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.

Antibodies to opacity proteins (Opa) correlate with a reduced risk of gonococcal salpingitis.

Acute salpingitis complicating cervical gonococcal infection is a significant cause of infertility. Relatively little data are available concerning the pathophysiologic mechanisms of this disease. A cohort of 243 prostitutes residing in Nairobi were followed between March 1985 and April 1988. Gonococcal cultures were performed at each visit, and acute salpingitis was diagnosed clinically. Serum at enrollment was tested by immunoblot for antibody to gonococcal outer membrane proteins. 8.6% (146/1689) of gonococcal infections were complicated by salpingitis. Increased risk of salpingitis was associated with younger age, shorter duration of prostitution, HIV infection, number of gonococcal infections, and episodes of nongonococcal salpingitis. Rmp antibody increased the risk of salpingitis. Antibody to Opa decreased the risk of salpingitis. By logistic regression analysis, antibody to Opa was independently associated with decreased risk of gonococcal salpingitis (adjusted odds ratio [OR], 0.35; 95% confidence interval [95%CI], 0.17-0.76); HIV infection (adjusted OR, 3.5; 95% CI, 0.96-12.8) and episodes of nongonococcal salpingitis (adjusted OR, 3.4; 95% CI, 1.8-6.4) were independently associated with an increased risk of salpingitis. Antibody to Opa appears to protect against ascending gonococcal infection, perhaps by interfering with Opa mediated adherence and endocytosis. The demonstration of natural immunity that protects against upper genital tract infection in women suggests that a vaccine to prevent gonococcal salpingitis is possible.

Antibody to Rmp (outer membrane protein 3) increases susceptibility to gonococcal infection.

The severe adverse effects of gonococcal infection on human fertility suggests that Neisseria gonorrhoeae would exert powerful selection for the development of a protective immune response in humans. N. gonorrhoeae is an obligate human pathogen and must persist in humans to survive. Since it is an ecologically successful organism, it must have evolved strategies to evade any human immune response it elicits. In a longitudinal study among 243 women working as prostitutes and experiencing frequent gonococcal infection, younger women, women with HIV infection, and women with antibody to the gonococcal outer membrane protein 3 (Rmp) were at increased risk of infection (adjusted odds ratio 3.4, CI95% 1.1-10.4, P < 0.05). Rmp is highly conserved in N. gonorrhoeae and the blocking of mucosal defences may be one of its functions. As similar proteins occur in many gram negative mucosal pathogens, the enhancing effect of such proteins may be a general strategy whereby bacteria evade human immune responses.

PIP: Between March 1985 and July 1986 researchers enrolled 243 female prostitutes in Pumwani community of Nairobi, Kenya, in a longitudinal study to examine the relationship between the antibody to the gonococcal outer membrane protein 3 (Rmp Ab) and gonococcal mucosal infection. Few women used condoms. 69% were HIV-1 seropositive. Just 9.5% (23) of the women had not had any gonococcal infections, despite probable exposure to them, indicating the possibility of some acquired protective immunity to Neisseria gonorrhoea. 90.5% had had at least 1 gonococcal infection. Women with Rmp Ab faced a greater risk of gonococcal infection than those who were Rmp Ab negative (OR = 3.4;l p .05), denoting that Rmp Ab increases susceptibility to gonococcal mucosal infections. Women older than 29 years were at lower risk of gonococcal infection than those younger than 29 years (odds ratio [OR] = 0.3; p .03). Women who used oral contraceptives (OCs) were also likely to be infected with N. gonorrhoea (OR = 3; p = .062). Further, 31% of OC users had cervical ectopy compared to just 14% of nonusers (OR = 2.8; p .005), suggesting that the effect of OCs on the cervix make it more susceptible to gonococcal infection. Rmp Ab also exists in many other gram-negative mucosal pathogens, often playing the same role as it does in N. gonorrhoea infection. Thus, Rmp Ab may be a common scheme bacteria used to elude human immune responses. These findings provide more understanding as to why N. gonorrhoea is an ecologically successful human pathogen.

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.

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.

HIV infection among lower socioeconomic strata prostitutes in Nairobi.

A cohort of 418 lower socioeconomic strata prostitutes were enrolled in a study of the epidemiology of sexually transmitted diseases (STDs) between January and April 1985. Sixty-two per cent of the women were seropositive for HIV infection at enrollment. Significant associations were found between HIV seropositivity and Tanzanian origin (OR = 2.12, CI 95% = 1.18-3.81, P less than 0.03), younger age, a shorter duration of prostitution, reduced fecundity, use of oral contraceptives (OR = 1.8, CI 95% = 1.1-2.9, P less than 0.05) and genital ulcer disease (OR = 3.32, P less than 0.00001). No associations were noted with other STD. Stepwise logistic regression analysis confirmed independent associations between HIV infection and Tanzanian origin (OR = 2.27, CI 95% = 1.25-4.14, P less than 0.007), reduced fecundity (OR = 0.83, CI 95% = 0.74-0.94, P less than 0.003), oral contraceptive use (OR = 2.02, CI 95% = 1.22-3.35, P less than 0.006) and duration of prostitution (OR = 0.39, CI 95% = 0.23-0.65, P less than 0.004). Oral contraceptives may increase susceptibility to HIV or may be a marker for other factors which increase risk of acquisition. Further studies are necessary to confirm this association.

