Download postal screening for genital Chlamydia trachomatis and prevalence

The prevalence of Chlamydia trachomtis infection
among women attending health clinics in ShirazIslamic Republic of Iran
Negin Hadi, MD MPH*, Fariba Barazandeh, MD**, Fariborz Azad, DVM***
*Associate professor of Community Medicine, Department of community
Medicine, Shiraz Medical School, Shiraz University of Medical Sciences, Shiraz ,
Islamic Republic of Iran
**General Physician, Shiraz Emergency Medical Services, Shiraz, Islamic Republic
of Iran
***Chief of Immunology Lab, Department of Pathology, Shiraz Medical School,
Shiraz, Islamic Republic of Iran
Correspondence Author: Dr. Negin Hadi, Associate professor of Community
Medicine, Department of community Medicine, Shiraz Medical School, Shiraz
University of Medical Sciences, Shiraz , Islamic Republic of Iran,
E-mail: [email protected]
1
Abstract
Introduction: Chlamydia trachomitis (C.T) is one of the most prevalent sexual
transmitted infections (STI) and micro-organisms detected in smears of
discharge in sexually active women. This population based study was under taken
for the first time in Shiraz (South of Iran) to determine the prevalence of genital
C.T in women. The infection usually has no symptoms; although it may have long
complications such as pelvic inflammatory disease, ectopic pregnancy, chronic
pelvic pain, tubal infertility and cervical cancer.
Methods : The number of 402 women, which referred to randomized selected
health centers in Shiraz, for routine pap smear screening test were tested using
IMAGEN Chlamydia test, a direct immunofluoresence test for detection of
Chlamydia in human urogenital specimen. The results of this test were compared
to socio-demographic condition of each participant as well as their STD symptoms
at present and in the past.
Results : The prevalence rate of Chlamydia infection was 8 %( 32/402). No
correlation was found between this infection and the age, marital age, number of
children, education and occupational status of the participants. On the other
hand, the correlation between the presence of infection and a positive history of
STD symptoms at present and in the past was significant.
Conclusion : Chlamydia infection is quite frequent in our society, where usually
the knowledge about STD infections is little. Considering the sequela of this
infection and the fact that this is a quiet disease, it seems rational to screen
sexually active women and inform them more about this issue.
Keywords: sexually transmitted infection – Chlamydia trachomatis – prevalence –
direct immunofluorensence – endocervical specimen – Iran
2
Introduction
Different microbial agents cause considerable morbidity and mortality
worldwide (1). Among these microorganisms, Chlamydia trachomatis infection
(CTI), an obligate intracellular bacterium, with millions of cases reported annually
throughout the world is the most common cause of bacterial sexually transmitted
infections (STI) with the highest incidence in developing countries, (2-3-4-5) which
could be transmitted in homosexuals even in women who have sex with women
(6). During the last decade the incidence rate of CTI has increased significantly in
Denmark, Norway, the United Kingdom and northern Ireland, Finland and
Sweden, also in eastern Europe(7). Amount of costs related to treatment of CTI
complications are estimated as the second grade after HIV (7).
Demographic risk factors for Chlamydia infection are young age, unmarried
status, and lower socioeconomic conditions. Other risk factors are anatomic
(ectopia), behavioral (number of sexual partners), microbiologic (concurrent
gonorrhea), and hormonal (use of oral contraception) (8).
Up to 70-80% of women infected with Chlamydia have no symptoms (2-4-9)
and up to 50% of infected men are asymptomatic (10). Some others are not easily
recognized with this infection on clinical grounds alone (8). However when left
untreated, this infection can lead to sequela complications such as pelvic
inflammatory disease, ectopic pregnancy, chronic pelvic pain and tubal scarring
and infertility (3-4-8-11). Most recent studies concluded that CTI may be a risk
factor of cervical cancer (7). Due to this, effective prevention efforts must include
screening programs to detect and treat asymptomatic infections (2). These
screening tests are designed to detect disease before clinical symptoms develop
and at the point when early intervention can improve long-term outcomes (5).
