Effect of a single mass antibiotic distribution on the prevalence of infectious trachoma

Context  The World Health Organization recommends mass antibiotic distributions in its strategy to eliminate blinding trachoma as a public health concern. Some hypothesize that a single distribution is sufficient to control the ocular strains of chlamydia that cause trachoma. Others believe infection will inevitably return and periodic treatments or other measures are essential. Objective  To determine whether ocular chlamydial infection returns to the community up to 24 months after a single mass antibiotic distribution in a hyperendemic region of Ethiopia. Design, Setting, and Participants  Longitudinal cohort study conducted March 2003 to March 2005 in the Gurage Zone of Ethiopia. Eight randomly selected villages were assessed for ocular chlamydial infection. Fifteen untreated villages were randomly chosen at 12 months to allow assessment of a secular trend. Intervention  A single dose of oral azithromycin was offered to all residents of the 8 selected villages who were aged 1 year or older. Main Outcome Measure  Prevalence of ocular chlamydial infection in all children aged 1 to 5 years from each intervention village prior to treatment and 2, 6, 12, 18, and 24 months after mass antibiotic treatment, and also in untreated villages enrolled at 12 months. Results  Five hundred fifteen children were examined for ocular chlamydial infection at baseline. For the follow-up examinations, the mean participation rate was 83%. The mean prevalence of infection in children aged 1 to 5 years decreased from 43.5% (95% confidence interval [CI], 35.0%-52.0%) to 5.1% (95% CI, 1.1%-9.2%) after treatment. On average, infection returned gradually over 24 months to 11.3% (95% CI, 4.5%-18.1%; P = .001). In 7 of 8 villages, infection was higher at 24 months than at 2 months. In the remaining village, no infection could be identified at any point after treatment. Villages enrolled at 12 months had significantly fewer infections than those enrolled 12 months earlier, suggesting a secular trend (P<.001). Conclusions  Ocular chlamydial infection was not eliminated in children aged 1 to 5 years after a single mass azithromycin distribution; it slowly returned over 24 months, although not to baseline levels. Repeated treatments or other effective measures will be necessary for elimination.      

Characteristics of trichiasis patients presenting for surgery in rural Ethiopia

AIMS: To determine the characteristics of trichiasis patients presenting for surgery in Wolayta Zone of Ethiopia. METHODS: Patients referred for trichiasis surgery by community health agents were evaluated by trained integrated eye care workers (IECWs) for the presence of trichiasis, locations of inturned lashes, severity of trichiasis, corneal opacity, and visual acuity. RESULTS: 1635 individuals with trichiasis presented for surgery. 82% had bilateral trichiasis; 91% of patients reported trichiasis duration of >2 years. Epilation was practised by over three fourths of the study subjects. A high proportion of patients tested positive for ocular Chlamydia trachomatis at presentation. 17% had monocular blindness and 8% were binocularly blind. Corneal opacity was highly associated with the trichiasis duration and severity and visual loss was associated with corneal opacity. CONCLUSION: Severe trichiasis reflects the magnitude of the trachoma problem in Ethiopia. Visual impairment due to trichiasis is highly associated with disease severity and duration. Early intervention to correct trichiasis before it become severe is recommended to prevent visual impairment.     

How reliable is the clinical exam in detecting ocular chlamydial infection?

PURPOSE: To describe the relationship between the clinical exam for trachoma and the polymerase chain reaction (PCR) for ocular chlamydia. METHODS: One hundred children in a trachoma-endemic area of Ethiopia were examined three times and swabbed twice for PCR analysis. The assays were compared, and an analysis of the variance between exam and PCR was performed. RESULTS: Inter-examiner agreement was 0.57 (Cohen's kappa), inter-PCR agreement 0.98, and agreement between examiner and PCR, 0.26-0.34. The positive predictive value of the exam in identifying infection was 66%. Inter-examiner variance accounted for 30% of the total variance between the exam and PCR, with the remainder presumably due to an underlying difference in what the exam and PCR measure. CONCLUSIONS: Despite modest inter-grader reliability and correlation with evidence of infection, the clinical exam is widely used due to its convenience and low cost. Efforts to make laboratory tests for ocular Chlamydia trachomatis more affordable would be useful.     

