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1.
Proc Natl Acad Sci U S A ; 119(36): e2208972119, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-36037372

RESUMO

Children in low-resource settings carry enteric pathogens asymptomatically and are frequently treated with antibiotics, resulting in opportunities for pathogens to be exposed to antibiotics when not the target of treatment (i.e., bystander exposure). We quantified the frequency of bystander antibiotic exposures for enteric pathogens and estimated associations with resistance among children in eight low-resource settings. We analyzed 15,697 antibiotic courses from 1,715 children aged 0 to 2 y from the MAL-ED birth cohort. We calculated the incidence of bystander exposures and attributed exposures to respiratory and diarrheal illnesses. We associated bystander exposure with phenotypic susceptibility of E. coli isolates in the 30 d following exposure and at the level of the study site. There were 744.1 subclinical pathogen exposures to antibiotics per 100 child-years. Enteroaggregative Escherichia coli was the most frequently exposed pathogen, with 229.6 exposures per 100 child-years. Almost all antibiotic exposures for Campylobacter (98.8%), enterotoxigenic E. coli (95.6%), and typical enteropathogenic E. coli (99.4%), and the majority for Shigella (77.6%), occurred when the pathogens were not the target of treatment. Respiratory infections accounted for half (49.9%) and diarrheal illnesses accounted for one-fourth (24.6%) of subclinical enteric bacteria exposures to antibiotics. Bystander exposure of E. coli to class-specific antibiotics was associated with the prevalence of phenotypic resistance at the community level. Antimicrobial stewardship and illness-prevention interventions among children in low-resource settings would have a large ancillary benefit of reducing bystander selection that may contribute to antimicrobial resistance.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Enterobacteriaceae , Exposição Ambiental , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Pré-Escolar , Diarreia/tratamento farmacológico , Diarreia/microbiologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/fisiologia , Infecções por Enterobacteriaceae/tratamento farmacológico , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/transmissão , Humanos , Lactente
2.
Clin Infect Dis ; 72(11): e806-e814, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33033835

RESUMO

BACKGROUND: Prolonged enteropathogen shedding after diarrhea complicates the identification of etiology in subsequent episodes and is an important driver of pathogen transmission. A standardized approach has not been applied to estimate the duration of shedding for a wide range of pathogens. METHODS: We used a multisite birth cohort of children 0-24 months of age from whom diarrheal and monthly nondiarrheal stools were previously tested by quantitative polymerase chain reaction for 29 enteropathogens. We modeled the probability of detection of the etiologic pathogen before and after diarrhea using a log-normal accelerated failure time survival model and estimated the median duration of pathogen carriage as well as differences in subclinical pathogen carriage 60 days after diarrhea onset in comparison to a prediarrhea baseline. RESULTS: We analyzed 3247 etiologic episodes of diarrhea for the 9 pathogens with the highest attributable burdens of diarrhea. The median duration of postdiarrheal carriage varied widely by pathogen, from about 1 week for rotavirus (median, 8.1 days [95% confidence interval {CI}, 6.2-9.6]) to >1 month for Cryptosporidium (39.5 days [95% CI, 30.6-49.0]). The largest increases in subclinical pathogen carriage before and after diarrhea were seen for Cryptosporidium (prevalence difference between 30 days prior and 60 days after diarrhea onset, 0.30 [95% CI, .23-.39]) and Shigella (prevalence difference, 0.21 [95% CI, .16-.27]). CONCLUSIONS: Postdiarrheal shedding was widely variable between pathogens, with strikingly prolonged shedding seen for Cryptosporidium and Shigella. Targeted antimicrobial therapy and vaccination for these pathogens may have a relatively large impact on transmission.


Assuntos
Criptosporidiose , Cryptosporidium , Infecções por Rotavirus , Rotavirus , Criança , Pré-Escolar , Diarreia , Fezes , Humanos , Lactente
3.
Malar J ; 20(1): 188, 2021 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-33865394

RESUMO

BACKGROUND: Malaria remains a global health concern and is endemic in Limpopo, Mpumalanga and KwaZulu Natal Provinces of South Africa, which aims to eliminate malaria by 2025. Community engagement plays a significant role in improving the acceptability and effectiveness of programmes aimed at reducing malaria transmission. The success of such intervention efforts depends on the knowledge, attitudes and practices (KAP) of the community, and understanding the KAP of community residents may support malaria control efforts in the locality. In this context, a cross-sectional household survey to assess community KAP on malaria transmission and prevention in the Ha-Lambani village, Vhembe District, Limpopo Province was conducted. METHODS: Data were collected between November 2018 and May 2019 by questionnaire of 261 consenting adults (213 females and 48 males, aged between 18 and 95 years) selected from different households. Also, a focus group discussion among 13 randomly selected participants was conducted. Pearson's Chi Square test was used to determine statistical differences by village. RESULTS: Study participants (100%, 261/261) were aware of the presence of malaria in their community and 95% associated it with mosquito bites. The local health clinic was the most prominent source of malaria information (85%). Only 22% correctly identified headache, chills and fever as the three most common symptoms of malaria. The majority of participants (98%) knew that effective medication for malaria is available and had a positive treatment-seeking behaviour. Knowledge of malaria prevention measures was high (82%); contrarily, 97% of respondents did not sleep under a bed net the previous night. The focus group data concurred with these results and also revealed that poor bed net use resulted from lack of access to bed nets because community residents could not afford them. CONCLUSIONS: The study demonstrates that participants have appropriate knowledge about malaria transmission and a positive treatment-seeking behaviour. However, economic barriers are responsible for the inadequate use of bed nets. Therefore, distribution of bed nets to the community should be considered to improve practice of malaria prevention measures. Furthermore, knowledge of signs and symptoms and appropriate malaria treatment was limited, and initiatives to improve awareness on these topics should be continued.


