Indian Journal of Sexually Transmitted Diseases and AIDS
: 2007  |  Volume : 28  |  Issue : 2  |  Page : 91--93

Prevalence of syphilis among HIV-seroreactive patients

D Turbadkar, M Mathur, S Gaikwad 
 Department of Microbiology, LTM Medical College and General Hospital, Sion, Mumbai, India

Correspondence Address:
D Turbadkar
Department of Microbiology, LTMMC, Sion, Mumbai - 400 022


Presence of genital ulcer disease facilitates human immunodeficiency virus (HIV) transmission and their ­diagnosis is essential for the proper management. Venereal Disease Research Laboratory (VDRL) test is used as a screening test for the diagnosis of syphilis. However, unusual VDRL test results have been reported in HIV-infected persons with syphilis. There are reports showing higher than expected VDRL titers as well as biological false positive in most of the studies. A negative Rapid Plasma Reagin (RPR) test or VDRL test result may not rule out syphilis in patients with HIV infection. For laboratory confirmation of syphilis, one specific Treponemal test, namely, Fluroscent Treponemal Antibody Absorption (FTA-ABS) test or Treponema Pallidum Haemagglutination Assay (TPHA) should be done along with VDRL. In the present study, 88 HIV-seropositive patients with history of high-risk behaviour were screened for syphilis by VDRL test. Out of these 88 cases, 42 (47.7%) patients were positive for TPHA and eight (9.1%) patients were reactive for VDRL in various titers. All the eight patients who were reactive for VDRL test were also positive for TPHA test. Persons with HIV infection acquired through sexual route should be screened for sexually transmitted infections (STIs), and all patients with STIs should be counselled for HIV testing. This will help in proper management of patients having STIs and HIV coinfection.

How to cite this article:
Turbadkar D, Mathur M, Gaikwad S. Prevalence of syphilis among HIV-seroreactive patients.Indian J Sex Transm Dis 2007;28:91-93

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Turbadkar D, Mathur M, Gaikwad S. Prevalence of syphilis among HIV-seroreactive patients. Indian J Sex Transm Dis [serial online] 2007 [cited 2020 Sep 18 ];28:91-93
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An emerging epidemic of human immunodeficiency virus (HIV) infection in India has made sexually transmitted infection (STI) control as one of the strategies imperative and probably the most important one to decrease HIV transmission.

The interaction of syphilis and HIV infection is complex. Epidemiological studies demonstrate that STIs, including syphilis, are associated with an increased risk for HIV infection among both homosexual and heterosexual persons. [1],[2] Presumably sexual behaviours that increase the risk for acquiring STIs also increase the risk for HIV transmission. Furthermore, ulcerations and inflammation caused by STIs are implicated as the cofactors for acquiring HIV infection. Recent data suggest that in the presence of other STIs, individuals are three to five times more likely to acquire HIV if exposed to the virus through sexual contact. [3]

Concurrent infection with Treponema pallidum and HIV presents a serious health problem. HIV alters the natural history of syphilis and response to therapy. Incidence of neurosyphilis is increased among the HIV infected persons, even when treated in recommended complete dosage. [4]

The diagnosis of syphilis may be more complicated in the HIV-infected patients. Unusual serological responses have been reported in syphilis, namely, higher than expected serologic VDRL titers. But false positive results have been reported in HIV-infected patients with syphilis and specific tests like Fluroscent Treponemal Antibody Absorption test (FTA-ABS) or Treponema pallidum Haemagglutination Assay (TPHA) would be beneficial.

Persons with HIV infection acquired through sexual contact should be tested for syphilis, because syphilis is a disease with broad range of manifestations and unusual clinical presentations, so specific laboratory diagnosis of syphilis is of great aid to clinical management of these cases. All sexually active persons with syphilis should be tested for HIV (with informed consent of the patient) for better management of the patients.

Proper treatment of syphilis will go long way in preventing HIV infection. Hence the study was undertaken to determine the prevalence of syphilis in HIV-seroreactive patients with high-risk behaviour and to correlate age, sex and clinical presenting complaints with HIV seroprevalence and prevalence of syphilis.

