Two-Year Follow-Up of Trypanosoma brucei gambiense Serology after Successful Treatment of Human African Trypanosomiasis: Results of Four Different Sero-Diagnostic Tests.

Gambiense human African trypanosomiasis (gHAT), also known as gambiense sleeping sickness, is a parasitic infection caused by Trypanosoma brucei gambiense. During the last decades, gHAT incidence has been brought to an all-time low. Newly developed serological tools and drugs for its diagnosis and treatment put the WHO goal of interruption of transmission by 2030 within reach. However, further research is needed to efficiently adapt these new advances to new control strategies. We assessed the serological evolution of cured gHAT patients over a two-year period using four different tests: the rapid diagnostic test (RDT) HAT Sero K-SeT, ELISA/T.b. gambiense, Trypanosoma brucei gambiense inhibition ELISA (iELISA), and the immune trypanolysis test. High seropositive rates were observed in all the tests, although sero-reversion rates were different in each test: ELISA/T.b. gambiense was the test most likely to become negative two years after treatment, whereas RDT HAT Sero-K-SeT was the least likely. iELISA and trypanolysis showed intermediate and comparable probabilities to become negative. Stage 1 patients were also noted to be more likely to become negative than Stage 2 patients in all four serological tests. Our results confirm previous findings that trypanosome-specific antibody concentrations in blood may persist for up to two years, implying that HAT control programs should continue to take the history of past HAT episodes into consideration.

Feasibility of a dried blood spot strategy for serological screening and surveillance to monitor elimination of Human African Trypanosomiasis in the Democratic Republic of the Congo.

In recent years, the number of reported Human African Trypanosomiasis (HAT) cases caused by Trypanosoma brucei (T.b.) gambiense has been markedly declining, and the goal of 'elimination as a public health problem' is within reach. For the next stage, i.e. interruption of HAT transmission by 2030, intensive screening and surveillance will need to be maintained, but with tools and strategies more efficiently tailored to the very low prevalence. We assessed the sequential use of ELISA and Immune Trypanolysis (ITL) on dried blood spot (DBS) samples as an alternative to the traditional HAT field testing and confirmation approach. A cross-sectional study was conducted in HAT endemic and previously endemic zones in Kongo Central province, and a non-endemic zone in Haut Katanga province in the Democratic Republic of the Congo (DRC). Door-to-door visits were performed to collect dried blood spot (DBS) samples on filter paper. ELISA/T.b. gambiense was conducted followed by ITL for those testing positive by ELISA and in a subset of ELISA negatives. In total, 11,642 participants were enrolled. Of these, 11,535 DBS were collected and stored in appropriate condition for ELISA testing. Ninety-seven DBS samples tested positive on ELISA. In the endemic zone, ELISA positivity was 1.34% (95%CI: 1.04-1.64). In the previously endemic zone and non-endemic zone, ELISA positivity was 0.34% (95% CI: 0.13-0.55) and 0.37% (95% CI: 0.15-0.60) respectively. Among the ELISA positives, only two samples had a positive ITL result, both from the endemic zone. One of those was from a former HAT patient treated in 2008 and the other from an individual who unfortunately had deceased prior to the follow-up visit. Our study showed that a surveillance strategy, based on DBS samples and centralized testing with retracing of patients if needed, is feasible in DRC. ELISA seems well suited as initial test with a similar positivity rate as traditional screening tests, but ITL remains complex. Alternatives for the latter, also analyzable on DBS, should be further explored.

Community-based survey on helminth infections in Kwilu province, the Democratic Republic of the Congo, and implications for local control strategies.

To adequately plan mass drug administration campaigns, the Democratic Republic of the Congo (DRC) needs further support for the mapping and monitoring of schistosomiasis (SCH) and soil-transmitted helminths (STH). We conducted a community-based survey in the health districts of Mosango and Yasa Bonga of the Kwilu province, DRC. A stratified two-stage cluster random sampling method was used to include participants into three different strata: Preschool-aged children (PSAC), school-aged children (SAC), and adults who were further subdivided into women of reproductive age (WRA) and other adults. In total, surveyors visited 30 villages, and 1 206 individuals participated in the study. Stool samples were collected to perform duplicate Kato-Katz smears for the detection of SCH and STH infection. Hookworm was the most prevalent infection in both districts, 34.1% (95%CI: 32.0-38.4), followed by A. lumbricoides (2.7%; 95%CI: 1.3-2.9) and T. trichiura (1.9%; 95%CI: 1.1-2.7). We did not find any SCH infection. The prevalence of each STH infection was similar across all risk groups, and the majority of the infected individuals was carrying light intensity infection. Compared to SAC, other adults were equally infected with hookworm. The prevalence of STH infection in SAC guides the MDA implementation because schoolchildren are most at risk and easily accessible program targets if school attendance is high. The current treatment strategy targets PSAC, SAC and WRA. However, this study shows that adults in general could also benefit from deworming. Therefore, community-wide preventive chemotherapy would be the most appropriate choice to control the hookworm burden rapidly.

