RESUMO
BACKGROUND: Globally, a fifth of the children continue to face chronic undernutrition with a majority of them situated in the Low- and Middle-Income Countries (LMIC). The rising numbers are attributed to aggravating factors like limited nutrition knowledge, poor feeding practices, seasonal food insecurity, and diseases. Interventions targeting behaviour change may reduce the devastating nutrition situation of children in the LMICs. OBJECTIVE: For the co-design of a Behaviour Change Communication (BCC) intervention for young children in rural Kenya, we aimed to identify the experiences, barriers, facilitators, and preferences of caregivers and stakeholders regarding nutrition and health counselling. DESIGN: We employed a qualitative study design and used a semi-structured interview guide. The in-depth interviews were recorded, transcribed, and analysed using content analysis, facilitated by the software NVivo. SETTING: Health and Demographic Surveillance System (HDSS) area in Siaya County, rural Kenya. PARTICIPANTS: We interviewed 30 caregivers of children between 6 and 23 months of age and 29 local stakeholders with experience in implementing nutrition projects in Kenya. RESULTS: Nutrition and health counselling (NHC) was usually conducted in hospital settings with groups of mothers. Barriers to counselling were long queues and delays, long distances and high travel costs, the inapplicability of the counselling content, lack of spousal support, and a high domestic workload. Facilitators included the trust of caregivers in Community Health Volunteers (CHVs) and counselling services offered free of charge. Preferences comprised (1) delivering of counselling by CHVs, (2) offering individual and group counselling, (3) targeting male and female caregivers. CONCLUSION: There is a disconnect between the caregivers' preferences and the services currently offered. Among these families, a successful BCC strategy that employs nutrition and health counselling should apply a community-based communication channel through trusted CHVs, addressing male and female caregivers, and comprising group and individual sessions.
Assuntos
Cuidadores , Aconselhamento , Pesquisa Qualitativa , População Rural , Humanos , Quênia , Cuidadores/psicologia , Aconselhamento/métodos , Lactente , Feminino , Masculino , Adulto , Entrevistas como AssuntoRESUMO
BACKGROUND: It has been proposed that childhood vaccines in high-mortality populations may have substantial impacts on mortality rates that are not explained by the prevention of targeted diseases, nor conversely by typical expected adverse reactions to the vaccines, and that these non-specific effects (NSEs) are generally more pronounced in females. The existence of these effects, and any implications for the development of vaccines and the design of vaccination programs to enhance safety, remain controversial. One area of controversy is the reported association of non-live vaccines with increased female mortality. In a previous randomized controlled trial (RCT), we observed that non-live alum-adjuvanted animal rabies vaccine (ARV) was associated with increased female but not male mortality in young, free-roaming dogs. Conversely, non-live non-adjuvanted human rabies vaccine (NRV) has been associated with beneficial non-specific effects in children. Alum adjuvant has been shown to suppress Th1 responses to pathogens, leading us to hypothesize that alum-adjuvanted rabies vaccine in young dogs has a detrimental effect on female survival by modulating the immune response to infectious and/or parasitic diseases. In this paper, we present the protocol of a 3-arm RCT comparing the effect of alum-adjuvanted rabies vaccine, non-adjuvanted rabies vaccine and placebo on all-cause mortality in an owned, free-roaming dog population, with causal mediation analysis of the RCT and a nested case-control study to test this hypothesis. METHODS: Randomised controlled trial with a nested case-control study. DISCUSSION: We expect that, among the placebo group, males will have higher mortality caused by higher pathogen loads and more severe disease, as determined by haematological parameters and inflammatory biomarkers. Among females, we expect that there will be no difference in mortality between the NRV and placebo groups, but that the ARV group will have higher mortality, again mediated by higher pathogen loads and more severe disease. We anticipate that these changes are preceded by shifts in key serum cytokine concentrations towards an anti-inflammatory immune response in females. If confirmed, these results will provide a rational basis for mitigation of detrimental NSEs of non-live vaccines in high-mortality populations.