 Materials and Methods

The study was conducted at voluntary counselling and confidential testing centre (VCCTC), Department of Microbiology, LTM Medical College and General Hospital. All patients attending VCCTC were given a pre-test counselling regarding HIV, its route of transmission, preventive measures and treatment modalities. They were evaluated regarding their clinical history and personal behavioural profiles. Consent for HIV testing was taken. The HIV tests and interpretation were done as per NACO guidelines. All the patients irrespective of their serostatus were given reports only after the post-test counselling where by importance of behavioural changes and preventive measures were emphasised. They were referred to a physician or NGOs if required. Confidentiality of the results was maintained.

A total of 88 patients were enrolled in the study including 74 males and 14 females. Their consents were taken to perform VDRL and TPHA on the same sera samples which were collected for HIV testing.

The VDRL test was performed using modified VDRL test from Tulip diagnostics and TPHA test was performed by using Immutrep from Omega Diagnostics.


A total of 1985 adult patients attended VCCTC in 2 months' duration. Out of these, 219 were HIV seroreactive. Thus the prevalence of HIV among adult patients attending VCCTC was 11.03%. Route of HIV transmission in the 219 HIV seroreactive cases was heterosexual. Out of 219 cases, 88 were selected at random and they were counselled and consent was taken for further testing of VDRL and TPHA.

A total of 42 patients were TPHA reactive out of 88 HIV-seroreactive patients, i.e., 47% and eight were reactive by VDRL, i.e., 9.1%. Out of eight VDRL reactive patients, four had a titer of more than 1:64, two had 1:8 titer and one had 1:2 titer. All these eight VDRL reactive patients were also reactive by TPHA. A total of 34 samples were non-reactive by VDRL but positive by TPHA, and 46 samples were negative by both VDRL and TPHA [Table 1].


As syphilis is a disease with a broad range of manifestations and variable course; assessing reports of unusual clinical or laboratory finding in the HIV co-infected patients is difficult. Serological tests for Syphilis may be difficult to interpret in HIV-seropositive patients because of atypical responses such as delayed responses to both treponemal and non-treponemal test. The clinical manifestations, serological responses, efficacy of treatment and occurrence of complication of syphilis may be altered in patients co-infected with HIV.

In our study, 88 HIV-seropositive samples were processed for syphilis by VDRL and TPHA. Out of this, 10 patients had clinical manifestation of various STIs including syphilis.

Irrespective of sign and symptoms, all HIV-positive patients should have baseline VDRL screening and follow-up at 3 months, to rule out the possibility of false negative results, as seroconversion generally takes about 4-6 weeks after infection. In the course of reactive VDRL, the diagnosis of Syphilis should be confirmed by the specific treponenal test, namely, FTA-ABS or TPHA.

Present study showed that 42 were reactive by TPHA test while eight were reactive by VDRL. A negative VDRL test may not rule out syphilis in patients with HIV infection, while the sensitivity of this serologic test in diagnosing secondary syphilis is generally high. A rare case report of seronegative secondary syphilis in patients with HIV infection suggest that some patients fail to develop normal antibody response to T. pallidium . [5],[6] Therefore, in all suspected cases of syphilis two serological tests, i.e., one non-treporemal screening test, e.g., VDRL and one specific treponemal test, e.g., TPHA or FTA-ABS should be done for laboratory diagnosis of syphilis.

The specificity of non-treponemal serologic test for syphilis may be compromised in a HIV-infected person. [3],[5],[7] Very high VDRL titers of greater than 1:64 have been reported in HIV-infected patients without syphilis. This non-treponemal test detects antibodies against non-specific antigen, i.e., reagin, cardiolipin and lecithin. Many persons with HIV infection have anticardiolipin, antilecithin antibodies and polyclonal gammopathy. Thus in such cases positive VDRL test result might be biologically false positive and does not represent syphilis infection.

Serologic test for syphilis are the cornerstone in diagnosing untreated syphilis infection, even in a HIV-infected patient. Unusual serologic responses have been reported in HIV-infected persons with syphilis. Most reports involved higher than expected serologic titers, but false negative serologic result or delayed appearances of seroreactivity have also been reported. Nevertheless, both treponemal and non-treponemal serologic tests for syphilis are accurate in the majority of patients with syphilis and HIV coinfection.

Thus it is recommended that all the patients with newly diagnosed syphilis should be counselled for HIV testing. Similarly serological testing for syphilis in all patients with newly diagnosed HIV infection should be carried out.


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