Low prevalence of methicillin resistant as determined by an automated identification system in two private hospitals in Nairobi, Kenya: a cross sectional study

Background: Staphylococcus aureus (S.aureus) is a major cause of both healthcare and community acquired infections. In developing countries, manual phenotypic tests are the mainstay for the identification of staphylococci with the tube and slide coagulase tests being relied upon as confirmatory tests for S. aureus. The subjectivity associated with interpretation of these tests may result in misidentification of coagulase negative staphylococci as S.aureus. Given that antibiotic resistance is more prevalent in CONS, this may result in over estimation of methicillin resistant S.aureus (MRSA) prevalence. Methods: A review of susceptibility data from all non-duplicate S.aureus isolates generated between March 2011 and May 2013 by the Vitek-2 (bioMérieux) automated system was performed by the authors. The data was generated routinely from processed clinical specimens submitted to the microbiology laboratories for culture and sensitivity at the Aga Khan University Hospital and Gertrude’s children’s hospital both situated in Nairobi. Results: Antimicrobial susceptibility data from a total of 731 non-duplicate S.aureus isolates was reviewed. Majority (79.2%) of the isolates were from pus swabs. Only 24 isolates were both cefoxitin and oxacillin resistant while 3 were resistant to oxacillin but susceptible to cefoxitin giving an overall MRSA prevalence of 3.7% (27/731). None of the isolates were resistant to mupirocin, linezolid, tigecycline, teicoplanin or vancomycin. Conclusion: The prevalence of MRSA in this study is much lower than what has been reported in most African countries. The significant change in antibiotic susceptibility compared to what has previously been reported in our hospital is most likely a consequence of the transition to an automated platform rather than a trend towards lower resistance rates

A ten-year review of neonatal bloodstream infections in a tertiary private hospital in Kenya

Introduction: Neonatal mortality in developing countries is usually due to an infectious cause. The gold standard of investigation in developing countries is a positive blood culture. It is important to know the aetiology of neonatal bloodstream infections so that empiric treatment can be effective. Methodology: We conducted a retrospective clinical audit over ten years between January 2000 until December 2009, looking at the aetiology of both early and late onset neonatal sepsis. We analysed data from 152 (23%) patient isolates out of 662 suspected cases of neonatal sepsis. Results: Our study revealed that Gram-positive organisms were the predominant cause of both early and late onset sepsis; the common isolates were Staphylococcus epidermidis (34%) and Staphylococcus aureus (27%). There were no isolates of group B Streptococcus. Candida species was isolated only in patients with late onset sepsis (6.9%). Bacterial isolates were relatively sensitive to the commonly used first- and second-line empiric antibiotics. Conclusion: Gram-positive organisms remain the major cause of neonatal bloodstream infections in our setup. The findings of this study will guide clinicians in prescribing the right empiric therapy in cases of suspected neonatal sepsis before the definitive culture results are obtained

Validation of c-reactive protein in the early diagnosis of neonatal sepsis in a tertiary care hospital in Kenya.

Objective: To evaluate utility of C-reactive protein (CRP) in the early diagnosis of neonatal sepsis in a tertiary care Newborn Unit in Kenya. Design: Cross-sectional study. Setting: Newborn Unit, Kenyatta National Hospital. Subjects: All neonates admitted to Newborn Unit, Kenyatta National Hospital during the study period with suspected sepsis based on specified clinical criteria. Results: Of the 310 infants, there were 83 episodes of proven sepsis and 94 episodes of probable sepsis. Using the standard CRP cut-off value of 5 mg/dl, a sensitivity of 95.2% in proven sepsis and 98.9% for probable septic episodes were noted. In proven sepsis, a specificity of 85.3%, positive predictive value of 80.6%, and a negative predictive value of 96.5% were noted. In probable sepsis, a specificity of 83.3%, positive predictive value of 80.9% and a negative predictive value of 99.1% were noted. The overall accuracy in proven sepsis was 96.5%, and in probable sepsis was noted to be 99.1%. Sub-analysis showed a lower positive predictive value (61.5%) for early onset sepsis compared to 93% for late onset sepsis. Repeat CRP tests were done in 33 babies. Twenty two of the 29 with proven/probable infection had a ten-fold increase in CRP levels, but levels were noted to be low or reducing in seven (24.1%) babies showing signs of improvement clinically. Using a receiver operator characteristic curve, the optimal cut-off point for CRP was found to be 5 mg/dl. Conclusions: Serum CRP is an accurate indicator of neonatal sepsis, with high sensitivity, specificity and predictive values, at the standard cut-off of 5. CRP is a better screening test for late-onset than early-onset neonatal sepsis. The standard recommended CRP cut -off point of 5 is appropriate for local use

