Persistent inequalities in 90-day colon cancer mortality: an English cohort study.

BACKGROUND: Variation in colon cancer mortality occurring shortly after diagnosis is widely reported between socio-economic status (SES) groups: we investigated the role of different prognostic factors in explaining variation in 90-day mortality. METHODS: National cancer registry data were linked with national clinical audit data and Hospital Episode Statistics records for 69 769 adults diagnosed with colon cancer in England between January 2010 and March 2013. By gender, logistic regression was used to estimate the effects of SES, age and stage at diagnosis, comorbidity and surgical treatment on probability of death within 90 days from diagnosis. Multiple imputations accounted for missing stage. We predicted conditional probabilities by prognostic factor patterns and estimated the effect of SES (deprivation) from the difference between deprivation-specific average predicted probabilities. RESULTS: Ninety-day probability of death rose with increasing deprivation, even after accounting for the main prognostic factors. When setting the deprivation level to the least deprived group for all patients and keeping all other prognostic factors as observed, the differences between deprivation-specific averaged predicted probabilities of death were greatly reduced but persisted. Additional analysis suggested stage and treatment as potential contributors towards some of these inequalities. CONCLUSIONS: Further examination of delayed diagnosis, access to treatment and post-operative care by deprivation group may provide additional insights into understanding deprivation disparities in mortality.

Resistance to antibiotics in urinopathogenic bacteria isolated in patients attending Kenyatta University Health Clinic, Nairobi.

OBJECTIVE: To determine the aetiological bacterial agents of urinary tract infections, within communities in Kenyatta University, and current resistance levels to commonly available therapeutic agents. DESIGN: Cross-sectional survey research design. SETTING: Kenyatta University Health Services Clinic, Nairobi. SUBJECTS: Outpatients with symptoms of urinary tract infection within the six months study duration were observed. RESULTS: Females were particularly prone to have confirmed cases of UTI. Escherichia coli were the principle aetiological agent accounting for 61.7% of the isolates. Other bacterial agents were Enterobacter agglomerans (18.7%), Citrobacter diversus (4%), Klebsiella pneumoniae (3.3%), Proteus spp. (2.1%), Pseudomonas spp. (0.1%), Staphylococcus saprophyticus (9.3%), and Streptococcus feacalis (0.7%). Over 60% of the Gram negative bacterial isolates were resistant to cotrimoxazole and ampicillin, 39% resistant to augmentin and 25% were resistant to nalidixic acid. The ceftazidime was the most efficacious antimicrobial with an Escherichia coli resistance level of 2.2% (P=0.05). Resistance to nitrofuraintoin, gentamicin, cefuroxime, norfloxacin and ciprofloxacin was demonstrated in less than 15% of the bacterial isolates. CONCLUSION: The cephalosporins, fluoroquinolones, nitrofurantoin and gentamicin have good efficacy against the uropathogenic bacteria and may be good therapeutic choices when culture results are unavailable. High resistance levels exist against cotrimoxazole, ampicillin, augmentin, and nalidixic acid. These later antibiotics should therefore be used against the uropathogenic bacteria with caution.

Prevalence of cytomegalovirus antibodies in blood donors at the National Blood Transfusion Centre, Nairobi.

