Distribution of Trichomonas vaginalis Among Women at High Risk for HIV Infection

1. Distribution of Trichomonas vaginalis Among Women at High Risk for HIV Infection Barbara Van Der Pol, James Williams, Jacquelyn Murphy and the Project SHIELD Collaborators

2. Epidemiology of Trichomonas Infection Over 170 million infections in women annually (WHO, 1996) Not reportable in the US Infections occur in older women Zhang, et al, STD 23:415, 1996 Dragsted, et al, STD 28:326, 2001 While this is a staggering number, more than ct & gc infections combined, it is worth noting that this represents cases in women only. In the STD clinic in Marion County Indiana, the prevalence of TV in women is roughly 20-25%. In the same clinic, the prevalence in men is less than 6%. Because infection in TV is not a reportable disease in the US, broad-based, population-level data are not readily available. Therefore, understanding the epidemiology of tv infection in the US is dependent on research projects. Few multi-center studies have included trichomonas in STD screening so very little data exists regarding the distribution of TV throughout the US Studies performed in both China and Europe have shown that trich infections appear to occur in older women than those who are infected with ct & GC. Zhang et al found the highest prevalence of tv infection in women aged 40-44 in a study of almost 17,000 women aged 25 and over in China. In Denmark, Dragsted et al actually found that the median age of women with trich infection had increased from 31 to 39 over a thirty year period of observation between 1967-1997. In this report, the median age of women with gc had also increased from 21-24 while the median age of infection with ct had remained stable at 22 y/oWhile this is a staggering number, more than ct & gc infections combined, it is worth noting that this represents cases in women only. In the STD clinic in Marion County Indiana, the prevalence of TV in women is roughly 20-25%. In the same clinic, the prevalence in men is less than 6%. Because infection in TV is not a reportable disease in the US, broad-based, population-level data are not readily available. Therefore, understanding the epidemiology of tv infection in the US is dependent on research projects. Few multi-center studies have included trichomonas in STD screening so very little data exists regarding the distribution of TV throughout the US Studies performed in both China and Europe have shown that trich infections appear to occur in older women than those who are infected with ct & GC. Zhang et al found the highest prevalence of tv infection in women aged 40-44 in a study of almost 17,000 women aged 25 and over in China. In Denmark, Dragsted et al actually found that the median age of women with trich infection had increased from 31 to 39 over a thirty year period of observation between 1967-1997. In this report, the median age of women with gc had also increased from 21-24 while the median age of infection with ct had remained stable at 22 y/o

3. Significance of Trichomonas Infection Implications of infection adverse pregnancy outcomes PID & infertility Implications in spread of HIV Increased acquisition Increased viral shedding Role in Cervical Cancer? Trichoomonas has not been a high PH priority in the past, in part because it was considered easy to diagnose in the clinic and easy to treat. The majority of the burden of disease falls on women because infections are predominately diagnosed in women and the significance of infection in men is not well understood. Obviously, adverse outcomes of pregnancy as well as upper genital tract complications have been described as associated with tv infection. However, more recent reports of the potential role of trichomonas infections in both the acquisition and transmission of HIV have resulted in a renewed awareness of the diseases, especially in populations at risk for HIV infection. It has been suggested that the recruitment of CD4+ cells into the reproductive tract could increase the potential number of susceptible cells in a trichomonas infected woman who is exposed to HIV. Conversely, Mike Cohen and others have shown an increase in genital shedding from HIV-infected men with trichomonas infections, putting their sexual partners at increased risk. Finally, in the study of Chinese women by Zhang et al, cervical cancer was the main study outcome. They found a statistical association between tv infection and cervical cancer with a RR of 3.3 in tv infected women. However, this study was performed in the 70s & 80s so the influence of HPV was not controlled for.Trichoomonas has not been a high PH priority in the past, in part because it was considered easy to diagnose in the clinic and easy to treat. The majority of the burden of disease falls on women because infections are predominately diagnosed in women and the significance of infection in men is not well understood. Obviously, adverse outcomes of pregnancy as well as upper genital tract complications have been described as associated with tv infection. However, more recent reports of the potential role of trichomonas infections in both the acquisition and transmission of HIV have resulted in a renewed awareness of the diseases, especially in populations at risk for HIV infection. It has been suggested that the recruitment of CD4+ cells into the reproductive tract could increase the potential number of susceptible cells in a trichomonas infected woman who is exposed to HIV. Conversely, Mike Cohen and others have shown an increase in genital shedding from HIV-infected men with trichomonas infections, putting their sexual partners at increased risk. Finally, in the study of Chinese women by Zhang et al, cervical cancer was the main study outcome. They found a statistical association between tv infection and cervical cancer with a RR of 3.3 in tv infected women. However, this study was performed in the 70s & 80s so the influence of HPV was not controlled for.