Safety and tolerability of artesunate-amodiaquine, artemether-lumefantrine and quinine plus clindamycin in the treatment of uncomplicated Plasmodium falciparum malaria in Kinshasa, the Democratic Republic of the Congo.

INTRODUCTION: Artemisinin-based combination therapy is currently the best option for the treatment of uncomplicated malaria. Quinine is recommended as a rescue treatment. Safety information during repeated treatment with the same drug is scarce. We report safety data from the Quinact randomized clinical trial (RCT) that was designed to assess efficacy and safety of artesunate-amodiaquine (ASAQ), artemether-lumefantrine (AL) and quinine+clindamycin (QnC). METHODOLOGY: Males and females aged 12 to 59 months with uncomplicated malaria were treated with ASAQ and followed up during 42 days (preRCT). Clinical failures were randomized to one of the 3 treatments and followed up for 28 days (RCT). Subsequent failures were repeatedly treated with ASAQ several times as needed (postRCT1, postRCT2 and so on) until a 28-days follow up period without parasitaemia. RESULTS: Eight hundred and sixty-five, 242 and 64 patients were recruited respectively in preRCT, RCT and postRCTs. In preRCT, 433 (50.0%) patients experienced at least one drug-related adverse event (AE). The most reported AEs were anorexia (22.9%), asthenia (19.4%), and abnormal behavior (14.6%). Twenty-nine AEs (3.5%) were reported to be severe. In RCT, at least one drug-related AE was reported in 54.7%, 21.5% and 40.0% of patient randomized respectively to ASAQ, AL and QnC (p<0.001). During postRCT1 (n = 64), postRCT 2 (n = 17) and postRCT3 (n = 7), respectively 32.8%, 35.3% and 71.4% of patients experienced at least one drug-related AE. Three serious adverse events occurred but not judged related to study medication. CONCLUSION: The proportion of AEs did not increase over the treatment courses with ASAQ. However, continuous monitoring is important.

Dengue and chikungunya among outpatients with acute undifferentiated fever in Kinshasa, Democratic Republic of Congo: A cross-sectional study.

BACKGROUND: Pathogens causing acute fever, with the exception of malaria, remain largely unidentified in sub-Saharan Africa, given the local unavailability of diagnostic tests and the broad differential diagnosis. METHODOLOGY: We conducted a cross-sectional study including outpatient acute undifferentiated fever in both children and adults, between November 2015 and June 2016 in Kinshasa, Democratic Republic of Congo. Serological and molecular diagnostic tests for selected arboviral infections were performed on blood, including PCR, NS1-RDT, ELISA and IFA for acute, and ELISA and IFA for past infections. RESULTS: Investigation among 342 patients, aged 2 to 68 years (mean age of 21 years), with acute undifferentiated fever (having no clear focus of infection) revealed 19 (8.1%) acute dengue-caused by DENV-1 and/or DENV-2 -and 2 (0.9%) acute chikungunya infections. Furthermore, 30.2% and 26.4% of participants had been infected in the past with dengue and chikungunya, respectively. We found no evidence of acute Zika nor yellow fever virus infections. 45.3% of patients tested positive on malaria Rapid Diagnostic Test, 87.7% received antimalarial treatment and 64.3% received antibacterial treatment. DISCUSSION: Chikungunya outbreaks have been reported in the study area in the past, so the high seroprevalence is not surprising. However, scarce evidence exists on dengue transmission in Kinshasa and based on our data, circulation is more important than previously reported. Furthermore, our study shows that the prescription of antibiotics, both antibacterial and antimalarial drugs, is rampant. Studies like this one, elucidating the causes of acute fever, may lead to a more considerate and rigorous use of antibiotics. This will not only stem the ever-increasing problem of antimicrobial resistance, but will-ultimately and hopefully-improve the clinical care of outpatients in low-resource settings. TRIAL REGISTRATION: ClinicalTrials.gov NCT02656862.

