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1.
Lancet Microbe ; 2022 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-36057266

RESUMO

BACKGROUND: Assessment of disease severity associated with a novel pathogen or variant provides crucial information needed by public health agencies and governments to develop appropriate responses. The SARS-CoV-2 omicron variant of concern (VOC) spread rapidly through populations worldwide before robust epidemiological and laboratory data were available to investigate its relative severity. Here we develop a set of methods that make use of non-linked, aggregate data to promptly estimate the severity of a novel variant, compare its characteristics with those of previous VOCs, and inform data-driven public health responses. METHODS: Using daily population-level surveillance data from the National Institute for Communicable Diseases in South Africa (March 2, 2020, to Jan 28, 2022), we determined lag intervals most consistent with time from case ascertainment to hospital admission and within-hospital death through optimisation of the distance correlation coefficient in a time series analysis. We then used these intervals to estimate and compare age-stratified case-hospitalisation and case-fatality ratios across the four epidemic waves that South Africa has faced, each dominated by a different variant. FINDINGS: A total of 3 569 621 cases, 494 186 hospitalisations, and 99 954 deaths attributable to COVID-19 were included in the analyses. We found that lag intervals and disease severity were dependent on age and variant. At an aggregate level, fluctuations in cases were generally followed by a similar trend in hospitalisations within 7 days and deaths within 15 days. We noted a marked reduction in disease severity throughout the omicron period relative to previous waves (age-standardised case-fatality ratios were consistently reduced by >50%), most substantial for age strata with individuals 50 years or older. INTERPRETATION: This population-level time series analysis method, which calculates an optimal lag interval that is then used to inform the numerator of severity metrics including the case-hospitalisation and case-fatality ratio, provides useful and timely estimates of the relative effects of novel SARS-CoV-2 VOCs, especially for application in settings where resources are limited. FUNDING: National Institute for Communicable Diseases of South Africa, South African National Government.

2.
IJID Reg ; 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36065332

RESUMO

Objectives: This study describes characteristics of admitted HCWs reported to the DATCOV surveillance system and factors associated with in-hospital mortality in South African HCW. Methods: Data from 5 March 2020 to 30 April 2021 were obtained from DATCOV, a national hospital surveillance monitoring COVID-19 admissions in South Africa. Characteristics of HCWs were compared to non-HCWs. Furthermore, a logistic regression model was used to assess factors associated with in-hospital mortality among HCWs. Results: There were a total of 169,678 confirmed COVID-19 admissions, of which 6,364 (3.8%) were HCWs. HCW admissions were high in wave 1 (48.6%; n=3,095) than in wave 2 (32.0%; n=2,036). Admitted HCWs were less likely to be male (28.2%; n=1,791) [(aOR 0.3; 95% CI (0.3-0.4)], in the age group 50-59 (33.1%; n=2,103) [(aOR 1.4; 95%CI (1.1-1.8)], accessing private health sectors (63.3%; n=4,030) [(aOR 1.3; 95%CI (1.1-1.5)]. Age, comorbidities, race, wave, province and sector were significant risk factors for COVID-19 related mortality. Conclusion: The trends in cases show a decline in HCW admissions in wave 2 compared to wave 1. Acquired SARS-COV-2 immunity from prior infection may be a reason for reduced admissions and mortality of HCWs despite the more transmissible and more severe Beta variant in wave 2.

3.
Lancet Infect Dis ; 2022 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-35952703

RESUMO

Respiratory syncytial virus is the second most common cause of infant mortality and a major cause of morbidity and mortality in older adults (aged >60 years). Efforts to develop a respiratory syncytial virus vaccine or immunoprophylaxis remain highly active. 33 respiratory syncytial virus prevention candidates are in clinical development using six different approaches: recombinant vector, subunit, particle-based, live attenuated, chimeric, and nucleic acid vaccines; and monoclonal antibodies. Nine candidates are in phase 3 clinical trials. Understanding the epitopes targeted by highly neutralising antibodies has resulted in a shift from empirical to rational and structure-based vaccine and monoclonal antibody design. An extended half-life monoclonal antibody for all infants is likely to be within 1 year of regulatory approval (from August, 2022) for high-income countries. Live-attenuated vaccines are in development for older infants (aged >6 months). Subunit vaccines are in late-stage trials for pregnant women to protect infants, whereas vector, subunit, and nucleic acid approaches are being developed for older adults. Urgent next steps include ensuring access and affordability of a respiratory syncytial virus vaccine globally. This review gives an overview of respiratory syncytial virus vaccines and monoclonal antibodies in clinical development highlighting different target populations, antigens, and trial results.

