Carriage of potentially pathogenic Escherichia coli in chickens.

DNA-DNA hybridization, cultured cell lines, and transmission electron microscopy were used to study pathogenicity traits of 64 Escherichia coli isolated from apparently healthy chickens from 18 small-scale farms in Thika District, Kenya. A total of 39 (60.9%) isolates hybridized with the eae gene probe for enteropathogenic E. coli (EPEC) whereas another 16 (25%) hybridized with the lt and st gene probes and were categorized as enterotoxigenic E. coli. Electron microscopic examination of the eae probe-positive E. coli cultures with the HT-2919A cell line confirmed that they were able to attach intimately and produced effacement typical of EPEC. In addition, negative stain electron microscopy showed that the EPEC strains produced pili that have previously been associated with increased virulence of E. coli infections in chickens. This study has also demonstrated that apparently healthy chickens may carry enteropathogenic E. coli strains.

Respiratory tract infection in HIV-1-infected adults in Nairobi, Kenya: evaluation of risk factors and the world health organization treatment algorithm.

To evaluate the WHO (World Health Organization) algorithm for management of respiratory tract infection (RTI) in HIV-1-infected adults and determine risk factors associated with RTI, we enrolled a cohort of 380 HIV-1-seropositive adults prospectively followed for incident RTI at an outpatient clinic in Nairobi, Kenya. RTI was diagnosed when patients presented with history of worsening or persistent cough. Patients were treated with ampicillin, or antituberculosis therapy when clinically indicated, as first-line therapy and with trimethoprim/sulfamethoxazole as second-line therapy. Five hundred ninety-seven episodes of RTI were diagnosed: 177 of pneumonia and 420 of bronchitis. The WHO RTI algorithm was used for 401 (95%) episodes of bronchitis and 151 (85%) episodes of pneumonia (p <.001). Three percent of bronchitis cases versus 32% of pneumonia cases failed to respond to first-or second-line treatment (p <.0001). Being widowed (adjusted odds ratio [OR] = 2.1, 95% confidence interval [CI]: 1.0-4.4), less than 8 years of education (adjusted OR = 2.5, CI: 1.5 - 4.1), and CD4 count < 200 cells/microl (adjusted OR = 2.4, CI: 1.4-3.9) were risk factors for pneumonia. A high percentage of patients (32%) with pneumonia required a change in treatment from that recommended by the WHO guidelines. Randomized trials should be performed to determine more appropriate treatment strategies in HIV-1-infected individuals.

Trends in bloodstream infections among human immunodeficiency virus-infected adults admitted to a hospital in Nairobi, Kenya, during the last decade.

Bloodstream infections are a frequent complication in human immunodeficiency virus (HIV)-infected adults in Africa and usually associated with a poor prognosis. We evaluated bloodstream infections across a decade in 3 prospective cross-sectional surveys of consecutive medical admissions to the Kenyatta National Hospital, Nairobi, Kenya. Participants received standard clinical care throughout. In 1988-1989, 29.5% (28 of 95) of HIV-positive patients had bloodstream infections, compared with 31.9% (46 of 144) in 1992 and 21.3% (43 of 197) in 1997. Bacteremia and mycobacteremia were significantly associated with HIV infection. Infections with Mycobacterium tuberculosis, non-typhi species of Salmonella (NTS), and Streptococcus pneumoniae predominated. Fungemia exclusively due to Cryptococcus neoformans was uncommon. Clinical features at presentation remained similar. Significant improvements in the survival rate were recorded among patients with NTS bacteremia (20%-83%; P<.01) and mycobacteremia (0%-73%; P<.01). Standard clinical management can improve outcomes in resource-poor settings.

Analysis of Salmonella enterica serotype Typhimurium by phage typing, antimicrobial susceptibility and pulsed-field gel electrophoresis.

