The Where and How for Reaching Transgender Women and Men Who Have Sex with Men with HIV Prevention Services in Guatemala.

This study aims to describe the transgender women and men who have sex with men (MSM) missed through venue-based sampling and illustrate how data on venues can be used to prioritize service delivery. Respondent-driven sampling (RDS) and time-location sampling (TLS) were used concurrently in 2010 for behavioral surveillance among MSM and transgender women in Guatemala City. RDS recruits who did not frequent venues (n = 106) were compared to TLS recruits (n = 609). TLS participants recruited at different types of venues were compared. RDS recruits who did not frequent venues were less educated, less likely to identify as gay, more likely to have concurrent partners and female sexual partners. Participants recruited at NGOs, saunas, hotels, streets and parks had more partners, were more likely to receive money for sex or have concurrent partners. Prevention programs for MSM and transgender women should characterize social venues and people that frequent them and improve service coverage through venues and social networks.

2008 outbreak of Salmonella Saintpaul infections associated with raw produce.

BACKGROUND: Raw produce is an increasingly recognized vehicle for salmonellosis. We investigated a nationwide outbreak that occurred in the United States in 2008. METHODS: We defined a case as diarrhea in a person with laboratory-confirmed infection with the outbreak strain of Salmonella enterica serotype Saintpaul. Epidemiologic, traceback, and environmental studies were conducted. RESULTS: Among the 1500 case subjects, 21% were hospitalized, and 2 died. In three case-control studies of cases not linked to restaurant clusters, illness was significantly associated with eating raw tomatoes (matched odds ratio, 5.6; 95% confidence interval [CI], 1.6 to 30.3); eating at a Mexican-style restaurant (matched odds ratio, 4.6; 95% CI, 2.1 to ∞) and eating pico de gallo salsa (matched odds ratio, 4.0; 95% CI, 1.5 to 17.8), corn tortillas (matched odds ratio, 2.3; 95% CI, 1.2 to 5.0), or salsa (matched odds ratio, 2.1; 95% CI, 1.1 to 3.9); and having a raw jalapeño pepper in the household (matched odds ratio, 2.9; 95% CI, 1.2 to 7.6). In nine analyses of clusters associated with restaurants or events, jalapeño peppers were implicated in all three clusters with implicated ingredients, and jalapeño or serrano peppers were an ingredient in an implicated item in the other three clusters. Raw tomatoes were an ingredient in an implicated item in three clusters. The outbreak strain was identified in jalapeño peppers collected in Texas and in agricultural water and serrano peppers on a Mexican farm. Tomato tracebacks did not converge on a source. CONCLUSIONS: Although an epidemiologic association with raw tomatoes was identified early in this investigation, subsequent epidemiologic and microbiologic evidence implicated jalapeño and serrano peppers. This outbreak highlights the importance of preventing raw-produce contamination.

Reaching men who have sex with men: a comparison of respondent-driven sampling and time-location sampling in Guatemala City.

We present a comparison of respondent-driven sampling (RDS) and time-location sampling (TLS) for behavioral surveillance studies among men who have sex with men (MSM). In 2010, we conducted two simultaneous studies using TLS (N = 609) and RDS (N = 507) in Guatemala city. Differences in characteristics of the population reached based on weighted estimates as well as the time and cost of recruitment are presented. RDS MSM were marginally more likely to self-report as heterosexual, less likely to disclose sexual orientation to family members and more likely to report sex with women than TLS MSM. Although RDS MSM were less likely than TLS MSM to report ≥2 non-commercial male partners, they were more likely to report selling sex in the past 12 months. The cost per participant was $89 and $121 for RDS and TLS, respectively. Our results suggest that RDS reached a more hidden sub-population of non-gay-identifying MSM than TLS and had a lower implementation cost.

Hospitalized patients with 2009 H1N1 influenza in the United States, April-June 2009.

