An office building outbreak: the changing epidemiology of tuberculosis in Shenzhen, China.

Tuberculosis (TB) is generally considered a disease that principally afflicts the low-income segments of a population. In the Nanshan District of Shenzhen, China, with the economic transformation and a new Headquarters Economy (HE) emerging, there are now more cases in office workers than in manufacturing workers. To illustrate this trend, we describe a small TB outbreak in an office building located in the centre of the rapidly growing HE district. Two active pulmonary tuberculosis cases were found in workers who shared an office, and whole genome sequencing showed that the genetic distance between the strains of the two cases was just one single nucleotide polymorphism, consistent with intra-office transmission. Investigation of 30 other workers in the same or adjacent offices with interviews, interferon-gamma release assays (IGRAs) and chest X-rays, identified one new TB case and latent tuberculosis infection (LTBI) in 40.0% (12/30) of the contacts. The offices were under-ventilated. None of the IGRA positive, asymptomatic contacts agreed to receive treatment for LTBI, presumably due to TB stigma, and over the next 2 years 69.0% (20/29) of the contacts were lost to follow-up. Treatment for LTBI and stigma of TB remain challenges here. Office workers in the HE of rapidly economic developing areas should be targeted with increased vigilance by TB control programmes.

Antimycobacterial and PknB Inhibitory Activities of Venezuelan Medicinal Plants.

Global control and elimination of tuberculosis are hindered by the high prevalence of drug-resistant strains, making the development of new drugs to fight tuberculosis a public health priority. In this study, we evaluated 118 extracts from 58 Venezuelan plant species for their ability to inhibit the growth of Mycobacterium tuberculosis mc26020, using the agar dilution method. Additionally, we determined the ability of these extracts to inhibit the activity of PknB protein, an essential M. tuberculosis serine/threonine kinase, using a high-throughput luminescent assay. Of the 118 extracts tested, 14 inhibited bacterial growth with a minimum inhibitory concentration ≤500 µg/ml, and 36 inhibited the kinase activity with a half-maximal inhibitory concentration <200 µg/ml. Five extracts inhibited M. tuberculosis growth and inhibited the activity of the kinase protein, suggesting that this could be the basis of their growth inhibition.

Tuberculosis trends in a hot-spot region in Paris, France.

SETTING: Tuberculosis (TB) incidence is declining overall in France, but not in Paris where some areas remain relative hot spots for TB.OBJECTIVES: To obtain a better knowledge of local TB epidemiology in order to facilitate control measures.DESIGN: Analysis of demographic data of TB patients diagnosed at the Bichat-Claude Bernard Hospital from 2007 to 2016, with spoligotyping of Mycobacterium tuberculosis complex isolates.RESULTS: During the study period, 1096 TB patients were analysed. The incidence of TB diagnosis was stable, averaging 115 patients per year, predominantly males (71%), foreign-born (81%), with pulmonary TB (77%) and negative HIV serology (88%). The mean age of foreign-born TB patients decreased over the study period, most significantly in recent arrivals in France, whose average age decreased by two years (P = 0.001). The time period between arrival in France and being diagnosed with active TB decreased annually significantly by 0.75 years (P = 0.02). The proportion of L4.6.2/Cameroon and L2/Beijing sub-lineages increased annually by 0.7% (P < 0.05). Multi-drug resistant strains, representing 4% of all strains, increased annually by 0.75% (P = 0.03)CONCLUSION: The number of TB patients remained high in northern Paris and the surrounding suburbs, suggesting the need for increased control measures.

Detection and characterization of waterborne gastroenteritis viruses in urban sewage and sewage-polluted river waters in Caracas, Venezuela.