Assuntos
Doenças do Cão , Vacina Antirrábica , Raiva , Adjuvantes Imunológicos/farmacologia , Compostos de Alúmen , Animais , Anti-Inflamatórios , Biomarcadores , Estudos de Casos e Controles , Ensaios Clínicos Veterinários como Assunto , Citocinas , Doenças do Cão/epidemiologia , Doenças do Cão/prevenção & controle , Cães , Feminino , Humanos , Masculino , Raiva/epidemiologia , Raiva/prevenção & controle , Raiva/veterinária , Vacinação/veterináriaRESUMO
Unlike praziquantel, artemisinin derivatives are effective against juvenile schistosome worms. We assessed the efficacy and safety of a single oral dose of artesunate plus sulfalene-pyrimethamine versus praziquantel in the treatment of Schistosoma mansoni. Seventy-three schoolchildren (aged 9-15 years) with confirmed S. mansoni infection in Rarieda, western Kenya, were randomly assigned to receive either a single oral dose of artesunate plus sulfalene-pyrimethamine (n = 39) or a single dose of praziquantel (n = 34). The cure and egg reduction rates at 4 weeks posttreatment were 69.4% (25/36) versus 80.6% (25/31) (P = 0.297) and 99.1% versus 97.5% (P = 0.607) in the artesunate plus sulfalene-pyrimethamine group versus praziquantel group, respectively. Fourteen children developed adverse events, and there were no serious adverse events. A single oral dose of artesunate plus sulfalene-pyrimethamine has efficacy comparable to that of praziquantel in the treatment of S. mansoni, but these results should be confirmed in larger randomized controlled trials.
Assuntos
Anti-Helmínticos , Artemisininas , Esquistossomose mansoni , Sulfaleno , Adolescente , Animais , Criança , Humanos , Anti-Helmínticos/uso terapêutico , Artemisininas/efeitos adversos , Artesunato/uso terapêutico , Quimioterapia Combinada , População da África Oriental , Quênia , Praziquantel/efeitos adversos , Pirimetamina/uso terapêutico , Schistosoma mansoni , Esquistossomose mansoni/tratamento farmacológico , Sulfaleno/farmacologia , Sulfaleno/uso terapêutico , Resultado do TratamentoRESUMO
BACKGROUND: Reliance on praziquantel for the treatment and control of schistosomiasis is likely to facilitate the emergence of drug resistance. Combination therapy targeting adult and juvenile schistosome worms is urgently needed to improve praziquantel efficacy and delay the potential development of drug resistance. We assessed the efficacy and safety of single-dose praziquantel combined with single-dose artesunate plus sulfalene-pyrimethamine in the treatment of Kenyan children with schistosomiasis. METHODS: This was an open-label, randomised clinical trial involving 426 school-aged children (7-15 years old) diagnosed with Schistosoma mansoni (by Kato-Katz) or S. haematobium (by urine filtration). They were randomly assigned (1:1:1) to receive a single dose of praziquantel (40 mg/kg), a single dose of artesunate plus sulfalene-pyrimethamine (12 mg/kg artesunate) or combination therapy using a single dose of praziquantel (40 mg/kg) combined with a single dose of artesunate plus sulfalene-pyrimethamine (12 mg/kg artesunate). The primary outcome was cure and egg reduction rates at 6 weeks post-treatment in the available case population. Adverse events were assessed within 3 h after treatment. RESULTS: Of the 426 children enrolled, 135 received praziquantel, 150 received artesunate plus sulfalene-pyrimethamine, and 141 received combination therapy. Outcome data were available for 348 (81.7%) children. For S. mansoni-infected children (n = 335), the cure rates were 75.6%, 60.7%, and 77.8%, and the egg reduction rates were 80.1%, 85.0%, and 88.4% for praziquantel, artesunate plus sulfalene-pyrimethamine, and combination therapy, respectively. For S. haematobium-infected children (n = 145), the corresponding cure rates were 81.4%, 71.1%, and 82.2%, and the egg reduction rates were 95.6%, 97.1%, and 97.7%, respectively. Seventy-one (16.7%) children reported mild-intensity adverse events. The drugs were well tolerated and no serious adverse events were reported. CONCLUSIONS: A single oral dose of praziquantel combined with artesunate plus sulfalene-pyrimethamine cured a high proportion of children with S. haematobium but did not significantly improve the treatment efficacy for either urinary or intestinal schistosomiasis. Sequential administration of praziquantel and artesunate plus sulfalene-pyrimethamine may enhance the efficacy and safety outcomes.
