cases hospitalized prior to death, 441 (91%) required intensive care unit (ICU) admission. ICU admission rates per 100,000 population were highest in adults 50–59 years (8.6). ICU case-fatality ratios among adults ranged from 24–42%, with the highest ratios in persons 70–79 years. A total of 425 (80%) cases had co-morbid conditions associated with severe seasonal influenza. The prevalence of most co-morbid conditions increased with increasing age, but obesity, pregnancy and obstructive sleep apnea decreased with age. Rapid testing was positive in 97 (35%) of 276 tested. Of 482 cases with available data, 384 (80%) received antiviral treatment, including 49 (15%) of 328 within 48 hours of symptom onset. Conclusions Adults aged 50–59 years had the highest fatality due to 2009 H1N1; older adults may have been spared due to pre-existing immunity. However, once infected and hospitalized in intensive care, case-fatality ratios were high for all adults, especially in those over 60 years. Vaccination of adults older than 50 years should be encouraged.

Neuraminidase Inhibitors for Critically Ill Children With Influenza

OBJECTIVE: Timely treatment with neuraminidase inhibitor (NAI) drugs appears to improve survival in adults hospitalized with influenza. We analyzed California surveillance data to determine whether NAI treatment improves survival in critically ill children with influenza. METHODS: We analyzed data abstracted from medical records to characterize the outcomes of patients aged 0 to 17 years hospitalized in ICUs with laboratory-confirmed influenza from April 3, 2009, through September 30, 2012. RESULTS: Seven hundred eighty-four influenza cases aged <18 years hospitalized in ICUs had information on treatment. Ninety percent (532 of 591) of cases during the 2009 H1N1 pandemic (April 3, 2009–August 31, 2010) received NAI treatment compared with 63% (121 of 193) of cases in the postpandemic period (September 1, 2010–September 30, 2012; P < .0001). Of 653 cases NAI-treated, 38 (6%) died compared with 11 (8%) of 131 untreated cases (odds ratio = 0.67, 95% confidence interval: 0.34–1.36). In a multivariate model that included receipt of mechanical ventilation and other factors associated with disease severity, the estimated risk of death was reduced in NAI-treated cases (odds ratio 0.36, 95% confidence interval: 0.16–0.83). Treatment within 48 hours of illness onset was significantly associated with survival (P = .04). Cases with NAI treatment initiated earlier in illness were less likely to die. CONCLUSIONS: Prompt treatment with NAIs may improve survival of children critically ill with influenza. Recent decreased frequency of NAI treatment of influenza may be placing untreated critically ill children at an increased risk of death.

Patient-delivered partner therapy for chlamydial infections: attitudes and practices of California physicians and nurse practitioners.

Objective: The objective of this study was to examine California clinicians’ use of and attitudes toward patient-delivered partner therapy (PDPT) to treat sexual partners of patients infected with chlamydia. Study Design: In 2002, a stratified random sample of primary care physicians and nurse practitioners completed a mailed, self-administered survey. Weighted frequencies were calculated to assess partner management practices, including PDPT, and attitudes toward PDPT. Multivariate models were constructed to determine independent predictors of PDPT use. Results: Of 708 physicians and 895 nurse practitioners, approximately half (47% and 48%, respectively) reported that they use PDPT usually or always. Over 90% agreed that PDPT protects patients from reinfection and provides better care for patients with chlamydia. However, providers reported concerns that PDPT may result in incomplete care for the partner, may be dangerous without knowing the partner’s medical or allergy history, is an activity the practice may not get paid for, and may get them sued. Obstetrics/gynecology and family practice physicians were more likely than internal medicine physicians to report routine use of PDPT. Concerns about adverse outcomes of PDPT were associated with less PDPT use. Conclusions: Although the proportion of California healthcare providers routinely using PDPT is comparatively high, further study is warranted to examine the circumstances under which this partner management strategy is used.

