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Biennial therapeutic efficacy monitoring is a crucial activity for ensuring the efficacy of currently used artemisinin-based combination therapy in Angola. Children with acute uncomplicated Plasmodium falciparum infection in sentinel sites in the Benguela, Zaire, and Lunda Sul Provinces were treated with artemether-lumefantrine (AL) or artesunate-amodiaquine (ASAQ) and monitored for 28 days to assess clinical and parasitological responses. Molecular correction was performed using seven microsatellite markers. Samples from treatment failures were genotyped for the pfk13, pfcrt, and pfmdr1 genes. Day 3 clearance rates were ≥95% in all arms. Uncorrected day 28 Kaplan-Meier efficacy estimates ranged from 84.2 to 90.1% for the AL arms and 84.7 to 100% for the ASAQ arms. Corrected day 28 estimates were 87.6% (95% confidence interval [CI], 81 to 95%) for the AL arm in Lunda Sul, 92.2% (95% CI, 87 to 98%) for AL in Zaire, 95.6% (95% CI, 91 to 100%) for ASAQ in Zaire, 98.4% (95% CI, 96 to 100%) for AL in Benguela, and 100% for ASAQ in Benguela and Lunda Sul. All 103 analyzed samples had wild-type pfk13 sequences. The 76T pfcrt allele was found in most (92%; 11/12) ASAQ late-failure samples but in only 16% (4/25) of AL failure samples. The N86 pfmdr1 allele was found in 97% (34/35) of treatment failures. The AL efficacy in Lunda Sul was below the 90% World Health Organization threshold, the third time in four rounds that this threshold was crossed for an AL arm in Angola. In contrast, the observed ASAQ efficacy has not been below 95% to date in Angola, including this latest round.
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Antimaláricos , Malária Falciparum , Amodiaquina/uso terapêutico , Angola , Antimaláricos/uso terapêutico , Artemeter/uso terapêutico , Combinação Arteméter e Lumefantrina , Criança , República Democrática do Congo , Combinação de Medicamentos , Etanolaminas/uso terapêutico , Humanos , Lactente , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/genéticaRESUMO
Infectious 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 the 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.
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We 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.
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Vírus da Dengue/genética , Dengue/epidemiologia , Dengue/virologia , Angola/epidemiologia , Evolução Molecular , Feminino , Genoma Viral , Humanos , Masculino , Técnicas de Diagnóstico Molecular , SorotipagemRESUMO
Background: Hepatitis B virus (HBV) remains a public health concern. Blood donors screened for HBV surface antigen (HBsAg) along with aspartate transaminase (AST)/alanine aminotransferase (ALT) could play a key in providing safe blood products. We investigated the features related to HBV infection among rejected blood donors in Luanda, Angola. Methods: This was a cross-sectional study conducted with 164 rejected donors. Donors were screened for HBsAg from March to May 2022. Overall, 63.4% tested positive for HBV. Results: The mean age of the HBV-positive (29.2 ± 8.02) was lower than the HBV-negative (33.9 ± 10.0) (p < 0.001). Donors between 20 and 40 years (odds ratio [OR]: 2.34, p = 0.045), females (OR: 1.40, p = 0.516), residents in urbanized areas (OR: 1.23, p = 0.530), low educational (OR: 1.54, p = 0.458), unemployed (OR: 1.65, p = 0.271), and unmarried (OR:1.41, p = 0.616) might be likely to contract HBV. AST/ALT ratio was higher in HBV-infected (2.07 ± 1.42) than in HBV-uninfected (1.90 ± 1.14). About 20% of HBV-positive were classified as having acute liver disease, while 80% with chronic liver disease, based on AST/ALT ratio. Age ranged from 20 to 40 years (OR: 1.97, p = 0.305), females (OR: 1.61, p = 0.557), donors from non-urbanized (OR: 1.69, p = 0.557), a low educational (OR: 1.64, p = 0.571), and unemployed donors (OR: 1.81, p = 0.289) were likely to develop chronic liver disease. Conclusions: Our findings indicated the failure of viral hepatitis control measures. Authorities should consider including HBV nucleic acid testing to ensure early identification of HBV in Angola.
