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Indian Journal of Community Medicine

Prevalence of Sexually Transmitted Infections in Sex Workers of Surat City

Author(s): H. G. Thakor, J. K. Kosambiya, D. N. Umrigar, V. K. Desai

Vol. 29, No. 3 (2004-07 - 2004-09)


Research Question: What is the prevalence of sexually transmitted infection (STIs) in sex workers? What are the contributing socio-demographic behavioural factors?

Objective: To study the prevalence of STIs in sex workers. To find the association of different socio-demographic behavioural factors with STIs.

Study design: Cross-sectional. Setting: Red Light Area (RLA). Participants: Sex workers (SWs) residing in RLA.

Sample Size: 118. Study variables: Prevalence of STIs, age, literacy, number of partners, income, condom use, age at first sexual intercourse, past history of STDs.

Outcome variables: Association between prevalence of STIs and different socio-demographic factors (Odds Ratio)

Statistical analysis: Percentages, Chi square test. Results: Most sex workers (SWs) were illiterate, joined the work before the age of 20 years and had more than three partners per day. Condom was regularly used with the clients but not with the consistent partners. 47.5% had one or more STDs. Prevalence of syphilis was highest (22.7%). STI prevalence was higher in SWs who were more than 25 years age, literate, had first sexual intercourse before the age of 20 years, having upto 5 partners per day, having past history of STD and no treatment taken as compared to the group not having that factor, but the difference was statistically not significant. In such core group the sex work itself appears to be major risk factor masking other confounders.

Keywords: STI, HIV, Sex workers, KABP survey, Risk behaviour, Risk score


Sexually transmitted infections (STIs) including HIV continue to present major health, social and economic problems in the developing world, leading to considerable morbidity, mortality and stigma1. The prevalence rates apparently are far higher in developing countries where STD treatment is less accessible2.

Strong epidemiological association between HIV and other STDs is noted in epidemilogical studies2-5. The annual incidence of STDs in India is estimated at 5%, which indicates that approximately 40 million new infections occur every year3. Marked variation has been observed among the studies that have been conducted so far in terms of patterns and levels of morbidity.

Unsafe sexual practices, recurrent STDs, multiple STDs, asymptomatic STDs and poor access to health care facilities contributes to high rates of STDs and HIV in SWs2. Sex worker is the core group for transmission of STDs and HIV through 'bridge group' to the general population2. Accordingly, high priority is given to this group in targeted intervention for prevention of HIV/AIDS2.

To design effective STI care services towards HIV/AIDS prevention among SWs, it is necessary to study the prevalence of common STIs and the proportion of asymptomatic infections. To design locally appropriate syndromic treatment guidelines for this high - risk group, knowledge about etiologies of STIs, symptoms and the associated risk factors is essential. WHO has placed emphasis on integrated approaches using a syndromic approach for case measurement and management. It is advocated for use particularly in high prevalence areas having inadequate laboratory facilities, trained staff and transport facilities2. While the risk assessment for the management of reproductive tract infecton has many limitations, further work on risk assessment and prevalence based screening studies is necessary to evaluate the performance of syndromic management as well as to identify the associated predicting factors.

Material and Methods

This study was conducted amongst the sex workers of Red light area (RLA) of Surat, where Department for International Development (UK) funded project “Partnership in sexual health (PSH)” is in operation by the Community Medicine department of Government Medical College, Surat since 1998.

Free and voluntary informed consent was obtained from all the participants, retaining their right to withdraw at any time. Personal privacy and confidentiality was respected at all the times.

Before the implementation, national and international experts on STDs and Microbiology trained the staff involved in the survey. A trial run was conducted. Based on the trial run experience, some modifications were made for the final survey. The survey was conducted from February to September, 2000.

It was decided to enroll about 200 SWs, which comes to around one third of their population in the area, considering the feasibility and minimum sample size and likelihood of missing data. However, due to unexpected events (temporary migration of sex workers) only 124 SWs of the Red light area could be enrolled for this study. Out of this, 118 co-operated for clinical and laboratory survey. The SWs in this area live in different ethnic clusters based on place of origin, language spoken etc. Participants were chosen from each of these clusters. Health camp approach was undertaken to choose the participants.

Treatment for the symptomatic cases and a relief following the same was the additional motivation for those who were hesitant.

Procedure in the clinic After the informed consent in presence of a witness, all the consenting participants were administered a KABP schedule in which general information along with the knowledge and the behaviour related to STD, was recorded. This was followed by clinical examination and specimen collection by concerned specialists.

