Rate Of Primary Drug Resistance Research Articles

Primary drug resistance of M. tuberculosis according to the Center of Excellence of the WHO Network of Supranational Reference Laboratories of the CTRI in 2016–2021

ntroduction. Culture research and testing of Mycobacterium tuberculosis (MBT) for drug susceptibility in the Russian Federation is carried out with uneven qual-ity, which distorts the idea of primary drug resistance (DR). Aim. To study the primary DR of MBT to the main combinations of anti-TB drugs for 2016–2021 according at the Center of Excellence of the WHO Supranational Reference Laboratories Network at the Central Tuber-culosis Research Institute. Methods. Data on drug sus-ceptability and frequency of resistance to the main com-binations of anti-TB drugs (in accordance with updated definitions) of MBT isolated before treatment were stud-ied in 966 new TB cases from 69 regions of the Russian Federation examined at the Center of Excellence of the WHO Supranational Reference Laboratories Network at the Central Tuberculosis Research Institute from 2016 to 2021. Results. The rate of any primary drug resistance to rifampicin was 46.2%; 95% CI [43.0–49.3], MDR — 45.8%; 95% CI [42.6–48.9], pre-XDR — 24.2%; 95% CI [21.5–27.0], XDR — 5.4%; 95% CI [3.3–8.0]. Over time, there was a decrease in primary MDR MBT from 48.7% in 2016 and 54.9% in 2017 to 36.8% in 2021. The frequency of pre-XDR did not change during the observation peri-od. There was a statistically significant increase in the incidence of primary XDR from 2.1%; 95% CI [0.4–11.1] in 2016 and 0.0% in 2017 to 11.0%; 95% CI [6.1–19.1] in 2021 (p=0.03). Conclusion. The rate of primary MBT drug resistance to the main anti-TB combinations, ac-cording to our study, significantly exceeds the overall figures for Russian Federation. This suggests that the situation with MDR, pre-XDR, and XDR tuberculosis in the Russian Federation is much more alarming than we see from the regular reports, while the quality of local microbiological diagnostics on is insufficient

Curative Efficacy of First Generation TKI in the Treatment of CML-CP Combined with vPh and Analysis of Its Genetic Characteristics

To investigate the curative efficacy of first generation TKI in the treatment of CML-CP combined with vPh and genetic characteristics. 60 patients with CML-CP combined with vPh from January 2010 to May 2017 in the First Affiliated Hospital of Kunming Medical University were chosen as CML-CP-vPh group, and 107 patients with CML-CP combined with typical Ph chromosome at the same time were chosen as control group. The patients in two groups were treated with imatinib; The curative efficacy, karyotype and FISH signal type were compared between 2 groups, and the factors influencing long-term survival of patients were analyzed by Cox risk model. There was no significant difference in the demographic and hematological baseline data between 2 groups (P＞0.05), and there was no significant difference in the incidence of drug-resistance between 2 groups (P＞0.05). The incidence of primary drug-resistance and primary hematological drug-resistance in the CML-CP-vPh group were significantly higher than that in control group (P＜0.05). There was no significant difference in the accumulative CCyR rate, accumulative MMR rate, OS and EFS between 2 groups (P＞0.05). Multivariate Cox model analysis showed that vPh not correlated with OS and EFS of patients with CML-CP (P＞0.05). The factors influencing OS in CML-vPh patients included high risk of Sokal scores, peripheral blood basophils proportion ≥10%, BCR-ABLIS in 3 months after treatment＜10%, achieviag CCyR in 6 months after treatment and achieviag MMR in 12 months after treatment (P＜0.05). The factors influencing EFS included BCR-ABLIS＜10% in 3 months after treatment and achieving MMR in 12 months after treatment (P＜0.05). The regions with high frequency of heterotopic involvement included 12q1, 12q2 [9 cases (15.00%)] and 1p3 [8 cases (13.33%)]. The percentage of 2G2R1Y, 1G1R2F, 1G2R1Y, 2G1R1Y and 1G1R1Y in FISH signal types were 73.33%, 10.00%, 1.67%, 1.67% and 1.67% respectively. Patients with CML-CP combined with vPh possess higher primary drug-resistance rate and primary hematological drug-resistance rate for the first generation TKI, while second-generation TKI can efficiently improve long-term survival, its efficacy is similar to efficacy for patients with typical Ph chromosomes. CML-CP combined with vPh does not display special demographic and hematological characteristics. The main involved regions of heterotopic variants include 12q1, 12q2 and 1p3, while 2G2R1Y type is the most common type of FISH signal.

