Ethnically Disparate Disease Progression and Outcomes among Acute Rheumatic Fever Patients in New Zealand, 1989–2015

We investigated outcomes for patients born after 1983 and hospitalized with initial acute rheumatic fever (ARF) in New Zealand during 1989–2012. We linked ARF progression outcome data (recurrent hospitalization for ARF, hospitalization for rheumatic heart disease [RHD], and death from circulatory causes) for 1989–2015. Retrospective analysis identified initial RHD patients <40 years of age who were hospitalized during 2010–2015 and previously hospitalized for ARF. Most (86.4%) of the 2,182 initial ARF patients did not experience disease progression by the end of 2015. Progression probability after 26.8 years of theoretical follow-up was 24.0%; probability of death, 1.0%. Progression was more rapid and ≈2 times more likely for indigenous Māori or Pacific Islander patients. Of 435 initial RHD patients, 82.2% had not been previously hospitalized for ARF. This young cohort demonstrated low mortality rates but considerable illness, especially among underserved populations. A national patient register could help monitor, prevent, and reduce ARF progression.     

Acute rheumatic fever and rheumatic heart disease in the Kimberley: using hospitalisation data to find cases and describe trends

Objective: To describe the epidemiology of hospitalisations due to acute rheumatic fever (ARF) and rheumatic heart disease (RHD) in the Kimberley region of Western Australia (WA) and use these data to improve completeness of the WA RHD Register. Methods: Retrospective analysis of Kimberley regional hospitalisation data for hospitalisations coded as ARF/RHD from 01/07/2002 to 30/06/2012, with individual follow‐up of those not on the register. Annual age‐standardised hospitalisation rates were calculated to determine hospitalisation trend. Results: There were 250 admissions among 193 individuals. Of these, 53 individuals (27%) with confirmed or probable ARF/RHD were not on the register. Males were less likely to be on the register (62% versus 79% of females, p<0.01), as were those hospitalised with ARF without heart involvement (68% versus 87% of other ARF diagnoses, p<0.01). ARF/RHD hospitalisation rates decreased by 8.8% per year (p<0.001, rate ratio = 0.91, 95%CI 0.87–0.96). Conclusions and implications: Using hospitalisation data is an effective method of identifying cases of ARF/RHD not currently on the register. This process could be undertaken for initial case finding in areas with newly established registers, or as regular quality assurance in areas with established register‐based programs. Reasons for the observed decrease in hospitalisation rates remain unclear and warrant further investigation.     

Risk factors for respiratory syncytial virus bronchiolitis hospital admission in New Zealand

This study assessed risk factors for respiratory syncytial virus (RSV) hospitalization and disease severity in Wellington, New Zealand. During the southern hemisphere winter months of 2003--2005, 230 infants aged < 24 months hospitalized with bronchiolitis were recruited. RSV was indentified in 141 (61%) infants. Comparison with data from all live hospital births from the same region (2003--2005) revealed three independent risk factors for RSV hospitalization: birth between February and July [adjusted risk ratio (aRR) 1.62, 95% confidence interval (CI) 1.5-2.29], gestation <37 weeks (aRR 2.29, 95% CI 1.48-3.56) and Māori ethnicity (aRR 3.64, 95% CI 2.27-5.85), or Pacific ethnicity (aRR 3.60, 95% CI 2.14-6.06). The high risk for Māori and Pacific infants was only partially accounted for by other known risk factors. This work highlights the importance of RSV disease in indigenous and minority populations, and identifies the need for further research to develop public health measures that can reduce health disparities.     

Disparities in Hospitalizations Among HIV Positive Individuals for Native Hawaiians and Asians Compared to Whites in Hawai‘i