4.
Clin Infect Dis ; 2022 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-35925613

RESUMO

BACKGROUND: In South Africa, 19% of the adult population are living with HIV (LWH). Few data on the influence of HIV on SARS-CoV-2 household transmission are available. METHODS: We performed a case-ascertained, prospective household transmission study of symptomatic index SARS-CoV-2 cases LWH and HIV-uninfected adults and their contacts in South Africa, October 2020 to September 2021. Households were followed up thrice weekly for 6 weeks to collect nasal swabs for SARS-CoV-2 testing. We estimated household cumulative infection risk (HCIR) and duration of SARS-CoV-2 positivity (at cycle threshold value <30 as proxy for high viral load). RESULTS: We recruited 131 index cases and 457 household contacts. HCIR was 59% (220/373); not differing by index HIV status (60% [51/85] in cases LWH vs 58% [163/279] in HIV-uninfected cases, OR 1.0, 95%CI 0.4-2.3). HCIR increased with index case age (35-59 years: aOR 3.4 95%CI 1.5-7.8 and ≥60 years: aOR 3.1, 95%CI 1.0-10.1) compared to 18-34 years, and contacts' age, 13-17 years (aOR 7.1, 95%CI 1.5-33.9) and 18-34 years (aOR 4.4, 95%CI 1.0-18.4) compared to <5 years. Mean positivity duration at high viral load was 7 days (range 2-17), with longer positivity in cases LWH (aHR 0.4, 95%CI 0.1-0.9). CONCLUSIONS: Index HIV status was not associated with higher HCIR, but cases LWH had longer positivity duration at high viral load. Adults aged >35 years were more likely to transmit, individuals aged 13-34 to acquire SARS-CoV-2 in the household. As HIV infection may increase transmission, health services must maintain HIV testing and antiretroviral therapy initiation.

5.
Int J Infect Dis ; 122: 1056-1066, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35934172

RESUMO

OBJECTIVES: Providing country-specific estimates of case fatality and sequelae from bacterial meningitis (BM) is important to evaluate and monitor progress toward the World Health Organization's roadmap to "defeating meningitis by 2030". METHODS: From 2016-2020, GERMS-SA conducted enhanced surveillance at 26 hospitals across South Africa. Episodes of laboratory-confirmed BM due to Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis were included. Risk factors for in-hospital death and sequelae at hospital discharge among survivors were analyzed. RESULTS: Of 12,717 invasive bacterial infections reported nationally, 39% (4980) were from enhanced surveillance sites, including 4159 pneumococcal, 640 H. influenzae, and 181 meningococcal infections. BM accounted for 32% (1319/4159) of pneumococcal, 21% (136/640) of H. influenzae, and 83% (151/181) of meningococcal invasive diseases. Clinical data were available for 91% (1455/1606) of BM: 26% (376/1455) were aged <5 years, 50% (726/1455) were female, and 62% (723/1171) with known HIV results, were HIV-infected. In-hospital case fatality was 37% (534/1455), and 24% (222/921) of survivors had adverse sequelae. Risk factors for death included altered mental status, HIV infection, and comorbidities. Risk factors for adverse sequelae included altered mental status and antimicrobial nonsusceptibility. CONCLUSION: BM in South Africa has a high case fatality, and adverse sequelae frequently occur among survivors. Those with comorbidities (including HIV) are at the highest risk.


Assuntos
Infecções por HIV , Meningites Bacterianas , Meningite Meningocócica , Meningite Pneumocócica , Neisseria meningitidis , Progressão da Doença , Feminino , Haemophilus influenzae , Mortalidade Hospitalar , Humanos , Lactente , Masculino , Meningites Bacterianas/complicações , Meningites Bacterianas/epidemiologia , Meningites Bacterianas/microbiologia , Meningite Meningocócica/epidemiologia , África do Sul/epidemiologia , Streptococcus pneumoniae
6.
Lancet Glob Health ; 10(9): e1247-e1256, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35961348