Primary drug resistance of mycobacterium tuberculosis in Shandong, China, 2004\u20132018

BackgroundPrimary drug-resistant tuberculosis (DR-TB) has contributed to a significant health and economic burden on a global scale, especially in China. we sought to estimate epidemiological characteristics of primary DR-TB in China from 2004 to 2018.MethodsEleven thousand four hundred sixty-seven newly diagnosed and 1981 retreated TB cases with drug susceptibility data were included. Chi-Square test for trends, linear regression, a joinpoint regression model and temporal trend in proportions of the different resistance patterns were carried out.ResultsThe proportion of primary DR-TB and mono-resistant TB (MR-TB) in China had reduced by more than 12% since 2004, and were 21.38%, 13.35% in 2018 respectively. Among primary DR-TB cases (2173,18.95%), the percentage of multiresistant TB (MDR-TB, from 5.41 to 17.46%), male (from 77.03 to 84.13%), cavity (from 13.51 to 43.92%), rifampicin(RFP)-resistant TB (from 8.11 to 26.98%), streptomycin(SM)-resistant TB (from 50.00 to 71.43%) increased significantly (P < 0.05). On the contrary, the proportion of female, non-cavity, isoniazide(INH)-resistant TB (from 55.41 to 48.15%) and MR-TB (from 82.43 to 62.43%) decreased significant (P < 0.05). The primary drug resistance rate among female, cavity, smoking, drinking, 15 to 44 year-old TB subgroups increased by 0.16, 6.24, 20.95, 158.85, 31.49%, respectively. The percentage of primary DR-TB, RFP-resistant TB dropped significantly during 2004–2007 in Joinpoint regression model.ConclusionThe total rate of drug resistance among new TB cases showed a downward trend in Shandong, China, from 2004 to 2018. Primary drug resistance patterns were shifting from female, non-cavity, INH-resistant TB, and MR-TB groups to male, cavity, RFP/SM-resistant TB, and MDR-TB groups. Considering the rising drug resistance rate among some special population, future control of primary DR-TB in China may require an increased focus on female, cavity, smoking, drinking, or 15 to 44 year-old TB subgroups.

HIV genetic subtypes and HIV drug resistance in China: a Meta-analysis

Objective: To assess the relationship between HIV genetic subtypes and HIV resistance in China. Methods: The literature retrieval was conducted by using Chinese Science-Technology Journal Database (VIP), Wanfang Data, Chinese Journal Full-text Database (CNKI), PubMed and Web of Science to select the papers on the relationship between HIV subtypes and HIV drug resistance in China during 2005-2015. Eligible papers were included according to the inclusion. Meta-analysis was performed by using software Stata 12.0. Results: A total of 43 papers were selected and the pooled rate of drug resistance was 15.1% and the rate of primary drug resistance was 9.5%, the subtypes associated drug resistance were CRF01_AE, CRF07_BC, CRF08_ BC, B/B'and C. The pooled rates of drug resistance of each subtype were 12.8%, 7.4%, 14.3%, 25.7% and 34.9% and the rates of primary drug resistance of each subtype were 7.3%, 5.7%, 11.5%,15.5% and 23.9%, respectively. Subgroup analysis showed that both treated and area subgroup showed a significant difference among groups (P<0.05). The rates of primary resistance of each subtype in northern China and southwestern China were higher than that in southern China. Conclusion: The distribution of HIV genotypes in China was complex and the prevalence of primary drug resistance of each subtype was high, together with a significant difference among subtypes. It is necessary to strengthen the monitoring of different subtypes of drug resistant strains in China to prevent the recombination and spreading of resistant strains.