The detection and molecular characterization of pathogenic human viruses in urban sewage have been used extensively to derive information on circulating viruses in given populations throughout the world. In this study, a similar approach was applied to provide an overview of the epidemiology of waterborne gastroenteritis viruses circulating in urban areas of Caracas, the capital city of Venezuela in South America. Dry season sampling was conducted in sewers and in a major river severely polluted with urban sewage discharges. Nested PCR was used for detection of human adenoviruses (HAds), while reverse transcription plus nested or seminested PCR was used for detection of enteroviruses (HuEVs), rotaviruses (HRVs), noroviruses (HuNoVs), and astroviruses (HAstVs). HRVs were fully characterized with genotype-specific primers for VP4 (genotype P), VP7 (genotype G), and the rotavirus nonstructural protein 4 (NSP4). HuNoVs and HAstVs were characterized by sequencing and phylogenetic analysis. The detection rates of all viruses were >or=50%, and all sampling events were positive for at least one of the pathogenic viruses studied. The predominant HRV types found were G1, P[8], P[4], and NSP4A and -B. Genogroup II of HuNoVs and HAstV type 8 were frequently detected in sewage and sewage-polluted river waters. This study reveals relevant epidemiological data on the distribution and persistence of human pathogenic viruses in sewage-polluted waters and addresses the potential health risks associated with transmission of these viruses through water-related environmental routes.

A randomised controlled trial of stepwise sputum collection to increase yields of confirmed tuberculosis.

The proportion of bacteriologically confirmed tuberculosis (TB) in China has decreased far below the worldwide average. To investigate whether stepwise measures to ensure sputum quality can improve the rate of bacteriologically confirmed TB. We enrolled 980 adults with suspected TB from three counties in China during 2017 for this multicentre randomised controlled trial. Half the participants (n = 490) were randomly assigned to intervention groups that received instructions by a study nurse, and sputum induction, if necessary. In the remaining 490 patients, sputum samples were collected without observation. The primary outcome was the proportion of patients detected as bacteriologically positive on smear, culture or molecular assays (EasyNAT or Xpert). Bacteriological confirmation rates were significantly higher in the intervention than in the control group: overall (159/490 [32%] vs. 122/490 [25%]; P = 0.009); confirmation using smear (17% vs. 11%; P = 0.010); confirmation using culture (28% vs. 21%; P = 0.021); and confirmation using molecular assays (27% vs. 18%; P = 0.001). Most of the improvement was in patients who received instruction alone, while improvement was greatest in younger patients (adjusted odds ratio 1.27, 95%CI 1.05-1.53 per 10 years). If implemented effectively in resource-limited primary care clinics, our simple stepwise procedure combining instruction and sputum induction could increase the proportion of bacteriologically confirmed TB significantly. .

Comparison of redox and D29 phage methods for detection of isoniazid and rifampicin resistance in Mycobacterium tuberculosis.

Rapid, accurate and inexpensive methods are essential to detect drug-resistant Mycobacterium tuberculosis and allow timely application of effective treatment and precautions to prevent transmission. The proportion method, the MTT and Alamar Blue redox methods, and the D29 mycobacteriophage assay, were compared for their ability to detect resistance to isoniazid and rifampicin. When tested against a panel of known M. tuberculosis strains, the redox methods and the D29 assay showed good sensitivity and specificity compared to the proportion method, suggesting that they could be useful alternatives for identifying multidrug resistance in M. tuberculosis.

Pyrazinamide resistance in Mycobacterium tuberculosis arises after rifampicin and fluoroquinolone resistance.

BACKGROUND: Multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis (TB) constitute a major public health concern. OBJECTIVE: To determine the timing of pncA mutations that confer pyrazinamide (PZA) resistance in relation to mutations conferring resistance to isoniazid (INH) and rifampicin (RMP). DESIGN: Isolates from two major urban centres--Paris (101 strains) and Shanghai (171 strains)--were investigated for the association of pncA mutations with resistance to drugs other than PZA. RESULTS: The proportion of pncA mutations found in INH-monoresistant strains was not increased. CONCLUSION: pncA mutations associated with PZA resistance were found almost exclusively in MDR-TB strains, underlining the importance of determining PZA resistance when treating MDR- or XDR-TB.