Comparison of Clinical Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing guidelines for the interpretation of antibiotic susceptibility at a University teaching hospital in Nairobi, Kenya: a cross-sectional study

Background: The Clinical Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines are the most popular breakpoint guidelines used in antimicrobial susceptibility testing worldwide. The EUCAST guidelines are freely available to users while CLSI is available for non-members as a package of three documents for US $500 annually. This is prohibitive for clinical microbiology laboratories in resource poor settings. We set out to compare antibiotic susceptibility determined by the two guidelines to determine whether adoption of EUCAST guidelines would significantly affect our susceptibility patterns. Methods: We reviewed minimum inhibitory concentrations (MIC) of various antibiotics routinely reported for Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) isolates from an automated microbiology identification system (VITEK-2) at the Aga Khan University Hospital Nairobi’s Pathology department. These MICs were then analyzed using both CLSI 2015 and EUCAST 2015 guidelines and classified as resistant, intermediate or susceptible. We compared the susceptibility and agreement between the CLSI and EUCAST categorizations. Results: Susceptibility data from a total of 5165 E. coli, 1103 S. aureus and 532 P. aeruginosa isolates were included. The concordance rates of the two guidelines for E. coli, S. aureus and P. aeruginosa ranged from 78.2 to 100 %, 94.6 to 100 % and 89.1 to 95.5 % respectively. The kappa statistics for E. coli MICs revealed perfect agreement between CLSI and EUCAST for cefotaxime, ceftriaxone and trimethoprim–sulfamethoxazole, almost perfect agreement for ampicillin, ciprofloxacin, cefuroxime, gentamicin and ceftazidime, substantial agreement for meropenem, moderate agreement for cefepime and amoxicillin-clavulanate, fair agreement for nitrofurantoin and poor agreement for amikacin. For S. aureus the kappa statistics revealed perfect agreement for penicillin, trimethoprim–sulfamethoxazole, levofloxacin, oxacillin, linezolid and vancomycin, almost perfect agreement for clindamycin, erythromycin and tetracycline and moderate agreement for gentamicin. For P. aeruginosa the kappa analysis revealed moderate to almost perfect agreement for all the anti-pseudomonal antibiotics. Conclusion: The results show comparable antibiotic susceptibility patterns between CLSI and EUCAST breakpoints. Given that EUCAST guidelines are freely available, it makes it easier for laboratories in resource poor settings to have an updated and readily available reference for interpreting antibiotic susceptibilities

Resistance patterns of Mycobacterium tuberculosis isolates from pulmonary tuberculosis patients in Nairobi

Introduction: In Kenya, which ranks thirteenth of 27 high tuberculosis burden countries, diagnosis is based on Ziehl-Neelsen staining alone and patients are treated without information on sensitivity patterns. This study aimed to determine resistance patterns of Mycobacterium tuberculosis isolated from pulmonary samples. Methodology: Pulmonary tuberculosis patients in Nairobi were randomly sampled after informed consent and recruited into the study using a structured questionnaire. Specimens were cultured in liquid and solid media, and drug susceptibility tests were performed for first-line drugs including (isoniazid, rifampin, streptomycin, ethambutol and pyrazinamide). Results: Eighty-six (30%) of 286 isolates were resistant to at least one of five antibiotics tested. Thirty-seven (30.2%) isolates were resistant to isoniazid; 15 (11.6%) to streptomycin; 13 (4.5%) to ethambutol; four (1.4%) to rifampin ; and 30 (10.4%) to pyrazinamide. Double resistance was seen as follows: four (1.4%) isolates were resistant to both isoniazid and pyrazinamide; four (1.4%) to streptomycin and isoniazid; and one (0.3%) to rifampin and streptomycin. Two isolates (0.7%) were multidrug resistant, and one was triple resistant with an additional resistance to ethambutol. Results also showed 88.7% of patients were below the age of 40 years, while 26.3% were HIV positive. The majority of the patients (66.5%) were unemployed or self-employed in small businesses, with 79.4% earning less than 100 USD per month. Conclusion: The high resistance observed in isoniazid, which is a first-line drug, could result in an increase in multidrug resistance unless control programs are strengthened. Poverty should be addressed to reduce infection rates