RESUMO

BACKGROUND: Post COVID-19 condition (PCC), as defined by WHO, refers to a wide range of new, returning, or ongoing health problems in people who have had COVID-19, and it represents a rapidly emerging public health priority. We aimed to establish how this developing condition has affected patients in South Africa and which population groups are at risk. METHODS: In this prospective cohort study, we used the DATCOV national hospital surveillance system to identify participants aged 18 years or older who had been hospitalised with laboratory-confirmed SARS-CoV-2 infection in South Africa. Participants underwent telephone follow-up assessment at 1 month and 3 months after hospital discharge. Participants were assessed using a standardised questionnaire for the evaluation of symptoms, functional status, health-related quality of life, and occupational status. We used negative binomial regression models to determine factors associated with PCC. FINDINGS: Of 241 159 COVID-19 admissions reported to DATCOV between Dec 1, 2020, and Aug 23, 2021, 8309 were randomly selected for enrolment. Of the 3094 patients that we were able to contact, 2410 (77·9%) consented to participate in the study at 1 month after discharge. Of these, 1873 (77·7%) were followed up at 3 months after hospital discharge. Participants had a median age of 52 years (IQR 41-62) and 960 (51·3%) were women. At 3 months of follow-up, 1249 (66·7%) of 1873 participants reported new or persistent COVID-19-related symptoms, compared with 1978 (82·1%) of 2410 at 1 month after hospital discharge. The most common symptoms reported at 3 months were fatigue (50·3%), shortness of breath (23·4%), confusion or lack of concentration (17·5%), headaches (13·8%), and problems seeing or blurred vision (10·1%). On multivariable analysis, the factors associated with persistent symptoms after acute COVID-19 were being female (adjusted incident rate ratio 1·20, 95% CI 1·04-1·38) and admission to an intensive care unit (1·17, 1·01-1·37). INTERPRETATION: Most participants in this cohort of individuals previously hospitalised with COVID-19 reported persistent symptoms 3 months after hospital discharge and a significant impact of PCC on their functional and occupational status. The large burden of PCC symptoms identified in this study emphasises the need for a national health strategy. This should include the development of clinical guidelines and training of health-care workers for identifying, assessing, and caring for patients affected by PCC; establishment of multidisciplinary health services; and provision of information and support to people who have PCC. FUNDING: Bill & Melinda Gates Foundation, UK Foreign, Commonwealth & Development Office, and Wellcome.


Assuntos
COVID-19 , SARS-CoV-2 , Adulto , COVID-19/epidemiologia , Estudos de Coortes , Feminino , Hospitalização , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Qualidade de Vida , África do Sul/epidemiologia
7.
medRxiv ; 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35982666

RESUMO

Objectives: We aimed to quantify transmission trends in South Africa during the first four waves of the COVID-19 pandemic using estimates of the time-varying reproduction number (R) and to compare the robustness of R estimates based on three different data sources and using data from public and private sector service providers. Methods: We estimated R from March 2020 through April 2022, nationally and by province, based on time series of rt-PCR-confirmed cases, hospitalizations, and hospital-associated deaths, using a method which models daily incidence as a weighted sum of past incidence. We also estimated R separately using public and private sector data. Results: Nationally, the maximum case-based R following the introduction of lockdown measures was 1.55 (CI: 1.43-1.66), 1.56 (CI: 1.47-1.64), 1.46 (CI: 1.38-1.53) and 3.33 (CI: 2.84-3.97) during the first (Wuhan-Hu), second (Beta), third (Delta), and fourth (Omicron) waves respectively. Estimates based on the three data sources (cases, hospitalisations, deaths) were generally similar during the first three waves but case-based estimates were higher during the fourth wave. Public and private sector R estimates were generally similar except during the initial lockdowns and in case-based estimates during the fourth wave. Discussion: Agreement between R estimates using different data sources during the first three waves suggests that data from any of these sources could be used in the early stages of a future pandemic. High R estimates for Omicron relative to earlier waves is interesting given a high level of exposure pre-Omicron. The agreement between public and private sector R estimates highlights the fact that clients of the public and private sectors did not experience two separate epidemics, except perhaps to a limited extent during the strictest lockdowns in the first wave.

8.
medRxiv ; 2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-36032973

RESUMO

South Africa was among the first countries to detect the SARS-CoV-2 Omicron variant. Propelled by increased transmissibility and immune escape properties, Omicron displaced other globally circulating variants within 3 months of its emergence. Due to limited testing, Omicron's attenuated clinical severity, and an increased risk of reinfection, the size of the Omicron BA.1 and BA.2 subvariants (BA.1/2) wave remains poorly understood in South Africa and in many other countries. Using South African data from urban and rural cohorts closely monitored since the beginning of the pandemic, we analyzed sequential serum samples collected before, during, and after the Omicron BA.1/2 wave to infer infection rates and monitor changes in the immune histories of participants over time. Omicron BA.1/2 infection attack rates reached 65% (95% CI, 60% - 69%) in the rural cohort and 58% (95% CI, 61% - 74%) in the urban cohort, with repeat infections and vaccine breakthroughs accounting for >60% of all infections at both sites. Combined with previously collected data on pre-Omicron variant infections within the same cohorts, we identified 14 distinct categories of SARS-CoV-2 antigen exposure histories in the aftermath of the Omicron BA.1/2 wave, indicating a particularly fragmented immunologic landscape. Few individuals (<6%) remained naïve to SARS-CoV-2 and no exposure history category represented over 25% of the population at either cohort site. Further, cohort participants were more than twice as likely to get infected during the Omicron BA.1/2 wave, compared to the Delta wave. Prior infection with the ancestral strain (with D614G mutation), Beta, and Delta variants provided 13% (95% CI, -21% - 37%), 34% (95% CI, 17% - 48%), and 51% (95% CI, 39% - 60%) protection against Omicron BA.1/2 infection, respectively. Hybrid immunity (prior infection and vaccination) and repeated prior infections (without vaccination) reduced the risks of Omicron BA.1/2 infection by 60% (95% CI, 42% - 72%) and 85% (95% CI, 76% - 92%) respectively. Reinfections and vaccine breakthroughs had 41% (95% CI, 26% - 53%) lower risk of onward transmission than primary infections. Our study sheds light on a rapidly shifting landscape of population immunity, along with the changing characteristics of SARS-CoV-2, and how these factors interact to shape the success of emerging variants. Our findings are especially relevant to populations similar to South Africa with low SARS-CoV-2 vaccine coverage and a dominant contribution of immunity from prior infection. Looking forward, the study provides context for anticipating the long-term circulation of SARS-CoV-2 in populations no longer naïve to the virus.