STDs screened Syphilis, gonorrhoea, genital chlamydial infection and trichomoniasis as well as the HIV and HSV were screened by laboratory tests. These STDs were given priority for screening because the prevalence of these STDs is high and majority of them are curable. They are often asymptomatic among women and cause considerable morbidity and mortality. The details of the methodology are described elsewhere7. Results of the additional specimens collected from the 10 participants for cross checking were compared. STD syndromes were treated following the NACO/WHO flowcharts and other diseases were treated or referred to appropriate centres for treatment. Follow up treatment was given after the laboratory results were available. Individual variation in measurement was kept minimal by involving the same team of doctors and the laboratory for examination and testing.

The Epi Info package (software) was used to design the questionnaire and for record and data analysis. The association between various socio- Deptt. of Community Medicine, Government Medical College, Surat demographic behavioural factors and the prevalence of STIs was examined by calculating Odds ratio and Chi square values.


About two-third of them were below the age of 30 yrs including 4.8% below the age of 20 years. 81.5% of them never went to school, while 13% of them were having primary/high school level education. Except 3, all of them had come from outside Gujarat and about 33.9% were from Nepal. 51% reported that they were married. About one third (36.3%) of them gave history of travelling to other cities also for sex work. Amongst those who gave history of travelling to other cities for sex work, two-third (77.8%) travelled to Maharashtra, (mainly Mumbai) and about 13.3% had travelled to Kolkata.

Table I : Distribution of Sex Workers According to Various Socio- Demographic and Behavioural Factors (n=124)

Socio-demographic/behavioural factors No (%)
Age group (years)
16-20 6 (4.8)
21-25 37 (29.8)
25-30 41 (33.1)
31-35 23 (18.5)
>35 9 (7.3)
Age not reported 8 (6.5)
Age (yrs.) of joining professional sex work
<15 21 (16.9)
16-20 39 (31.5)
21-25 43 (34.7)
>25 21 (16.9)
Age (yrs.) at first sexual intercourse
<15 41 (33.1)
16-20 54 (43.5)
21-25 25 (20.2)
>25 4 (3.2)
Average no. of partners per day
<2 12 (9.7)
3-5 75 (60.5)
6-10 33 (26.6)
11-25 4 (3.2)
Use of condom
Never/occasionally 0 (0.0)
Sometimes 2 (1.6)
Most of the times 5 (4.0)
All the times 117 (94.4)
Symptoms during last 12 months
Pain in lower abdomen 33 (26.6)
Frequent painful urination 23 (18.5)
Abnormal vaginal discharge 23 (18.5)
Pain during intercourse 15 (12.1)
lcers/sores in genital area 10 (8.1)
Swelling in groin 4 (3.2)
Didn't have any symptom 52 (41.9)
Treatment seeking behaviour
Do nothing 12 (9.7)
Took medicine from treatment provider 29 (23.4)
Took medicine from chemist 17 (13.7)
No response 66 (53.2)

As per sexual and reproductive history, majority of the SWs (83.1%) joined the profession before the age of 25 years. More than three fourth of them had their first sexual intercourse before the age of 20 years and amongst them 48.4% were in profession before they crossed the age of 20 years. About 90% of them had more than two sexual partners per day. On the last day of their work 55% of them earned less than 100 rupees, 30.6% Rs. 100 to 200, 12% Rs. 200-400 and only 2% of them earned more than Rs. 400/-.

Almost all of them (94.4%) informed that their clients regularly used condom and 96.8% of them confirmed the use of condom duirng their last sexual interaction. As per 91.9% participants, they themselves suggested the use of condom to their clients and 79.8% of them said that they themselves helped to put the condom on. 23.4% of SWs had regular partners and out of them 44.8% used condom all the times and 41.4% never used it, while 10.3% used it sometimes during the sexual intercourse with their regular partners. 3.4% gave no answer to this question. 114 (91.9%) of them had never heard about the female condom. To prevent pregnancy, 62.9% used condom, 17.7% got sterilized and 7.3% used oral pills.

91.9% of SWs were aware of the fact that certain discases are spread through unsafe sexual intercourse. The symptomatology of STDs in men was not known to 15.3% and that in women to 11.3% of SWs. About 42% of SWs had no past history of any symptom related to STDs in last 12 months. Common symptoms in past among them were pain in lower abdomen (26.6%), frequent painful urination (18.5%), abnormal vaginal discharge (18.5%) and pain during intercourse (12.1%). Regarding treatment of symtpoms in the past, 9.7% of them did nothing; 23.4% took medicine from treatment providers and 13.7% from a chemist (Table I).