Assuntos
Conhecimentos, Atitudes e Prática em Saúde , Malária/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Humanos , Malária/prevenção & controle , Malária/transmissão , Masculino , Pessoa de Meia-Idade , Fatores Socioeconômicos , África do Sul , Adulto Jovem
4.
Environ Sci Technol ; 55(13): 8955-8964, 2021 07 06.
Artigo em Inglês | MEDLINE | ID: mdl-34133882

RESUMO

Health benefits from point-of-use (POU) water treatment devices come only with consistent use. Embedded sensors can measure the consistency of POU-device use and can provide insights about improving it. We demonstrate both potentials with data from SmartSpouts: accelerometer-based sensors embedded in spigot handles that record the duration and timing of use. In the laboratory, most sensor readings correlated well (>0.98) with manually timed water withdrawals. In the field, SmartSpouts measured >60,000 water withdrawals across 232 households in Limpopo, South Africa. Sensors proved critical to understanding consistent use; surveys overestimated it by 53 percentage points. Sensor data showed when households use POU devices (evening peaks and delayed weekend routines) and user preferences (safe storage over filters). We demonstrate analytically and with data that (i) consistent use (e.g., 7 continuous days) is extremely sensitive to single-day use prevalence and (ii) use prevalence affects the performance of contact-time-based POU devices, exemplified with silver tablets. Deployed SmartSpouts had limitations, including memory overflows and confounding device relocation with water withdrawal. Nevertheless, SmartSpouts provided useful and objective data on the prevalence of single-day and consistent use. Considerably less expensive than alternatives, SmartSpouts enable an order of magnitude increase in how many POU-device sensors can be deployed.


Assuntos
Purificação da Água , Características da Família , Prata , África do Sul , Abastecimento de Água
5.
AIDS Res Ther ; 18(1): 1, 2021 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407664

RESUMO

BACKGROUND: South Africa, with one of the highest HIV prevalences in the world, introduced the universal test and treat (UTT) programme in September 2016. Barriers to sustained viral suppression may include drug resistance in the pre-treated population, non-adherence, acquired resistance; pharmacokinetics and pharmacodynamics, and concurrent use of alternative treatments. OBJECTIVE: The purpose of this review is to highlight potential challenges to achieving sustained viral load suppression in South Africa (SA), a major expectation of the UTT initiative. METHODOLOGY: Through the PRISMA approach, published articles from South Africa on transmitted drug resistance; adherence to ARV; host genetic factors in drug pharmacokinetics and pharmacodynamics, and interactions between ARV and herbal medicine were searched and reviewed. RESULTS: The level of drug resistance in the pre-treated population in South Africa has increased over the years, although it is heterogeneous across and within Provinces. At least one study has documented a pre-treated population with moderate (> 5%) or high (> 15%) levels of drug resistance in eight of the nine Provinces. The concurrent use of ARV and medicinal herbal preparation is fairly common in SA, and may be impacting negatively on adherence to ARV. Only few studies have investigated the association between the genetically diverse South African population and pharmacokinetics and pharmacodynamics of ARVs. CONCLUSION: The increasing levels of drug resistant viruses in the pre-treated population poses a threat to viral load suppression and the sustainability of first line regimens. Drug resistance surveillance systems to track the emergence of resistant viruses, study the burden of prior exposure to ARV and the parallel use of alternative medicines, with the goal of minimizing resistance development and virologic failure are proposed for all the Provinces of South Africa. Optimal management of the different drivers of drug resistance in the pre-treated population, non-adherence, and acquired drug resistance will be beneficial in ensuring sustained viral suppression in at least 90% of those on treatment, a key component of the 90-90-90 strategy.


Assuntos
Fármacos Anti-HIV , Infecções por HIV , Resposta Viral Sustentada , Adulto , Fármacos Anti-HIV/uso terapêutico , Criança , Estudos Transversais , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Humanos , Estudos Prospectivos , África do Sul , Carga Viral
6.
J Infect Dis ; 222(11): 1858-1868, 2020 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-31984416

RESUMO

BACKGROUND: The degree of protection conferred by natural immunity is unknown for many enteropathogens, but it is important to support the development of enteric vaccines. METHODS: We used the Andersen-Gill extension of the Cox model to estimate the effects of previous infections on the incidence of subsequent subclinical infections and diarrhea in children under 2 using quantitative molecular diagnostics in the MAL-ED cohort. We used cross-pathogen negative control associations to correct bias due to confounding by unmeasured heterogeneity of exposure and susceptibility. RESULTS: Prior rotavirus infection was associated with a 50% lower hazard (calibrated hazard ratio [cHR], 0.50; 95% confidence interval [CI], 0.41-0.62) of subsequent rotavirus diarrhea. Strong protection was evident against Cryptosporidium diarrhea (cHR, 0.32; 95% CI, 0.20-0.51). There was also protection due to prior infections for norovirus GII (cHR against diarrhea, 0.67; 95% CI, 0.49-0.91), astrovirus (cHR, 0.62; 95% CI, 0.48-0.81), and Shigella (cHR, 0.79; 95% CI, 0.65-0.95). Minimal protection was observed for other bacteria, adenovirus 40/41, and sapovirus. CONCLUSIONS: Natural immunity was generally stronger for the enteric viruses than bacteria, potentially due to less antigenic diversity. Vaccines against major causes of diarrhea may be feasible but likely need to be more immunogenic than natural infection.