Audit of exracapsular cataract extraction with posterior chamber intraocular lens implantation in a tertiary eye care center in Ethiopia

A retrospective audit of records of 370 eyes of 315 patients for whom extracapsular cataract extraction with posterior chamber intraocular lens implantation (ECCE-PC IOL) was performed between 1998 and 1999 was made to determine postoperative visual outcome and complications. One hundred and ninety three patients were males and one hundred and seventy seven were females making a male to female ratio of 1:0.9. At two months postoperatively 82 (30.4%) of eyes had uncorrected visual acuity of 6/18 or better; while 176 (53.7%) of eyes attained an uncorrected visual acuity between 6/18 and 6/60, and 31 (11.5%) had visual acuity between 3/60 and 6/60. 340 of 358 (94.9%) had a preoperative visual acuity of < 3/60. As a result of the surgery, the percentage of blind eyes dropped from 94.9% to 4.4%. The commonest intra operative and early postoperative complications encountered were posterior capsular tear with vitreous loss (5.7%) and striate keratopathy (11.1%) respectively. Posterior capsular opacity was documented in 17 (4.6%) eyes as a late postoperative complication. Routine biometry, to calculate Intra ocular Lens (IOL) power was not done and this was the major limitation of the study. In conclusion, the study increases awareness of cataract surgery outcomes and provides a feedback to achieve better results both in terms of quality and quantity in cataract surgery. Further study with biometric measurement is recommended.     

L-NAME, nitric oxide and jejunal motility, blood flow and oxygen uptake in dogs.

1. The effects of the inhibitor of nitric oxide (NO) synthesis, NG-nitro-L-arginine methyl ester (L-NAME), on systemic arterial blood pressure and jejunal motility, blood flow, and oxygen uptake have been investigated in anaesthetized dogs. 2. L-NAME (cumulative doses of 0.1-20 mg kg-1, i.v.) dose-dependently increased blood pressure and jejunal motility and decreased heart rate. The maximal response of these three variables occurred at doses, 3, 10 and 10 mg kg-1, respectively. L-NAME (cumulative doses of 0.5-5 mg kg-1) also dose-dependently induced jejunal vasoconstriction. The jejunal vascular resistance returned to control values as the cumulative doses reached 10 and 20 mg kg-1, which corresponded to the maximal increase in jejunal motility. 3. A single intravenous injection of L-NAME (10 mg kg-1) produced a prompt increase in blood pressure, which lasted for at least 50 min. 4. L-NAME (10 mg kg-1) produced a progressive rise in jejunal motility reaching its maximum (47 +/- 6 mmHg) 15 min after the administration, and lasting for 40-50 min. Both the basal lumen pressure and the amplitude of rhythmic contractions increased during this period. 5. L-NAME (10 mg kg-1) produced a triphasic change in jejunal vascular resistance and blood flow measured by timed collection of venous outflow. The blood flow decreased initially (-43% at 5 min), increased (+35%) and returned to control value between 15 and 35 min, then decreased (-35%) 40-50 min post-infusion. Jejunal vascular resistance reflected the blood flow response (+88% at both 5 and 50 min).(ABSTRACT TRUNCATED AT 250 WORDS)     

Direct colorimetric assay for rapid detection of rifampin-resistant Mycobacterium tuberculosis

The colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay was standardized for direct detection of rifampin-resistant Mycobacterium tuberculosis in sputum samples. The sensitivity and specificity of the direct MTT assay matched those of the standard indirect susceptibility assay on 7H10 medium, and interpretable results were obtained for 98.5% of the samples within 2 weeks. Traditional methods of in vitro drug susceptibility testing are time consuming and laborious. Susceptibility tests on clinical isolates require 6 to 9 weeks, and tests conducted directly on smear-positive samples take about 3 weeks (International Union Against Tuberculosis and Lung Disease, The public health service national tuberculosis reference laboratory and the national laboratory network. Minimum requirements, role and operation in a low-income country, Paris, France, 1998, and P. T. Kent and G. P. Kubica, Public health mycobacteriology. A guide for the level III laboratory, Centers for Disease Control and Prevention, Atlanta, Ga., 1985). More-rapid methods are available but are very expensive for routine use under program conditions in countries with high levels of tuberculosis endemicity.