Assuntos
Anti-Helmínticos , Artemisininas , Artesunato , Quimioterapia Combinada , Praziquantel , Pirimetamina , Schistosoma haematobium , Schistosoma mansoni , Esquistossomose Urinária , Esquistossomose mansoni , Humanos , Criança , Praziquantel/administração & dosagem , Praziquantel/efeitos adversos , Praziquantel/uso terapêutico , Pirimetamina/administração & dosagem , Pirimetamina/uso terapêutico , Pirimetamina/efeitos adversos , Animais , Adolescente , Artesunato/administração & dosagem , Artesunato/uso terapêutico , Feminino , Masculino , Esquistossomose mansoni/tratamento farmacológico , Schistosoma haematobium/efeitos dos fármacos , Esquistossomose Urinária/tratamento farmacológico , Schistosoma mansoni/efeitos dos fármacos , Quênia , Artemisininas/administração & dosagem , Artemisininas/uso terapêutico , Artemisininas/efeitos adversos , Resultado do Tratamento , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/efeitos adversos , Anti-Helmínticos/uso terapêutico , Sulfaleno/administração & dosagem , Sulfaleno/uso terapêutico , Sulfaleno/efeitos adversos , Combinação de Medicamentos , Contagem de Ovos de ParasitasRESUMO
BACKGROUND: Schistosomiasis control relies on praziquantel for preventive chemotherapy. Alternative drugs are needed for the treatment and control of schistosomiasis. Praziquantel is effective against adult schistosome worms but ineffective against larval stages of the parasite and cannot prevent re-infection or interrupt the transmission of infection. Continued reliance on praziquantel for wide-scale schistosomiasis control will likely accelerate the emergence of drug resistance. Artemisinin derivatives are effective against the juvenile stages but ineffective against adult worms. The SCHISTOACT study aimed to evaluate the efficacy and safety of praziquantel plus one of four artemisinin-based combinations in treating Schistosoma mansoni infection in Kenya. METHODS: The SCHISTOACT study is an open-label, head-to-head, five-arm, proof-of-concept, non-inferiority, individually randomized controlled trial with a follow-up of 12 weeks. A total of 540 primary school-aged children from the Mwea area, Kirinyaga County in central Kenya, diagnosed with S. mansoni infection (by Kato-Katz method) are randomly allocated (1:1:1:1:1) to a single dose of praziquantel plus a 3-day course of artesunate-sulfalene/pyrimethamine, or artesunate-amodiaquine, or artesunate plus mefloquine, or dihydroartemisinin-piperaquine, or praziquantel control arm. The primary endpoints are efficacy (cure rate, assessed by microscopy) and safety (adverse events) of each study arm 6 weeks after treatment. Secondary endpoints include cumulative cure rate, egg reduction rate, and re-infection 12 weeks after treatment. The non-inferiority margin is set at - 10 for the risk difference in cure rates between praziquantel and the combined treatment. DISCUSSION: This study assesses a strategy for repurposing artemisinin-based combination therapies (ACTs) for treating schistosomiasis. It adopts a head-to-head comparison of four different ACTs to test a non-inferiority hypothesis and to strengthen local capacity to conduct clinical trials for interventions against neglected tropical diseases. TRIAL REGISTRATION: Pan-African Clinical Trials Registry PACTR202001919442161 . Retrospectively registered on 6 January 2020.