Assuntos
Diarreia/imunologia , Imunidade Inata , Adenoviridae , Bactérias , Pré-Escolar , Estudos de Coortes , Criptosporidiose , Cryptosporidium , Diarreia/microbiologia , Diarreia/parasitologia , Diarreia/virologia , Fezes/virologia , Humanos , Lactente , Recém-Nascido , Norovirus , Rotavirus
7.
J Biol Chem ; 294(40): 14591-14602, 2019 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-31375561

RESUMO

Zika virus (ZIKV)3 is an enveloped, single-stranded, positive-sense RNA virus of the Flaviviridae family that has emerged as a public health threat because of its global transmission and link to microcephaly. Currently there is no vaccine for this virus. Conversion of cholesterol to 25-hydroxycholesterol by cholesterol 25-hydroxylase (CH25H) has been shown to have broad antiviral properties. However, the molecular basis of induction of CH25H in humans is not known. Elucidation of signaling and transcriptional events for induction of CH25H expression is critical for designing therapeutic antiviral agents. In this study, we show that CH25H is induced by ZIKV infection or Toll-like receptor stimulation. Interestingly, CH25H is induced by pro-inflammatory cytokines, including IL-1ß, tumor necrosis factor α, and IL-6, and this induction depends on the STAT1 transcription factor. Additionally, we observed that cAMP-dependent transcription factor (ATF3) weakly binds to the CH25H promoter, suggesting cooperation with STAT1. However, ZIKV-induced CH25H was independent of type I interferon. These findings provide important information for understanding how the Zika virus induces innate inflammatory responses and promotes the expression of anti-viral CH25H protein.


Assuntos
Fator 3 Ativador da Transcrição/genética , Fator de Transcrição STAT1/genética , Esteroide Hidroxilases/genética , Infecção por Zika virus/genética , Zika virus/genética , Antivirais/química , Antivirais/metabolismo , Citocinas/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Regulação Enzimológica da Expressão Gênica , Humanos , Inflamação/enzimologia , Inflamação/genética , Inflamação/virologia , Interferon Tipo I/genética , Interleucina-1beta/genética , Interleucina-6/genética , Macrófagos/virologia , Esteroide Hidroxilases/química , Receptores Toll-Like/genética , Fator de Necrose Tumoral alfa/genética , Replicação Viral/genética , Zika virus/patogenicidade , Infecção por Zika virus/enzimologia , Infecção por Zika virus/virologia
8.
AIDS Res Ther ; 17(1): 5, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-32033571

RESUMO

BACKGROUND: Entry inhibitors, such as Maraviroc, hold promise as components of HIV treatment and/or pre-exposure prophylaxis in Africa. Maraviroc inhibits the interaction between HIV Envelope gp120 V3-loop and CCR5 coreceptor. HIV-1 subtype C (HIV-1-C) is predominant in Southern Africa and preferably uses CCR5 co-receptor. Therefore, a significant proportion of HIV-1-C CXCR4 utilizing viruses (X4) may compromise the effectiveness of Maraviroc. This analysis examined coreceptor preferences in early and chronic HIV-1-C infections across Africa. METHODS: African HIV-1-C Envelope gp120 V3-loop sequences sampled from 1988 to 2014 were retrieved from Los Alamos HIV Sequence Database. Sequences from early infections (< 186 days post infection) and chronic infections (> 186 days post infection) were analysed for predicted co-receptor preferences using Geno2Pheno [Coreceptor] 10% FPR, Phenoseq-C, and PSSMsinsi web tools. V3-loop diversity was determined, and viral subtype was confirmed by phylogenetic analysis. National treatment guidelines across Africa were reviewed for Maraviroc recommendation. RESULTS: Sequences from early (n = 6316) and chronic (n = 7338) HIV-1-C infected individuals from 10 and 15 African countries respectively were available for analyses. Overall, 518/6316 (8.2%; 95% CI 0.7-9.3) of early sequences were X4, with Ethiopia and Malawi having more than 10% each. For chronic infections, 8.3% (95% CI 2.4-16.2) sequences were X4 viruses, with Ethiopia, Tanzania, and Zimbabwe having more than 10% each. For sequences from early chronic infections (< 1 year post infection), the prevalence of X4 viruses was 8.5% (95% CI 2.6-11.2). In late chronic infections (≥ 5 years post infection), X4 viruses were observed in 36% (95% CI - 16.3 to 49.9), with two countries having relatively high X4 viruses: South Africa (43%) and Malawi (24%). The V3-loop amino acid sequence were more variable in X4 viruses in chronic infections compared to acute infections, with South Africa, Ethiopia and Zimbabwe showing the highest levels of V3-loop diversity. All sequences were phylogenetically confirmed as HIV-1-C and clustered according to their co-receptor tropism. In Africa, Maraviroc is registered only in South Africa and Uganda. CONCLUSIONS: Our analyses illustrate that X4 viruses are present in significantly similar proportions in early and early chronic HIV-1 subtype C infected individuals across Africa. In contrast, in late chronic infections, X4 viruses increase 3-5 folds. We can draw two inferences from our observations: (1) to enhance the utility of Maraviroc in chronic HIV subtype C infections in Africa, prior virus co-receptor determination is needed; (2) on the flip side, research on the efficacy of CXCR4 antagonists for HIV-1-C infections is encouraged. Currently, the use of Maraviroc is very limited in Africa.


