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Biomedical subjects

J M Chakaya

Publications and source records attributed to J M Chakaya.

13 recordsLinked to original sources

Susceptibility of healthcare workers in Kenya to hepatitis B: new strategies for facilitating vaccination uptake.

Hepatitis B virus (HBV) infection is preventable, yet many healthcare workers (HCWs) in resource-poor countries remain at risk. The aims of this study were to evaluate the susceptibility of HCWs in a Kenyan district to HBV infection, and the feasibility of expanding the Extended Programme of Immunization (EPI) for infants to incorporate hepatitis B vaccination of HCWs. HCWs in Thika district, Kenya were invited to complete an interviewer-administered questionnaire about their immunization status and exposure to blood or body fluids. Participants were asked to provide a blood sample to assess natural or vaccine-induced protection against HBV. All non-immune HCWs were offered hepatitis B vaccination. Thirty percent (168/554) of HCWs reported one or more needlestick injuries (NSIs) in the previous year, with an annual incidence of 0.97 NSIs/HCW/year. Only 12.8% (71/554) of HCWs had received vaccination previously and none had been screened for immunity or for hepatitis B surface antigen. In total, 407 staff provided blood samples; 41% were HBV core antibody, 4% expressed hepatitis B surface antibody from previous vaccination, and 55% were unprotected. Two hundred and twenty-two staff were eligible for vaccine delivered through the EPI infrastructure. Self-motivated uptake of a full course of vaccine was 92% in the smaller health centres and 44% in the district hospital. This study demonstrates the importance of hepatitis B vaccination of HCWs in parts of Africa where high exposure rates are combined with low levels of vaccine coverage. High rates of vaccination can be achieved using childhood immunization systems for the distribution of vaccine to HCWs.

Adult↗

Bronchoscopic study on aetiology of chronic cough in HIV-infected adults with negative sputum smears for Mycobacterium tuberculosis at Kenyatta National Hospital, Nairobi.

OBJECTIVE: To establish the aetiology of chronic cough in HIV-infected patients with negative sputum smears for Acid Fast Bacilli (AFB). DESIGN: A cross-sectional descriptive study. SETTING: Kenyatta National Hospital, a tertiary referral centre in Kenya SUBJECTS: Sixty five HIV-infected adults presenting with chronic cough and negative sputum smears for AFBs. RESULTS: Sixty-two patients were included in the final analysis. Aetiology of chronic cough was established in 42 (68%) patients. Pneumocystis jiroveci, bacterial pneumonia and Mycobacterium tuberculosis were diagnosed in 22 (35.5%), 17 (27.4%) and 14 (22.5%) patients respectively. Majority (98%) of patients with a diagnosis had multiple causes established in them. Ciprofloxacin had activity against 91% of the isolated organisms while Penicillin was active against 35% only. CONCLUSION: This study documents Pneumocystis jiroveci pneumonia as a common cause of morbidity in a subset of HIV infected patients with chronic cough and negative sputum smears for AFB in Kenya.

AIDS-Related Opportunistic Infections↗

Planning for PPM-DOTS implementation in urban slums in Kenya: knowledge, attitude and practices of private health care providers in Kibera slum, Nairobi.

SETTING: Kibera, the largest slum in Nairobi, Kenya. OBJECTIVE: To determine the tuberculosis (TB) knowledge, attitude and practices (KAP) of private health care providers (PHCPs) to identify their training needs and willingness to participate in a National Leprosy and Tuberculosis Control Programme (NLTP) guided TB control effort in the slum. DESIGN AND METHODOLOGY: A cross-sectional survey. The KAP of PHCPs was assessed using an interviewer administered questionnaire. RESULTS: Of 75 PHCPs interviewed, the majority (96.0%) were paramedics; 51 (77.1%) did not consider sputum smear microscopy crucial in patients presenting with prolonged cough or when a chest X-ray was suggestive of TB; of 29 (38.7%) who indicated familiarity with the drugs used in TB treatment, 20 (58.5%) would have chosen the NLTP-recommended regimens for the treatment of the various types of TB; 16 (21.3%) PHCPs indicated that they treated TB, six (37.5%) of whom were not familiar with anti-tuberculosis drug regimens. All the PHCPs referred TB suspects to the public sector for diagnosis. CONCLUSION: This study reveals a significant gap in TB knowledge among the PHCPs in Kibera slum. However, given appropriate training and supervision, there is potential for public-private mix for DOTS implementation in this setting.

