Mortality trends and risk factors in advanced stage-2 Human African Trypanosomiasis: A critical appraisal of 23 years of experience in the Democratic Republic of Congo.

We conducted a retrospective study on mortality trends and risk factors in 781 naïve cases of advanced stage-2 sleeping sickness admitted between 1989 and 2012 at the National Reference Center for Human African Trypanosomiasis (HAT), Department of Neurology, Kinshasa University, Democratic Republic of Congo (DRC). Death was the outcome variable whereas age, gender, duration of disease, location of trypanosomes in body fluids, cytorachy, protidorachy, clinical status (assessed on a syndromic and functional basis) on admission, and treatment regimen were predictors in logistic regression models run at the 0.05 significance level. Death proportions were 17.2% in the standard melarsoprol schedule (3-series of intravenous melarsoprol on 3 successive days at 3.6 mg/kg/d, with a one-week interval between the series, ARS 9); 12.1% in the short schedule melarsoprol (10 consecutive days of intravenous melarsoprol at 2.2 mg/kg/d, ARS 10), 5.4% in the first-line eflornithine (14 days of eflornithine at 400 mg/kg/d in 4 infusions a day DFMO B), 9.1% in the NECT treatment regimen (eflornithine for 7 days at 400, mg/kg/d in 2 infusions a day combined with oral nifurtimox for 10 days at 15 mg/kg/d in 3 doses a day); and high (36%) in the group with select severely affected patients given eflornithine because of their clinical status on admission, at the time when this expensive drug was kept for treatment of relapses (14 days at 400 mg/kg/d in 4 infusions a day, DFMO A). After adjusting for treatment, death odds ratios were as follows: 10.40 [(95% CI: 6.55-16.51); p = .000] for clinical dysfunction (severely impaired clinical status) on admission, 2.14 [(95% CI: 1.35-3.39); p = .001] for high protidorachy, 1.99 [(95% CI: 1.18-3.37); p = .010] for the presence of parasites in the CSF and 1.70 [(95% CI: 1.03-2.81); p = .038] for high cytorachy. A multivariable analysis within treatment groups retained clinical status on admission (in ARS 9, ARS 10 and DFMO B groups) and high protidorachy (in ARS 10 and DFMO B groups) as significant predictors of death. The algorithm for initial clinical status assessment used in the present study may serve as the basis for further development of standardized assessment tools relevant to the clinical management of HAT and information exchange in epidemiological reports.

A sensitive and reproducible in vivo imaging mouse model for evaluation of drugs against late-stage human African trypanosomiasis.

OBJECTIVES: To optimize the Trypanosoma brucei brucei GVR35 VSL-2 bioluminescent strain as an innovative drug evaluation model for late-stage human African trypanosomiasis. METHODS: An IVIS® Lumina II imaging system was used to detect bioluminescent T. b. brucei GVR35 parasites in mice to evaluate parasite localization and disease progression. Drug treatment was assessed using qualitative bioluminescence imaging and real-time quantitative PCR (qPCR). RESULTS: We have shown that drug dose-response can be evaluated using bioluminescence imaging and confirmed quantification of tissue parasite load using qPCR. The model was also able to detect drug relapse earlier than the traditional blood film detection and even in the absence of any detectable peripheral parasites. CONCLUSIONS: We have developed and optimized a new, efficient method to evaluate novel anti-trypanosomal drugs in vivo and reduce the current 180 day drug relapse experiment to a 90 day model. The non-invasive in vivo imaging model reduces the time required to assess preclinical efficacy of new anti-trypanosomal drugs.

The antitumor effects of an arsthinol-cyclodextrin complex in a heterotopic mouse model of glioma.

In this paper, we examined arsthinol-cyclodextrin complexes, which display an anticancer activity. The association constants were 17,502±522 M(-1) for hydroxypropyl-ß-cyclodextrin and 12,038±10,168 M(-1) for randomized methylated ß-cyclodextrin. (1)H NMR experiments in solution also confirmed the formation of these complexes and demonstrated an insertion of the arsthinol (STB) with its dithiarsolane extremity into the wide rim of the hydroxypropyl-ß-cyclodextrin cavity. Complexed arsthinol was more effective than arsenic trioxide (As2O3) and melarsoprol on the U87 MG cell line. Importantly, in the in vivo study, we observed significant antitumor activity against heterotopic xenografts after i.p. administration and did not see any signs of toxicity. This remains to be verified using an orthotopic model.