Examination of the clonal deletion hypothesis following transfusions in rat cardiac transplants.

To test the clonal deletion hypothesis, different levels of immunization were carried out by 0, 1, 2, or 3 transfusions preoperatively, together with 10 methods of immunosuppression. In this way, it was hoped that we could determine the optimal way to immunize and the optimal immunosuppressant treatment to deactivate the responding cells. With the Buffalo-to-Lewis rat heart allograft model, the control mean survival rate was 7 days. Rats with 2 or 3 transfusions had 5- and 12-day survival rates, respectively. If azathioprine was given in addition before grafting, 19- and 18-day survival rates were seen, and if azathioprine was given after grafting, extended survivals of 33 and 34 days were achieved. The longest survival rate of greater than 52 days was obtained by a single transfusion and 25 mg/kg/day of cyclophosphamide given before transplantation. Splenectomy following 2 or 3 transfusions prolonged survival rates to 16-18 days, suggesting that mechanical removal of immunized cells is somewhat effective. Most of the antibody produced by one transfusion was IgM, as were antibodies that resulted from transfusions followed by azathioprine. It is possible that reduction of IgG-producing cells is important. These results are consistent with the clonal deletion theory, although they do not necessarily provide final proof. The experiments suggest that the optimal transfusion effect may be obtained with minimal immunization (1 transfusion) and proper immunosuppression before transplantation.

Low-dose cyclosporine maintenance therapy after immunosuppressive induction in a rat cardiac transplant model.

An immuno-reduction-suppression protocol using spleen cell infusion followed by cyclophosphamide (CP) or azathioprine (AZ) to reduce the immunocompetent cells and maintenance suppression with low-dose cyclosporine (CsA) was highly effective in a rat cardiac transplant model. Following one or two spleen cell infusions, AZ or CP treatment was given before transplantation. After transplantation the animals were maintained with low-dose CsA. Among those treated with AZ, five of eight survived greater than 100 days, and among those treated with CP, six of eight survived greater than 100. These two protocols were far superior to 28 other permutations of treatment consisting of 164 transplants, such as infusions plus AZ without CsA and infusions without AZ but with CsA. We conclude that CsA can most effectively be used in low dose as a maintenance drug and that immunoreduction therapy is optimized by prestimulation and expansion of reactive cells. Another important feature of this proposal is that the immunoreductive risk phase, performed before transplantation, can be separated from the operative risk period. This avoids the conventional superimposition of the two risks.

The benefit and underutilization of sharing kidneys for better histocompatibility.

The data of the UCLA Kidney Transplant Registry were reviewed with regard to sharing. The percentage of first-cadaver cyclosporine-treated transplants since 1984 with long cold ischemia time increased with sharing distance: 25% of unshared grafts, 40% of locally shared, and 61% of distantly shared ones had cold ischemia times over 24 hr; for cold ischemia times over 36 hr the numbers were 6%, 12%, and 24%, respectively. The immediate function rate did not parallel sharing distance the way cold ischemia time did: 85.7% without sharing, 74.4% with local sharing, and 83.5% with distant sharing. The percentage of well-matched (0 HLA-B,DR mismatches) transplants was low (3-5%) regardless of sharing status. Well-matched shared grafts with cyclosporine immunosuppression had a 9% survival advantage at one year compared with poorly matched unshared ones (85% vs. 76%). Long-term, well-matched shared grafts had a half-life of 11.9 years compared with 7.5 years for poorly matched unshared ones (reflecting graft loss from 3 to 10 years posttransplant). We conclude that sharing for histocompatibility has an overall beneficial effect.

Systemic versus nonsystemic reperfusion of the transplanted liver.