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Background and Aims: The acute tropical infectious disease known as yellow fever (YF) is caused by an arbovirus and is characterized by fever, jaundice, hemorrhage, headache, muscle pain, nausea, vomiting, and fatigue. Angola experienced a yellow fever virus (YFV) outbreak that was documented in December 2015. However, little is known about the outcome of this outbreak. We aimed to demonstrate epidemic features and lessons learned during the YF epidemic in Angola. Methods: A total of 4618 blood samples from suspected YF cases were sent to the Instituto Nacional de Investigação em Saúde (INIS), a national referral and public health laboratory, between December 5, 2015, and December 23, 2016. Sample analyses were conducted using enzyme-linked immunosorbent assay (ELISA) and reverse transcription polymerase chain reaction (RT-PCR) assays. Blood samples were sent from 16 out of the 18 provinces of Angola. Results: We detected 884 (19.1%) cases that were positive for ELISA, which were confirmed by RT-PCR assay. Considering the positive cases, the incidence among male patients was around three times higher (n = 223; 10.9%) than in female patients (n = 59; 2.6%) in the 20-29 age group, followed by the age group 10-19 with n = 211 (6.8%) in males versus n = 108 (3.3%) in females; and the age group 30-39 had n = 68 (4.8%) in males versus n = 28 (1.8%) in females. The other groups had an incidence below 3.0%. The case fatality ratio for YF was in young adults in the age group 20-29 with n = 39 cases, followed by the age group 10-19 with n = 16 cases, and finally the age group 0-9 with n = 13 cases. The other age groups had several deaths by YF below 10 cases. Conclusions: This study demonstrates features of the YF epidemic that occurred in Angola. Also, it demonstrates that YF causes deaths in young people but is preventable by high vaccine coverage. Thus, public health laboratory surveillance must be strengthened to reduce the possibility of emerging and re-emerging human infections.
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The surveillance of drug resistance in the HIV-1 naïve population remains critical to optimizing the effectiveness of antiretroviral therapy (ART), mainly in the era of integrase strand transfer inhibitor (INSTI) regimens. Currently, there is no data regarding resistance to INSTI in Angola since Dolutegravir-DTG was included in the first-line ART regimen. Herein, we investigated the HIV-1 genetic diversity and pretreatment drug resistance (PDR) profile against nucleoside/tide reverse transcriptase inhibitors (NRTIs), non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), and INSTIs, using a next-generation sequencing (NGS) approach with MinION, established to track and survey DRMs in Angola. This was a cross-sectional study comprising 48 newly HIV-diagnosed patients from Luanda, Angola, screened between March 2022 and May 2023. PR, RT, and IN fragments were sequenced for drug resistance and molecular transmission cluster analysis. A total of 45 out of the 48 plasma samples were successfully sequenced. Of these, 10/45 (22.2%) presented PDR to PIs/NRTIs/NNRTIs. Major mutations for NRTIs (2.2%), NNRTIs (20%), PIs (2.2%), and accessory mutations against INSTIs (13.3%) were detected. No major mutations against INSTIs were detected. M41L (2%) and I85V (2%) mutations were detected for NRTI and PI, respectively. K103N (7%), Y181C (7%), and K101E (7%) mutations were frequently observed in NNRTI. The L74M (9%) accessory mutation was frequently observed in the INSTI class. HIV-1 pure subtypes C (33%), F1 (17%), G (15%), A1 (10%), H (6%), and D (4%), CRF01_AG (4%) were observed, while about 10% were recombinant strains. About 31% of detected HIV-1C sequences were in clusters, suggesting small-scale local transmission chains. No major mutations against integrase inhibitors were detected, supporting the continued use of INSTI in the country. Further studies assessing the HIV-1 epidemiology in the era of INSTI-based ART regimens are needed in Angola.
