Efficacy and safety of an artesunate/mefloquine combination, (artequin) in the treatment of uncomplicated P. falciparum malaria in Kenya.

BACKGROUND: Although artesunate and mefloquine have been used as monotherapies in the treatment of malaria in Kenya for a long time, there is insufficient data on the clinical outcome when used as combination therapy in this population. OBJECTIVE: To derive data on the efficacy and safety profile of artesunate-mefloquine combination in the treatment of uncomplicated Plasmodium falciparum malaria in Kenya. DESIGN: An open label single arm clinical trial. SETTING: Bungoma district Hospital. Study area was Bungoma District of Kenya, an endemic area of malaria. The study was conducted between January 2004 and April 2004. SUBJECTS: A total of 200 males and females with uncomplicated plasmodium falciparum malaria weighing 35kg and above were recruited in the study. RESULTS: In the evaluable patient population the day 28 cure rate was 98.4% while day 14 and 7 cure rates were 98.4% and 99.2% respectively. There was rapid relief of symptoms the median time of fever clearance was one day and the most common drug related adverse events were headache dizziness and asthenia. There was no significant derangement in the haematological, biochemical and ECG parameters in the patients on treatment. CONCLUSION: Artesunate-mefloquine combination given simultaneously was found to be highly effective and safe in the treatment of uncomplicated malaria.

Use of rapid and conventional testing technologies for human immunodeficiency virus type 1 serologic screening in a rural Kenyan reference laboratory.

We report a prospective comparison of human immunodeficiency virus type 1 testing by enzyme immunoassay and Western blot with four rapid tests of 486 subjects performed in rural Kenya. Rapid test sensitivity was 100%. Specificity ranged from 99.1 to 100%. Combined use of two Food and Drug Administration-approved rapid tests yielded a single false-positive result.

Detection of high frequencies of HIV-1 cross-subtype reactive CD8 T lymphocytes in the peripheral blood of HIV-1-infected Kenyans.

OBJECTIVES: To quantitate rapidly the frequency of HIV-1 subtype-specific and broadly HIV-1 cross-subtype-reactive CD8 T cells in the peripheral blood of HIV-1-infected individuals from a geographical region of multiple subtype endemicity. METHODS: Autologous B-lymphoblastoid cell lines infected with recombinant vaccinia-viruses expressing gag, env and nef gene products from HIV-1 subtypes A-H were used as antigen-presenting cells to stimulate CD8 T cells from cryopreserved peripheral blood mononuclear cells. Cross-subtype and subtype-specific CD8 cell responses were assessed by flow cytometry for the upregulation of IFN-gamma gene expression in specifically activated CD8 T cells. RESULTS: Strikingly high frequencies of circulating CD8 T cells (up to 11.3% of peripheral CD8 T cells) with specificity for HIV-1 were detectable using this methodology. Both subtype-specific and broadly cross-subtype-reactive CD8 T cells were detected as assessed by IFN-gamma production after stimulation. The pattern of cross-subtype reactivity appeared to be random when the results were assessed as a population, but analysis of the full-length sequence of the infecting virus for each individual showed some skewing of the CD8 cell response towards the infecting subtype. CONCLUSION: High frequencies of HIV-1 cross-subtype-reactive peripheral CD8 T cells can be detected in individuals from a multiple subtype endemic region, providing an incentive for vaccine advancement in such locations. The future assessment of the subtype specificity of cellular immune responses requires full-length sequencing of the infecting virus in conjunction with a comprehensive analysis of phenotypic and functional parameters.

Forty-one near full-length HIV-1 sequences from Kenya reveal an epidemic of subtype A and A-containing recombinants.

