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1.
Malar J ; 23(1): 1, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38166910

RESUMO

BACKGROUND: Patients' adherence to artemisinin-based combination therapy (ACT) is a malaria control strategy. Studies report varied experiences regarding patients' adherence to ACT. The study aimed at determining factors influencing patients' adherence to ACT for malaria in Kamuli, Uganda. METHODS: In a longitudinal study, 1266 participants at 8 public health facilities were enrolled. Equal numbers (422) were assigned to the three arms (no follow-up, day 2 and day 4). To establish the mean difference between groups, Student t-test was used and a chi-square test was used for proportionality. A multivariate logistic regression analysis was used to establish the influence of predictor variables on the dependent variable. Statistical significance was established at p < 0.05. RESULTS: A total of 844 patients were analysed. The median age was 20 years, majority (64.3%) were females. Overall patients' adherence was 588/844 (69.7%). At bivariate level, age (t-test = 2.258, p = 0.024), household head (χ2 = 14.484, p = 0.002), employment status (χ2 = 35.886, p < 0.0001), patients' preference of ACT to other anti-malarials (χ2 = 15.981, p < 0.0001), giving a patient/caregiver instructions on how to take the medication (χ2 = 7.134, p = 0.011), being satisfied with getting ACT at facility (χ2 = 48.261, p < 0.0001), patient/caregiver knowing the drug prescribed (χ2 = 5.483, p = 0.019), patient history of saving ACT medicines (χ2 = 39.242, p < 0.0001), and patient ever shared ACT medicines (χ2 = 30.893, p < 0.0001) were all associated with patients' adherence to ACT. Multivariate analysis demonstrated that adhering to ACT is 3.063 times higher for someone satisfied with getting ACT at the facility (OR = 3.063; p < 0.0001), 4.088 times for someone with history of saving ACT medicines (OR = 4.088; p < 0.0001), 2.134 times for someone who shared ACT (OR = 2.134; p = 0.03), and 2.817 times for someone with a household head (OR = 2.817; p = 0.008). CONCLUSION: Patients' adherence to ACT is generally good in the studied population. However, patients' tendencies to save ACT for future use and sharing among family members is a threat, amidst the benefits associated with adherence. There is a need to educate all about adherence to medicines as prescribed, and tighten government medicine supply chain to avoid stock-outs.


Assuntos
Antimaláricos , Artemisininas , Malária , Feminino , Humanos , Adulto Jovem , Adulto , Masculino , Uganda , Estudos Longitudinais , Artemisininas/uso terapêutico , Malária/tratamento farmacológico , Malária/prevenção & controle , Malária/epidemiologia , Antimaláricos/uso terapêutico , Combinação de Medicamentos , Quimioterapia Combinada
2.
Malar J ; 23(1): 81, 2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38493098

RESUMO

BACKGROUND: Vector surveillance is among the World Health Organization global vector control response (2017-2030) pillars. Human landing catches are a gold standard but difficult to implement and potentially expose collectors to malaria infection. Other methods like light traps, pyrethrum spray catches and aspiration are less expensive and less risky to collectors. METHODS: Three mosquito sampling methods (UV light traps, CDC light traps and Prokopack aspiration) were evaluated against human landing catches (HLC) in two villages of Rarieda sub-county, Siaya County, Kenya. UV-LTs, CDC-LTs and HLCs were conducted hourly between 17:00 and 07:00. Aspiration was done indoors and outdoors between 07:00 and 11:00 a.m. Analyses of mosquito densities, species abundance and sporozoite infectivity were performed across all sampling methods. Species identification PCR and ELISAs were done for Anopheles gambiae and Anopheles funestus complexes and data analysis was done in R. RESULTS: Anopheles mosquitoes sampled from 608 trapping efforts were 5,370 constituting 70.3% Anopheles funestus sensu lato (s.l.), 19.7% Anopheles coustani and 7.2% An. gambiae s.l. 93.8% of An. funestus s.l. were An. funestus sensu stricto (s.s.) and 97.8% of An. gambiae s.l. were Anopheles arabiensis. Only An. funestus were sporozoite positive with 3.1% infection prevalence. Indoors, aspiration captured higher An. funestus (mean = 6.74; RR = 8.83, P < 0.001) then UV-LT (mean = 3.70; RR = 3.97, P < 0.001) and CDC-LT (mean = 1.74; RR = 1.89, P = 0.03) compared to HLC. UV-LT and CDC-LT indoors captured averagely 0.18 An. arabiensis RR = 5.75, P = 0.028 and RR = 5.87, P = 0.028 respectively. Outdoors, UV-LT collected significantly higher Anopheles mosquitoes compared to HLC (An. funestus: RR = 5.18, P < 0.001; An. arabiensis: RR = 15.64, P = 0.009; An. coustani: RR = 11.65, P < 0.001). Anopheles funestus hourly biting indoors in UV-LT and CDC-LT indicated different peaks compared to HLC. CONCLUSIONS: Anopheles funestus remains the predominant mosquito species. More mosquitoes were collected using aspiration, CDC-LTs and UV-LTs indoors and UV-LTs and CD-LTs outdoors compared to HLCs. UV-LTs collected more mosquitoes than CDC-LTs. The varied trends observed at different times of the night suggest that these methods collect mosquitoes with diverse activities and care must be taken when interpreting the results.


Assuntos
Anopheles , Malária , Animais , Humanos , Anopheles/fisiologia , Quênia/epidemiologia , Mosquitos Vetores/fisiologia , Comportamento Alimentar , Esporozoítos , Controle de Mosquitos/métodos
3.
BMC Womens Health ; 24(1): 327, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38840127

RESUMO

BACKGROUND: Cervical cancer is a leading cause of cancer death among women of reproductive age despite being treatable if it is diagnosed early. Early diagnosis is possible through regular screening through the public health system. However, screening rates remain low in many low- and middle-income countries, including Kenya, where the screening rate currently stands at 16-18%. The low screening rates are attributed to, among other factors, low knowledge about cervical cancer and the available screening options among women of reproductive age. The current study evaluated the effectiveness of dialogue-based community health education by trained community health volunteers (CHVs) in improving cervical cancer knowledge among women of reproductive age (WRA) in rural Kisumu County. METHODS: This was a longitudinal pre- and post-intervention study with a control group. The knowledge of women of reproductive age was assessed at baseline in both the intervention and control groups, followed by dialogue-based community health education in the intervention arm. A final end-line knowledge assessment was performed. The scores at baseline and at the end of the study were compared to assess changes in knowledge due to the intervention. The proportion of WRA with improved knowledge was also calculated, and statistical significance was considered at p ≤ 0.05. RESULTS: There was no significant difference between the participants in the two arms, except for the level of education (p = 0.002). The knowledge of the WRA in the intervention arm improved significantly (p < 0.001) following the dialogue-based educational intervention by the trained CHVs. None of the demographic characteristics were associated with knowledge. CONCLUSION: Dialogue-based educational intervention significantly improved the knowledge of the WRA in the intervention arm, showing its potential to address the knowledge gap in the community.


