Clinical, molecular and drug sensitivity pattern of mycobacterial isolates from extra-pulmonary tuberculosis cases in Addis Ababa, Ethiopia.

BACKGROUND: In conjunction with the spread of HIV infection, tuberculosis (TB) remains a major cause of illness and death worldwide. The Ethiopian national report reveals that extra pulmonary tuberculosis is on the rise and that case detection rate is exceeding that of smear positive or negative cases in many parts of the country. Different studies indicated that host and/or pathogen related factors are associated with the rise of extra pulmonary cases. However, the reason for this is not clearly known in our setting. METHODS: Specimens were taken from clinically suspected extra pulmonary patients and confirmed by cytology, histopathology and culture. Deletion typing and Spoligotyping was utilized to identify the strains. The isolates were then assigned to lineage using conformal Bayesian network (rules model) algorithm and dendrograms were drawn using UPGMA methods. In addition, drug sensitivity test was done using the indirect proportion and 24 well plate methods. RESULTS: Out of the 200 clinically suspected extra pulmonary tuberculosis patients, 106 (53 %) were between 15 and 35 years of age and 167 (83.5 %) were new while 33 (16.5 %) were retreatment cases. The culture yield was 29.5 % (59). Of these only one was M. bovis and 58 were M. tuberculosis strains with 31 different spoligotype patterns grouped into seven clusters. The largest cluster (ST53) comprised 12 (20.3 %) isolates. There was higher clustering of CAS isolates in TBLN than in any other form of extra pulmonary tuberculosis cases. Resistance to rifampicin was higher (22 %) than that for INH, STM and EMB (8.1 %, 5 % and 3 % respectively). Out of the 37 isolates tested for resistance, only 2 isolates were resistant for both STM and INH and no MDR strain was found. CONCLUSIONS: There is an ongoing active recent transmission among extra pulmonary tuberculosis in the study areas as shown by the presence of clusters. Although no MDR case was observed, there is a risk of emergence of MDR as noted from the high proportion of resistance to rifampicin. Detailed study at population level is recommended to monitor its trend.

Impact of hepatitis C virus co-infection on HIV patients before and after highly active antiretroviral therapy: an immunological and clinical chemistry observation, Addis Ababa, Ethiopia.

BACKGROUND: Hepatitis C virus (HCV) is an RNA virus which has been known to cause acute and chronic necro-inflammatory disease of the liver. It is the leading cause of end-stage liver disease and hepatocellular carcinoma. HIV is known to have a negative impact on the natural disease outcome and immune response of HCV infection, whereas the reverse remains unclear. We evaluated the impact of HCV co-infection on recovery of CD4+ and CD8+ T-cells and liver enzyme levels before and after initiation of highly active antiretroviral therapy (HAART) in HIV/HCV co-infected patients. METHODS: A hospital-based, observational, prospective cohort study design was used for this study. Pre-antiretroviral treatment (Pre-ART) and under HAART HIV mono-infected and HCV/HIV co-infected individuals who are under regular follow-up were recruited for this study. 387 blood samples were collected from volunteer, known HIV positive Ethiopian patients and screened for HCV. Twenty five HCV/HIV co-infected patients were prospectively followed for four years. CD4+ and CD8+ T-cells and liver enzyme levels were determined annually for each of the participant. RESULTS: The prevalence of HCV/HIV co-infection in this study was 6.5%. Both HCV/HIV co-infected and HIV mono-infected under HAART groups showed CD4+ recovery (343 Vs 426; P < 0.004, OR = 4.97, 95% CI = 2.41 to 10.27) respectively; but, the recovery rate was higher in mono-infected (80 Vs 426) than co-infected group (148 Vs 343). The recovery and/or decline pattern of CD8+ T-cells was the same with that of CD4+. In 75% of co-infected groups, the mean alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were above the upper limit of normal reference range. Analyses restricted to individuals who initiated HAART and pre-ART showed similar results. CONCLUSION: We found that CD4+ T-cell recovery was negatively affected by the presence of ongoing HCV replication in under HAART co-infected individuals and fast decline of CD4+ T-cells in pre-ART patients. It was also associated with increased ALT and AST enzyme levels in both HAART initiated and treatment naïve co-infected patients.

Anti-tuberculosis drug resistance among retreatment patients seen at St Peter Tuberculosis Specialized Hospital.

BACKGROUND: Resistance to first line anti-tuberculosis (TB) drugs is an increasing concern. Drug sensitivity of mycobacterial isolates from patients who failed treatment may indicate the potential sources of spread and the emerging patterns of resistance. OBJECTIVE: To determine the prevalence of resistance to the main anti TB drugs among re-treatment cases who had previously received loose drugs or the 3FDC regimen in the intensive phase. METHODS: Mycobacteria were isolated on Lowenstein-Jensen media from sputum of smear positive pulmonary TB patients who visited the St Peter's TB Specialized Hospital, a referral TB Hospital in Addis Ababa, for retreatment between December 2001 and October 2002. The susceptibility of isolates to rifampicin, isoniazid ethambutol and streptomycin was tested using the standard modified proportion method RESULT: Of the 84 Mycobacterium tuberculosis isolates, resistance to at least one drug was observed in 53.6% and 26.2% of the isolates were multi drug resistant (MDR). MDR was more frequent among patients who had previously been treated with the 3FDC regimen than among patients previously treated with loose drugs (p < 0.05). The proportion of strains resistant to rifampicin and ethambutol was significantly higher than in an earlier report from Addis Ababa. CONCLUSION: MDR is an emerging problem among re-treatment cases of pulmonary TB in Addis Ababa. The problem of drug resistance should be addressed by operational research on drug regimens, effectiveness and delivery.

Leishmania aethiopica: strain identification and characterization of superoxide dismutase-B genes.

This study was performed to characterize the genes that code for superoxide dismutase (SOD) in Leishmania aethiopica. It involved three main steps: specimen collection and parasite isolation, species identification, and molecular characterization of the SOD genes. Out of 20 skin slit specimens cultured and processed from suspected cutaneous leishmaniasis patients enrolled in the study, five (25%) were found to be positive for motile promastigotes. Isoenzyme electrophoresis and PCR-RFLP results confirmed that the isolates were L. aethiopica. Superoxide dismutase-B (SODB) genes were identified from L. aethiopica for the first time. Iron superoxide dismutase-B genes amplified from promastigotes of L. aethiopica (LaeFeSODB) were similar in size to the SODB genes of other Leishmania species. Nucleotide sequences of LaeFeSODB1 showed 95.4, 93.5, and 97.3% identity with L. donovani SODB1 (LdFeSODB1) L. major SODB1 (LmFeSODB1) and L. tropica SODB1 (LtrFeSODB1), respectively. Similarly, LaeFeSODB2 showed 95.9 and 94.1 and 97.6% identity with LdFeSODB2 and LmFeSODB2 and LtrFeSODB2, respectively. On the other hand, predicted amino acid sequence comparison indicated that LaeFeSODB1 had 91.3, 89.8, and 93.9% identity with LdFeSODB1, LmFeSODB1, and LtrFeSODB1, respectively. The difference in nucleic acid sequence of LaeFeSODB from that of LmFeSODB and LtrFeSODB can be utilized to develop specific molecular methods that help differentiate these species in places where there is an overlap in the distribution of these species. In addition, the data provide information about the situation of L. aethiopica with respect to SODB genes.