BACKGROUND: Cytomegalovirus (CMV) infection in susceptible patients is associated with serious morbidity and a high mortality. Transmission of cytomegalovirus infection through blood transfusion is markedly reduced by transfusion of CMV seronegative blood products, or by transfusion of leucodepleted blood products. OBJECTIVE: To determine the prevalence CMV IgG and IgM antibodies among blood donors at the National Blood Transfusion Services (NBTS), Nairobi. DESIGN: Cross-sectional descriptive study. SETTING: Four hundred participants were recruited from blood donors at the NBTS and testing was done at the Kenyatta National Hospital (KNH) immunology laboratories and the NBTC. MAIN OUTCOME MEASURES: Social demographic data and the CMV serologic status for the participants was determined and documented as being positive or negative for immunoglobulin G (IgG) and immunoglobulin M (IgM). The age, gender, marital status, education level and geographical area of residence of the participants were documented. Corresponding results of HIV, hepatitis B antigen, hepatitis C antibody from the patients were obtained from the NBTS. RESULTS: Majority of the blood donors recruited were male at 57.9%. Most blood donors were aged 16-20 years (42.5%) and only 17.2% were above 30 years of age. Unmarried blood donors, those with secondary school education and an income between Kshs 5000 (US $67) and KShs 50,000 (US$ 667) monthly were the majority at 78.5%, 54.8% and 66.1% respectively. Sexually active blood donors constituted 60.5% of the donors recruited. Positivity for transfusion transmissible infections (TTI) tested was 1.3%, 0.3%, 2.3% and 1.0% for human immunodeficiency virus (HIV), syphilis, hepatitis B and hepatitis C respectively. Anti- CMV IgG and IgM positivity was 97.0%, (95% CI 96.45-97.53%), and 3.6% (95% CI 1.7-5.2%), respectively. There was no statistical difference between different ages, marital status, salary, individual's sexuality in the prevalence of CMV antibodies. However females had a higher prevalence of CMV antibodies. CONCLUSION: There is a very high prevalence of cytomegalovirus antibodies among blood donors at the NBTS, with virtually all blood donors having been exposed to the virus. Since the CMV remains latent within leucocytes after infection inspite of the prescence of antibodies in seropositive individuals, leucoreduction of blood products is recommended before transfusion to seronegative susceptible patients. In Kenya, susceptible groups of patients include very low birthweight babies, patients with acquired immune deficiency syndrome (AIDS) due to human immunodeficiency virus infections (HIV) patients, patients on myelosuppressive cancer therapy and recipients of kidney transplants. Further studies are recomended to determine the prevalence of CMV antibodies in these patients in order to establish the magnitude of the demand for CMV safe blood.

Subclinical nephrotoxicity associated with occupational silica exposure among male Kenyan industrial workers.

OBJECTIVE: To determine early signs of renal injury due to occupational silica exposure. DESIGN: Cross-sectional analytical research. SETTINGS: Kenyatta National Hospital for the referent population and Clayworks ceramics, bricks and tiles factory for the assessment of occupational silica exposure. SUBJECTS: Thirty three non-smoking silica-exposed male industrial workers and 38 non-smoking male referents participated in this study. RESULTS: Silica-exposed males excreted significantly increased levels of U.TP, U.Malb, U.ALP, U.y-GT and U.LDH compared to referent males. Among the silica-exposed males, U.Si negatively correlated significantly with age, U.TP correlated significantly to each of U.ALP and U.LDH. However, no correlation was observed between work duration and U.Si. CONCLUSION: The present study shows that there is associated glomerular and proximal tubular damage among silica exposed workers which is not duration related and is seemingly subclinical and nonprogressive and urinary silica levels appears to be similar in all groups and are not affected by exposure and work duration: the reason for which is unclear.

The in vitro anti-plasmodial and in vivo anti-malarial efficacy of combinations of some medicinal plants used traditionally for treatment of malaria by the Meru community in Kenya.

The use of herbal drugs as combinations has existed for centuries in several cultural systems. However, the safety and efficacy of such combinations have not been validated. In this study, the toxicity, anti-plasmodial and antimalarial efficacy of several herbal drug combinations were investigated. Lannea schweinfurthii, Turraea robusta and Sclerocarya birrea, used by traditional health practitioners in Meru community, were tested for in vitro anti-plasmodial and in vivo anti-malarial activity singly against Plasmodium falciparum and Plasmodium berghei, respectively. Methanolic extract of Turraea robusta was the most active against Plasmodium falciparum D6 strain. Aqueous extracts of Lannea schweinfurthii had the highest anti-plamodial activity followed by Turraea robusta and Sclerocarya birrea. D6 was more sensitive to the plant extracts than W2 strain. Lannea schweinfurthii extracts had the highest anti-malarial activity in mice followed by Turraea robusta and Sclerocarya birrea with the methanol extracts being more active than aqueous ones. Combinations of aqueous extracts of the three plants and two others (Boscia salicifolia and Rhus natalensis) previously shown to exhibit anti-plasmodial and anti-malarial activity singly were tested in mice. Marked synergy and additive interactions were observed when combinations of the drugs were assayed in vitro. Different combinations of Turraea robusta and Lannea schweinfurthii exhibited good in vitro synergistic interactions. Combinations of Boscia salicifolia and Sclerocarya birrea; Rhus natalensis and Turraea robusta; Rhus natalensis and Boscia salicifolia; Turraea robusta and Sclerocarya birrea; and Lannea schweinfurthii and Boscia salicifolia exhibited high malaria parasite suppression (chemo-suppression >90%) in vivo when tested in mice. The findings are a preliminary demonstration of the usefulness of combining several plants in herbal drugs, as a normal practice of traditional health practitioners.