Assuntos
Agentes Comunitários de Saúde , Educação em Saúde , Conhecimentos, Atitudes e Prática em Saúde , População Rural , Neoplasias do Colo do Útero , Humanos , Feminino , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/prevenção & controle , Quênia , Adulto , Educação em Saúde/métodos , Estudos Longitudinais , Agentes Comunitários de Saúde/educação , Pessoa de Meia-Idade , Detecção Precoce de Câncer/métodos , Adulto Jovem , Adolescente
4.
BMC Genomics ; 24(1): 542, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37704951

RESUMO

BACKGROUND: Plasmodium falciparum malaria is a leading cause of pediatric morbidity and mortality in holoendemic transmission areas. Severe malarial anemia [SMA, hemoglobin (Hb) < 5.0 g/dL in children] is the most common clinical manifestation of severe malaria in such regions. Although innate immune response genes are known to influence the development of SMA, the role of natural killer (NK) cells in malaria pathogenesis remains largely undefined. As such, we examined the impact of genetic variation in the gene encoding a primary NK cell receptor, natural cytotoxicity-triggering receptor 3 (NCR3), on the occurrence of malaria and SMA episodes over time. METHODS: Susceptibility to malaria, SMA, and all-cause mortality was determined in carriers of NCR3 genetic variants (i.e., rs2736191:C > G and rs11575837:C > T) and their haplotypes. The prospective observational study was conducted over a 36 mos. follow-up period in a cohort of children (n = 1,515, aged 1.9-40 mos.) residing in a holoendemic P. falciparum transmission region, Siaya, Kenya. RESULTS: Poisson regression modeling, controlling for anemia-promoting covariates, revealed a significantly increased risk of malaria in carriers of the homozygous mutant allele genotype (TT) for rs11575837 after multiple test correction [Incidence rate ratio (IRR) = 1.540, 95% CI = 1.114-2.129, P = 0.009]. Increased risk of SMA was observed for rs2736191 in children who inherited the CG genotype (IRR = 1.269, 95% CI = 1.009-1.597, P = 0.041) and in the additive model (presence of 1 or 2 copies) (IRR = 1.198, 95% CI = 1.030-1.393, P = 0.019), but was not significant after multiple test correction. Modeling of the haplotypes revealed that the CC haplotype had a significant additive effect for protection against SMA (i.e., reduced risk for development of SMA) after multiple test correction (IRR = 0.823, 95% CI = 0.711-0.952, P = 0.009). Although increased susceptibility to SMA was present in carriers of the GC haplotype (IRR = 1.276, 95% CI = 1.030-1.581, P = 0.026) with an additive effect (IRR = 1.182, 95% CI = 1.018-1.372, P = 0.029), the results did not remain significant after multiple test correction. None of the NCR3 genotypes or haplotypes were associated with all-cause mortality. CONCLUSIONS: Variation in NCR3 alters susceptibility to malaria and SMA during the acquisition of naturally-acquired malarial immunity. These results highlight the importance of NK cells in the innate immune response to malaria.


Assuntos
Anemia , Malária Falciparum , Malária , Humanos , Criança , Anemia/genética , Genótipo , Malária Falciparum/genética , Alelos , Receptor 3 Desencadeador da Citotoxicidade Natural
5.
BMC Cancer ; 23(1): 566, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37340364

RESUMO

BACKGROUND: Epstein Barr virus (EBV)-associated endemic Burkitt's Lymphoma pediatric cancer is associated with morbidity and mortality among children resident in holoendemic Plasmodium falciparum regions in western Kenya. P. falciparum exerts strong selection pressure on sickle cell trait (SCT), alpha thalassemia (-α3.7/αα), glucose-6-phosphate dehydrogenase (G6PD), and merozoite surface protein 2 (MSP-2) variants (FC27, 3D7) that confer reduced malarial disease severity. The current study tested the hypothesis that SCT, (-α3.7/αα), G6PD mutation and (MSP-2) variants (FC27, 3D7) are associated with an early age of EBV acquisition. METHODS: Data on infant EBV infection status (< 6 and ≥ 6-12 months of age) was abstracted from a previous longitudinal study. Archived infant DNA (n = 81) and mothers DNA (n = 70) samples were used for genotyping hemoglobinopathies and MSP-2. The presence of MSP-2 genotypes in maternal DNA samples was used to indicate infant in-utero malarial exposure. Genetic variants were determined by TaqMan assays or standard PCR. Group differences were determined by Chi-square or Fisher's analysis. Bivariate regression modeling was used to determine the relationship between the carriage of genetic variants and EBV acquisition. RESULTS: EBV acquisition for infants < 6 months was not associated with -α3.7/αα (OR = 1.824, P = 0.354), SCT (OR = 0.897, P = 0.881), or G6PD [Viangchan (871G > A)/Chinese (1024 C > T) (OR = 2.614, P = 0.212)] and [Union (1360 C > T)/Kaiping (1388G > A) (OR = 0.321, P = 0.295)]. There was no relationship between EBV acquisition and in-utero exposure to either FC27 (OR = 0.922, P = 0.914) or 3D7 (OR = 0.933, P = 0.921). In addition, EBV acquisition in infants ≥ 6-12 months also showed no association with -α3.7/αα (OR = 0.681, P = 0.442), SCT (OR = 0.513, P = 0.305), G6PD [(Viangchan (871G > A)/Chinese (1024 C > T) (OR = 0.640, P = 0.677)], [Mahidol (487G > A)/Coimbra (592 C > T) (OR = 0.948, P = 0.940)], [(Union (1360 C > T)/Kaiping (1388G > A) (OR = 1.221, P = 0.768)], African A (OR = 0.278, P = 0.257)], or in utero exposure to either FC27 (OR = 0.780, P = 0.662) or 3D7 (OR = 0.549, P = 0.241). CONCLUSION: Although hemoglobinopathies (-α3.7/αα, SCT, and G6PD mutations) and in-utero exposure to MSP-2 were not associated with EBV acquisition in infants 0-12 months, novel G6PD variants were discovered in the population from western Kenya. To establish that the known and novel hemoglobinopathies, and in utero MSP-2 exposure do not confer susceptibility to EBV, future studies with larger sample sizes from multiple sites adopting genome-wide analysis are required.