Allied Health Personnel↗

Isolation of multidrug-resistant tuberculosis strains in patients from private and public health care facilities in Nairobi, Kenya.

SETTING: Health care facilities in Nairobi, Kenya. OBJECTIVE: To document the presence of multidrug-resistant tuberculosis (MDR-TB) strains in patients from Nairobi between September 1999 and October 2001. DESIGN: Descriptive study. RESULTS: Of the 983 referred patients who submitted sputum for culture and drug susceptibility testing (DST), 59% were males. Two hundred and nine (21.3%) patients had a positive culture, of whom 15.2% had a request for DST against isoniazid, rifampicin, streptomycin and ethambutol. Of these, 65 (43.6%) had an isolate resistant to one or more drugs, while 17 (11.4%) had MDR-TB. Ten (59.0%) cases were referred from public health care facilities while seven (41%) were from the private sector. Sixteen isolates were resistant to all four drugs. All MDR-TB cases but one were from Nairobi. CONCLUSION: The emergence of MDR-TB in Nairobi is a cause for concern. An outbreak would be catastrophic, creating not only increased morbidity and mortality but also a tremendous strain on already limited health care resources. Lack of policies for the treatment and management of MDR-TB and the unavailability of appropriate diagnostic facilities may increase its spread. Efforts to prevent outbreaks of MDR-TB should be emphasised.

Adult↗

Pneumocystis carinii pneumonia in HIV/AIDS patients at an urban district hospital in Kenya.

BACKGROUND: Pneumocystis carinii pneumonia has generally been regarded to be an uncommon opportunistic infection in HIV infected individuals in sub-Saharan Africa. The reason for this has not been clear but postulates included a lack of suitable pathogenic types in the African environment, diagnostic difficulties and the more commonly held belief that African HIV infected individuals were dying early from common non-opportunistic pathogens before severe degrees of immunosuppression occured. Recently a trend has emerged at the Mbagathi district hospital whereby an increasing number of HIV infected patients are empirically treated for Pneumocystis carinii pneumonia (PCP) based on clinical and radiological features. OBJECTIVE: To determine the prevalence of PCP and clinical outcomes of HIV infected patients presenting at the Mbagathi District Hospital, Nairobi with the presumptive diagnosis of PCP. SETTING: Mbagathi District Hospital, a 169-bed public hospital in Nairobi, Kenya. METHODS: Patients presenting with a sub-acute onset of cough and dyspnoea were eligible for the study if they were found to have bilateral pulmonary shadows and had negative sputum smears for AFBS. Consenting patients who had no contraindication to fiberoptic bronchoscopy had a clinical evaluation which was followed with a fiberoptic bronchoscopy procedure where bronchoalveolar lavage fluid (BALF) was obtained. BALF was examined for cysts of P. carinii using toluidine blue stain and immunofluorescent antibody test (IFAT). BALF was also processed for fungi, bacteria and mycobacteria using routine procedures. Standard treatment with high dose cotrimoxazole was offered to all patients who were then followed up until discharge from hospital or death whichever came first. RESULTS: Between June 1999 and August 2000 a total of 63 patients were referred for bronchoscopy. Of these four declined to undergo the fiberoptic bronchoscopy procedure, four died before the procedure could be done, one was judged too sick to undergo the procedure and three had been on cotrimoxazole for longer than five days. Thus 51 patients underwent bronchoscopy. Pneumocystis carinii stain was positive in 19 (37.2%) while death occured in 16 (31.4%) of the 51 patients. There were more deaths in those without PCP but this difference was not statistically significant (odds ratio 0.68 (95% CI 0.35-1.32; P=0.2). CONCLUSION: PCP was found to be common in HIV infected patients presenting with clinical and radiological features of the disease. The mortality rate for patients with a presumptive diagnosis of PCP is high. This study suggests that cotrimoxazole preventive therapy may be a useful intervention in symptomatic HIV infected patients in Kenya for the prevention of PCP and may avert deaths from this disease.

AIDS-Related Opportunistic Infections↗

Tuberculosis re-treatment outcomes within the public service in Nairobi, Kenya.