OBJECTIVE: To further define the genetic diversity of HIV-1 in Kenya using approaches that clearly distinguish subtypes from inter-subtype recombinants. DESIGN: Near full genome sequencing and analysis were used, including sensitive new tools for detection and mapping of recombinants. METHODS: Purified peripheral blood mononuclear cell DNA from 41 HIV-1 positive blood donations collected from six hospitals across southern Kenya was used to amplify near full-length genomes by nested PCR. These were sequenced on an ABI 3100 automated sequencer and analyzed phylogenetically. RESULTS: Among 41 near full-length genomes, 25 were non-recombinant (61%) and 16 were recombinant (39%). Of the 25 pure subtypes, 23 were subtype A, one was subtype C and one was subtype D. Most recombinants consisted of subtype A and either subtype C or subtype D; a few contained A2, a recently identified sub-subtype. Two A2/D recombinants had identical breakpoints and may represent a circulating recombinant form. A third A2/D recombinant had the same structure as a previously described Korean isolate, and these may constitute a second A2-containing circulating recombinant form. CONCLUSIONS: In Kenya, 93% of HIV-1 genomes were subtype A or A-containing recombinant strains. Almost 40% of all strains were recombinant. Vaccine candidates tested in Kenya should be based on subtype A strains, but the methods used for evaluation of breakthrough infections during future vaccine trials should be capable of identifying non-A subtypes, the A2 sub-subtype, and recombinants.

Evaluation of a standardized direct agglutination test (DAT) for the diagnosis of visceral leishmaniasis in Kenya.

A prototype test kit being developed, by the World Health Organization (WHO), for the diagnosis of visceral leishmaniasis (VL) was evaluated in the Baringo district of Rift Valley province in Kenya. The screening of approximately 10,000 individuals for the signs of VL produced 305 suspected cases. These cases and 304 controls matched for sex and age (+/- 2 years) were then tested with the kit, which is based on a direct agglutination test (DAT). The evaluation was a three-stage process. The first stage, the field screening, involved screening filter-paper samples of dried blood from the suspects and controls at a DAT titre of 1:500. The second stage, the laboratory titration, involved screening of the same individuals by testing freshly eluted filter-paper samples at 1:500 to 1:2000 dilution. In the third stage, the full-scale titration, all samples that had been positive at 1:2000 were titrated at 1:500-1:512,000. All the suspects giving DAT titres of 1:2000 or higher were considered positive for VL. This diagnosis was checked, whenever possible, by the examination of smears and/or cultures of splenic aspirates for leishmanial parasites. Those found to be parasitologically positive were put on a standard treatment regime of 20 mg sodium stibogluconate (Pentostam)/kg.day. Although 42 (13.8%) of the 305 clinical suspects investigated were DAT-positive (at 1:2000), it was only possible to take splenic aspirates from 32. Four (12.5%) of these 32 were apparently false-positives by DAT, as no parasites could be detected in their splenic aspirates. The others provided positive smears and cultures (27 cases) or a negative smear but a positive culture (one case). It was possible to re-examine two of the four serologically positive but parasitologically negative VL suspects at a 3-month follow-up: neither had a palpable spleen, one had seroconverted and the other had much lower DAT titre (1:32,000) than when investigated previously (1:128,000). All the parasitologically confirmed cases remained DAT-positive (1:2000) at this follow-up. The low cut-off titre (1:2000) and the simple procedure should make the kit suitable for use by health workers at all levels of primary-health care, including those with limited training and skills, for screening rural communities at risk of VL.

A diagnostic ELISA for visceral leishmaniasis, based on antigen from media conditioned by Leishmania donovani promastigotes.

Leishmania donovani promastigotes were cultured in a protein-free medium for 3-5 days and the spent medium used to prepare antibody-detection ELISA plates. When the plates were used to test 29 Kenyan and 16 Nepalese patients with visceral leishmaniasis (VL; kala-azar), all the sera collected at diagnosis were found to have high levels of parasite-specific IgG. The levels of these antibodies dropped 6-12 months post-initiation of antileishmanial therapy in all but one of the patients. Although the levels in sera from 59% of the treated patients fell to those measured in sera from healthy controls, those in sera from 17% of the patients did not drop below those seen at diagnosis. The antigen used did not cross-react with sera from patients with parasitological diagnosis of malaria, filariasis, African trypanosomiasis or echinococcosis. Antibodies to antigens in the spent medium were detected, by western blot, in all the sera from Nepalese patients with VL. Promastigote-conditioned media could be the source of cheap antigen for the immunodiagnosis of leishmaniasis.

