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Evaluation of an Innovative Internet-based Partner Notification Program for Early Syphilis Case Management, Washington, DC, January 2007–June 2008

Ehlman, Daniel C. MPH*; Jackson, Marcus BA; Saenz, Gonzalo MD; Novak, David S. MSW; Kachur, Rachel MPH; Heath, John T. BA; Furness, Bruce W. MD

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Sexually Transmitted Diseases: August 2010 - Volume 37 - Issue 8 - p 478-485
doi: 10.1097/OLQ.0b013e3181e212cb
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Rates of primary and secondary syphilis in the United States fell drastically in the 1990s, prompting the Centers for Disease Control and Prevention (CDC) to launch the National Plan to Eliminate Syphilis in 1999.1 By the year 2000, syphilis rates reached their lowest point but have since increased steadily, concentrating primarily among men,1 with substantial outbreaks in men who have sex with men (MSM).2 The recent increases in syphilis among MSM have been characterized by increased numbers of sexual partners per syphilis patient compared to historical norms,2 high rates of human immunodeficiency virus (HIV), high-risk sexual activity, and use of the Internet to meet sex partners.3

In 2000, public health literature predicted the growing importance of the Internet in the transmission of syphilis and other sexually transmitted diseases (STDs).4–6 Among American Internet users, 35% reported “ever us[ing] online social or professional networking sites,” and 5% reported “ever go[ing] to a dating website or other sites … to meet people online.”7 The Internet, especially dating or sex websites, can provide users with pseudonymity2,8,9 and facilitate greater numbers of sexual encounters in shorter periods of time.10 It has been well-documented that MSM are using the Internet to find sex partners.10–14

Historically, early syphilis case management focused on contact tracing and Disease Investigation Specialist (DIS)-assisted partner notification (PN) to interrupt disease transmission.15 Recent outbreaks of syphilis among MSM have not fit the traditional model in which intensive contact tracing and partner notification can lead to the containment of the outbreak. Partner notification for MSM in 8 cities found that index patients claimed a mean of 6.8 partners; however, only a median of 14% of all partners were ever contacted by public health officials.2 Furthermore, 45% to 89% of the index patients reported anonymous partners.2

The growth of pseudonymous sexual encounters facilitated by the Internet translates into patients who are unaware of their sex partners' names, phone numbers, and physical addresses, rendering these populations impossible to reach through traditional contact tracing. From 2000 to 2004, a few public health and not-for-profit clinics began using the Internet to augment their traditional syphilis case management by electronically notifying appropriate sex partners of their exposures to syphilis.13,16,17 In 2005, the CDC encouraged the exploration of Internet interventions in STD/HIV case management and prevention efforts.18 Since then, many other health departments, including the Washington, DC, Department of Health (DCDOH), have created and implemented Internet-based Partner Notification (IPN) programs; the CDC has issued general recommendations;15 and the National Coalition of STD Directors has issued guidelines.19

The DCDOH defines IPN as the process of using Internet-locating information to provide exposure notification to the sex partners of individuals who have been diagnosed with an STD. Used in conjunction with traditional PN, IPN augments, but does not replace, traditional syphilis case management, enabling the notification in shorter periods of time of greater numbers of sex partners who would not otherwise be reached. IPN attempts to redefine anonymity on the Internet and provide a tool for public health departments to use for disease intervention in a communication medium that is acceptable to its clients.20

Limited published information has quantified the success of IPN and its impact on program-level disease intervention.8 In this article, we evaluate the first 18 months of DCDOH's IPN program for early syphilis infections using the standard CDC DIS disposition codes, as well as using DCDOH's IPN-specific outcomes for pseudonymous partners.


Study Population

The study was comprised of patients diagnosed with early syphilis infections (including primary, secondary, and early latent syphilis) who were investigated by DCDOH from January 2007 through June 2008. Per legal responsibility, providers and laboratories in Washington, DC, reported early syphilis infections and positive titers, respectively, which DCDOH investigated to determine final diagnoses. In those patients with final diagnoses of early syphilis, the DIS interviewed the patients for the purposes of confirmation of treatment, sexual risk counseling, and elicitation of sex partners (Fig. 1).

Figure 1.
Figure 1.:
STD Control Program Early Syphilis Case Investigation Process, Washington, DC, January 2007–June 2008.