Present prevalence of STIs:

Most common syndromic diagnosis was genital discharge syndrome - GDS (51.3%), followed by pain in lower abdomen (20.2%), enlarged inguinal lymph nodes (11.8%) and genital ulcer syndrome GUS (5.9%).

Table II: Laboratory Findings: Prevalence of STIs Among SWs (n=118)

STIs Test performed Result (Positive/reactive) 95%
    No. %  
Syphills(n=119) RPR test 35 (29.4)  
  TPHA test 51 (42.9)  
  RPR & TPHA test 27 (22.7) 15.16-30.21
Gonorhoea Gram stain 18 (15.3)  
  Culture in MTM media 20 (16.9) 10.18-23.72
  PACE 2 GC Assay 12 (10.2)  
Chlamydia PACE2 Chalmydia trachomatis (CT) assay 10 (8.5) 3.45-13.5
Trichomoniasis Wet mount microscopy 16 (13.6) 8.07-20.74
  Culture in Whittington media 17 (14.4) 8.07-20.74
Herpes simplex virus Tzank test 1 (0.8) 0-1.6
HIV Double ELISA test (HIV 1 and 2) 51 (43.2) 34.28-52.16
Gonorrhoea/Genital/chlamydia Culture for NG and/or PACE 2 24 (20.3) 10.75-29.85
CT Gonorrhoea/Chlamydia Trichomoniasis Presence of any one or more of the three 38 (32.2) 21.11-43.30
Gonorrhoea/Chlamydia/Trichmoniasis/Syphills/HSV Presence of any one or more of the five 56 (47.5)  

Laboratory confirmation study was done in 118 to study the prevalence of microbial infections. Based on the laboratory reports 62(52.5%) SWs had no STD (excluding HIV tests). 47.5% of them had one or more STDs. The prevalence of syphilis was 22.7%, Gonococcal infection 16.9%, Chlamydia 8.5% and Trichomonial infection 14.4%7. Overall prevalence of HSV was 0.8% (out of 7 samples taken from genital ulcer 1 was positive). HIV sero-prevalence (anonymus, double ELISA testing) was 43.2%7.

Table III : Prevalence of STDs in SWs According to Various Socio-Demographic - Behavioural Factors

Factor No. of SW's Prevalence of STD O.R. 95% CI x2 p value
No. %
<25 years 40 17 (42.5)        
>25 years 72 33 (45.8) 1.19 0.51-2.79 0.20 0.65
Illiterate 95 44 (46.3)        
Literate 23 12 (52.2) 1.26 0.46-3.46 0.25 0.61
H/o migration to other cities for sex work
Yes 43 18 (41.9)        
No 75 38 (50.7) 1.43 0.63-3.26 0.85 0.36
Age at first sexual intercourse
<20 years 90 43 (47.8)        
>20 years 28 13 (46.4) 1.06 0.42-2.69 0.02 0.90
Age at first professional sexual intercourse
<20 years 56 26 (46.4)        
>20 years 62 30 (48.4) 1.08 0.49-2.38 0.05 0.83
Partners per day
>5 36 15 (41.7)        
<5 82 41 (50.0) 1.4 0.59-3.36 0.70 0.40
Income per day (Rs.)
>100 52 24 (46.2)        
<100 66 32 (48.5) 1.1 0.50-2.43 0.06 0.8
Condom use
All the time 112 54 (48.2)        
Occasional/none 6 2 (33.3) 1.86 0.28-15.34 0.09+ 0.77
Past history of STD
Yes 70 37 (52.9)        
No 48 19 (39.6) 1.71 0.76-3.86 2.01 0.16
Treatment availed from
Doctors 28 13 (46.4)        
Others/none 90 43 (47.8) 1.06 0.42-2.69 0.02 0.91
* 6 had not given their age ; + Yates corrected value.

STI prevalence was higher in > 25 year age group, literate, not having history of travelling to other places for sex work, first sexual intercourse at less than 20 year age, having upto 5 sex partners per day, having income less than Rs. 100, having past history of STDs and no treatment taken/ treatment taking from unqualified persons. But this inter group difference was statistically not significant.


According to WHO report it is estimated that globally, in women aged 15-44 years, STIs, excluding HIV, were second only to maternal morbidity and mortality as a cause of healthy life lost. South and South East Asia with an estimated 150 million new cases in 1997 (45% of global new cases) is the major focus for STIs2. Studies in South Asia indicate extremely high prevalence rate of STIs in groups such as SWs8. Prevalence studies among them can give important insight into the picture at local level as well as the epidemiologically important factors.

