Therapeutic response to four artemisinin-based combination therapies in Angola, 2021.

Monitoring antimalarial efficacy is important to detect the emergence of parasite drug resistance. Angola conducts in vivo therapeutic efficacy studies (TESs) every 2 years in its fixed sentinel sites in Benguela, Lunda Sul, and Zaire provinces. Children with uncomplicated Plasmodium falciparum malaria were treated with artemether-lumefantrine (AL), artesunate-amodiaquine (ASAQ), dihydroartemisinin-piperaquine (DP), or artesunate-pyronaridine (ASPY) and followed for 28 (AL and ASAQ) or 42 days (DP and ASPY) to assess clinical and parasitological response to treatment. Two drugs were sequentially assessed in each site in February-July 2021. The primary indicator was the Kaplan-Meier estimate of the PCR-corrected efficacy at the end of the follow-up period. A total of 622 patients were enrolled in the study and 590 (95%) participants reached a study endpoint. By day 3, ≥98% of participants were slide-negative in all study sites and arms. After PCR correction, day 28 AL efficacy was 88.0% (95% CI: 82%-95%) in Zaire and 94.7% (95% CI: 90%-99%) in Lunda Sul. For ASAQ, day 28 efficacy was 92.0% (95% CI: 87%-98%) in Zaire and 100% in Lunda Sul. Corrected day 42 efficacy was 99.6% (95% CI: 99%-100%) for ASPY and 98.3% (95% CI: 96%-100%) for DP in Benguela. High day 3 clearance rates suggest no clinical evidence of artemisinin resistance. This was the fourth of five rounds of TES in Angola showing a corrected AL efficacy <90% in a site. For Zaire, AL has had an efficacy <90% in 2013, 2015, and 2021. ASAQ, DP, and ASPY are appropriate choices as artemisinin-based combination therapies in Angola.

Blood count changes in malaria patients according to blood groups (ABO/Rh) and sickle cell trait.

INTRODUCTION: Introduction: Malaria continues to be the leading cause of hospitalization and death in Angola, a country in sub- Saharan Africa. In 2023, in the first quarter, 2,744,682 cases were registered, and of these 2,673 patients died due to malaria disease. Previous studies have shown that the ABO blood group can affect the progression of malaria to severe conditions after P. falciparum infection, while the sickle cell gene offers relative protection. OBJECTIVE: We investigated changes in the blood count according to blood groups (ABO/Rh) and sickle cell trait in patients with malaria in Luanda, capital of Angola. METHODOLOGY: This was a longitudinal, prospective and observational study with 198 patients hospitalized for malaria. RESULTS: Of the 198 patients studied, 13(6.6%) were ABRh(+), 4(2.0%) were ARh(-), 49(24.7%) were ARh(+), 42(21, 2%) were BRh (+), 5(2.5%) were ORh(-) and 85(42.9%) were ORh(+). For sickle cell trait, 145(73.2%) were AA, 37(18.7%) were AS and 16(8.1%) were SS. No statistical relationship was observed between age group, sex, parasitemia, clinical picture, hematocrit, MCV, HCM, MCHC, leukocytes, NEUT, LINF and PTL values with blood groups (p<0.05), but there was a relationship between values of hemoglobin and ABO/Rh blood groups (p>0.05). There was no relationship between age, parasitemia, clinical condition, MCV, HCM and MCHC values, leukocytes, NEUT and LINF with sickle cell trait (p<0.05), but there was a relationship between sex, hemoglobin and PTL and sickle cell values. sickle cell trait (p>0.05). CONCLUSION: It is imperative to differentiate patients with malaria based on blood groups and sickle cell trait, taking into account mainly the blood count parameters that demonstrate that there are patients who, depending on blood group or sickle cell trait, may react weakly to malaria infection regardless of the degree of parasitemia and medical prognosis.

Molecular Markers of Sulfadoxine-Pyrimethamine Resistance in Samples from Children with Uncomplicated Plasmodium falciparum at Three Sites in Angola in 2019.