Gene mutations of human immunodeficiency virus drug resistance from men who have sex with men in Shanghai, 2013

Objective To investigate the gene mutations of human immunodeficiency virus (HIV)-1 drug resistance among anti-retrovirus (ARV) treated-naive men who have sex with men (MSM) in Shanghai to provide evidence-based data for optimized treatment. Methods All 669 treatment-naive cases of HIV-1 infection identified among MSM in 2013 were recruited and their plasma was collected. RNA was extracted and amplified by nest reverse transcription-polymerase chain reaction, and DNA was sequenced and then phylogenetically analyzed. Finally, subtypes were identified and drug resistance was analyzed in comparison with International HIV Drug Resistance Database. Results The pol gene fragments of 645 cases were obtained. Primary drug-resistance rate was 2.48% (16/645), including mutations conferring resistance to protease inhibitor (PI) (0.31%, 2/645), nucleoside reverse transcriptase inhibitors (NRTI) (0.16%, 1/645), non-nucleoside reverse transcriptase inhibitors (NNRTI) (1.70%, 11/645) and both NRTI and NNRTI (0.31%, 2/645), respectively. Mutations conferring resistance to CRF01_AE were 12 cases (2.99%), while mutations conferring resistance to CRF07_BC and CRF_01B were 0.61% (1/163) and 4.65% (2/43) including 1 case of CRF52_01B and unidentified CRF_01B, respectively. Resistance to NNRTI in B subtype were 2.70% (1/37). Conclusion The prevalence of HIV-1 drug resistance-associated mutations among MSM in Shanghai, 2013 is still low, but resistance to NNRTI is relatively high. CRF01_AE is the major subtype of drug resistance. It is necessary to strengthen the HIV drug resistance surveillance in MSM group in Shanghai. Key words: Human immunodeficiency virus-1; Homosexuality, male; Subtype/recombinant; Drug resistance

HIV-1 drug resistance in recently HIV-infected pregnant mother’s naïve to antiretroviral therapy in Dodoma urban, Tanzania

BackgroundHIV resistance affects virological response to therapy and efficacy of prophylaxis in mother-to-child-transmission. The study aims to assess the prevalence of HIV primary resistance in pregnant women naïve to antiretrovirals.MethodsCross sectional baseline analysis of a cohort of HIV + pregnant women (HPW) enrolled in the study entitled Antiretroviral Management of Antenatal and Natal HIV Infection (AMANI, peace in Kiswahili language). The AMANI study began in May 2010 in Dodoma, Tanzania. In this observational cohort, antiretroviral treatment was provided to all women from the 28th week of gestation until the end of the breastfeeding period. Baseline CD4 cell count, viral load and HIV drug-resistance genotype were collected.ResultsDrug-resistance analysis was performed on 97 naïve infected-mothers. The prevalence of all primary drug resistance and primary non-nucleoside reverse-transcriptase inhibitors resistance was 11.9% and 7.5%, respectively. K103S was found in two women with no M184V detection. HIV-1 subtype A was the most commonly identified, with a high prevalence of subtype A1, followed by C, D, C/D recombinant, A/C recombinant and A/D recombinant. HIV drug- resistance mutations were detected in A1 and C subtypes.ConclusionOur study reports an 11.9% prevalence rate of primary drug resistance in naïve HIV-infected pregnant women from a remote area of Tanzania. Considering that the non-nucleoside reverse-transcriptase inhibitors are part of the first-line antiretroviral regimen in Tanzania and all of Africa, resistance surveys should be prioritized in settings where antiretroviral therapy programs are scaled up.

Efficacy of first-line antiretroviral therapy: differences between hospital-based outpatient units and private practices in Germany

Purpose of the study : The efficacy of highly active antiretroviral therapy of HIV-infection (HAART) is influenced by factors like potency of applied drugs, adherence of the patient, or resistance-associated mutations. Up to now, there is little evidence about the impact of the therapeutic setting. Methods: Since 2001, the prospective multicenter study RESINA examines the epidemiology of primary HIV drug resistance in Nordrhein-Westfalen, the biggest federal state of Germany. Longitudinal data of all participants are followed in a cohort. Parameters of patients treated in hospital-based outpatient units were compared to those of participants treated in private practices. All 36 centers were specialized in the care for HIV and AIDS patients. Summary of results: Altogether, 1591 patients were enrolled from 2001 to 2009 with a follow-up until the end of 2010. 1099 cases were treated in hospital-based units, 492 were treated in private practices. Significant differences were found considering baseline characteristics. Patients with further progressed disease and more non-European individuals were cared for in hospital units. Only median age and the rate of primary drug resistance were not significantly different. After 48 weeks, 81.9% of patients in hospital units and 85.9% in private practices had a viral load below the limit of detection (p=0.12). A similar result was seen after 96 weeks (p=0.54). A comparable increase of CD4 cell-count was determined in both groups. Conclusions : The RESINA study covers a large cohort treated in different specialized facilities. We found significant differences in baseline characteristics with more unfavourable parameters in cases at hospital-based units compared to private practices. Nevertheless, treatment outcome was similar up to 2 years after therapy initiation. In conclusion, adminstration of HAART is highly efficacious regardless of treatment setting in Germany.

