Genitourin Med 1985;61:261-3
Seroepidemiological survey of chlamydial genital
infections in Khartoum, Sudan
El-FADIL E OMER,* T FORSEY,t S DAROUGAR,t M H ALI,* AND
H A El-NAEEM§
From the *Department ofMedical Sciences, Um Al-Qura University, Makkah Al-Mukarramah, Sudan,
the tSubdepartment of Virology, Institute of Ophthalmology, University of London, London, the
*MedicalResearch Council, Khartoum, and the §Department ofObstetrics and Gynaecology, Faculty of
Medicine, Khartoum, Sudan
SUMMARY A total of 494 patients (90 men and 404 women) attending a sexually transmitted
diseases (STDs) clinic in Khartoum, Sudan, were-studied to assess the prevalence of chlamydial
genital infections. Antibodies to Chiamydia trachomatis serotypes D to K were found in four
(4' 4%) men and 42 (10- 4%) women, and 10 (2 5%) women had antibodies to serotypes A to C.
Studies in Khartoum have shown that gonorrhoea
affects almost 26% of men and 4% of women
patients attending a sexually transmitted disease
that non-gonococcal urethritis
(NGU) is the most common STD in men.' 2 The
prevalence of chlamydial genital infections
unknown, but studies from elsewhere in Africa have
suggested that they are as common there as in Europe
and the United States. In Ethiopia 32% of men and
45% of women patients with STD were found to
have been infected with Chlamydia trachomatis
genital serotypes.3 In Nigeria the rates were 19% in
men and 27% in women patients with STD.4
In this study we have attempted to assess the
prevalence of chlamydial genital infections by under-
taking a seroepidemiological survey of patients
attending an STD clinic in Khartoum, Sudan.
Patients and methods
We examined 494 consecutive patients attending an
STD clinic in Khartoum with various genitourinary
symptoms. Included were 90 men (aged 15 to 40),
most of whom presented with urethritis, and 404
women (aged 16 to 65), who mainly presented with
Address for reprints: Dr El-Fadil E Omer, Department of Medical
Sciences, Um Al-Qura University, Makkah Al-Mukarramah, Saudi
Accepted for publication 12 September 1984
We carried out laboratory tests to detect Neisseria
gonorrhoeae, Trichomonas vaginalis, and Candida
albicans, urine tests for defining urethritis, and the
Venereal Disease Research Laboratory (VDRL) test
to detect treponemal antibodies in Khartoum as
Whole blood taken by
discharge from men, and cervical discharge from
women were collected on cellulose sponges.5
Specimens were stored at 4°C and sent to the London
laboratory by post, where they were tested for the
presence of antichlamydial antibodies by a micro-
Serum was examined at starting dilutions of 1/16 for
anticllamydial IgG and. 1/8 for IgM. Genital
discharge was tested for specific antichlamydial IgG
and IgA at a starting dilution of 1/8.
test using pooled antigens.6
Table I shows the clinical and laboratory diagnoses
of STDs in all patients based on clinical signs and
laboratory tests carried out in Khartoum. Table II
shows that antibodies specific for C trachomatis
serotypes D to K were found in four (4 4%) of 90
men and 42 (10 4 4%) of 404 women. An additional 10
women had serum IgG antibodies to C trachomatis
serotypes A to C.
The titres of antibodies detected were generally
low. The four men who were seropositive had serum
IgG antibodies at a titre of 1/16. In the women the
although two women had titres of 1/128 and four
had titres of 1/256.
titre of serum IgG was
2 E Omer, T Forsev, S Darougar, M H Ali, and H A El-Naeeln
transmitted disease clinic in Khartoum
Diagnoses of patients attending a sexually
No (%) of
No (%) of
Trichomoniasis or candidiasis
Syphilis (VDRL test positive)
211 (52 2)
152 (37 6)
33 (36 7)
29 (32 2)
14 (15 6)
Of the 46 patients
detected, 38 (830Wo) were aged between 20 and 49,
most being between 20 and 29 years old. No patient
had antibodies specific
venereum (LGV) serotypes of C trachomatis or high
titres of broadly cross reactive antibodies, which
would have suggested
infection with LGV. No
antibodies to C psittaci types were detected in the
serum of any patient.
in whom antibodies were
trachomatis serotypes D to K in 494 patients attending an
STD clinic in Khartoum
Prevalence of antibodies
Source and type of
No (%) positive/No tested
Urethral IgG or IgA
Cervical IgG or IgA
42/404 (10 4)*
*Geometric mean of titres of serum IgG: men 1/16; women 1/26.