Sulfadoxine-pyrimethamine (SP) is used for prevention of malaria in pregnant women in Angola. We sequenced the Plasmodium falciparum dihydrofolate reductase (pfdhfr) and dihydropteroate synthase (pfdhps) genes, implicated in SP resistance, in samples collected during a 2019 study of artemisinin-based combination therapy efficacy in Benguela, Lunda Sul, and Zaire provinces. A total of 90 day 0 and day of failure samples were individually sequenced, while 508 day 0 samples from participants without recurrent parasitemia were pooled after DNA extraction into 61 pools. The N51I, C59R, and S108N pfdhfr mutations and A437G pfdhps mutations were present at high proportions in all provinces (weighted allele frequencies, 62% to 100%). The K540E pfdhps mutation was present at lower proportions (10% to 14%). The A581G pfdhps mutation was only observed in Zaire, at a 4.6% estimated prevalence. The I431V and A613S mutations were also only observed in Zaire, at a prevalence of 2.8% to 2.9%. The most common (27% to 66%) reconstructed haplotype in all three provinces was the canonical quadruple pfdhfr pfdhps mutant. The canonical quintuple mutant was absent in Lunda Sul and Benguela and present in 7.9% of samples in Zaire. A single canonical sextuple (2.6%) mutant was observed in Zaire Province. Proportions of the pfdhps K540E and A581G mutations were well below the World Health Organization thresholds for meaningful SP resistance (prevalence of 95% for K540E and 10% for A581G). Samples from therapeutic efficacy studies represent a convenient source of samples for monitoring SP resistance markers.

Coinfection between SARS-CoV-2 and vector-borne diseases in Luanda, Angola.

Co-epidemics happening simultaneously can generate a burden on healthcare systems. The co-occurrence of SARS-CoV-2 with vector-borne diseases (VBD), such as malaria and dengue in resource-limited settings represents an additional challenge to the healthcare systems. Herein, we assessed the coinfection rate between SARS-CoV-2 and VBD to highlight the need to carry out an accurate diagnosis and promote timely measures for these infections in Luanda, the capital city of Angola. This was a cross-sectional study conducted with 105 subjects tested for the SARS-CoV-2 and VBD with a rapid detection test in April 2021. The participants tested positive for SARS-CoV-2 (3.80%), malaria (13.3%), and dengue (27.6%). Low odds related to testing positivity to SARS-CoV-2 or VBD were observed in participants above or equal to 40 years (odds ratio [OR]: 0.60, p = 0.536), while higher odds were observed in male (OR: 1.44, p = 0.392) and urbanized areas (OR: 3.78, p = 0.223). The overall co-infection rate between SARS-CoV-2 and VBD was 11.4%. Our findings showed a coinfection between SARS-CoV-2 with malaria and dengue, which could indicate the need to integrate the screening for VBD in the SARS-CoV-2 testing algorithm and the adjustment of treatment protocols. Further studies are warranted to better elucidate the relationship between COVID-19 and VBD in Angola.

Malaria in Angola: recent progress, challenges and future opportunities using parasite demography studies.

Over the past two decades, a considerable expansion of malaria interventions has occurred at the national level in Angola, together with cross-border initiatives and regional efforts in southern Africa. Currently, Angola aims to consolidate malaria control and to accelerate the transition from control to pre-elimination, along with other country members of the Elimination 8 initiative. However, the tremendous heterogeneity in malaria prevalence among Angolan provinces, as well as internal population movements and migration across borders, represent major challenges for the Angolan National Malaria Control Programme. This review aims to contribute to the understanding of factors underlying the complex malaria situation in Angola and to encourage future research studies on transmission dynamics and population structure of Plasmodium falciparum, important areas to complement host epidemiological information and to help reenergize the goal of malaria elimination in the country.

Continued Low Efficacy of Artemether-Lumefantrine in Angola in 2019.

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.

Seroprevalence of anti-SARS-CoV-2 antibodies and risk factors among healthy blood donors in Luanda, Angola.

