Mass treatment with single-dose azithromycin for trachoma.
BACKGROUND
Trachoma, caused by repeated ocular infection with Chlamydia trachomatis, is an important cause of blindness. Current recommended dosing intervals for mass azithromycin treatment for trachoma are based on a mathematical model.


METHODS
We collected conjunctival swabs for quantitative polymerase-chain-reaction assay of C. trachomatis before and 2, 6, 12, 18, and 24 months after mass treatment with azithromycin in a Tanzanian community in which trachoma was endemic. For ethical reasons, at 6, 12, and 18 months, we gave tetracycline eye ointment to residents who had clinically active trachoma.


RESULTS
At baseline, 956 of 978 residents (97.8 percent) received either one oral dose of azithromycin or (if azithromycin was contraindicated) a course of tetracycline eye ointment. The prevalence of infection fell from 9.5 percent before mass treatment to 2.1 percent at 2 months and 0.1 percent at 24 months. The quantitative burden of ocular C. trachomatis infection in the community was 13.9 percent of the pretreatment level at 2 months and 0.8 percent at 24 months. At each time point after baseline, over 90 percent of the total community burden of C. trachomatis infection was found among subjects who had been positive the previous time they were tested.


CONCLUSIONS
The prevalence and intensity of infection fell dramatically and remained low for two years after treatment. One round of very-high-coverage mass treatment with azithromycin, perhaps aided by subsequent periodic use of tetracycline eye ointment for persons with active disease, can interrupt the transmission of ocular C. trachomatis infection.
Solomon
Anthony W
AW
Clinical Research Unit, London School of Hygiene and Tropical Medicine, London, United Kingdom. anthony.solomon@lshtm.ac.uk
Holland
Martin J
MJ
Alexander
Neal D E
ND
Massae
Patrick A
PA
Aguirre
Aura
A
Natividad-Sancho
Angels
A
Molina
Sandra
S
Safari
Salesia
S
Shao
John F
JF
Courtright
Paul
P
Peeling
Rosanna W
RW
West
Sheila K
SK
Bailey
Robin L
RL
Foster
Allen
A
Mabey
David C W
DC
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D019072:Antibiotic Prophylaxis; D017963:Azithromycin / Q000008:administration & dosage*; D002648:Child; D002675:Child, Preschool; D002692:Chlamydia trachomatis / Q000302:isolation & purification; D003228:Conjunctiva / Q000382:microbiology; D004334:Drug Administration Schedule; D019353:Endemic Diseases; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D009824:Ointments; D011247:Pregnancy; D015995:Prevalence; D013636:Tanzania / Q000453:epidemiology; D013752:Tetracycline / Q000008:administration & dosage; D014141:Trachoma / Q000188:drug therapy* / Q000453:epidemiology / Q000635:transmission
D000900:Anti-Bacterial Agents; D009824:Ointments; D017963:Azithromycin; D013752:Tetracycline