BACKGROUND: During the spring of 2009, a pandemic influenza A (H1N1) virus emerged and spread globally. We describe the clinical characteristics of patients who were hospitalized with 2009 H1N1 influenza in the United States from April 2009 to mid-June 2009. METHODS: Using medical charts, we collected data on 272 patients who were hospitalized for at least 24 hours for influenza-like illness and who tested positive for the 2009 H1N1 virus with the use of a real-time reverse-transcriptase-polymerase-chain-reaction assay. RESULTS: Of the 272 patients we studied, 25% were admitted to an intensive care unit and 7% died. Forty-five percent of the patients were children under the age of 18 years, and 5% were 65 years of age or older. Seventy-three percent of the patients had at least one underlying medical condition; these conditions included asthma; diabetes; heart, lung, and neurologic diseases; and pregnancy. Of the 249 patients who underwent chest radiography on admission, 100 (40%) had findings consistent with pneumonia. Of the 268 patients for whom data were available regarding the use of antiviral drugs, such therapy was initiated in 200 patients (75%) at a median of 3 days after the onset of illness. Data suggest that the use of antiviral drugs was beneficial in hospitalized patients, especially when such therapy was initiated early. CONCLUSIONS: During the evaluation period, 2009 H1N1 influenza caused severe illness requiring hospitalization, including pneumonia and death. Nearly three quarters of the patients had one or more underlying medical conditions. Few severe illnesses were reported among persons 65 years of age or older. Patients seemed to benefit from antiviral therapy.

Health care-associated measles outbreak in the United States after an importation: challenges and economic impact.

BACKGROUND: On 12 February 2008, an infected Swiss traveler visited hospital A in Tucson, Arizona, and initiated a predominantly health care-associated measles outbreak involving 14 cases. We investigated risk factors that might have contributed to health care-associated transmission and assessed outbreak-associated hospital costs. METHODS: Epidemiologic data were obtained by case interviews and review of medical records. Health care personnel (HCP) immunization records were reviewed to identify non-measles-immune HCP. Outbreak-associated costs were estimated from 2 hospitals. RESULTS: Of 14 patients with confirmed cases, 7 (50%) were aged ≥ 18 years, 4 (29%) were hospitalized, 7 (50%) acquired measles in health care settings, and all (100%) were unvaccinated or had unknown vaccination status. Of the 11 patients (79%) who had accessed health care services while infectious, 1 (9%) was masked and isolated promptly after rash onset. HCP measles immunity data from 2 hospitals confirmed that 1776 (25%) of 7195 HCP lacked evidence of measles immunity. Among these HCPs, 139 (9%) of 1583 tested seronegative for measles immunoglobulin G, including 1 person who acquired measles. The 2 hospitals spent US$799,136 responding to and containing 7 cases in these facilities. CONCLUSIONS: Suspecting measles as a diagnosis, instituting immediate airborne isolation, and ensuring rapidly retrievable measles immunity records for HCPs are paramount in preventing health care-associated spread and in minimizing hospital outbreak-response costs.

Coccidioidomycosis: knowledge, attitudes, and practices among healthcare providers--Arizona, 2007.

Coccidioidomycosis presumably causes ≤ 33% of community-acquired pneumonias cases, although < 15% of the patients are tested for coccidioidomycosis. We assessed healthcare providers' knowledge, attitudes, and practices regarding coccidioidomycosis diagnosis and treatment in Arizona. A survey was mailed to 7,608 eligible healthcare providers licensed by the Arizona medical, osteopathic, and nursing boards in October and December 2007. We used weights to adjust for non-response and multivariate logistic regression models to identify predictors of ≥ 70% correct regarding knowledge and treatment practices. Of 1,823 (24%) respondents, 53% were physicians, 52% were male, and the mean age was 51 years. Approximately 50% reported confidence in their ability to treat coccidioidomycosis, and 21% correctly answered all four treatment questions. Predictors of ≥ 70% correct concerning knowledge and treatment practices included always counseling patients after diagnosis (adjusted odds ratio [AOR]=4.4; 95% confidence interval [CI]: 2.8-7.1); specializing in infectious diseases (AOR=2.4; 95% CI: 1.0-5.7); and having received coccidioidomycosis continuing medical education (CME) in the last year (AOR=1.8; 95% CI: 1.2-2.6). These findings demonstrate that coccidioidomycosis CME improves knowledge of disease diagnosis and management, underscoring the need for a comprehensive coccidioidomycosis education campaign for healthcare providers in Arizona.