Spectrum of Microbial Diseases and Resistance Patterns at a Private Teaching Hospital in Kenya: Implications for Clinical Practice

Background: Accurate local prevalence of microbial diseases and microbial resistance data are vital for optimal treatment of patients. However, there are few reports of these data from developing countries, especially from sub-Saharan Africa. The status of Aga Khan University Hospital Nairobi as an internationally accredited hospital and a laboratory with an electronic medical record system has made it possible to analyze local prevalence and antimicrobial susceptibility data and compare it with other published data. Methods: We have analyzed the spectrum of microbial agents and resistance patterns seen at a 300 bed tertiary private teaching hospital in Kenya using microbial identity and susceptibility data captured in hospital and laboratory electronic records between 2010 and 2014. Results: For blood isolates, we used culture collection within the first three days of hospitalization as a surrogate for community onset, and within that group, Escherichia coli was the most common, followed by Staphylococcus aureus. In contrast, Candida spp. and Klebsiella pneumoniae were the most common hospital onset causes of bloodstream infection. Antimicrobial resistance rates for the most commonly isolated Gram negative organisms was higher than many recent reports from Europe and North America. In contrast, Gram positive resistance rates were quite low, with 94% of S. aureus being susceptible to oxacillin and only rare isolates of vancomycin-resistant enterococci. Conclusions: The current report demonstrates high rates of antimicrobial resistance in Gram negative organisms, even in outpatients with urinary tract infections. On the other hand, rates of resistance in Gram positive organisms, notably S. aureus, are remarkably low. A better understanding of the reasons for these trends may contribute to ongoing efforts to combat antimicrobial resistance globally

Helicobacter pylori: prevalence and antibiotic susceptibility among Kenyans

Background. Helicobacter pylori infection in Kenya is staggeringly high. Evidence links infection of the gastric mucosa by H. pylori with subsequent development of gastric pathologies. Aim. We investigated the prevalence of H. pylori in dyspeptic patients, its relationship with gastric pathologies, and associated antibiotic susceptibility profiles, and compared two media to find the appropriate medium that enhances growth and expedites culture and isolation. Methods. Rapid urease and histological tests were used to screen for H. pylori. Culture was performed to test sensitivity and evaluate media. Selective and nutritional supplements were added to culture media (Colombia blood agar and brainheart infusion agar) for growth enhancement. E-test strips for metronidazole, amoxicillin and clarithromycin were used for susceptibility testing. Results. The prevalence of H. pylori infection in children was 73.3%, and 54.8% in adults. All the H. pylori investigated in this study were largely sensitive to clarithromycin (100%, minimum inhibiting concentration (MIC)μg/ml), amoxicillin (100%, MICμg/ml) and metronidazole (95.4%, MICμg/ml). There was, however, occasional resistance to metronidazole (4.6%, MIC \u3e8 μg/ml). Both Colombia blood and brain-heart infusion agar, with the supplements, effectively supported H. pylori growth. Growth was achieved in an average of 36 hours for primary isolations and 24 hours for subcultures. Conclusion. The media described here reduce the time required to culture and isolate bacteria and perform susceptibility testing. Despite the high prevalence of H. pylori infection, the associated pathology is low and does not parallel H. pylori prevalence in the population

