Estimating the tuberculosis burden in resource-limited countries: a capture-recapture study in Yemen.

BACKGROUND: The lack of applicable population-based methods to measure tuberculosis (TB) incidence rates directly at country level emphasises the global need to generate robust TB surveillance data to ascertain trends in disease burden and to assess the performance of TB control programmes in the context of the United Nations Millenium Development Goals and World Health Organization targets for TB control. OBJECTIVE: To estimate the incidence of TB cases (all forms) and sputum smear-positive disease, and the level of under-reporting of TB in Yemen in 2010. METHODS: Record-linkage and three-source capture-recapture analysis of data collected through active prospective longitudinal surveillance within the public and private non-National Tuberculosis Programme sector in twelve Yemeni governorates, selected by stratified cluster random sampling. RESULTS: For all TB cases, the estimated ratio of notified to incident cases and completeness of case ascertainment after record linkage, i.e., the ratio of detected to incident cases, was respectively 71% (95%CI 64-80) and 75% (95%CI 68-85). For sputum smear-positive TB cases, these ratios were respectively 67% (95%CI 58-75) and 76% (95%CI 66-84). CONCLUSION: We estimate that there were 13 082 (95%CI 11 610-14 513) TB cases in Yemen in 2010. Under-reporting of TB in Yemen is estimated at 29% (95%CI 20-36).

A case of renal infarction associated with elevated factor VIII level.

Elevated factor VIII level has recently been shown to be associated with increased risk of thrombosis. We report here a case of renal infarction in association with elevated factor VIII level. The patient presented with a three-day history of flank pain. Laboratory studies on presentation showed an elevated serum creatinine concentration and microscopic hematuria. He was found to have bilateral pulmonary emboli and left common femoral vein thrombosis; imaging studies showed evidence of renal arterial thrombosis with infarction. Hypercoagulability assessment showed an elevated factor VIII level. He was treated with heparin and warfarin with significant improvement in his renal function. Consideration should be given to measurement of factor VIII level as a part of the workup of unexplained thrombo-embolic events.

Patterns of injury in mycophenolate mofetil-related colitis.

Mycophenolate mofetil (MMF) was introduced as a new immune-suppression drug in the mid-1990s. It is widely utilized in solid-organ transplantation immune-suppression regimens. Side effects include gastrointestinal (GI) toxicity in the form of nausea, vomiting, and diarrhea. Physicians tend to reduce the dose of MMF or switch their patients to an enterio-coated formula to overcome the side effects. Because GI side effects are well linked to MMF, colonoscopy is not utilized in most of the cases to investigate the diarrhea. However, Crohn's disease-like changes in the colon, erosive enterocolitis, and graft versus host disease-like colonic changes associated with the use of MMF have been reported. Colonic findings in five patients whose symptoms resolved after substituting another agent for MMF are described in the present report. Repeat colonoscopy 4 months following discontinuation of MMF showed reparative changes in one of our patients. MMF is an important drug in organ transplantation immune-suppression regimens; however, with its widespread usage, additional side effects continue to be recognized.

The decline of tuberculosis in Yemen: evaluation based on two nationwide tuberculin surveys.

SETTING: Yemen. OBJECTIVE: To review the epidemiological situation of tuberculosis (TB) in Yemen by conducting a tuberculin survey and by comparing the results obtained with those of a previous tuberculin survey from 1991. DESIGN: A nationwide tuberculin survey enrolling 31,276 schoolchildren aged between 7 and 12 years. RESULTS: Skin indurations were recorded for 28,499 schoolchildren, of whom 16,927 (59.4%) had no bacille Calmette-Guérin (BCG) scar. Analysis of the distribution of indurations was difficult as it did not show any bimodal pattern. Prevalence of infection and annual risk of tuberculosis infection (ARTI) were thus estimated using the mirror image and mixture methods, and not the cut-off point method. The two methods indicated similar results: respectively 0.45% and 0.51% for prevalence of infection, and 0.05% and 0.05% for ARTI. In comparison with the 1991 tuberculin survey, the average annual decline of ARTI was 9.0% by the mirror method and 5.5% by the mixture method. CONCLUSION: Yemen seems to have a low ARTI (0.05%), and TB infection seems to be declining considerably. Analysis of the survey results highlighted the limitations of tuberculin surveys in countries with comparable epidemiological situations.