Enhanced surveillance of coccidioidomycosis, Arizona, USA, 2007-2008.

Coccidioidomycosis is endemic to the southwestern United States; 60% of nationally reported cases occur in Arizona. Although the Council of State and Territorial Epidemiologists case definition for coccidioidomycosis requires laboratory and clinical criteria, Arizona uses only laboratory criteria. To validate this case definition and characterize the effects of coccidioidomycosis in Arizona, we interviewed every tenth case-patient with coccidioidomycosis reported during January 2007-February 2008. Of 493 patients interviewed, 44% visited the emergency department, and 41% were hospitalized. Symptoms lasted a median of 120 days. Persons aware of coccidioidomycosis before seeking healthcare were more likely to receive an earlier diagnosis than those unaware of the disease (p = 0.04) and to request testing for Coccidioides spp. (p = 0.05). These findings warrant greater public and provider education. Ninety-five percent of patients interviewed met the Council of State and Territorial Epidemiologists clinical case definition, validating the Arizona laboratory-based case definition for surveillance in a coccidiodomycosis-endemic area.

A prolonged outbreak of Salmonella Montevideo infections associated with multiple locations of a restaurant chain in Phoenix, Arizona, 2008.

An outbreak of Salmonella serotype Montevideo infections associated with multiple locations of restaurant chain A in Phoenix, AZ, was identified in July 2008. One infected individual reported eating at a chain A catered luncheon where others fell ill; we conducted a cohort study among attendees to identify the vehicle. Food and environmental samples collected at six chain A locations were cultured for Salmonella. Restaurant inspection results were compared among 18 chain A locations. Routine surveillance identified 58 Arizona residents infected with the outbreak strain. Three chain A locations, one of which catered the luncheon, were named by two or more case patients as a meal source in the week prior to illness onset. In the cohort study of luncheon attendees, 30 reported illness, 10 of which were later culture confirmed. Illness was reported by 30 (61%) of 49 attendees who ate chicken and by 0 of 7 who did not. The outbreak strain was isolated from two of these three locations from uncooked chicken in marinade, chopped cilantro, and a cutting board dedicated to cutting cooked chicken. Raw chicken, contaminated before arrival at the restaurant, was the apparent source of this outbreak. The three locations where two or more case patients ate had critical violations upon routine inspection, while 15 other locations received none. Poor hygiene likely led to cross-contamination of food and work areas. This outbreak supports the potential use of inspections in identifying restaurants at high risk of outbreaks and the need to reduce contamination of raw products at the source and prevent cross-contamination at the point of service.

Sex work, discrimination, drug use and violence: a pattern for HIV risk among transgender sex workers compared to MSM sex workers and other MSM in Guatemala.

The risk of HIV infection is higher among transgender women and cisgender men who have sex with men (MSM) compared to the general population due in part to social and contextual factors. This study aimed to determine the prevalence and association of alcohol and drug abuse, discrimination and violence among transgender sex workers compared to cisgender male sex workers and cisgender men who had not received money for sex in Guatemala City. In 2010, transgender women and cisgender men who had had sex with men or transgender women were recruited into a cross-sectional behavioural survey. Among transgender women, 86% received money for sex in the past year. Transgender sex workers were more likely to use drugs and binge drink, three times as likely to be discriminated against and eight times as likely to be forced to have sex compared to non-sex worker men. Male sex workers were twice as likely to use illicit drugs or experience physical violence and six times as likely to experience forced sex compared to non-sex worker men. Transgender and male sex workers would benefit from harm reduction for substance use, violence prevention, response and strategies to mitigate discrimination.