Uncomplicated Clinical Malaria Features, the Efficacy of Artesunate-Amodiaquine and Their Relation with Multiplicity of Infection in the Democratic Republic of Congo.

BACKGROUND: In the Democratic Republic of Congo, artesunate-amodiaquine (ASAQ) is the first-line medication recommended for uncomplicated malaria treatment. We conducted a study in Kinshasa to describe the clinical features of the disease and assess the efficacy of ASAQ and its impact on the multiplicity of infection in children with uncomplicated malaria. METHODS: Children aged 12 to 59 months with uncomplicated P. falciparum malaria were treated with ASAQ and followed up passively for 42 days. To distinguish new infections from recrudescent parasites, samples were genotyped using a stepwise strategy with three molecular markers (GLURP, MSP2 and MSP1). We then assessed PCR-corrected and -uncorrected day-42 cure rates and multiplicity of infection (MOI). RESULTS: In total, 2,796 patients were screened and 865 enrolled in the study. Clinical features were characterized by history of fever (100%), coryza (59.9%) and weakness (59.4%). The crude and PCR-corrected efficacies of ASAQ were 55.3% (95%CI: 51.8-58.8) and 92.8% (95%CI: 91.0-94.6) respectively, as 83.6% (95%CI: 79.1-87.2) of the recurrences were new infections. Compared to monoclonal infections, polyclonal infections were more frequent at enrollment (88.1%) and in recurrences (80.1%; p = 0.005; OR: 1.8, 95%CI: 1.20-2.8). The median MOI at enrollment (MOI = 3.7; IQR: 0.7-6.7) decreased to 3 (IQR: 1-5) in the recurrent samples (p<0.001). Patients infected with a single haplotype on day 0 had no recrudescence; the risk of recrudescence increased by 28% with each additional haplotype (HR: 1.3, 95%CI: 1.24-1.44). CONCLUSION: The PCR-corrected efficacy of ASAQ at day 42 was 92.8%, but crude efficacy was relatively poor due to high reinfection rates. Treatment outcomes were positively correlated with MOI. Continued monitoring of the efficacy of ACTs-ASAQ, in this case-is paramount. TRIAL REGISTRATION: ClinicalTrials.gov NCT01374581.

The Challenges of Research Informed Consent in Socio-Economically Vulnerable Populations: A Viewpoint From the Democratic Republic of Congo.

In medical research, the ethical principle of respect for persons is operationalized into the process of informed consent. The consent tools should be contextualized and adapted to the different socio-cultural environment, especially when research crosses the traditional boundaries and reaches poor communities. We look at the challenges experienced in the malaria Quinact trial, conducted in the Democratic Republic of Congo, and describe some lessons learned, related to the definition of acceptable representative, the role of independent witness and the impact of socio-economic vulnerability. To ensure children's protection, consent is required by the parents or, in their absence, by a legally mandated representative. In our setting, children's responsibility is often entrusted permanently or temporarily to relatives or friends without a tribunal mandate. Hence, a notion of 'culturally acceptable representative' under supervision of the local Ethics Committee may be more suitable. To ensure protection of illiterate subjects, an independent witness is required to confirm that the consent was freely given. However, in low-literacy contexts, potential witnesses often don't have any previous relationship with patient and there may be power-unbalance in their relationship, rather than genuine dialogue. In poor communities, trial participation may be seen as an opportunity to secure access to healthcare. Poverty may also lead to 'competition' to access the research-related benefits, with a risk of disturbance at societal or household level. Adjusting consent procedures to sociocultural and socioeconomic realities is essential for fulfilling the underlying ethical principles. This requires a collaborative dialogue between researchers, regulators and ethics committees.

Efficacy and safety of intermittent preventive treatment for malaria in schoolchildren: a systematic review.