Assuntos
Anti-Helmínticos , Artemisininas , Esquistossomose mansoni , Esquistossomose , Adulto , Animais , Criança , Humanos , Artemisininas/efeitos adversos , Artesunato/efeitos adversos , Quimioterapia Combinada , Praziquantel/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Reinfecção/induzido quimicamente , Reinfecção/tratamento farmacológico , Schistosoma mansoni , Esquistossomose/tratamento farmacológico , Esquistossomose mansoni/diagnóstico , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/induzido quimicamente , Resultado do Tratamento , Estudos de Equivalência como AsuntoRESUMO
BACKGROUND: Climate change heavily affects child nutritional status in sub-Saharan Africa. Agricultural and dietary diversification are promising tools to balance agricultural yield losses and nutrient deficits in crops. However, rigorous impact evaluation of such adaptation strategies is lacking. This project will determine the potential of an integrated home gardening and nutrition counseling program as one possible climate change adaptation strategy to improve child health in rural Burkina Faso and Kenya. METHODS: Based on careful co-design with stakeholders and beneficiaries, we conduct a multi-center, cluster-randomized controlled trial with 2 × 600 households in North-Western Burkina Faso and in South-Eastern Kenya. We recruit households with children at the age of complementary feed introduction (6-24 months) and with access to water sources. The intervention comprises the bio-diversification of horticultural home gardens and nutritional health counseling, using the 7 Essential Nutrition Action messages by the World Health Organization. After 12-months of follow-up, we will determine the intervention effect on the primary health outcome height-for-age z-score, using multi-level mixed models in an intention-to-treat approach. Secondary outcomes comprise other anthropometric indices, iron and zinc status, dietary behavior, malaria indicators, and household socioeconomic status. DISCUSSION: This project will establish the potential of a home gardening and nutrition counseling program to counteract climate change-related quantitative and qualitative agricultural losses, thereby improving the nutritional status among young children in rural sub-Saharan Africa. TRIAL REGISTRATION: German Clinical Trials Register (DRKS) DRKS00019076 . Registered on 27 July 2021.
Assuntos
Transtornos da Nutrição Infantil , Desnutrição , Burkina Faso , Criança , Transtornos da Nutrição Infantil/diagnóstico , Transtornos da Nutrição Infantil/prevenção & controle , Pré-Escolar , Aconselhamento , Jardinagem , Jardins , Humanos , Lactente , Quênia , Desnutrição/diagnóstico , Desnutrição/prevenção & controle , Estudos Multicêntricos como Assunto , Estado Nutricional , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
BACKGROUND: Age prevalence curves for areas in which schistosomiasis is endemic suggest that humans develop partial immunity to reinfection beginning in early adolescence. We conducted a 2-year longitudinal study to determine whether children infected with Schistosoma mansoni develop protection-related immune responses after treatment with praziquantel and whether the development of these immune responses is accelerated by frequent treatment after reinfection. METHODS: Children (8-10 years old) were tested for S. mansoni every 4 months and treated with praziquantel when positive (arm A; n=68) or were tested and treated at the end of the 2-year follow-up period (arm B; n=49). RESULTS: Children in arm A who remained free of infection during follow-up had significantly higher baseline levels of schistosome-specific immunoglobulin E (IgE) than did children with > or =2 repeat diagnoses of S. mansoni infection. Children with > or =2 repeat diagnoses of S. mansoni infection had significantly increased levels of anti-schistosome IgE and CD23(+) B cells after receiving > or =3 praziquantel treatments over the course of follow-up. No increase in either parameter was seen in children who received only the baseline praziquantel treatment. CONCLUSIONS: B cell activation and anti-schistosome IgE are associated with resistance to S. mansoni in children, and these immunological parameters can be increased by multiple rounds of infections and praziquantel-induced cures.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Linfócitos B/imunologia , Imunoglobulina E/sangue , Receptores de IgE/análise , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Animais , Anti-Helmínticos/uso terapêutico , Linfócitos B/química , Criança , Feminino , Humanos , Quênia , Estudos Longitudinais , Masculino , Praziquantel/uso terapêutico , Recidiva , Esquistossomose mansoni/tratamento farmacológicoRESUMO