Reperfusion of the orthotopically transplanted liver can result in severe hemodynamic instability. This instability can result in the postreperfusion syndrome (PRS), which includes decreases in mean arterial pressure (MAP), systemic vascular resistance (SVR), and heart rate, and increases in central venous pressure and pulmonary capillary wedge pressure. This syndrome appears to be mediated by the left ventricular mechanoreceptor reflex (LVMRR), which can be activated by changes in preload, afterload, or left ventricular contractility, and by the infusion of alkaloids or potassium into the right atrium. In an attempt to prevent activation of the LVMRR and PRS, we have inserted a cannula into the retrohepatic vena cava and have allowed the initial 500-600 cc of portal blood reperfusing hepatic allografts to be discarded. We compared this nonsystemic reperfusion (NSRP) of livers with systemic reperfusion (SRP), in which the initial portal blood reperfusing livers is allowed to enter the systemic circulation. In the NSRP group (n = 14) there was no decrease in MAP, heart rate, or SVR, and the serum potassium did not increase after reperfusion. In the SRP group (n = 14), six patients (42%) developed PRS and there were statistically significant decreases in MAP and SVR, and increases in pulmonary capillary wedge pressure and serum potassium, as compared with the NSRP group. In conclusion, NSRP results in less hemodynamic instability during reperfusion, and should be considered the preferred method for reperfusion of the transplanted liver.

Dominant effect of histocompatibility on ten-year kidney transplant survival.

Using actuarial methods, factors influencing long-term graft survival were examined in 33,594 recent (since 1974) kidney transplants reported to the University of California, Los Angeles, Transplant Registry. One- and 10-year graft-survival rates as well as late (from 3 through 10 years) graft-loss rates (half-lives) were determined. The donor-recipient relationship had the greatest influence on long-term graft survival. Transplants between HLA-identical siblings had graft-survival rates of 89% at 1 year and 68% at 10 years, compared with 76% and 43% for parental donors, and 58% and 26% for cadaver donor transplants, respectively. These differences were also evident from the graft half-lives, which were 22 years for HLA-identical sibling, 12 years for parental, and 8 years for cadaver donor allografts. In cadaver donor transplants, matching for HLA-A,B antigens had the greatest influence on long-term graft survival, with a 15% 10-year graft survival (39% vs. 24%) and 7-year half-life (14 vs. 7 years) advantage seen with the best (zero HLA-A,B mismatches) compared with the worst (4 HLA-A,B) cases, respectively. Some of the factors studied, such as transplant number and pretransplant transfusions, tended to influence the short- rather than long-term graft-survival rates. Others, including HLA-A,B matching, early graft function and the recipient's original disease, influenced both early and late graft survival. Over all, histocompatibility between donor and recipient had by far the greatest influence on the long-term success of renal allografts.

Management of mucocutaneous herpes simplex virus infections.

Herpes simplex virus type 1 and 2 are causes of common inflammatory conditions of the mucous membranes and skin. The proper management of these infections begins with an accurate diagnosis. Viral cultures should be performed whenever possible. Patients should be counselled regarding the proper care of lesions, the risk of complications, the likelihood of experiencing recurrent infection, and should be urged to avoid intimate contact while lesions are active. Antiviral therapy is now available to ameliorate the symptoms and shorten the duration of infection in selected patients, but does not prevent recurrences. Topical, oral and intravenous preparations of acyclovir are effective in treatment of primary herpes simplex infections. Immunosuppressed patients with herpes simplex infections also benefit from acyclovir therapy. Oral activity has some activity in ameliorating recurrent genital herpes and should be considered for patients who are particularly troubled by their infections.

Double-blind comparison of weekend and daily regimens of oral acyclovir for suppression of recurrent genital herpes.