BACKGROUND: SARS-CoV-2 emerged in China and spread throughout the world due to its rapid transmission. The exposure rate in the healthy population is unknown, mainly in resource-limited countries. Herein, we estimated the seroprevalence of anti-SARS-CoV-2 antibodies and risk factors among blood donors in Luanda, the capital city of Angola. METHODS: This was a retrospective study conducted with 343 blood donors. Chi-square and logistic regression were calculated to predict the independent variable for SARS-CoV-2 infection and deemed significant when p < 0.05. RESULTS: Seroprevalence of anti-SARS-CoV-2 was 4.7%. Positivity rates varied to age groups (3.5-14.3%), gender (0-5%), area of residence (3.1-.6%), educational level (5.1-10.2%), occupation (4.4-7.7%), and the blood donor category (2.0-5.1%). Past and recent infections were detected in 3.2% and 1.5%, respectively. Blood donors under the age of 20 years (OR: 4.58, p = 0.241) and from non-urbanized areas (OR: 1.86, p = 0.293) presented a high risk related to infection. The infection was higher in blood group A and lower in blood group O. The risk of SARS-CoV-2 infection has increased from January 2020 (OR: 0.03, p = 0.001) to August 2020 (OR: 0.57, p = 0.426). CONCLUSIONS: We provide an estimate of the exposure of healthy blood donors in Luanda. Also, we detected anti-SARS-CoV-2 in January 2020, indicating that the SARS-CoV-2 could have been imported during the first month of 2020. Further studies should be performed to assess the exposure rate in different groups from Angola.

HIV, hepatitis B virus, hepatitis C virus, and syphilis among pregnant women attending antenatal care in Luanda, Angola: Seroprevalence and risk factors.

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.

An efficient depyrogenation method for recombinant bacterial outer membrane lipoproteins.

Bacterial outer membrane lipoproteins are anchored in the outer membrane lipid layer in close association with lipopolysaccharides (LPS) and with other hydrophobic membrane proteins, making their purification technically challenging. We have previously shown that a thorough delipidation of outer membrane preparations from the Escherichia coli expression host is an important step to eliminate contaminant proteins when purifying recombinant antigens expressed in fusion with the Pseudomonas aeruginosa OprI lipoprotein. Here we report the cloning and expression of three antigens in fusion with OprI (ovalbumin, eGFP and BbPDI) and our efforts to deal with the variable LPS contamination levels observed in different batches of purified lipoproteins. The use of polymyxin B columns or endotoxin removal polycationic magnetic beads for depyrogenation of purified lipoproteins resulted in high protein losses and the use of Triton X-114 or sodium deoxycholate during the course of affinity chromatography showed to be ineffective to reduce LPS contamination. Instead, performing a hot phenol/water LPS extraction from outer membrane preparations prior to metal affinity chromatography allowed the purification of the recombinant fusion lipoproteins with LPS contents below 0.02EU/µg of protein. The purified recombinant lipoproteins retain their capacity to stimulate bone marrow-derived dendritic cells allowing for the study of their immunomodulatory properties through TLR2/1. This is a simple and easy to scale up method that can also be considered for the purification of other outer membrane lipoproteins.

Effects of the COVID-19 Pandemic on Breastfeeding Initiation and Duration: A Retrospective Cohort Study.

INTRODUCTION AND OBJECTIVES: Several studies support the health benefits of breastfeeding for both the mother and the newborn. However, a significant number of mothers discontinue breastfeeding within the first six months of childbirth, with several factors influencing breastfeeding adherence. The purpose of this study is to assess the impact of the COVID-19 pandemic on the prevention of mother-to-newborn infection transmission, breastfeeding patterns and duration, and the incidence of other infections during the first year of life. METHODS: Data from a sample of 39 mothers who gave birth at the Hospital Pedro Hispano in Porto, Portugual, between March 2020 and November 2021 were collected and a telephone questionnaire was administered. Statistical analysis was conducted using R software, v. 4.2.1 (R Foundation for Statistical Computing, Vienna, Austria). RESULTS AND DISCUSSION: In terms of the impact of the COVID-19 norm 18/2020, which went into effect on March 30th, our research found that the type of feeding during hospitalization was significantly influenced by this norm (X2=10.30, p=0.006). We also confirmed that mothers who received home assistance breastfed for an extra 4.5 months (95% CI: 1-7.5) compared with mothers who did not receive such assistance. Regarding the effect of COVID-19 and breastfeeding on newborn health, our study found that if the total duration of breastfeeding is less than six months, an infection is approximately five times more likely (95% CI = 1.06- 29.56). CONCLUSION: Overall, the findings of this study indicate that the efforts implemented at Hospital Pedro Hispano to limit the effects of the COVID-19 pandemic had some effect on immediate breastfeeding patterns, but not on the total duration of breastfeeding or newborn health. Nonetheless, more continuous assistance at home would have been beneficial.