The prevalence of gonococcal infections was high in
men patients (36 7%) but much lower in women
(7 * 7%), as found in previous reports from Khartoum
(men 25-9%, women 3 80o).' 2 These findings may
reflect the social conditions prevailing in that city.
Although prostitution is technically illegal, Taha et al
noted that almost half the men presenting with an
STD had acquired their infection from prostitutes.'
gonorrhoea present for treatment this is not true of
the women and there must remain a reservoir of
population. Most (52-2%) of the women presenting
candidiasis and trichomoniasis.
The prevalence of infection with C trachomatis
serotypes D to K (genital pathogens7) was low in the
patients presenting with STDs in Khartoum (4 4% in
in the female
to be suffering from
men and 10 4% in women). These figures are much
lower than those found elsewhere in Africa;
Ethiopia the prevalence was 32% in men and 45% in
women,3 and in Nigeria the figures were 19% in men
and 27% in women.4 The titres of antichlamydial
antibodies detected in Sudanese patients were also
much lower than those found in other studies. The
geometric mean titre of serum IgG was 1/16 in men
and 1/26 in women in Khartoum compared with
1/138 and 1/193 in Ethiopia and 1/37 and 1/71 in
It is odd that there should be such a difference
the prevalence of gonococcal and
chlamydial infections in Khartoum, at least in men.
Elsewhere C trachomatis has been found as a con-
current infection in many patients with gonorrhoea.
It is possible that, in Khartoum, chlamydial infec-
tions are mild, and patients would therefore not have
a great incentive to attend a clinic for treatment.
Antibiotics are freely available in Khartoum, and self
medication may play a part in the low prevalence of
chlamydial infections and account for the low
antibody titres found.
Ten women in Khartoum had antibodies to C
trachomatis serotypes A
serotypes are usually associated with trachoma, they
can occasionally cause genital infections.8 Three of
the 10 women with these antibodies had gonorrhoea.
Trachoma is endemic in Sudan but is usually mild
and is not very common (Jones BR, personal com-
munication). The interaction of trachoma with
genital chlamydial infections in communities is not
known. A study in Iran, however, showed a low
prevalence of chlamydial genital infections (16/o) in
men patients with STD who lived in an urban area. In
surrounding rural areas, where trachoma is highly
no evidence of chlamydial
infections was found.9
The prevalence of clinical LGV also appeared to be
low in Khartoum. Only 3% of men had clinical signs
of this disease and in no patient (male or female)
were antibodies detected that suggested infection
with LGV agents.
Nearly 40% of women and 18% of men presenting
at the STD clinic in Khartoum had no apparent
infection, and 31 *7% of men patients had non-
gonococcal urethritis. Our results suggest that very
few of these patients were infected by chlamydiae,
leaving a large proportion of cases aetiologically
STD in Khartoum obviously poses a public health
problem that requires adequate control and manage-
will be interesting to observe whether
chlamydial infections assume greater importance in
as has been the case
to C. Although these
Seroepideiniological survey of chlamydial genital infections in Khartouml, Sludan
Taha OMA, Ali MH, Omer EE, Ahmed MA, Abbard SA.
Study of STDs in patients attending venereal disease clinics in
Khartoum, Sudan. British Journal of Venereal Diseases 1979;
Omer EE, Ali MH, Erwa H. Study of sexually transmitted
disease in Sudanese women. Trop Doct 1980; 10:99-102.
Forsey T, Darougar S, Dines RJ, Wright DJM, Friedmann PS.
Chlamydial genital infection in Addis Ababa, Ethiopia:
Diseases 1982; 58:370-3.
Darougar S, Forsey T, Osoba AO, Dines RJ, Adelusi B, Coker
Diseases 1982; 58:366-9.
Treharne JD, Darougar S, Simmons PD, Thin RN. Rapid
diagnosis of chlamydial infection of the cervix. British Journal
of Venereal Diseases 1978;54:403-8.
Treharne JD, Darougar S, Jones BR. Modification of the
diagnostic test for chlamydial infection. J Clin Pathol 1977; 30:
Dunlop EMC, Darougar S, Treharne JD. Epidemiology of
infection by serotypes D to K of Chlamydia trachoinatis.
British Journal of Venereal Diseases 1980; 56:163-8.
Jones BR. Prevention of blindness from trachoma. Trans
Ophthalmol Soc UK 1975; 95:16-33.
Darougar S, Jones BR, Cornell L, Treharne JD, Dwyer RStC,
Aramesh B. Chlamydial urethral infection in Teheran: a study
of male patients attending an STD clinic. British Journal of
Venereal Diseases 1982; 58:374-6.