Three typing methods commonly used for bacteria--phage typing, antimicrobial susceptibility and pulsed-field gel electrophoresis (PFGE)- were used to characterise 64 Salmonella enterica serotype Typhimurium isolates from individual adult patients from Nairobi, Kenya. The isolates encompassed 11 definitive phage types (DTs), which fell into eight PFGE clusters; 31.3% of isolates were either untypable or reacted nonspecifically with the phages used for typing and 26.6% were of DT 56. Plasmids of c. 100 kb were responsible for self-transferable multiresistance among the isolates. Analysis by PFGE and phage type demonstrated that multiresistant Typhimurium strains causing diarrhoea and invasive disease were multiclonal.

Genotype analysis of Escherichia coli strains isolated from children and chickens living in close contact.

Escherichia coli isolates from rectal swabs from 62 chickens and stools from 42 children living in close contact with chickens on the same farms in Kiambu district, Kenya, were compared for their genetic relatedness. Antibiotic susceptibility profiles broadly categorized isolates from the children and from the chickens into two separate clusters: the majority (144; 85.5%) of the E. coli isolates from children were multidrug resistant, while the majority (216; 87.1%) of the E. coli isolates from chickens were either fully susceptible or resistant only to tetracycline. Sixty- and 100- to 110-MDA plasmids were found to encode the transferable resistance to co-trimoxazole and tetracycline. HindIII restriction endonuclease digestion of the 60- and 100- to 110-MDA plasmids produced four distinct patterns for isolates from children and three distinct patterns for isolates from chickens. XbaI digestion of genomic DNA followed by pulsed-field gel electrophoresis (PFGE) analysis produced 14 distinct clusters. There were six distinct PFGE clusters among the isolates from children, while among the isolates from chickens there were seven distinct clusters. Only one PFGE cluster contained isolates from both children and chickens, with the isolates displaying an approximately 60% coefficient of similarity. This study showed that although several different genotypes of E. coli were isolated from children and chickens from the same farms, the E. coli strains from these two sources were distinct.

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.

Recent transmission of tuberculosis in a cohort of HIV-1-infected female sex workers in Nairobi, Kenya.

OBJECTIVES: To describe the epidemiological and clinical characteristics of HIV-related tuberculosis in a female cohort, and to investigate the relative importance of recently transmitted infection and reactivation in the pathogenesis of adult HIV-related tuberculosis. DESIGN: Members of an established cohort of female sex workers in Nairobi were enrolled in a prospective study. Women were followed up regularly and seen on demand when sick. METHODS: Between October 1989 and September 1992 we followed 587 HIV-infected and 132 HIV-seronegative women. Standard protocols were used to investigate common presentations. Cases of tuberculosis were identified clinically or by culture. All available Mycobacterium tuberculosis strains underwent DNA fingerprint analysis. RESULTS: Forty-nine incident and four recurrent episodes of tuberculosis were seen in HIV-infected women; no disease was seen in seronegative sex workers (P = 0.0003). The overall incidence rate of tuberculosis was 34.5 per 1000 person-years amongst HIV-infected participants. In purified protein derivative (PPD) skin test-positive women the rate was 66.7 per 1000 person-years versus 18.1 per 1000 person-years in PPD-negative women. Twenty incident cases (41%) were clinically compatible with primary disease. DNA fingerprint analysis of strains from 32 incident cases identified two clusters comprising two and nine patients; allowing for index cases, 10 patients (28%) may have had recently transmitted disease. Three out of 10 (30%) patients who were initially PPD skin test-negative became PPD-positive. Taken together, 26 incident cases (53%) may have been recently infected. DNA fingerprint analysis also identified two (50%) of the four recurrent tuberculosis episodes as reinfection. CONCLUSIONS: Substantial recent transmission of tuberculosis appears to be occurring in Nairobi amongst HIV-infected sex workers. It may be incorrect to assume in other regions of high tuberculosis transmission that active HIV-related tuberculosis usually represents reactivation of latent infection.