HIV-1 diversity and pre-treatment drug resistance in the era of integrase inhibitor among newly diagnosed ART-naïve adult patients in Luanda, Angola.

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.

Assessment of the yellow fever outbreak in Angola from December 2015 through December 2016: A retrospective study.

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.

Hidden haemosporidian infections in Ruffs (Philomachus pugnax) staging in Northwest Europe en route from Africa to Arctic Europe.

In their African freshwater wintering habitats, shorebirds show a high prevalence of blood parasites, whereas no parasites are detected elsewhere along the migration route. We looked at two genera of haemosporidian parasites, Haemoproteus and Plasmodium, in the long-distance migrating Ruff (Philomachus pugnax) along a geographical/seasonal gradient to verify the infection pattern and examine possible hidden organ infections at European staging areas. We amplified parasite DNA from blood of 53 healthy birds wintering in Mali, 53 samples of seven organ tissues (spleen, liver, kidneys, heart, lungs, brain, and pectoral muscle) from healthy individuals caught during spring migration, and 18 weak birds found sick in summer in The Netherlands. We confirm that Ruffs wintering in Africa carried blood infections and that some infections developed into hidden organ infections during spring migration. Moreover, sick birds either had new infections (in one juvenile) or relapses (in an adult harboring an African lineage). Our results suggest that some parasites develop latency. This strategy may be beneficial for the parasite as it may take control over reappearance in the blood to help further transmission.

Hypothalamic hamartoma: a cause of precocious puberty.

Hypothalamic hamartomas are uncommon congenital malformations that present as precocious puberty, gelastic seizures and/or psychiatric disorders. Characteristic changes in MRI scans lead to a diagnosis. Treatment may include surgery or gonadotropin-releasing hormone agonists (GnRHa) depending on clinical manifestations.Here, we describe a case of hypothalamic hamartoma diagnosed in a girl in middle childhood, who presented with early development of secondary sexual characteristics. Physical examination, hormonal study, bone age and pelvic ultrasound findings were consistent with those of precocious puberty. The investigation also included a brain MRI scan, which revealed a small nodule with regular limits in the left hypothalamic region/tuber cinereum. GnRHa treatment and neurosurgical follow-ups were initiated promptly. The patient showed a reversal of secondary sexual characteristics and stable hamartoma size. This case illustrates the importance of brain MRI scans as part of the assessment of suspected precocious puberty because clinical features do not identify patients with an underlying pathology.

Linear Immunoglobulin A Dermatosis: A Rare Case Illustrating Successful Treatment With Dapsone.

This is the case report of a previously healthy four-year-old girl with a history of upper airway infection that was treated with a ß-lactam antibiotic. She was seen in the emergency department one month later with vesiculobullous lesions with clear content that were isolated or grouped in rosettes. Direct immunofluorescence showed baseline linear positivity for immunoglobulin A (IgA) (+) and fibrinogen-positive bullous content with absent remaining immunosera expression. The observed results were compatible with linear IgA bullous dermatosis. After confirming the diagnosis and excluding glucose-6-phosphate dehydrogenase (G6PD) deficiency, dapsone was added to the initial treatment with systemic and topical corticosteroids. This case report is a reminder of the importance of a high index of clinical suspicion for this condition to reach a timely diagnosis.

A Challenging Case: Botulism in a Toddler.

Botulism is a life-threatening, rapidly progressive neuroparalytic disease caused by one of the most potent toxins known, botulinum toxin. It manifests as flaccid and symmetrical descending paralysis that can affect both cranial and peripheral nerves. The only specific treatment available is the administration of botulinum antitoxin. We present the case of a three-year-old boy who had gastrointestinal symptoms and had ingested garden soil/dust at a construction site before the onset of cranial nerve palsy, which manifested as dysphagia in swallowing liquid and solid food and bilateral progressive ptosis. Early suspicion of botulism and treatment with botulinum antitoxin resulted in complete neurologic recovery. This case highlights the importance of a careful history and neurologic examination to avoid misdiagnosis. Administration of botulinum antitoxin should not be delayed until the diagnosis is confirmed and clinicians should be aware that this approach can be life-saving.