Efficacy and safety of liposomal amphotericin B (AmBisome) for visceral leishmaniasis in endemic developing countries.

Reported are the results of a study to determine the efficacy and safety of liposomal amphotericin B (AmBisome) for treating visceral leishmaniasis (kala-azar) in several developing countries where the disease is endemic (Brazil, India, and Kenya). At each study site, sequential cohorts of 10 patients each were treated with AmBisome at a dose of 2 mg.kg-1.day-1 (2 MKD). The first cohort received regimen 1:2 MKD on days 1-6 and day 10 (total dose: 14 mg/kg). If the efficacy with this regimen was satisfactory, a second cohort received regimen 2:2 MKD on days 1-4 and 10 (total dose: 10 mg/kg); and a third cohort received regimen 3:2 MKD on days 1, 5, and 10 (total dose: 6 mg/kg). In India, regimens 1, 2, and 3 (which were studied concurrently) each cured 100% of 10 patients. In Kenya, regimen 1 cured all 10 patients, regimen 2 cured 90% of 10 patients, but regimen 3 cured only 20% of 5 patients. In Brazil, regimen 1 was only partially curative: 5 of 13 patients (62%). Therefore, 15 patients were administered regimen 4 (2 MKD for 10 consecutive days; total dose, 20 mg/kg) and 13 patients were cured (83%). These results suggest that for the treatment of kala-azar the following doses of AmBisome should be administered: in India and Kenya, 2 mg/kg on days 1-4 and day 10; and in Brazil, 2 mg/kg on days 1-10.

PIP: The efficacy and safety of liposomal amphotericin B (AmBisome) for the treatment of visceral leishmaniasis (kala-azar) were evaluated in a phase II clinical trial conducted in Brazil, India, and Kenya--countries where kala-azar is endemic. At each study site, sequential cohorts of 10 patients each received three different dosage regimens of AmBisome. The first cohort received 2 mg/kg/day (MKD) on days 1-6 and day 10 (total dose, 14 mg/kg). If the efficacy of this regimen was satisfactory, the second cohort received 2 MKD on days 1-4 and day 10 (total dose, 10 mg/kg) and a third cohort was administered 2 MKD on days 1, 5, and 10 (total dose, 6 mg/kg). In India, all three regimens (studied concurrently) cured 100% of the total of 30 patients. In Kenya, the first regimen cured all 10 patients (100%), the second cured 9 of 10 patients (90%), and the third cured only 1 of 5 patients (20%). In Brazil, since the first regimen cured only 5 of 13 patients (62%), the next 15 patients were given 2 MKD for 10 consecutive days (total dose, 20 mg/kg); this intensified regimen cured 13 of the 15 patients (83%). Adverse effects were minor, primarily fever and chills associated with infusion and irregular pulse. These findings suggest that leishmaniasis patients in India and Kenya should receive 2 mg/kg of AmBisome on days 1-4 and day 10, while those in Brazil should be given 2 mg/kg on days 1-10. AmBisome treatment is especially recommended for those for whom standard agents are likely to be ineffective, toxic, or difficult to administer.

Acute phase protein concentrations predict parasite clearance rate during therapy for visceral leishmaniasis.

