41 research outputs found
HIV, hepatitis B virus, hepatitis C virus, and syphilis among pregnant women attending antenatal care in Luanda, Angola: seroprevalence and risk factors
No full textFundação para a Ciência e a Tecnologia, Grant/Award Number: SFRH/BD/135296/2017Infectious diseases during pregnancy remain a public health concern, especially in a resource-limited setting. The study aimed to determine the seroprevalence and determinants of HIV and co-infection with hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis among pregnant women attending antenatal care in Luanda, the capital city of Angola. A cross-sectional study was conducted with 1612 pregnant women screened for HIV during antenatal care. HIV-reactive were also screened for HBV, HCV, and syphilis using immunoassay kits. A logistic regression model, adjusted odds ratios (AOR) and their 95% confidence interval (CI) were calculated with a level of significance set at 5%. The overall seroprevalence of HIV was 2.6%. About 13% of HIV-positive pregnant women were coinfected. From which, 7.5% were reactive to HBV and 5% to syphilis. There was no reactivity to HCV. Pregnant women younger aged than 25 years were significantly protected from HIV-infection (AOR, 0.43 [95% CI, 0.20-0.91], P = .026). The co-infection was 1.3 times (AOR, 0.04-41.0) in younger aged than 25 years, 7.0 times (AOR, 0.50-99.2) to residents in urbanized areas, and 1.4 times (AOR, 0.10-20.9) in pregnant women with a high educational level. In conclusion, infectious diseases are a public health burden among pregnant women in Luanda. However, include an integrated antenatal screening mainly in urbanized areas is crucial to reduce the spread of infectious diseases in different communities of Angola.info:eu-repo/semantics/publishedVersio
Treatment of Plasmodium chabaudi Parasites with Curcumin in Combination with Antimalarial Drugs: Drug Interactions and Implications on the Ubiquitin/Proteasome System
No full textAntimalarial drug resistance remains a major obstacle in malaria control. Evidence from Southeast Asia shows that resistance to artemisinin combination therapy (ACT) is inevitable. Ethnopharmacological studies have confirmed the efficacy of curcumin against Plasmodium spp. Drug interaction assays between curcumin/piperine/chloroquine and curcumin/piperine/artemisinin combinations and the potential of drug treatment to interfere with the ubiquitin proteasome system (UPS) were analyzed. In vivo efficacy of curcumin was studied in BALB/c mice infected with Plasmodium chabaudi clones resistant to chloroquine and artemisinin, and drug interactions were analyzed by isobolograms. Subtherapeutic doses of curcumin, chloroquine, and artemisinin were administered to mice, and mRNA was collected following treatment for RT-PCR analysis of genes encoding deubiquitylating enzymes (DUBs). Curcumin was found be nontoxic in BALB/c mice. The combination of curcumin/chloroquine/piperine reduced parasitemia to 37% seven days after treatment versus the control group’s 65%, and an additive interaction was revealed. Curcumin/piperine/artemisinin combination did not show a favorable drug interaction in this murine model of malaria. Treatment of mice with subtherapeutic doses of the drugs resulted in a transient increase in genes encoding DUBs indicating UPS interference. If curcumin is to join the arsenal of available antimalarial drugs, future studies exploring suitable drug partners would be of interest
drug interactions and implications on the ubiquitin/proteasome system