Assuntos
Infecções por Vírus Epstein-Barr , Hemoglobinopatias , Malária Falciparum , Malária , Criança , Animais , Humanos , Lactente , Herpesvirus Humano 4/genética , Merozoítos , Infecções por Vírus Epstein-Barr/epidemiologia , Infecções por Vírus Epstein-Barr/genética , Quênia/epidemiologia , Malária/epidemiologia , Malária/genética , Polimorfismo Genético
6.
Trop Med Int Health ; 27(8): 669-677, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35700209

RESUMO

OBJECTIVES: We assessed the impact of water, hygiene and sanitation (WASH), maternal, new-born and child health (MNCH), nutrition and early childhood development (ECD) on diarrhoea and microbial quality of water in a resource-constrained rural setting in Kenya. METHODS: Through a controlled intervention study, we tested faecal and water samples collected from both the intervention and control sites before and after the interventions using microbiological, immunological and molecular assays to determine the prevalence of diarrhoeagenic agents and microbial quality of water. Data from the hospital registers were used to estimate all-cause diarrhoea prevalence. RESULTS: After the interventions, we observed a 58.2% (95% CI: 39.4-75.3) decline in all-cause diarrhoea in the intervention site versus a 22.2% (95% CI: 5.9-49.4) reduction of the same in the control site. Besides rotavirus and pathogenic Escherichia coli, the rate of isolation of other diarrhoea-causing bacteria declined substantially in the intervention site. The microbial quality of community and household water improved considerably in both the intervention (81.9%; 95% CI: 74.5%-87.8%) and control (72.5%; 95% CI: 64.2%-80.5%) sites with the relative improvements in the intervention site being slightly larger. CONCLUSIONS: The integrated WASH, MNCH, nutrition and ECD interventions resulted in notable decline in all-cause diarrhoea and improvements in water quality in the rural resource-limited population in Kenya. This indicates a direct public health impact of the interventions and provides early evidence for public health policy makers to support the sustained implementation of these interventions.


Assuntos
Higiene , Saneamento , Criança , Pré-Escolar , Diarreia/epidemiologia , Diarreia/prevenção & controle , Humanos , Lactente , Quênia/epidemiologia , Saneamento/métodos , Qualidade da Água
7.
Malar J ; 21(1): 129, 2022 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-35459178

RESUMO

BACKGROUND: Accurate malaria diagnosis and appropriate treatment at local health facilities are critical to reducing morbidity and human reservoir of infectious gametocytes. The current study assessed the accuracy of malaria diagnosis and treatment practices in three health care facilities in rural western Kenya. METHODS: The accuracy of malaria detection and treatment recommended compliance was monitored in two public and one private hospital from November 2019 through March 2020. Blood smears from febrile patients were examined by hospital laboratory technicians and re-examined by an expert microscopists thereafter subjected to real-time polymerase chain reaction (RT-PCR) for quality assurance. In addition, blood smears from patients diagnosed with malaria rapid diagnostic tests (RDT) and presumptively treated with anti-malarial were re-examined by an expert microscopist. RESULTS: A total of 1131 febrile outpatients were assessed for slide positivity (936), RDT (126) and presumptive diagnosis (69). The overall positivity rate for Plasmodium falciparum was 28% (257/936). The odds of slide positivity was higher in public hospitals, 30% (186/624, OR:1.44, 95% CI = 1.05-1.98, p < 0.05) than the private hospital 23% (71/312, OR:0.69, 95% CI = 0.51-0.95, p < 0.05). Anti-malarial treatment was dispensed more at public hospitals (95.2%, 177/186) than the private hospital (78.9%, 56/71, p < 0.0001). Inappropriate anti-malarial treatment, i.e. artemether-lumefantrine given to blood smear negative patients was higher at public hospitals (14.6%, 64/438) than the private hospital (7.1%, 17/241) (p = 0.004). RDT was the most sensitive (73.8%, 95% CI = 39.5-57.4) and specific (89.2%, 95% CI = 78.5-95.2) followed by hospital microscopy (sensitivity 47.6%, 95% CI = 38.2-57.1) and specificity (86.7%, 95% CI = 80.8-91.0). Presumptive diagnosis had the lowest sensitivity (25.7%, 95% CI = 13.1-43.6) and specificity (75.0%, 95% CI = 50.6-90.4). RDT had the highest non-treatment of negatives [98.3% (57/58)] while hospital microscopy had the lowest [77.3% (116/150)]. Health facilities misdiagnosis was at 27.9% (77/276). PCR confirmed 5.2% (4/23) of the 77 misdiagnosed cases as false positive and 68.5% (37/54) as false negative. CONCLUSIONS: The disparity in malaria diagnosis at health facilities with many slide positives reported as negatives and high presumptive treatment of slide negative cases, necessitates augmenting microscopic with RDTs and calls for Ministry of Health strengthening supportive infrastructure to be in compliance with treatment guidelines of Test, Treat, and Track to improve malaria case management.


Assuntos
Antimaláricos , Malária Falciparum , Malária , Antimaláricos/uso terapêutico , Artemeter/uso terapêutico , Combinação Arteméter e Lumefantrina/uso terapêutico , Testes Diagnósticos de Rotina , Febre , Pessoal de Saúde , Humanos , Quênia , Malária/diagnóstico , Malária/tratamento farmacológico , Malária Falciparum/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real , População Rural , Sensibilidade e Especificidade
8.
BMC Infect Dis ; 22(1): 768, 2022 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-36192672