PN Procedures and Investigation Classification

If the elicited sex partners had traditional locating information (e.g., name, phone number, address), the DIS pursued traditional PN via field visits and telephone conversations and closed partner investigations with the appropriate CDC DIS STD Disposition Codes, per case management protocol.21 If limited to Internet-locating information such as e-mail addresses or website screen names, then the DIS assigned PN responsibilities to the IPN Coordinator, who sent e-mails to the respective sex partners, as indicated in the DCDOH IPN protocol (Fig. 2).

Figure 2.
Figure 2.:
STD Control Program Early Syphilis IPN Investigation Classification Process, Washington, DC, January 2007–June 2008.

E-mails were sent to sex partners using both open and closed e-mail systems. Open e-mail systems allow for communication within and between e-mail networks (e.g., sending an e-mail from the DCDOH e-mail system to a Yahoo! account). Closed e-mail systems allow for communication primarily or only within one provider's network (e.g., sending an e-mail between accounts within the MSM sexual networking website Manhunt).

As many as three unsolicited IPN e-mails were sent to sex partners. A standard e-mail was used initially, regardless of syphilis stage; however, more specific language regarding syphilis exposure was sent if written authorizations were obtained from the contacted partners. If partners responded and traditional locating information was obtained, then DCDOH confirmed testing and treatment by contacting the partners' physicians and classified investigations per CDC DIS STD Disposition Codes. However, if traditional locating information could not be obtained, then testing and treatment could not be confirmed via traditional methods. For these pseudonymous partners, DCDOH created 3 IPN outcomes to classify their levels of disease exposure awareness: “Informed of Syphilis Exposure,” “Informed of General STD Exposure,” and “Not Informed or Unable to Confirm Receipt of General STD Exposure.” In closed e-mail systems, when the partner terminated or did not engage in a dialog with DCDOH, we classified the IPN outcome based on the results of websites' internal e-mail status tracking systems. For example, if the tracking indicated that an e-mail with syphilis exposure information was opened by the recipient, we classified that outcome as “Informed of Syphilis Exposure,” even though we may have not received a response from the partner. No such tracking system was available in open e-mail systems, so nonresponders were classified as “Not Informed or Unable to Confirm Receipt of General STD Exposure” (Fig. 2).

Data were tracked using modifications to Local-Use fields within STD Management Information System (STD*MIS) 4.0e (CDC, Atlanta, GA).

Analysis Procedures

We evaluated the success of IPN through analysis of DIS disposition codes and IPN outcomes. First, we focused on 3 traditional case management evaluation indices, including numbers of sex partners investigated, syphilis patients with at least one sex partner treated (preventively or because of recent infection), and sex partners medically evaluated and treated if necessary (i.e., partners may not have been preventively treated if beyond the infectious period). Second, to account for investigations in which testing and treatment could not be confirmed, we generated an additional case management evaluation index for the number of sex partners notified of STD exposure, which included all partners of traditional PN who were examined, treated, and informed but refused examination and all “informed” partners of IPN. All indices used, as the denominator, the number of syphilis patients.

All data analyses were performed using a database software, STD*MIS 4.0e, and SAS 9.1.3 (SAS Institute, Cary, NC).


Between January 2007 and June 2008, 361 case investigations of confirmed early syphilis infection were initiated by DCDOH (Table 1). Surveillance and interview data indicated that 337 (93%) were males and 24 (7%) females. The DIS attempted to contact all patients and completed interviews with 286 (79%), of which, 88 (31%) reported using the Internet to meet sex partners.

Characteristics of the 361 Patients With Early Syphilis Infection, Washington, DC, January 2007–June 2008

The median age of the total population was 35 (range: 16–61); most were men (93%), black (61%), diagnosed with secondary syphilis (51%), and diagnosed outside of the public STD clinic (87%). The 286 interviewed patients reported—or enumerated—a total of 1,196 partners, with a median of 2 (range: 0–266). Of those 286 patients, 188 (66%) provided partner information, and 888 partners were investigated. Of the 188, 27 (14%) provided Internet-locating information for at least one sex partner.

Similar to the total population, the 27 patients who provided at least one Internet partner were primarily male (100%) and black (59%), reported having sex with men (100%), and were diagnosed in the private sector (89%). In contrast, the median age was younger (31), and primary syphilis diagnoses accounted for a larger proportion (33%). For the 27 patients, 535 partners were investigated, with a median of 3 partners per patient (range: 1–237)—154 (29%) with traditional locating information and 381 (71%) with Internet-locating information.