HBV Primary Drug Resistance in Newly Diagnosed HIV–Hbv-Coinfected Individuals in Spain

The wide use of lamivudine (3TC) as oral therapy for chronic HBV infection has favoured the selection and circulation of 3TC-resistant HBV strains worldwide. Although transmission of 3TC-resistant HBV variants has been reported only sporadically, few studies have been conducted in the HIV population where exposure to 3TC has been greater forming part of antiretroviral therapy (ART) regimens. All individuals positive for serum hepatitis B surface antigen (HBsAg), newly diagnosed with HIV-1 infection, naive to ART and enrolled in the Spanish HIV cohort (CoRIS) since 2004 were identified. The HBV polymerase gene was sequenced and drug resistance mutations were characterized retrospectively in stored frozen plasma specimens. From 4,419 ART-naive HIV-1-infected individuals, 223 (5.1%) were positive for serum HBsAg. Baseline stored sera were available for 84 patients, of whom 73 could be characterized virologically. This population was mainly represented by men who had sex with men (52.1%), native Spaniards (65.7%) and Latin Americans (16.4%). The mean age was 36 years, mean CD4(+) T-cell count 375 cells/mm(3) and mean plasma HIV RNA 4.5 log(10) copies/ml. The HBV genotype distribution was 64% A, 20% F, 12% D and 4% others. Drug-resistant mutations in the HBV polymerase were found in four (5.5%) patients: two harboured rtL180M, one rtL80V and one rtV173L. The rate of primary drug resistance in HBV among newly diagnosed HIV-HBV-coinfected patients in Spain is currently low (5.5%) and restricted to 3TC. Thus, HBV drug resistance testing before prescription of oral antiviral therapy is not warranted, although periodic surveillance might be recommended.

The investigation and analysis of the current status of drug-resistant tuberculosis among migratory population in Chaoyang district in Beijing

Objective To investigate the latest situation in the period 2006-2008 of drug resistance tuberculosis among migratory population in Chaoyang district of Beijing.Methods All sputum culture-positive specimens from migratory population were collected.Drug susceptibility of Mycobacterium tuberculosis to M,H,R and E were tested by proportion method.Results Drug susceptibility of 371 isolates from 2006-2008 were tested.Total drug resistance wag 22.4%(83/371),the primary drug resistance and the acquired drug resistance were 17.5%(58/331)and 62.5%(25/40)respectively.The multi-drug resistance was 5.9%(22/371);the primary multi-drug resistance was 4.2%(14/331)and acquired multi-drug resistance wag 20.0%(8/40).The drug resistance and multi-drug resistance were higher in treated cases than that in new cases.and the difference wag statistically significant(χ~2 was 39.020 and 13.210,P<0.01).The drug resistance to 4 anti-tuberculosis drugs from high to low was M(16.7%).H(12.1%),R(11.3%),E(1.9%).The primary drug resistance rate were 13.3%(S),8.8%(H),8.2%(R),1.8%(E).The acquired drug resistance rate were 45.5%(S),40.0%(H),37.5%(R),2.5%(E).The drug resistance to S,H and R were higher in treated cases than that in new cases,and the difference was statistically significant(χ~2 was 23.549,29.810 and 27.754,P<0.01).Conclusion The drug resistance to mycobacterium tuberculosis among migratory population was relatively high in chaoyang district of Beijing,suggesting the necessity to strength the tuberculosis control program for migratory population. Key words: Mycobacterium tuberculosis; Drug resistance,bacterial; Residential mobility

HIV Drug Resistance-Associated Mutations in Antiretroviral Naïve HIV-1-Infected Latin American Children.