Assuntos
Proteína gp120 do Envelope de HIV/genética , Infecções por HIV/epidemiologia , Infecções por HIV/virologia , HIV-1/classificação , Tropismo Viral/genética , Farmacorresistência Viral Múltipla/genética , Genótipo , Infecções por HIV/transmissão , HIV-1/efeitos dos fármacos , HIV-1/fisiologia , Humanos , Maraviroc/uso terapêutico , Filogenia , Receptores CXCR4 , Receptores de HIV , Análise de Sequência de DNA , África do Sul/epidemiologia
9.
BMC Med Genet ; 20(1): 21, 2019 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-30660178

RESUMO

BACKGROUND: The apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3 (APOBEC3) genes A3D, A3F, A3G and A3H have all been implicated in the restriction of human immunodeficiency virus type 1 (HIV-1) replication. Polymorphisms in these genes are likely to impact viral replication and fitness, contributing to viral diversity. Currently, only a few studies indicate that polymorphisms in the A3 genes may be correlated with infection risk and disease progression. METHODS: To characterize polymorphisms in the coding regions of these APOBEC3 genes in an HIV-1 infected population from the Limpopo Province of South Africa, APOBEC3 gene fragments were amplified from genomic DNA of 192 HIV-1 infected subjects and sequenced on an Illumina MiSeq platform. SNPs were confirmed and compared to SNPs in other populations reported in the 1000 Genome Phase III and HapMap databases, as well as in the ExAC exome database. Hardy-Weinberg Equilibrium was calculated and haplotypes were inferred using the LDlink 3.0 web tool. Linkage Disequilibrium (LD) for these SNPS were calculated in the total 1000 genome and AFR populations using the same tool. RESULTS: Known variants compared to the GRCh37 consensus genome sequence were detected at relatively high frequencies (> 5%) in all of the APOBEC3 genes. A3H showed the most variation, with several of the variants present in both alleles in almost all of the patients. Several minor allele variants (< 5%) were also detected in A3D, A3F and A3G. In addition, novel R6K, L221R and T238I variants in A3D and I117I in A3F were observed. Four, five, four, and three haplotypes were identified for A3D, A3F, A3G, and A3H respectively. CONCLUSIONS: The study showed significant polymorphisms in the APOBEC3D, 3F, 3G and 3H genes in our South African HIV1-infected cohort. In the case of all of these genes, the polymorphisms were generally present at higher frequencies than reported in other 1000 genome populations and in the ExAC exome consortium database .


Assuntos
Desaminase APOBEC-3G/genética , Aminoidrolases/genética , Citidina Desaminase/genética , Citosina Desaminase/genética , Infecções por HIV/genética , Mutação INDEL , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Éxons , Feminino , Frequência do Gene , Testes Genéticos , Infecções por HIV/etnologia , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Análise de Sequência de DNA , África do Sul/etnologia , Adulto Jovem
10.
Bull World Health Organ ; 95(1): 49-61, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-28053364

RESUMO

OBJECTIVE: To describe the frequency and factors associated with antibiotic use in early childhood, and estimate the proportion of diarrhoea and respiratory illnesses episodes treated with antibiotics. METHODS: Between 2009 and 2014, we followed 2134 children from eight sites in Bangladesh, Brazil, India, Nepal, Pakistan, Peru, South Africa and the United Republic of Tanzania, enrolled in the MAL-ED birth cohort study. We documented all antibiotic use from mothers' reports at twice-weekly visits over the children's first two years of life. We estimated the incidence of antibiotic use and the associations of antibiotic use with child and household characteristics. We described treatment patterns for diarrhoea and respiratory illnesses, and identified factors associated with treatment and antibiotic class. FINDINGS: Over 1 346 388 total days of observation, 16 913 courses of antibiotics were recorded (an incidence of 4.9 courses per child per year), with the highest use in South Asia. Antibiotic treatment was given for 375/499 (75.2%) episodes of bloody diarrhoea and for 4274/9661 (44.2%) episodes of diarrhoea without bloody stools. Antibiotics were used in 2384/3943 (60.5%) episodes of fieldworker-confirmed acute lower respiratory tract illness as well as in 6608/16742 (39.5%) episodes of upper respiratory illness. Penicillins were used most frequently for respiratory illness, while antibiotic classes for diarrhoea treatment varied within and between sites. CONCLUSION: Repeated antibiotic exposure was common early in life, and treatment of non-bloody diarrhoea and non-specific respiratory illnesses was not consistent with international recommendations. Rational antibiotic use programmes may have the most impact in South Asia, where antibiotic use was highest.