Safety and efficacy of the 10-day melarsoprol schedule for the treatment of second stage Rhodesiense sleeping sickness.

OBJECTIVE: Assessment of the safety and efficacy of a 10-day melarsoprol schedule in second stage T.b. rhodesiense patients and the effect of suramin-pretreatment on the incidence of encephalopathic syndrome (ES) during melarsoprol therapy. DESIGN: Sequential conduct of a proof-of-concept trial (n = 60) and a utilization study (n = 78) using historic controls as comparator. SETTING: Two trial centres in the T.b. rhodesiense endemic regions of Tanzania and Uganda. PARTICIPANTS: Consenting patients with confirmed second stage disease and a minimum age of 6 years were eligible for participation. Unconscious and pregnant patients were excluded. MAIN OUTCOME MEASURES: The primary outcome measures were safety and efficacy at end of treatment. The secondary outcome measure was efficacy during follow-up after 3, 6 and 12 months. RESULTS: The incidence of ES in the trial population was 11.2% (CI 5-17%) and 13% (CI 9-17%) in the historic data. The respective case fatality rates were 8.4% (CI 3-13.8%) and 9.3% (CI 6-12.6%). All patients discharged alive were free of parasites at end of treatment. Twelve months after discharge, 96% of patients were clinically cured. The mean hospitalization time was reduced from 29 to 13 days (p<0.0001) per patient. CONCLUSIONS: The 10-day melarsoprol schedule does not expose patients to a higher risk of ES or death than does treatment according to national schedules in current use. The efficacy of the 10-day melarsoprol schedule was highly satisfactory. No benefit could be attributed to the suramin pre-treatment. TRIAL REGISTRATION: Current Controlled Trials ISRCTN40537886.

An alternative form of melarsoprol in sleeping sickness.

Human African trypanosomiasis (HAT), or sleeping sickness, is a major threat to human health throughout sub-Saharan Africa. Almost always fatal if untreated or inadequately treated, a commonly used drug for treating late-stage HAT, and the only drug for late-stage Trypanosoma brucei rhodesiense, is intravenous melarsoprol, which kills 5% of patients receiving it. Melarsoprol cyclodextrin inclusion complexes have been tested in a highly reliable mouse model of HAT. These complexes increase the oral bioavailability of melarsoprol making them effective orally and both curative and nontoxic in doses that are equivalent to those of intravenous melarsoprol. It is argued that a small clinical trial of this drug in HAT is justified to potentially improve the outcome of patients with late-stage rhodesiense disease.

Melarsoprol cyclodextrin inclusion complexes as promising oral candidates for the treatment of human African trypanosomiasis.

Human African trypanosomiasis (HAT), or sleeping sickness, results from infection with the protozoan parasites Trypanosoma brucei (T. b.) gambiense or T. b. rhodesiense and is invariably fatal if untreated. There are 60 million people at risk from the disease throughout sub-Saharan Africa. The infection progresses from the haemolymphatic stage where parasites invade the blood, lymphatics and peripheral organs, to the late encephalitic stage where they enter the central nervous system (CNS) to cause serious neurological disease. The trivalent arsenical drug melarsoprol (Arsobal) is the only currently available treatment for CNS-stage T. b. rhodesiense infection. However, it must be administered intravenously due to the presence of propylene glycol solvent and is associated with numerous adverse reactions. A severe post-treatment reactive encephalopathy occurs in about 10% of treated patients, half of whom die. Thus melarsoprol kills 5% of all patients receiving it. Cyclodextrins have been used to improve the solubility and reduce the toxicity of a wide variety of drugs. We therefore investigated two melarsoprol cyclodextrin inclusion complexes; melarsoprol hydroxypropyl-ß-cyclodextrin and melarsoprol randomly-methylated-ß-cyclodextrin. We found that these compounds retain trypanocidal properties in vitro and cure CNS-stage murine infections when delivered orally, once per day for 7-days, at a dosage of 0.05 mmol/kg. No overt signs of toxicity were detected. Parasite load within the brain was rapidly reduced following treatment onset and magnetic resonance imaging showed restoration of normal blood-brain barrier integrity on completion of chemotherapy. These findings strongly suggest that complexed melarsoprol could be employed as an oral treatment for CNS-stage HAT, delivering considerable improvements over current parenteral chemotherapy.