According to Cook Rl and Ostergaard L, young women who are sexually
active, are a perfect group for screening for genitourinary infections with C.
trachomatis as this infection with its sequela is common in this group especially
among females aged 15-19, early treatment will improve clinical outcomes and
screening tests are available (5-9).
3
Besides suggestive signs and symptoms and the presumptive
diagnosis(which is made in suspicious cases when gonococci are not found),
confirmatory tests are urethral, cervical or rectal cultures, urine or cervical NAAT(
nucleic acid amplification test), Polymerase chain reaction(PCR), Ligase chain
reaction(LCR), enzyme-linked immunosorbent assay(ELISA) and direct
immunofluoroscent antibody slide test (DFA)(12).
Based on the screening method used and the study group, the prevalence
rate would be different. A review of the articles between 2001 and 2008 shows
the prevalence of Chlamydia infection to be between 2% to 8.5% in normal
population referring for routine tests to health clinics all over the world (4-2).
In Iran the Chlamydia prevalence studies are mainly focusing on specific
groups such as those with PID, cervicitis, tubal infertility and pregnant women (313-14-15-16-17). In a study in 2007, Firoozjahi A., Bakhtiari A., showed a
prevalence rate of 11.6% for Chlamydia infection among women attending health
care centers in Babol(18).
The population based study about prevalence of CTI in women in Iran are
rarely performed, and it has not been studied in south of Iran. This peculiar
finding promoted the authors to investigate the prevalence of CTI and its risk
factors in general population women in Shiraz, which can be used for early
treatment and prevention of its sequela.
Methods
This is a cross sectional study carried out among women in fertility age
attending health care centers of Shiraz University of medical sciences. Shiraz city
(located in Fars province in western south of Iran) was divided into 3 areas of
north, middle and south and one health center was randomly selected from each
area. 402 women referred to these centers for routine Pap smear entered this
study.
4
A standardized questionnaire was made including socio-demographic
variables which were age, marital age, number of children, educational and
professional status and a series of questions asking about any STI symptoms at
the time of referral or before, and possible previous history of sexually
transmitted diseases.
Midwives of these 3 centers were educated for correct sampling, carrying
the samples and filling out the questionnaires.
IMAGEN Chlamydia test, a direct immunofluoresence test was used in this
study. It’s a qualitative test for detection of Chlamydia in human urogenital
specimen using a fluorescein labeled monoclonal antibody through fluorescein
isothiocyanide procedure (FITC).
For cervical sampling, this area was first cleansed to remove excess mucus,
blood, pus, etc. Then a cotton wool swab was entered in cervical canal and
approximately 1 centimeter. The swab was rotated several times at the
squamocolumnar epithelial junction and then withdrew without touching vaginal
surfaces. Then the swab was rolled on the microscope IMAGEN slide on a
specified area. It was left to be air dried at room temperature (15-30°c) and then
fixed in fresh acetone for 10 minutes and air dried again. The slides were
immediately carried in cold box to the laboratory to be froze and stored at -70°c
before staining.
The slides were then incubated with the FITC conjugated reagent for 15
minutes at 37°c in wet chamber. Excess reagent was removed by washing with
PBS(phosphate buffer saline) for 5 minutes. The stained areas were mounted and
viewed using the epifluorescein illuminative microscope.
The positive and negative laboratory results were then compared to the
information from the related questionnaires by means of SPSS version 16 using
Chi-Square and Fisher’s exact tests. The level of significance was considered as
P<0.05.
5
Results
The prevalence rate of Chlamydia infection was 8%(32/402) among the
participants.
89.6% of the women were housewives and 68.6% of them had at least
guidance school education. Other information about their occupational and
educational status is presented in table 2.
64.4% of women (260/402) had a positive history of symptoms of a sexual
transmitted disease in the past. There was a positive correlation between the
presence of these symptoms in the past and a positive result of IMAGEN test (Pvalue=0.001).
