Chlamydia:

A Disease

Without a

History

Michael Worboys

Chlamydia: Most commonly reported STI in UK

New diagnoses

0

20000

40000

60000

80000

100000

120000

140000

1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008

Ne

w c

as

es

Year

Incidence of STIs, 1998-2008

Syphilis (primary and secondary)

Gonorrhea (uncomplicated)

Chlamydia (uncomplicated)

Venereal Diseases

1860-1930 Venereal Disease/s – syphilis and gonorrhoea

1940s Syphilis, gonorrhoea and ‘Other conditions’

“balanoposthitis, lymphogranuloma venereum

(LGV), non-gonococcal urethritis (NGU),

thrush, trichomoniasis, ulcus actum vulvae,

vaginitis, vulvovaginitis, and warts.”

(McLachlan, 1944)

Venereal Diseases

Venereologists, 1940s

War – invalidism, tropics,

Special clinics

Bacteriologically- and Laboratory-oriented:

Wassermann Reaction

Salvarsan, Sulphonamides

Antibiotics

Venereal Diseases

1948 WHO Expert Committee on Venereal Diseases

First session, 12-16 January 1948

Venereal Diseases

1948 WHO Expert Committee on Venereal Diseases

First session, 12-16 January 1948

Venereal Diseases

1948 WHO Expert Committee on Venereal Diseases

1950 A.H. Harkness, Non-gonococcal urethritis: including the

genital manifestations of local and systemic diseases and

infestations of the urinary tract with protozoa, metazoa and

fungi.

1951 NGU first recorded, UK men only: 10,764 cases

( Cf. 14,975 gonorrhoea)

1965 NGU cases greater than gonorrhoea.

Venereal Diseases

NGU or Non-Specific Urethritis (NSU)

1960s Puzzle

Rising incidence – But treatable (sulphonamides and

tetracycline)

Unsatisfactory, residual category

Was its cause? inflammatory, or an infection.

? Trachoma-like agent (TRIC)

? Mycoplasma

? Trichomoniasis

? Fungi

? Haemophilus

? Virus

Venereal Diseases

NGU - NSU

1970s ‘In spite of much laboratory and other research, non-

specific genital infection continues to be the venereologist’s

most perplexing problem.’

Robbie Morton, 1975.

‘The Chlamydia genus is in fashion again’. Lancet, 1974

Cell culture of intracellular bacterium

Chlamydia ≈ 25-58% of NGU/NSU

Chlamydia in the Clinic

1980s NGU/NSU specific infections

Chlamydia, mycoplasma, LGV

Role in PID, Infertility

Culture service

HIV-AIDS STI clinics, specialism

Chlamydia co-factor in HIV/AIDS

Labs + New biotech companies

GUM, Gynaecology, STIs

Chlamydia in the Laboratory

C. trachomatis

Testing

Direct

‘Observe’ the organism

(culture/microscopy)

Proxy

Identify antibody

Identify antigen

Sensitivity? – Specificity?

http://www.chlamydiae.com/restricted/docs/labtests/diag_nucleicacidamplification.asp

‘Gold Standard’ II

now

‘Gold

Standard’

then

Chlamydia: A Disease without a History

NGU Chlamydia

NGU Chlamydia

NGU > Chlamydia

Chlamydia > NGU

New infection or newly recognised?

Increase? – ‘real’?

– more you look, more you find?