BACKGROUND: Intermittent preventive treatment (IPT) is a proven malaria control strategy in infants and pregnancy. School-aged children represent 26 % of the African population, and an increasing percentage of them are scholarized. Malaria is causing 50 % of deaths in this age group and malaria control efforts may shift the malaria burden to older age groups. Schools have been suggested as a platform for health interventions delivery (deworming, iron-folic acid, nutrients supplementation, (boost-)immunization) and as a possible delivery system for IPT in schoolchildren (IPTsc). However, the current evidence on the efficacy and safety of IPTsc is limited and the optimal therapeutic regimen remains controversial. METHODS: A systematic search for studies reporting efficacy and safety of IPT in schoolchildren was conducted using PubMed, Web of Science, Clinicaltrials and WHO/ICTRP database, and abstracts from congresses with the following key words: intermittent, preventive treatment AND malaria OR Plasmodium falciparum AND schoolchildren NOT infant NOT pregnancy. RESULTS: Five studies were identified. Most IPTsc regimes demonstrated substantial protection against malaria parasitaemia, with dihydroartemisinin-piperaquine (DP) given monthly having the highest protective effect (PE) (94 %; 95 % CI 93-96). Contrarily, SP did not provide any PE against parasitaemia. However, no IPT regimen provided a PE above 50 % in regard to anaemia, and highest protection was provided by SP+ amodiaquine (AQ) given four-monthly (50 %; 95 % CI 41-53). The best protection against clinical malaria was observed in children monthly treated with DP (97 %; 95 % CI 87-98). However, there was no protection when the drug was given three-monthly. No severe adverse events were associated with the drugs used for IPTsc. CONCLUSION: IPTsc may reduce the malaria-related burden in schoolchildren. However, more studies assessing efficacy of IPT in particular against malaria-related anaemia and clinical malaria in schoolchildren must be conducted.

Malaria policies versus practices, a reality check from Kinshasa, the capital of the Democratic Republic of Congo.

BACKGROUND: Artemisinin-based combination therapy (ACT) following a confirmed parasitological diagnosis is recommended by the World Health Organization (WHO) and the Congolese National Malaria Control Program (NMCP). However, commitment and competence of all stakeholders (patients, medical professionals, governments and funders) is required to achieve effective case management and secure the "useful therapeutic life" of the recommended drugs. The health seeking behaviour of patients and health care professionals' practices for malaria management were assessed. METHODS: This was an observational study embedded in a two-stage cluster randomized survey conducted in one health centre (HC) in each of the 12 selected health zones in Kinshasa city. All patients with clinical malaria diagnosis were eligible. Their health seeking behaviour was recorded on a specific questionnaire, as well as the health care practitioners' practices. The last were not aware that their practices would be assessed. RESULTS: Six hundred and twenty four patients were assessed, of whom 136 (21.8%) were under five years. Three hundred and thirty five (55%) had taken medication prior to the current consultation (self -medication with any product or visiting another HC) of whom 47(14%) took an antimalarial drug, and 56 (9%) were treated presumptively. Among those, 53.6% received monotherapy either with quinine, artesunate, phytomedicines, sulfadoxine-pyrimethamine or amodiaquine. On the other side, when clinicians were informed about laboratory results, monotherapy was prescribed in 39.9% of the confirmed malaria cases. Only 285 patients (45.7%) were managed in line with WHO and NMCP guidelines, of whom 120 (19.2%) were prescribed an ACT after positive blood smear and 165 (26.4%) received no antimalarial after a negative result. CONCLUSION: This study shows the discrepancy between malaria policies and the reality on the field in Kinshasa, regarding patients' health seeking behaviour and health professionals' practices. Consequently, the poor compliance to the policies may contribute to the genesis and spread of antimalarial drug resistance and also have a negative impact on the burden of the disease.

High prevalence of Schistosoma mansoni in six health areas of - Kasansa health zone, Democratic Republic of the Congo: short report.

School-aged children suffer the most from schistosomiasis infection in sub Saharan Africa due to poverty and limited sanitary conditions. Mapping of disease burden is recommended and there is a need of updating prevalence data which is as old as 20 years in the Democratic Republic of Congo. An epidemiological and parasitological study was carried out in 2011 in the health zone of Kasansa. Six health areas (HA) were included in the study. In each health area, one primary school was selected. School-aged children were screened for S. mansoni infection using parallel Kato-Katz and direct microscopy techniques. A total of 335 school-aged children were screened. The average prevalence was 82.7% and ranged between 59.5-94.9%. Four of the six HAs had a prevalence level over 91%. Of all infected children, about half 112 (43.2%) had light parasite density. These results demonstrate that Schistosoma mansoni infection is a bigger problem than anticipated and there is an urgent need to implement effective control measures.