9.
medRxiv ; 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35794899

RESUMO

Objective: We aimed to compare clinical severity of Omicron BA.4/BA.5 infection with BA.1 and earlier variant infections among laboratory-confirmed SARS-CoV-2 cases in the Western Cape, South Africa, using timing of infection to infer the lineage/variant causing infection. Methods: We included public sector patients aged ≥20 years with laboratory-confirmed COVID-19 between 1-21 May 2022 (BA.4/BA.5 wave) and equivalent prior wave periods. We compared the risk between waves of (i) death and (ii) severe hospitalization/death (all within 21 days of diagnosis) using Cox regression adjusted for demographics, comorbidities, admission pressure, vaccination and prior infection. Results: Among 3,793 patients from the BA.4/BA.5 wave and 190,836 patients from previous waves the risk of severe hospitalization/death was similar in the BA.4/BA.5 and BA.1 waves (adjusted hazard ratio [aHR] 1.12; 95% confidence interval [CI] 0.93; 1.34). Both Omicron waves had lower risk of severe outcomes than previous waves. Prior infection (aHR 0.29, 95% CI 0.24; 0.36) and vaccination (aHR 0.17; 95% CI 0.07; 0.40 for boosted vs. no vaccine) were protective. Conclusion: Disease severity was similar amongst diagnosed COVID-19 cases in the BA.4/BA.5 and BA.1 periods in the context of growing immunity against SARS-CoV-2 due to prior infection and vaccination, both of which were strongly protective.

11.
Lancet Glob Health ; 10(8): e1170-e1178, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35839815

RESUMO

BACKGROUND: Few population-level estimates of invasive neonatal infections have been reported from sub-Saharan Africa. We estimated the national incidence risk, aetiology, and pathogen antimicrobial susceptibility for culture-confirmed neonatal bloodstream infections and meningitis in South Africa. METHODS: We conducted a cross-sectional study of neonates (<28 days of life) admitted to neonatal or paediatric wards of 256 public sector health facilities in South Africa during 2014-19. Diagnostic pathology records from Jan 1, 2014, to Dec 31, 2019, were extracted from a national pathology data warehouse. A case was defined as a neonate with at least one positive blood or cerebrospinal fluid culture during a 14-day period. Incidence risk was calculated using annual numbers of registered livebirths. Among the causative pathogens identified, we calculated the proportion of cases attributed to each of them, as well as the rates of antibiotic susceptibility of Gram-positive and Gram-negative bacteria. FINDINGS: Among 43 438 records of positive cultures, there were 37 631 incident cases of neonatal infection with at least one pathogen isolated. The overall incidence risk of culture-confirmed infections was 6·0 per 1000 livebirths (95% CI 6·0-6·1). The incidence risk of late-onset sepsis (days 3-27 of life) was 4·9 per 1000 livebirths (4·9-5·0) and that of early-onset sepsis (days 0-2 of life) was 1·1 per 1000 livebirths (1·1-1·1); risk ratio 4·4 (95% CI 4·3-4·5). The cause of infection differed by syndrome, timing of infection onset, facility, and province, although Klebsiella pneumoniae (26%), Acinetobacter baumannii (13%), and Staphylococcus aureus (12%) were the dominant pathogens overall. Gram-negative bacteria had declining susceptibility to most antibiotics over the study period. INTERPRETATION: We found a high incidence risk of late-onset sepsis with provincial variations, predominance of K pneumoniae, and declining antibiotic susceptibility among Gram-negative bacteria. This national surveillance in an upper-middle-income country provides a baseline burden of neonatal infections against which the impact of future clinical and public health interventions can be measured. FUNDING: Bill & Melinda Gates Foundation.