Microbiological quality and safety of Rastrineobola argentea retailed in Kisumu town markets, Kenya.

OBJECTIVE: To investigate faecal contamination and safety of Rastrineobola argentea sold in retail markets in Kisumu town. DESIGN: This was a repeated cross sectional study and based on random sampling. SETTING: Kisumu city, targeting six markets; Oile, Jubilee, Kibuye, Kondele, Nyalenda and Manyatta. RESULTS: A total of 60 fish samples were analysed. All the fish were found to be contaminated with E. coli, and in addition 6.67% of the fish products tested positive for Salmonella. Shigella was absent in all samples analysed. 26.53% of E. coli isolates tested were resistant to two or more antimicrobial agents tested, with the highest level of resistance detected against cotrimoxazole at 38.76%. The E. coli multiple antibiotic resistance (MAR) index was 0.084 indicating that the contamination was not originating from a high-risk source. A plasmid of approximately 5.6 kb was commonly isolated from E. coli isolates that showed resistance to ampicillin. Plasmids isolated were not transferable by conjugation. CONCLUSION: The presence of Salmonella spp and occurrence of MDR E. coli were identified as some of the possible health risks that may be associated with R. argentea displayed for sale in Kisumu city markets. This possess a real health risk through consumption or directly through contact with the fish products.

Environmental and occupational exposure to lead.

OBJECTIVE: To determine the status of environmental and occupational lead exposure in selected areas in Nairobi, Kenya. DESIGN: Cross sectional study. SETTING: Kariobangi North, Babadogo, Waithaka and Pumwani for assessment of environmental exposure to lead (Pb) and Ziwani Jua Kali works for assessment of occupational lead exposure. Olkalou in Nyandarua District was the covariate study area. SUBJECTS: Three hundred and eight children and adults participated. RESULTS: Blood lead levels (BLLs) obtained for the entire sample (n = 308) ranged from 0.4 to 65 microg/dl of blood. One hundred and sixty nine (55%) of the total sample had levels equal to or below 4.9 microg/dl, while 62 (20%) of the sample had levels ranging from 5.0 to 9.9 microg/dl. Blood lead levels above 10 microg/dl were recorded in 77 (25%) of the total sample. Within Nairobi, 32 (15.3%) of the study subjects in areas meant for assessment of environmental lead exposure had levels above the WHO/CDC action levels of 10 microg/dl of blood. The mean BLL for the occupationally exposed (Ziwani Jua kali) was 22.6 +/- 13.4 microg/dl. Among the workers, 89% had BLLs above 10 microg/dl. In general, 15% of the entire sample (for both environmental and occupational groups) in Nairobi had BLLs above 15 microg/dl. The covariate group at Olkalou had a mean BLL of 1.3 +/- 0.9 microg/dl. CONCLUSION: The prevalence of environmental lead exposure to the general public is high in Nairobi compared to Olkalou where non exposure was reported. Occupational lead exposure has been identified to be at alarming levels and urgent intervention measures are recommended.

Type 2 diabetes mellitus: clinical and aetiologic types, therapy and quality of glycaemic control of ambulatory patients.