PIP: A 3-year (1989-92) prospective study of 587 HIV-positive and 132 HIV-negative commercial sex workers in Nairobi, Kenya, revealed substantial recent transmission of tuberculosis in the HIV-infected group. The cohort was enrolled at a community clinic that provides counseling, sexually transmitted disease services, and free condoms. In HIV-positive women, 49 incident and 4 recurrent episodes of tuberculosis were diagnosed during the study period; there were no tuberculosis cases among HIV-negative women. The overall incidence rate of tuberculosis was 34.5/1000 person-years among HIV-positive women. 20 incident cases (41%) met the clinical case definition of primary disease. DNA fingerprint analysis of strains from 32 incident cases suggested 10 women (28%) may have had recently transmitted disease. 3 of 10 women who were initially purified protein derivative (PPD) skin test-negative became PPD-positive. Clinical presentation, tuberculin skin testing, and strain clustering data all independently suggested that substantial Mycobacterium tuberculosis transmission was occurring in HIV-infected prostitutes during the study period. As many as 26 (53%) of the 49 patients with incident disease may have recently acquired tuberculosis and DNA fingerprint analysis identified 2 (50%) of the 4 recurrent tuberculosis episodes as reinfection. These findings challenge the assumption that tuberculosis in HIV-infected individuals represents reactivation of latent endogenous infection.

Plasmid diversity of multi-drug-resistant Escherichia coli isolated from children with diarrhoea in a poultry-farming area in Kenya.

Biotin-labelled DNA probes and restriction-endonuclease digestion (RED) with HindIII were used to study the diversity of resistance plasmids (R-plasmids) from 414 Escherichia coli isolates: 168 from children living in close contact with antibiotic-fed poultry and 246 from the chickens. Full sensitivity to all 10 antimicrobials tested was more common in the isolates from poultry than in those from the children (36.2% v. 9.5%; P < 0.001). Multi-drug resistance, to at least two of the antimicrobials, was relatively common in the isolates from the children (85.5% v. 26.00%; P < 0.001). Overall, 31% of the poultry isolates were resistant to tetracycline alone. Resistance to amoxycillin was due to production of TEM-1 (89%) and TEM-2 (11%). In > 71% of the isolates from children and 79% of those from poultry, resistance was encoded on a 100-110-kb transferable plasmid belonging to incompatibility group FII. However, RED patterns of R-plasmids from the two groups of isolates were highly diverse and not indicative of any close relatedness. This difference in patterns and in the levels of multi-drug resistance indicate that the isolates from the children and those from the poultry represent two distinct pools of resistance plasmids.

Molecular typing of multi-drug resistant Shigella dysenteriae type 1 by plasmid analysis and pulsed-field gel electrophoresis.

Recently, an outbreak of dysentery due to multi-drug resistant Shigella dysenteriae type 1 strains was reported along the coastal area of Kenya and shortly thereafter another outbreak appeared in the outskirts of Nairobi. We analysed 22 multi-drug resistant S. Dysenteriae type 1 strains isolated from cases in the latter outbreak using plasmid deoxyribonucleic acid (DNA) profiles and pulse-field gel electrophoresis of genomic DNA. All isolates were resistant to commonly available drugs including ampicillin, trimethoprim, sulphamethoxazole, chloramphenicol, tetracycline and streptomycin with minimum inhibitory concentrations > 64 micrograms/mL, but were fully sensitive to gentamicin. Only 2 strains were resistant to nalidixic acid. Analysis of plasmid DNA and genomic DNA revealed that all 22 strains were clonally related. It is likely that the present outbreak was related to that on the coast, as suggested by the similarity in drug susceptibility data. The drug susceptibility and molecular epidemiological data provide a useful baseline for future monitoring of epidemic and endemic S. dysenteriae activity in East Africa.

No increased prevalence of adrenocortical insufficiency in human immunodeficiency virus-associated tuberculosis.