Hospitalizations of those living with HIV are expensive and often indicate failures in access to, or retention in, primary care. Higher rates of hospitalizations among individuals with HIV have been reported in some US ethnic minorities, yet little information is available for Native Hawaiians and Asian subgroups. All hospitalizations in Hawai‘i of individuals aged ≥13 years from December 2006–December 2010 were considered. Hospitalizations of individuals with HIV were identified using ICD-9 diagnosis codes of 042 and V08; 613 hospitalizations with an HIV diagnostic code were found. Using Hawaii State Department of Health 2010 data, estimated rates of hospitalizations among HIV positive individuals by race/ethnicity among the 2,600 Hawai‘i residents living with HIV were calculated along with estimated rate ratios (using Whites as the reference group). Multivariable adjusted estimated rate ratios (aRR) were calculated with negative binomial models, adjusting for age, sex, and payer type. Demographic and clinical differences among hospitalized patients with HIV were also compared by race/ethnicity. Native Hawaiians (aRR: 3.21; 95%CI: 2.11–4.88), Japanese (aRR: 2.27; 95%CI: 1.38–3.72), and Filipinos (aRR: 1.62; 95%CI: 1.01–2.59) living with HIV all had higher likelihood of a hospitalization compared to Whites, even when controlling for age, sex, and payer. Chinese did not vary significantly from Whites. Also of note, the average age of HIV positive individuals who were hospitalized varied significantly across groups (P-value < .001), with Native Hawaiians as the youngest (45 years), followed by Filipinos (47 years), Whites (49 years), Chinese (50 years) and Japanese (54 years). Disparities appear to exist in hospitalizations among HIV positive individuals for Native Hawaiians and Asian subgroups. Further research is warranted to investigate the reasons for these health disparities.     

Risk Factors of Rheumatic Heart Disease in Bangladesh: A Case-Control Study

Not all cases of rheumatic fever (RF) end up as rheumatic heart disease (RHD). The fact raises the possibility of existence of a subgroup with characteristics that prevent RF patients from developing the RHD. The present study aimed at exploring the risk factors among patients with RHD. The study assessed the risk of RHD among people both with and without RF. In total, 103 consecutive RHD patients were recruited as cases who reported to the National Centre for Control of Rheumatic Fever and Heart Disease, Dhaka, Bangladesh. Of 309 controls, 103 were RF patients selected from the same centre, and the remaining 206 controls were selected from Shaheed Suhrawardy Medical College Hospital, who got admitted for other non-cardiac ailments. RHD was confirmed by auscultation and colour Doppler echocardiography. RF was diagnosed based on the modified Jones criteria. An unadjusted odds ratio was generated for each variable, with 95% confidence interval (CI), and only significant factors were considered candidate for multivariate analysis. Three separate binary logistic regression models were generated to assess the risk factors of RF, risk factors of RHD compared to non-rheumatic control patients, and risk factors of RHD compared to control with RF. RF and RHD shared almost a similar set of risk factors in the population. In general, age over 19 years was found to be protective of RF; however, age of the majority (62.1%) of the RHD cases was over 19 years. Women [odds ratio (OR)=2.2, 95% CI 1.1-4.3], urban resident (OR=3.1, 95% CI 1.2–8.4), dwellers in brick-built house (OR=3.6, 95% CI 1.6-8.1), having >2 siblings (OR=3.1, 95% CI 1.5- 6.3), offspring of working mothers (OR=7.6, 95% CI 2.0-24.2), illiterate mother (OR=2.6, 95% CI 1.2-5.8), and those who did not brush after taking meals (OR=2.5, 95% CI 1.0-6.3) were more likely to develop RF. However, more than 5 members in a family showed a reduced risk of RF. RHD shared almost a similar set of factors in general. More than three people sharing a room also showed an increased risk of RHD (OR=1.9, 95% CI 1.0-3.4), in addition to the risk factors of RF. Multivariate model also assessed the factors that may perpetuate RHD among RF patients. Overcrowding (OR=2.4, 95% CI 1.2-4.7) and illiteracy (OR=2.4, 95% CI 1.1-5.2) posed the risk of RHD in the RF patients. The study did not find new factors that might pose an increased risk, rather looked for the documented risk factors and how these operate in the population of Bangladesh.Key words: Case-control study, Rheumatic fever, Rheumatic heart disease, Risk factors, Bangladesh     

Staphylococcus aureus Infections in New Zealand, 2000–2011

The incidence rate for invasive and noninvasive Staphylococcus aureus infections in New Zealand is among the highest reported in the developed world. Using nationally collated hospital discharge data, we analyzed the epidemiology of serious S. aureus infections in New Zealand during 2000–2011. During this period, incidence of S. aureus skin and soft tissue infections increased significantly while incidence of staphylococcal sepsis and pneumonia remained stable. We observed marked ethnic and sociodemographic inequality across all S. aureus infections; incidence rates for all forms of S. aureus infections were highest among Māori and Pacific Peoples and among patients residing in areas of high socioeconomic deprivation. The increased incidence of S. aureus skin and soft tissue infections, coupled with the demographic disparities, is of considerable concern. Future work should aim to reduce this disturbing national trend.     

