Plasmid Borne Resistance in Klebsiella Isolates from Kenyatta National Hospital, Nairobi, Kenya

Eighty six Klebsiella isolates from Kenyatta National Hospital and the Centre for Microbiology, Kenya Medical Research Institute, Nairobi were screened forresistance to commonly prescribed antimicrobial agents and for their plasmidcontent. Plasmids were transferred into Esherichia coli K-12 and resultingtransconjugants screened for resistance to the antimicrobial agents used onKlebsiella donors and for their plasmid content. Plasmids from the Klebsiellaisolates were also transformed into Eschericia coli and transformants analyzedfor resistance and plasmid content. Endonuclease restriction mapping was done to characterize the plasmids from Klebsiella isolates and their Eschericia coli transformants. Resistance was found to be plasmid borne and transmissible

Ziehl-Neelsen microscopy in the diagnosis of tuberculosis in settings of high human immunodeficiency virus prevalence

Objective: To determine the accuracy of Ziehl-Neelsen microscopy in the diagnosis of TB in setings of high HIV prevalence.Design: Cross-sectional descriptive study.Setting: Hospitals serving areas of high human immunodeficiency virus prevalence in western Kenya. The study was conducted between September 2007 and September 2009.Results: In total, 341/872 (39.1%) of the TB suspects were positive in ZN, 53.1% (181/341) of them culture positive. Only 3.8% (20/531) of the ZN smear negatives were culture positive. Of the 695 suspects evaluated for both Mycobacterium and HIV infection, 255 (36.7%) were ZN smear positive, 42.7% of them HIV positive. Out of the 440 ZN smear negatives, 37% were HIV positive. Similarly, 168 suspects were culture positive, 46.4% of them HIV positive. The HIV infection did not significantly reduce ZN smear positivity rate (P = 0.42) and culture sensitivity (P = 0.09). The ZN sensitivity and specificity were 88.1% and 79.7%, respectively. The predictive values were 58.0 (PPV), and 95.5% (NPV), respectively. However, the area under the ROC curve was 0.84, with 95% CI between 0.80-0.87 and P< 0.001). The ZN smear microscopy had a lesser ability to distinguish between TB and non-TB cases compared to culture.Conclusion: ZN microscopy causes a significant over-diagnosis of TB in settings of high HIV/AIDS prevalence. There is need for further studies on this subject taking into consideration the various confounding factors

Misdiagnosis and clinical significance of non-tuberculous mycobacteria in Western Kenya in the era of human immunodeficiency virus epidemic

Objectives: To determine and document the role of non-tuberculous mycobacteria (NTM) in TB-like disease morbidity and demonstrate the confusion they cause in the diagnosis of TB in western Kenya.Design: A cross-sectional study.Setting: One provincial and nine District hospitals in western Kenya.Subjects: Tuberculosis suspects.Interventions: Sputa from 872 tuberculosis suspects underwent microscopy and culture on solid and liquid media. The growth was identified using the Hain’s GenoType® Mycobacterium CM and GenoType® Mycobacterium AS kits. Consenting clients were screened for HIV infection using Trinity Biotech Uni-GoldTM test and positive cases were confirmed with the enzyme linked immunosorbent assay. A questionnaire was used to obtain demographic data.Main outcome measures: ZN smear positivity / negativity; Culture positivity or negativity; Mycobacterium species isolates (tuberculous or non-tuberculous); HIV status.                                                      Results: Sputa from 39.1% (341/872) of the participants were ZN smear positive, of these 53.1% (181/341) were culture positive. Only 3.8% (20/531) of the ZN smear negatives were culture positive. In total 41.4% (361/872) participants were infected with mycobacteria, of which 44.3% (160/361) were culture negative and 55.7% (201/361) were culture positive. The culture positives yielded 92.5% M. tuberculosis complexand 7.5% NTM. The overall prevalence of the NTM disease was 1.72% (15/872).                                                                            Conclusion: A low prevalence of NT M pulmonary disease in western Kenya is reported in this study, but some the NTM disease cases could have been misdiagnosed as TB cases

HIV co-infection with tuberculous and non-tuberculous mycobacteria in western Kenya: challenges in the diagnosis and management