BACKGROUND: Type 2 diabetes is a heterogeneous disease with multiple causes revolving around beta cell dysfunction, insulin resistance and enhanced hepatic glucose output. Clinical judgement based on obesity status, age of onset and the clinical perception of residual beta cell insulin secretory function (hence insulin-requiring or not), has been used to determine therapeutic choices for each patient. Further laboratory testing of the clinically defined type 2 diabetes unmasks the various aetiologic types within the single clinical group. OBJECTIVE: To determine the aetiological types of the clinically defined type 2 diabetic patients, their chosen therapies at recruitment and the quality of glycaemic control achieved. DESIGN: Descriptive cross-sectional study. SETTING: Diabetes out-patient clinic of Kenyatta National Hospital, Nairobi, Kenya. RESULTS: A total of 124 patients with clinical type 2 diabetes were included, 49.2% were males. The mean duration of diabetes in males was 26.09 (20.95) months and that of females was 28.68 (20.54) months. The aetiological grouping revealed the following proportions: Type 1A-3.2%, Type 1B-12.1%, LADA-5.7%, and "true" type 2 diabetes 79.0%. All the patients with Type 1A were apparently, and rightly so, on "insulin-only" treatment even though they did not achieve optimal glycaemic control with HbA1c % = 9.06. However the study patients who were type 1B and LADA were distributed all over the treatment groups where most of them did not achieve optimal glycaemic control, range of HbA1c of 8.46 -10.6%. The patients with "true" type 2 were also distributed all over the treatment groups where only subjects on 'diet only' treatment had good HbA1c of 6.72% but those in other treatment groups did not achieve optimal glycaemic control of HbA1c, 8.07 - 9.32%. CONCLUSION: Type 2 diabetes is a heterogeneous disease where clinical judgement alone does not adequately tell the various aetiological types apart without additional laboratory testing of C-peptide levels and GAD antibody status. This may partly explain the inappropriate treatment choices for the various aetiological types with consequent sub-optimal glycaemic control of those patients.

CD8(+) lymphocytes respond to different HIV epitopes in seronegative and infected subjects.

HIV-1-specific cytotoxic T-lymphocyte (CTL) responses have been detected at a low frequency in many HIV-1-exposed, persistently seronegative (HEPS) subjects. However, it is unclear how CTLs could protect against HIV acquisition in HEPS subjects, when high levels of circulating CTL fail to prevent disease progression in most seropositive subjects. To address this issue we studied CD8(+) lymphocyte responses to a panel of HIV-1 CTL epitopes in 91 HEPS and 87 HIV-1-infected Nairobi sex workers. HIV-specific responses in seropositive women focused strongly on epitopes rarely or never recognized in HEPS subjects, who targeted epitopes that were subdominant or unrecognized in infected women. These differences in epitope specificity were restricted by only those HLA class I alleles that are associated with a reduced risk of HIV-1 infection in this cohort. Late seroconversion in HEPS donors was associated with a switch in epitope specificity and/or immunodominance to those epitopes preferentially recognized by HIV-1-infected women. The likelihood of detecting HIV-1-specific responses in HEPS women increased with the duration of viral exposure, suggesting that HIV-1-specific CD8(+) responses are acquired over time. The association between differential recognition of distinct CTL epitopes and protection from HIV-1 infection may have significant implications for vaccine design.

Late seroconversion in HIV-resistant Nairobi prostitutes despite pre-existing HIV-specific CD8+ responses.

Resistance to HIV infection in a small group of Kenyan sex workers is associated with CD8+-lymphocyte responses to HIV cytotoxic T-lymphocyte (CTL) epitopes. Eleven prostitutes meeting criteria for HIV resistance seroconverted between 1996 and 1999. The occurrence and specificity of preexisting HIV-1 epitope-specific responses were examined using the IFN-gamma enzyme-linked immunospot assay, and any epitopes recognized were cloned and sequenced from the infecting viral isolate. Immunologic and behavioral variables were compared between late seroconverters and persistently uninfected sex worker controls. HIV-1 CTL epitope responses were present in four of six cases, 5-18 months before seroconversion, and their presence was confirmed by bulk CTL culture. A possible viral escape mutation was found in one of six epitopes. The key epidemiologic correlate of late seroconversion was a reduction in sex work over the preceding year. In persistently uninfected controls, a break from sex work was associated with a loss of HIV-specific CD8+ responses. Late seroconversion may occur in HIV-1-resistant sex workers despite preceding HIV-specific CD8+ responses. Seroconversion generally occurs in the absence of detectable CTL escape mutations and may relate to the waning of HIV-specific CD8+ responses due to reduced antigenic exposure.

Traditional antimalarial phytotherapy remedies used by the Kwale community of the Kenyan Coast.