Assuntos
Antibacterianos/administração & dosagem , Diarreia/tratamento farmacológico , Uso de Medicamentos/estatística & dados numéricos , Saúde Global , Doenças Respiratórias/tratamento farmacológico , Antibacterianos/uso terapêutico , Países em Desenvolvimento , Feminino , Fidelidade a Diretrizes , Humanos , Lactente , Recém-Nascido , Masculino , Guias de Prática Clínica como Assunto , Fatores Socioeconômicos
11.
AIDS Res Ther ; 14(1): 11, 2017 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-28270215

RESUMO

PURPOSE: Occult hepatitis B infection (OBI) among HIV positive patients varies widely in different geographic regions. We undertook a study to determine the prevalence of occult hepatitis B infection among HIV infected individuals visiting a health facility in South West Cameroon and characterized occult HBV strains based on sequence analyses. METHODS: Plasma samples (n = 337), which previously tested negative for hepatitis B surface antigen (HBsAg), were screened for antibodies against hepatitis B core (anti-HBc) and surface (anti-HBs) antigens followed by DNA extraction. A 366 bp region covering the overlapping surface/polymerase gene of HBV was then amplified in a nested PCR and the amplicons sequenced using Sanger sequencing. The resulting sequences were then analyzed for genotypes and for escape and drug resistance mutations. RESULTS: Twenty samples were HBV DNA positive and were classified as OBI giving a prevalence of 5.9%. Out of these, 9 (45%) were anti-HBs positive, while 10 (52.6%) were anti-HBc positive. Additionally, 2 had dual anti-HBs and anti-HBc reactivity, while 6 had no detectable HBV antibodies. Out of the ten samples that were successfully sequenced, nine were classified as genotype E and one as genotype A. Three sequences possessed mutations associated with lamivudine resistance. We detected a number of mutations within the major hydrophilic region of the surface gene where most immune escape mutations occur. CONCLUSIONS: Findings from this study show the presence of hepatitis B in patients without any of the HBV serological markers. Further prospective studies are required to determine the risk factors and markers of OBI.


Assuntos
Soropositividade para HIV/epidemiologia , Soropositividade para HIV/virologia , HIV/isolamento & purificação , Vírus da Hepatite B/isolamento & purificação , Hepatite B/epidemiologia , Hepatite B/virologia , Adolescente , Adulto , Sequência de Bases , Camarões/epidemiologia , Pré-Escolar , Coinfecção/sangue , Coinfecção/epidemiologia , Coinfecção/virologia , Estudos Transversais , DNA Viral/sangue , Farmacorresistência Viral , Feminino , HIV/genética , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Hepatite B/sangue , Hepatite B/tratamento farmacológico , Anticorpos Anti-Hepatite B/sangue , Antígenos do Núcleo do Vírus da Hepatite B/genética , Antígenos de Superfície da Hepatite B/sangue , Antígenos de Superfície da Hepatite B/genética , Vírus da Hepatite B/genética , Humanos , Lamivudina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Mutação , Filogenia , Prevalência , Estudos Prospectivos , Fatores de Risco , Análise de Sequência , Adulto Jovem
12.
AIDS Res Ther ; 14(1): 36, 2017 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-28750647

RESUMO

BACKGROUND: Combination antiretroviral therapy (cART) has significantly reduced HIV morbidity and mortality in both developed and developing countries. However, the sustainability of cART may be compromised by the emergence of viral drug resistance mutations (DRM) and the cellular persistence of proviruses carrying these DRM. This is potentially a more serious problem in resource limited settings. METHODS: DRM were evaluated in individuals with unsuppressed viral loads after first or multiple lines of cART at two sites in rural Limpopo, South Africa. Seventy-two patients with viral loads of >1000 copies/ml were recruited between March 2014 and December 2015. Complete protease (PR) and partial Reverse Transcriptase (RT) sequences were amplified from both plasma RNA and paired proviral DNA from 35 of these subjects. Amplicons were directly sequenced to determine subtype and DRM using the Stanford HIV Drug Resistance Interpretation algorithm. RESULTS: Among the 72 samples, 69 could be PCR amplified from RNA and 35 from both RNA and DNA. Sixty-five (94.2%) viruses were subtype C, while one was subtype B (1.4%), one recombinant K/C, one recombinant C/B and one unclassified. Fifty-eight (84%) sequences carried at least one DRM, while 11 (15.9%) displayed no DRM. DRM prevalence according to drug class was: NRTI 60.8% NNRTI 65.2%, and PI 5.8%. The most common DRMs were; M184V (51.7%), K103N (50%), V106M (20.6%), D67N (13.3%), K65R (12%). The frequency of the DRM tracked well with the frequency of use of medications to which the mutations were predicted to confer resistance. Interestingly, a significant number of subjects showed predicted resistance to the newer NNRTIs, etravirine (33%) and rilpivirine (42%), both of which are not yet available in this setting. The proportion of DRM in RNA and DNA were mostly similar with the exception of the thymidine analogue mutations (TAMs) D67N, K70R, K219QE; and K103N which were slightly more prevalent in DNA than RNA. Subjects who had received cART for at least 5 years were more likely to harbour >2 DRM (p < 0.05) compared to those treated for a shorter period. DRM were more prevalent in this rural setting compared to a neighbouring urban setting. CONCLUSION: We found a very high prevalence of NRTI and NNRTI DRM in patients from rural Limpopo settings with different durations of treatment. The prevalence was significantly higher than those reported in urban settings in South Africa. The dominance of NNRTI based mutations late in treatment supports the use of PI based regimens for second line treatment in this setting. The slight dominance of TAMs in DNA from infected PBMCs compared to plasma virus requires further studies that should include cART subjects with suppressed virus. Such studies will improve our understanding of the pattern of drug resistance and dynamics of viral persistence in these rural settings.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Terapia Antirretroviral de Alta Atividade , Farmacorresistência Viral/genética , Infecções por HIV/tratamento farmacológico , HIV-1/genética , Carga Viral/efeitos dos fármacos , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , HIV-1/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Transcriptase Reversa/uso terapêutico , População Rural , África do Sul , Falha de Tratamento , Adulto Jovem
13.
BMC Public Health ; 17(1): 267, 2017 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-28302095

