Indian J Sex Transm Dis Indian J Sex Transm Dis
Official Publication of the Indian Association for the Study of Sexually Transmitted Diseases
Indian J Sex Transm Dis
The Journal | Search | Ahead Of Print | Current Issue | Archives | Instructions | Subscribe | Login    Users online: 33   Home Email this page Print this page Bookmark this page Decrease font size Default font size Increase font size


 
  Table of Contents  
ORIGINAL ARTICLE
Year : 2010  |  Volume : 31  |  Issue : 2  |  Page : 104-108
 

Pattern of sexually transmitted infections and performance of syndromic management against etiological diagnosis in patients attending the sexually transmitted infection clinic of a tertiary care hospital


1 Department of Microbiology, UCMS & GTB Hospital, Dilshad Garden, Delhi, India
2 Department of Dermatology and STD, UCMS & GTB Hospital, Dilshad Garden, Delhi, India

Date of Web Publication7-Jan-2011

Correspondence Address:
Shilpee Choudhry
Department of Microbiology, UCMS & GTB Hospital, Dilshad Garden, Delhi - 110 095
India
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0253-7184.74998

Rights and Permissions

 

   Abstract 

Background and Objectives: The availability of baseline information on the epidemiology of sexually transmitted infections (STIs) and other associated risk behaviors is essential for designing, implementing, and monitoring successful targeted interventions. Also, continuous analysis of risk assessment and prevalence-based screening studies are necessary to evaluate and monitor the performance of syndromic management. The aim of the present study was to document the pattern of common STIs and to evaluate the performance of syndromic case management against their laboratory diagnoses. Materials and Methods: Three hundred consecutive patients who attended the STI clinic of a tertiary care hospital at Delhi, with one or more of the complaints as enunciated by WHO in its syndromic approach for the diagnosis of STIs, were included as subjects. Detailed history, demographical data, and clinical features were recorded and screened for common STIs by standard microbiological methods. Results: The mean age was 24 years and most of the male patients were promiscuous and had contact with commercial sex workers (CSWs 63.9%). Majority came with the complaint of genital discharge (63 males; 54 females) followed by genital ulcer (61 males; 30 females). Genital herpes accounted for the maximum number of STI (86/300) followed by syphilis (71/300). The sensitivity of genital discharge syndrome (GDS) was high for Neisseria gonorrhoeae and Chlamydia trachomatis (96% and 91%, respectively) while specificity was low (76% and 72%, respectively). The sensitivity of genital ulcer syndrome for herpes simplex virus-2 (HSV-2) and Treponema pallidum was 82.65% and 81.2%, respectively, while specificity reached 99% approximately. Conclusions: Viral STIs constitute the major burden of the STI clinic and enhance the susceptibility of an individual to acquire or transmit HIV through sexual contact. Syndromic algorithms have some shortcomings, and they need to be periodically reviewed and adapted to the epidemiological patterns of STI in a given setting.


Keywords: Genital discharge syndrome, genital ulcer syndrome, genital wart, HIV, sexually transmitted infection, syndromic approach


How to cite this article:
Choudhry S, Ramachandran V G, Das S, Bhattacharya S N, Mogha NS. Pattern of sexually transmitted infections and performance of syndromic management against etiological diagnosis in patients attending the sexually transmitted infection clinic of a tertiary care hospital. Indian J Sex Transm Dis 2010;31:104-8

How to cite this URL:
Choudhry S, Ramachandran V G, Das S, Bhattacharya S N, Mogha NS. Pattern of sexually transmitted infections and performance of syndromic management against etiological diagnosis in patients attending the sexually transmitted infection clinic of a tertiary care hospital. Indian J Sex Transm Dis [serial online] 2010 [cited 2019 Nov 13];31:104-8. Available from: http://www.ijstd.org/text.asp?2010/31/2/104/74998



   Introduction Top


Sexually transmitted infections (STIs), including human immunodeficiency virus (HIV), continue to present major health, social, and economic problems in the developing world, leading to considerable morbidity, mortality, and stigma. The prevalence rates apparently are far higher in developing countries where STI treatment is less accessible. [1]