In Kenya, most people especially in rural areas use traditional medicine and medicinal plants to treat many diseases including malaria. Malaria is of national concern in Kenya, in view of development of resistant strains of Plasmodium falciparum to drugs especially chloroquine, which had been effective and affordable. There is need for alternative and affordable therapy. Many antimalarial drugs have been derived from medicinal plants and this is evident from the reported antiplasmodial activity. The aim of the study was to document medicinal plants traditionally used to treat malaria by the Digo community of Kwale district. Traditional health practitioners were interviewed with standardized questionnaires in order to obtain information on medicinal plants traditionally used for management of malaria. Twenty-five species in 21 genera and 16 families were encountered during the study. Celestraceae, Leguminosae and Rubiaceae families represented the species most commonly cited. Three plant species, namely; Maytenus putterlickioides, Warburgia stuhlmannii and Pentas bussei are documented for the first time for the treatment of malaria.

Antimalarial activity of some plants traditionally used in treatment of malaria in Kwale district of Kenya.

Methanolic and water extracts of five medicinal plant species used for treatment of malaria in traditional/cultural health systems of Kwale people in Kenya were tested for antimalarial activity against Plasmodium falciparum and Plasmodium berghei, respectively and for their cytotoxic effects. The most active extracts (IC(50)<10 microg/ml) screened against chloroquine (CQ) sensitive (D6) and resistant (W2) P. falciparum clones, were the water and methanol extracts of Maytenus undata (Thunb.) Blakelock (Celasteraceae), methanol extracts of Flueggea virosa (Willd.) Voigt (Euphorbiaceae), Maytenus putterlickioides (Loes.) Excell and Mendoca (Celastraceae), and Warburgia stuhlmannii Engl. (Canellaceae). These extracts showed various cytotoxic levels on Vero E6 cells with the water extract of M. undata exhibiting least cytotoxicity. At least one of the extracts of the plant species exhibited a high chemo suppression of parasitaemia >70% in a murine model of P. berghei infected mice. These results indicate that there is potential for isolation of a lead compound from the extracts of the five plants. W. stuhlmannii and M. putterlickioides have not been reported before for antiplasmodial activity.

Microsatellite typing reveals strong genetic structure of Schistosoma mansoni from localities in Kenya.

Genetic diversity and population structure of seven populations of Schistosoma mansoni sampled in Kenya were assessed using five microsatellite markers. The mean number of alleles per locus, expected heterozygosity in Hardy-Weinberg equilibrium and pairwise F(ST) values ranged from 5.2 to 10.7, 0.5-0.8 and 3.6-27.3%, respectively. These data reveal that S. mansoni populations in Kenyan have relatively high levels of genetic diversity and is significantly differentiated. Our data combined with information on biogeography support the hypothesis that the strong genetic structure in Kenyan schistosomes is as a result of limited gene flow and large population sizes. Resistance to anthelminthics has not been reported among the Kenyan schistosomes, we hypothesize that this is probably due to the very little gene flow among populations, thereby limiting opportunities for the spread of rare alleles that might confer resistance to the drugs.

New insights into HIV-1 specific cytotoxic T-lymphocyte responses in exposed, persistently seronegative Kenyan sex workers.

A clearer understanding of HIV-1 specific immune responses in highly-exposed, persistently seronegative (HEPS) subjects is important in developing models of HIV-1 protective immunity. HIV-1 specific cytotoxic T-lymphocytes (CTL) have been described in a cohort of HEPS Kenyan sex workers, and recent work has further elucidated these responses. CTL specific for HIV-1 Env were found in the blood of over half the sex workers meeting criteria for HIV resistance, and in some women recognized unmapped epitopes. The proportion of women with Env-specific CTL increased with the duration of uninfected HIV exposure, suggesting that these responses were acquired over time. CD8+ lymphocyte responses directed against predefined HIV-1 CTL epitopes from various HIV-1 genes were found in the blood and genital tract of >50% resistant sex workers, at a ten-fold lower frequency than in infected subjects. The epitope specificity of CD8+ responses differs between HEPS and HIV infected women, and in HEPS the maintenance of responses appears to be dependent on persistent HIV exposure. Several HIV-1 'resistant' sex workers have become HIV infected over the past 6 years, possibly related to waning of pre-existing HIV-specific CTL, and infection has often been associated with a switch in the epitope specificity of CD8+ responses. These findings suggest that vaccine-induced protective HIV immunity is a realistic goal, but that vaccine strategies of boosting or persistent antigen may be necessary for long-lived protection.