4. Description of Project Shield Funded by Center for Mental Health Services Evaluation of an intervention aimed at reducing HIV high-risk behaviors Longitudinal study - 0, 3 and 6 months 7 study sites are located in Florida, Georgia, Massachusetts, Rhode Island (2), Texas and Virginia Project Shield is a multi-center study design to evaluate intervention strategies in populations at high-risk for infection with HIV. It is important to note that the Indiana University laboratory is serving the project as a reference diagnostic laboratory and our group did not participate in study design, analysis design or data management. Therefore, what I will present today is based on observations regarding laboratory results and is in no way an attempt to draw any conclusions based on the overall project.Project Shield is a multi-center study design to evaluate intervention strategies in populations at high-risk for infection with HIV. It is important to note that the Indiana University laboratory is serving the project as a reference diagnostic laboratory and our group did not participate in study design, analysis design or data management. Therefore, what I will present today is based on observations regarding laboratory results and is in no way an attempt to draw any conclusions based on the overall project.

5. Project Shield, Target Populations Adolescents - male & female (15-21) have had unprotected sex within 90 days Women at high-risk (18-65) have had unprotected sex within 90 days at least one additional risk-factor All enrollees were HIV negative, not pregnant or trying to get prgnant and English speaking. Additional risk-factors include new part, multiple part, non-monog part, IDU part, HIV part, STD part, self STD, self IDU, crack use all within 90 days prior to enrollmentAll enrollees were HIV negative, not pregnant or trying to get prgnant and English speaking. Additional risk-factors include new part, multiple part, non-monog part, IDU part, HIV part, STD part, self STD, self IDU, crack use all within 90 days prior to enrollment

6. Recruitment Venues Alternative High Schools Homeless shelters Traveler�s Aid Society facilities Crack houses HUD housing units Outpatient Detox Centers

7. Laboratory Methods Urine samples were chosen for non-invasive sampling Amplified DNA testing was performed to detect Chlamydia, Gonorrhea and Trichomonas infections Laboratory observations are reported here The lab methods used for this project have been presented previously and I won�t go into great detail regarding them. I would be happy to either answer questions, or speak individually with anyone who would like any assay specific details. The major points to make about the testing are that urine was diluted in Fuji�s medium to increase the stability of the samples, samples were held at 4*C, prior to testing, and that testing was done using the Roche Amplicor CT/NG PCR with an adaptation of that assay used for TV detection. Although males are enrolled in this study, only results from female study subjects were included in this analysis.The lab methods used for this project have been presented previously and I won�t go into great detail regarding them. I would be happy to either answer questions, or speak individually with anyone who would like any assay specific details. The major points to make about the testing are that urine was diluted in Fuji�s medium to increase the stability of the samples, samples were held at 4*C, prior to testing, and that testing was done using the Roche Amplicor CT/NG PCR with an adaptation of that assay used for TV detection. Although males are enrolled in this study, only results from female study subjects were included in this analysis.