Assuntos
Doenças Transmissíveis , Meningite , Sepse , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Criança , Estudos Transversais , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Humanos , Recém-Nascido , Klebsiella pneumoniae , Meningite/epidemiologia , Sepse/microbiologia , África do Sul/epidemiologia
12.
Clin Infect Dis ; 2022 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-35717655

RESUMO

INTRODUCTION: Longitudinal pneumococcus colonization data in high HIV prevalence settings following pneumococcal conjugate vaccine introduction are limited. METHODS: In 327 randomly selected households, 1,684 individuals were enrolled and followed-up for 6-10 months during 2016-2018 from two communities. Nasopharyngeal swabs were collected twice-weekly and tested for pneumococcus using quantitative lytA real-time PCR. A Markov model was fitted to the data to define the start and end of an episode of colonization. We assessed factors associated with colonization using logistic regression. RESULTS: During the study period, 98% (1,655/1,684) of participants were colonized with pneumococcus at least once. Younger age (<5 years: adjusted odds ratio (aOR) 14.1, 95% confidence (CI) 1.8-111.3 and 5-24 years: aOR 4.8, 95% CI 1.9-11.9, compared to 25-44 years) and HIV-infection (aOR 10.1; 95% CI 1.3-77.1) were associated with increased odds of colonization. Children aged <5 years had fewer colonization episodes (median 9) than individuals ≥5 years (median 18; P < 0.001) but had a longer episode duration (<5 years: 35.5 days (interquartile range (IQR): 17-88) vs. ≥5 years: 5.5 days (4-12)). High pneumococcal loads were associated with age (<1 year: aOR 25.4, 95% CI 7.4-87.6; 1-4 years: aOR 13.5, 95% CI 8.3-22.9; 5-14 years: aOR 3.1, 95% CI 2.1-4.4 vs. 45-65 year olds) and HIV infection (aOR 1.7; 95% CI 1.2-2.4). CONCLUSIONS: We observed high levels of pneumococcus colonization across all age groups. Children and people living with HIV were more likely to be colonized and had higher pneumococcal loads. Carriage duration decreased with age highlighting that children remain important in pneumococcal transmission.

13.
Int J Infect Dis ; 122: 389-397, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35700877

RESUMO

OBJECTIVES: We describe the use of a multipathogen platform, TaqMan array card (TAC) real-time polymerase chain reaction, for the detection of pathogens in patients hospitalized with severe respiratory illness (SRI). METHODS: Prospective hospital-based syndromic surveillance for acute and chronic SRI was carried out at two sentinel sites in South Africa between January and December 2017. We tested respiratory specimens for 21 respiratory pathogens and blood samples for nine bacteria using TAC. Pathogen detection was compared by age group and HIV status using the chi-square test. RESULTS: During 2017, 956 patients of all ages were enrolled in the SRI surveillance, and of these, 637 (67%) patients were included in this study (637 blood, 487 naso- and oro-pharyngeal swabs, and 411 sputum specimens tested). At least one pathogen was detected in 83% (527/637) of patients. Common pathogens detected included Haemophilus influenzae (225/637; 35%), Streptococcus pneumoniae (224/637; 35%), rhinovirus (144/637; 23%), Staphylococcus aureus (129/637; 20%), Klebseilla pneumoniae (85/637; 13%), Mycobacterium tuberculosis (75/637; 12%), and respiratory syncytial virus (57/637; 9%). Multiple pathogens (≥2) were codetected in 57% (364/637) of patients. CONCLUSION: Although the use of a multi-pathogen platform improved pathogen yield, pathogen co-detections were common and would need clinical assessment for usefulness in individual-level treatment and management decisions.


Assuntos
Pneumonia , Infecções Respiratórias , Hospitalização , Humanos , Patologia Molecular , Pneumonia/diagnóstico , Estudos Prospectivos , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , África do Sul/epidemiologia
14.
Lancet Glob Health ; 10(7): e961-e969, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35597249