SETTING: Acute medical wards, Kenyatta National Hospital, Nairobi, Kenya. OBJECTIVE: To determine the prevalence of adrenocortical insufficiency in human immunodeficiency virus (HIV)-1 infected and non-infected patients with tuberculosis. DESIGN: One hundred and seventy-four patients with proven tuberculosis (90 HIV-1 positive and 84 HIV-1 negative) were assessed for adrenocortical insufficiency with a 30 min synacthen stimulation test. RESULTS: Fifty-one percent of those with pulmonary tuberculosis and 56% of those with extra-pulmonary tuberculosis had a subnormal cortisol response. However there was no statistically significant difference between the HIV-1 infected and non-infected patients in either group. CONCLUSION: While an impaired cortisol response is common in tuberculosis, it is no more prevalent in HIV-1 infected patients than non-infected patients with tuberculosis.

Multi-drug resistant non-typhi salmonellae in Kenya.

Two methods of plasmid characterization, restriction digest patterns and incompatibility grouping, were used to study self-transmissible multi-drug resistance among non-typhi salmonellae (NTS). Resistance to ampicillin and other commonly applied beta-lactams was evaluated by iso-electric focusing and disc inactivation. Of the NTS isolated from blood, 75% were Salmonella typhimurium but those included several different phage types. Over 47% of isolates were resistant to three or more of the readily available drugs including ampicillin, cefuroxime, chloramphenicol, co-trimoxazole, streptomycin and tetracycline. Self-transferable resistance plasmids (c. 100 kb) were essentially of incompatibility group incFIIA, but their restriction fragment patterns revealed a diversity in relatedness. More than half of parent strains and their transconjugants produced beta-lactamases which co-electrophoresed with TEM-1 and OXA-1. This study has observed a disturbingly high prevalence of transmissible multi-drug resistance among NTS which are an important cause of morbidity in HIV-1 seropositive individuals.

Microbiology of HIV associated bacteraemia and diarrhoea in adults from Nairobi, Kenya.

We undertook a retrospective descriptive comparison of the spectrum of pathogens responsible for bacteraemia and diarrhoea in HIV antibody positive and negative patients over 4 years (1988-92), in Nairobi, Kenya. The study population was recruited from primary to tertiary centres of clinical care and consisted of 2858 adults (15 years or older). There were 415 significant blood culture isolates, 192 from 1785 HIV negative patients and 223 from 953 HIV positive patients. There were 233 significant faecal isolates, 22 from 115 HIV negative patients and 211 from 531 HIV positive patients. The most common pathogens detected in blood were Streptococcus pneumoniae and Salmonella typhimurium and in faeces Shigella flexneri, S. typhimurium and Cryptosporidium parvum. The agents causing illness in HIV positive patients in Nairobi are similar to those prevalent in the HIV negative community and the investigation of a febrile illness with or without diarrhoea in an HIV positive patient should reflect this.

PIP: Researchers conducted a retrospective analysis of stool specimens from 646 adult patients and of blood cultures from 2738 adult patients to examine the etiology of opportunistic infection in HIV-positive individuals in Nairobi, Kenya, and to compare this etiology with the range of pathogens causing disease in the HIV-negative population. Adults at least 15 years old contributed the stool and blood samples that were received at the Wellcome Trust-Kenya Medical Research Institute during 1988-92. The 415 significant blood culture isolates comprised 192 from 1785 HIV-negative patients and 223 from 953 HIV-positive patients. The most frequently detected pathogens in blood included Streptococcus pneumoniae (58 in HIV-positive cases and 25 in HIV-negative cases) and Salmonella typhimurium (56 in HIV-positive cases; 5 in HIV-negative cases). There were 233 significant stool isolates, 211 from 531 HIV-positive patients and 22 from 115 HIV-negative patients. 20 blood cultures and 21 stool cultures had more than 1 significant pathogen. The most commonly detected organisms in the stools were Shigella flexneri (49 for HIV-positive cases and 9 in HIV-negative cases), S typhimurium (40 in HIV-positive cases and 3 in HIV-negative cases), and Cryptosporidium parvum (45 in HIV-positive cases and 0 in HIV-negative cases). With two exceptions, the spectrum of pathogens associated with infection in HIV-positive patients was the same as that for HIV-negative patients. Physicians should consider this when they investigate and manage febrile illness with or without diarrhea in an HIV-positive patient.