Trends in salmonella enteric serovar typhi in Nairobi, Kenya from 2004 to 2006

Background: Typhoid fever is a global health problem. The World Health Organization (WHO) estimates that the current annual global burden of typhoid is approximately 22 million new cases, 5% of which are fatal. Methodology: To assess the trends in antibiotic resistance in 100 Salmonella enterica serovar Typhi strains were isolated from the blood of patients in Nairobi, Kenya, from 2004 to 2006. All isolates were tested against ampicilin, chloramphenic, nalidixic acid, ciprofloxacin, cotrimoxazole, cefuroxime, cefriaxone, amoxycillin/clavulanic acid, tetracycline and gentamycin. Susceptibility and resistance were determined using MIC and disk diffusion tests. Results: From 2004 to 2006 a total of 100 strains were studied; 70% of the isolates were multidrug resistant (MDR) while 15% of the isolates were sensitive to all drugs tested. Of 13 isolates that were resistant to ciprofloxacin and nalidixic acid by disk diffusion, 11 had an MIC of 0. 25 μg/ml while two isolates had an MIC of 1.00 μg,/ml. Resistance in ampicillin decreased from 88% in 2004 to 64% in 2005; this increased to 76% in 2006. Similar trends were observed for four other antibiotics tested. Conclusion: The prescription of first-line antibiotics used in the treatment of S. Typhi should be stopped temporarily. Drugs such as cipfloxacin would be useful in the treatment of typhoid caused by MDR S. Typhi. There is need to monitor the resistance in flouroquinolones as resistance to these drugs has been observed and they are the current drugs used to treat typhoid

Prevalence of genital chlamydia infection in urban women of reproductive age, Nairobi, Kenya

Background: Chlamydia trachomatis is one of the major causes of sexually transmitted infections throughout the world. Most infections are asymptomatic and remain undetected. Burden of disease in the Kenyan population is not well characterised. This study was done to define the prevalence of genital Chlamydia infection in a representative female population. Findings: A cross-sectional study design was employed. All women attending out-patient clinics (antenatal, gynaecology, family planning) and accident and emergency departments at two study sites over a five month period were invited to consent to completion of a questionnaire and vaginal swab collection. A rapid point-of-care immunoassay based test was performed on the swabs. Women who tested positive for Chlamydia were offered treatment, together with their partner(s), and advised to come for a follow-up test. A total of 300 women were tested. The prevalence of genital Chlamydia trachomatis was found to be 6% (95% CI 3.31% – 8.69%). The prevalence was higher in women who represented a higher socioeconomic level, but this difference was not significant (p=0.061). Use of vaginal swabs was observed to be a more acceptable form of sample collection. Conclusion: The prevalence of genital Chlamydia is significant in our female population. There is a justifiable need to institute opportunistic screening programs to reduce the burden of this disease. Rapid and low cost point-of-care testing as a potential component of sexually transmitted infection (STI) screening can be utilised

Prevalence of genital chlamydia infection in urban women of reproductive age, Nairobi, Kenya

Background: Chlamydia trachomatis is one of the major causes of sexually transmitted infections throughout the world. Most infections are asymptomatic and remain undetected. Burden of disease in the Kenyan population is not well characterised. This study was done to define the prevalence of genital Chlamydia infection in a representative female population. Findings: A cross-sectional study design was employed. All women attending out-patient clinics (antenatal, gynaecology, family planning) and accident and emergency departments at two study sites over a five month period were invited to consent to completion of a questionnaire and vaginal swab collection. A rapid point-of-care immunoassay based test was performed on the swabs. Women who tested positive for Chlamydia were offered treatment, together with their partner(s), and advised to come for a follow-up test. A total of 300 women were tested. The prevalence of genital Chlamydia trachomatis was found to be 6% (95% CI 3.31% - 8.69%). The prevalence was higher in women who represented a higher socioeconomic level, but this difference was not significant (p=0.061). Use of vaginal swabs was observed to be a more acceptable form of sample collection. Conclusion: The prevalence of genital Chlamydia is significant in our female population. There is a justifiable need to institute opportunistic screening programs to reduce the burden of this disease. Rapid and low cost point-of-care testing as a potential component of sexually transmitted infection (STI) screening can be utilised.Publisher PDFPeer reviewe