Visceral leishmaniasis (VL) remains a major health problem in Kenya and other parts of Africa, Central America and Asia. Currently, splenic aspirate smear and culture are the standard methods of monitoring therapy and relapse. Acute phase reactant markers, C-reactive protein (CRP), serum amyloid A protein (SAA) and alpha 1-acid glycoprotein (AGP) were evaluated as less invasive techniques for monitoring therapy in 59 patients with VL before, during and after therapy. CRP, SAA and AGP were elevated in VL patients at admission and the concentrations decreased with effective therapy to reach normal levels by the end of therapy (SAA and AGP) or by 3 months follow-up (CRP). Two groups of patients were selected on the basis of rate of parasite clearance. The acute phase protein concentrations were significantly raised in those slower to clear parasites. Analysis of sensitivity and specificity of acute phase proteins as predictors of parasite clearance suggested that they might represent useful non-invasive markers for monitoring disease activity, response to therapy and relapse in VL.

Problems in the treatment of kala-azar: case report.

Frequent relapses after treatment for visceral leishmaniasis and apparent parasitological cure is not commonly reported. Seven year old boy who relapsed four times with clinical and parasitological evidence of the disease at each two months follow-up period is presented. He had Leishimania donovani Kenya strain. After treatment, review would be after two months, six months and twelve months periods. Splenic aspirates were routinely done weekly and on the last day of each treatment. The drugs administered for varying periods included intravenous sodium stibogluconate 20 mg/kg daily, P20 in combination with allopurinol 21 mg/kg three times daily, and Pentamidine 4 mg/kg three times weekly and antituberculous drugs. The presence of abundant extra cellular leishmania donovani bodies in the bone marrow and possible pulmonary tuberculosis might have precipitated the frequent relapses. It is not clear which of the drugs effected the cure. It was observed that inspite of prolonged antileishmanial drug administration no side effects were noted.

Phase 2 efficacy trial of an oral 8-aminoquinoline (WR6026) for treatment of visceral leishmaniasis.

The efficacy of an oral 8-aminoquinoline (8-[[6-(diethylamino)hexyl]amino]-6-methoxy-4-methylquinoline) (WR6026) in the treatment of 16 patients with kala azar was evaluated. The first 8 patients received therapy for 2 weeks at a dosage of 0.75-1.00 mg/(kg.d); 1 patient was cured, and in regard to the other 7, a 1-logarithm decrease in the number of splenic parasites and clinical improvement were noted. The next 8 patients received therapy for 4 weeks at the same daily dosage (1 mg/[kg.d]); 4 were cured, and for the other 4, 1- to 2-log decreases in the number of parasites and clinical improvement (in regard to weight, liver and spleen size, hemoglobin level, and leukocyte count) were noted. The therapy was associated with minimal toxicity; adverse effects included gastrointestinal distress, headache, and methemoglobinemia. The fact that one-half of the patients were cured indicates that future trials with longer regimens and higher dosages are warranted and should include patients for whom existing treatment methods have failed.

Relationship between direct agglutination test and splenic aspirate smear parasite load in visceral leishmaniasis at Baringo District, Kenya.

Direct agglutination test was carried out in Baringo District on 100 persons presenting with signs and symptoms suggestive of visceral leishmaniasis. Splenic aspirate smears and cultures were done on these 100 persons in order to parasitologically confirm the findings of the direct agglutination test. It was found that the direct agglutination test positively detected all 79 (79%) patients parasitologically confirmed to have visceral leishmaniasis. Irrespective of the splenic aspirate smear parasite rate, whether 1+ or 6+ on a logarithmic scale, direct agglutination test was positive. There were 21% false positives, two of whom had Schistosoma mansoni in their stools. It was not immediately known about the cause of the other false positives. It was concluded that the direct agglutination test is a good provisional serodiagnostic test for visceral leishmaniasis and should be considered for wider field application.

Is one year follow-up justified in kala-azar post-treatment?