The potential utility of intermittent regimens of oral acyclovir for suppression of recurrent genital herpes depends on how long the suppressive effect of the drug persists during pauses in treatment. To study this question, we admitted 38 patients in a double-blind controlled trial comparing the results of daily acyclovir treatment (200 mg t.i.d.) with treatment on weekend days only (400 mg t.i.d. on Saturday and Sunday) for suppression of recurrent genital herpes. Of the 35 patients completing the study, significantly more failures occurred in the weekend group (13/17) than in the daily group (3/18, P less than 0.001). Failures on the weekend regimen were more frequent as the week progressed (P = 0.005). The findings suggest a short-term persistence of suppression by acyclovir and hence that intermittent regimens with more closely spaced periods of treatment may be more effective than the regimen we studied. Most virus isolates studied, including all of those isolated from the patients during treatment, were sensitive to acyclovir.

Mesenteric cysts and intra-abdominal cystic lymphangiomas.

Although mesenteric cysts and intra-abdominal cystic lymphangiomas are uncommon and clinically confusing lesions, histologic and ultrastructural evidence suggests that they are pathologically distinct. Differentiation of these lesions is important since lymphangiomas may follow a proliferative and invasive course. Of 28 cases documented at laparotomy, histologically eight patients (29%) had cystic lymphangiomas and 20 patients (71%) had mesenteric cysts. Lymphangioma was found to be exclusively a disease of childhood and young adulthood (mean age, 10 years); mesenteric cyst was found in all age groups (mean age, 44 years), and two thirds of these patients were over 40 years old. Patients with lymphangiomas more frequently were male (75% vs 30%), symptomatic (88% vs 35%), and had ascites (50% vs 0%) and larger lesions (mean, 8.8 vs 4.7 cm) when compared with patients with mesenteric cysts. Complete excision was possible in all but four patients, with no operative deaths and a postoperative complication rate of 7%. After a mean follow-up period of four years, there were no recurrences among 16 patients who had undergone complete excision.

Risk of renal failure after major angiography.

In 400 patients who underwent major aortography, acute renal dysfunction (ARD) occurred in 11.3%. Of the group with normal renal function before the procedure, 8.2% had ARD and 0.8% required dialysis. Patients with prior abnormal renal function had a 41.7% incidence of ARD, and 8.3% required dialysis as a result of angiography. Vigorous intravenous hydration was used in all patients but did not completely prevent renal problems. Two risk factors not previously emphasized were the injection site (higher risk with abdominal aortic studies) and presence of congestive heart failure requiring treatment with digoxin. Other notable risk factors included contrast load and age. These results emphasized that even with modern contrast agents and application of current concepts of treatment, there remains a risk of renal injury with major angiography.

Fluorescence-based detection of lacZ reporter gene expression in intact and viable bacteria including Mycobacterium species.

A variety of fluorescein di-beta-D-galactopyranoside (FDG)-based substrates were evaluated for measuring beta-galactosidase expression in bacteria. One substrate, 5-acetylamino-FDG (C2FDG), performed well in all bacteria tested, including the slow growing mycobacterium, Mycobacterium bovis BCG. The sensitivity of C2FDG in intact, viable BCG was similar to that of o-nitrophenyl-beta-D-galactopyranoside in cell lysates when used to measure lacZ reporter gene activity. C2FDG was approximately 70-fold more sensitive than green fluorescent protein (GFP) in BCG when assayed in a fluorescence plate reader, and comparable to GFP when measured by flow cytometry. These assays provide an important new alternative for the rapid measurement of reporter gene expression in viable bacteria.

Contribution of the multidrug efflux pump LfrA to innate mycobacterial drug resistance.