Malaria, schistosomiasis and soil transmitted helminth burden and their correlation with anemia in children attending primary schools in Kinshasa, Democratic Republic of Congo.

BACKGROUND: Anaemia reduces cognitive potential in school children, retards their growth and predisposes them to other diseases. As there is a paucity of data on the current burden of P. falciparum, S. mansoni and soil transmitted helminths (STH) infections and their correlation with schoolchildren's anemia in the Democratic Republic of Congo (DRC), we collect these data. METHODS: This study reports baseline data collected from a randomized controlled trial investigating the impact of IPT with SP and SP-PQ on anemia and malaria morbidity in Congolese schoolchildren (Trial registration: NCT01722539; PACTR201211000449323). S. mansoni and STH infections were assessed using kato-katz technique. Malaria infection and hemoglobin concentration were assessed using Blood smear and Hemocontrol device, respectively. RESULTS: A total of 616 primary schoolchildren from 4 to 13 years old were enrolled in the study. The prevalence of Plasmodium spp. infection was 18.5% (95%CI:15.6-21.9). Amongst those infected, 24 (21%), 40 (35.1%), 40 (35.1%), 10 (8.8%), had light, moderate, heavy, very high malaria parasite density, respectively. Above 9 years of age (p = 0.02), male and history of fever (p = 0.04) were both associated with malaria infection. The overall prevalence of S. mansoni infection was 6.4% (95%CI:4.4-9.1). Girls were associated with S. mansoni infection (p = 0.04). T. trichiura was the most prevalent STH infection (26.3%), followed by A. lumbricoides (20.1%). Co-infection with malaria-S. mansoni and malaria-STH was, respectively, 1.5% (CI95%:0.7-3.3) and 6.4% (CI95% 4.4-9.1). The prevalence of anemia was found to be 41.6% (95%CI:37.7-45.6) and anemia was strongly related with Plasmodium ssp infection (aOR:4.1; CI95%:2.6-6.5;p<0.001) and S. mansoni infection (aOR:3.3;CI95%:1.4-7.8;p<0.01). CONCLUSION: Malaria and S. mansoni infection were strongly associated with high prevalence of anemia in schoolchildren. Therefore, specific school-based interventions, such as intermittent preventive treatment or prophylaxis, LLITN distribution, anthelminthic mass treatment and micronutrient supplementation are needed to improve school children's health.

Asymptomatic Plasmodium falciparum infection is associated with anaemia in pregnancy and can be more cost-effectively detected by rapid diagnostic test than by microscopy in Kinshasa, Democratic Republic of the Congo.

BACKGROUND: In areas of high malaria transmission, Plasmodium falciparum infection during pregnancy is characterized by malaria-related anaemia, placental malaria and does not always result in clinical symptoms. This situation is associated with poor pregnancy outcomes. The aim of this study was to determine the extent of asymptomatic P. falciparum infection, its relation with anaemia as well as the most cost-effective technique for its diagnosis in healthy pregnant women living in Kinshasa, Democratic Republic of the Congo. METHODS: In a cross-sectional study design, information on socio-demographic characteristics and cost data were collected in healthy pregnant women attending antenatal care consultations. Plasmodium falciparum infection was diagnosed using rapid diagnostic test (RDT), microscopy and polymerase chain reaction (PCR). Haemoglobin concentration was also determined. RESULTS: In total, 332 pregnant women were enrolled. RDT and microscopy data were available for all the blood samples and 166 samples were analysed by PCR. The prevalence of asymptomatic P. falciparum infection using microscopy, RDTs and PCR, were respectively 21.6%, 27.4% and 29.5%. Taking PCR as a reference, RDTs had a sensitivity of 81.6% and a specificity of 94.9% to diagnose asymptomatic P. falciparum infection. The corresponding values for microscopy were 67.3% and 97.4%. The prevalence of anaemia was 61.1% and asymptomatic malaria increased five times the odds (p < 0.001) of having anaemia. RDTs were more cost-effective compared to microscopy. Incremental cost-effectiveness ratio was US$ 63.47 per microscopy adequately diagnosed case. CONCLUSION: These alarming results emphasize the need to actively diagnose and treat asymptomatic malaria infection during all antenatal care visits. Moreover, in DRC, malaria and anaemia control efforts should be strengthened by promoting the use of insecticide-treated nets, intermittent preventive treatment with sulphadoxine-pyrimethamine and iron and folic acid supplements.