Most of the STIs, both ulcerative and nonulcerative, are prevalent in India and constitute one of the major public health problems. Their profile varies with changes in socioeconomic, cultural, geographic, and environmental factors prevalent in different parts of the country. [2],[3],[4],[5],[6] However, due to lack of adequate laboratory infrastructure in the country, information regarding the profile of STIs relies essentially on syndromic diagnosis. Hence there is very limited data of laboratory-proven STIs. [7],[8] However, the availability of baseline information on the epidemiology of STIs and other associated risk behaviors remains essential for the designing, implementing, and monitoring successful targeted interventions. [9],[10]

The World Health Organization (WHO) has placed emphasis on syndromic approach for case measurement and management, particularly in high-prevalence areas having inadequate laboratory facilities, trained staff, and transport facilities. [11] Though the syndromically diagnosed STI has many limitations, continuous analysis of risk assessment and prevalence-based screening studies are necessary to evaluate and monitor the performance of syndromic management. [12]

The aim of the present study was to document the pattern of common STIs in patients attending the STI clinic of a tertiary care hospital, and to evaluate the performance of syndromic case management against their laboratory diagnoses.


   Materials and Methods Top


Three hundred consecutive patients from April 2007 to December 2008, who attended the STI clinic of a tertiary care hospital in Delhi, with one or more of the complaints as enunciated by WHO in its syndromic approach for the diagnosis of STI [13] were included as subjects. Followed up patients and asymptomatic patients were excluded from the study. Detailed history, demographical data, and clinical features were recorded from all the patients. All patients were managed on the basis of algorithms of the syndromic approach at the peripheral health center (PHC) level recommended by national AIDS control organization (NACO), India, after carrying out risk assessment. [14] All were screened for common STIs by standard microbiological methods. [15]

Urethral and endocervical swabs were collected from males and females, respectively, and subjected to direct examination by Gram staining and culture plate inoculation at the site of sample collection. A presumptive diagnosis of gonococcal infection was made on observing polymorphonuclear leucocytes (PMNLs) with Gram-negative intracellular diplococci (ICDC). If the smear showed five or more PMNLs in the absence of Gram-negative ICDC, a presumptive diagnosis of nongonococcal urethritis (NGU) was made in men. [16] For the isolation of  Neisseria More Details gonorrhoeae, swabs were directly inoculated on the chocolate agar plate containing vancomycin, colistin, and amphotericin-B and incubated in 5-10% carbon dioxide for 24-48 h. Isolates were identified as N. gonorrhoeae on the basis of colony morphology, Gram staining, oxidase test, and rapid carbohydrate utilization test (RCUT). [17]

Normal saline wet mount examinations were done to detect motile trophozoites of Trichomonas vaginalis and yeast cells for Candida infection. For the isolation of Candida, urethral/cervical discharge was inoculated on Sabouraud dextrose agar and identification was done by standard mycological techniques. [15]

A direct smear was made from the ulcer, if any, and subjected to direct examination by Gram staining and Leishman staining for the presence of multinucleated giant cells, shoals of fish bacilli, or safety pin-appearing bacilli to detect herpes simplex virus (HSV), Hemophilus ducreyi, and Calymmatobacterium granulomatis, respectively. [15]

Ten milliliters venous blood (without anticoagulant) was collected aseptically from all patients. Sera were separated and stored at −20°C in screw-capped glass tubes. HSV-2 IgM antibody in patients' sera was detected by the Ridascreen HSV-2 IgM (K5231, Germany) kit according to the manufacturer's instructions. It is an indirect enzyme immunoassay for the semiquantitative estimation of IgM antibodies against the HSV type-2 in human serum. HSV-1 IgM antibody was also detected by Meddens Diagnostics herpes simplex virus IgM μ capture EIA (REF 4051, The Netherlands). It is an antibody class capture immunosorbant assay for the detection of HSV IgM in human serum. Sera were also tested for antibodies of other STIs namely hepatitis B virus (HBV; 0003463 Hepalisa kit) and hepatitis C virus (HCV; third-generation HCV Microlisa kit, India) by ELISA and Treponema pallidum by Venereal Disease Research Laboratory (VDRL) test (an antigen from the serologist of Kolkata, Government of India) followed by the T. pallidum hemagglutination test (TPHA; Plasmatec TPHA test kit, Hansard Diagnostic, UK). Antigen detection for Chlamydia trachomatis in the genital swab of all the patients was performed by the Bio-Rad Chlamydia Microplate EIA (31189 United States) kit. All patients were tested for HIV by ELISA/rapid tests, using WHO-approved kits, following NACO guidelines, after pretest counseling and written informed consent, followed by post-test counseling.[18] Genital wart and molluscum contagiosum was detected clinically.