Missed and delayed syphilis treatment and partner elicitation: a comparison between STD clinic and non-STD clinic patients.

BACKGROUND: Because of increases in reported syphilis, we sought to identify factors associated with missed and delayed syphilis treatment and partner elicitation interview. METHODS: We reviewed syphilis cases reported during June 1, 2006 to May 31, 2007 and conducted multivariate logistic regression analyses to determine demographic and clinical predictors of missed and delayed syphilis treatment and partner elicitation interview. RESULTS: Of 638 syphilis cases, 38 (6%) were identified as untreated cases. Median time-to-treatment was 7 days (range: 0-380) and median time-to-partner elicitation interview was 14 days (range: 0-380 days) for all case-patients. Both intervals were shorter for patients among whom syphilis was diagnosed at the STD clinic versus non-STD facilities. In multivariate analysis, diagnosis at a non-STD clinic (AOR: 2.6; 95% CI, 1.0-6.9) and having a late infection of unknown duration (AOR: 2.1; 95% CI, 1.0-4.6) were significantly associated with untreated syphilis. CONCLUSION: Time-to-treatment and time-to-partner elicitation interview were shorter for patients among whom syphilis was diagnosed at the STD clinic. For non-STD settings in Maricopa County, improvements in quality of care (i.e., timely treatment) and expeditious public health interventions (i.e., partner elicitation interview) are needed.

Profile of blood donors with serologic tests reactive for the presence of syphilis in São Paulo, Brazil.

BACKGROUND: Syphilis screening of blood donors is a common practice worldwide, but very little is known about the meaning of a positive serologic test for syphilis in blood donors and the risk profile of these donors. The aim of this study was to determine the demographic characteristics and risk behaviors of blood donors with recent and past syphilis and their implications for blood bank testing and deferral strategies. STUDY DESIGN AND METHODS: Demographic characteristics, category of donation, number of previous donations, sexual behavior, and history of sexually transmitted diseases were reviewed comparing blood donors with recent and past syphilis from January 1, 1999, to December 31, 2003. RESULTS: A total of 2439 interviews were reviewed, including 2161 (88.6%) donors with past and 278 (11.4%) with recent syphilis infection. Factors associated with recent infection included younger age (< or = 20 years odds ratio [OR], 36.5; 95% confidence interval [CI], 15.8-84.1), two previous donations (OR, 2.7; 95% CI, 1.9-3.9), male-male sex (homosexual OR, 8.2; 95% CI, 3.2-20.8; and bisexual OR, 11.4; 95% CI, 3.6-36.3), two or more partners in the past 12 months (OR, 2.3; 95% CI, 1.3-4.0), symptoms for syphilis (OR, 4.5; 95% CI, 2.8-7.1), and human immunodeficiency virus (HIV) seropositivity (OR, 39.6; 95% CI, 4.6-339.8). Community donors were also associated with recent syphilis infection (OR, 1.5; 95% CI, 1.2-1.9) compared to replacement donors. CONCLUSION: Sexual history, including male-male sex and multiple partners, were strongly associated with recent syphilis infection, which in turn was strongly associated with HIV. Continuous and vigilant surveillance that includes assessing sexual history and other factors associated with syphilis are needed to guide blood safety policies.

Prevalence of HIV infection and predictors of high-transmission sexual risk behaviors among men who have sex with men.