RESUMO

BACKGROUND: Researchers involved in biomedical community-based projects rarely seek the perspectives of community fieldworkers, who are the 'foot soldiers' in such projects. Understanding the effect of biomedical research on community-based field workers could identify benefits and shortfalls that may be crucial to the success of community-based studies. The present study explored the perceptions of community-based field workers on the effect of the Etiology, Risk Factors and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health and Development Project" (MAL-ED) South Africa on their tangible and intangible capital which together comprise sustainable livelihoods. METHODS: The study was conducted in Dzimauli community in Limpopo Province of South Africa between January-February 2016. The sustainable livelihoods framework was used to query community-based field workers' perspectives of both tangible assets such as income and physical assets and intangible assets such as social capital, confidence, and skills. Data were collected through twenty one individual in-depth interviews and one focus group discussion. Data were analysed using the Thematic Content Analysis approach supported by ATLAS.ti, version 7.5.10 software. RESULTS: All the field workers indicated that they benefitted from the MAL-ED South Africa project. The benefits included intangible assets such as acquisition of knowledge and skills, stronger social capital and personal development. Additionally, all indicated that MAL-ED South Africa provided them with the tangible assets of increased income and physical assets. Observations obtained from the focus group discussion and the community-based leaders concurred with the findings from the in-depth interviews. Additionally, some field workers expressed the desire for training in public relations, communication, problem solving and confidence building. CONCLUSIONS: The MAL-ED South Africa, biomedical research project, had positive effects on tangible and intangible assets that compose the sustainable livelihoods of community-based fieldworkers. However, the field workers expressed the need to acquire social skills to enable them carry out their duties more efficiently.


Assuntos
Pesquisa Biomédica , Agentes Comunitários de Saúde , Declarações Financeiras , Pessoal de Saúde , Renda , Pesquisadores , Capital Social , Adulto , Idoso , Atitude do Pessoal de Saúde , Comunicação , Feminino , Grupos Focais , Humanos , Masculino , Pessoa de Meia-Idade , Percepção , Resolução de Problemas , Relações Públicas , Projetos de Pesquisa , África do Sul , Adulto Jovem
14.
BMC Infect Dis ; 16(1): 523, 2016 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-27682438

RESUMO

BACKGROUND: Malaria is one of the leading causes of morbidity and mortality in children and HIV infection as well as other factors may worsen the situation. This study was aimed at determining the factors influencing malaria parasite prevalence and density as well as anaemia in HIV-infected children in Mutengene, Cameroon from November, 2012 to April, 2013. METHODS: A semi-structured questionnaire was used to record information on socio-demographic factors and use of preventive measures by caregivers of HIV-infected children aged 1-15 years and of both sexes. Venous blood was collected; blood films were prepared and Giemsa-stained for parasite detection and speciation. Haemoglobin concentration was measured and the anaemic status determined. Data was analysed using Epi Info 7 software. RESULTS: A total of 234 children were studied. The overall malaria parasite prevalence was 24.8 % (58) and was significantly higher (31.9 %, P = 0 .004) in females, those who did not implement any preventive measure at all (66.7 %, P = 0.03) and children who used antiretroviral therapy (ART) (28.6 %, P = 0.02) when compared with their respective counterparts. Geometric mean parasite density (GMPD) was significantly higher (3098.4, P = 0.02) in children who presented with fever, had CD4 T cells ≥500 cells/µL (491.3, P = 0.003) and those with moderate anaemia (1658.8, P = 0.03) than their respective counterparts. Although there was no significant difference, GMPD was however higher in males (549.0); those not on ART (635.0) and highest in children <5 years old (633.0) than their respective counterparts. The overall prevalence of anaemia was 49.6 % (116). The value was significantly highest (58.3 %, P = 0.01) in the 11-15 years age group; those with CD4 T cell level 200-499 (72.7 %, P = 0.001) and children with fever (85.7 %, P = 0.01). CONCLUSION: Implementation of proper and integrated malaria preventive measures as well as frequent monitoring of anaemia on prescription of ART could likely improve the health conditions of HIV-infected children thus avoiding malaria-related morbidity and mortality.