Isolation of Trypanosoma brucei gambiense from cured and relapsed sleeping sickness patients and adaptation to laboratory mice.

BACKGROUND: Sleeping sickness due to Trypanosoma brucei (T.b.) gambiense is still a major public health problem in some central African countries. Historically, relapse rates around 5% have been observed for treatment with melarsoprol, widely used to treat second stage patients. Later, relapse rates of up to 50% have been recorded in some isolated foci in Angola, Sudan, Uganda and Democratic Republic of the Congo (DRC). Previous investigations are not conclusive on whether decreased sensitivity to melarsoprol is responsible for these high relapse rates. Therefore we aimed to establish a parasite collection isolated from cured as well as from relapsed patients for downstream comparative drug sensitivity profiling. A major constraint for this type of investigation is that T.b. gambiense is particularly difficult to isolate and adapt to classical laboratory rodents. METHODOLOGY/PRINCIPAL FINDINGS: From 360 patients treated in Dipumba hospital, Mbuji-Mayi, D.R. Congo, blood and cerebrospinal fluid (CSF) was collected before treatment. From patients relapsing during the 24 months follow-up, the same specimens were collected. Specimens with confirmed parasite presence were frozen in liquid nitrogen in a mixture of Triladyl, egg yolk and phosphate buffered glucose solution. Isolation was achieved by inoculation of the cryopreserved specimens in Grammomys surdaster, Mastomys natalensis and SCID mice. Thus, 85 strains were isolated from blood and CSF of 55 patients. Isolation success was highest in Grammomys surdaster. Forty strains were adapted to mice. From 12 patients, matched strains were isolated before treatment and after relapse. All strains belong to T.b. gambiense type I. CONCLUSIONS AND SIGNIFICANCE: We established a unique collection of T.b. gambiense from cured and relapsed patients, isolated in the same disease focus and within a limited period. This collection is available for genotypic and phenotypic characterisation to investigate the mechanism behind abnormally high treatment failure rates in Mbuji-Mayi, D.R. Congo.

Polysomnography as a diagnosis and post-treatment follow-up tool in human African trypanosomiasis: a case study in an infant.

Gambian (Trypanosoma brucei gambiense) human African trypanosomiasis (HAT) evolves from the hemolymphatic stage 1, treated with pentamidine, to the meningoencephalitic stage 2, often treated with melarsoprol. This arseniate may provoke a deadly reactive encephalopathy. It is therefore crucial to diagnose precisely the stages of HAT, especially when clinical and biological examinations are doubtful. We present here the case of a 30-month old girl (E20 KOLNG) diagnosed with stage 1 HAT during a field survey in June 2007 in Congo. She was followed-up every six months for 18 months in a village dispensary facility at Mpouya. Her health status deteriorated in December 2008, although cerebrospinal fluid (CSF) white blood cell (WBC) count was normal. The child was hospitalized at Brazzaville and a daytime polysomnographic recording (electroencephalogram, electrooculogram, and electromyogram) was performed (Temec Vitaport 3® portable recorder) to avoid a new lumbar puncture. The child presented a complete polysomnographic syndrome of HAT with a major disturbance of the distribution of sleep and wake episodes and the occurrence of sleep onset REM periods (SOREMPs). The relapse at stage 2 was confirmed by a new CSF examination that showed an elevated WBC count (23cells·µL(-1)) with the presence of B lymphocytes. Melarsoprol treatment was undertaken. A post-treatment recording was immediately performed, showing the resolution of sleepwake pattern abnormalities. Another polysomnography, taken four months later, confirmed the normalization of sleep-wake patterns indicating healing. We therefore propose that polysomnography, being a non-invasive technique, should be used in children to alleviate burden caused by HAT staging procedures, especially regarding lumbar punctures in remote African villages.