Multidrug resistance (MDR) in bacteria has been associated with efflux pumps that export structurally unrelated compounds and decrease cytoplasmic drug accumulation. To investigate MDR in mycobacteria, we studied the Mycobacterium smegmatis mutant mc(2)11, which is resistant to doxorubicin, tetracycline, rhodamine, ethidium bromide and the hydrophilic fluoroquinolones. A genomic library constructed from this mutant was used to select clones conferring resistance to doxorubicin. Surprisingly, the clone selected encodes the efflux pump LfrA, which has been reported to confer resistance to hydrophilic fluoroquinolones, ethidium bromide, rhodamine, and acriflavine. To define the contribution of LfrA to the innate mycobacterial drug resistance and to the MDR phenotype in mc(2)11, the lfrA gene was disrupted in both the mc(2)11 mutant and the mc(2)155 wild-type parent. LfrA disruption of the wild-type strain decreased resistance to ethidium bromide and acriflavine, and increased accumulation of ethidium bromide. However, disruption of lfrA gene results only in a 2-fold decrease in minimal inhibitory concentrations (MICs) for ciprofloxacin, doxorubicin, rhodamine, and accumulation of [(14)C]ciprofloxacin was unchanged. LfrA disruption of the MDR strain mc(2)11 produced a similar phenotype. Thus, LfrA contributes significantly to the intrinsic MICs of M. smegmatis for ethidium bromide and acriflavine, but not for ciprofloxacin, doxorubicin or rhodamine.

Choledochal cysts: results of primary surgery and need for reoperation in young patients.

The UCLA Medical Center experience in the surgical treatment of 23 young patients with choledochal cysts over a 28 year period has been reviewed. All patients had saccular or fusiform extrahepatic cysts, and one patient also had a diverticular cyst. Eleven patients had no intrahepatic dilatation, whereas 9 had cylindrical and 3 cystic intrahepatic dilatation. There were 39 operations for biliary drainage performed: 17 Roux-Y choledochojejunostomies, 7 choledochoduodenostomies, 7 excisions, and 8 miscellaneous procedures. The morbidity for initial operations was 17 percent and for reoperations, 31 percent. Biliary calculi were found after 2 of 23 primary operations (9 percent) and 6 of 16 reoperations (37.5 percent). All developed while enteric drainage was present and were primary bile duct stones. No reoperation was necessary after cyst excision. An intrahepatic cholangiocarcinoma developed in one patient treated with enteric drainage. Three of 10 patients who did not undergo cholecystectomy at their initial operation later required laparotomy for cholecystectomy alone. We recommend cholecystectomy and cyst excision when technically feasible for primary operative treatment of choledochal cysts.

Surgical management of peritoneal dialysis catheters in children: five-year experience with 1,800 patient-month follow-up.

Currently at our institution more than 90% of the children with end-stage renal disease are managed with continuous ambulatory peritoneal dialysis (CAPD) in preference to hemodialysis until a successful transplant is accomplished. Recent refinements in CAPD catheters and dialysis techniques have greatly added to the many medical, psychological, and economic advantages of CAPD compared with chronic hemodialysis. Ninety-three patients less than 21 years of age underwent insertion of 167 peritoneal dialysis (PD) catheters over a 5-year period. A variety of PD catheters were used, including 121 (73%) double-cuff Tenckhoff catheters, 22 (13%) single-cuff, and 24 (14%) column disc catheters (Lifecaths, Physio-Control Corp, Redmond, WA). There were three (3%) noncatheter-related mortalities and minimal significant morbidity during the 1,819 patient-months of catheter use. Exit site infections (61%) and peritonitis (59%) were frequent but minor complications, occasionally requiring catheter replacement. Other noninfectious complications included abdominal hernias (42%), dialysis leaks (14%), distal cuff extrusion (11%), catheter obstruction (7%), and hydrothorax (2%). Forty-five of the 60 hernias (75%) were surgically repaired in patients while receiving CAPD. Persistent or recurrent peritonitis was common with Pseudomonas, Serratia, and fungal infections and often resulted in catheter removal and loss of the peritoneal dialysis membrane. Catheter survival for the double-cuff Tenckhoff was significantly better (P .005) than the single-cuff or Lifecath. Based on this experience we have found that using specific operative techniques for CAPD catheter placement and early surgical management for severe peritonitis reduces the incidence of complications and modality failure.