8. Sensitivity of PCR for Detection of Trichomonas Compared to Wet Prep microscopy 96% more infections identified Compared to culture 48% more infections identified Much of the work that I mentioned earlier looking at trichomonas epidemiology was based either on Wet Prep microscopy or on culture for trichomonas. We have previously described the performance of the trichomonas pcr assay and the data shown here are from evaluations performed at Indiana University using samples from our local STD clinic population As you can see the PCR assay is a major improvement over microscopy, and performs quite a bit better than the traditional gold standard of culture. Such a highly sensitive assay has obvious advantages Much of the work that I mentioned earlier looking at trichomonas epidemiology was based either on Wet Prep microscopy or on culture for trichomonas. We have previously described the performance of the trichomonas pcr assay and the data shown here are from evaluations performed at Indiana University using samples from our local STD clinic population As you can see the PCR assay is a major improvement over microscopy, and performs quite a bit better than the traditional gold standard of culture. Such a highly sensitive assay has obvious advantages

9. Prevalence of Trichomonas by State

10. Population Description Data from 1923 women at baseline 784 in POP1 ages range from 15-22, median 19 1126 in POP2, range 15-58, median 36 13 lacked age data The data presented here are from 1923 subjects� baseline visits. As was expected, there was a significant difference in ages (p<.001) when the subjects were grouped by population. The data presented here are from 1923 subjects� baseline visits. As was expected, there was a significant difference in ages (p<.001) when the subjects were grouped by population.

11. TV Prevalence at Baseline A more detailed breakdown of the study design revealed that the sites with the lower age groups were also those that had the lower prevalence of trichomonas infection. I�ve shown here the mean age of subjects enrolled in each state as well as the trichomonas prevalence. The line I�ve drawn separates those sites targeting an adolescent population from those targeting a higher-risk taking adult populationA more detailed breakdown of the study design revealed that the sites with the lower age groups were also those that had the lower prevalence of trichomonas infection. I�ve shown here the mean age of subjects enrolled in each state as well as the trichomonas prevalence. The line I�ve drawn separates those sites targeting an adolescent population from those targeting a higher-risk taking adult population

12. Preliminary Analysis Age was not a predictor of trichomonas infection in POP1 (p>.16) Age was a predictor of trichomonas infection in POP2 (p<.001) In POP2, when controlling for race and other STI, age appears to remain an independent predictor of trichomonas infection (p<.001) In the younger population, age was not a significant predictor of trichomonas infection. This is not surprising considering the smaller range of ages included in this group. Although age has been demonstrated to be a predictor of chlamydia infection, and the adolescent population is at highest risk, in this study group age was not a significant predictor of ct infection. However, in the adult population, which includes adolescents as well as older women, age was a highly significant predictor of trichomonas infection. In a very rudimentary analysis, this association appears to be independent of other risk-factors such as race and presence of other STI Based on these observations, the were pooled across populations and the significance of age as a predictor of infection remainedIn the younger population, age was not a significant predictor of trichomonas infection. This is not surprising considering the smaller range of ages included in this group. Although age has been demonstrated to be a predictor of chlamydia infection, and the adolescent population is at highest risk, in this study group age was not a significant predictor of ct infection. However, in the adult population, which includes adolescents as well as older women, age was a highly significant predictor of trichomonas infection. In a very rudimentary analysis, this association appears to be independent of other risk-factors such as race and presence of other STI Based on these observations, the were pooled across populations and the significance of age as a predictor of infection remained

13. Age Distribution of STI As seen here, the prevalence of GC at baseline in this study was fairly low and is not associated with age. The association between chlamydia infection and age has been well described. It is known that women under the age of 25 are at the highest risk for ct infection and this has driven program and policy development aimed at controlling chlamydia in the United States. In this study, we see the expected distribution of chlamydial infections with the highest prevalence in mid to late adolescence. This association was statistically significant with a p value <.001. However, the distribution of trichomonas is in sharp contrast to that of chlamydia even though the behavioral risk of acquiring these infections are the same. This association with increasing age and trichomonas infection is also statistically significant.As seen here, the prevalence of GC at baseline in this study was fairly low and is not associated with age. The association between chlamydia infection and age has been well described. It is known that women under the age of 25 are at the highest risk for ct infection and this has driven program and policy development aimed at controlling chlamydia in the United States. In this study, we see the expected distribution of chlamydial infections with the highest prevalence in mid to late adolescence. This association was statistically significant with a p value <.001. However, the distribution of trichomonas is in sharp contrast to that of chlamydia even though the behavioral risk of acquiring these infections are the same. This association with increasing age and trichomonas infection is also statistically significant.