Background: Tuberculosis (TB) and HIV co-infections have a global prevalence with devastating morbidity and massive mortality, Sub-Saharan Africa being the worst hit.Objectives: To evaluate the prevalence of TB-HIV co-infection and demonstrate the confusion caused by NTM and HIV/AIDS co-infection in TB diagnosis and treatment in western Kenya.Methods: In a cross-sectional study carried out at 10 hospitals in western Kenya, sputa from consenting 872 TB suspects underwent microscopy, and culture on Lowenstein-Jensen and Mycobacteria Growth Index Tube media. Isolates were identified using the Hain’s GenoType® Mycobacterium CM and GenoType® Mycobacterium AS kits. A total of 695 participants were screened for HIV using Uni-GoldTM test and positives confirmed with the enzyme linked immunosorbent assay.Results: A total of 346 (39.7%) participants were diagnosed with TB. Out of the 346 TB cases, 263 (76%) were tested for HIV infection and 110 (41.8%) of these were sero-positive (co-infected). The female to male TB-HIV co-infection prevalence ratio (PR) was 1.35. This study reports isolation of non-tuberculous mycobacteria from TB suspects at a rate of 1.7%.Conclusion: A high TB-HIV co-infection rate was observed in this study. The NTM disease could be misdiagnosed and treated as TB in western Kenya.Key words: Tuberculosis, HIV co-infection, high prevalence, TB diagnosi

The Presentation and Outcome of Hiv-Related Disease in Nairobi

The range of clinical presentations of HIV-related disease in Africa has not been adequately described, despite the fact that many hospitals have to rely heavily on clinical diagnosis. Six hundred adult medical patients seen in the Casualty Department of the main Government hospital in Nairobi were enrolled in a study of the presentation and outcome of HIV-related disease: 506 of these patients were admitted, of whom 19 per cent (95) were HIV seropositive. The remaining 94 were dealt with as outpatients: 11 percent (10) of these were seropositive. A history of prior treatment for sexually transmitted disease and, if male, being uncircumcised, were associated with being seropositive. Three presentations were strongly associated with HIV infection: acute fever with no focus except the gastrointestinal tract (enteric fever-like illness), acute cough with fever (community-acquired pneumonia) and chronic diarrhoea with wasting. The WHO clinical case definition (CCD) for AIDS missed a substantial amount of HIV-related morbidity (sensitivity 39 per cent) and misidentified many seronegative patients (positive predictive value 59 per cent). In comparison with the Centers for Disease Control surveillance definition for AIDS, the CCD was specific (91 per cent) and sensitive (79 per cent) but only had a positive predictive values of 30 per cent: the CCD may therefore be a poor surveillance tool for AIDS. Seropositive patients were much more likely to die than were seronegative patients (39 per cent vs. 15 per cent mortality). Enteric fever-like illness was the presentation which most commonly proved fatal. A wider spectrum of disease is associated with underlying HIV immunosuppression than has previously been described in Africa

Extrapulmonary and Disseminated Tuberculosis in Hiv-1-Seropositive Patients Presenting to the Acute Medical-Services in Nairobi

We studied 506 consecutive adult acute medical admissions to hospital in Nairobi; 95 (18.8%) were seropositive for HIV-1, and 43 new cases of active tuberculosis (TB) were identified. TB was clearly associated with HIV infection, occurring in 17.9% of seropositive patients compared with 6.3% of seronegatives [odds ratio (OR) 3.2; 95% confidence limits (CL) 1.6-6.5]. Extrapulmonary disease was more common in seropositive than seronegative TB patients (nine out of 17 versus five out of 26; OR 4.7; 95% CL 1.01-23.6); this accounted for most of the excess cases of TB seen in seropositive patients. Mycobacteraemia was demonstrated in two of eight seropositive TB patients but in none of 11 seronegative TB patients. No atypical mycobacteria were isolated. The World Health Organization (WHO) clinical case definition for African AIDS did not discriminate well between seropositive and seronegative TB cases. Five out of seven seropositive women with active tuberculosis had delivered children in the preceding 6 months and were lactating, compared with only one out of eight seronegative tuberculous women. An association between recent childbirth, HIV immunosuppression and the development of TB is suggested