BACKGROUND: Among the different faces of immune reconstitution inflammatory syndrome (IRIS) developing in HIV-patients, no clinical definition has been reported for Schistosomiasis-IRIS (Schisto-IRIS). Although Schisto-IRIS remains largely uninvestigated, matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) have previously been associated with S. mansoni infection and tuberculosis-IRIS. Here, we aimed to investigate the relevance of these markers in Schisto-IRIS. METHODOLOGY: Patients were diagnosed with IRIS related to S. mansoni within a cohort of patients with Schistosomiasis-HIV co-infection, using a clinical working definition of Schisto-IRIS. We compared 9 patients who developed Schisto-IRIS to 9 Schisto+HIV+ controls who did not, and 9 Schisto-HIV+ controls. Plasma levels of MMP-1, MMP-7, MMP-10, TIMP-1, TIMP-2, sCD14, intestinal fatty-acid binding protein, C-reactive protein, and 8 anti-nuclear antibodies (ANA) were analyzed prior to and during 3 months of ART. PRINCIPAL FINDINGS: Although no differences were observed for MMP-1 and -7, MMP-10 levels decreased significantly in Schisto+HIV+ controls during 3 months of ART (p = 0.005) while persisting in Schisto-IRIS patients at significantly higher levels compared to Schisto-HIV+ controls (p≤0.030). In contrast TIMP-1 levels only decreased significantly in Schisto-IRIS patients (p = 0.012), while TIMP-2 levels were lower compared to Schisto+HIV+ controls at 2 weeks (p = 0.007), 1 month (p = 0.005) and 3 months (p = 0.031) of ART. Five out of 8 ANAs studied decreased significantly in Schisto-IRIS patients after 1 month of ART(p≤0.039), whereas only 1 ANA decreased for Schisto+HIV+ controls (p = 0.027). CONCLUSIONS/SIGNIFICANCE: In this study, we propose a working definition for the diagnosis of Schisto-IRIS in resource limited settings. We report persistent plasma levels of MMP-10, along with a more pronounced decrease in TIMP-1 and ANA-levels, and low levels of TIMP-2 during 3 months of ART. Corresponding to the clinical symptoms, these data suggest that Schisto-IRIS is marked by unbalanced MMP/TIMP dynamics which favor inflammation.
Assuntos
Síndrome Inflamatória da Reconstituição Imune/diagnóstico , Síndrome Inflamatória da Reconstituição Imune/etiologia , Metaloproteinases da Matriz/metabolismo , Esquistossomose mansoni/complicações , Inibidores Teciduais de Metaloproteinases/metabolismo , Adulto , Animais , Biomarcadores , Estudos de Casos e Controles , Estudos de Coortes , Coinfecção , Feminino , Infecções por HIV , Humanos , Quênia/epidemiologia , Masculino , Metaloproteinases da Matriz/sangue , Schistosoma mansoni , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/imunologia , Inibidores Teciduais de Metaloproteinases/sangueRESUMO
The potential consequences of parasitic infections on a person's immune responsiveness to unrelated antigens are often conjectured upon in relationship to allergic responses and autoimmune diseases. These considerations sometimes extend to whether parasitic infection of pregnant women can influence the outcomes of responses by their offspring to the immunizations administered during national Expanded Programs of Immunization. To provide additional data to these discussions, we have enrolled 99 close-to-term pregnant women in western Kenya and determined their Schistosoma mansoni and Plasmodium falciparum infection status. At 2 years of age, when the initial immunization schedule was complete, we determined their children's IgG antibody levels to tetanus toxoid, diphtheria toxoid, and measles nucleoprotein (N-protein) antigens using a multiplex assay. We also monitored antibody responses during the children's first 2 years of life to P. falciparum MSP119 (PfMSP119), S. mansoni Soluble Egg Antigen (SEA), Ascaris suum hemoglobin (AsHb), and Strongyloides stercoralis (SsNIE). Mothers' infections with either P. falciparum or S. mansoni had no impact on the level of antibody responses of their offspring or the proportion of offspring that developed protective levels of antibodies to either tetanus or diphtheria antigens at 2 years of age. However, children born of S. mansoni-positive mothers and immunized for measles at 9 months of age had significantly lower levels of anti-measles N-protein antibodies when they were 2 years old (p = 0.007) and a lower proportion of these children (62.5 vs. 90.2%, OR = 0.18, 95% CI = 0.04-0.68, p = 0.011) were considered positive for measles N-protein antibodies. Decreased levels of measles antibodies may render these children more susceptible to measles infection than children whose mothers did not have schistosomiasis. None of the children demonstrated responses to AsHb or SsNIE during the study period. Anti-SEA and anti-PfMSP119 responses suggested that 6 and 70% of the children acquired schistosomes and falciparum malaria, respectively, during the first 2 years of life.