Effectiveness of melarsoprol and eflornithine as first-line regimens for gambiense sleeping sickness in nine Médecins Sans Frontières programmes.

This paper describes the effectiveness of first-line regimens for stage 2 human African trypanosomiasis (HAT) due to Trypanosoma brucei gambiense infection in nine Médecins Sans Frontières HAT treatment programmes in Angola, Republic of Congo, Sudan and Uganda. Regimens included eflornithine and standard- and short-course melarsoprol. Outcomes for 10461 naïve stage 2 patients fitting a standardised case definition and allocated to one of the above regimens were analysed by intention-to-treat analysis. Effectiveness was quantified by the case fatality rate (CFR) during treatment, the proportion probably and definitely cured and the Kaplan-Meier probability of relapse-free survival at 12 months and 24 months post admission. The CFR was similar for the standard- and short-course melarsoprol regimens (4.9% and 4.2%, respectively). The CFR for eflornithine was 1.2%. Kaplan-Meier survival probabilities varied from 71.4-91.8% at 1 year and 56.5-87.9% at 2 years for standard-course melarsoprol, to 73.0-91.1% at 1 year for short-course melarsoprol, and 79.9-97.4% at 1 year and 68.6-93.7% at 2 years for eflornithine. With the exception of one programme, survival at 12 months was >90% for eflornithine, whilst for melarsoprol it was <90% except in two sites. Eflornithine is recommended where feasible, especially in areas with low melarsoprol effectiveness.

High failure rates of melarsoprol for sleeping sickness, Democratic Republic of Congo.

A retrospective chart review of 4,925 human African trypanosomiasis patients treated with melarsoprol in 2001-2003 in Equateur Nord Province of the Democratic Republic of Congo showed a treatment failure rate of 19.5%. This rate increased over the 3 years. Relapse rates were highest in the central part of the province.

Equivalence trial of melarsoprol and nifurtimox monotherapy and combination therapy for the treatment of second-stage Trypanosoma brucei gambiense sleeping sickness.

BACKGROUND: Treatment of second-stage sleeping sickness relies mainly on melarsoprol. Nifurtimox has been successfully used to cure melarsoprol-refractory sleeping sickness caused by Trypanosoma brucei gambiense infection. METHODS: An open, randomized trial was conducted to test for equivalence between the standard melarsoprol regimen and 3 other regimens, as follows: standard melarsoprol therapy (3 series of 3.6 mg/kg/day intravenously [iv] for 3 days, with 7-day breaks between the series); 10-day incremental-dose melarsoprol therapy (0.6 mg/kg iv on day 1, 1.2 mg/kg iv on day 2, and 1.8 mg/kg iv on days 3-10); nifurtimox monotherapy for 14 days (5 mg/kg orally 3 times per day); and consecutive 10-day melarsoprol-nifurtimox combination therapy (0.6 mg/kg iv melarsoprol on day 1, 1.2 mg/kg iv melarsoprol on day 2, and 1.2 mg/kg/day iv melarsoprol combined with oral 7.5 mg/kg nifurtimox twice a day on days 3-10). Primary outcomes were relapse, severe adverse events, and death attributed to treatment. RESULTS: A total of 278 patients were randomized. The frequency of adverse events was similar between the standard melarsoprol regimen and the other regimens. Encephalopathic syndromes occurred in all groups and caused all deaths that were likely due to treatment. Relapses (n=48) were observed only with the 3 monotherapy regimens. CONCLUSION: A consecutive 10-day low-dose melarsoprol-nifurtimox combination is more effective than the standard melarsoprol regimen.

Clinical presentation and treatment outcome of sleeping sickness in Sudanese pre-school children.