OBJECTIVES: We sought to determine the prevalence of HIV and novel cofactors of high-transmission-risk behavior in a probability sample of men who have sex with men (MSM). METHODS: We performed a cross-sectional telephone survey of 1976 adult MSM in San Francisco. RESULTS: We found an HIV prevalence of 25.2%. Predictors of unprotected insertive anal intercourse with a serodiscordant (not having the same HIV/AIDS serostatus) partner among HIV-infected men included use of Viagra and a greater number of partners in the past 12 months. Unprotected receptive anal intercourse with a serodiscordant partner among men not known to be HIV infected was independently associated with having lived in San Francisco for less than 1 year, use of crystal methamphetamine and amyl nitrites, a greater number of partners, and agreement with the statement, "You are less careful about being safe with sex or drugs than you were several years ago because there are better treatments for HIV now." CONCLUSIONS: Strategies to prevent HIV for urban MSM should focus on new predictors of HIV transmission.

Indicators of use of methamphetamine and other substances among men who have sex with men, San Francisco, 2003-2006.

BACKGROUND: Substance use has been associated with high-risk sexual behavior among men who have sex with men (MSM) both in the U.S. and around the world. Recent efforts by local organizations in San Francisco have specifically targeted methamphetamine use in this population. METHODS: We tracked methamphetamine and other substance use among men who have sex with men (MSM) in San Francisco from 2003 to 2006 using an indicator available in community outreach surveys of a prevention education program targeting MSM (n=4602). RESULTS: Overall, use of diverse substances tended to decrease from 2003 to 2006, many significantly so. Reported use of methamphetamine significantly decreased among HIV-negative MSM. However, methamphetamine and alcohol use during sex was associated with unprotected potentially HIV serodiscordant sex. CONCLUSION: Intensified prevention efforts to reduce methamphetamine use in San Francisco may be having some impact; however, strong associations of substance use and high-risk sex persist.

Characteristics and survival of AIDS patients with hepatitis C: the Brazilian National Cohort of 1995-1996.

BACKGROUND: As AIDS patients live longer, the management of co-morbidities becomes increasingly important. Previous studies from developed countries give conflicting results as to whether co-infection with hepatitis C virus (HCV) lowers the life expectancy of individuals with AIDS. METHODS: This retrospective cohort study was based on a medical record review of a nationally representative sample of 2821 adult AIDS cases diagnosed in 1995 and 1996 in Brazil. We compared the characteristics and survival of patients known to be positive and negative for HCV. RESULTS: A total of 833 patients received HCV testing, and the prevalence was 33%. HCV-positive patients received less intensive antiretroviral treatment. The crude mortality was greater for HCV-positive patients (hazard ratio 1.26; P = 0.04), but HCV status was not a significant predictor in a multivariate analysis that included other predictors of survival. CONCLUSION: Brazilian AIDS patients with hepatitis C have a shorter survival than those without, but this seems to be mainly as a result of their receiving less antiretroviral treatment. We cannot say whether this is because of the fear of hepatotoxicity, an inability to tolerate treatment, or for other reasons. To improve survival, these patients need optimal treatment of their HIV disease.

HIV testing patterns and unrecognized HIV infection among young Asian and Pacific Islander men who have sex with men in San Francisco.

The HIV epidemic is rising in Asian and Pacific Islander men who have sex with men (API MSM), who are often first diagnosed with HIV at a late stage of disease. We investigated the HIV testing patterns, correlates of prior testing, and awareness of HIV infection of 495 API MSM aged 18-29 years recruited from venues in San Francisco, using standardized face-to-face interviews. One quarter of participants had never tested for HIV, citing reasons such as perceived low risk, fear of results, and fear of needles. Older age, gay sexual orientation, history of sexually transmitted disease, higher lifetime number of sexual partners, and higher acculturation were significantly and independently associated with prior testing. Thirteen (2.6%) tested HIV-positive, of whom eight were unaware of their infection, five perceived themselves to be at low risk for HIV, and five reported recent UAI. These findings underscore the need to increase access to culturally appropriate and targeted HIV testing and to change perceptions of risk in this population.

Dramatic improvement in survival among adult Brazilian AIDS patients.