RESUMO

BACKGROUND: Up to the end of January, 2022, South Africa has had four recognisable COVID-19 pandemic waves, each predominantly dominated by one variant of concern: the ancestral strain with an Asp614Gly mutation during the first wave, the beta variant (B.1.351) during the second wave, the delta variant (B.1.617.2) during the third wave, and lastly, the omicron variant (B.1.1.529) during the fourth wave. We aimed to assess the clinical disease severity of patients admitted to hospital with SARS-CoV-2 infection during the omicron wave and compare the findings with those of the preceding three pandemic waves in South Africa. METHODS: We defined the start and end of each pandemic wave as the crossing of the threshold of weekly incidence of 30 laboratory-confirmed SARS-CoV-2 cases per 100 000 population. Hospital admission data were collected through an active national COVID-19-specific surveillance programme. We compared disease severity across waves by post-imputation random effect multivariable logistic regression models. Severe disease was defined as one or more of the following: acute respiratory distress, receipt of supplemental oxygen or mechanical ventilation, admission to intensive care, or death. FINDINGS: We analysed 335 219 laboratory-confirmed SARS-CoV-2 hospital admissions with a known outcome, constituting 10·4% of 3 216 179 cases recorded during the four waves. During the omicron wave, 52 038 (8·3%) of 629 617 cases were admitted to hospital, compared with 71 411 (12·9%) of 553 530 in the Asp614Gly wave, 91 843 (12·6%) of 726 772 in the beta wave, and 131 083 (10·0%) of 1 306 260 in the delta wave (p<0·0001). During the omicron wave, 15 421 (33·6%) of 45 927 patients admitted to hospital had severe disease, compared with 36 837 (52·3%) of 70 424 in the Asp614Gly wave, 57 247 (63·4%) of 90 310 in the beta wave, and 81 040 (63·0%) of 128 558 in the delta wave (p<0·0001). The in-hospital case-fatality ratio during the omicron wave was 10·7%, compared with 21·5% during the Asp614Gly wave, 28·8% during the beta wave, and 26·4% during the delta wave (p<0·0001). Compared with those admitted to hospital during the omicron wave, patients admitted during the other three waves had more severe clinical presentations (adjusted odds ratio 2·07 [95% CI 2·01-2·13] in the Asp614Gly wave, 3·59 [3·49-3·70] in the beta wave, and 3·47 [3·38-3·57] in the delta wave). INTERPRETATION: The trend of increasing cases and admissions across South Africa's first three waves shifted in the omicron wave, with a higher and quicker peak but fewer patients admitted to hospital, less clinically severe illness, and a lower case-fatality ratio compared with the preceding three waves. Omicron marked a change in the SARS-CoV-2 epidemic curve, clinical profile, and deaths in South Africa. Extrapolations to other populations should factor in differing vaccination and previous infection levels. FUNDING: National Institute for Communicable Diseases.


Assuntos
COVID-19 , Influenza Humana , COVID-19/epidemiologia , Hospitais , Humanos , Influenza Humana/epidemiologia , Pandemias , SARS-CoV-2 , África do Sul/epidemiologia
15.
BMC Public Health ; 22(1): 1035, 2022 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-35606732

RESUMO

BACKGROUND: Globally, long-term care facilities (LTCFs) experienced a large burden of deaths during the COVID-19 pandemic. The study aimed to describe the temporal trends as well as the characteristics and risk factors for mortality among residents and staff who tested positive for SARS-CoV-2 in selected LTCFs across South Africa. METHOD: We analysed data reported to the DATCOV sentinel surveillance system by 45 LTCFs. Outbreaks in LTCFs were defined as large if more than one-third of residents and staff had been infected or there were more than 20 epidemiologically linked cases. Multivariable logistic regression was used to assess risk factors for mortality amongst LTCF residents. RESULTS: A total of 2324 SARS-CoV-2 cases were reported from 5 March 2020 through 31 July 2021; 1504 (65%) were residents and 820 (35%) staff. Among LTCFs, 6 reported sporadic cases and 39 experienced outbreaks. Of those reporting outbreaks, 10 (26%) reported one and 29 (74%) reported more than one outbreak. There were 48 (66.7%) small outbreaks and 24 (33.3%) large outbreaks reported. There were 30 outbreaks reported in the first wave, 21 in the second wave and 15 in the third wave, with 6 outbreaks reporting between waves. There were 1259 cases during the first COVID-19 wave, 362 during the second wave, and 299 during the current third wave. The case fatality ratio was 9% (138/1504) among residents and 0.5% (4/820) among staff. On multivariable analysis, factors associated with SARS-CoV-2 mortality among LTCF residents were age 40-59 years, 60-79 years and ≥ 80 years compared to < 40 years and being a resident in a LTCF in Free State or Northern Cape compared to Western Cape. Compared to pre-wave 1, there was a decreased risk of mortality in wave 1, post-wave 1, wave 2, post-wave 2 and wave 3. CONCLUSION: The analysis of SARS-CoV-2 cases in sentinel LTCFs in South Africa points to an encouraging trend of decreasing numbers of outbreaks, cases and risk for mortality since the first wave. LTCFs are likely to have learnt from international experience and adopted national protocols, which include improved measures to limit transmission and administer early and appropriate clinical care.


Assuntos
COVID-19 , SARS-CoV-2 , Adulto , COVID-19/epidemiologia , Surtos de Doenças , Humanos , Assistência de Longa Duração , Pessoa de Meia-Idade , Pandemias , Instituições Residenciais , Estudos Retrospectivos , África do Sul/epidemiologia
16.
J Glob Health ; 12: 05013, 2022 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-35567586