The 381 Internet partners were sent e-mails in 4 closed e-mail systems (340 partners, or 89%) and 6 open e-mail systems (41 partners, or 11%). Of the 381 Internet partners, 65 (17%) responded to DCDOH e-mail notifications, and complete names and dates of birth were provided. Of these 65, DCDOH confirmed that 6 (9%) were infected and subsequently treated, 25 (38%) were preventively treated for exposure, 4 (6%) had been previously treated for infection, and 22 (34%) were tested and found to be uninfected (Fig. 3).

Figure 3.
Figure 3.:
Number of Internet Partner Investigations, by Investigation Outcome, Washington, DC, January 2007–June 2008.

The remaining 316 Internet partners did not provide DCDOH with traditional information to confirm testing and treatment. However, 29% (110/381) contacted DCDOH by phone or e-mail and were given syphilis disease and treatment information (Fig. 3), of which 48 reported back that they were examined and treated (one reported a recent infection).

The closed websites' e-mail status tracking systems confirmed that another 30% (116/381) received and opened DCDOH's initial e-mail informing them of a potential exposure to an STD. Despite opening these e-mails and in many cases responding to the e-mails, they did not request additional information and DCDOH did not send them syphilis-specific information.

Confirmation of e-mail receipt was not obtained for the remaining 24% of partners (90/381) because the partners used e-mail addresses on open e-mail systems (which lacked a tracking system), did not have up-to-date e-mail accounts (so e-mails were returned), did not log on to their accounts during the investigation process, ignored the e-mails, or blocked DCDOH from sending e-mails.

Analyzing the impact of the 27 patients with Internet partners on the total population of 361 patients (Table 2), IPN improved every case management index. IPN was the method used in 381 (43%) of the 888 partner investigations. Specifically, the average number of partners investigated in the 27 cases with Internet-locating information was 14.1, substantially higher than the average of 2.9 in the 176 cases with traditional locating information. Of the 100 syphilis cases with at least one treated partner, 10 (10%) included partners treated because of IPN success. IPN accounted for 53 (21%) of 257 sex partners medically examined and treated, if necessary. Furthermore, IPN accounted for 285 (45%) of 630 sex partners notified of general STD exposures.

Case Management Indices for the 361 Early Syphilis Patients, Washington, DC, January 2007–June 2008

IPN′s impact is more pronounced when focusing the analysis on the 27 patients for whom at least one Internet partner was elicited (Table 3). In those cases, IPN was the method used in 381 (71%) of the 535 investigations. Of the 13 syphilis cases with at least one treated partner, 10 (77%) included partners treated because of IPN success. IPN accounted for 53 (57%) of 93 sex partners medically examined and treated, if necessary. Furthermore, IPN accounted for 285 (78%) of 365 sex partners notified of general STD exposures.

Case Management Indices for the 27 Early Syphilis Patients Who Provided Only Internet-Locating Information for at Least 1 Partner, Washington, DC, January 2007–June 2008


We evaluated IPN outcomes of investigations from patients diagnosed with early syphilis infection and compared the results to outcomes from traditional PN. Because of the increasing number of MSM using the Internet to meet pseudonymous partners and thus the reduced proportion of partners notified by traditional PN (upwards of 86%2), we decided to establish an IPN program, a process that was less complicated than anticipated because Adam4Adam and Manhunt websites provided free public health profiles and website access was not restricted by DCDOH policies. This study found that IPN augmented traditional PN and provided a method for reaching previously untraceable sex partners. Specifically, IPN successfully notified at least 285 Internet partners who otherwise would not have been contacted.

IPN augmented case management in 14% (27/188) of all investigations where partner locating information was provided and markedly improved the overall disease intervention and new exam indices by 8% and 26%, respectively (Table 2). It is likely that the impact of IPN is underestimated in the traditional case management indices, as only 17% of DCDOH's Internet partners (65 of 381) are accounted for through those indices. In addition, IPN increased the overall total number of partners investigated by 75%, possibly because Internet users have more sex partners, are more willing to provide partner information, or both. Furthermore, given the low indices from traditional PN (e.g., only 26% of infectious syphilis cases with at least one treated partner) (Table 2), and anecdotal evidence of testing and treatment of many who remain pseudonymous, we argue that IPN′s exposure notification could significantly impact the disease intervention although we are not able to measure it using traditional indices. One private gay men's health clinic, working in conjunction with the Chicago Department of Public Health, found that once a patient was notified, there was no statistical difference between contact method (traditional PN vs. IPN) and final outcome (treated, examined, etc.).22 Further study on the impact of exposure notification is needed.