Toxoplasmosis among pregnant women: high seroprevalence and risk factors in Kinshasa, Democratic Republic of Congo.

OBJECTIVE: To determine the seroprevalence of toxoplasmosis in pregnant women, as well as the proportion of acutely infected and risk factors in the Democratic Republic of Congo. METHODS: Thirty maternities in Kinshasa were randomly selected and women attending antenatal consultation were invited to participate. They were interviewed with a structured questionnaire about known risk factors (age, meat consumption, contact with soil, and presence of cat) and a venous blood sample was taken. Sera were analysed for total immunoglobulins (Ig) by VIDAS Toxo Competition using Enzyme Linked Fluorescent Assay. IgM was determined by VIDIA Toxo IgM and IgG avidity by VIDAS Toxo IgG avidity. RESULTS: A total of 781 women were included. Median age was 28 years old (IQR: 8.5). And 627 women (80.3%; 95% CI: 77.5-83.1) were found to be positive to total Ig and 17 out of 387 (4.4%; 95% CI: 2.3-6.4) were positive to IgM. IgG avidity was low for 2 (11.8%) women, intermediate for 2 (11.8%) and high for 13 women (76.4%). There was no statistically significant association between Toxoplasma gondii infection and any risk factors assessed. CONCLUSION: In Kinshasa, toxoplasmosis endemicity is highly prevalent. One woman out of twenty five had a recent toxoplasmosis infection and 20% were not protected against primo-infection, indicating a need for measures to prevent and control toxoplasmosis during pregnancy.

Toxoplasmosis among pregnant women: high seroprevalence and risk factors in Kinshasa, Democratic Republic of Congo

<p><b>OBJECTIVE</b>To determine the seroprevalence of toxoplasmosis in pregnant women, as well as the proportion of acutely infected and risk factors in the Democratic Republic of Congo.</p><p><b>METHODS</b>Thirty maternities in Kinshasa were randomly selected and women attending antenatal consultation were invited to participate. They were interviewed with a structured questionnaire about known risk factors (age, meat consumption, contact with soil, and presence of cat) and a venous blood sample was taken. Sera were analysed for total immunoglobulins (Ig) by VIDAS Toxo Competition using Enzyme Linked Fluorescent Assay. IgM was determined by VIDIA Toxo IgM and IgG avidity by VIDAS Toxo IgG avidity.</p><p><b>RESULTS</b>A total of 781 women were included. Median age was 28 years old (IQR: 8.5). And 627 women (80.3%; 95% CI: 77.5-83.1) were found to be positive to total Ig and 17 out of 387 (4.4%; 95% CI: 2.3-6.4) were positive to IgM. IgG avidity was low for 2 (11.8%) women, intermediate for 2 (11.8%) and high for 13 women (76.4%). There was no statistically significant association between Toxoplasma gondii infection and any risk factors assessed.</p><p><b>CONCLUSION</b>In Kinshasa, toxoplasmosis endemicity is highly prevalent. One woman out of twenty five had a recent toxoplasmosis infection and 20% were not protected against primo-infection, indicating a need for measures to prevent and control toxoplasmosis during pregnancy.</p>

Perceptions of health, health care and community-oriented health interventions in poor urban communities of Kinshasa, Democratic Republic of Congo.

In Democratic Republic of Congo access to health care is limited because of many geographical and financial barriers, while quality of care is often low. Global health donors assist the country with a number of community-oriented interventions such as free distribution of bednets, antihelminthic drugs, vitamin A supplementation and vaccination campaigns, but uptake of these interventions is not always optimal. The aim of this study was to explore the perceptions of poor urban communities of the capital Kinshasa with regard to health issues in general as well as their experiences and expectations concerning facility-based health services and community-oriented health interventions. Applying an approach rooted in the grounded theory framework, focus group discussions were conducted in eight neighborhoods of poor urban areas in the city of Kinshasa in July 2011. Study participants were easily able to evoke the city's major health problems, with the notable exceptions of malnutrition and HIV/AIDS. They perceive the high out-of-pocket cost of health services as the major obstacle when seeking access to quality care. Knowledge of ongoing community-oriented health interventions seems good. Still, while the study participants agree that those interventions are beneficial; their acceptability seems to be problematic. This is chiefly put down to a lack of information and government communication about the programs and their interventions. Furthermore, the study participants referred to rumors and the deterring effect of stories about alleged harmful consequences of those interventions. Along with improving the provision and quality of general health care, the government and international actors must improve their efforts in informing the communities about disease control programs, their rationale and benefit/risk ratio. Directly engaging community members in a dialogue might be beneficial in terms of improving acceptability and overall access to health services and interventions. Novel ways of reducing the high out-of-pocket expenditure should also be explored.