Bacteriuria in a cohort of predominantly HIV-1 seropositive female commercial sex workers in Nairobi, Kenya.

Although significant bacteriuria and urinary tract infection are more common in immunocompetent women than men, studies linking HIV immunosuppression with an increased risk of developing urinary infection have so far only been carried out in men. We therefore examined the relationship between bacteriuria and HIV status and CD4+cell count in a relatively homogeneous cohort of female commercial sex workers (CSW) attending a community clinic in Nairobi. Two hundred and twenty-two women were enrolled, and grouped according to HIV status and CD4 count. Group 1 were HIV seronegative (n = 52); Group 2 were HIV seropositive with CD4 + counts above 500 x 10(6)/l (n = 51); Group 3 were HIV seropositive with CD4 + counts between 201 and 500 x 10(6)/l (n = 67); Group 4 were HIV seropositive with CD4+counts below 200 x 10(6)/l (n = 52). Clinical signs and symptoms were noted and mid-stream specimens of urine obtained for culture and sensitivity. Overall 23% (50/222) had significant bacteriuria. The rates in each group respectively were 25%, 29%, 19% and 23% and there was no significant association between bacteriuria and HIV status; or between bacteriuria and level of immuno-suppression as indicated by CD4 + count. Overall 19% (30/222) of women had symptoms (frequency; dysuria; loin pain; smelly urine) or signs (fever; loin tenderness) compatible with urinary tract infection. However there was no significant association between symptoms or signs of infection and bacteriuria or HIV status. A typical range of pathogens, predominantly Enterobacteriaceae, were isolated and there were high rates of resistance to commonly used antimicrobials as well as 10% resistance to ciprofloxacin. Although high rates of significant bacteriuria can occur in highly sexually-active women, this appears unrelated to HIV infection or the level of HIV-related immunosuppression and is generally asymptomatic or clinically indistinct.

Invasive pneumococcal disease in a cohort of predominantly HIV-1 infected female sex-workers in Nairobi, Kenya.

BACKGROUND: HIV infection is a major risk factor for pneumococcal disease in industrialised countries. Although both are common infections in sub-Saharan Africa, few studies have investigated the importance of this interaction. We have followed up a cohort of female sex-workers in Nairobi and report here on the extent of invasive pneumococcal disease. METHODS: A well-established cohort of low-class female sex-workers, based around a community clinic, was followed up from October, 1989, to September, 1992. 587 participants were HIV positive and 132 remained HIV negative. Set protocols were used to investigate common presentations. Cases were identified clinically and radiographically. Streptococcus pneumoniae and other pathogens were diagnosed by culture. FINDINGS: Seventy-nine episodes of invasive pneumococcal disease were seen in the 587 HIV-positive women compared with one episode in the 132 seronegative women (relative risk 17.8, 95% CI 2.5 to 126.5). In seropositive women the incidence rate was 42.5 per 1000 person-years and the recurrence rate was 264 per 1000 person-years. By serotyping, most recurrent events were re-infection. A wide spectrum of HIV-related pneumococcal disease was seen: only 56% of cases were pneumonia; sinusitis was seen in 30% of cases, and occult bacteraemia, a novel adult presentation, in 11%. Despite forty-two bacteraemic episodes, no deaths were attributable to Strep pneumoniae. At first presentation the mean CD4 cell count was 302/microL(SD 191) and was 171/microL (105) for recurrent episodes. During acute Strep pneumoniae infection the CD4 cell count was reversibly suppressed (mean fall in sixteen episodes, 105/microL [123]). The neutrophil response to acute infection was blunted and was correlated with CD4 count (r=0.50, 95% CI 0.29 to 0.66). Strep pneumoniae caused more disease, at an earlier stage of HIV immunosuppression, than Mycobacterium tuberculosis or non-typhi salmonellae. INTERPRETATION: Our study highlights the importance of the pneumococcus as an early but readily treatable complication of HIV infection in sub-Saharan Africa.