Effect of piped water supply on human water contact patterns in a Schistosoma haematobium-endemic area in Coast Province, Kenya.

The effect of a piped water supply on human water contact in a Schistosoma haematobium-endemic area in Coast Province, Kenya was studied. After the construction of five community standpipes and one shower unit, there was a 35.1% reduction in the number of people observed using river water, a 44.1% reduction in the frequency of contact with river water, and a 25.4% reduction in the amount of contact. The frequency of river water contact per person also decreased significantly, but the amount of contact per person did not decrease. The total frequency of contact decreased significantly except for washing clothes by the river, washing utensils, and fishing. The frequency per person did not change for most of the activities and significantly increased for washing clothes. The frequency of river water contact in households with high piped water consumption showed a significant decrease compared with those with low piped water consumption. The volume of consumption of piped water was inversely proportional to the distance from the home to the community standpipe. These results indicate that in the study area, the effect of a piped water supply on river water contact behavior was heterologous while the total river water contact decreased significantly, and that the piped water had a beneficial effect on some villagers but very little effect on others.

Transmission of epidemic Vibrio cholerae O1 in rural western Kenya associated with drinking water from Lake Victoria: an environmental reservoir for cholera?

Sub-Saharan Africa has the highest reported cholera incidence and mortality rates in the world. In 1997, a cholera epidemic occurred in western Kenya. Between June 1997 and March 1998, 14,275 cholera admissions to hospitals in Nyanza Province in western Kenya were reported. There were 547 deaths (case fatality rate = 4%). Of 31 Vibrio cholerae O1 isolates tested, all but one were sensitive to tetracycline. We performed a case-control study among 61 cholera patients and age-, sex-, and clinic-matched controls. Multivariate analysis showed that risk factors for cholera were drinking water from Lake Victoria or from a stream, sharing food with a person with watery diarrhea, and attending funeral feasts. Compared with other diarrheal pathogens, cholera was more common among persons living in a village bordering Lake Victoria. Cholera has become an important public health concern in western Kenya, and may become an endemic pathogen in the region.

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.

Toxoplasma antibodies in HIV-positive patients from Nairobi.

Sera from 94 patients infected with human immunodeficiency virus (HIV) 1, together with 86 controls, attending the Kenyatta National Hospital, Nairobi were examined for antibodies to Toxoplasma gondii using enzyme immunoassay and latex and dye tests. 54% had Toxoplasma-specific immunoglobulin G (IgG) by dye test. 22% of the HIV-positive group had IgG levels in excess of 180 units/ml (approximating to a dye test titre of 1:1300) compared to 1% of the HIV-negative group. There was no correlation between high levels of IgG and clinical stage of HIV disease or features indicative of active toxoplasmosis. It is proposed that the elevated serum IgG is a reflection of early Toxoplasma reactivation, not necessarily associated with disease.

PIP: Health workers took blood samples from 94 HIV positive patients (cases) and 86 HIV negative patients (controls) at the Kenyatta National Hospital in Nairobi, Kenya. Researchers compared the serological results of both groups to determine if any serological evidence of reactivation of latent infection existed and, if so, whether this reactivation could be related to acute toxoplasmosis. Laboratory personnel tested all serum with EIA and latex agglutination and dye tests to determine the presence of anti-Toxoplasma antibodies (Toxoplasma IgG). Both the EIA and latex test were more sensitive and specific in detecting Toxoplasma IgG than the dye test. The dye test revealed 54% of all patients had Toxoplasma IgG. Further 22% of the cases had IgG levels 180 units/ml whereas only 1% of controls had these levels. None of the patients exhibited any signs or symptoms of toxoplasmic encephalitis. Further no correlation between high Toxoplasma IgG titers and signs of central nervous system dysfunction or confusion occurred. Even though 35% of cases had considerable lymphadenopathy, it was not associated with Toxoplasma IgG levels. Moreover Toxoplasma IgG levels were not related to AIDS or death. The researchers concluded that high serum IgG levels were indicative of early Toxoplasma reactivation and necessarily associated with disease.

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.

Haematological and biochemical changes in cattle poisoned by Gnidia latifolia syn. Lasiosiphon latifolius (Thymelaeaceae).