Our goal was to describe the presence of HIV drug resistance among HIV-1-infected, antiretroviral (ARV) naïve children and adolescents in Latin America and to examine resistance in these children in relation to drug exposure in the mother. Genotyping was performed on plasma samples obtained at baseline from HIV-1-infected participants in a prospective cohort study in Brazil, Argentina, and Mexico (NISDI Pediatric Study). Of 713 HIV-infected children enrolled, 69 were ARV naïve and eligible for the analysis. At enrollment, mean age was 7.3 years; 81.2% were infected with HIV perinatally. Drug resistance mutations (DRMs) were detected in 6 (8.7%; 95% confidence interval 3.1–18.2%) ARV-naïve subjects; none of the mothers of these 6 received ARVs during their pregnancies and none of the children received ARV prophylaxis. Reverse transcriptase mutations K70R and K70E were detected in 3 and 2 subjects, respectively; protease mutation I50 V was detected in 1 subject. Three of the 6 children with DRMs initiated ARV therapy during followup, with a good response in 2. The overall rate of primary drug resistance in this pediatric HIV-infected population was low, and no subjects had more than 1 DRM. Mutations associated with resistance to nucleoside reverse transcriptase inhibitors were the most prevalent.

Both Human Immunodeficiency Virus Cellular DNA Sequencing and Plasma RNA Sequencing Are Useful for Detection of Drug Resistance Mutations in Blood Samples from Antiretroviral-Drug-Naive Patients

Genotypic antiretroviral testing is recommended for newly infected drug-naive subjects, and the material of choice is plasma RNA. Since drug resistance mutations (DRMs) may persist longer in cellular DNA than in plasma RNA, we investigated whether the use of peripheral blood mononuclear cell (PBMC) human immunodeficiency virus (HIV) DNA increases the sensitivity of genotypic testing in antiretroviral-drug-naive subjects. We compared the rate of primary drug resistance in plasma RNA and PBMC DNA in 288 HIV type 1-infected drug-naive persons tested at a single clinical virology center from June 2004 to October 2006. Resistance in the plasma compartment to at least one drug was detected for 64 out of 288 (22.2%) naive patients and in the PBMC compartment for 56 (19.4%) patients. Overall, DRMs were found in 80 out of 288 (27.8%) patients. PBMC DNA [corrected] DRMs were present in [corrected] 16 subjects with wild-type virus in their plasma RNA [corrected] Another nine patients had additional DRMs in their PBMC DNA [corrected] with respect to those detected in their [corrected] plasma RNA. On the other hand, extra plasma RNA [corrected] DRMs were detected in [corrected] 24 and 8 subjects with wild-type and drug-resistant virus in their PBMC DNA [corrected] respectively. Resistance to more than one class of antiretroviral drug was detected by plasma and PBMC analysis for 25.0% and 36.2% of the subjects, respectively. Our data support the potential utility of genotypic resistance testing of PBMC DNA in conjunction with the currently recommended plasma RNA analysis.

Resistencias de Mycobacterium tuberculosis en el área del Hospital de Sagunto desde 1999 al 2004

This study aimed to know the drug resistance patterns of Mycobacterium tuberculosis, specifically primary drug resistance to isoniazid, in the area of the Hospital de Sagunto and to study the clinical characteristics and the risk factors associated with them.Patients included were those who were diagnosed of tuberculosis and whose M. tuberculosis strains were isolated in culture of a clinical sample and in whom a susceptibility test against the first line anti-tuberculosis drugs was performed from January 1999 to December 2004. Risk factors and clinical characteristics of the patients were gathered from the case- history.The total number of strains isolated was 77 and the global rate of resistance was 14.1%. Rate of primary drug resistance was 12.1%, and acquired 27%. No multidrug resistant case was detected. Primary drug resistance was 3% to isoniazid, 3% to rifampin, 3% to pyrazinamid, 4.5% to ethambutol and 3% to streptomycin. Acquired drug resistance was 9.1% against isoniazid and 27% against streptomicin, no resistance against the other drugs tested being found.The low level of primary drug resistance against isoniazid allows us to start treatment with three-drug regimes in new cases of native population. In our hospital area, the risk factors associated with drug resistances were smoking habit and alcoholism. Although all patients with drug resistance presented pulmonary disease, the differences were not statistically significant. However, the higher rate of pleural effusion in patients with drug resistance was statistically significant.