Sixty-five patients, 51 males and 14 females, with clinical and parasitological evidence of visceral leishmaniasis were initially treated as follows: 44.6% were on intravenous sodium stibogluconate (pentostam) 20 mg/kg/d for 30 days, 35.4% was on a combination of pentostam as above and allopurinol 21 mg/kg/d in three divided doses for 30 days while 20% was on pentostam 10 mg/kg thrice/d intravenously for 10 days. All patients were parasitologically negative by the end of their respective treatment regimen. All patients were reviewed at 2 months, 6 months, and 12 months periods in order to evaluate the relapse rates and optimal follow-up period. Thirteen patients (20%) relapsed at 2 months and one patient (1.5%) relapsed at 6 months follow-up periods respectively. There was no relapse between 6 months and 12 months follow-up period. The mean liver and spleen sizes in responders showed a dramatic reduction at 2 months follow-up and thereafter a gradual reduction occurred in the next 10 months. Weight gain continued throughout the year. Apart from platelet count which showed a sustained high level from discharge to 12 months follow-up, the peripheral blood indices stabilized from 2 months follow-up. Relapses were retreated until parasitologically negative twice and then followed up, for a period of 12 months. At follow-up the liver and spleen sizes reduced gradually in the next 12 months.(ABSTRACT TRUNCATED AT 250 WORDS)

The efficacy and safety of ketoconazole in visceral leishmaniasis.

This study was an open evaluation of the efficacy and safety of Ketoconazole, 15 mg/kg/day orally for 3 weeks in 7 evaluable patients with Visceral Leishmaniasis in Kenya. Of all the seven patients who received ketoconazole, none had appreciable clearance of parasites from the splenic aspirate smears that were microscopically examined. All the splenic aspirate cultures done on these patients in the three weeks remained positive for leishmania parasites. Splenic sizes of these patients generally remained unchanged throughout the study period. The mean haemoglobin at the start of treatment was not different from that at the end of treatment. Liver function tests throughout treatment remained unchanged, i.e. within normal limits. It is concluded that Ketoconazole, 15 mg/kg/day orally given to these patients was not effective as an antileishmania drug although there was a one log drop in the parasite load. However, no serious side effect were noted in all of the patients during treatment.

Immunoglobulin G subclass responses to mycobacterial lipoarabinomannan in HIV-infected and non-infected patients with tuberculosis.

Immunoglobulin G subclass responses to lipoarabinomannan (LAM) of Mycobacterium tuberculosis were determined by ELISA in both HIV-1 antibody positive (n = 31) and negative (n = 43) patients with tuberculosis (TB). Responses were also studied in a group of healthy controls (n = 16) and HIV-1 antibody positive (n = 60) individuals without TB. IgG2 antibodies were the predominant subclass, being present in 25 of 43 non-HIV-infected TB patients (58%) and in 11 of 31 HIV-infected TB patients (35%). However, HIV+ TB patients also showed IgG4 (n = 16; 52%), and IgG1 (n = 4, 13%) responses to LAM, whereas these subclasses were absent in sera from HIV-TB patients. Individuals in both non-tuberculous control groups showed no antibody responses to LAM. The influence of HIV infection on B cell responses to LAM, and possible mechanisms for antibody-mediated regulation of immunity to TB, are explored.

Cohort study of human immunodeficiency virus infection in patients with tuberculosis in Nairobi, Kenya. Analysis of early (6-month) mortality.

Retrospective studies suggest that the mortality rate from HIV-1-associated tuberculosis is greater than that from tuberculosis alone, but it is not clear if this is due to failure of antituberculosis treatment or to the complications of HIV-1 infection. We have carried out a prospective cohort study of patients with tuberculosis in Nairobi, Kenya, to compare mortality rates, risk factors, and causes of death in HIV-1 positive and HIV-1 negative patients. One hundred seven HIV-1 positive and 174 HIV-1 negative patients with tuberculosis attending two tuberculosis treatment centers in Nairobi were enrolled and followed monthly. Mortality was significantly higher in HIV-1 positive than in HIV-1 negative patients within 6 months of the start of antituberculosis treatment after adjustment for age, sex, and education (rate ratio = 3.8; 95% confidence interval, 1.7 to 8.1; p less than 0.001). Most of the excess mortality occurred after the first month of treatment and was due to nontuberculous infections. Predictors for mortality differed greatly between HIV-1 positive and HIV-1 negative patients. Mortality was greater in HIV-1 positive patients treated with a "standard" regimen for tuberculosis than in HIV-1 positive patients receiving a "short-course" regimen (p = 0.08 when adjusted for all independent risk factors). Tuberculosis control programs in developing countries need to implement "short-course" regimens and train health workers to recognize and treat nontuberculous infections to maintain their effectiveness in the face of the HIV epidemic.