BACKGROUND: Existing data on human African trypanosomiasis (HAT) due to Trypanosoma brucei gambiense among children are limited. Here, we described the demographic, clinical, diagnostic, treatment and outcome characteristics of HAT in pre-school children from Kajo-Keji County, South Sudan in comparison with older patients. METHODS: We did a retrospective analysis of HAT patients treated at the Kiri Sleeping Sickness Treatment Centre (SSTC), Kajo-Keji County, from June 2000 to December 2002. RESULTS: Of 1958 HAT patients, 119 (6.1%) were pre-school children (<6 years) including 56 (47%) in first-stage illness and 63 (53%) in second-stage. The proportion of children in second-stage HAT was significantly higher in very young children (<2 years). Walking and speech disturbances were more frequent in second-stage HAT but other neurological symptoms and signs were not associated with disease stage. Pentamidine treatment for first-stage illness was very safe and effective among pre-school children. In contrast, 4.9% of pre-school children in second-stage illness died during melarsoprol treatment and 46% had > or = 1 severe adverse event(s). Macular rash, jaundice and skin necrosis on injection site were significantly more frequent in this age group (p<0.05). Melarsoprol-induced encephalopatic syndrome was less frequent but more severe than in older age groups. CONCLUSION: The clinical features of T. b. gambiense HAT among pre-school children are insufficiently stage-specific. Therefore, laboratory-based staging is mandatory to prevent unnecessary harm to HAT patients caused by the high toxicity of melarsoprol.

Melarsoprol versus eflornithine for treating late-stage Gambian trypanosomiasis in the Republic of the Congo.

OBJECTIVE: To compare the effectiveness of melarsoprol and eflornithine in treating late-stage Gambian trypanosomiasis in the Republic of the Congo. METHODS: We analysed the outcomes of death during treatment and relapse within 1 year of discharge for 288 patients treated with eflornithine, 311 patients treated with the standard melarsoprol regimen and 62 patients treated with a short-course (10-day) melarsoprol regimen between April 2001 and April 2005. FINDINGS: A total of 1.7% (5/288) of patients treated with eflornithine died compared with 4.8% (15/311) of those treated with standard melarsoprol and 6.5% (4/62) of those treated with short-course melarsoprol. Patients treated with eflornithine tended to be younger and were more likely to have trypanosomes or higher white blood cell counts in their cerebrospinal fluid. The cumulated incidence of relapse among patients who attended at least one follow-up visit 1 year after discharge was 8.1% (11/136) for those treated with eflornithine, 14% (36/258) for those treated with standard melarsoprol and 15.5% (9/58) for those treated with shortcourse melarsoprol. In a multivariate analysis, when compared with eflornithine, standard melarsoprol was found to be a risk factor for both death (odds ratio (OR) = 2.87; 95% confidence interval (CI) = 1.03-8.00) and relapse (hazard ratio (HR) = 2.47; 95% CI = 1.22-5.03); when compared with eflornithine, short-course melarsoprol was also found to be a risk factor for death (OR = 3.90; 95% CI = 1.02-14.98) and relapse (HR = 6.65; 95% CI = 2.61-16.94). CONCLUSION: The effectiveness of melarsoprol treatment appears to have diminished. Eflornithine seems to be a better first-line therapy for treating late-stage Gambian trypanosomiasis in the Republic of the Congo.

Randomized controlled trial of three regimens of melarsoprol in the treatment of Trypanosoma brucei gambiense trypanosomiasis.

A total of 389 patients with late-stage Trypanosoma brucei gambiense trypanosomiasis were enrolled in a randomized controlled trial comparing the efficacy and toxicity of three regimens of melarsoprol: regimen A, 3.6 mg/kg (max. 180 mg) for all i.v. injections, given as three series of three injections separated by 1-week intervals; regimen B, 10 consecutive daily i.v. injections of 2.16 mg/kg; or regimen C, three series of three i.v. injections separated by 1-week intervals, but with graded dosing (1.8, 2.16, 2.52, 2.52, 2.88, 3.24, then 3.6 mg/kg for the last three injections). After treatment, patients were followed with half-yearly lumbar punctures for 2 years. During treatment, convulsions were significantly more common in patients allocated to the graded dosing regimen (7/70 [10.0%] vs. 11/319 [3.4%], P = 0.03). The 2-year probability of relapse was 5.4%, 7.4% and 25.0% for regimens A, B and C respectively (P < 0.001). The new regimen of 10 daily injections of melarsoprol was as effective and had the same toxicity as the traditional regimen of three series of three injections at the full dose. Graded dosing, which was associated with a much lower efficacy and more frequent convulsions, should be abandoned.