Dietary Protein Intake and Transition between Frailty States in Octogenarians Living in New Zealand

Adequate nutritional status may influence progression to frailty. The purpose of this study is to determine the prevalence of frailty and examine the relationship between dietary protein intake and the transition between frailty states and mortality in advanced age. We used data from a longitudinal cohort study of Māori (80–90 years) and non-Māori (85 years). Dietary assessments (24-h multiple pass dietary recalls) were completed at the second year of follow-up (wave 2 and forms the baseline in this study). Frailty was defined using the Fried Frailty criteria. Multi-state modelling examined the association of protein intake and transitions between frailty states and death over four years. Over three quarters of participants were pre-frail or frail at baseline (62% and 16%, respectively). Those who were frail had a higher co-morbidity (p < 0.05), where frailty state changed, 44% showed a worsening of frailty status (robust → pre-frail or pre-frail → frail). Those with higher protein intake (g/kg body weight/day) were less likely to transition from robust to pre-frail [Hazard Ratio (95% Confidence Interval): 0.28 (0.08–0.91)] but also from pre-frail to robust [0.24 (0.06–0.93)]. Increased protein intake was associated with lower risk of transitioning from pre-frailty to death [0.19 (0.04–0.80)], and this association was moderated by energy intake [0.22 (0.03–1.71)]. Higher protein intake in this sample of octogenarians was associated with both better and worse outcomes.     

Housing conditions and adverse birth outcomes among Indigenous people in Canada

ObjectivesPoor housing conditions and household crowding have been identified as important health concerns for Indigenous populations in many countries but have not been explored in relation to adverse birth outcomes in these populations. We investigated housing conditions and adverse birth outcomes in a nationally representative sample of Indigenous people in Canada.MethodsData were from a cohort of births between May 2004 and May 2006 created by linking birth and infant death registration data with the 2006 Canadian census. Log-binomial regression was used to examine associations between housing variables (persons per room and needed household repairs) and three adverse birth outcomes: preterm birth (PTB), small-for-gestational-age (SGA) birth, and infant mortality. Separate regression models were run for First Nations, Métis and Inuit mothers, with adjustment for parity and parental socio-economic variables.ResultsNeed for major household repairs was associated with a slightly increased risk of PTB among First Nations and Métis mothers (adjusted RRs 1.12 and 1.13, respectively; 95% CI 0.94–1.34 and 0.89–1.44, respectively) and a moderately increased risk of infant death in all three groups (aRR = 1.69, 95% CI 1.00–2.85). Household crowding was also associated with a slightly elevated risk of PTB in all three groups (aRR = 1.10, 95% CI 0.95–1.29) and with an increased risk of infant mortality among First Nations (aRR = 1.57, 95% CI 0.97–2.53).ConclusionThis study highlights the need to improve understanding of links between housing conditions and perinatal health outcomes in Indigenous populations, including examining cause-specific infant mortality in relation to housing characteristics.Supplementary InformationThe online version contains supplementary material available at 10.17269/s41997-021-00527-2.     

The Frequency and Context of Snacking among Children: An Objective Analysis Using Wearable Cameras

Snacking is a common eating behaviour, but there is little objective data about children’s snacking. We aimed to determine the frequency and context of children’s snacking (n = 158; mean age = 12.6 years) by ethnicity, gender, socioeconomic deprivation and body mass index (BMI) children. Participants wore wearable cameras that passively captured images of their surroundings every seven seconds. Images (n = 739,162) were coded for snacking episodes, defined as eating occasions in between main meals. Contextual factors analysed included: snacking location, food source, timing, social contact and screen use. Rates of total, discretionary (not recommended for consumption) and healthful (recommended for consumption) snacking were calculated using negative binomial regression. On average, children consumed 8.2 (95%CI 7.4, 9.1) snacks per day, of which 5.2 (95%CI 4.6, 5.9) were discretionary foods/beverages. Children consumed more discretionary snacks than healthful snacks in each setting and at all times, including 15.0× more discretionary snacks in public spaces and 2.4× more discretionary snacks in schools. Most snacks (68.9%) were sourced from home. Girls consumed more total, discretionary and healthful snacks than boys, and Māori and Pacific consumed fewer healthful snacks than New Zealand (NZ) Europeans. Results show that children snack frequently, and that most snacking involves discretionary food items. Our findings suggest targeting home buying behaviour and environmental changes to support healthy snacking choices.     

