Increases in Gonorrhea -- Eight Western States, 2000-2005
March 16, 2007
Neisseria gonorrhoeae infection is the second most commonly reported notifiable disease in the United States.1 Gonorrhea increases the risk for pelvic inflammatory disease, infertility, ectopic pregnancy, and acquisition and transmission of human immunodeficiency virus (HIV).2 Nationally, reported gonorrhea incidence rates have been either declining or stable since 1996, although, in 2005, the national rate (115.6 cases per 100,000 population) increased for the first time since 1999.3 In recent decades, western states have had lower gonorrhea rates than other U.S. regions; however, from 2000 to 2005, rates in the West* increased 42%, from 57.2 cases to 81.5 cases per 100,000 population (Figure). During that period, rates in the three other U.S. regions decreased (South: -22%, Northeast: -16%, and Midwest: -5%). This report describes the epidemiology of gonorrhea in eight western states that reported large increases in gonorrhea incidence rates from 2000 to 2005. The results indicated that both sexes and all specified age and racial/ethnic groups experienced increases in gonorrhea rates. Causes for these increases remain unclear; however, data suggest they likely resulted from a combination of increases in the number of tests performed, trends in the types of test performed, and actual increases in disease occurrence. CDC is collaborating with state and local health departments to further investigate and respond to these increases. Public health agencies should remain vigilant for early signs of increases in gonorrhea incidence in their areas.
This analysis focused on U.S. states that reported >25% increases in the rate of gonorrhea from 2000 to 2005 and reported >500 cases of gonorrhea in 2005. Eight states met those criteria, all in the West: Alaska, California, Hawaii, Nevada, New Mexico, Oregon, Utah, and Washington. Data also were examined for two western cities, Los Angeles and San Francisco. Case report data received via the National Electronic Telecommunications System for Surveillance were examined to identify demographic trends. For each reporting area, unknown, missing, or invalid demographic data (e.g., age group or race/ethnicity) were imputed on the basis of proportions from case reports that contained known data. To assess trends in the number of males with symptomatic gonorrhea (i.e., gonococcal urethritis), during 2000-2005, clinical reports were analyzed from two of the western states (Oregon and Washington) and three cities (Honolulu, Los Angeles, and San Francisco), the only states and cities with available data on symptoms.
To examine possible causes of the increase in the gonorrhea rate in the eight states studied, data from surveys of Association of Public Health Laboratories (APHL) members conducted in 2000 and 2004 were evaluated for changes in test volume and testing technologies (i.e., the use of nucleic acid amplification tests [NAATs]). These tests detect the presence of N. gonorrhoeae DNA in cervical, vaginal, urethral, and urine samples and are more sensitive than older methods of gonorrhea detection, such as culture or nonamplified tests.4 Approximately 80% of APHL members participated in both the 2000 and 2004 surveys. The total number of gonorrhea tests and the percentage performed using NAATs in the eight western states were compared with data from the eight nonwestern states that reported the highest gonorrhea rates in 2005 (Florida, Georgia, Illinois, Michigan, New York, North Carolina, Ohio, and Texas).
The overall gonorrhea rate for the eight western states increased 52.0%, from 56.3 cases per 100,000 population in 2000 to 85.6 cases per 100,000 in 2005. The greatest increase (195.1%) was reported from Utah, where the gonorrhea rate increased from 10.3 per 100,000 population in 2000 to 30.4 in 2005. The next largest increase (103.8%) was reported from Hawaii; three other states (Alaska, California, and Nevada) had increases >50% (Table 1).
In the eight western states, increases in gonorrhea rates were observed among both sexes, in all specified age groups, and among all specified racial/ethnic populations. The gonorrhea rate among males in the eight states increased 46.7%, from 64.3 per 100,000 in 2000 to 94.5 in 2005. The gonorrhea rate among females increased 58.5%, from 52.3 per 100,000 in 2000 to 82.9 in 2005. All specified age groups had substantial increases, ranging from 43% to 64%, with the largest percentage increase among those aged 20-29 years. Although the highest gonorrhea rate in 2005 was reported among blacks (537.6 per 100,000 population in 2005), the increase among blacks from 2000 to 2005 (17.5%) was less than that for whites and Hispanics. The gonorrhea rate for whites in 2005 was 50.4 per 100,000 population, an increase of 77.5% from 2000; the rate for Hispanics in 2005 was 91.1 per 100,000 population, an increase of 80.8% from 2000.