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Farmacorresistência Viral , Infecções por HIV , Inibidores de Integrase de HIV , HIV-1 , Humanos , HIV-1/genética , HIV-1/efeitos dos fármacos , Farmacorresistência Viral/genética , Angola/epidemiologia , Infecções por HIV/tratamento farmacológico , Infecções por HIV/virologia , Infecções por HIV/epidemiologia , Adulto , Masculino , Inibidores de Integrase de HIV/uso terapêutico , Inibidores de Integrase de HIV/farmacologia , Feminino , Estudos Transversais , Pessoa de Meia-Idade , Variação Genética , Adulto Jovem , Sequenciamento de Nucleotídeos em Larga Escala , Integrase de HIV/genéticaRESUMO
Background: In Angola, COVID-19 cases have been reported in all provinces, resulting in >105,000 cases and >1900 deaths. However, no detailed genomic surveillance into the introduction and spread of the SARS-CoV-2 virus has been conducted in Angola. We aimed to investigate the emergence and epidemic progression during the peak of the COVID-19 pandemic in Angola. Methods: We generated 1210 whole-genome SARS-CoV-2 sequences, contributing West African data to the global context, that were phylogenetically compared against global strains. Virus movement events were inferred using ancestral state reconstruction. Results: The epidemic in Angola was marked by four distinct waves of infection, dominated by 12 virus lineages, including VOCs, VOIs, and the VUM C.16, which was unique to South-Western Africa and circulated for an extended period within the region. Virus exchanges occurred between Angola and its neighboring countries, and strong links with Brazil and Portugal reflected the historical and cultural ties shared between these countries. The first case likely originated from southern Africa. Conclusion: A lack of a robust genome surveillance network and strong dependence on out-of-country sequencing limit real-time data generation to achieve timely disease outbreak responses, which remains of the utmost importance to mitigate future disease outbreaks in Angola.
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COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/epidemiologia , Angola/epidemiologia , Epidemiologia Molecular , PandemiasRESUMO
Artemisinin (ART) is recommended as the first-line drug for P. falciparum infections combined with a long-acting partner drug. The emergence of P. falciparum resistance to ART (ARTR) is a concern for malaria. The most feared threat remains the spread of ARTR from Southeast Asia to Africa or the independent emergence of ARTR in Africa, where malaria accounts for 93% of all malaria cases and 94% of deaths. To avoid this worst-case scenario, surveillance of Pfkelch13 mutations is essential. We investigated mutations of Pfkelch13 in 78 P. falciparum samples from Huambo, Angola. Most of the parasites had a wild-type Pfkelch13 allele. We identified one synonymous mutation (R471R) in 10 isolates and one non-synonymous mutation (A578S) in two samples. No Pfkelch13 validated or candidate ARTR mutants were identified. The finding suggests that there is little polymorphism in Pfkelch13 in Huambo. Since cases of late response to ART in Africa and the emergence of ARTR mutations in Rwanda and Uganda have been reported, efforts should be made toward continuous molecular surveillance of ARTR. Our study has some limitations. Since we analyzed P. falciparum parasites from a single health facility, the study may not be representative of all Angolan endemic areas.