Serotypes and antibiotic susceptibilities of Streptococcus pneumoniae in Nairobi, Kenya.

Two hundred and sixteen clinically significant isolates of Streptococcus pneumoniae from 138 adult patients attending clinics in Nairobi, Kenya over a 2 year period were characterized by antibiotic sensitivity testing and serotyping. Overall antibiotic resistance rates were: penicillin, 25%; tetracycline, 34%; erythromycin, 0%; chloramphenicol, 0.4%. Minimum inhibitory concentrations (MIC's) of penicillin ranged from < 0.008-0.5 microgram/ml. Determination of penicillin resistance (MIC > or = 0.1 microgram/ml) by oxacillin 1 microgram disc diffusion zone diameter < or = 20 mm was 100% sensitive, 92% specific. Relative resistance to oxacillin (MIC range 0.25-1.0 microgram/ml) accounted for penicillin sensitive isolates determined falsely to be penicillin resistant by oxacillin disc testing. Penicillin resistance was more frequent in sputum isolates at 35% than in blood isolates at 18% (P = 0.013). Serotypes 6, 10, 14, 16, 19 and 23 were associated with penicillin resistance. This study provides information of value for planning management strategies for pneumococcal disease from an area where there are few existing data.

Characterization of Streptococcus pneumoniae from human immunodeficiency virus--seropositive patients with acute and recurrent pneumonia.

Thirty-two isolates of clinically significant Streptococcus pneumoniae from 11 human immunodeficiency virus (HIV)-seropositive patients with single or multiple episodes of pneumonia were characterized by antibiotic susceptibility testing, serotyping, ribotyping, and repetitive extragenic palindromic polymerase chain reaction (REP-PCR). The isolates comprised 10 serotypes, 12 ribotyping patterns, and 12 REP-PCR patterns. There was close but not absolute correlation between techniques. By combining these characterization methods, 14 strains were identified. Five strains were found in > 1 patient, suggesting their frequent occurrence in this population. Two isolates of different serotype from 1 patient were highly related by ribotyping and REP-PCR, suggesting possible in vivo serotype change. Acute infection was associated with single strains or coinfection by distinct strains. Recurrent pneumonia was identified as relapse with the same strain or reinfection with new strains. The molecular characterization of pneumonococci from HIV-seropositive persons refines our understanding of pneumonococcal infection in these patients.

Disseminated Mycobacterium avium infection among HIV-infected patients in Kenya.

Previous studies from Africa have been unable to identify disseminated Mycobacterium avium complex (MAC) infection in patients with advanced human immunodeficiency virus (HIV) infection. We performed mycobacterial blood cultures and CD4 counts on 48 symptomatic adults with advanced HIV infection admitted to the hospital in Nairobi, Kenya over 4 weeks in 1992. Fourteen patients had mycobacteremia; these patients had significantly lower CD4 counts than the patients with negative cultures (14/mm3 vs. 85/mm3; p < 0.01). Three patients (6%) were bacteremic with M. avium (mean CD4 count, 10/mm3) and 11 (23%) were bacteremic with Mycobacterium tuberculosis complex (MTB) (mean CD4 count, 15/mm3). Thus, M. avium bacteremia was detected significantly less frequently in the study population than MTB bacteremia (p = 0.04). The minimum rate for HIV-associated disseminated M. avium infection in patients admitted to the hospital in Nairobi was estimated to be approximately 1%. Patients with mycobacteremia died or were discharged home sick before the diagnosis was made. Disseminated M. avium does occur in adults with advanced HIV infection in sub-Saharan Africa, but is less common than disseminated MTB.

Antimicrobial susceptibility and presence of extrachromosomal deoxyribonucleic acid in Salmonella and Shigella isolates from patients with AIDS.