15.
PLoS Med ; 12(4): e1001810, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25849352

RESUMO

BACKGROUND: Regional and subtype-specific mutational patterns of HIV-1 transmitted drug resistance (TDR) are essential for informing first-line antiretroviral (ARV) therapy guidelines and designing diagnostic assays for use in regions where standard genotypic resistance testing is not affordable. We sought to understand the molecular epidemiology of TDR and to identify the HIV-1 drug-resistance mutations responsible for TDR in different regions and virus subtypes. METHODS AND FINDINGS: We reviewed all GenBank submissions of HIV-1 reverse transcriptase sequences with or without protease and identified 287 studies published between March 1, 2000, and December 31, 2013, with more than 25 recently or chronically infected ARV-naïve individuals. These studies comprised 50,870 individuals from 111 countries. Each set of study sequences was analyzed for phylogenetic clustering and the presence of 93 surveillance drug-resistance mutations (SDRMs). The median overall TDR prevalence in sub-Saharan Africa (SSA), south/southeast Asia (SSEA), upper-income Asian countries, Latin America/Caribbean, Europe, and North America was 2.8%, 2.9%, 5.6%, 7.6%, 9.4%, and 11.5%, respectively. In SSA, there was a yearly 1.09-fold (95% CI: 1.05-1.14) increase in odds of TDR since national ARV scale-up attributable to an increase in non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance. The odds of NNRTI-associated TDR also increased in Latin America/Caribbean (odds ratio [OR] = 1.16; 95% CI: 1.06-1.25), North America (OR = 1.19; 95% CI: 1.12-1.26), Europe (OR = 1.07; 95% CI: 1.01-1.13), and upper-income Asian countries (OR = 1.33; 95% CI: 1.12-1.55). In SSEA, there was no significant change in the odds of TDR since national ARV scale-up (OR = 0.97; 95% CI: 0.92-1.02). An analysis limited to sequences with mixtures at less than 0.5% of their nucleotide positions­a proxy for recent infection­yielded trends comparable to those obtained using the complete dataset. Four NNRTI SDRMs­K101E, K103N, Y181C, and G190A­accounted for >80% of NNRTI-associated TDR in all regions and subtypes. Sixteen nucleoside reverse transcriptase inhibitor (NRTI) SDRMs accounted for >69% of NRTI-associated TDR in all regions and subtypes. In SSA and SSEA, 89% of NNRTI SDRMs were associated with high-level resistance to nevirapine or efavirenz, whereas only 27% of NRTI SDRMs were associated with high-level resistance to zidovudine, lamivudine, tenofovir, or abacavir. Of 763 viruses with TDR in SSA and SSEA, 725 (95%) were genetically dissimilar; 38 (5%) formed 19 sequence pairs. Inherent limitations of this study are that some cohorts may not represent the broader regional population and that studies were heterogeneous with respect to duration of infection prior to sampling. CONCLUSIONS: Most TDR strains in SSA and SSEA arose independently, suggesting that ARV regimens with a high genetic barrier to resistance combined with improved patient adherence may mitigate TDR increases by reducing the generation of new ARV-resistant strains. A small number of NNRTI-resistance mutations were responsible for most cases of high-level resistance, suggesting that inexpensive point-mutation assays to detect these mutations may be useful for pre-therapy screening in regions with high levels of TDR. In the context of a public health approach to ARV therapy, a reliable point-of-care genotypic resistance test could identify which patients should receive standard first-line therapy and which should receive a protease-inhibitor-containing regimen.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Sequência de Bases , Farmacorresistência Viral , Infecções por HIV/tratamento farmacológico , Transcriptase Reversa do HIV/genética , HIV-1/genética , Mutação , África , América , Fármacos Anti-HIV/farmacologia , Ásia , Europa (Continente) , Infecções por HIV/virologia , Transcriptase Reversa do HIV/antagonistas & inibidores , HIV-1/efeitos dos fármacos , Humanos , Epidemiologia Molecular , Filogenia
16.
ScientificWorldJournal ; 2015: 195972, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25811040

RESUMO

Pathogenic food-borne bacteria have been associated with severe morbidity and mortality in humans and animals. This study was aimed at determining the prevalence of Staphylococcus aureus, Salmonella spp., and Escherichia coli present in cattle and pigs slaughtered in selected abattoirs in Vhembe District and at determining the susceptibility of the isolates to antibiotics. A total of 176 swab samples (28 cattle and 16 pigs) of the rump, flank, brisket, and neck of the animals were analyzed using standard microbiological methods. E. coli isolates were genotyped to detect pathogenic strains. Of the 176 samples, 104 (67.5%) were positive for E. coli and 50 (32.5%) for S. aureus. There was no statistically significant difference (P > 0.05) in the isolation rate from the different animal parts or abattoirs. Overall, 14/104 (13.46%) of the E. coli isolates were pathogenic strains which included enteropathogenic E. coli (EPEC) (bfpA) 1.9%, enterotoxigenic E. coli (ETEC) (LT) 3.8%, and enteroaggregative E. coli (EAEC) (aaiC) 7.6%. E. coli isolates were resistant (100%) to vancomycin and bacitracin. S. aureus (100%) were resistant to oxacillin and nalidixic acid. The presence of resistant strains of these bacteria in food of animal origin could serve as important vehicles transmitting these bacteria to humans. This finding is of epidemiological significance.


Assuntos
Escherichia coli/isolamento & purificação , Microbiologia de Alimentos , Staphylococcus aureus/isolamento & purificação , Sus scrofa/microbiologia , Matadouros , Animais , Bovinos , Reservatórios de Doenças/microbiologia , Farmacorresistência Bacteriana , Escherichia coli/efeitos dos fármacos , Escherichia coli/patogenicidade , Microbiologia de Alimentos/estatística & dados numéricos , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase Multiplex , Prevalência , África do Sul/epidemiologia , Intoxicação Alimentar Estafilocócica/epidemiologia , Intoxicação Alimentar Estafilocócica/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/patogenicidade
17.
Artigo em Inglês | MEDLINE | ID: mdl-25427345