54.48% of the participants (219/402) were symptomatic for STD at the time
of referral. There was also a positive correlation between the presence of these
symptoms at present and a positive Chlamydia test result (P-value=0.001).
Table 3 and 4 shows the frequency of these symptoms in the past and
present time and their association with CT infection.
No significant correlation was found between the participants’ age, marital
age, child number, occupational and educational status and the result of
Chlamydia test. The frequency of positive results of Chlamydia test based on
these factors is presented in table 5.
Discussion
The prevalence rate of Chlamydia was 8% in this study which is comparable to the
results of another study done in Babol, Iran by Bakhtiari A., Firoozjahi A. in 2005
which showed Chlamydia infection in 11.6% of women attending health centers
(18).
6
Other similar studies show a prevalence rate of 2% to 8.5% (2-4-8-22). However
one should consider the difference between the test method used for screening
and the different groups studied based on their lifestyle in comparing the results
of different studies.
Although the test method of this study is highly specific, we found a less
prevalence rate in comparison to the results of the study by Bakhtiari, Firoozjahi
(2005). This difference is may be due to low sensitivity of direct fluorescence
assay in comparison to ELISA method used in the other study.
Chlamydia infection prevalence rate is mostly studied in specific groups for
example in those with cervicitis showing a prevalence rate of 12.5% to 20% (15-310). The prevalence rate has been 10.2% studied in a group with PID (9). These
rather higher prevalence among these groups compared with those attending
health clinics for routine checkups are expected as PID and cervicitis are among
the sequelae of Chlamydia infection.
Other studies among pregnant women have shown the prevalence rate of
Chlamydia infection to be 2 to 8% (17-21), almost the same as other studies done
on women without any special health condition (2-4-8).
According to the results of present study, the highest frequency of positive
CTI was in 26-35 age groups of women and reduced by increasing age. Although
the deference between age groups was statistically significance. Other studies
also had shown a decrease in infection chance with aging (4-8-18-19-20) and it is
declared clearly in Harrison’s principles of internal medicine that the peak
incidence of genital C. trachomatis is the late teens and early twenties (12). This
age related occurrence is possibly due to epithelial changes, partial immunity and
changing sexual behavior (18).We also expected to see higher rates of Chlamydia
infection in women with lower marital age.
In Iran extramarital sexual relationship is rare especially among women, so
the risk factor of having multiple partners, as showed to be important by other
studies (19) was not included in this study. Another study had showed that the
7
mean age at first intercourse is not significantly related to the risk of infection (1).
Our results also showed that the marital age does not affect the tendency to
infect by Chlamydia.
Child number, educational and economic status was considered as
determining factors of participants’ socioeconomic condition. Other studies had
shown that a poor socioeconomic condition would lead to a higher probability of
Chlamydia infection (4-18).We found more positive test results of CTI among
women with no child, those with high school education and self employees. It is
reported no significant differences in the prevalence of CTI among different
occupational groups (7).
45.5% and 35.3% of the cases were asymptomatic at present and in the
past respectively. Our result was different from the results of other studies which
have showed about 70% of Chlamydia infected women to be asymptomatic (2-49). However as we have not excluded those participants with other possible
sexual transmitted diseases, these result is expected as the symptoms would
belong to a coexist infection other than Chlamydia.
If symptomatic, Chlamydia infected cases are expected to have mild
symptoms of discharge, bleeding, lower abdominal pain or dysuria mostly (9).
Although most cases of Chlamydia would be asymptomatic, still it is expected to
see this infection more among symptomatic women (8). Vaginal discharge and
lower abdominal pain have been the most prevalent accompanying symptoms in
Chlamydia positive women in another study done over a group of pregnant
women (21). Also Firoozjahi A., Bakhtiari A.showed in their study that post coital
frequent bleeding and genital itching are the most frequent symptoms among
infected women (18). However according to our study, dysuria was the most
common symptom in the past and at present. The other prevalent symptoms at
present time were vaginal discharge and ulcer. This difference in presenting
symptoms can be due to possible coexisting STD infections.