The development of multi-drug resistance by enteric bacteria is an increasing problem in the developing countries. There is need to monitor antimicrobial susceptibility of these organisms in order to ensure appropriate treatment and control of infections. Antimicrobial susceptibility patterns, plasmid DNA content and restriction enzyme digests of plasmid deoxyribonucleic acid (DNA) were used to study 175 Salmonella and Shigella species isolated from predominantly HIV-seropositive adult patients in Nairobi, Kenya. All the isolates were sensitive to ciprofloxacin. A significantly higher proportion of Shigella species were resistant to chloramphenicol, cotrimoxazole, streptomycin and tetracycline compared to Salmonella species (p-value < 0.001). Multi-resistant Salmonella typhimurium isolates had 60, 40 and 5 MDa plasmids, the 5 MDa plasmid was absent in gentamicin sensitive isolates. In addition to 2-10 MDa range of plasmids, multi-resistant Shigella species had a heavy 100-105 MDa plasmid. Restriction enzyme digests were similar for the 60 and 40 MDa plasmid DNA bands from Salmonella typhimurium isolates but did not show any consistency among Shigella spp. Plasmid-encoded multi-drug resistance plays a major role in the spread of resistance among enteric bacteria. It is vital to use drugs rationally in order to control the emergence and spread of multi-drug resistance.

Infection and morbidity in patients with tuberculosis in Nairobi, Kenya.

OBJECTIVE: To examine the role of acute infection as a cause of morbidity in patients with tuberculosis. DESIGN: Cross-sectional documentation of predefined acute morbid events. SETTING: Infectious Diseases Hospital, Nairobi, Kenya. PATIENTS: Adults (> or = 15 years), inpatients and outpatients with a diagnosis of tuberculosis presenting with one or more of a series of clinical features. A new event was defined as one occurring at least 1 week after the initial event. INTERVENTIONS: Patients' treatment was modified depending on the results of laboratory investigations. MAIN OUTCOME MEASURES: There were 642 events from 398 patients, 235 HIV-positive patients had 438 events and 163 HIV-negative patients had 204 events (P < 0.0001). Forty-two out of the 235 (18%) HIV-positive patients were bacteraemic compared with nine out of the 163 (6%) HIV-negative patients (P = 0.0003). The most common isolates from blood were Salmonella typhimurium and Streptococcus pneumoniae. RESULTS: Faecal specimens were obtained more commonly from HIV-positive patients (P < 0.001), and often contained bacterial pathogens. CONCLUSIONS: Many of the causes of morbidity in patients with tuberculosis and HIV are not due to tuberculosis or antituberculous therapy, and will not be identified without microbiological investigation.

PIP: Tuberculosis (TB) is a common complication of HIV in Africa. A 1988-89 study further confirmed that considerable morbidity and mortality from acute bacterial infection occurred in HIV patients. It has also been found that anti-TB therapy seems to be as effective in HIV-positive as in HIV-negative TB patients. This paper reports on the level and nature of infectious morbidity suffered by HIV-positive patients receiving treatment for TB. The assessment is based upon a sample of inpatients and outpatients at the Infectious Diseases Hospital in Nairobi. Patients were aged 15 years and older, with a TB diagnosis presenting with 1 or more of a series of clinical features. 642 morbid events were seen in 398 patients: 235 HIV-positive patients had 438 event and 163 HIV-negative patients had 204 events. 18% of the HIV-positive patients versus 6% of the HIV-negative patients were bacteremic. Salmonella typhimurium and Streptococcus pneumoniae were most commonly isolated from sera, while fecal specimens were obtained more commonly from HIV-positive patients and often contained bacterial pathogens. The authors conclude that many causes of morbidity in patients with TB and HIV are not due to TB or anti-TB therapy and will not be identified without microbiological investigation. These results suggest that even with effective anti-TB chemotherapy HIV-positive patients will remain or become unwell.