Mycobacterium tuberculosisDrug Resistance, Ghana

<i>Mycobacterium tuberculosis</i>Drug Resistance, Ghana

Does DOTS work in populations with drug-resistant tuberculosis?

Directly observed therapy (DOTS) is the main strategy for prevention and control of tuberculosis worldwide. However, its effect on tuberculosis transmission in populations with moderate rates of drug-resistant disease is not known. This population-based prospective study in southern Mexico between March, 1995, and February, 2000, was based on passive case finding and detection of acid-fast bacilli in sputum samples to diagnose pulmonary tuberculosis. We also used cultures, drug-susceptibility testing, bacterial genotyping, and monitoring of treatment outcomes. We enrolled 436 patients; the HIV seroprevalence rate was 2%. We used three indicators to monitor continuing tuberculosis transmission: the incidence rate of pulmonary tuberculosis, which decreased by 54.4% between 1995 and 2000, from 42.1 to 19.2 per 10(5) population (p=0.00048); the percentage of clustered pulmonary tuberculosis cases, which decreased by 62.6% from 22% to 8% (p=0.02); and the rate of primary drug resistance, which decreased by 84.0% from 9.4 to 1.5 per 10(5) population (p=0.004). Rates of multidrug-resistant (MDR) tuberculosis also decreased (p<0.0001). The case-fatality ratio was 12% for MDR tuberculosis (five of 41), 7% for strains resistant to at least one drug after exclusion of MDR (four of 55), and 3% for pansusceptible strains (nine of 272). There were 13 treatment failures (11%) in 1995 and one (2%) in 2000 (p=0.012). Even in settings with moderate rates of MDR tuberculosis, DOTS can rapidly reduce the transmission and incidence of both drug-susceptible and drug-resistant tuberculosis. However, further interventions, such as drug-susceptibility testing and standardised or individualised treatment regimens, are needed to reduce mortality rates for MDR tuberculosis.

Primary drug resistance and molecular epidemiology of Mycobacterium tuberculosis isolates from patients in a population with high tuberculosis incidence in Turkey.

To determine the rate of primary drug resistance and compare the fingerprint pattern diversity of the resistant and sensitive Mycobacterium tuberculosis isolates, antituberculosis susceptibility testing and restriction fragment length polymorphism (RFLP) analysis were performed on 88 M. tuberculosis isolates of the patients who were diagnosed as new tuberculosis cases in 2000. Primary resistance to isoniazid, rifampicin, ethambutol, and streptomycin were determined by the BACTEC method. IS6110 and pTBN12 were used as molecular markers. The frequency of resistance to at least one drug was 32.95%, whereas 10.23% of the isolates were resistant to more than one drug. Single-drug resistance to isoniazid, streptomycin, ethambutol, and rifampicin was found in 9 (10.22%), 7 (7.95%), 4 (4.54%), and 0 (0.0%) strains, respectively. Two M. tuberculosis strains (2.26%) showed multiple drug resistance. The combination of two fingerprinting procedures on a total of 88 isolates identified 58 (65.9%) strains as unique and clustered 30 strains in 11 clusters (clustering = 34.1%). The clustering rate for resistant and sensitive isolates was 13.8% and 40.1%, respectively. In conclusion; drug susceptibility testing showed that the majority of the drug-resistant infections involved either isoniazid or streptomycin alone. In addition to the high tuberculosis incidence, elevated primary drug resistance and high clustering rate indicate problems in the present control programs. New control strategies supported by molecular typing might be more effective to reduce tuberculosis.

Drug-resistant tuberculosis in a tertiary referral teaching hospital of Korea.