We concluded, silent Chlamydia infection in general population of women,
is quite frequent in our society, where usually the knowledge about STD infections
8
is little. Considering the sequelae of this infection and the fact that this is a quiet
disease, it seems rational to screen sexually active women. Other randomized
trials also showed 50% reduction of incidence of pelvic inflammatory disease due
to CTI by used of systemic screening for genital CTI men and women with suitable
coverage as in United Kingdom this coverage is 37% (23).
We recommend more studies with lager sample size to perform screening
programs and promote general population knowledge about this issue .
9
References
1. Schlicht M.J., Lovrich S.D., Sartin J.S., et al. High prevalence of genital
mycoplasmas among sexually active young adults with uretritis or cervicitis
symptoms in La Crosse, Wisconsin. J. Clin. Microbiol. 2004; 42(10): 4636-40
2. Dicker L.W., Mosure D.J., Kay R.S., et al. An ongoing burden: chlamydial
infections among young American Indian women. Matern. Child Health J.
2008;12: S25-S29
3. Hashemi F.B., Pourakbari B., Zaeimi Yazdi J. Frequency of Chlamydia
trachomatis in women with cervicitis in Tehran, Iran. Infectious diseases in
obstetrics and gynecology. 2007
4. Hilger T.M., Smith E.M., Ault K. Predictors of Chlamydia infection among
women attending rural Midwest family planning clinics. Inf. Dis. Obst.
Gynecol. 2001; 9:3-8
5. Cook R.L., Ostergaard L. Current issues in screening for Chlamydia
trachomatis. Current infectious disease reports. 2003; 5:153-8
6. Bailey JV, Farquhar C, Owen C, Mangtani P. Sexually transmitted infections
in women who have sex with women. Sex Transm Infect. 2004
Jun;80(3):244-6.
7. Kucinskiene V, Sutaite I, Valiukeviciene S, Milasauskiene Z, Domeika M.
Prevalence and risk factors of genital Chlamydia trachomatis infection.
Medicina (Kaunas). 2006;42(11):885-94.
8. Einwalter L.A., Ritchie J.M., Ault K.A., et al. Gonorrhea and Chlamydia
infection among women visiting family planning clinics: racial variation in
prevalence and predictors. Perspectives on sexual and reproductive health.
2005; 37(3);135-140
9. Cates W., Wasserheit J.N. Genital chlamydial infections: epidemiology and
reproductive sequelae. Am. J. Obstet. Gynecol. 1991(June):1771-80
10. Weir E. Upsurge of genital Chlamydia trachomatis infection. CMAJ. 2004
Oct 12;171(8):855.
11. Malik A, Jain S, Hakim S, Shukla I, Rizvi M. Chlamydia trachomatis infection
& female infertility. Indian J Med Res. 2006 Jun;123(6):770-5.
10
12.Kasper, Braunwald, Fauci, et al. Harrison’s principles of internal medicine.
16th ed., McGraw-Hill, USA, 2005
13.Tabasi Z., Badami N., Atabakhshi M., et al. Evaluation of the prevalence of
Chlamydia trachomatis and its associated factors in patients with pelvic
inflammatory disorders in Shabihkhani hospital in Kashan in 2000. Kashan
University of medical sciences Fayz J. 1380; 5(18): 43-49
14. Eini E., Mirmiran P., Mohammadi Nasrabadi F., Velayi N. The relationship of
chlamyia trachomatis with symptomatic and asymptomatic cervicitis.
Iranian journal of infectous diseases and tropical medicine. 1380; 15(6):6472.