RESUMO

BACKGROUND: Malaria remains a public health problem in Kenya despite sustained interventions deployed by the government. One of the major impediments to effective malaria control is a lack of accurate diagnosis and effective treatment. This study was conducted to assess clinical malaria incidence and treatment seeking profiles of febrile cases in western Kenya. METHODS: Active case detection of malaria was carried out in three eco-epidemiologically distinct zones topologically characterized as lakeshore, hillside, and highland plateau in Kisumu County, western Kenya, from March 2020 to March 2021. Community Health Volunteers (CHVs) conducted biweekly visits to residents in their households to interview and examine for febrile illness. A febrile case was defined as an individual having fever (axillary temperature ≥ 37.5 °C) during examination or complaints of fever and other nonspecific malaria related symptoms 1-2 days before examination. Prior to the biweekly malaria testing by the CHVs, the participants' treatment seeking methods were based on their behaviors in response to febrile illness. In suspected malaria cases, finger-prick blood samples were taken and tested for malaria parasites with ultra-sensitive Alere® malaria rapid diagnostic tests (RDT) and subjected to real-time polymerase chain reaction (RT-PCR) for quality control examination. RESULTS: Of the total 5838 residents interviewed, 2205 residents had high temperature or reported febrile illness in the previous two days before the visit. Clinical malaria incidence (cases/1000people/month) was highest in the lakeshore zone (24.3), followed by the hillside (18.7) and the highland plateau zone (10.3). Clinical malaria incidence showed significant difference across gender (χ2 = 7.57; df = 2, p = 0.0227) and age group (χ2 = 58.34; df = 4, p < 0.0001). Treatment seeking patterns of malaria febrile cases showed significant difference with doing nothing (48.7%) and purchasing antimalarials from drug shops (38.1%) being the most common health-seeking pattern among the 2205 febrile residents (χ2 = 21.875; df = 4, p < 0.0001). Caregivers of 802 school-aged children aged 5-14 years with fever primarily sought treatment from drug shops (28.9%) and public hospitals (14.0%), with significant lower proportions of children receiving treatment from traditional medication (2.9%) and private hospital (4.4%) (p < 0.0001). There was no significant difference in care givers' treatment seeking patterns for feverish children under the age of five (p = 0.086). Residents with clinical malaria cases in the lakeshore and hillside zones sought treatment primarily from public hospitals (61.9%, 60/97) traditional medication (51.1%, 23/45) respectively (p < 0.0001). However, there was no significant difference in the treatment seeking patterns of highland plateau residents with clinical malaria (p = 0.431).The main factors associated with the decision to seek treatment were the travel distance to the health facility, the severity of the disease, confidence in the treatment, and affordability. CONCLUSION: Clinical malaria incidence remains highest in the Lakeshore (24.3cases/1000 people/month) despite high LLINs coverage (90%). The travel distance to the health facility, severity of disease and affordability were mainly associated with 80% of residents either self-medicating or doing nothing to alleviate their illness. The findings of this study suggest that the Ministry of Health should strengthen community case management of malaria by providing supportive supervision of community health volunteers to advocate for community awareness, early diagnosis, and treatment of malaria.


Assuntos
Antimaláricos , Malária , Antimaláricos/uso terapêutico , Criança , Febre/tratamento farmacológico , Febre/epidemiologia , Febre/etiologia , Humanos , Incidência , Recém-Nascido , Quênia/epidemiologia , Malária/diagnóstico , Malária/tratamento farmacológico , Malária/epidemiologia
9.
BMC Infect Dis ; 21(1): 329, 2021 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-33827455

RESUMO

BACKGROUND: In Plasmodium falciparum infection, clinical conditions such as anaemia, thrombocytopenia and leukocytosis are common. Mutation in haemoglobin sub-unit beta gene (HBB) may be a genetic factor responsible for these haematological changes during infection. However, the contributions of the carriage of different HBB genotypes on these changes remain largely unknown. METHODOLOGY: In this cross-sectional study, we evaluated haematological abnormalities in P. falciparum-infected children (n = 217, aged 1-192 months) with different haemoglobin sub-unit beta (HBB) genotypes (HbAA, HbAS and HbSS). Children with acute febrile conditions were recruited at Jaramogi Oginga Odinga Teaching and Referral Hospital at the outpatient clinic. Haematological parameters were determined using Beckman Coulter counter ACTdiff2™ while HBB genotyping was done using TaqMan® SNP genotyping assay. Chi-square (χ2) was used to determine differences between proportions. Differences in haematological parameters were compared across groups using Kruskal Wallis test and between groups using Mann Whitney U test. Partial correlation test was used to determine correlation between haematological parameters and sickle cell genotypes while controlling for age and sex. RESULTS: Haemoglobin (Hb), [median (IQR); 7.3 (1.3), P = 0.001], haematocrit (HCT), [median (IQR); 26.4 (4.4), P = 0.009], red blood cells (RBC), [median (IQR); 3.2 (1.7), P = 0.048] were markedly reduced in HbSS, however, red cell distribution with (RDW) [median (IQR); 14.9 (3.3), P = 0.030] was increased in malaria infected children with HbSS. Severe anaemia was highest in HbSS (23.1%) followed by HbAA (8.6%) and HbAS (7.1%). There were no differences in platelet count (P = 0.399) hence no severe thrombocytopeania across the genotypes. Leukocytosis was highest in HbSS (69.2%), 42% in HbAS and 31% in HbAA. The RBC, HCT and Hb had negative correlation with RDW in HbSS in malarial-infected children (r = - 0.725, P = 0.008), (r = - 0.718, P = 0.009) and (r = - 0.792, P = 0.002), respectively. CONCLUSION: Our study reveals that anaemia is the most common abnormality in malaria-infected children with carriage of HbSS. The RBC, HCT and Hb concentration decrease with increase in RDW levels in infected children with carriage of HbSS compared to other HBB genotypes. Therefore, carriage of HbSS genotype is correlated with severity of haematological abnormalities.


Assuntos
Anemia Falciforme/sangue , Malária Falciparum/sangue , Adolescente , Anemia Falciforme/complicações , Anemia Falciforme/genética , Criança , Pré-Escolar , Estudos Transversais , Contagem de Eritrócitos , Feminino , Genótipo , Hematócrito , Hemoglobinas/genética , Humanos , Lactente , Quênia , Leucocitose , Malária Falciparum/complicações , Malária Falciparum/genética , Masculino , Contagem de Plaquetas
10.
J Hum Genet ; 65(2): 99-113, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31664161