Congenital Infantile Myofibroma: The Importance of Molecular Diagnosis.

Infantile myofibromatosis is an uncommon soft tissue neoplasm that may present at birth or in early infancy. Although rare, this neoplasm is one of the most common benign fibrous tumors of infancy. Even though these tumors do not spread, they can compress or damage nearby organs. There is not an established management protocol, but it is advisable to maintain periodic clinical and imagological control until stability. Watchful waiting is an option to consider in the absence of problematic symptoms and visceral involvement. We report a case of solitary infantile myofibromatosis, without visceral involvement. It showed an initial rapid growth, raising concern among medical doctors and motivating soft tissue biopsy, always recommended as the clinical picture deviates from the classic presentation. Histology interpretation is often challenging, making genetics and clinical evaluation essential to exclude and prevent the misdiagnosing of more aggressive lesions.

Immune profile of healthcare professionals six months after vaccination or exposure to SARS-CoV-2 in Angola.

Background and Aims: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a public health concern. Until 2021, more than 2 million cumulative deaths were reported worldwide. Herein, we investigated the immune profile of healthcare professionals 6 months after vaccination or exposure to SARS-CoV-2 in Angola. Methods: This was a prospective study conducted with 1068 Angolan healthcare professionals between August and December 2021. Participants were screened for the presence of IgG and IgM against SARS-CoV-2. Results: About 9.6% and 98.2% of the participants had prior exposure to SARS-CoV-2 or vaccination against it, respectively. Participants aged between 20 and 40 years (11.2%), female (12.4%), with higher educational level (12.8%), from Luanda (60.3%), and nonhealthcare professionals (8.1%) were the most affected by the SARS-CoV-2. Gender, education, and local residence were related to SARS-CoV-2 exposure (p < 0.05). About 7.3% and 98% of the exposed population developed IgM and IgG after 3 months of exposure, respectively. The AstraZeneca vaccine was the most used, followed by the Jonhson & Johnson and Sputinik. Almost all (98%) participants vaccinated with AstraZeneca had immunity >3 months. Individuals who received only the first dose regardless of the type of vaccine had a higher immunity duration (>3 months) than those who received two doses. For individuals who received the Sputnik and Johnson, the average immunity was lower (<3 months), especially among those who were older (over 40 years old) and exposed to SARS-CoV-2. Conclusion: We observed a high adherence rate to vaccination and a long immunity duration. The immunity duration depended on the type of vaccine. Further studies on the immunity profile in the population exposed to SARS-CoV-2 must be carried out in the general population from Angola to assess antibody-waning periods.

Demographic characteristics and risk factors related to high blood pressure among healthy blood donors from Luanda, Angola: A retrospective study.

Background and Aims: Hypertension is a public health concern, mainly in resource-limited countries. We investigated the characteristics and risk factors related to high blood pressure in healthy blood donors from, Luanda, the capital city of Angola. Methods: This was a retrospective study that included 343 healthy donors from December 2019 to September 2020. Results: The mean age was 32 ± 9 years. Men represented 93% of the population. Mean systolic blood pressure (SBP) was 131 ± 12.3 mmHg (ranging from 100 to 160 mmHg) and diastolic blood pressure (DBP) was 80.1 ± 9.72 mmHg (from 56.0 to 100 mmHg). DBP was related to age and gender (p < 0.05). About 7.3% of the donors had high-pressure (>140/90 mmHg). Age between 20 and 40 years (odds ratio [OR]: 2.52, p = 0.043), women (OR: 1.87, p = 0.548), nonurbanized areas (OR: 0.39, p = 0.067), high educational level (OR: 0.76, p = 0.637), employed (OR: 0.49, p = 0.491), voluntary donors (OR: 0.87, p = 0.799), blood group B (OR: 2.06, p = 0.346), and Rh- (OR: 0.26, p = 0.104), were potentially related with high-pressure. The high-pressure cases increased from December 2019 (4%) to September 2020 (28%) (p = 0.019). Conclusion: We showed high pressure among the healthy blood donors population. Demographic characteristics, ABO/Rh blood group, and year period are features that should be considered in cardiovascular disease control strategies. Biological and nonbiological features related to blood pressure changes should be considered for further studies in the Angolan population.