OBJECTIVES: This study was undertaken to describe treatment outcomes in patients started on a re-treatment drug regimen, assess the quality of follow up procedures and the adequacy of the currently advocated re-treatment drug regimen in Nairobi, Kenya. DESIGN: A retrospective study. SETTING: Mbagathi District Hospital (MDH), Nairobi, a public hospital that serves as the Tuberculosis (Tb) referral centre for Nairobi. MATERIALS AND METHODS: The Tb register at the MDH was used to identify patients who were on the re-treatment regimen for Tb. Case records for these patients were then retrieved. From these sources, information on age, sex, HIV status, previous and current tuberculosis disease and drug regimens, adherence to treatment and treatment outcomes, was obtained. Descriptive statistics was used to analyse the data. RESULTS: Of the total of 4702 patients registered at the MDH between 1996 and 1997, 593 (12.6%) were patients with either recurrent Tb, returning to treatment after default or had failed initial treatment. Of the 593 patients, case records were unavailable for 168 and 17 were children below the age of ten in whom the diagnosis of Tb was uncertain making a total of 185 patients who were excluded from the study. Of the remaining 408 patients, 77 (18.9%) were cured, 61 (15.0%) completed treatment without confirmation of cure, two (0.5%) defaulted, six (1.5%) died and 262 (64.2%) had no outcome information. There were no treatment failures. Treatment success defined as cure or treatment completion was achieved in 94.5% of the 146 patients in whom outcome data were available. HIV positive patients had a statistically significant poorer success rate (34/40, 85%) when compared with HIV negative patients (104/106, 94%), p=0.004. Mycobacterium tuberculosis culture and drug susceptibility testing, was not done. CONCLUSION: The high number of patients with no treatment outcome information at the MDH is worrying, as these patients may harbour drug resistant bacilli and reflects an inadequate follow up service for Tb re-treatment in Nairobi. However, where treatment outcomes could be assessed, the currently advocated re-treatment regimen achieved a high success rate. These observations point to an urgent need to improve Tb documentation and follow up procedures within the public service in Nairobi in order to forestall the emergence and spread of drug resistant Tb.

AIDS-Related Opportunistic Infections↗

Mycoplasma pneumoniae in children with pneumonia at Mbagathi District Hospital, Nairobi.

OBJECTIVE: To determine the prevalence of mycoplasma pneumoniae in nasopharyngeal aspirates of children under five years of age suffering from pneumonia. DESIGN: Cross-sectional survey. METHODS: Two primer sets targeting the genes coding for adhesion protein and 16S rRNA were used in PCR and M. pneumoniae specific antibodies were detected using commercial article agglutination kit. Microbiological investigations to isolate common acute respiratory infectious pathogens were also carried out. RESULTS: M. pneumoniae was detected in nasopharyngeal aspirates of 33.7% of the cases by PCR while serology was positive in only 4.1%. M. pneumoniae alone (single detection) was detected in 25% of the cases while 75% occurred with other acute respiratory infectious (ARI) pathogens. However, the results did not correlate with clinical outcome or the severity of pneumonia. No significant aetiology was found in 28% of the cases investigated, however microbiological investigations by culture revealed the presence of other aetiological agents as follows: Streptococcus pneumoniae (26%), Klebsiella pneumoniae (1%), Staphylococcus aureus (3%), E. coli (2%), parainfluenza viruses (5%), Salmonella(1%), adenovirus (4%), RSV (22%) and Candida spp(13%), Mycoplasma pneumoniae was more prevalent in children aged between six months and three years. Cases of M. pneumoniae PCR positive and S. pneumoniae exhibited similar seasonal distribution with peaks in May and September. However, there was no relationship between M. pneumoniae PCR positive and the severity of pneumonia. CONCLUSION: More investigation is required to establish the significance of atypical pathogens in respiratory infections in Kenya.

Age Distribution↗

Under-diagnosis of smear-positive pulmonary tuberculosis in Nairobi, Kenya.