A new rural focus of cutaneous leishmaniasis caused by Leishmania tropica in Kenya.

We have identified a new rural focus of cutaneous leishmaniasis caused by Leishmania tropica in Muruku sublocation, Salama location, Laikipia district, Rift Valley province, Kenya. Based on a few available case histories, previous reports of L. tropica in Kenya indicated a tentative geographical distribution. Recently 6 indigenous Kenyans from the new focus, who had never travelled outside Kenya, developed cutaneous lesions on the face and/or extremities found to contain Leishmania by culture and smear. Most of the patients manifested the typical 'urban' dry sore which grew slowly into a nodule measuring 2 x 1 cm to 9.5 x 3 cm, and after some months formed a central crust surrounded by small satellite papules. After treatment with Pentostam (sodium stibogluconate), about 40% of the sores failed to heal completely, either scarring centrally with fulminating papules at the edges and spreading peripherally, or healing but then recrudescing at the edge of the scar. Stationary-phase promastigotes from culture isolates were analysed by cellulose acetate electrophoresis. Isoenzyme profiles of 6 isolates were compared with those of World Health Organization reference strains using 12 enzyme loci; they were indistinguishable from those of 2 L. tropica reference strains. All 6 case sites lay within a radius of 4 km. Several other suspected cases from the same area are being investigated.

Cutaneous hypersensitivity reactions due to thiacetazone in HIV-1 seropositive patients treated for tuberculosis.

The effects of the human immunodeficiency virus (HIV) on tuberculosis management was investigated in 227 patients initially treated with a regimen containing streptomycin, isoniazid, and thiacetazone (STH). 93 of these 227 were HIV-seropositive. 60 patients, of whom 18 were HIV-seropositive, received a regimen consisting of streptomycin, isoniazid, rifampicin, and pyrazinamide (SHRZ) in the initial phase, and thiacetazone and isoniazid (TH) in the continuation phase. Cutaneous hypersensitivity reactions occurred in 22 of 111 (20%) HIV-seropositive patients, and in 2 of 176 (1%) HIV-seronegative patients (RR = 18, 95% CI 4.4-76, p less than 10(-7]. During the first 8 weeks of treatment 18 reactions occurred among the 93 HIV-seropositive patients on STH, whereas no reaction occurred in 17 HIV-seropositive patients during the initial phase of SHRZ/TH (p = 0.04). None of the 18 HIV-seropositive patients with cutaneous reactions who were subsequently challenged with isoniazid reacted, nor did any of the 10 tested with streptomycin, but 6 of the 7 challenged with thiacetazone reacted. 3 patients (all HIV-positive and with toxic epidermal necrolysis) died as a result of the cutaneous reaction. These results have major implications for tuberculosis control programmes in Africa.

Schistosomiasis caused by Schistosoma mansoni in Baringo District, Kenya: case report.

Schistosomiasis caused by Schistosoma mansoni has not been reported in Baringo District of Rift Valley Province. The intermediate host (Biomphalaria species) though has been reported to occur along the shores of the lakes in this region. Three children from Baringo District were diagnosed to have schistosomiasis caused by S. mansoni by finding ova in their stools. They gave no history of visiting an endemic area. There are many dams being built for land reclamation, creating favourable conditions for the spread of the disease, in presence of the intermediate and definitive host. Studies on the current status of the disease and malacology should be undertaken in order to control the spread of the disease at an early stage.