BACKGROUND: Since the last study of survival time among Brazilian AIDS patients, care has improved steadily, culminating in a controversial policy of universal free access to triple antiretroviral treatment since 1996. This large, national study examined how these changes have impacted survival. METHODS: Using national data for cases diagnosed in 1995 and 1996, we randomly selected 3930 adult AIDS cases from 18 cities in seven states representing all regions of Brazil. Trained abstracters reviewed medical records, determining dates of diagnosis and death or last contact, exposure category, treatment, and demographics. After review, 2821 cases met the inclusion criteria and were available for Kaplan-Meier and proportional hazards analysis. Data from the earlier study were re-analyzed for comparison. RESULTS: Median survival was 5 months for cases diagnosed in the 1980s, 18 months for those diagnosed in 1995, and 58 months for those diagnosed in 1996. Predictors of longer survival in univariate analysis included antiretroviral treatment, year of diagnosis, higher education, sexual exposure category, female sex, and Pneumocystis carinii pneumonia prophylaxis. In multivariate analysis, the predictive value of most of these was attenuated or disappeared, leaving antiretroviral treatment as the main predictor of survival. CONCLUSIONS: Survival time has increased substantially for adult Brazilian AIDS patients. The timing of these gains and analysis of the predictors of survival both indicate antiretroviral treatment as the cause. These findings demonstrate that universal access to antiretroviral treatment in a developing country can produce benefits on the same scale as in richer countries.

Gay Asian men in San Francisco follow the international trend: increases in rates of unprotected anal intercourse and sexually transmitted diseases, 1999-2002.

Worldwide, studies of men who have sex with men (MSM) report increases in HIV risk-related behavior. Less is known about trends within minority subpopulations of MSM, particularly those of Asian and Pacific Islander (A&PI) ethnicity. A&PI MSM are underrepresented among AIDS cases (2.7%) with respect to their estimated makeup in the gay community of San Francisco (4.5%). However, recent trends in unprotected anal intercourse (UAI) and sexually transmitted diseases suggest a reversal in the relative risk for HIV among A&PI MSM compared with White MSM. Starting from lower levels in 1999, UAI with multiple partners, UAI with multiple partners of unknown HIV serostatus, the incidence of male rectal gonorrhea, and the incidence of early syphilis among A&PI MSM surpassed levels among White MSM by 2002. A window of opportunity to prevent further spread of HIV among A&PI MSM may be closing.

Scale-up, retention and HIV/STI prevalence trends among female sex workers attending VICITS clinics in Guatemala.

BACKGROUND: Since 2007, Guatemala integrated STI clinical service with an HIV prevention model into four existing public health clinics to prevent HIV infection, known as the VICITS strategy. We present the first assessment of VICITS scale-up, retention, HIV and STI prevalence trends, and risk factors associated with HIV infection among Female Sex Workers (FSW) attending VICITS clinics in Guatemala. METHODS: Demographic, behavioral and clinical data were collected using a standardized form. Data was analyzed by year and health center. HIV and STI prevalence were estimated from routine visits. Retention was estimated as the percent of new users attending VICITS clinics who returned for at least one follow-up visit to any VICITS clinic within 12 months. Separate multivariate logistic regression models were conducted to investigate factors associated with HIV infection and program retention. RESULTS: During 2007-2011 5,682 FSW visited a VICITS clinic for the first-time. HIV prevalence varied from 0.4% to 5.8%, and chlamydia prevalence from 0% to 14.3%, across sites. Attending the Puerto Barrios clinic, having a current syphilis infection, working primarily on the street, and using the telephone or internet to contact clients were associated with HIV infection. The number of FSW accessing VICITS annually increased from 556 to 2,557 (361%) during the period. In 2011 retention varied across locations from 7.7% to 42.7%. Factors negatively impacting retention included current HIV diagnosis, having practiced sex work in another country, being born in Honduras, and attending Marco Antonio Foundation or Quetzaltenango clinic sites. Systematic time trends did not emerge, however 2008 and 2010 were characterized by reduced retention. CONCLUSIONS: Our data show local differences in HIV prevalence and clinic attendance that can be used to prioritize prevention activities targeting FSW in Guatemala. VICITS achieved rapid scale-up; however, a better understanding of the causes of low return rates is urgently needed.