Sexually Transmitted Diseases and Risk Behaviors Among California Farmworkers: Results From a Population-Based Survey

CONTEXT The prevalence of sexually transmitted diseases and associated risk behaviors among California farmworkers is not well described. PURPOSE To estimate the prevalence of sexually transmitted diseases (STDs) and associated risk behaviors among California farmworkers. METHODS Cross-sectional analysis of population-based survey data from 6 California agricultural regions was performed for participants tested for Chlamydia trachomatis (CT), Neisseria gonorrhea (GC), and syphilis, and who completed an interviewer-administered behavioral risk factor survey. FINDINGS Among the 403 males and 234 females examined and interviewed, males (29.3%) were more likely than females (9.6%) to have had 2 or more sex partners in the past 5 years. Forty-two percent of males ever had sex with a commercial sex worker; unmarried males were more likely than married males to report sex with a commercial sex worker in the past 2 years. Twelve percent of males and 5% of females reported ever having had an STD. Most participants did not report any methods to protect against STDs. Of 192 males and 178 females tested for CT, 3 males and no females were positive. No cases of GC were found. Of 387 males and 194 females tested for syphilis, 4 males and 1 female had positive rapid plasma reagin (RPR) and Treponema pallidum particle agglutination (TPPA) results. CONCLUSIONS In this population-based survey among agricultural workers, there was low STD prevalence but high prevalence of sexual risk behaviors, particularly among males.

Neisseria gonorrhoeae and extended-spectrum cephalosporins in California: surveillance and molecular detection of mosaic penA

BackgroundThe spread of Neisseria gonorrhoeae strains with mosaic penA alleles and reduced susceptibility to extended-spectrum cephalosporins is a major public health problem. While much work has been performed internationally, little is known about the genetics or molecular epidemiology of N. gonorrhoeae isolates with reduced susceptibility to extended-spectrum cephalosporins in the United States. The majority of N. gonorrhoeae infections are diagnosed without a live culture. Molecular tools capable of detecting markers of extended-spectrum cephalosporin resistance are needed.MethodsUrethral N. gonorrhoeae isolates were collected from 684 men at public health clinics in California in 2011. Minimum inhibitory concentrations (MICs) to ceftriaxone, cefixime, cefpodoxime and azithromycin were determined by Etest and categorized according to the U.S. Centers for Disease Control 2010 alert value breakpoints. 684 isolates were screened for mosaic penA alleles using real-time PCR (RTPCR) and 59 reactive isolates were subjected to DNA sequencing of their penA alleles and Neisseria gonorrhoeae multi-antigen sequence typing (NG-MAST). To increase the specificity of the screening RTPCR in detecting isolates with alert value extended-spectrum cephalosporin MICs, the primers were modified to selectively amplify the mosaic XXXIV penA allele.ResultsThree mosaic penA alleles were detected including two previously described alleles (XXXIV, XXXVIII) and one novel allele (LA-A). Of the 29 isolates with an alert value extended-spectrum cephalosporin MIC, all possessed the mosaic XXXIV penA allele and 18 were sequence type 1407, an internationally successful strain associated with multi-drug resistance. The modified RTPCR detected the mosaic XXXIV penA allele in urethral isolates and urine specimens and displayed no amplification of the other penA alleles detected in this study.ConclusionN. gonorrhoeae isolates with mosaic penA alleles and reduced susceptibility to extended-spectrum cephalosporins are currently circulating in California. Isolates with the same NG-MAST ST, penA allele and extended-spectrum cephalosporin MICs have caused treatment failures elsewhere. The RTPCR assay presented here may be useful for the detection of N. gonorrheoae isolates and clinical specimens with reduced extended-spectrum cephalosporin MICs in settings where antimicrobial susceptibility testing is unavailable. In an era of increasing antimicrobial resistance and decreasing culture capacity, molecular assays capable of detecting extended-spectrum cephalosporin of resistance are essential to public health.

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.

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.