Association of Maternal Dietary Patterns during Gestation and Offspring Neurodevelopment

The health effects of diet are long term and persistent. Few cohort studies have investigated the influence of maternal dietary patterns during different gestational periods on offspring’s health outcomes. This study investigated the associations between maternal dietary patterns in the mid- and late-gestation and infant’s neurodevelopment at 1 year of age in the Jiangsu Birth Cohort (JBC) Study. A total of 1178 mother–child pairs were available for analysis. A semiquantitative food frequency questionnaire (FFQ) was used to investigate dietary intake at 22–26 and 30–34 gestational weeks (GWs). Neurodevelopment of children aged 1 year old was assessed using Bayley-Ⅲ Screening Test. Principal component analysis (PCA) and Poisson regression were used to extract dietary patterns and to investigate the association between dietary patterns and infant neurodevelopment. After adjusting for potential confounders, the maternal ‘Aquatic products, Fresh vegetables and Homonemeae’ pattern in the second trimester was associated with a lower risk of being non-competent in cognitive and gross motor development, respectively (cognition: aRR = 0.84; 95% CI 0.74–0.94; gross motor: aRR = 0.80; 95% CI 0.71–0.91), and the similar pattern, ‘Aquatic products and Homonemeae’, in the third trimester also showed significant association with decreased risk of failing age-appreciate cognitive and receptive communication development (cognition: aRR = 0.89; 95% CI 0.80–0.98; receptive communication: aRR = 0.91; 95% CI 0.84–0.99). Notably, adherence to the dietary pattern with relatively high aquatic and homonemeae products in both trimesters demonstrated remarkable protective effects on child neurodevelopment with the risk of being non-competent in cognitive and gross motor development decreasing by 59% (95% CI 0.21–0.79) and 63% (95% CI 0.18–0.77), respectively. Our findings suggested that adherence to the ‘Aquatic products and Homonemeae’ dietary pattern during pregnancy may have optimal effects on offspring’s neurodevelopment.     

The Diet Quality and Nutrition Inadequacy of Pre-Frail Older Adults in New Zealand

This study aimed to describe the diet quality of pre-frail community-dwelling older adults to extend the evidence of nutrition in frailty prevention. Pre-frailty, the transition state between a robust state and frailty, was ascertained using the FRAIL scale. Socio-demographic, health status, and 24-h dietary recalls were collected from 465 community-dwelling adults aged 75+ (60 years for Māori and Pacific people) across New Zealand. Diet quality was ascertained with the Diet Quality Index-International (DQI-I). Participants (median (IQR) age 80 (77–84), 59% female) had a moderately healthful diet, DQI-I score: 60.3 (54.0–64.7). Women scored slightly higher than men (p = 0.042). DQI-I components identified better dietary variety in men (p = 0.044), and dietary moderation in women (p = 0.002); both sexes performed equally well in dietary adequacy and poorly in dietary balance scores (73% and 47% of maximum scores, respectively). Low energy 20.3 (15.4–25.3) kcal/kg body weight (BW) and protein intakes 0.8 (0.6–1.0) g/kg BW were coupled with a high prevalence of mineral inadequacies: calcium (86%), magnesium (68%), selenium (79%), and zinc (men 82%). In conclusion, the diet quality of pre-frail older adults was moderately high in variety and adequacy but poor in moderation and balance. Our findings support targeted dietary interventions to ameliorate frailty.     

The links between ethnicity, cultural identity and alcohol use, abuse and dependence in a new zealand birth cohort

Aims: To examine the role of ethnicity and cultural identity in alcohol use and misuse in a birth cohort of over 1000 young people. Methods: Data on ethnicity, cultural identification, alcohol use, alcohol abuse/dependence (AAD), socio-economic factors and childhood adversity were gathered as part of a longitudinal study of a New Zealand birth cohort (the Christchurch Health and Development Study). Results: Those reporting Māori ethnicity had rates of alcohol use and AAD that were 1.47-1.63 times higher than the rates found in the non-Māori people. However, there was little evidence to suggest that rates of alcohol use and AAD differed according to Māori cultural identity. Generalized estimating equation regression analyses adjusting for socio-economic disadvantage and childhood adversity slightly reduced the magnitude of these associations, but they remained statistically significant [AAD: odds ratio?=?1.52; 95% confidence interval (CI): 1.11-2.10; consumption: incidence rate ratio?=?1.31; 95% CI: 1.13-1.52]. Conclusion: (a) Māori ethnicity was found to be associated with modestly increased risks of alcohol use and AAD (b) the higher rates of alcohol use and AAD among the Māori members of the cohort could not be explained by a combination of socio-economic factors and greater exposure to environmental factors known to influence the risk of alcohol use and misuse.     