Naturally occurring IgG anti-HLA alloantibody does not correlate with HIV type 1 resistance in Nairobi prostitutes.

In an effort to identify an immunological basis for natural resistance to HIV-1 infection, we have examined serum antibody responses to HLA class I antigens in female prostitutes of the Nairobi Sex Workers Study. Anti-HLA antibodies are known to block HIV infectivity in vitro and can be protective against SIV challenge in macaques immunized with purified class I HLA. Thus, it was postulated that broadly cross-reactive alloantibodies recognizing common HLA alleles in the client population might contribute to the prevention of heterosexual transmission of HIV. In fact, 12% of the women were found to have serum IgG antibodies against class I alloantigens. However, this alloantibody did not correlate with the HIV status of the women and was found in a similar proportion of HIV-positive and HIV-resistant women. The observed levels of alloantibody did not increase with HIV infection in susceptible individuals, suggesting that potential antigenic mimicry between HIV and host HLA class I antigens does not significantly increase levels of anti-class I antibodies. The lack of correlation between serum anti-allo-class I HLA antibodies and the risk of sexual transmission indicates that this humoral immune response is unlikely to be the natural mechanism behind the HIV-resistance phenotype of persistently HIV-seronegative women. This result, however, does not preclude the further investigation of alloimmunization as an artificial HIV immunization strategy.

PCR amplification of RoTat 1.2 VSG gene in Trypanosoma evansi isolates in Kenya.

A direct card agglutination test for Trypanosoma evansi, CATT/T. evansi based on the predominant variable antigen-type (pVAT) RoTat 1.2 was evaluated previously in the field in Isiolo District, Kenya. Sixteen out of 51 (31.4%) parasitologically positive camels were negative by the antibody detection test. In the present study, trypanosomes isolated from the camels were analysed in an attempt to determine the cause of the false negative results of CATT/T. evansi. A total of 20 field isolates comprised 16 stocks from camels that were negative by CATT/T. evansi, and 4 from CATT/T. evansi-positive camels. In addition, 15 known T. evansi and four T. brucei were used as reference. Purified DNA samples were tested using an established RoTat 1.2-based polymerase chain reaction (PCR) that yields a 488 bp product for the specific detection of T. evansi. Antibodies to RoTat 1.2 variant surface glycoprotein (VSG) were used in Western blotting to detect RoTat 1.2 VSG linear epitopes. Results of PCR and Western blot showed that the 16 stocks isolated from CATT/T. evansi-negative camels fell into three groups. In Group 1, both the RoTat 1.2 VSG gene and the VSG were absent in three stocks. In five trypanosome stocks in Group 2, the RoTat 1.2 VSG gene was detected, but Western blot was negative indicating absence of the expressed VSG. Five other stocks containing the RoTat 1.2 VSG gene were also in this group. The RoTat 1.2 VSG gene was detected and Western blot was positive in all four trypanosome stocks in Group 3. All four stocks from CATT/T. evansi-positive camels contained the RoTat 1.2 VSG gene and the expressed VSG. The reference T. evansi KETRI 2479 lacked the RoTat 1.2 VSG gene and there was no immune reactivity detected by Western blot. The rest of the reference T. evansi stocks examined contained the RoTat 1.2 VSG gene. All the four T. brucei samples examined were negative by PCR and Western blot. In conclusion, this study showed that the RoTat 1.2 VSG gene was absent from some T. evansi trypanosomes in Kenya.

Evaluation of antigen and antibody rapid detection tests for Trypanosoma evansi infection in camels in Kenya.