Experimental induction of paromomycin resistance in antimony-resistant strains of L. donovani: outcome dependent on in vitro selection protocol.

Paromomycin (PMM) has recently been introduced for treatment of visceral leishmaniasis in India. Although no clinical resistance has yet been reported, proactive vigilance should be warranted. The present in vitro study compared the outcome and stability of experimental PMM-resistance induction on promastigotes and intracellular amastigotes. Cloned antimony-resistant L. donovani field isolates from India and Nepal were exposed to stepwise increasing concentrations of PMM (up to 500 µM), either as promastigotes or intracellular amastigotes. One resulting resistant strain was cloned and checked for stability of resistance by drug-free in vitro passage as promastigotes for 20 weeks or a single in vivo passage in the golden hamster. Resistance selection in promastigotes took about 25 weeks to reach the maximal 97 µM inclusion level that did not affect normal growth. Comparison of the IC(50) values between the parent and the selected strains revealed a 9 to 11-fold resistance for the Indian and 3 to 5-fold for the Nepalese strains whereby the resistant phenotype was also maintained at the level of the amastigote. Applying PMM pressure to intracellular amastigotes produced resistance after just two selection cycles (IC(50) = 199 µM) compared to the parent strain (IC(50) = 45 µM). In the amastigote-induced strains/clones, lower PMM susceptibilities were seen only in amastigotes and not at all in promastigotes. This resistance phenotype remained stable after serial in vitro passage as promastigote for 20 weeks and after a single in vivo passage in the hamster. This study clearly demonstrates that a different PMM-resistance phenotype is obtained whether drug selection is applied to promastigotes or intracellular amastigotes. These findings may have important relevance to resistance mechanism investigations and the likelihood of resistance development and detection in the field.

In vitro and in vivo prophylactic and curative activity of the triterpene saponin PX-6518 against cutaneous Leishmania species.

OBJECTIVES: The oleanane triterpene saponin PX-6518, with known potent in vitro and in vivo activity against Leishmania donovani, was investigated for its spectrum against the cutaneous species Leishmania mexicana, Leishmania panamensis and Leishmania major. METHODS: In vitro activity was based on the reduction of amastigotes in primary peritoneal mouse macrophages. BALB/c mice were injected with 2 × 10(6) amastigotes in the base of the tail (L. panamensis and L. major) or the foot (L. mexicana) and subcutaneously treated with PX-6518 [1-10 mg/kg body weight (BW)] or Pentostam(®) (250 mg/kg BW Sb(V) eq). Evolution of skin lesions was monitored in a prophylactic dose-finding study, and early curative [6 weeks post-infection (pi)] and late curative (>8-10 weeks pi) studies. RESULTS: While moderate susceptibility to PX-6518 was obtained in vitro (IC(50): 1-4 µg/mL), excellent in vivo activity was demonstrated. In the prophylactic study (six administrations on alternate days, starting at 1 day pi), PX-6518 was 100% effective at 1 mg/kg BW against L. mexicana and L. panamensis, whereas L. major lesions could be prevented at 2 mg/kg BW. In the early curative (1 mg/kg BW once a week for 4 weeks) and late curative (1 mg/kg BW twice a week for 4 weeks) studies, PX-6518 completely healed L. mexicana and L. panamensis lesions, whereas L. major lesions were reduced by ∼ 50%. CONCLUSIONS: This study demonstrates that PX-6518 possesses potent and broad-spectrum prophylactic and curative efficacy against cutaneous leishmaniasis in the BALB/c mouse model. L. major was the least susceptible species tested and parasitological cure could not be obtained.