Trypanosomiasis relapse after melarsoprol therapy, Democratic Republic of Congo, 1982-2001.

Recently, a high proportion of patients with late-stage Trypanosoma brucei gambiense trypanosomiasis, who had been treated with melarsoprol in some disease-endemic areas, subsequently relapsed. To determine whether the frequency of postmelarsoprol relapses increased over time, we reviewed data from 2,221 trypanosomiasis patients treated with melarsoprol during this period in Nioki, Democratic Republic of Congo, from 1982 to 2001. The frequency of relapses was 5.6%(31/553), 6.8%(35/512), 4.5%(18/398), 11.4%(34/299), and 5.0%(17/343) for those treated from 1982 to 1985, 1986 to 1989, 1990 to 1993, 1994 to 1997, and 1998 to 2001, respectively. The higher frequency of relapses in 1994 to 1997 was associated with an incremental dosage regimen of melarsoprol. In multivariate analysis, after adjustment for treatment regimen, sex, residence, and trypanosomes in cerebrospinal fluid, postmelarsoprol relapses did not increase in Nioki, perhaps because 1) little drug pressure exists; 2) subtherapeutic doses have rarely been administered; 3) little potential exists for the preferential transmission of melarsoprol-resistant strains.

Efficacy of 10-day melarsoprol schedule 2 years after treatment for late-stage gambiense sleeping sickness.

In 2000, we reported that a new short treatment schedule of melarsoprol was not worse than the longer and demanding standard treatment for late-stage human African trypanosomiasis. This alternative schedule was assessed in an open, randomised clinical equivalence trial of 500 patients in Angola. 24 h after treatment, all patients were parasite free. Of 442 patients, 12 (3%) had relapsed after 1 year, of whom seven (3%) had had standard treatment and five (2%) the alternative treatment. After 2 years, 23 (5%) relapsing patients were reported, 11 (5%) in the standard treatment group and 12 (6%) in the new group. The results at the 2-year follow-up support and strengthen our previous findings.

Arsenicals (melarsoprol), pentamidine and suramin in the treatment of human African trypanosomiasis.

Human African trypanosomiasis (HAT), otherwise known as sleeping sickness, has remained a disease with no effective treatment. Recent progress in HAT research suggests that a vaccine against the disease is far from being successful. Also the emergence of drug-resistant trypanosomes makes further work in this area imperative. So far the treatment for the early stage of HAT involves the drugs pentamidine and suramin which have been very successful. In the second stage of the disease, during which the trypanosomes reside in the cerebrospinal fluid (CSF), treatment is dependent exclusively on the arsenical compound melarsoprol. This is largely due to the inability to find compounds that can cross the blood brain barrier and kill the CSF-residing trypanosomes. This review summarises our current understanding on the treatment of HAT.

Combination of eflornithine and melarsoprol for melarsoprol-resistant Gambian trypanosomiasis.

OBJECTIVE: To evaluate the efficacy and toxicity of a combination of eflornithine and melarsoprol among relapsing cases of Gambian trypanosomiasis. METHODS: Forty-two late-stage Trypanosoma brucei gambiense trypanosomiasis patients relapsing after initial treatment with melarsoprol were treated with a sequential combination of intravenous eflornithine (100 mg/kg every 6 h for 4 days) followed by three daily injections of melarsoprol (3.6 mg/kg, up to 180 mg). They were then followed-up for 24 months. RESULTS: Two (4.8%) patients died during treatment. Of the 40 surviving patients, two had a treatment failure, 13 and 19 months after having received the combination therapy. By Kaplan-Meier analysis, the 2-year probability of cure was 93.3% (95% confidence interval: 84.3-100%). CONCLUSION: This sequential combination has an efficacy and a toxicity similar to a 7-day course of eflornithine monotherapy, but is easier to administer. Whether such therapeutic success corresponds tosynergism between eflornithine and melarsoprol, or merely means that 4 days of eflornithine monotherapy suffices for such patients, will need to be determined in a comparative trial.