Understanding Laboratory Methods and Their Impact on Antimicrobial Resistance Surveillance, at Muhimbili National Hospital, Dar es Salaam, Tanzania

The study sought to describe laboratory methods and blood culture procedures and their impact on antimicro-bial resistance surveillance among nosocomial bacteria. We conducted a systematic audit of blood culture pro-cedures and practices in the Department of Microbiology, Central Pathology Laboratory at Muhimbili National Hospital, between 19th and 23rd March 2012. A total of 25 - 30 blood culture specimens were received each day as an indication of low volumes of blood culturing at this site. More blood culture requests came from the neonatal unit of the hospital, and were performed manually with high culture negative specimens. The laboratory per-formed antibiotic susceptibility testing as per the CLSI guidelines. No vancomycin resistance was ever reported at this site. All blood culture results were entered into the JEEVA laboratory information system, where results could be accessed by clinicians in the wards and data could be retrieved to assess patterns of antimicrobial resis-tance. Blood culture data entry system lacked quality control checks hence numerous errors and missing data were observed. Our results support the relevance of having improved laboratory procedures and good quality blood culture since surveillance of antimicrobial resistance primarily depends on good laboratory procedures, good quality and reliable blood culture data. This would essentially minimise imprecise estimates of rates of an-timicrobial resistance at this hospital.\u

Antimicrobial resistance among producers and non-producers of extended spectrum beta-lactamases in urinary isolates at a tertiary Hospital in Tanzania

<p>Abstract</p> <p>Background</p> <p>Published data on the existence and magnitude of extended spectrum beta-lactamase (ESBL) production in urinary pathogens in local setting is limited. The aim of the present study was to determine the prevalence of antimicrobial resistance and ESBL production among <it>Escherichia coli </it>and <it>Klebsiella spp </it>from urine samples in a tertiary hospital. This was a cross sectional study conducted at Muhimbili National Hospital in Dar es Salaam, Tanzania.</p> <p>Findings</p> <p>A total of 270 <it>E.coli </it>and <it>Klebsiella spp </it>urinary pathogens from children and adults isolated from January to March 2010 were included in the study. <it>E. coli </it>and <it>Klebsiella spp </it>isolates were tested for antimicrobial susceptibility by the Clinical and Laboratory Standard Institute's disc diffusion method. These isolates were further screened for ESBL phenotype using cefotaxime and ceftazidime discs. Isolates with reduced sensitivity were confirmed using ESBL E-test strips. Of 270 isolates, 138 (51.1%) were <it>E. coli </it>and 132 (48.9%) were <it>Klebsiella spp</it>. ESBL was detected in 122 (45.2%) of all the isolates. ESBL- producing <it>E. coli </it>strains were significantly more resistance to cotrimoxazole (90.7%), ciprofloxacin (46.3%) and nalidixic acid (61.6%) than strains that did not produce ESBL (p < 0.05). Similarly, ESBL- producing <it>Klebsiella spp </it>strains were significantly more resistance to cotrimoxazole (92.6%), ciprofloxacin (25.0%), nalidixic acid (66.2%), and gentamicin (38.2%) than strains that did not produce ESBL (P < 0.05). Multi-drug resistance was found to be significantly (<it>P </it>< 0.05) more in ESBL producing isolates (90.5%) than non ESBL producers (68.9%). The occurrence of ESBL was significantly higher among isolates from inpatients than outpatients [95 (50.5%) vs. 27(32.9%)] (p = 0.008). The occurrence of ESBL was significantly higher among isolates from children than in adults [84 (54.9%) vs. 38(32.5%)] (p < 0.001).</p> <p>Conclusions</p> <p>High prevalence of ESBL-producing <it>E. coli </it>and <it>Klebsiella spp </it>strains was found among inpatients and children. Most of the ESBL- producing isolates were multi-drug resistant making available therapeutic choices limited. We recommend continued antibiotic surveillance as well comprehensive multi-center studies to address the emerging problem of ESBL-associated infections in order to preserve the continued usefulness of most antimicrobial drugs. Further more conducting molecular studies will help to evaluate the various ESBL types.</p

Virological efficacy and emergence of drug resistance in adults on antiretroviral treatment in rural Tanzania

Background Virological response to antiretroviral treatment (ART) in rural Africa is poorly described. We examined virological efficacy and emergence of drug resistance in adults receiving first-line ART for up to 4 years in rural Tanzania. Methods Haydom Lutheran Hospital has provided ART to HIV-infected patients since October 2003. A combination of stavudine or zidovudine with lamivudine and either nevirapine or efavirenz is the standard first-line regimen. Nested in a longitudinal cohort study of patients consecutively starting ART, we carried out a cross-sectional virological efficacy survey between November 2007 and June 2008. HIV viral load was measured in all adults who had completed at least 6 months first-line ART, and genotypic resistance was determined in patients with viral load >1000 copies/mL. Results Virological response was measured in 212 patients, of whom 158 (74.5%) were women, and median age was 35 years (interquartile range [IQR] 29–43). Median follow-up time was 22.3 months (IQR 14.0–29.9). Virological suppression, defined as <400 copies/mL, was observed in 187 patients (88.2%). Overall, prevalence of ≥1 clinically significant resistance mutation was 3.9, 8.4, 16.7 and 12.5% in patients receiving ART for 1, 2, 3 and 4 years, respectively. Among those successfully genotyped, the most frequent mutations were M184I/V (64%), conferring resistance to lamivudine, and K103N (27%), Y181C (27%) and G190A (27%), conferring resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs), whereas 23% had thymidine analogue mutations (TAMs), associated with cross-resistance to all nucleoside reverse transcriptase inhibitors (NRTIs). Dual-class resistance, i.e. resistance to both NRTIs and NNRTIs, was found in 64%. Conclusion Virological suppression rates were good up to 4 years after initiating ART in a rural Tanzanian hospital. However, drug resistance increased with time, and dual-class resistance was common, raising concerns about exhaustion of future antiretroviral drug options. This study might provide a useful forecast of drug resistance and demand for second-line antiretroviral drugs in rural Africa in the coming years