Background :Resistance of Mycobacterium tuberculosis strains is an increasing problem worldwide. Our purpose was to determine the prevalence of drug resistance (DR) and risk factors of DR in patients with tuberculosis and to assess the clinical characteristics and socioeconomic status of patients with drug-resistant tuberculosis.Methods :We retrospectively studied drug susceptibility tests and clinical and socioeconomic records for 308 cases of culture-positive Mycobacterium tuberculosis infection, diagnosed at Mokdong Hospital, Ewha Womans University from March, 1995 to February, 2000.Results :DR to at least one drug was identified in 75 (24.4%); the rate of primary DR, 18.7% and acquired DR, 39.3%. Multi-drug resistance (MDR) was identified in 31 (10.1%); primary MDR, 7.0% and acquired MDR, 21.4%. The risk factors of DR were previous TB treatment, pulmonary involvement and associated medical illness. DR group showed lesser adherence to treatment than the drug-sensitive group. DR group showed more frequent self-interruption of medication, lower completion rate of treatment and higher failure rate of follow-up than the drug-sensitive group. In previously treated tuberculosis patients, higher rate of overall DR and MDR, larger number of resistant drugs and more frequent self-interruption of medication were observed than newly diagnosed patients. Among DR group, acquired DR (ADR) group was older, less educated and treated for longer duration and had more advanced disease than primary DR group.Conclusion :Previously treated tuberculosis is a most important risk factor for DR. DR group, especially ADR, showed less compliance with treatment. More proper education and attention to prevent self-interruption should be given to a previously treated group. In TB prevalent areas, it should be considered to obtain initial drug susceptibility testing in high risk of DR.

Sensitivity to anti-tuberculosis drugs in HIV-positive and -negative patients in Addis Ababa.

A cross-sectional survey was conducted between 1 August and 31 December, 1998 in Addis Ababa, Ethiopia to determine the rate of primary drug resistance to anti-tuberculosis drugs and to investigate its possible association with HIV infection. Sputum culture, sensitivity to first-line anti-tuberculosis drugs and HIV testing were done for 236 sputum smear-positive pulmonary tuberculosis patients. Primary drug resistance level (single or multidrug resistance) had not changed significantly since 1994. Primary resistance occurred more often among HIV-positive than among HIV-negative patients. The association between drug resistance and HIV will have a serious impact in the control of tuberculosis because in recent years the prevalence of HIV has increased dramatically in Ethiopia. Therefore, further studies on drug resistance and HIV infection and the establishment of drug resistance surveillance are recommended.

A study on drug resistance of newly admitted pulmonary tuberculosis patients with special reference to the resistance to SM, INH, EB and RFP

Previously untreated 347 tuberculosis patients newly admitted to our hospital from 1980 to 1991 with positive bacilli and the full record of the drug sensitivity tests were analysed in this study. Among them, 49 cases showed primary resistance to either of major 4 anti-tuberculosis drugs (SM, INH, EB, RFP). The results obtained were as follows: 1. The number of patients with positive bacilli increased with age. The rate of primary drug resistance in patients of age group below 49 were significantly higher than that of age group over 50. 2. The rate of resistance was 8.6% to SM, 4.0% to INH, 1.4% to RFP and 0.6% to EB. These results are consistent with the results of studies of the Tuberculosis Research Committee, Ryoken. EB was frequently substituted to resistant drugs. 3. There was no significant difference between a group with primary resistance and a sensitive group in the various risk and intractable factors, laboratory data as a indicator of risk factors, and in the results of tuberculin skin test. There was also no significant difference in the rate of culture negative conversion of tubercle bacilli and the improvement in radiological findings. 4. We could rarely find the source of infection in 49 cases with primary resistance. In only 5 cases, family contacts were suspected and in another 1 case, the contact in a work place was suspected.

Resistance to antituberculosis drugs in Riyadh, Saudi Arabia

The prevalence of resistance to antituberculosis drugs in Riyadh was found to be 21.3%, while the rate of primary drug resistance was 11.5%. Resistance to isoniazid was the most common (19.4%) followed by rifampicin and streptomycin. The prevalence of primary and acquired rifampicin resistance was 3 and 33.7% respectively. The majority of isolates from patients with acquired resistance to rifampicin were resistant also to isoniazid.

Group III Atypical Mycobacterial Infections

We retrospectively and prospectively examined the clinical presentation, course of disease, and response to therapy in 63 patients whose mycobacterial isolates were identified as Runyon group III atypical mycobacteria. All of the patients except four had pulmonary disease similar to typical pulmonary tuberculosis. The others had scrofula or abxcess. There was a male predominance and whites were slightly more frequently infected in our series. Forty-six percent of the patients were from rural Oklahoma. Skin testing and chest roentgenography were important, but culture of the organism appeared to be the only productive method of distinguishing the atypical disease from typical tuberculosis. Eighty-one percent had an associated disease. The isolates showed a very high rate of primary drug resistance, and this was reflected in the difficulty in controlling the infection.