The proportions were calculated for various syndromes and disease prevalence. Sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) of various syndromes were calculated. Confidence intervals for STI prevalence were calculated for future monitoring.


   Results Top


Sociodemographic profile

The age of patients ranged from 15 to 53 years, the mean age being 24 years, and 62% of them were in the age group of 20-30 years. Sixty-four percent of the patients were male, and the male-to-female ratio was 2:1. Majority of the male patients (53.12%) were educated to the level of middle school while 50% of the females were illiterate. Sixty percent of the patients were married at the time of presentation and all but six of them were cohabiting with their spouse. Only 19% of them reported regular use of condom. Most of the patients (67%) had first sexual exposure between the ages of 19-25 years while 31% of the males and 22.22% of the females had first sexual contact at or before 18 years of age. Sixty-five percent of males had multiple sexual partners in the past 6 months and 63.9% had contact with commercial sex workers (CSWs). In contrast, most of the female patients (83.3%) had one sexual partner (husband in 80% of them).

Prevalence of sexually transmitted infection syndromes

Majority of the patients came with the complaints of discharge (63 males; 54 females) followed by genital ulcer (61 males; 30 females) as shown in [Table 1]. Twelve had multiple complaints.
Table 1: Incidence of syndrome/symptoms presented by sexually transmitted infections patients

Click here to view


Prevalence of laboratory-confirmed sexually transmitted infection

The prevalence of various STIs along with HIV, HBV, and HCV based on laboratory tests has been shown in [Table 2]. Genital herpes (IgM HSV-2) accounted for the maximum number of STI (86/300) followed by syphilis (71/300), genital wart (60/300), gonorrhea (58/300), and chlamydial infection (49/300). In all, 35% had more than one STI concomitantly at the time of presentation. The seroprevalence of HIV was 10.3%.
Table 2: Laboratory diagnosis, incidence of sexually transmitted infections pathogens

Click here to view


Performance of syndromic management against etiological diagnosis of sexually transmitted infection

[Table 3] shows the sensitivity, specificity, PPV, and NPV of syndromic management for symptomatic patients coming to the STI clinic. The sensitivity of genital discharge syndrome (GDS) to treat N. gonorrhoeae and C. trachomatis was 96.5% and 91.8%, respectively. However, the specificity was only 76.3% and 72.5%, respectively. Conversely, the specificity of GDS for the management of T. vaginalis, HSV-2, and Candida reached 99%, while the sensitivity was 50%, 5.9%, and 50%, respectively.
Table 3: Performance of syndromic management

Click here to view


The sensitivity of genital ulcer syndrome for HSV-2 and T. pallidum was 82.65% and 81.2%, respectively, while specificity reached to 99% approximately.

The PPV of syndromic management ranged from 75% to 95%, except GDS for N. gonorrhoeae, C. trachomatis, and HSV-2 where it was 49%, 39%, and 50%, respectively. However, NPV ranges from 94% to 98.9% except GDS for C. trachomatis (72.5%).


   Discussion Top


There is a dearth of information regarding the epidemiology of STIs in India for many reasons such as stigma and discrimination associated with the STI, lack of interdepartmental coordination for studies, poor attendance of STI patients at the public clinics and academic institutions, and availability of limited diagnostic facilities. This in-depth analysis offers an important insight into the burden and pattern of various STIs and on the performance of syndromic management of STIs in comparison with laboratory diagnosis.

In our study, the peak age group of patients ranges from 20 to 30 years (62%), and vast majority of them were male (64%), thus constituting the major bulk of the STI patients. Also, majority of the male patients had promiscuous behavior as 66% of males had more than three sexual partners and 63.9% had contact with CSWs, suggesting that professional prostitution still remains the main source of STI among men having promiscuous behavior.