RESUMO

Cyclooxygenase-2 [(COX-2) or prostaglandin endoperoxide H2 synthase-2 (PTGS-2)] induces the production of prostaglandins as part of the host-immune response to infections. Although a number of studies have demonstrated the effects of COX-2 promoter variants on autoimmune and inflammatory diseases, their role in malaria remains undefined. As such, we investigated the relationship between four COX-2 promoter variants (COX-2 -512 C > T, -608 T > C, -765 G > C, and -1195 A > G) and susceptibility to malaria and severe malarial anemia (SMA) upon enrollment and longitudinally over a 36-month follow-up period. All-cause mortality was also explored. The investigation was carried out in children (n = 1081, age; 2-70 months) residing in a holoendemic Plasmodium falciparum transmission region of western Kenya. At enrollment, genotypes/haplotypes (controlling for anemia-promoting covariates) did not reveal any strong effects on susceptibility to either malaria or SMA. Longitudinal analyses showed decreased malaria episodes in children who inherited the -608 CC mutant allele (RR = 0.746, P = 1.811 × 10-4) and -512C/-608T/-765G/-1195G (CTGG) haplotype (RR = 0.856, P = 0.011), and increased risk in TTCA haplotype carriers (RR = 1.115, P = 0.026). Over the follow-up period, inheritance of the rare TTCG haplotype was associated with enhanced susceptibility to both malaria (RR = 1.608, P = 0.016) and SMA (RR = 5.714, P = 0.004), while carriage of the rare TTGG haplotype increased the risk of malaria (RR = 1.755, P = 0.007), SMA (RR = 8.706, P = 3.97 × 10-4), and all-cause mortality (HR = 110.000, P = 0.001). Collectively, these results show that SNP variations in the COX-2 promoter, and their inherited combinations, are associated with the longitudinal risk of malaria, SMA, and all-cause mortality among children living in a high transmission area for P. falciparum.


Assuntos
Anemia/genética , Ciclo-Oxigenase 2/genética , Malária Falciparum/genética , Malária/genética , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas/genética , Anemia/mortalidade , Criança , Pré-Escolar , Feminino , Predisposição Genética para Doença , Genótipo , Haplótipos , Humanos , Lactente , Quênia , Estudos Longitudinais , Malária/imunologia , Malária/mortalidade , Malária/transmissão , Malária Falciparum/imunologia , Malária Falciparum/mortalidade , Malária Falciparum/transmissão , Masculino , Risco
11.
Malar J ; 19(1): 378, 2020 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-33092587

RESUMO

BACKGROUND: Sulfadoxine-pyrimethamine (SP) is the only anti-malarial drug formulation approved for intermittent preventive treatment in pregnancy (IPTp). However, mutations in the Plasmodium falciparum dhfr (Pfdhfr) and dhps (Pfdhps) genes confer resistance to pyrimethamine and sulfadoxine, respectively. Here, the frequencies of SP resistance-associated mutations from 2005 to 2018 were compared in samples from Kenyan children with malaria residing in a holoendemic transmission region. METHODS: Partial sequences of the Pfdhfr and Pfdhps genes were amplified and sequenced from samples collected in 2005 (n = 81), 2010 (n = 95), 2017 (n = 43), and 2018 (n = 55). The frequency of known mutations conferring resistance to pyrimethamine and sulfadoxine were estimated and compared. Since artemisinin-based combination therapy (ACT) is the current first-line treatment for malaria, the presence of mutations in the propeller domain of P. falciparum kelch13 gene (Pfk13) linked to ACT-delayed parasite clearance was studied in the 2017/18 samples. RESULTS: Among other changes, the point mutation of Pfdhps S436H increased in frequency from undetectable in 2005 to 28% in 2017/18. Triple Pfdhfr mutant allele (CIRNI) increased in frequency from 84% in 2005 to 95% in 2017/18, while the frequency of Pfdhfr double mutant alleles declined (allele CICNI from 29% in 2005 to 6% in 2017/18, and CNRNI from 9% in 2005 to undetectable in 2010 and 2017/18). Thus, a multilocus Pfdhfr/Pfdhps genotype with six mutations (HGEAA/CIRNI), including Pfdhps S436H, increased in frequency from 2010 to 2017/18. Although none of the mutations associated with ACT-delayed parasite clearance was observed, the Pfk13 mutation A578S, the most widespread Pfk13 SNP found in Africa, was detected in low frequency (2.04%). CONCLUSIONS: There were changes in SP resistance mutant allele frequencies, including an increase in the Pfdhps S436H. Although these patterns seem consistent with directional selection due to drug pressure, there is a lack of information to determine the actual cause of such changes. These results suggest incorporating molecular surveillance of Pfdhfr/Pfdhps mutations in the context of SP efficacy studies for intermittent preventive treatment in pregnancy (IPTp).


Assuntos
Antimaláricos/farmacologia , Resistência a Medicamentos/genética , Plasmodium falciparum/genética , Polimorfismo Genético , Proteínas de Protozoários/genética , Tetra-Hidrofolato Desidrogenase/genética , Criança , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Quênia , Mutação , Plasmodium falciparum/efeitos dos fármacos , Proteínas de Protozoários/metabolismo , Tetra-Hidrofolato Desidrogenase/metabolismo
12.
BMC Infect Dis ; 20(1): 887, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-33238928

RESUMO

BACKGROUND: Sickle cell disease (SCD) is a monogenic disorder due to point mutation in the ß-globin gene resulting in substitution of Valine for Glutamic acid. The SCD is prevalent in P. falciparum endemic regions such as western Kenya. Carriage of different sickle cell genotypes may influence haematological parameter during malaria. Children resident in malaria holoendemic regions suffer more from malaria-related complications and this is moderated by the presence of the SCD. In the current study, we determined the association between sickle cell genotypes and haematological parameters in children with P. falciparum malaria resident in Kisumu County in Western Kenya. METHODOLOGY: Children (n = 217, aged 1-192 months) with acute febrile condition were recruited at Jaramogi Oginga Odinga Teaching and Referral Hospital. Chi-square (χ2) analysis was used to determine differences between proportions. Differences in haematological parameters were compared across groups using Kruskal Wallis test and between groups using Mann Whitney U test. Multivariate logistic regression analysis controlling for infection status was used to determine the association between sickle cell genotypes and haematological parameters. RESULTS: Using HbAA as the reference group, multivariate logistic regression analysis revealed that carriage of HbSS was associated with reduced haemoglobin [OR = 0.310, 95% CI = 0.101-0.956, P = 0.041], reduced haematocrit [OR = 0.318, 95% CI = 0.128-0.793, P = 0.014], reduced RBC count [OR = 0.124, 95% CI = 0.045-0.337, P = 0.001], reduced MCHC [OR = 0.325, 95% CI = 0.118-0.892, P = 0.029], increased leucocytosis [OR = 9.283, 95% CI = 3.167-27.210, P = 0.001] and reduced monocytosis [OR = 0.319, 95% CI = 0.123-0.830, P = 0.019]. However, carriage of HbAS was only associated with increased micro-platelets [OR = 3.629, 95% CI = 1.291-8.276, P = 0.012]. CONCLUSION: Results show that carriage of HbSS in children influence the levels of haemoglobin, haematocrit, RBC, MCHC, WBC and Monocytes. Therefore prior knowledge of HbSS should be considered to improve clinical management of haematological alterations during malaria in children.