SETTING: Nairobi City Council Chest Clinic, Nairobi, Kenya. OBJECTIVE: To determine if under-reading of sputum smears is a contributing factor in the disproportionate increase in smear-negative tuberculosis in Nairobi, Kenya. METHODOLOGY: Between October 1997 and November 1998, patients fulfilling the local programme definition of smear-negative presumed pulmonary tuberculosis were enrolled in the study. Two further sputum specimens were collected for examination in a research laboratory by fluorescence microscopy. RESULTS: Of 163 adult subjects enrolled, 55% were seropositive for the human immunodeficiency virus type 1 (HIV-1). One hundred subjects had had two pre-study sputum smears assessed before recruitment and produced two further sputum specimens for re-examination in the research laboratory; of these 19 (19%) were sputum smear-positive on re-examination and a further seven (7%) became smear-positive on second re-examination. CONCLUSIONS: Of those patients with smear-negative presumed pulmonary tuberculosis by the local programme definition, 26% were smear-positive when reexamined carefully with two repeat sputum smears. This suggests that the high rates of smear-negative tuberculosis being seen may in part be due to under-reading. This is probably as a result of the overwhelming burden of tuberculosis leading to over rapid and inaccurate sputum examination. Retraining of existing technicians and training of more technicians is likely to reduce underreading and increase the yield of smear-positive tuberculosis. This finding also stresses the need for regular quality assurance.

AIDS-Related Opportunistic Infections↗

Isoniazid preventive therapy for tuberculosis in HIV-1-infected adults: results of a randomized controlled trial.

OBJECTIVES: To determine the efficacy of isoniazid 300 mg daily for 6 months in the prevention of tuberculosis in HIV-1-infected adults and to determine whether tuberculosis preventive therapy prolongs survival in HIV-1-infected adults. DESIGN AND SETTING: Randomized, double-blind, placebo-controlled trial in Nairobi, Kenya. SUBJECTS: Six hundred and eighty-four HIV-1-infected adults. MAIN OUTCOME MEASURES: Development of tuberculosis and death. RESULTS: Three hundred and forty-two subjects received isoniazid and 342 received placebo. The median CD4 lymphocyte counts at enrolment were 322 and 346 x 10(6)/l in the isoniazid and placebo groups, respectively. The overall median follow-up from enrolment was 1.83 years (range, 0-3.4 years). The incidence of tuberculosis in the isoniazid group was 4.29 per 100 person-years (PY) of observation [95% confidence interval (CI) 2.78-6.33] and 3.86 per 100 PY of observation (95% CI, 2.45-5.79) in the placebo group, giving an adjusted rate ratio for isoniazid versus placebo of 0.92 (95% CI, 0.49-1.71). The adjusted rate ratio for tuberculosis for isoniazid versus placebo for tuberculin skin test (TST)-positive subjects was 0.60 (95% CI, 0.23-1.60) and for the TST-negative subjects, 1.23 (95% CI, 0.55-2.76). The overall adjusted mortality rate ratio for isoniazid versus placebo was 1.18 (95% CI, 0.79-1.75). Stratifying by TST reactivity gave an adjusted mortality rate ratio in those who were TST-positive of 0.33 (95% CI, 0.09-1.23) and for TST-negative subjects, 1.39 (95% CI, 0.90-2.12). CONCLUSIONS: Overall there was no statistically significant protective effect of daily isoniazid for 6 months in the prevention of tuberculosis. In the TST-positive subjects, where reactivation is likely to be the more important pathogenetic mechanism, there was some protection and some reduction in mortality, although this was not statistically significant. The small number of individuals in this subgroup made the power to detect a statistically significant difference in this subgroup low. Other influences that may have diluted the efficacy of isoniazid include a high rate of transmission of new infection and rapid progression to disease or insufficient duration of isoniazid in subjects with relatively advanced immunosuppression. The rate of drug resistance observed in subjects who received isoniazid and subsequently developed tuberculosis was low.

AIDS-Related Opportunistic Infections↗

Anti-tuberculous initial drug resistance of Mycobacterium tuberculosis in Kenya: a ten-year review.

Our experience at the Respiratory Diseases Research Unit (RDRU), over the last 10 years (1981-1990) on the initial drug resistance pattern, focusing on three drugs viz: isoniazid (H), streptomycin (S) and rifampicin (R) is presented. Records on all isolates of M. tuberculosis from one specimen of every newly diagnosed patient recruited countrywide between 1981-1990 were reviewed. We analyzed records of 6,514 isolates and found that total resistance to the three drugs had increased from 8.9% to 14.4%. Resistance to H alone increased from 6.8% to 10.2% while that of S alone from 0.8% to 1.8%. Resistance to R was between 0.1% and 0.3%. Generally, the increase in the resistance trend to both H and S was statistically significant (p = < 0.05 and 0.03, respectively). Although in our analysis we did not address the possible impact of HIV infection, we hope that these findings form a basis for evaluation of this and other possible factors on the emergence of anti-TB drug resistance in future studies.

Drug Resistance, Microbial↗