Among 21 public health laboratories in the eight western states, the number of gonorrhea tests increased 87.1%, from 334,171 in 2000 to 625,381 in 2004. At 15 public health laboratories in the eight nonwestern states used for comparison, the number of tests increased 13.8%, from 641,068 in 2000 to 729,456 in 2004. The percentage of samples tested using NAATs increased from 49% in 2000 to 86% in 2004 in the eight western states and from 9% to 35% in the eight nonwestern states.
In Honolulu, Los Angeles, Oregon, and Washington, the number of males with symptomatic gonorrhea increased from 2000 to 2005; in San Francisco, the number declined from 2000 to 2003, but increased from 2003 to 2005 (Table 2). Changes in the numbers of males with symptomatic gonorrhea, during 2000-2005 roughly paralleled changes in the overall number of reported cases in all areas (Table 1).
Reported by: M Javanbakht, PhD, T McClain, MD, STD Program, Los Angeles County Dept of Public Health; JD Klausner, MD, CK Kent, PhD, STD Prevention and Control Svcs, San Francisco Dept of Public Health; G Bolan, MD, MC Samuel, DrPH, STD Control Br, California Dept of Health Svcs. RG Ohye, MS, VC Lee, MS, STD/AIDS Prevention Br, Hawaii Dept of Health. S Schafer, MD, D Harger, Public Health Div, Oregon Dept of Human Svcs. R Kerani, PhD, STD Control Program, Public Health, Seattle & King County; RT Rolfs, MD, T Lane, Utah Dept of Health. MR Stenger, MA, Infectious Disease and Reproductive Health, Washington State Dept of Health. L Newman, MD, HS Weinstock, MD, Div of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (proposed); JS Grant, MD, PM Barry, MD, EIS officers, CDC.
This report documents increases in reported gonorrhea cases among all ages, racial/ethnic populations, and both sexes in eight western states during 2000-2005. These increases likely resulted, in part, from increased testing and use of more sensitive tests; however, increases in the number of males with symptomatic gonorrhea, a population that generally seeks medical care spontaneously, suggest that actual increases in gonorrhea morbidity also occurred. National policies promoting increased testing for Chlamydia trachomatis infection might have increased gonorrhea testing through combined screening for both infections; however, such policies are national and would not be expected to produce greater increases in the West than in other regions of the United States. Spread of gonorrhea into high-risk networks, (e.g., methamphetamine users or incarcerated populations),5,6 reduced disease-control efforts, and changes in the organism (e.g., increasing antibiotic resistance or transmissibility) also are possible causes. Although the increases were most evident in the West, gonorrhea rates increased slightly in the Midwest and South from 2004 to 2005 (by 4.0% and 1.6%, respectively), suggesting that a similar pattern of increases might be occurring in other regions (Figure).
Data from public health laboratories indicate that changes in gonorrhea rates might have resulted from increased screening; a greater increase in testing volume was reported in the eight western states than in the eight nonwestern states with the highest gonorrhea rates. Furthermore, in 2000 and 2004, the western states used the more sensitive NAATs to a greater extent than the eight comparison states. However, other data sources suggest that changes in testing procedures and screening practices do not account for all of the observed increase. The Infertility Prevention Project (IPP) is a national program that funds the screening of chlamydia and gonorrhea in sexually active women; the majority of IPP screening occurs in family planning clinics. Washington experienced a significant increase in overall gonorrhea test positivity from 2003 (0.35% testing positive) to 2005 (0.49%) among females screened through the IPP; only NAATs were used during this period, and no major changes in screening volume or clinic participation occurred (Washington State Department of Public Health, unpublished data, 2006). IPP data for females aged 15-24 years in California and Utah also demonstrated increases in the percentage testing positive, from 0.9% in 2003 to 1.3% in 2005 in California and from 0.5% in 2003 to 0.8% in 2005 in Utah. In California, mostly NAATs were used and no major changes were observed in test technology or screening volume (California STD Control Branch and Utah Department of Health; unpublished data; 2007). IPP data from the other five western states either were unavailable (Alaska, Nevada, New Mexico, Oregon) or indicated a slight decline in gonorrhea test positivity (Hawaii).