Haematological and serum biochemical examinations were carried out on 12 high grade bull calves fed Gnidia latifolia (Meisn). This resulted in lymphocytopaenia, increased blood urea nitrogen and lactate dehydrogenase. There were no changes in the red blood cell counts, neutrophil counts, aspartate amino transferase, creatine phosphokinase and alkaline phosphatase. There was also no change in serum protein concentration. Post-mortem changes in the acutely intoxicated calves included petechial haemorrhages of the epicardium and submucosa of the rumen, abomasum and the intestines. The chronic cases showed a generalized emaciation with gelatinous atrophy of the body fat and accumulation of excess fluid in the body cavities. The lymph nodes and spleen showed lymphocytic degeneration with cellular depletion in the follicles. There were extensive liver fibroses in the chronic cases.

Chronic diarrhoea among HIV-infected adult patients in Nairobi, Kenya.

OBJECTIVES: Chronic diarrhoea and wasting are well recognized features of AIDS in Africa. However, because of resource constraints few comprehensive aetiological studies have been conducted in sub-Saharan Africa which have included a broad range of microbiological investigations. We undertook a prospective cross-sectional study of adult patients admitted to a government hospital in Nairobi, Kenya, to determine possible bacterial, mycobacterial, parasitic and viral causes of diarrhoea; to consider which may be treatable; and to relate microbiological findings to clinical outcome. METHODS: Stool specimens from 75 consecutive HIV-seropositive patients with chronic diarrhoea admitted to a Nairobi hospital were subjected to microbiological investigation and results were compared with clinical findings and outcome. Stool samples were cultured for bacteria and mycobacteria and underwent light and electron microscopy; lawns of Escherichia coli were probed for pathogenic types and aliquots were tested for the presence of Clostridium difficile cytotoxin. Blood cultures for mycobacteria and other bacterial pathogens were performed as clinically indicated. RESULTS: Thirty-nine (52%) patients yielded putative pathogens, the most common being Cryptosporidium sp. (17%), Salmonella typhimurium (13%), and Mycobacterium tuberculosis (13%). Of 41 patients investigated for pathogenic Escherichia coli, enteroaggregative E. coli and diffusely adherent E. coli were each found in four patients. Thirty-one (41%) patients died. Detection of cryptosporidium cysts was the single most significant predictor of death (X2 = 5.2, P<0.05). Many patients did not improve (21; 28%) or self-discharged whilst still sick (5; 7%) but five (7%) were diagnosed ante mortem with tuberculosis and treated and a further 13 (17%) showed improvement by time of discharge. CONCLUSIONS: HIV-infected patients with chronic diarrhoea in Nairobi have a poor outcome overall, and even with extensive investigation a putative pathogen was identified in only just over half the patients. The most important step is to exclude tuberculosis; and the most useful investigation appears to be Ziehl-Neelsen staining. Other potentially treatable gram-negative bacterial pathogens, S. typhimurium, Shigella sp. and adherent E. coli were, however, common but require culture facilities which are not widely accessible for definitive identification. Further studies focussing on simple ways to identify sub-groups of patients with treatable infections are warranted.

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.

Use of malaria prevention measures by North American and European travelers to East Africa.

BACKGROUND: The use of preventive measures, including effective chemoprophylaxis, is essential for protection against malaria among travelers. However, data have shown that travelers and medical advisors are confused by the lack of uniform recommendations and numerous prophylactic regimens of varying effectiveness that are used. METHODS: To assess the use and type of preventive measures against malaria, we conducted a cross-sectional study in 1997 among travelers departing from the Nairobi and Mombasa airports in Kenya with European destinations. RESULTS: Seventy-five percent of the travelers studied were residents of Europe and 25% were residents of North America; all stayed less than 1 year, and visited malarious areas. Most travelers, 97.1%, were aware of the risk and 91.3% sought pretravel medical advice. Although 95.4% used chemoprophylaxis and/or antimosquito measures, only 61.7% used both regular chemoprophylaxis and two or more antimosquito measures. Compliance with chemoprophylaxis was lowest amongst those who used a drug with a daily, as opposed to, a weekly dosing schedule, stayed more than 1 month, attributed an adverse health event to the chemoprophylaxis, and were less than 40 years of age. Among US travelers, 94.6% of those taking chemoprophylaxis were taking an effective regimen, that is, mefloquine or doxycycline. Only 1.9% used a suboptimal drug regimen, such as chloroquine/proguanil. Among European travelers, 69% used mefloquine or doxycycline, and 25% used chloroquine/proguanil. Notably, 45.3% of travelers from the UK used chloroquine/proguanil. Adverse events were noted by 19.7% of mefloquine users and 16.4% of travelers taking chloroquine/proguanil. Neuropsychologic adverse events were reported by 7.8% of users of mefloquine and 1.9% of those taking chloroquine/proguanil. The adverse events, however, had a lesser impact on compliance than frequent dosing schedule. CONCLUSIONS: Health information should be targeted to travelers who are likely to use suboptimal chemoprophylaxis or may be noncompliant with prophylaxis. Uniform recommendations for effective chemoprophylaxis with simple dosing schedules are necessary to reduce rates of malaria among travelers to Africa.