14. Summary Older women are at increased risk for trichomonas infection Trichomonas is a useful bio-marker of STI-related risk behaviors Trichomonas is highly prevalent in populations at risk for HIV infection This analysis is preliminary only. It does not take into account any behavioral or population-wide differences that might exist between study sites. However, the association with older age and trichomonas infection appears to be quite strong. This was seen both for pooled data and for data from only those sites enrolling older subjects It is worth noting that, especially in post-adolescent populations where chlamydia and gonorrhea prevalences are low, trichomonas, because of its increased prevalence, provides an extremely useful tool in measuring sexual related risk-taking behaviors. It should also be noted and raise some level of concern, that in populations at very high risk of exposure to HIV, the prevalence of trichomonas is quite high.This analysis is preliminary only. It does not take into account any behavioral or population-wide differences that might exist between study sites. However, the association with older age and trichomonas infection appears to be quite strong. This was seen both for pooled data and for data from only those sites enrolling older subjects It is worth noting that, especially in post-adolescent populations where chlamydia and gonorrhea prevalences are low, trichomonas, because of its increased prevalence, provides an extremely useful tool in measuring sexual related risk-taking behaviors. It should also be noted and raise some level of concern, that in populations at very high risk of exposure to HIV, the prevalence of trichomonas is quite high.

15. Program/Policy Implications Trichomonas testing by highly sensitive methods should be included in routine STD screening programs that test for CT & GC Knowledge of the trichomonas distribution in populations at high risk for HIV may be useful in designing HIV control efforts Because of the data suggesting that trichomonas may play a role in the spread of HIV, and because of the high rate of disease seen in these at-risk populations, it may be advisable to include more sensitive testing for trichomonas in existing control and reduction programs. The need for trichomonas control may be even greater if additional evidence establishes a link to cervical carcinoma. The data presented here strongly argues for including a bio-marker organism that is found in the target population.Because of the data suggesting that trichomonas may play a role in the spread of HIV, and because of the high rate of disease seen in these at-risk populations, it may be advisable to include more sensitive testing for trichomonas in existing control and reduction programs. The need for trichomonas control may be even greater if additional evidence establishes a link to cervical carcinoma. The data presented here strongly argues for including a bio-marker organism that is found in the target population.

16. Future Work Additional analyses of baseline data Analysis of incident infection data Analysis of infection in males Additional epidemiological studies of trichomonas infection More stringent analysis of the baseline data are underway and will include those factors that I have mentioned were not included in this analysis Because this is a longitudinal study, data will be available regarding incident infections that will be extremely useful. It will be interesting to see if the relationship between age and infection is observed for incident as well as prevalent infections. This analysis focused on the distribution of infection in women since they carry the greatest burden of this disease. However, since trichomonas is sexually transmitted, it is essential to learn more about the presence of organisms in men. Unfortunately, only the adolescent sites enrolled males, so less data will be available regarding age distribution. Additional epi studies are clearly needed in both men and women throughout the spectrum of ages associated with sexual activity. This study has been conducted using a very specific population. Trichomonas infections in more genralizable study populations should be investigated.More stringent analysis of the baseline data are underway and will include those factors that I have mentioned were not included in this analysis Because this is a longitudinal study, data will be available regarding incident infections that will be extremely useful. It will be interesting to see if the relationship between age and infection is observed for incident as well as prevalent infections. This analysis focused on the distribution of infection in women since they carry the greatest burden of this disease. However, since trichomonas is sexually transmitted, it is essential to learn more about the presence of organisms in men. Unfortunately, only the adolescent sites enrolled males, so less data will be available regarding age distribution. Additional epi studies are clearly needed in both men and women throughout the spectrum of ages associated with sexual activity. This study has been conducted using a very specific population. Trichomonas infections in more genralizable study populations should be investigated.

17. Collaborators Larry Brown Rhode Island Hospital Ralph DiClemente Emory University M. Isabel Fernandez University of Miami Timothy Flanigan The Miriam Hospital Deborah Haller Virginia Commonwealth University Lori Leonard Johns Hopkins University Lydia O�Donnell Education Development Center, Inc William Schlenger Research Triangle Institute Barbara J Silver Center for Mental Health Services