There is a dearth of information regarding the epidemiology of STDs in India because of many reasons, such as recent recognition of STDs as a major public health problem, stigma and discrimination associated with the STDs, lack of inter departmental co-ordination for study, poor attendance of STD patients in the public clinics and academic institutions and availability of limited diagnostic facilities.

SWs are targeted in research because of various reasons such as : (1) they are considered core-group transmitters and there is concern to protect the wider public by breaking the cycle of transmission between them and their clients and (2) their HIV sero-positive rates are high enough to measure the effect of an intervention over a relatively short period of time and with manageable sample size9.

This study provides an opportunity to assess STD as well STI prevalence and certain epidemiological features of the same in a 'core' group. This study also provides a baseline data of STD and STI for planning of intervention and monitoring its impact.

There are approximately 600 SWs in RLA in Surat. Study area like RLA always face unexpected disturbances and the same ended up with registration of 124 SWs against projected sample size of 200. But amongst registered cases participation rate for clinical and laboratory based study was 95.2% in this survey. This rate is encouraging compared to reported participation rate of 19 to 86% in community based gynaecological morbidity studies in India10.

High prevalence of STIs (47.5%) suggests that every second SW was having one or more (from five) STIs. Particularly, high prevalence of Syphilis is this group is a matter of concern. 13 to 86% cases being asymptomatic for different infections impose limitations in syndromic management of STIs towards control.

STI rates among SWs decreased by more than 85% in 1994, from 25% in 1989 by Thailand's 100% condom programme11. In this study group, reported rate of all the time condom use with clients was 94% but about 41% of those having regular partners were not using it, which may be contributing to the high rate of STIs.

Though most SWs were aware about vaginal and penile discharge and genital sore as symptoms of STDs, there was a lack of knowledge about other symptoms of STDs. About 58% of them had history of suffering from one or other symptom of STDs in previous year, amongst which pain in lower abdomen, frequent painful urination and abnormal vaginal discharge were common.

The important point was that about 63% were either doing nothing or were indifferent towards the symptoms. Only one-fourth of them went to treatment providers. Poor health seeking behaviour of SWs was another important contribution to high rate of STIs. Over and Piot12 had estimated that cost per DALY saved by treating the classic STI was over US $50 in the non-core group and less than US$ 0.56 in the core group. They also observed that a policy of targeting the 'core' averts 10 times as many cases of STIs as would have been averted by a policy directed at the non-core group.

Socio-demographic profile of SWs showed that majority of them entered in this profession at very young age, were illiterate and were migrant from Nepal and Maharashtra. About one third of them travelled to other places mostly to Maharashtra, where STD and HIV prevalence is reported higher than in Surat14. Nine out of ten SWs were illiterate, which is a limiting factor in behaviour change process and empowerment of this group towards prevention of STDs.

In a study conducted amongst users of family planning clinic services in Tanzania various risk factors identified were age between 16-20 years, cohabiting, single, divorced, widow, having more than one partners in last three months etc14. While in Mwanza study done at antenatal centre, the risk factors identified were age less than 25 years, never used contraceptive, polygamous marriages, more than one partners in last three months etc., along with other symptoms.16

The sexual and reproductive history of SWs show that about 76% of them had their first sexual encounter before the age of 20 years and 83% of them had joined the profession before the age of 25 years. 90% of them were having more than three partners on an average per day. When we studied the association of socio-demographic and behavioural factors with prevalence of STIs, no significant association between STIs and the sociodemographic factors (socio-cultural determinants) and behavioural factors (practices) was observed in this study. This indicates that in such core group (SWs) the sex work itself appears to be major risk factor masking other confounders.

This study highlights that in the absence of epidemiologically higher risk factors in this study group, all of them should be considered higher risk group and a prevention strategy with blanket/mass coverage approach of intervention for STI treatment should be planned and tested.

Limitations of the Study

The participation of those having symptoms and expecting treatment and result may be higher leading to selection bias. The healthy workers effect can not be ruled out because of non-inclusion of the SWs who had already left the work due to ill health. Recall bias can not be ruled out in the history of symptoms/diseases.


This paper is an output from a project funded by Department for International Development UK. Family Health International (FHI), India, provided the technical assistance. We are grateful to DFID and FHI for providing financial and technical assistance, respectively. The views expressed in this paper are that of authors and does not necessarily reflect the views of FHI or DFID. The authors thank all the consultants, individuals and sex workers who had cooperated in this study.


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