RESUMO
Schistosomiasis mansoni is usually a chronic infection that leads to long-term, systemic exposure to schistosome antigens. Experimental Schistosoma mansoni infection is associated with immunoregulatory mechanisms, including T regulatory cells (Treg) that may help control morbidity and dampen resistance to re-infection. We now show that some schistosomiasis mansoni patients have high proportions of CD3(+)/CD4(+)/CD25(high) Treg. On effective treatment with praziquantel, these high Treg percentages decrease, and fewer of the remaining Treg express CD45RO. The proportion of Treg in S. mansoni-infected patients is inversely related to their percentage of activated, putative effector T cells (CD3(+)/CD4(+)/CD25(medium)/HLA-DR(+) cells). We conclude some, but not all, schistosomiasis mansoni patients develop high percentages of circulating Treg, and effective treatment both decreases the levels of these cells and changes their phenotypes, possibly because of the removal of constant exposure to antigens from intravascular, egg-producing adult worms.
Assuntos
Praziquantel/uso terapêutico , Schistosoma mansoni/imunologia , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/imunologia , Linfócitos T Reguladores/imunologia , Adolescente , Adulto , Animais , Anti-Helmínticos/uso terapêutico , Linfócitos T CD4-Positivos/imunologia , Eosinofilia/imunologia , Soropositividade para HIV/imunologia , HIV-1/imunologia , Humanos , Subunidade alfa de Receptor de Interleucina-2/imunologia , Antígenos Comuns de Leucócito/biossíntese , Antígenos Comuns de Leucócito/imunologia , Masculino , Pessoa de Meia-Idade , Linfócitos T Reguladores/patologiaRESUMO
Previously, we have shown that persons with human immunodeficiency virus 1 (HIV-1) infection and reduced CD4(+) T-lymphocyte counts excrete significantly fewer Schistosoma mansoni eggs than HIV-1-negative persons with similar intensities of schistosome infections. To determine how antiretroviral therapy (ART) might affect egg excretion, we conducted a study of HIV+ adults living in an area highly endemic for S. mansoni as they began an ART program. Fecal egg excretion and CD4(+) T-lymphocyte counts were evaluated at enrollment as well as 2 and 4 weeks after initiation of ART. Fourteen individuals who were Kato-Katz-negative at enrollment subsequently started excreting S. mansoni eggs accompanied by a significant increase in CD4(+) T lymphocytes (P = 0.004). Study participants who were S. mansoni egg-positive at enrollment and received both praziquantel and ART also showed significantly increased CD4(+) T-lymphocyte counts compared with baseline (P < 0.0001). Our data support a role for CD4(+) T lymphocytes in S. mansoni egg excretion.
Assuntos
Fármacos Anti-HIV/uso terapêutico , Contagem de Linfócito CD4 , Fezes/parasitologia , Infecções por HIV/complicações , Contagem de Ovos de Parasitas , Esquistossomose mansoni/complicações , Adulto , Animais , Anti-Helmínticos/uso terapêutico , Coinfecção/tratamento farmacológico , Coinfecção/parasitologia , Coinfecção/virologia , Fezes/virologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/parasitologia , HIV-1 , Humanos , Praziquantel/uso terapêutico , Schistosoma mansoni , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/parasitologia , Esquistossomose mansoni/virologiaRESUMO
BACKGROUND: Schistosomiasis is an important parasitic disease in Kenya. Decreasing susceptibility of schistosomes to praziquantel, the major drug used to reduce disease morbidity, has made assessment of new antischistosomal drugs a priority. We aimed to assess the safety and efficacy of an artesunate-based combination drug in the treatment of schistosomiasis. METHODS: In this open-label randomised trial in Rarieda district of western Kenya, we enrolled school children (aged 6-15 years) who had Schistosoma mansoni infection according to duplicate Kato-Katz thick smears from a stool sample. Computer-generated block randomisation was used to assign children (1:1) to receive artesunate (100 mg) with sulfalene (also known as sulfamethoxypyrazine; 250 mg) plus pyrimethamine (12.5 mg) as one dose every 24 h for 3 days or one dose of praziquantel (40 mg/kg per day). The primary efficacy endpoint was the number of participants cured 28 days after treatment. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01054651. RESULTS: Between October and December, 2009, 212 children were enrolled and assigned to receive artesunate with sulfalene plus pyrimethamine (n=106) or praziquantel (n=106). 69 patients (65%) were cured in the praziquantel treatment group compared with 15 (14%) in the artesunate with sulfalene plus pyrimethamine treatment group (p<0.0001). Adverse events were less common in patients taking artesunate with sulfalene plus pyrimethamine than in those taking praziquantel (22% [n=23] vs 49% [n=52], p<0.0001), and no drug-related serious adverse events occurred. INTERPRETATION: The standard treatment with praziquantel is more effective than artesunate with sulfalene plus pyrimethamine in the treatment of children with S mansoni infection in western Kenya. Whether artemisinin-based combination therapy has a role in the treatment of schistosomiasis is unclear.