Bacterial isolates and drug susceptibility patterns of urinary tract infection among pregnant women at Muhimbili National Hospital in Tanzania

Urinary tract infection (UTI) during pregnancy may cause complications such as pyelonephritis, hypertensive disease of pregnancy, anemia, chronic renal failure, premature delivery and fetal mortality. This study aimed to identify the etiologic agents of UTI and to determine the patterns of antimicrobial drug susceptibility among pregnant women at Muhimbili National Hospital in Tanzania. Retrospective analysis of 200 mid-stream urine specimens processed for culture and antimicrobial drug susceptibility testing between January 2007 and December 2009 was carried out. Significant bacteriuria (> 105 colony forming units/mL of urine) was found in 42/200 (21%) specimens. Of the 42 isolates, the most commonly isolated bacteria were Escherichia coli 14 (33.3%), Klebsiella spp 9 (21.4%) coagulase negative Staphylococcus 7 (16.7%), Staphylococcus aureus 6 (14.3%), Proteus species 3 (7.1%) and Enterococcus species 3 (7.1%). Low rate to moderately high rate of antimicrobial drug resistance was observed against first line drugs namely, nitrofurantoin 18.7 % (n=16), co-trimoxazole 38.5 % (n=13) and ampicillin 57.7 % (n=26). Relatively low rate of resistance was seen against second line drugs: ciprofloxacin 13.6 % (n=22) and amikacin 5 % (n=20). High rate of resistance was observed in third generation cephalosporin cefotaxime 31.2 % (n=16). Of the Gram-positive organisms tested against vancomicin and methicilin, resistance was found in 25 % (n=13) and 25 % (n=4), respectively. In conclusion, E coli was found to be the common cause of UTI among the pregnant women. Low to moderately high level of resistance was found in first line drugs while high level of resistance was found in third generation cephalosporin. It is recommended to monitor the levels of resistance for nitrofurantoin, fluoroquinolone and cefotaxime and to screen for Extended Spectrum Beta Lactamase production among cefotaxime resistant E. coli and Klebsiella spp

Divergence and Recombination of Clinical Herpes Simplex Virus Type 2 Isolates▿

Herpes simplex virus type 2 (HSV-2) infects the genital mucosa and is one of the most common sexually transmitted viruses. Here we sequenced a segment comprising 3.5% of the HSV-2 genome, including genes coding for glycoproteins G, I, and E, from 27 clinical isolates from Tanzania, 10 isolates from Norway, and 10 isolates from Sweden. The sequence variation was low compared to that described for clinical HSV-1 isolates, with an overall similarity of 99.6% between the two most distant HSV-2 isolates. Phylogenetic analysis revealed a divergence into at least two genogroups arbitrarily designated A and B, supported by high bootstrap values and evolutionarily separated at the root. Genogroup A contained isolates collected in Tanzania, and genogroup B contained isolates collected in Tanzania and Scandinavia, implying that the genetic variability of HSV-2 is higher in Tanzania than in Scandinavia. Recombination network analysis and bootscan analysis revealed a complex pattern of phylogenetically conflicting informative sites in the sequence alignments. These signals were present in synonymous and nonsynonymous sites in all three genes and were not accumulated in specific regions, observations arguing against positive selection. Since the PHI test applied solely to synonymous sites revealed a high statistical probability of recombination, we suggest as a novel finding that homologous recombination is, as reported earlier for HSV-1 and varicella-zoster virus, a prominent feature in the evolution of HSV-2

Antibiotic Resistance in Young Children in Kilosa District, Tanzania 4 Years after Mass Distribution of Azithromycin for Trachoma Control.

Mass administration of azithromycin (MDA) is integral to trachoma control. Recent studies suggest that MDA may increase drug-resistant pathogens, yet findings from prior studies suggest little long-term impact on resistance. This disparity may be linked to differences in pre-MDA community-level resistance patterns. We describe carriage prevalence and antibiotic resistance patterns for Streptococcus pneumoniae (Spn) (nasopharyngeal swab collection), Staphylococcus aureus (SA) (nasopharyngeal swabs), and Escherichia coli (EC) (rectal swabs) in 1,047 children ages 1-59 months in a district with MDA cessation 4 years ago. Antibiotic susceptibility was evaluated by disk diffusion and Etest. The carriage rates for Spn, SA, and EC were 43.5% (455/1,047), 13.2% (138/1,047), and 61.7% (646/1,047), respectively. Resistance to AZM was observed in 14.3%, 29.0%, and 16.6% of the Spn, SA, and EC isolates, respectively. Spn resistance was variable (0-67%) by hamlet. Future analyses will assess the influence of pre-MDA antibiotic resistance patterns on those observed following MDA