In our study, GDS was reported in 39% of patients and GUS in 30% while multiple symptoms were seen in 12% of patients. This is a matter of concern in the context of HIV transmission as genital ulcer facilitates the transmission of and enhances susceptibility to HIV infection by sexual contact [19],[20] while nonulcerative STIs like gonorrhea and chlamydia increase shedding of the HIV virus in the genital tract by recruiting HIV-infected inflammatory cells as part of normal host response. [19],[21]

In the present study, HSV-2 (28.7%) was the commonest infection followed by syphilis (23.7%), wart (20%), gonorrhea (19.3%), chlamydia (16.3%), HIV (10.3%), HBV (6%), T. vaginalis (4.7%), M. contagiosum (4.7%), Candida (2%), and HCV (1%). A marked decline in bacterial STIs, resulting in an apparent increase in viral STIs, has been reported from different regions of India. [7],[8],[22] Our study confirmed a similar pattern of higher incidence of viral STIs which could be due to the increased usage of antibiotics. Also, a high incidence of HIV seropositivity (10.3%) in the study population indicates the close association of STI with HIV and the importance of early diagnosis of these curable diseases. Previous studies from different parts of the country have also supported these observations. [22]

Algorithms based on a syndromic approach were evaluated in many different settings. [23],[24] In our study, the sensitivity of the syndromic approach for the treatment of N. gonorrhoeae and C. trachomatis was 91.83% and 96.5%, respectively, which was fairly high indicating that large number of those presented with GDS related to gonorrhea and chlamydia were effectively treated. However, their low specificity (72-76%) indicates that many individuals were falsely diagnosed and treated as positive. This overdiagnosis and overtreatment expose more patients to unnecessary antibiotics which could result in the emergence of antimicrobial resistance. For example, over the past decade, strains of N. gonorrhoeae have been reported to develop high levels of resistance against several antimicrobial agents, previously used for the treatment of gonorrhea. [25] Indian studies have also reported an increase in the spectrum and level of antibiotic resistance of N. gonorrhoeae isolates in the recent year compared to that seen previously. [26]

The present study showed low sensitivity of GDS in detecting T.vaginalis (50%), HSV-2 (5.9%), and Candida (50%) suggesting that syndromic management for patients with GDS related to these pathogens will not be very useful.

The algorithm used for GUD tries to identify the presence of herpes, syphilis and/or chancroid. [14] In our study population, the sensitivity of GUS for herpes and syphilis was 82.6% and 82.1%, respectively, while the specificity was 98.7% and 99.7%, respectively, suggesting that syndromic management for GUD is not much effective in identifying herpes and syphilis. Various studies have been done to validate diagnostic algorithm for GUS. In a study conducted in China, [27] when syndromic management was used, all patients with syphilis had been correctly treated yielding 100% sensitivity but a large proportion of nonsyphilitic patients were overtreated yielding 5% specificity. In contrast, in a study conducted in the red light area of Surat, India, syndromic management for syphilis yielded 14.8% sensitivity and 96.7% specificity. [28]

In conclusion, viral STIs constitute the major burden of the STI clinic and enhance the susceptibility of an individual to acquire or transmit HIV through sexual contact. Though the syndromic approach has been a major step forward in rationalizing and improving the management of STIs, but syndromic algorithms have some shortcomings, and they need to be periodically reviewed and adapted to the epidemiological patterns of STIs in a given setting.

 
   References Top

1.Chin J. Public health surveillance of AIDS and HIV infections. Bull World Health Organ 1990;68:529-36.   Back to cited text no. 1
[PUBMED]  [FULLTEXT]  
2.Thapa DM, Singh S, Singh A. HIV infection and sexually transmitted diseases in a referral STD Centre in South India. Sex Transm Infect 1999;75:191-3.  Back to cited text no. 2
    
3.Khanna N, Pandhi RK, Lakhn Pal S. Changing trends in sexually transmitted diseases in Chandigarh. Indian J Sex Transm Dis 1996;17:79-81.  Back to cited text no. 3
    
4.Bajaj JK, Kulkarni JD, Damle AS, Patwardhan NS, Karyakarte RP, Deshmukh AB. HIV seropositivity in STD patients. Indian J Med Microbiol 2000;18:44.  Back to cited text no. 4
    
5.Khandpur S, Agarwal S, Kumar S, Sharma VK, Reddy BS. Clinico-epidemiological profile and HIV seropositivity of STD patients. Indian J Sex Transm Dis 2001;22:62-5.  Back to cited text no. 5
    