Nationwide survey on the prevalence of anti-tuberculosis drug resistance in the Republic of Yemen, 2004.

OBJECTIVES: To determine the prevalence of resistance to the four major anti-tuberculosis drugs, isoniazid, rifampicin, streptomycin and ethambutol, in Yemen. METHODS: Cluster sampling with probability proportionate to size was applied. Susceptibility to four major anti-tuberculosis drugs was examined. The proportion method using Löwenstein-Jensen medium or Ogawa medium was carried out. RESULTS: A total of 790 primary culture isolates from tuberculosis (TB) cases enrolled at the National Tuberculosis Institute, Yemen, were examined. In the confirmation culture at the supranational reference laboratory, 227 of them failed to grow on the secondary culture or were proved to be mycobacteria other than Mycobacterium tuberculosis and were excluded from further analysis. Among 563 cultures, 510 were obtained from new cases and 53 from previously treated cases. The prevalence of resistance to any four drugs was 9.8% (95%CI 7.0-12.5) among new cases and 17.4% (95%CI 12.0-33.5) among previously treated cases. The prevalence of multidrug-resistant TB was 3.0% (95%CI 1.5-4.5) among new cases and 9.4% (95%CI 0.2-18.7) among previously treated cases. CONCLUSION: The first nationwide prevalence survey on resistance to the four major anti-tuberculosis drugs in Yemen showed a relatively low prevalence of drug-resistant cases, but a high prevalence of multidrug resistance among new cases.

A survey on the referral of tuberculosis patients at the National Tuberculosis Institute, Yemen.

The study aims to determine whether the tuberculosis (TB) patients referred from the National Tuberculosis Institute (NTI), Sana'a City, actually present themselves, are registered and initiate treatment at the health facilities to which they are referred. In 2004, 591 smear-positive TB cases were diagnosed, 481 cases were referred back to health centres, 75 cases were registered at the NTI and 35 cases could not be retrieved. Among the 481 referred cases, 427 cases actually presented themselves and were registered at the health centres (88.8%). The average number of days between the day of referral and that of registration was 2.5 days (median 1 day).

Predictors of mortality in end-stage renal disease patients with mitral annulus calcification.

OBJECTIVE: Mitral annulus calcification (MAC) is an independent predictor of cardiovascular mortality in the general population. The purpose of the current historical cohort study is to assess risk factors for long-term mortality in end-stage renal disease (ESRD) patients with MAC (n = 30; age, 62 +/- 2 yr), as compared to ESRD patients without MAC (n = 30; age, 63 +/- 2 yr). Additional analysis compared ESRD patients with MAC to non-ESRD patients with MAC (n = 32; age, 66 +/- 2 yr). METHODS: The groups included age-matched male patients followed at a single center. Long-term survival was assessed by Kaplan-Meier analysis. Regular and stepwise Cox proportional hazards models were used to determine risk factors for mortality. RESULTS: There was a similarly high prevalence of cardiovascular complications, including hypertension, coronary artery disease, left ventricular hypertrophy, atrial fibrillation, and congestive heart failure, in all three groups. Median survival time was significantly longer in non-ESRD patients (90 months), compared with the ESRD with MAC (45 months) and ESRD without MAC (45 months) patients (log-rank test; P < 0.001). With stepwise Cox proportional hazards model, including ESRD patients with MAC and ESRD patients without MAC, increased calcium x phosphate product, decreased serum creatinine concentration, and the presence of coronary artery disease and lower extremity amputations were independent predictors of mortality for patients with ESRD. With stepwise Cox proportional hazards model, including ESRD patients with MAC and non-ESRD patients with MAC, the presence of ESRD, atrial fibrillation, diabetes, aortic valve calcification, coronary artery disease, and tricuspid regurgitation were independent predictors of mortality. CONCLUSION: The mortality rate was high in ESRD patients, approximately 15% per year. After accounting for baseline cardiovascular disease and traditional risk factors, the presence of MAC did not confer additional risk for mortality.