Enablers and barriers to secondary prophylaxis for rheumatic fever among Māori aged 14–21 in New Zealand: a framework method study

Background

Acute rheumatic fever (ARF) rates have declined to near zero in nearly all developed countries. However, in New Zealand rates have not declined since the 1980s. Further, ARF diagnoses in New Zealand are inequitably distributed--occurring almost exclusively in Māori (the indigenous population) and Pacific children--with very low rates in the majority New Zealand European population. With ARF diagnosis, secondary prophylaxis is key to prevent recurrence. The purpose of this study was to identify the perceived enablers and barriers to secondary recurrence prophylaxis following ARF for Māori patients aged 14–21.

Methods

This study took a systems approach, was informed by patient voice and used a framework method to explore potential barriers and enablers to ongoing adherence with monthly antibiotic injections for secondary prophylaxis. Qualitative interviews were conducted with 19 Māori ARF patients receiving recurrence prophylaxis in the Waikato District Health Board region. Participants included those fully adherent to treatment, those with intermittent adherence or those who had been “lost to follow-up.”

Results

Barriers and enablers were presented around three factors: system (including access/resources), relational and individual. Access and resources included district nurses coming to patients as an enabler and lack of income and time off work as barriers. Relational characteristics included support from family and friends as enablers and district nurse communication as predominantly a positive although not enabling factor. Individual characteristics included understanding, personal responsibility and fear/pain of injections.

Conclusion

This detailed exploration of barriers and enablers for ongoing secondary prophylaxis provides important new information for the prevention of recurrent ARF. Among other considerations, a national register, innovative engagement with youth and their families and a comprehensive pain management programme are likely to improve adherence to ongoing secondary prophylaxis and reduce the burden of RHD for New Zealand individuals, families and health system.

     

Predictors of work participation for Māori 3 months after injury

An important rehabilitation outcome for injured Māori is a timely sustainable return to work. This article identifies the factors influencing working after injury in an attempt to reduce the individual, social, and economic costs. Māori participants in the Prospective Outcomes of Injury Study were interviewed about preinjury and injury-related factors. Among Māori participants, 521 were working for pay prior to injury; 64% were working 3 months postinjury. Factors identified, using modified Poisson regression, that predicted working include financial security (aRR = 1.34, 95% CI [1.12, 1.61]), an injury of low (aRR = 1.76, 95% CI [1.26, 2.44]) or moderate severity (aRR = 1.86, 95% CI [1.34, 2.59]), professional occupations (aRR = 1.22, 95% CI [1.03, 1.44]), and jobs with less repetitive hand movement (aRR = 1.17, 95% CI [1.01, 1.34]). These factors identified warrant attention when planning interventions to enable rehabilitation back to the workplace.     

Access to chlamydia testing needed for high‐risk groups: patterns of testing and detection in an urban area of New Zealand

Objective : To describe population rates of chlamydia testing and detection by sociodemographic characteristics, and to determine whether testing is reaching those groups most at risk of infection. Methods : Laboratory data for urogenital chlamydia tests in an urban region of New Zealand were collated for the period 1999 to 2005. Census data were used to estimate rates of testing and diagnosis (per 100,000 population). Regression analyses summarised patterns in testing and diagnosis by age, sex, ethnicity and socioeconomic deprivation (controlling for potential confounding factors). Results : Rates of chlamydia testing and detection differed significantly by age, sex, ethnicity and deprivation. Females had lower rates of chlamydia diagnoses than males (OR 0.4, 95% CI 0.39–0.42) but were tested five times more often. When tested, rates of chlamydia detection were significantly higher among Pacific (OR 2.33, 95% CI 2.16–2.5), and Māori (OR 2.01, 95% CI 1.87–2.17) than among European (reference group), and among individuals living in areas of greater socioeconomic deprivation (OR 1.66, 95% CI 1.55–1.77). Chlamydia diagnoses were significantly higher in the under 25 year old age group, with the highest odds of a positive result among the 15–19 year age group (OR 9.06, 95% CI 8.23–9.98). Conclusion : This analysis identified higher‐risk groups who appeared to be underserved by testing relative to their higher rates of infection (including Māori, Pacific, 15–19 year olds and individuals living in areas of high socioeconomic deprivation). Implications : Appropriate chlamydia control programs with testing targeted towards higher‐risk groups are urgently needed in NZ.     