15-Amin M. Study of etiologic role of Chlamydia trachomatis in infertility,
Imam Khomaini clinic of infertility, Ahvaz, 1373. Scientific journal of
Kurdistan university of medical sciences. 1378; 11(3): 18-21
16- Esfandiari N., Gachkar L., Hamzehie K. Role of Chlamydia trachomatis in
tubal infertility. Pejouhandeh quarterly research journal. 1380;24(6):33-46
17- Behroozi R., Badami N. The prevalence of Chlamydia infection among
pregnant women refereed to perinatal clinics of Tehran university of
medical sciences in the year 1373. Journal of Mazandaran university of
medical sciences.1378;22-23(9):26-31
18- Firoozjahi A, Bakhtiari A. Chlamydia t rachomatis nfection in women
attending health centers in Babol: prevalence and risk factors. Eastern
Mediterranean Journal. 2007;13(5):1124-31
19- Levidiotou S., Vrioni G., Papadogeorgaki H., et al. Chlamydia trachomatis
infections in Greece: first prevalence study using nucleic acid amplification
tests. Springer-Verlag online. 2005(March)
20- Adams EJ, Charlett A, Edmunds WJ, Hughes G. Chlamydia trachomatis in
the United Kingdom: a systematic review and analysis of prevalence
studies. Sex Transm Infect. 2004 Oct;80(5):331-3.
21- Romoren M. Sundby J., Velauthapillai M. Chalmydia and Gonorrhoea in
pregnant Batswana women: time to discard the syndromic approach? BMC
Infectious Diseases. 2007; 7:27
11
22- Oliveira FA, Pfleger V, Lang K, et al. Sexually transmitted infections,
bacterial vaginosis, and candidiasis in women of reproductive age in rural
Northeast Brazil: a population-based study. Mem Inst Oswaldo Cruz. 2007
Sep;102(6):751-6.
23- Macleod J, Salisbury C, Low N, et al. Coverage and uptake of systematic
postal screening for genital Chlamydia trachomatis and prevalence of
infection in the United Kingdom general population: cross sectional study.
BMJ. 2005 Apr 23;330(7497):940. Epub 2005 Apr 4.
12
Table 1 shows the participants age, marital age and child number.
Table 1- Age, Marital age and child number of the participants
Age
Marital Age
Child Number
13
Minimum
Maximum
Mean
17
12
0
68
39
9
29.96
19.02
1.59
Standard
Deviation
7.33
4.07
1.27
Table 2- Occupational and educational status of the participants
Occupation
Unemployed
Self employee
Housewife
Total
Education
Illitrate
Primary school
Guidance school
High school
University degree
Total
14
Frequency
Percentage
34
8
360
8.4
2
89.6
402
100
12
75
138
138
39
3
18.7
34.3
34.3
9.7
402
100
Table 3- The frequency of STD symptoms in the past and their association with
CT infection
Frequency
NO.
Positive for CT infection
%
No.
%
Dysuria
121
46.5
19
15.7
Itching
168
64.6
21
12.5
Discharge
189
72.7
20
10.58
Ulcer
71
7.3
7
9.86
Herpetic lesion
1
0.38
0
0
Wart
1
0.38
1
100
15
Table 4- The frequency of STD symptoms at present and their association with
CT infection
Frequency
Positive for CT infection
NO.
Dysuria
53
%
24.2
No.
8
%
15.09
Itching
81
37
Discharge
159
72.6
22
13.8
Ulcer
79
36.1
11
13.9
Wart
1
0.46
1
100
16
8
9.9
Table 5 – The frequency of positive Chlamydia test based on participants
demographic factors
Frequency
Positive for CT infection
No.
%
Age
<25
122
9
7.38
26-35
196
18
9.18
36-45
70
5
7.14
>45
11
0
0
<20
235
20
8.51
20-25
137
9
6.56
26-35
24
1
4.17
>35
2
0
0
0
16
3
18.75
1-2
270
22
3-4
55
6
10.91
>5
13
0
0
Marital age
Child number
17
8.15
Occupation
Unemployed
34
1
2.9
Self employee
8
1
12.5
Housewife
360
30
8.3
87
5
5.7
Guidance school
138
10
7.2
High school
138
13
9.5
University degree
39
Education
Illitrate and
Primary school
18
3
7.7