Assuntos
Artemisininas/uso terapêutico , Pirimetamina/uso terapêutico , Esquistossomose mansoni/tratamento farmacológico , Sulfaleno/uso terapêutico , Adolescente , Amebicidas/efeitos adversos , Amebicidas/uso terapêutico , Animais , Antiprotozoários/efeitos adversos , Antiprotozoários/uso terapêutico , Artemisininas/efeitos adversos , Artesunato , Criança , Pré-Escolar , Quimioterapia Combinada , Feminino , Humanos , Lactente , Quênia , Masculino , Pirimetamina/efeitos adversos , Schistosoma mansoni , Esquistossomose mansoni/classificação , Sulfaleno/efeitos adversosRESUMO
BACKGROUND: Previous studies suggest that humans can acquire immunity to reinfection with schistosomes, most probably due to immunologic mechanisms acquired after exposure to dying schistosome worms. METHODOLOGY/PRINCIPAL FINDINGS: We followed longitudinally two cohorts of adult males occupationally exposed to Schistosoma mansoni by washing cars (120 men) or harvesting sand (53 men) in Lake Victoria. Men were treated with praziquantel each time S. mansoni infection was detected. In car washers, a significant increase in resistance to reinfection, as measured by the number of cars washed between cure and reinfection, was observed after the car washers had experienced, on average, seven cures. In the car washers who developed resistance, the level of schistosome-specific IgE increased between baseline and the time at which development of resistance was first evidenced. In the sand harvesters, a significant increase in resistance, as measured by the number of days worked in the lake between cure and reinfection, was observed after only two cures. History of exposure to S. mansoni differed between the two cohorts, with the majority of sand harvesters being lifelong residents of a village endemic for S. mansoni and the majority of car washers having little exposure to the lake before they began washing cars. Immune responses at study entry were indicative of more recent infections in car washers and more chronic infections in sand harvesters. CONCLUSIONS/SIGNIFICANCE: Resistance to reinfection with S. mansoni can be acquired or augmented by adults after multiple rounds of reinfection and cure, but the rate at which resistance is acquired by this means depends on immunologic status and history of exposure to S. mansoni infection.
Assuntos
Exposição Ocupacional , Schistosoma mansoni/imunologia , Esquistossomose mansoni/imunologia , Adulto , Animais , Anticorpos Antiprotozoários/sangue , Antiprotozoários/uso terapêutico , Estudos de Coortes , Humanos , Imunoglobulina E/sangue , Estudos Longitudinais , Masculino , Praziquantel/uso terapêutico , Esquistossomose mansoni/tratamento farmacológico , Prevenção Secundária , Adulto JovemRESUMO
Flow cytometric analyses were performed to evaluate HLA-DR (+) activated T lymphocytes (Tact; CD3 (+)/CD4 (+)/CD25(medium)) and T regulatory cells (Treg; CD3 (+)/CD4(+)/CD25(high)) in the circulation of children 8-10 years of age living in an area endemic for both Plasmodium falciparum and Schistosoma mansoni in western Kenya. Those children with only S. mansoni had a higher mean percentage of HLA-DR (+) Tact than those who were co-infected with these two intravascular parasites. The proportion of circulating Treg was comparable in children with only schistosomiasis and both schistosomiasis and malaria. However, the mean level of memory Treg (Treg expressing CD45RO (+)) in those with dual infections was lower than in children with schistosomiasis alone. These imbalances in Tact and Treg memory subsets in children infected with both schistosomiasis and malaria may be related to the differential morbidity or course of infection attributed to coinfections with these parasites.