No full textAntimalarial drug resistance remains a major obstacle in malaria control. Evidence from Southeast Asia shows that resistance to artemisinin combination therapy (ACT) is inevitable. Ethnopharmacological studies have confirmed the efficacy of curcumin against Plasmodium spp. Drug interaction assays between curcumin/piperine/chloroquine and curcumin/piperine/artemisinin combinations and the potential of drug treatment to interfere with the ubiquitin proteasome system (UPS) were analyzed. In vivo efficacy of curcumin was studied in BALB/c mice infected with Plasmodium chabaudi clones resistant to chloroquine and artemisinin, and drug interactions were analyzed by isobolograms. Subtherapeutic doses of curcumin, chloroquine, and artemisinin were administered to mice, and mRNA was collected following treatment for RT-PCR analysis of genes encoding deubiquitylating enzymes (DUBs). Curcumin was found be nontoxic in BALB/c mice. The combination of curcumin/chloroquine/piperine reduced parasitemia to 37% seven days after treatment versus the control group's 65%, and an additive interaction was revealed. Curcumin/piperine/artemisinin combination did not show a favorable drug interaction in this murine model of malaria. Treatment of mice with subtherapeutic doses of the drugs resulted in a transient increase in genes encoding DUBs indicating UPS interference. If curcumin is to join the arsenal of available antimalarial drugs, future studies exploring suitable drug partners would be of interest.publishersversionpublishe
NDVI and LST extraction of MODIS data under a GIS open source application - Rickettsia study case in Angola
No full textFevers of unknown origin can have different aetiologies. The overlapping symptomatology of rickettsial infection and other endemic diseases that cause fever leads to a misdiagnosis or under-diagnosis of spotted fever group of Rickettsia (SFGR).
To better understand the epidemiology of this vector-borne disease in Angola, a comprehensive seroprevalence study was conducted investigating the exposure to SFGR in a sample of 92 febrile, Malaria and Yellow Fever negative human plasma specimen, collected to the study of the national surveillance of febrile syndromes between 2016 and 2017, in Angola.
The seroprevalence of IgG antibodies against SFG Rickettsia in humans was calculated by gender, and aimag (province). All data were analyzed through a logistic regression. Spatial data sources included Normalized Differential Vegetation Index (NDVI) and Land Surface Temperature (LST) products by Moderate Resolution Imaging Spectroradiometer (MODIS).
The main objective of this work was the development of a GIS open source application to automatize the extraction of LST and NDVI products from MODIS images. The application was created as a simple graphic interface composed by two input fields (the text file with the coordinates of the sampling points (in sinusoidal coordinate system and the folder with the MODIS images), the field to define the buffer distance, and the output file. The application was tested considering MOD11A1 (LST product), MOD13Q1 and MYD13Q1 (NDVI product), free download from the USGS.
QGIS 2.18.17 was used for geospatial operations and Python language was employed for the development of the GIS open source application under QGIS software. The process includes the circumscription of the major clusters where human data were collected. Then, a convex hull (minimum convex bounding geometry) was created around each sampling site with a 10 km buffer zone to accommodate the mobility among the nomadic people being samples. Counts of seropositive and seronegative humans were calculated within each of these sampling clusters along with the mean, maximum, and minimum values of NDVI and LST, and percent area of each land cover class.
The application was tested in a set of 92 points in Angola and a buffer of 10 km considering the Universal transverse Mercator (UTM) Zone 33S projection (EPSG:32733) was applied for each point. The LST and NDVI statistical values were extracted for each sampling cluster.