RESUMO

Background: To date, COVID-19 vaccine coverage in the African region falls far too short of global goals. Increasing vaccination rates requires understanding barriers to vaccination so that effective interventions that sensitively and effectively address barriers to vaccination can be implemented. Methods: To assess COVID-19 vaccination levels and identify major barriers to vaccine uptake we conducted a population-based, cross-sectional survey among 1662 adults 18 and older from August 25 to October 29 2021 in the Agincourt Health and Socio-Demographic Surveillance System (AHDSS) area, Mpumalanga, South Africa. Results: Half of participants reported receiving a COVID-19 vaccine (50.4%) with 41.1% being fully vaccinated and 9.3% being partially vaccinated; 49.6% were unvaccinated. More women than men were vaccinated (55.5% vs 42.8%, P < 0.001), and older age groups were more likely to be vaccinated than younger age groups (P < 0.001). Among the unvaccinated, 69.0% planned to get vaccinated as soon as possible, while 14.7% reported definitely not wanting the vaccine. Major barriers to vaccination included lacking information on eligibility (12.3%) or where to get vaccinated (13.0%), concerns about side effects (12.5%), and inconvenient hours and locations for vaccination (11.0%). Confidence in the safety and efficacy of COVID-19 vaccines was higher among those vaccinated than unvaccinated (75.3% vs 51.2%, 75.8% vs 51.0%, both P < 0.001, respectively). Conclusions: Increasing vaccination in South Africa beyond current levels will require a concerted effort to address concerns around vaccine safety and increase confidence in vaccine efficacy. Clarifying eligibility and ensuring access to vaccines at times and places that are convenient to younger populations, men, and other vulnerable groups is necessary.


Assuntos
COVID-19 , Vacinas , Adulto , Idoso , COVID-19/epidemiologia , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Estudos Transversais , Feminino , Humanos , Masculino , SARS-CoV-2 , África do Sul/epidemiologia , Hesitação Vacinal
17.
Sci Transl Med ; 14(659): eabo7081, 2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-35638937

RESUMO

Understanding the build-up of immunity with successive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants and the epidemiological conditions that favor rapidly expanding epidemics will help facilitate future pandemic control. We analyzed high-resolution infection and serology data from two longitudinal household cohorts in South Africa to reveal high cumulative infection rates and durable cross-protective immunity conferred by prior infection in the pre-Omicron era. Building on the history of past exposures to different SARS-CoV-2 variants and vaccination in the cohort most representative of South Africa's high urbanization rate, we used mathematical models to explore the fitness advantage of the Omicron variant and its epidemic trajectory. Modeling suggests that the Omicron wave likely infected a large fraction (44 to 81%) of the population, leaving a complex landscape of population immunity primed and boosted with antigenically distinct variants. We project that future SARS-CoV-2 resurgences are likely under a range of scenarios of viral characteristics, population contacts, and residual cross-protection.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/epidemiologia , Humanos , Pandemias , África do Sul/epidemiologia
18.
Trop Med Int Health ; 27(6): 564-573, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35411997

RESUMO

OBJECTIVES: The objective was to compare COVID-19 outcomes in the Omicron-driven fourth wave with prior waves in the Western Cape, assess the contribution of undiagnosed prior infection to differences in outcomes in a context of high seroprevalence due to prior infection and determine whether protection against severe disease conferred by prior infection and/or vaccination was maintained. METHODS: In this cohort study, we included public sector patients aged ≥20 years with a laboratory-confirmed COVID-19 diagnosis between 14 November and 11 December 2021 (wave four) and equivalent prior wave periods. We compared the risk between waves of the following outcomes using Cox regression: death, severe hospitalisation or death and any hospitalisation or death (all ≤14 days after diagnosis) adjusted for age, sex, comorbidities, geography, vaccination and prior infection. RESULTS: We included 5144 patients from wave four and 11,609 from prior waves. The risk of all outcomes was lower in wave four compared to the Delta-driven wave three (adjusted hazard ratio (aHR) [95% confidence interval (CI)] for death 0.27 [0.19; 0.38]. Risk reduction was lower when adjusting for vaccination and prior diagnosed infection (aHR: 0.41, 95% CI: 0.29; 0.59) and reduced further when accounting for unascertained prior infections (aHR: 0.72). Vaccine protection was maintained in wave four (aHR for outcome of death: 0.24; 95% CI: 0.10; 0.58). CONCLUSIONS: In the Omicron-driven wave, severe COVID-19 outcomes were reduced mostly due to protection conferred by prior infection and/or vaccination, but intrinsically reduced virulence may account for a modest reduction in risk of severe hospitalisation or death compared to the Delta-driven wave.