When executed properly, IPN enables the disease investigator to reach many partners in significantly less time than a field visit, which can be time-consuming. In the same time it takes to physically locate a partner, dozens of notification e-mails (if not, more) to numerous partners can be sent. After thorough training, the IPN DIS or Coordinator can manage a substantial Internet workload. In DC, for example, the IPN Coordinator carried out all IPN activities and did so at a part-time capacity. Further research should examine the cost effectiveness, especially compared to traditional DIS work.

Although this study focused on IPN to notify partners of MSM with early syphilis diagnoses, we encourage the exploration of the use of IPN for other populations and diseases. Evaluation of IPN for other diseases, including chlamydia, gonorrhea, and HIV, is of utmost importance, especially as more health departments integrate HIV and STD partner services. In this study, there were no patients who were diagnosed with both early syphilis and new HIV infections, who did not provide traditional locating information for their sex partners, perhaps because the DIS were more successful at obtaining traditional locating information from patients with a dual infection or because a majority of our IPN cases were already HIV-infected.

It is important that health departments maintain a presence online and keep abreast of changing technology (e.g., cell phone Internet platforms) and Internet trends (e.g., growing demand for and use of heterosexual dating websites and other social networking sites) to intervene when and if necessary. Most IPN programs, including DCDOH's, use the electronic communication as a tool of last resort; however, some are beginning to explore the role of IPN as a first line disease intervention technique.

Despite IPN′s success, this study highlights two important case management concerns. First, the DIS were successful in partner elicitation in only 52% of syphilis case investigations (188 of 361)—additional research should investigate the reasons for patients refusing interviews. Because public health will need many tools to interrupt disease transmission in this epidemic,23 other innovative disease intervention techniques, such as PENSHouston's online STD interview24 and inSPOT's STD notification electronic postcards,25 should be explored and evaluated. Second, the Internet's role in facilitating the spread of STDs is paramount but not yet completely understood. Since 2007, a third of interviewed male syphilis patients in DC reported using the Internet to meet sex partners, a number that likely under-represents the percentage of MSM syphilis patients who are actually using the Internet. Whereas it may not necessarily mean riskier sex practices, the use of the Internet to find sex partners can facilitate large numbers of sexual encounters in short periods of time,10 which appears to be the case in DC, meaning increased numbers of Internet sex partners and possibly the greater facilitation of sexual interactions between traditionally distinct social networks.26

Our study included the following limitations. First, only 65 (17%) of the 381 partners elicited provided their names and dates of birth, which might be due to a lack of trust of DCDOH by patients, that most partners had private medical providers and were not interested in DCDOH's partner services, or because of limited ability of the IPN Coordinator to elicit information. Second, 4 of the 27 IPN cases accounted for 300 of the 381 IPN partners, possibly affecting generalizability of the study. Third, current national case management indices do not account for the 226 (59%) partners for whom it can be confirmed receipt of notification e-mails. Thus, we created an index to measure IPN′s impact on those partners for whom traditional locating information was not obtained. Whereas the index does not measure confirmed disease intervention, it does measure the partners' disease exposure awareness, which we hypothesize positively influences behavior change (however, an additional limitation is that we classified partners who “opened” e-mails [indicated by the website tracking system] as “informed” of disease exposure although we may not have received a response from them). No similar data are known to have been collected previously, and thus, this data cannot be compared to other programs. Considering this lack of data collection, we recommend that health programs update their data collection systems, perhaps modifying their investigation disposition codes, to capture this new intervention medium.

In closing, whereas the Internet may be a new intervention tool for many health departments, it is not a new communication medium for the American public, who are increasingly integrating the Internet into many aspects of their daily lives, including searching for sexual or romantic partners.7 By embracing the Internet for STD/HIV prevention efforts, health departments broaden their reach and meet patients where they are, online. As more public health departments begin to use IPN and other Internet interventions and publish their results, acceptance of and improvement on the tools will continue to grow.


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