Racial and Ethnic Disparities in Incidence of SARS-CoV-2 Infection, 22 US States and DC,January 1–October 1, 2020

We examined disparities in cumulative incidence of severe acute respiratory syndrome coronavirus 2 by race/ethnicity, age, and sex in the United States during January 1–October 1, 2020. Hispanic/Latino and non-Hispanic Black, American Indian/Alaskan Native, and Native Hawaiian/other Pacific Islander persons had a substantially higher incidence of infection than non-Hispanic White persons.     

Prevalence of SARS-CoV-2 Antibodies in First Responders and Public Safety Personnel,New York City,New York,USA, May–July 2020

We conducted a serologic survey in public service agencies in New York City, New York, USA, during May–July 2020 to determine prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among first responders. Of 22,647 participants, 22.5% tested positive for SARS-CoV-2–specific antibodies. Seroprevalence for police and firefighters was similar to overall seroprevalence; seroprevalence was highest in correctional staff (39.2%) and emergency medical technicians (38.3%) and lowest in laboratory technicians (10.1%) and medicolegal death investigators (10.8%). Adjusted analyses demonstrated association between seropositivity and exposure to SARS-CoV-2–positive household members (adjusted odds ratio [aOR] 3.52 [95% CI 3.19–3.87]), non-Hispanic Black race or ethnicity (aOR 1.50 [95% CI 1.33–1.68]), and severe obesity (aOR 1.31 [95% CI 1.05–1.65]). Consistent glove use (aOR 1.19 [95% CI 1.06–1.33]) increased likelihood of seropositivity; use of other personal protective equipment had no association. Infection control measures, including vaccination, should be prioritized for frontline workers.     

Health system strengthening and hypertension awareness,treatment and control: data from the China Health and Retirement Longitudinal Study

Objective

To monitor hypertension prevalence, awareness, treatment and control in China two to three years after major reform of the health system.

Methods

Data from a national survey conducted in 2011–2012 among Chinese people aged 45 years or older – which included detailed anthropometric measurements – were used to estimate the prevalence of hypertension and the percentages of hypertensive individuals who were unaware of, receiving no treatment for, and/or not controlling their hypertension well. Modified Poisson regressions were used to estimate relative risks (RRs).

Findings

At the time of the survey, nearly 40% of Chinese people aged 45 years or older had a hypertensive disorder. Of the individuals with hypertension, more than 40% were unaware of their condition, about 50% were receiving no medication for it and about 80% were not controlling it well. Compared with the other hypertensive individuals, those who were members of insurance schemes that covered the costs of outpatient care were more likely to be aware of their hypertension (adjusted RR, aRR: 0.737; 95% confidence interval, CI: 0.619–0.878) to be receiving treatment for it (aRR: 0.795; 95% CI: 0.680–0.929) and to be controlling it effectively (aRR: 0.903; 95% CI: 0.817–0.996).

Conclusion

In China many cases of hypertension are going undetected and untreated, even though the health system appears to deliver effective care to individuals who are aware of their hypertension. A reduction in the costs of outpatient care to patients would probably improve the management of hypertension in China.     

SARS-CoV-2 Seroprevalence in a Rural and Urban Household Cohort during First and Second Waves of Infections,South Africa,July 2020–March 2021

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections may be underestimated because of limited access to testing. We measured SARS-CoV-2 seroprevalence in South Africa every 2 months during July 2020–March 2021 in randomly selected household cohorts in 2 communities. We compared seroprevalence to reported laboratory-confirmed infections, hospitalizations, and deaths to calculate infection–case, infection–hospitalization, and infection–fatality ratios in 2 waves of infection. Post–second wave seroprevalence ranged from 18% in the rural community children <5 years of age, to 59% in urban community adults 35–59 years of age. The second wave saw a shift in age distribution of case-patients in the urban community (from persons 35–59 years of age to persons at the extremes of age), higher attack rates in the rural community, and a higher infection–fatality ratio in the urban community. Approximately 95% of SARS-CoV-2 infections were not reported to national surveillance.