Specific and shared antigenic components of Taenia saginata oncospheres.

Taenia saginata oncosphere components were analysed by double diffusion. Antigenic components in saline or detergent (Triton x-100) extracts of T saginata oncospheres were identified using a rabbit polyclonal serum directed against the oncosphere and compared with extracts prepared from the metacestodes and proglottids of T saginata and six other helminths commonly found in cattle. There were seven antigenic components found in the saline extract of the oncospheres, of which six were shared with the metacestodes and proglottids. None of these components was consistently different from those of the other six helminths. However, one of the four components in the detergent extract of the oncospheres was present in neither of the extracts of other stages of T saginata nor in extracts of other helminths. This may be of diagnostic significance.

Cholera: its story in Africa with special reference to Kenya and other east African countries.

Cholera is an acute often fatal infection whose aetiology, epidemiology, clinical presentation, management, prevention and control are well understood. However, the disease has recently re-emerged as a serious microbial threat due to environmental pressures, increased international travel, population migrations and the emergence of new strains of "old" pathogens. This paper emphasizes, the significance of putting into place quick surveillance methods backed by laboratory services and the importance of creating a rapid response capacity and mechanics to outbreaks.

The fimbriae-like structures on V. cholerae isolated in Kenya.

For Vibrio cholerae 01 to overcome the normal intestinal clearing mechanisms and facilitate colonization in the host gut, fine filamentous structures covering the surface of all the cell must exist. These fimbriae-like structures were investigated in this study. Selection of the K23 V. cholerae 01 biotype el-tor isolated in Kisumu, Kenya, was based on its proteinase activity and ability to agglutinate 0.2M ammonium sulphate. This strain was cultured in modified tryptone broth pH 8.4, at 37 degrees C overnight. Electron microscopy of the strain revealed the presence of fimbriae-like structures which varied in number. Some cells showed more than 200, whereas in other cells only several filamentous structures were detected. It is suggested that these structures could be a possible candidate for a cholera vaccine.

Enterotoxigenic Escherichia coli infection in childhood diarrhoea in Mombasa, Kenya.

PIP: This study was carried out at the Coast General Hospital in Mombasa, Kenya, during the dry month of March, 1984. Stool specimens were collected from 81 infants and children aged 0-36 months and with diarrhea of less than 7 days' duration. 35 age-matched children, who visited the hospitals with complaints other than gastrointestinal, served as controls. None of the children had received previous antibiotic therapy. Stools were checked for enterotoxigenic Escherichia coli (ETEC). E. coli isolates were assayed for labile toxin (LT) and stable toxin (ST) production by the Biken test and the suckling mouse assay, respectively. 19 ETEC were isolated from children with diarrhea, constituting an isolation rate of 23.5%. No ETEC were isolated from the controls. ST producers predominated (94.7%). Results indicate that the rates of ETEC isolation increase with age. In the majority of cases (16/19) ETEC caused diarrhea which was watery, with the number of motions ranging from 3 to 10 times. Fever was present in 9 patients. Mucus and blood were observed in very few cases. Vomiting was frequent (10/19) but abdominal pain was less common (5/10).^ieng

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.

PIP: A retrospective review of medical records of 6514 Mycobacterium tuberculosis isolates of newly diagnosed patients at the Respiratory Diseases Research Unit of the Kenya Medical Research Institute between 1981 and 1990 aimed to determine the initial drug-resistance pattern for isoniazid, streptomycin, and rifampicin. Overall resistance increased from 8.9 to 14.4% (p 0.001). The increase in the resistance trend to isoniazid and to streptomycin were statistically significant (6.8-10.2; p 0.05 and 0.8-1.8; p = 0.03, respectively) as well as the trend among isolates resistant to both isoniazid and streptomycin (1.2.4; p = 0.03). The trend was more pronounced during 1987-1990 than during 1981-1986. There was no trend in the resistance to rifampicin alone (0.1-0.3%). Just 4 isolates were resistant to both isoniazid and rifampicin. Only 1 was resistant to both streptomycin and rifampicin. None were resistant to all 3 antibiotics. These first-line drugs are used widely in Kenya. These rates of initial resistance to the drugs are lower than those in other developing countries. The lower resistance rate is unlikely to continue, however, due to higher prevalence of HIV infection and the associated increase in tuberculosis incidence. These findings provide researchers a baseline with which to study M. tuberculosis drug resistance and other risk factors as drug resistance increases in Kenya.