Variations in ecological niches, abundance of vegetation and land surface temperature, for ticks and fleas between different provinces could be in part responsible for the geographic differences in seroprevalence observed with SFGR.A91F-E8B8-FA62 | Teresa Susana Letra MateusN/
DENGUE EM LUANDA, ANGOLA: DIAGNÓSTICO E ASPECTOS SÓCIO-DEMOGRÁFICOS 49 ANOS APÓS A DESCOBERTA DA CIRCULAÇÃO DO AGENTE ETIOLÓGICO
No full textIntrodução: Luanda é a capital de Angola, um país, que se situa no sudoeste africano. Os médicos, enfrentavam o problema do atendimento de inúmeros casos de síndromes febris de uma série de potenciais etiologias. O pacote de testes laboratorial, não incluía a avaliação de rotina da presença do vírus da dengue. A descoberta da circulação do vírus em Angola data de 1973, porém continuou sem registo até 2013. O objectivo do presente estudo foi, avaliar a consideração da probabilidade da infecção pelo vírus da dengue pela equipa de médicos, a frequência da infecção, o perfil sócio-demográfico, referente a idade, sexo, e os principais sintomas relacionados a infecção pela dengue, no período de Abril à Julho de 2022, para a produção de evidências científicas que possam mostrar a necessidade de colocar a dengue dentro da importância, no quadro nosológico de doenças transmissíveis em Angola. Métodos: Após assinatura de um documento de consentimento livre e esclarecido, foram analisadas clinicamente 140 pacientes adultos com síndromes febril e laboratorialmente as respectivas amostras de soro, colhidas em consultas, nas secções de Medicina Interna dos Hospitais dos Cajueiros e Américo Boavida, localizados em áreas sub-urbanas de Luanda. O diagnóstico laboratorial foi feito por testes seroimunológicos imunocromatográficos de diagnóstico rápido (TDRs), da marca SD Bioline, para a pesquisa de antigénios NS1, e paralelamente outro teste da presença de anticorpos IgM/IgG específicos contra o vírus da Dengue. Resultados: No total de 140 pacientes avaliados nas consultas, a dengue não foi considerada como hipótese diagnóstica, 35% (49/140) apresentaram infecções pelo vírus da dengue, detectada em indivíduos nas idades de 18 à 58 anos, tendo se constatado maior predominância de infecção em indivíduos mais jovens, de 18 à 28 anos, representando 40.81% (20/49) anos dos indivíduos, 57% e 43% foram do sexo masculino e feminino, respectivamente. Os sintomas mais frequentes, da dengue foram: febre (100% (49/49), dor retro-orbitrária (90% (44/49), cefaleias (100% (49/49), artralgias (100% (49/49), geralmente nos membros superiores, mialgias (41% (20/49). Conclusão: O vírus da dengue, pode ser o agente etiológico de inúmeros síndromes febris, que desafiam diariamente os médicos. O estudo epidemiológico da Dengue, envolvendo um maior é um necessidade prioritária para colocar a dengue na devida importância no quadro de doenças das doenças transmissíveis em Luanda, Angola
Evaluation of prevalence's of <it>pfdhfr </it>and <it>pfdhps </it>mutations in Angola
No full textAbstract Background Malaria is the major cause of morbidity and mortality in Angola. The most vulnerable groups to Plasmodium falciparum infection are pregnant women and children under five years of age. The use of an intermittent preventive treatment (IPT) with sulphadoxine/pyrimethamine (SP) in pregnant women was introduced in Angola in 2006 by the National Malaria Control Programme, and currently this strategy has been considered to be used for children malaria control. Considering the previous wide use of SP combination in Angola, together to the reported cases of SP treatment failure it is crucial the evaluation of the prevalence of five mutations in pfdhfr and pfdhps genes associated to P. falciparum resistance to SP before the introduction of S/P IPT in children. Methods The study was conducted in five provinces, with different transmission intensities: Huambo, Cabinda, Uíge, Kwanza Norte, and Malanje. The detection of the mutations in pfdhfr and pfdhps genes was carried out in 452 P. falciparum blood samples by PCR RFLP. Results For pfdhfr gene, 90,3% of the samples carried the mutation 51I, with 7.5% of mixed infections; 51% carried wild type allele 59C, with 29.2% mixed infections and; 99.1% of isolates harboured the mutant allele 108N. Concerning, pfdhps gene, 83,1% were mutant type 437G with 11% mixed infections , while 87% of the studied isolates were wild type for codon 540. Discussion This is the first representative epidemiological study of the whole Angola country on the prevalence of the genotypes associated with SP chemoresistance. A high frequency of individual mutations in both genes (51I and 108N in pfdhfr, and 437G in pfdhps) was found, besides a low prevalence of the quintuple mutation. Conclusion The data showed that the implementation IPT using SP in children needs to be reviewed.</p