Assuntos
Anemia Falciforme/sangue , Anemia Falciforme/epidemiologia , Genótipo , Hemoglobina A/genética , Hemoglobina Falciforme/genética , Malária Falciparum/epidemiologia , Plasmodium falciparum/isolamento & purificação , Adolescente , Anemia Falciforme/genética , Criança , Pré-Escolar , Comorbidade , Estudos Transversais , Contagem de Eritrócitos , Índices de Eritrócitos , Feminino , Hematócrito , Hemoglobina A/análise , Hemoglobina Falciforme/análise , Humanos , Lactente , Quênia/epidemiologia , Leucocitose , Malária Falciparum/parasitologia , Masculino
13.
BMC Infect Dis ; 20(1): 487, 2020 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-32646433

RESUMO

BACKGROUND: Genetic diversity of ABO blood, glucose-6-phosphate dehydrogenase (G6PD) deficiency and haemoglobin type and their ability to protect against malaria vary geographically, ethnically and racially. No study has been carried out in populations resident in malaria regions in western Kenya. METHOD: A total of 574 malaria cases (severe malaria anaemia, SMA = 137 and non-SMA = 437) seeking treatment at Vihiga County and Referral Hospital in western Kenya, were enrolled and screened for ABO blood group, G6PD deficiency and haemoglobin genotyped in a hospital-based cross-sectional study. RESULT: When compared to blood group O, blood groups A, AB and B were not associated with SMA (P = 0.380, P = 0.183 and P = 0.464, respectively). Further regression analysis revealed that the carriage of the intermediate status of G6PD was associated with risk to SMA (OR = 1.52, 95%CI = 1.029-2.266, P = 0.035). There was, however, no association between AS and SS with severe malaria anaemia. Co-occurrence of both haemoglobin type and G6PD i.e. the AA/intermediate was associated with risk to SMA (OR = 1.536, 95%CI = 1.007-2.343, P = 0.046) while the carriage of the AS/normal G6PD was associated with protection against SMA (OR = 0.337, 95%CI = 0.156-0.915, P = 0.031). CONCLUSION: Results demonstrate that blood group genotypes do not have influence on malaria disease outcome in this region. Children in Vihiga with blood group O have some protection against malaria. However, the intermediate status of G6PD is associated with risk of SMA. Further, co-inheritance of sickle cell and G6PD status are important predictors of malaria disease outcome. This implies combinatorial gene function in influencing disease outcome.


Assuntos
Sistema ABO de Grupos Sanguíneos/genética , Genótipo , Deficiência de Glucosefosfato Desidrogenase/genética , Glucosefosfato Desidrogenase/sangue , Hemoglobinas/genética , Malária Falciparum/sangue , Malária Falciparum/epidemiologia , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Quênia/epidemiologia , Malária Falciparum/parasitologia , Masculino , Fenótipo , Plasmodium falciparum/isolamento & purificação , Polimorfismo Genético , Risco , Traço Falciforme/genética
14.
BMC Vet Res ; 16(1): 61, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-32070337

RESUMO

BACKGROUND: Brucellosis in Africa is caused by Brucella species transmitted through contaminated or contacts with infected animals or their carcasses. The disease reduces livestock production and reproduction performance evident by frequent episodes of abortion, still births, swollen testes, weak calves/lambs and swollen joints. However, the socio-economic impacts of these brucellosis-associated symptoms on milk, fat, meat and blood production, infertility, sale value, dowry and costs of treatment has not been evaluated extensively in developing countries. In Baringo County, Kenya, there is a continuous movement of cattle as a result of trade and grazing, which predisposes many herds to brucellosis infection. The objective of this study was to investigate the socio-economic impacts of Brucella infection on production systems for sheep, goats, cattle and camels and explore the impact of brucellosis on livestock production and reproduction performance among livestock keeping communities in Baringo County, Kenya. The study adopted a cross-sectional survey using quantitative data collection methods. RESULTS: Results demonstrated an impact on milk production in suspected brucellosis cases resulting from abortions (OR = 0.151, P < 0.0001) and swollen joints (OR = 2.881, P < 0.0001). In terms of infertility, abortion as a symptom of brucellosis (OR = 0.440, P = 0.002), still birth (OR = 0.628, P = 0.042), and weak calf or lamb (OR = 0.525, P = 0.005) had an impact on infertility. In terms of sale value, abortion (OR = 0.385, P = 0.008), weak calf/lamb (OR = 2.963, P = 0.013) had an impact on sale value. Other analyses demonstrated that for dowry, swollen testes (OR = 5.351, P = 0.032), weak calf and lambs (OR = 0.364, P = 0.019) had a likelihood of reduction of dowry value. Finally, in terms of cost of treatment, abortion (OR = 0.449, P = 0.001), still births (OR = 0.208, P = 0.015), swollen testes (OR = 0.78, P = 0.014), weak calf/lambs (OR = 0.178, P = 0.007) and swollen joints (OR = 0.217, P = 0.003) significantly increased the costs of treatments. There was no impact on fat and meat and blood production. CONCLUSION: Even though there was a huge socio-economic impact on milk production, infertility, sale value, and dowry, it was the costs of treatment that was significantly impacted on all symptoms associated with brucellosis on this community. A 'One Health' approach in tackling the brucellosis menace as a holistic approach is recommended for both humans and their livestock.


Assuntos
Criação de Animais Domésticos/economia , Brucelose/economia , Brucelose/veterinária , Gado , Aborto Animal/economia , Animais , Brucelose/epidemiologia , Estudos Transversais , Indústria de Laticínios/economia , Humanos , Infertilidade/veterinária , Quênia , Casamento , Fatores Socioeconômicos , Inquéritos e Questionários
15.
BMC Vet Res ; 16(1): 133, 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32393374

RESUMO

BACKGROUND: Brucellosis is an emerging yet neglected zoonosis that has been reported in Kenya. Epidemiological data on brucellosis in ruminants is readily accessible; however, reports on brucellosis in pigs remain limited. This study sought to detect Brucella infection in pig serum by both serological and molecular techniques. Serum from 700 pigs randomly collected at a centralized abattoir in Nairobi region, Kenya were screened in parallel, using both Rose Bengal Test (RBT) and competitive Enzyme-Linked Immuno-sorbent Assay (cELISA) for antibodies against Brucella spp. All sera positive by RBT and 16 randomly selected negative samples were further tested using conventional PCR targeting bcsp31 gene and real-time PCR (RT-PCR) assays targeting IS711 and bcsp31 genes. RESULTS: A prevalence of 0.57% (n = 4/700) was estimated using RBT; none of these samples was positive on cELISA. All RBT positive sera were also positive by both PCRs, while two sero-negative samples also tested positive on RT-PCR (n = 6/20). Brucella abortus was detected in four out of the six PCR positive samples through a real-time multiplex PCR. CONCLUSION: The detection of antibodies against Brucella spp. and DNA in serum from slaughterhouse pigs confirm the presence of Brucella in pigs. Therefore, investigation of the epidemiology and role of pigs in the transmission of brucellosis in Kenya is needed. Further targeted studies would be useful to systematically quantify and identify the spp. of Brucella in pigs.