6.Bairy I, Balachandran C, Shivananda PG. HIV seropositivity in STD clinic attendants. Indian J Sex Transm Dis 2001;22:6-9.  Back to cited text no. 6
    
7.Narayanan B. A retrospective study of the pattern of sexually transmitted diseases during a ten year period. Indian J Dermatol Venereol Leprol 2005;71:333-7.  Back to cited text no. 7
[PUBMED]  Medknow Journal  
8.Kumar B, Sahoo B, Gupta S, Jain R. Rising incidence of genital herpes over two decades in a sexually transmitted disease clinic in north India. Int J STD AIDS 2002;13:115-8.  Back to cited text no. 8
    
9.Risbud A. Human immunodeficiency virus (HIV) and sexually transmitted diseases (STDs). Indian J Med Res 2005;121:369-76.  Back to cited text no. 9
    
10.World Health Organization. A new approach to STD control and AIDS prevention. Glob AIDSnews 1994;4:13-5.  Back to cited text no. 10
    
11.UNAIDS/WHO. Sexually transmitted diseases: Policies and principles for prevention and care. Geneva: UNAIDS, UNAIDS/01.11E; 1999  Back to cited text no. 11
    
12.Dallabetta GA, Gerbase AC, Holmes KK. Problems, solutions and challenges in syndromic management of sexually transmitted diseases. Sex Transm Infect 1998;74:S1-11.  Back to cited text no. 12
[PUBMED]    
13.World Health Organization. Management of patients with sexually transmitted diseases. WHO Technical Report Series No. 810. Geneva: World Health Organization; 1991  Back to cited text no. 13
    
14.National AIDS Control Organisation. Simplified STI and RTI treatment guidelines. New Delhi: NACO, Ministry of Health and Family Welfare, Government of India; 1998.  Back to cited text no. 14
    
15.Collee TG, Duguid JP, Fraser AG, Marmion BP, editors. Mackie and Mc Cartney Practical Medical Microbiology 14 th ed. New York: Churchill Livingstone; 1989.  Back to cited text no. 15
    
16.Bowie WR. Comparison of gram stain and first voided urine sediment in the diagnosis of urethritis. Sex Transm Dis 1978;5:39-42.  Back to cited text no. 16
[PUBMED]    
17.WHO. Laboratory diagnosis of gonorrhoea. South-East Asia, New Delhi, India: WHO Regional Publication: 1999.   Back to cited text no. 17
    
18.HIV Testing Manual, Laboratory Diagnosis, Biosafety and Quality Control, National Institute of Communicable Diseases, Delhi and National AIDS Control Organisation, Ministry of Health and Family Welfare, Government of India, New Delhi; 2000.  Back to cited text no. 18
    
19.Sulak PJ. Sexually transmitted diseases. Semin Reprod Med 2003;21:399-413.  Back to cited text no. 19
[PUBMED]  [FULLTEXT]  
20.Wald A, Corey L. How does herpes simplex virus type 2 influence human immunodeficiency virus infection and pathogenesis? J Infect Dis 2003;187:1509-12.  Back to cited text no. 20
[PUBMED]  [FULLTEXT]  
21.Jaitley NK, Pathak K, Saojii AM. Bacteriological study of gonococcal and NGV with specific reference to CT. Indian J Sex Transm Dis 1993;14:15-7.  Back to cited text no. 21
    
22.Ray K, Bala M, Gupta SM, Khunger N, Puri P, Muralidhar S, et al. Changing trends in sexually transmitted infections at a Regional STD Centre in north India. Indian J Med Res 2006;124:559-68.  Back to cited text no. 22
    
23.Pettifor A, Walsh J, Wilkins V, Raghunathan P. How effective is syndromic management of STDs? A review of current studies. Sex Transm Dis 2000;27:371-85.  Back to cited text no. 23
[PUBMED]  [FULLTEXT]  
24.Ray K, Muralidhar S, Bala M, Kumari M, Salhan S, Gupta SM, et al. Comparative study of syndromic and etiological diagnosis of reproductive tract infections/sexually transmitted infections in women in Delhi. Int J Infect Dis 2009;13:352-9.  Back to cited text no. 24
    
