As for yaws Chlamydial infections

The spectrum of clinically distinct diseases produced by infection with the different serotypes of Chlamydia trachomatis is summarized in Table 5.8. They include lymphogranuloma venereum (LGV -see p. 115), trachoma and inclusion conjunctivitis (TRIC) agents and also the strains involved in various genital tract infections. With the exception of lymphogranuloma venereum strains which have a predilection for lymph nodes, Chlamydia trachomatis only grows in the columnar epithelial cells found in the conjunctiva, cervix, urethra, the respiratory and gastrointestinal tracts and the rectal mucosa. This is reflected in the spectrum of diseases that Lli^V cause.

The members of this species are .ataral parasites of man only in contrast to the other species of chlamydia, Chi. psittacii, which is primarily a pathogen of birds, only occasionally infecting man.

Table 5.8: Serotypes and diseases of Chlamydia trachomatis

Dis.

Table 5.8: Serotypes and diseases of Chlamydia trachomatis

Dis.

A, B, C

Trachoma*

D-K

Inclusion conjunctivitis*

Non-gonococcal urethritis

Post-gonococcal urethritis

Epididymitis in adults

Proctitis

Cervicitis

Salpingitis

Perihepatitis

Inclusion conjunctivitis

Pneumonia in neonates

Otitis media

L1, L2, L3

Lymphogranuloma venereum*

♦Described in this chapter.

TRACHOMA

Occurrence:

Worldwide, uneven distribution,

mainly tropical and subtropical

Organism;

Chlamydia trachomatis (serotypes

A, B, C)

Reservoir:

Humans

Transmission:

Contact, fomites, mechanically by

flies

Control:

'SAFE' strategy: Surgery, Antibiotics,

Face Washing and Environmental

measures

Trachoma is a major cause of blindness in the tropics and is characterized by a mucopurulent discharge initially progressing to a chronic keratoconjunctivitis, with the formation of follicles, with hyperplasia, vascular invasion of the cornea and, in the late stage, gross scarring with deformity of the eyelids. Vision may be impaired, and in severe cases it may lead to blindness.

According to WHO's estimates, trachoma is responsible for at least 15% of the world's blindness, 6 million people irreversibly blinded by the disease and about 150 million active cases in need of treatment to prevent blindness.

The incubation period is from 4 to 12 days.

Bacteriology

The organism responsible for trachoma Chlamydia trachomatis is also termed the TRIC agent (trachoma inclusion conjunctivitis agent). It was first isolated with certainty in Peking and confirmed in the Gambia. Trachoma is caused by serotypes A, B and C.

Epidemiology

The occurrence of the infection is worldwide, including tropical, subtropical, temperate and cold climates, but the distribution of disease is uneven, being mostly in the Middle East, Mediterranean coast, parts of tropical Africa, Asia and South America (Plate 38). In the USA, it selectively affects certain groups such as American Indians and Mexican immigrants. It is estimated that throughout the world 300 million persons are infected with trachoma and 20 million are blind.

Reservoir and transmission

The reservoir of infection is in human beings. The common mode of transmission is mechanical from eye to eye by contaminated fingers, cloths, towels, bed clothes and flies (particularly Musca sor-bers). Infected nasal discharge and tears can also be agents of transmission. The more severe the infection the greater is the degree of virus shedding.

Was this article helpful?

0 0
The Complete Compendium Of Everything Related To Health And Wellness

The Complete Compendium Of Everything Related To Health And Wellness

A lot of us run through the day with so many responsibilities that we don't have even an instant to treat ourselves. Coping with deadlines at work, attending to the kids, replying to that demanding client we respond and react to the needs of other people. It's time to do a few merciful things to reward yourself and get your health in order.

Get My Free Ebook


Post a comment