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1.
BMC Health Serv Res ; 24(1): 597, 2024 May 07.
Article in English | MEDLINE | ID: mdl-38715044

ABSTRACT

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.


Subject(s)
Caregivers , Counseling , Qualitative Research , Rural Population , Humans , Kenya , Caregivers/psychology , Counseling/methods , Infant , Female , Male , Adult , Interviews as Topic
2.
Am J Trop Med Hyg ; 110(4): 677-680, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38460198

ABSTRACT

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.


Subject(s)
Anthelmintics , Artemisinins , Schistosomiasis mansoni , Sulfalene , Child , Animals , Humans , Praziquantel/adverse effects , Artesunate/therapeutic use , Schistosoma mansoni , Kenya , Sulfalene/pharmacology , Sulfalene/therapeutic use , Pyrimethamine/therapeutic use , Artemisinins/adverse effects , Drug Therapy, Combination , Schistosomiasis mansoni/drug therapy , Treatment Outcome , Anthelmintics/therapeutic use
3.
Trials ; 24(1): 763, 2023 Nov 27.
Article in English | MEDLINE | ID: mdl-38012787

ABSTRACT

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.


Subject(s)
Anthelmintics , Artemisinins , Schistosomiasis mansoni , Schistosomiasis , Adult , Animals , Child , Humans , Artemisinins/adverse effects , Artesunate/adverse effects , Drug Therapy, Combination , Praziquantel/adverse effects , Randomized Controlled Trials as Topic , Reinfection/chemically induced , Reinfection/drug therapy , Schistosoma mansoni , Schistosomiasis/drug therapy , Schistosomiasis mansoni/diagnosis , Schistosomiasis mansoni/drug therapy , Schistosomiasis mansoni/chemically induced , Treatment Outcome , Equivalence Trials as Topic
4.
BMC Vet Res ; 18(1): 363, 2022 Oct 01.
Article in English | MEDLINE | ID: mdl-36183113

ABSTRACT

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.


Subject(s)
Dog Diseases , Rabies Vaccines , Rabies , Adjuvants, Immunologic/pharmacology , Alum Compounds , Animals , Anti-Inflammatory Agents , Biomarkers , Case-Control Studies , Clinical Trials, Veterinary as Topic , Cytokines , Dog Diseases/epidemiology , Dog Diseases/prevention & control , Dogs , Female , Humans , Male , Rabies/epidemiology , Rabies/prevention & control , Rabies/veterinary , Vaccination/veterinary
5.
Trials ; 23(1): 449, 2022 Jun 01.
Article in English | MEDLINE | ID: mdl-35650583

ABSTRACT

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.


Subject(s)
Child Nutrition Disorders , Malnutrition , Burkina Faso , Child , Child Nutrition Disorders/diagnosis , Child Nutrition Disorders/prevention & control , Child, Preschool , Counseling , Gardening , Gardens , Humans , Infant , Kenya , Malnutrition/diagnosis , Malnutrition/prevention & control , Multicenter Studies as Topic , Nutritional Status , Randomized Controlled Trials as Topic
7.
PLoS Negl Trop Dis ; 12(8): e0006710, 2018 08.
Article in English | MEDLINE | ID: mdl-30089120

ABSTRACT

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.


Subject(s)
Immune Reconstitution Inflammatory Syndrome/diagnosis , Immune Reconstitution Inflammatory Syndrome/etiology , Matrix Metalloproteinases/metabolism , Schistosomiasis mansoni/complications , Tissue Inhibitor of Metalloproteinases/metabolism , Adult , Animals , Biomarkers , Case-Control Studies , Cohort Studies , Coinfection , Female , HIV Infections , Humans , Kenya/epidemiology , Male , Matrix Metalloproteinases/blood , Schistosoma mansoni , Schistosomiasis mansoni/epidemiology , Schistosomiasis mansoni/immunology , Tissue Inhibitor of Metalloproteinases/blood
8.
Front Immunol ; 9: 1402, 2018.
Article in English | MEDLINE | ID: mdl-29967622

ABSTRACT

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.