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BACKGROUND: The transmission patterns and genetic diversity of dengue virus (DENV) circulating in Africa remain poorly understood. Circulation of the DENV serotype 1 (DENV1) in Angola was detected in 2013, while DENV serotype 2 (DENV2) was detected in 2018. Here, we report results from molecular and genomic investigations conducted at the Ministry of Health national reference laboratory (INIS) in Angola on suspected dengue cases detected between January 2017 and February 2019. METHODS: A total of 401 serum samples from dengue suspected cases were collected in 13 of the 18 provinces in Angola. Of those, 351 samples had complete data for demographic and epidemiological analysis, including age, gender, province, type of residence, clinical symptoms, as well as dates of onset of symptoms and sample collection. RNA was extracted from residual samples and tested for DENV-RNA using two distinct real time RT-PCR protocols. On-site whole genome nanopore sequencing was performed on RT-PCR+ samples. Bayesian coalescent models were used to estimate date and origin of outbreak emergence, as well as population growth rates. RESULTS: Molecular screening showed that 66 out of 351 (19%) suspected cases were DENV-RNA positive across 5 provinces in Angola. DENV RT-PCR+ cases were detected more frequently in urban sites compared to rural sites. Of the DENV RT-PCR+ cases most were collected within 6 days of symptom onset. 93% of infections were confirmed by serotype-specific RT-PCR as DENV2 and 1 case (1.4%) was confirmed as DENV1. Six CHIKV RT-PCR+ cases were also detected during the study period, including 1 co-infection of CHIKV with DENV1. Most cases (87%) were detected in Luanda during the rainy season between April and October. Symptoms associated with severe dengue were observed in 11 patients, including 2 with a fatal outcome. On-site nanopore genome sequencing followed by genetic analysis revealed an introduction of DENV2 Cosmopolitan genotype (also known as DENV2-II genotype) possibly from India in or around October 2015, at least 1 year before its detection in the country. Coalescent models suggest relatively moderately rapid epidemic growth rates and doubling times, and a moderate expansion of DENV2 in Angola during the studied period. CONCLUSION: This study describes genomic, epidemiological and demographic characteristic of predominately urban transmission of DENV2 in Angola. We also find co-circulation of DENV2 with DENV1 and CHIKV and report several RT-PCR confirmed severe dengue cases in the country. Increasing dengue awareness in healthcare professional, expanding the monitorization of arboviral epidemics across the country, identifying most common mosquito breeding sites in urban settings, implementing innovative vector control interventions and dengue vaccination campaigns could help to reduce vector presence and DENV transmission in Angola.
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Vírus da Dengue , Dengue , Dengue Grave , Angola/epidemiologia , Animais , Teorema de Bayes , Vírus da Dengue/genética , Surtos de Doenças , Genômica , Humanos , Mosquitos Vetores , Filogenia , RNA , Sorogrupo , Dengue Grave/epidemiologiaRESUMO
[This corrects the article DOI: 10.1371/journal.pone.0249249.].
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This study aimed to investigate the characteristics related to SARS-CoV-2 in Luanda, Angola. A total of 622 individuals were screened for SARS-CoV-2 from January to September 2020. Chi-square and logistic regression were used to identify the relationship between sociodemographic characteristics and SARS-CoV-2. Of the 622 tested, 14.3% tested positive. The infection rate was the same for both genders (14.3%). Individuals ≥40 years old, from non-urbanized areas, and healthcare professionals had a higher frequency of infection. The risk of infection was very high in individuals ≥60 years old (AOR: 23.3, 95% CI: 4.83-112), in women (AOR: 1.24, 95% CI: 0.76-2.04), in Luanda (AOR: 7.40, 95% CI: 1.64-33.4), and healthcare professionals (AOR: 1.27, 95% CI: 0.60-2.71), whereas a low risk was observed in individuals from urbanized areas (AOR: 0.44, 95% CI: 0.26-0.75). Our results suggest that Angolan authorities should implement a greater effort in non-urbanized areas and among healthcare professionals since when these individuals presented any indication for a COVID-19 test, such as fever/cough/myalgia, they were more likely to test positive for SARS-CoV-2 than having some other cause for symptoms.