The card agglutination test for Trypanosoma evansi (CATT/T. evansi) for the detection of antibodies, and Suratex for the detection of circulating antigens were compared in a cross-sectional study involving camels in eastern and central parts of Kenya. Of the 2227 camels screened, 2038 were owned by nomadic pastoralists in T. evansi endemic areas in eastern Kenya. A herd of 86 camels were from a ranch in Mugwoni. In Athi River area, 35 camels belonged to Kenya Trypanosomiasis Research Institute, and 68 were slaughter animals. Diagnostic sensitivity estimates were obtained by testing sera from 51 camels that had been found to be parasitologically positive by the haematocrit centrifugation technique, buffy-coat technique and mouse inoculation. Diagnostic specificity was estimated by testing sera from 35 camels known to be trypanosome-free. Positive and negative predictive values (NPVs) were calculated using a range of prevalence values. The sensitivity of CATT/T. evansi (68.6%) was higher than that of Suratex (58.8%), but not significantly. Both tests had equally high specificity (100%). The overall prevalence was 2.3% (51 out of 2227) by parasite detection, 32.2% (327 out of 1017) by CATT/T. evansi and 19.6% (188 out of 961) by Suratex. Overall, there was a positive association between CATT/T. evansi and Suratex though the strength of association was low (McNemar's test=46.12, P=0.001; kappa=0.26, CI: 0.20-0.33). Parasite prevalence ranged from 0% in several herds to 27.8% in a herd in Isiolo. Prevalence was highest in Isiolo with 2.5% (51 out of 2030) by parasitological detection, 38.8% (321 out of 828) by CATT/T. evansi and 21.9% (169 out of 772) by Suratex. In Mugwoni prevalence was 7 and 18% by CATT/T. evansi and Suratex, respectively, and no parasites were detected. In Athi River Suratex detected 2.9% (3 out of 103) positive while CATT/T. evansi and parasitological methods gave negative results. At prevalence values between 10 and 100%, CATT/T. evansi as well as Suratex had infinitely high positive predictive values, whereas Suratex had a lower NPV than CATT/T. evansi. In conclusion, results of this study showed that CATT/T. evansi and Suratex were able to detect aparasitaemic infections rapidly and were more sensitive than parasitological methods in revealing the true extent of trypanosomosis in a herd. The tests effectively complemented parasitological methods in the detection of T. evansi infections in camels.

In vitro antiplasmodial activity of some plants used in Kisii, Kenya against malaria and their chloroquine potentiation effects.

Fifty-five organic and aqueous extracts of 11 plants used in malaria therapy in Kisii District, Kenya were tested in vitro against chloroquine (CQ)-sensitive and resistant strains of Plasmodium falciparum. Of the plants tested, 73% were active (IC(50) < 100 microg/ml). Three plants, Vernonia lasiopus, Rhamnus prinoides and Ficus sur afforded extracts with IC(50) values ranging less than 30 microg/ml against both CQ-sensitive and resistant strains. Combination of some extracts with CQ against the multi-drug resistant P. falciparum isolate V1/S revealed some synergistic effect. The plant extracts with low IC(50) values may be used as sources for novel antimalarial compounds to be used alone or in combination with CQ.

Mass antimicrobial treatment in pregnancy. A randomized, placebo-controlled trial in a population with high rates of sexually transmitted diseases.

Sexually transmitted diseases (STDs) are highly prevalent in pregnant women in many developing countries and have been associated with poor obstetric outcomes. Case detection and treatment of STDs in women is problematic and expensive, underscoring the need for other strategies. To explore the potential benefits of routine antimicrobial therapy on pregnancy outcome, we carried out a randomized, double-blind, clinical trial in one of the antenatal clinics in Nairobi, Kenya. Four hundred pregnant women between 28 and 32 weeks' gestation were given a single dose of 250 mg ceftriaxone intramuscularly or a placebo. There was a significant difference between ceftriaxone and placebo-treated women in infant birth weight (3,209 versus 3,056 g, P = .01). In addition, there was a trend toward lower rates of birth weight < 2,500 g (4.0% versus 9.2%, P = .08) and postpartum endometritis (3.8% versus 10.4%, P = .05) in the intervention than in the placebo group. Neisseria gonorrhoeae was isolated from the cervixes of postpartum women in 1.8% of the intervention group as compared to 4.2% of the control group. These data suggest a beneficial effect of antimicrobial prophylaxis on pregnancy outcome. Larger studies should be carried out to examine the public health impact of this intervention.