9.
Am J Trop Med Hyg ; 89(1): 42-5, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23669231

ABSTRACT

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.


Subject(s)
Anti-HIV Agents/therapeutic use , CD4 Lymphocyte Count , Feces/parasitology , HIV Infections/complications , Parasite Egg Count , Schistosomiasis mansoni/complications , Adult , Animals , Anthelmintics/therapeutic use , Coinfection/drug therapy , Coinfection/parasitology , Coinfection/virology , Feces/virology , HIV Infections/drug therapy , HIV Infections/parasitology , HIV-1 , Humans , Praziquantel/therapeutic use , Schistosoma mansoni , Schistosomiasis mansoni/drug therapy , Schistosomiasis mansoni/parasitology , Schistosomiasis mansoni/virology
10.
Lancet Infect Dis ; 10(9): 603-11, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20705516

ABSTRACT

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.


Subject(s)
Artemisinins/therapeutic use , Pyrimethamine/therapeutic use , Schistosomiasis mansoni/drug therapy , Sulfalene/therapeutic use , Adolescent , Amebicides/adverse effects , Amebicides/therapeutic use , Animals , Antiprotozoal Agents/adverse effects , Antiprotozoal Agents/therapeutic use , Artemisinins/adverse effects , Artesunate , Child , Child, Preschool , Drug Therapy, Combination , Female , Humans , Infant , Kenya , Male , Pyrimethamine/adverse effects , Schistosoma mansoni , Schistosomiasis mansoni/classification , Sulfalene/adverse effects
11.
J Infect Dis ; 202(3): 399-405, 2010 Aug 15.
Article in English | MEDLINE | ID: mdl-20560767

ABSTRACT

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.


Subject(s)
Antibodies, Helminth/blood , B-Lymphocytes/immunology , Immunoglobulin E/blood , Receptors, IgE/analysis , Schistosoma mansoni/immunology , Schistosomiasis mansoni/immunology , Animals , Anthelmintics/therapeutic use , B-Lymphocytes/chemistry , Child , Female , Humans , Kenya , Longitudinal Studies , Male , Praziquantel/therapeutic use , Recurrence , Schistosomiasis mansoni/drug therapy
12.
PLoS Negl Trop Dis ; 4(3): e637, 2010 Mar 23.
Article in English | MEDLINE | ID: mdl-20351784

ABSTRACT

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.


Subject(s)
Occupational Exposure , Schistosoma mansoni/immunology , Schistosomiasis mansoni/immunology , Adult , Animals , Antibodies, Protozoan/blood , Antiprotozoal Agents/therapeutic use , Cohort Studies , Humans , Immunoglobulin E/blood , Longitudinal Studies , Male , Praziquantel/therapeutic use , Schistosomiasis mansoni/drug therapy , Secondary Prevention , Young Adult
13.
Am J Trop Med Hyg ; 80(3): 475-8, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19270301

ABSTRACT

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.


Subject(s)
Malaria, Falciparum/complications , Malaria, Falciparum/immunology , Schistosomiasis mansoni/complications , Schistosomiasis mansoni/immunology , T-Lymphocyte Subsets/physiology , Animals , Child , Female , Flow Cytometry , Humans , Male , Plasmodium falciparum/immunology , Schistosoma mansoni/immunology
14.
Am J Trop Med Hyg ; 77(4): 676-82, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17978070

ABSTRACT

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.


Subject(s)
Praziquantel/therapeutic use , Schistosoma mansoni/immunology , Schistosomiasis mansoni/drug therapy , Schistosomiasis mansoni/immunology , T-Lymphocytes, Regulatory/immunology , Adolescent , Adult , Animals , Anthelmintics/therapeutic use , CD4-Positive T-Lymphocytes/immunology , Eosinophilia/immunology , HIV Seropositivity/immunology , HIV-1/immunology , Humans , Interleukin-2 Receptor alpha Subunit/immunology , Leukocyte Common Antigens/biosynthesis , Leukocyte Common Antigens/immunology , Male , Middle Aged , T-Lymphocytes, Regulatory/pathology
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