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COVID-19/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Angola , COVID-19/patologia , COVID-19/virologia , Teste para COVID-19 , Criança , Pré-Escolar , Estudos Transversais , Demografia , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fatores de Risco , SARS-CoV-2/isolamento & purificação , Adulto JovemRESUMO
Monitoring genetic diversity and drug resistance mutations (DRMs) is critical for understanding HIV epidemiology. Here, we report HIV-1 genetic diversity and DRMs in blood samples from 42 HIV-positive pregnant women naive to antiretroviral therapy (ART), in Luanda. The samples were subjected to nested-PCR, followed by sequencing of HIV-1 pol gene, targeting the protease and reverse transcriptase fragments. HIV-1 diversity was analyzed using the REGA HIV-1 subtyping tool and DRMs were identified using the Calibrated Population Resistance tool. A total of 34 sequences were obtained. The data revealed wide HIV-1 subtypes heterogeneity, with subtype C (38%, 13/34) the most frequent, followed by the subtypes F1 (18%, 6/34), A1 (9%, 3/34), G (9%, 3/34), D (6%, 2/34) and H (3%, 1/34). In addition, recombinants strains were detected, with CRF02_AG (6%, 2/34) the most frequent, followed by CRF37_cpx, F1/C, A1/G and H/G, all with 3% (1/34). A total of 6/34 (18%) of the sequences presented DRMs. The non-nucleoside reverse transcriptase inhibitors presented 15% (5/34) of resistance. Moreover, 1/34 (3%) sequence presented resistance against both non-nucleoside reverse transcriptase inhibitors and nucleoside reverse transcriptase inhibitors, simultaneously. Despite the small sample size, our results suggest the need to update currently used ART regimens. Surveillance of HIV-1 subtypes and DRMs are necessary to understand HIV epidemiology and to guide modification of ART guidelines in Angola.
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Fármacos Anti-HIV/farmacologia , Farmacorresistência Viral , Infecções por HIV/diagnóstico , HIV-1/genética , Complicações Infecciosas na Gravidez/virologia , Produtos do Gene pol do Vírus da Imunodeficiência Humana/genética , Adolescente , Adulto , Angola , Estudos Transversais , Feminino , Variação Genética , Técnicas de Genotipagem , HIV-1/classificação , HIV-1/efeitos dos fármacos , Humanos , Filogenia , Vigilância da População , Gravidez , Tamanho da Amostra , Análise de Sequência de RNA/métodos , Adulto JovemRESUMO
BACKGROUND: Zika virus infections and suspected microcephaly cases have been reported in Angola since late 2016, but no data are available about the origins, epidemiology, and diversity of the virus. We aimed to investigate the emergence and circulation of Zika virus in Angola. METHODS: Diagnostic samples collected by the Angolan Ministry of Health as part of routine arboviral surveillance were tested by real-time reverse transcription PCR by the Instituto Nacional de Investigação em Saúde (Ministry of Health, Luanda, Angola). To identify further samples positive for Zika virus and appropriate for genomic sequencing, we also tested samples from a 2017 study of people with HIV in Luanda. Portable sequencing was used to generate Angolan Zika virus genome sequences from three people positive for Zika virus infection by real-time reverse transcription PCR, including one neonate with microcephaly. Genetic and mobility data were analysed to investigate the date of introduction and geographical origin of Zika virus in Angola. Brain CT and MRI, and serological assays were done on a child with microcephaly to confirm microcephaly and assess previous Zika virus infection. FINDINGS: Serum samples from 54 people with suspected acute Zika virus infection, 76 infants with suspected microcephaly, 24 mothers of infants with suspected microcephaly, 336 patients with suspected dengue virus or chikungunya virus infection, and 349 samples from the HIV study were tested by real-time reverse transcription PCR. Four cases identified between December, 2016, and June, 2017, tested positive for Zika virus. Analyses of viral genomic and human mobility data suggest that Zika virus was probably introduced to Angola from Brazil between July, 2015, and June, 2016. This introduction probably initiated local circulation of Zika virus in Angola that continued until at least June, 2017. The infant with microcephaly in whom CT and MRI were done had brain abnormalities consistent with congenital Zika syndrome and serological evidence for Zika virus infection. INTERPRETATION: Our analyses show that autochthonous transmission of the Asian lineage of Zika virus has taken place in Africa. Zika virus surveillance and surveillance of associated cases of microcephaly throughout the continent is crucial. FUNDING: Royal Society, Wellcome Trust, Global Challenges Research Fund (UK Research and Innovation), Africa Oxford, John Fell Fund, Oxford Martin School, European Research Council, Departamento de Ciência e Tecnologia/Ministério da Saúde/National Council for Scientific and Technological Development, and Ministério da Educação/Coordenação de Aperfeicoamento de Pessoal de Nível Superior.