RESUMO

Intestinal parasitic organisms are common pathogens among HIV patients worldwide and have been known to cause severe and life-threatening diarrhea in such subjects. In the present study, the prevalence of Cryptosporidium spp and other intestinal parasites in stool samples from 151 HIV/AIDS patients attending a HIV treatment center in South Africa was determined using' standard parasitological methods, as well as molecular methods including PCR and quantitative PCR for confirmation of Cryptosporidium spp. In addition, the loop-mediated isothermal amplification (LAMP) method was evaluated for detection of Cryptosporidium spp in 24 stool samples. Standard parasitological methods indicated that Cryptospo- ridium spp (26.5%), Entamoeba spp (26.5%) and Giardia lamblia (13%) were the most common protozoan parasites, while Ascaris lumbricoides (8%), Schistosoma mansoni (6%) and Trichuris trichiura (4.6%) were the most commonly found helminths. PCR, quantitative PCR and LAMP methods identified Cryptosporidium spp in 28% (30/106), 35% (53/151) and 58% (14/24) of the stool samples, respectively. Multiple infections (34%) were commonly found in the study population. Females above 45 years had the highest Cryptosporidium prevalence (58%). Prevention measures must be implemented in order to curb the negative impact of Cryptosporidium-causing diarrhea among HIV/AIDS patients in this region as well as other parasitic infections identified in this study.


Assuntos
Cryptosporidium/isolamento & purificação , Infecções por HIV/epidemiologia , Helmintíase/epidemiologia , Enteropatias Parasitárias/epidemiologia , Infecções por Protozoários/epidemiologia , Síndrome da Imunodeficiência Adquirida/epidemiologia , Adolescente , Adulto , Instituições de Assistência Ambulatorial , Criança , Pré-Escolar , Coinfecção , Criptosporidiose/epidemiologia , Fezes/parasitologia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prevalência , África do Sul/epidemiologia , Adulto Jovem
19.
J Health Popul Nutr ; 31(1): 1-10, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23617199

RESUMO

Tuberculosis (TB) remains a deadly infectious disease affecting millions of people worldwide; 95% of TB cases, with 98% of death occur in developing countries. The situation in South Africa merits special attention. A total of 21,913 sputum specimens of suspected TB patients from three provinces of South Africa routinely submitted to the TB laboratory of Dr. George Mukhari (DGM) Hospital were assayed for Mycobacterium tuberculosis (MTB) growth and antibiotic susceptibility. The genetic diversity of 338 resistant strains were also studied. DNA isolated from the strains were restricted with Pvu II, transferred on to a nylon membrane and hybridized with a PCR-amplified horseradish peroxidase 245 bp IS6110 probe. Of the 338 resistant strains, 2.09% had less than 5 bands of IS6110, and 98% had 5 or more bands. Unique restriction fragment length polymorphism (RFLP) patterns were observed in 84.3% of the strains, showing their epidemiological independence, and 15.7% were grouped into 22 clusters. Thirty-two strains (61.5%) from the 52 that clustered were from Mpumalanga, 16/52 (30.8%) from Gauteng, and 4/52 (9.6%) from Limpopo province. Clustering was not associated with age. However, strains from male patients in Mpumalanga were more likely to be clustered than strains from male patients in Limpopo and/or Gauteng province. The minimum estimate for the proportion of resistant TB that was due to transmission is 9.06% (52-22 = 30/331). Our results indicate that transmission of drug-resistant strains may contribute substantially to the emergence of drug-resistant tuberculosis in South Africa.


Assuntos
Técnicas de Tipagem Bacteriana/métodos , Mycobacterium avium subsp. paratuberculosis/genética , Mycobacterium tuberculosis/genética , Polimorfismo de Fragmento de Restrição/genética , Tuberculose Resistente a Múltiplos Medicamentos/genética , Tuberculose Pulmonar/genética , Adolescente , Adulto , Distribuição por Idade , Idoso , Criança , Feminino , Variação Genética/genética , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Distribuição por Sexo , África do Sul , Escarro/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose Pulmonar/microbiologia , Adulto Jovem
20.
Am J Trop Med Hyg ; 109(2): 436-442, 2023 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-37536666

RESUMO

Early-life experiences of enteric infections and diarrheal illness are common in low-resource settings and are hypothesized to affect child development. However, longer-term associations of enteric infections with school-age cognitive outcomes are difficult to estimate due to lack of long-term studies. The objective of this study was to examine the relationship between enteropathogen exposure in the first 2 years of life with school-age cognitive skills in a cohort of children followed from birth until 6 to 8 years in low-resource settings in Brazil, Tanzania, and South Africa. The study included participants from three sites from the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health Study who were enrolled just after birth and followed for enteric infections, diarrheal illness, and cognitive development until 2 years of age. When the children were school-age, further data were collected on reasoning skills and semantic/phonemic fluency. We estimated associations between the burden of specific enteric pathogens and etiology-specific diarrhea from 0 to 2 years with cognitive test scores at 6 to 8 years using linear regression and adjusting for confounding variables. In this study, children who carried more enteric pathogens in the first 2 years of life showed overall decreases in school-age cognitive abilities, particularly children who carried protozoa, although this was not statistically significant in this sample. Socioeconomic factors such as maternal education and income were more closely associated with school-age cognitive abilities. Early-life enteric pathogens may have a small, lasting influence on school-age cognitive outcomes, although other socioeconomic factors likely contribute more significantly.


Assuntos
Diarreia , Classe Social , Criança , Humanos , Lactente , Estudos Longitudinais , Diarreia/epidemiologia , Desenvolvimento Infantil , Cognição
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