Assuntos
Brucella/isolamento & purificação , Brucelose/veterinária , Doenças dos Suínos/epidemiologia , Matadouros , Animais , Anticorpos Antibacterianos , Brucelose/sangue , Brucelose/epidemiologia , Brucelose/microbiologia , DNA Bacteriano , Ensaio de Imunoadsorção Enzimática/veterinária , Quênia/epidemiologia , Reação em Cadeia da Polimerase/veterinária , Testes Sorológicos/veterinária , Suínos , Doenças dos Suínos/microbiologia
16.
BMC Public Health ; 20(1): 537, 2020 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-32306983

RESUMO

BACKGROUND: During pregnancy or lactating, adequate nutrition for adolescents becomes critical to reduce risks for both child and maternal-related morbidity and mortality. Power dynamics play a massive role in health outcomes. The main objective of this study was to examine the power dynamics in the families and communities and their impact on the pregnant and lactating adolescent girls' access and utilization of nutrition services in Trans-Mara East Sub-County, Narok County. METHODS: A cross-sectional approach that employed mixed methods with both quantitative and qualitative research was adopted. Probability proportionate to size sampling techniques using cluster and simple random methods were used to practically access pregnant or lactating adolescents. Data was collected using questionnaires, in-depth interview and Focus Group Discussion. Quantitative data was analyzed descriptively using frequencies and inferentially using odds ratio and Z-test. Framework analysis was employed to analyze qualitative data. P ≤ 0.05 was considered statistically significant. RESULTS: In the power dynamics analyses, the intrinsic capability (Intrinsic capabilities are those adolescent driven initiatives that facilitate their access to nutrition services) was more likely to decrease awareness by half (OR = 0.52, 95% CI = 0.4-0.7, P < 0.01) whereas extrinsic dependency was likely to increase utilization by 1.2 times (OR = 1.2, 95% CI = 1.0-1.5, P = 0.055). From the stakeholder power matrix, the health personnel had observable visible power to influence access and utilization of nutrition services. Additional results revealed that adolescents who draw their support from significant others were more likely to utilize nutrition services as compared to those who attempted to make their own efforts to seek these services. Furthermore, health personnel have the most influential powers in ensuring adolescents access services and thus the most important actors in the stakeholder matrix. Other actors requiring focus included parents, political figures and governments while stakeholder engagement have higher potential of increasing access and utilization of services through dialogue. CONCLUSIONS: Community access to nutritional services can be increased through use of multiple avenues to reach adolescents, including school-based, health system-based, community-based approaches and even marriage registries. A heightened engagement in the identified stakeholder network is necessary when planning community conversations, to ensure a multi-stakeholder approaches in meeting the nutrition needs of adolescents.


Assuntos
Serviços de Dietética , Lactação/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Poder Psicológico , Gravidez na Adolescência/psicologia , Adolescente , Criança , Estudos Transversais , Feminino , Grupos Focais , Pessoal de Saúde/psicologia , Humanos , Quênia , Casamento , Estado Nutricional , Gravidez , Cuidado Pré-Natal/psicologia , Pesquisa Qualitativa , Inquéritos e Questionários
17.
BMC Med Genet ; 20(1): 140, 2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31420016

RESUMO

BACKGROUND: Severe malarial anemia (SMA) is a leading cause of malaria-related morbidity and mortality in children. The genetic factors that influence development of SMA and inefficient erythropoiesis, a central pathogenic feature of SMA, are only partially understood. METHODS: We performed a pilot Genome-wide Association Study (GWAS) on children with Plasmodium falciparum. The GWAS was performed using the Illumina® Infinium® HD Super Assay in conjunction with Illumina's® Human Omni2.5-8v1 BeadChip (with > 2.45 M markers). Data were analyzed using single SNP logistic regression analysis with an additive model of inheritance controlling for covariates. Results from our pilot global genomics study identified that variation in interleukin (IL)-7 was associated with enhanced risk of SMA. To validate this finding, we investigated the relationship between genotypes and/or haplotypes of two single nucleotide polymorphisms (SNPs) in IL7 [72194 T/C and - 2440 A/G] and susceptibility to both SMA and inefficient erythropoiesis [i.e., reticulocyte production index (RPI) < 2.0 in anemic children (Hb < 11.0 g/dL). Children presenting with P. falciparum malaria (< 3 years, n = 883) were stratified into two groups: Uncomplicated malaria (UM, n = 718) and SMA (n = 165). RESULTS: Regression modeling, controlling for anemia-related confounders, revealed that carriage of the TC genotype at position 72194 T/C was associated with enhanced susceptibility to inefficient erythropoiesis (OR = 1.90; 95% CI 1.09-3.30; P = 0.02) as was homozygous CC (OR 5.14; 95% CI = 1.20-21.99; P = 0.03). Consistent with this finding, individuals with the CA (72194C/-2440A) haplotype had an increased risk of inefficient erythropoiesis (OR = 1.90; 95% CI = 1.10-3.30; P = 0.02), whereas TA haplotype carriers had marginal protection against inefficient erythropoiesis (OR = 0.24; 95% CI = 0.06-1.21; P = 0.05). These observations were supported by Cochran-Armitage trend test for inefficient erythropoiesis (CA > TA > CG; P < 0.01). Although none of the genotype and/or haplotypic variants were significantly associated with SMA, the direction of the risk profiles were consistent with the erythropoiesis results. CONCLUSION: Taken together, variation in IL7 is associated with erythropoietic responses in children with falciparum malaria, a central physiological feature contributing to development of SMA.