Males with symptomatic gonorrhea generally visit health-care facilities for treatment and are less likely to be affected by changes in screening or testing practices. Although the number of males with symptomatic gonorrhea did not increase every year during 2000-2005 and the available data were limited to two states and three cities, the overall increases suggest actual increases in gonorrhea morbidity.
Unlike recent increases in syphilis,7 case report data indicate that the increases in reported gonorrhea rates do not appear to be confined predominantly to increases among men who have sex with men (MSM). The increase in reported rates has been similar in men and women, suggesting involvement of the heterosexual population. Available data from Honolulu, Oregon, San Francisco, Seattle, and Utah demonstrate marked increases in gonorrhea in both MSM and heterosexual populations (Hawaii Department of Health, Oregon Department of Human Services, San Francisco Department of Public Health, Public Health, Seattle & King County, and Utah Department of Health; unpublished data; 2006).
The findings in this report are subject to at least three limitations. First, complete surveillance data on gonorrhea were not consistently available in all states; for example, data on symptoms were only available from two states and three cities. Second, data on trends in laboratory testing, specifically test type and testing volume, were not available for private laboratories; whether trends in testing at public health laboratories were similar to trends in private laboratories is uncertain. Third, gonorrhea historically has been underreported;3 whether changes in reporting practices might have resulted in increased gonorrhea incidence rates is unclear. However, state health officials in several of the eight western states were not aware of any changes in policies that might have increased reporting during 2000-2005 (California Department of Health Services, Hawaii Department of Health, New Mexico Department of Health, Oregon Department of Human Services, Utah Department of Health, Washington State Department of Health; unpublished data; 2006).
CDC and health departments in affected areas continue to investigate whether the increases in each of the eight western states are related to similar or different phenomena. Even if the precise reason for increases in gonorrhea rates cannot be determined, these data should prompt public health departments in all states to review their gonorrhea control programs. STD program officials should remain vigilant for early signs of increases and consider improved surveillance for gonorrhea. Clinicians should screen and treat persons according to local, state, and national guidelines.8,9 Partners of patients with gonorrhea should be treated, and delivery of antibiotic therapy by patients directly to their partners (i.e., expedited partner therapy) should be considered where appropriate and permissible.9 Patients with gonorrhea should be retested 3 months after diagnosis because of a high frequency of reinfection.9 Laboratories should maintain a high level of quality control for gonorrhea testing. Increased resources for gonorrhea control programs should be considered because such increases have been associated with reductions in gonorrhea rates.10 Greater emphasis on gonorrhea control programs will be important for limiting increases in western states and preventing increases in currently unaffected areas.
Section of Epidemiology, State of Alaska; STD Control Br, D Gilson, KJ Bradbury, MPH, California Dept of Health Svcs; A Elliott, Idaho Dept of Health; P Kerndt, MD, C Higgins, MPH, STD Program, Los Angeles County Dept of Public Health; S Valway, DMD, New Mexico Dept of Health; J Simon, MSPH, Oregon Dept of Human Svcs; C Allen, Utah Dept of Health; I Risk, MPA, Salt Lake Valley Health Dept; MR Golden, MD, STD Control Program, Public Health, Seattle & King County; L Klopfenstein, STD/TB Svcs Section, Washington State Dept of Health; and R Johnson, MD, KP Kramer, MPH, R Nelson, MPH, Div of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention (proposed), CDC.
* One of four U.S. Census regions. West: Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. South: Alabama, Arkansas, Delaware, District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, and West Virginia. Northeast: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont. Midwest: Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin.
Available at www.cdc.gov/std/treatment.
This article was provided by U.S. Centers for Disease Control and Prevention. It is a part of the publication Morbidity and Mortality Weekly Report. Visit the CDC's website to find out more about their activities, publications and services.