Population size, HIV, and behavior among MSM in Luanda, Angola: challenges and findings in the first ever HIV and syphilis biological and behavioral survey.

OBJECTIVES: To conduct the first population size estimation and biological and behavioral surveillance survey among men who have sex with men (MSM) in Angola. DESIGN: Population size estimation with multiplier method and a cross-sectional study using respondent-driven sampling. SETTING: Luanda Province, Angola. Study was conducted in a large hospital. PARTICIPANTS: Seven hundred ninety-two self-identified MSM accepted a unique object for population size estimation. Three hundred fifty-one MSM were recruited with respondent-driven sampling for biological and behavioral surveillance survey. METHODS: Interviews and testing for HIV and syphilis were conducted on-site. Analysis used Respondent-Driven Sampling Analysis Tool and STATA 11.0. Univariate, bivariate, and multivariate analyses examined factors associated with HIV and unprotected sex. Six imputation strategies were used for missing data for those refusing to test for HIV. MAIN OUTCOME: A population size of 6236 MSM was estimated. Twenty-seven of 351 individuals were tested positive. Adjusted HIV prevalence was 3.7% (8.7% crude). With imputation, HIV seroprevalence was estimated between 3.8% [95% confidence interval (CI): 1.6 to 6.5] and 10.5% (95% CI: 5.6 to 15.3). Being older than 25 (odds ratio = 10.8, 95% CI: 3.5 to 32.8) and having suffered episodes of homophobia (odds ratio = 12.7, 95% CI: 3.2 to 49.6) significantly increased the chance of HIV seropositivity. CONCLUSIONS: Risk behaviors are widely reported, but HIV seroprevalence is lower than expected. The difference between crude and adjusted values was mostly due to treatment of missing values in Respondent-Driven Sampling Analysis Tool. Solutions are proposed in this article. Although concerns were raised about feasibility and adverse outcomes for MSM, the study was successfully and rapidly completed with no adverse effects.

Is the HIV sentinel surveillance system adequate in China? Findings from an evaluation of the national HIV sentinel surveillance system.

BACKGROUND: An external evaluation was conducted to assess the performance of the national HIV sentinel surveillance system (HSS), identify operational challenges at national and local levels and provide recommendations for improvement. METHODS: The United States Centers for Disease Control and Prevention's (CDC) Updated Guidelines for Evaluating Public Health Surveillance Systems were followed to assess the key attributes of HSS. Comprehensive assessment activities were conducted, including: using a detailed checklist to review surveillance guidelines, protocols and relevant documents; conducting self-administered, anonymous surveys with 286 local China CDC staff; and carrying out field observations in 32 sentinel sites in four provinces. RESULTS: China has built an extensive HSS with 1888 sentinel sites to monitor HIV epidemic trends by population groups over time. The strengths of HSS lie in its flexibility, simplicity, usefulness and increase in coverage in locations and populations. With its rapid expansion in 2010, HSS faces challenges in maintaining acceptability, timeliness, data quality, representativeness and sustainability. RECOMMENDATIONS: Implementation of the national guidelines should be standardized by strengthening training, monitoring and supervision of all staff involved, including community-based organizations. National surveillance guidelines need to be revised to strengthen data quality and representativeness, particularly to include specific instructions on HIV testing result provision, collection of identifying information, sample size and sampling methods particularly for men who have sex with men (MSM), collection of refusal information, and data interpretation. Sustainability of China's HSS could be strengthened by applying locally tailored surveillance strategies, strengthening coordination and cooperation among government agencies and ensuring financial and human resources.