Assuntos
Eritropoese/genética , Variação Genética , Interleucina-7/genética , Malária Falciparum/complicações , Anemia/etiologia , Anemia/genética , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Haplótipos , Humanos , Lactente , Quênia , Masculino , Projetos Piloto , Plasmodium falciparum/patogenicidade , Polimorfismo de Nucleotídeo Único
18.
BMC Pregnancy Childbirth ; 19(1): 229, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-31277585

RESUMO

BACKGROUND: An understanding of the association between adolescent nutrition, adolescent pregnancy and their quest for healthcare services may elucidate a basis for intervention and formulation of programs that enhance post-partum and increase the lifespan of the newborn, improve the quality of life and bridge morbidity, mortality and healthcare-associated cost. However, the nutritional needs of pregnant and lactating adolescent girls aged below 10 years resident in Trans Mara East Sub-County, Kenya remained unestablished. The objective of this study was to assess the nutritional needs of pregnant and lactating adolescent girls (under 19) when accessing and utilizing nutritional advice and services in Trans-Mara East Sub-County, Narok County. METHODS: The study adopted a cross-sectional approach that employed mixed methods with both quantitative and qualitative research approaches. Cochran formula was applied to arrive at a minimum of 291 households. Probability proportionate to size sampling techniques using cluster and simple random methods were used to practically access adolescents who are pregnant or lactating. Data was collected using questionnaires, in-depth interview and Focus Group Discussion. Quantitative data was analyzed descriptively using frequencies and inferentially using odds ratio and z-test. Framework analysis was employed to analyze qualitative data. p ≤ 0.05 was considered statistically significant. RESULTS: The study revealed that access of pieces of nutritional-related advice represented by 67.8% was significantly higher than expected frequency of 50%. Nutrition supplementation, food fortification or blending and complementary feeding were significantly below the expectant frequency (p < 0.01) of 50%. Nutrition service areas such as provision and collection of vitamin A and IFAS were significantly lower than expected frequency (p < 0.01). CONCLUSIONS: The most widely utilized were nutrition services that falls within the preventive-focused services followed by curative-focused services. Nutritionist and nurse more likely to increase overall utilization of nutrition services.


Assuntos
Serviços de Saúde do Adolescente , Acessibilidade aos Serviços de Saúde , Serviços de Saúde Materna , Avaliação das Necessidades , Terapia Nutricional , Aceitação pelo Paciente de Cuidados de Saúde , Adolescente , Serviços de Saúde do Adolescente/organização & administração , Serviços de Saúde do Adolescente/estatística & dados numéricos , Fenômenos Fisiológicos da Nutrição do Adolescente , Aleitamento Materno , Criança , Estudos Transversais , Feminino , Promoção da Saúde/métodos , Promoção da Saúde/organização & administração , Promoção da Saúde/estatística & dados numéricos , Acessibilidade aos Serviços de Saúde/organização & administração , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Humanos , Recém-Nascido , Quênia , Lactação , Fenômenos Fisiológicos da Nutrição Materna , Terapia Nutricional/métodos , Terapia Nutricional/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Gravidez , Adulto Jovem
19.
Parasitology ; 145(9): 1235-1242, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29362015

RESUMO

This study assessed the virulence of Trypanosoma evansi, the causative agent of camel trypanosomiasis (surra), affecting mainly camels among other hosts in Africa, Asia and South America, with high mortality and morbidity. Using Swiss white mice, we assessed virulence of 17 T. evansi isolates collected from surra endemic countries. We determined parasitaemia, live body weight, packed cell volume (PCV) and survivorship in mice, for a period of 60 days' post infection. Based on survivorship, the 17 isolates were classified into three virulence categories; low (31-60 days), moderate (11-30 days) and high (0-10 days). Differences in survivorship, PCV and bodyweights between categories were significant and correlated (P < 0.05). Of the 10 Kenyan isolates, four were of low, five moderate and one (Type B) of high virulence. These findings suggest differential virulence between T. evansi isolates. In conclusion, these results show that the virulence of T. evansi may be region specific, the phenotype of the circulating parasite should be considered in the management of surra. There is also need to collect more isolates from other surra endemic regions to confirm this observation.


Assuntos
Parasitemia/veterinária , Trypanosoma/patogenicidade , Tripanossomíase Africana/mortalidade , Animais , Camelus/parasitologia , Camundongos , Trypanosoma/genética , Virulência
20.
BMC Infect Dis ; 17(1): 291, 2017 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-28427357

RESUMO

BACKGROUND: Improved understanding of the molecular mechanisms involved in pediatric severe malarial anemia (SMA) pathogenesis is a crucial step in the design of novel therapeutics. Identification of host genetic susceptibility factors in immune regulatory genes offers an important tool for deciphering malaria pathogenesis. The IL-23/IL-17 immune pathway is important for both immunity and erythropoiesis via its effects through IL-23 receptors (IL-23R). However, the impact of IL-23R variants on SMA has not been fully elucidated. METHODS: Since variation within the coding region of IL-23R may influence the pathogenesis of SMA, the association between IL-23R rs1884444 (G/T), rs7530511 (C/T), and SMA (Hb < 6.0 g/dL) was examined in children (n = 369, aged 6-36 months) with P. falciparum malaria in a holoendemic P. falciparum transmission area. RESULTS: Logistic regression analysis, controlling for confounding factor of anemia, revealed that individual genotypes of IL-23R rs1884444 (G/T) [GT; OR = 1.34, 95% CI = 0.78-2.31, P = 0.304 and TT; OR = 2.02, 95% CI = 0.53-7.74, P = 0.286] and IL-23R rs7530511 (C/T) [CT; OR = 2.6, 95% CI = 0.59-11.86, P = 0.202 and TT; OR = 1.66, 95% CI = 0.84-3.27, P = 0.142] were not associated with susceptibility to SMA. However, carriage of IL-23R rs1884444T/rs7530511T (TT) haplotype, consisting of both mutant alleles, was associated with increased susceptibility to SMA (OR = 1.12, 95% CI = 1.07-4.19, P = 0.030). CONCLUSION: Results presented here demonstrate that a haplotype of non-synonymous IL-23R variants increase susceptibility to SMA in children of a holoendemic P. falciparum transmission area.


Assuntos
Anemia/genética , Haplótipos , Malária Falciparum/complicações , Polimorfismo de Nucleotídeo Único , Receptores de Interleucina/genética , Anemia/etiologia , Pré-Escolar , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Lactente , Quênia , Malária Falciparum/transmissão , Masculino , Mutação
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