High Detection Rate of Rotavirus Infection Among Children Admitted with Acute Gastroenteritis to Six Public Hospitals in Luanda Province After the Introduction of Rotarix® Vaccine: A Cross-Sectional Study
No full textRotavirus group A (RVA) is a major cause of pediatric acute gastroenteritis (AGE). Vaccination is an effective public health strategy and Angola implemented it in 2014. This hospital-based study aimed to estimate the prevalence of RVA infection and the severity of AGE in children under five years of age treated at six hospitals in Luanda Province. Between April 2021 and May 2022, 1251 fecal samples were screened by an immunochromatographic rapid test (SD Bioline). Data on socio-demographic profile, nutritional status, and clinical assessment were obtained. The association of RVA infection and AGE severity with possible risk factors was evaluated with a binary logistic regression model. Overall, the detection rate was 57.8% and girls tend to be more often infected than boys (55.2%). Infection was more common in the youngest group (1 to 6 months, 60.3%). Important sources of RVA infection were drinking water kept in tanks (57.9%) and private sanitary facilities with piped water (61%). Surprisingly, according to the Vesikari Scale score, the most severe symptoms were observed in children vaccinated with two doses (80.7%). RVA prevalence remains high despite vaccination, and further studies should address the association between infection sources and disease severity, as well as the causes underlying vaccine (un)effectiveness
Emerg Infect Dis
No full textWe used portable genome sequencing to investigate reported dengue virus transmission in Angola. Our results show that autochthonous transmission of dengue serotype 2 (cosmopolitan genotype) occurred in January 2018
<it>Plasmodium chabaudi chabaudi </it>malaria parasites can develop stable resistance to atovaquone with a mutation in the cytochrome b gene
No full textAbstract Background Plasmodium falciparum, has developed resistance to many of the drugs in use. The recommended treatment policy is now to use drug combinations. The atovaquone-proguanil (AP) drug combination, is one of the treatment and prophylaxis options. Atovaquone (ATQ) exerts its action by inhibiting plasmodial mitochondria electron transport at the level of the cytochrome bc1 complex. Plasmodium falciparum in vitro resistance to ATQ has been associated with specific point mutations in the region spanning codons 271-284 of the cytochrome b gene. ATQ -resistant Plasmodium yoelii and Plasmodium berghei lines have been obtained and resistant lines have amino acid mutations in their CYT b protein sequences. Plasmodium chabaudi model for studying drug-responses and drug-resistance selection is a very useful rodent malaria model but no ATQ resistant parasites have been reported so far. The aim of this study was to determine the ATQ sensitivity of the P. chabaudi clones, to select a resistant parasite line and to perform genotypic characterization of the cytb gene of these clones. Methods To select for ATQ resistance, Plasmodium. chabaudi chabaudi clones were exposed to gradually increasing concentrations of ATQ during several consecutive passages in mice. Plasmodium chabaudi cytb gene was amplified and sequenced. Results ATQ resistance was selected from the clone AS-3CQ. In order to confirm whether an heritable genetic mutation underlies the response of AS-ATQ to ATQ, the stability of the drug resistance phenotype in this clone was evaluated by measuring drug responses after (i) multiple blood passages in the absence of the drug, (ii) freeze/thawing of parasites in liquid nitrogen and (iii) transmission through a mosquito host, Anopheles stephensi. ATQ resistance phenotype of the drug-selected parasite clone kept unaltered. Therefore, ATQ resistance in clone AS-ATQ is genetically encoded. The Minimum Curative Dose of AS-ATQ showed a six-fold increase in MCD to ATQ relative to AS-3CQ. Conclusions A mutation was found on the P. chabaudi cytb gene from the AS-ATQ sample a substitution at the residue Tyr268 for an Asn, this mutation is homologous to the one found in P. falciparum isolates resistant to ATQ.</p