Assuntos
COVID-19 , Técnicas de Laboratório Clínico , SARS-CoV-2 , Adulto , COVID-19/diagnóstico , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/virologia , Teste para COVID-19 , Vacinas contra COVID-19/administração & dosagem , Estudos de Coortes , Feminino , Humanos , Masculino , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Estudos Soroepidemiológicos , África do Sul/epidemiologia , Adulto Jovem
19.
Lancet ; 399(10330): 1141-1153, 2022 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-35305740

RESUMO

BACKGROUND: We aimed to assess the effectiveness of a single dose of the Ad26.COV2.S vaccine (Johnson & Johnson) in health-care workers in South Africa during two waves of the South African COVID-19 epidemic. METHODS: In the single-arm, open-label, phase 3B implementation Sisonke study, health-care workers aged 18 years and older were invited for vaccination at one of 122 vaccination sites nationally. Participants received a single dose of 5 × 1010 viral particles of the Ad26.COV2.S vaccine. Vaccinated participants were linked with their person-level data from one of two national medical insurance schemes (scheme A and scheme B) and matched for COVID-19 risk with an unvaccinated member of the general population. The primary outcome was vaccine effectiveness against severe COVID-19, defined as COVID-19-related admission to hospital, hospitalisation requiring critical or intensive care, or death, in health-care workers compared with the general population, ascertained 28 days or more after vaccination or matching, up to data cutoff. This study is registered with the South African National Clinical Trial Registry, DOH-27-022021-6844, ClinicalTrials.gov, NCT04838795, and the Pan African Clinical Trials Registry, PACTR202102855526180, and is closed to accrual. FINDINGS: Between Feb 17 and May 17, 2021, 477 102 health-care workers were enrolled and vaccinated, of whom 357 401 (74·9%) were female and 119 701 (25·1%) were male, with a median age of 42·0 years (33·0-51·0). 215 813 vaccinated individuals were matched with 215 813 unvaccinated individuals. As of data cutoff (July 17, 2021), vaccine effectiveness derived from the total matched cohort was 83% (95% CI 75-89) to prevent COVID-19-related deaths, 75% (69-82) to prevent COVID-19-related hospital admissions requiring critical or intensive care, and 67% (62-71) to prevent COVID-19-related hospitalisations. The vaccine effectiveness for all three outcomes were consistent across scheme A and scheme B. The vaccine effectiveness was maintained in older health-care workers and those with comorbidities including HIV infection. During the course of the study, the beta (B.1.351) and then the delta (B.1.617.2) SARS-CoV-2 variants of concerns were dominant, and vaccine effectiveness remained consistent (for scheme A plus B vaccine effectiveness against COVID-19-related hospital admission during beta wave was 62% [95% CI 42-76] and during delta wave was 67% [62-71], and vaccine effectiveness against COVID-19-related death during beta wave was 86% [57-100] and during delta wave was 82% [74-89]). INTERPRETATION: The single-dose Ad26.COV2.S vaccine shows effectiveness against severe COVID-19 disease and COVID-19-related death after vaccination, and against both beta and delta variants, providing real-world evidence for its use globally. FUNDING: National Treasury of South Africa, the National Department of Health, Solidarity Response Fund NPC, The Michael & Susan Dell Foundation, The Elma Vaccines and Immunization Foundation, and the Bill & Melinda Gates Foundation.


Assuntos
COVID-19 , Infecções por HIV , Vacinas , Ad26COVS1 , Adolescente , Adulto , Idoso , COVID-19/epidemiologia , COVID-19/prevenção & controle , Feminino , Humanos , Masculino , SARS-CoV-2 , África do Sul/epidemiologia
20.
Influenza Other Respir Viruses ; 16(5): 873-880, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35355414

RESUMO

BACKGROUND: Influenza accounts for a substantial number of deaths and hospitalisations annually in South Africa. To address this disease burden, the South African National Department of Health introduced a trivalent inactivated influenza vaccination programme in 2010. METHODS: We adapted and populated the WHO Seasonal Influenza Immunization Costing Tool (WHO SIICT) with country-specific data to estimate the cost of the influenza vaccination programme in South Africa. Data were obtained through key-informant interviews at different levels of the health system and through a review of existing secondary data sources. Costs were estimated from a public provider perspective and expressed in 2018 prices. We conducted scenario analyses to assess the impact of different levels of programme expansion and the use of quadrivalent vaccines on total programme costs. RESULTS: Total financial and economic costs were estimated at approximately USD 2.93 million and USD 7.91 million, respectively, while financial and economic cost per person immunised was estimated at USD 3.29 and USD 8.88, respectively. Expanding the programme by 5% and 10% increased economic cost per person immunised to USD 9.36 and USD 9.52 in the two scenarios, respectively. Finally, replacing trivalent inactivated influenza vaccine (TIV) with quadrivalent vaccine increased financial and economic costs to USD 4.89 and USD 10.48 per person immunised, respectively. CONCLUSION: We adapted the WHO SIICT and provide estimates of the total costs of the seasonal influenza vaccination programme in South Africa. These estimates provide a basis for planning future programme expansion and may serve as inputs for cost-effectiveness analyses of seasonal influenza vaccination programmes.


Assuntos
Vacinas contra Influenza , Influenza Humana , Análise Custo-Benefício , Humanos , Influenza Humana/prevenção & controle , Estações do Ano , África do Sul , Vacinação
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