25.DeSchryver A, Meheus A. Epidemiology of sexually transmitted diseases: The global picture. Bull World Health Organ 1990;68:639-54.  Back to cited text no. 25
    
26.Bala M, Ray K, Kumari S. Alarming increase in ciprofloxacin and penicillin resistant Neisseria gonorrhoeae isolates in New Delhi, India. Sex Transm Dis 2003;30:523-5.  Back to cited text no. 26
[PUBMED]  [FULLTEXT]  
27.Liu H, Jamison D, Li X, Erjian MA, Yin Y, Detels R. Is syndromic management better than the current approach for treatment of STDs in China? Sex Transm Dis 2003;30:327-30.  Back to cited text no. 27
    
28.Desai VK, Kosambiya JK, Thakor HG, Umrigar DD, Khandwala BR, Bhuyan KK. Prevalence of sexually transmitted infections and performance of STI syndromes against aetiological diagnosis, in female sex workers of red light area in Surat, India. Sex Transm Infect 2003;79:111-5.  Back to cited text no. 28
[PUBMED]  [FULLTEXT]  



 
 
    Tables

  [Table 1], [Table 2], [Table 3]


This article has been cited by
1 Diagnosis ofNeisseria gonorrhoeaeUsing Molecular Beacon
Divya Sachdev,Achchhe Lal Patel,Subash Chandra Sonkar,Indu Kumari,Daman Saluja
BioMed Research International. 2015; 2015: 1
[Pubmed] | [DOI]
2 Prevalence of Trichomoniasis, Vaginal Candidiasis, Genital Herpes, Chlamydiasis, and Actinomycosis among Urban and Rural Women of Haryana, India
Brij Bala Arora,Megha Maheshwari,Naiya Devgan,D. R. Arora
Journal of Sexually Transmitted Diseases. 2014; 2014: 1
[Pubmed] | [DOI]
3 Proof of concept: A bioinformatic and serological screening method for identifying new peptide antigens for Chlamydia trachomatis related sequelae in women
Scott H. Stansfield,Pooja Patel,Joseph Debattista,Charles W. Armitage,Kelly Cunningham,Peter Timms,John Allan,Aruna Mittal,Wilhelmina M. Huston
Results in Immunology. 2013; 3: 33
[Pubmed] | [DOI]
4 Proof of concept: A bioinformatic and serological screening method for identifying new peptide antigens for Chlamydia trachomatis related sequelae in women
Stansfield, S.H. and Patel, P. and Debattista, J. and Armitage, C.W. and Cunningham, K. and Timms, P. and Allan, J. and Mittal, A. and Huston, W.M.
Results in Immunology. 2013; 3: 33-39
[Pubmed]
5 Prevalence of HIV among attendees of ARFH Centre in Ibadan, Southwestern Nigeria
Okonko, I.O. and Okerentugba, P.O. and Akinpelu, A.O.
Middle East Journal of Scientific Research. 2012; 11(1): 7-12
[Pubmed]
6 Prevalence of sexually transmitted infections (STIs) among attendees of AFRH Centre in Ibadan, Southwestern Nigeria
Okonko, I.O. and Akinpelu, A.O. and Okerentugba, P.O.
Middle East Journal of Scientific Research. 2012; 11(1): 24-31
[Pubmed]
7 Prevalence of sexually transmitted infections in a tertiary care centre
Karn, D., Amatya, A., Aryal, E.R., Kc, S., Timalsina, M.
Kathmandu University Medical Journal. 2011; 9(34): 44-48
[Pubmed]
8 Clinico-epidemiological study of sexually transmitted infections in males at a rural-based tertiary care center
Vora, R., Anjaneyan, G., Doctor, C., Gupta, R.
Indian Journal of Sexually Transmitted Diseases. 2011; 32(2): 86-89
[Pubmed]



 

Top
Print this article  Email this article
 

    

 
  Search
 
  
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Article in PDF (426 KB)
    Citation Manager
    Access Statistics
    Reader Comments
    Email Alert *
    Add to My List *
* Registration required (free)  


    Abstract
    Introduction
    Materials and Me...
    Results
    Discussion
    References
    Article Tables

 Article Access Statistics
    Viewed5347    
    Printed248    
    Emailed2    
    PDF Downloaded346    
    Comments [Add]    
    Cited by others 8    

Recommend this journal