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Estimates of immunity and severity for the SARS-CoV-2 omicron subvariant BA.5 are important to assess the public health impact associated with its rapid global spread despite vaccination. We estimated natural and vaccine immunity and severity of BA.5 relative to BA.2 in Denmark, a country with high mRNA-vaccination coverage and free-of-charge RT-PCR testing.This nation-wide population-based study in Denmark included residents aged 18 years or older who had taken an RT-PCR test between 10 April and 30 June, 2022 (ie, the outcome period), and who the national COVID-19 surveillance system identified as having information since February 2020 on RT-PCR tests, whole-genome sequencing, vaccinations, and hospitalisation with a positive RT-PCR test and COVID-19 as the main diagnosis. First, we used a case-control design, in which cases were people infected with BA.5 or BA.2 during the outcome period and controls were people who tested negative for SARS-CoV-2 infection during the outcome period. We calculated the protection provided by a previous PCR-confirmed omicron infection against BA.5 and BA.2 infection and hospitalisation among triple-vaccinated individuals. Second, we compared vaccination status in people infected with BA.5 versus BA.2 and estimated relative vaccine protection against each subvariant. Third, we compared rates of hospitalisation for COVID-19 among people infected with BA.5 versus BA.2. We estimated effects using logistic regression with adjustment for sex, age, region, PCR-test date, comorbidity and, as appropriate, vaccination and previous infection status.A total of 210 (2·4%) of 8678 of BA.5 cases, 192 (0·7%) of 29 292 of BA.2 cases, and 33 972 (19·0%) of 178 669 PCR-negative controls previously had an omicron infection, which was estimated in the adjusted analyses to offer 92·7% (95% CI 91·6-93·7) protection against BA.5 infection and 97·1% (96·6-97·5) protection against BA.2 infection. We found similarly high amounts of protection against hospitalisation owing to infection with BA.5 (96·4% [95% CI 74·2-99·5]) and BA.2 (91·2% [76·3-96·7]). Vaccine coverage (three mRNA doses vs none) was 9307 (94·2%) of 9878 among BA.5 cases and 30 581 (94·8%) of 32 272 among BA.2 cases, although in the adjusted analysis, there was a trend towards slightly higher vaccination coverage among BA.5 cases than BA.2 cases (OR 1·18 [95% CI 0·99-1·42]; p=0·064), possibly suggesting marginally poorer vaccine protection against BA.5. The rate of hospitalisation due to COVID-19 was higher among the BA.5 cases (210 [1·9%] of 11 314) than among the BA.2 cases (514 [1·4%] of 36 805), with an OR of 1·34 (95% CI 1·14-1·57) and an adjusted OR of 1·69 (95% CI 1·22-2·33), despite low and stable COVID-19 hospitalisation numbers during the study period.The study provides evidence that a previous omicron infection in triple-vaccinated individuals provides high amounts of protection against BA.5 and BA.2 infections. However, protection estimates greater than 90% might be too high if individuals with a previous infection were more likely than those without one to come forward for a test for reasons other than suspicion of COVID-19. Our analysis also showed that vaccine protection against BA.5 infection was similar to, or slightly weaker than, protection against BA.2 infection. Finally, there was evidence that BA.5 infections were associated with an increased risk of hospitalisation compared with BA.2 infections.There was no funding source for this study.

The risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, hospitalization and death, and the effects of SARS-CoV-2 vaccines in solid organ transplant recipients (SOTRs) is still debated. We performed a nationwide, population-based, matched cohort study, including all Danish SOTRs (n = 5184) and a matched cohort from the general population (n = 41 472). Cox regression analyses were used to calculate incidence rate ratios (IRRs). SOTRs had a slightly increased risk of SARS-CoV-2 infection and were vaccinated earlier than the general population. The overall risk of hospital contact with COVID-19, severe COVID-19, need for assisted respiration, and hospitalization followed by death was substantially higher in SOTRs (IRR: 32.8 95%CI [29.0-37.0], 9.2 [6.7-12.7], 12.5 [7.6-20.8], 12.4 [7.9-12.7]). The risk of hospitalization and death after SARS-CoV-2 infection decreased substantially in SOTRs after the emergence of the Omicron variant (IRR: 0.45 [0.37-0.56], 0.17 [0.09-0.30]). Three vaccinations reduced the risk of SARS-CoV-2 infection only marginally compared to two vaccinations, but SOTRs with three vaccinations had a lower risk of death (IRR: 022 [0.16-0.35]). We conclude that SOTRs have a risk of SARS-CoV-2 infection comparable to the general population, but substantially increased the risk of hospitalization and death following SARS-CoV-2 infection. A third vaccination only reduces the risk of SARS-CoV2 infection marginally, but SOTRs vaccinated 3 times have reduced mortality.

Background: Within the ECDC-VEBIS project, we prospectively monitored vaccine effectiveness (VE) against COVID-19 hospitalisation and COVID-19-related death, using electronic health registries (EHR), between October 2021 and November 2022, in community-dwelling residents aged 65–79 and ≥80-years in six European countries. Methods: EHR linkage was used to construct population cohorts in Belgium, Denmark, Luxembourg, Navarre (Spain), Norway and Portugal. Using a common protocol, for each outcome (hospitalisation and death), VE was estimated monthly over eight-week follow-up periods, allowing one month-lag for data consolidation. Cox proportional-hazards regression models were used to estimate adjusted hazard ratios (aHR) and VE=(1 – aHR) x100. Site-specific estimates were pooled using random-effects meta-analysis. Results: For ≥80-years, VE against COVID-19 hospitalisation decreased from 66.9% (95%CI: 60.1; 72.6) to 36.1% (95%CI: -27.3; 67.9) for the primary vaccination and from 95.6% (95%CI: 88.0; 98.4) to 67.7% (95%CI: 45.9; 80.8) for the first booster. Similar trends were observed for 65-79-years. The second booster VE against hospitalisation ranged between 82.0% (95%CI: 75.9; 87.0) and 83.9% (95%CI: 77.7; 88.4) for the ≥80-years and between 39.3% (95%CI: -3.9; 64.5) and 80.6% (95%CI: 67.2; 88.5) for 65-79-years. The first booster VE against COVID-19-related death declined over time for both age groups, while the second booster VE against death remained above 80% for the ≥80-years. Conclusions: Successive vaccine boosters played a relevant role in maintaining protection against COVID-19 hospitalisation and death, in the context of decreasing VE over time. Multi-country data from EHR facilitate robust near-real-time monitoring of VE in the EU/EEA and supports public health decision-making.

BackgroundThe Danish national SARS-CoV-2 mass test system was among the most ambitious worldwide. We describe its set-up and analyse differences in patterns of testing per demography and time period in relation to the three waves of SARS-CoV-2 transmission in Denmark.MethodsWe included all reported PCR- and rapid antigen-tests performed between 27 February 2020 and 10 March 2022 among all residents aged 2 years or above. Descriptive statistics and Poisson regression models were used to analyse characteristics of individuals tested for SARS-CoV-2 using a national cohort study design.ResultsA total of 63.7 million PCR-tests and 60.0 million antigen-tests were performed in the study period, testing 91.1% and 79.2% of the Danish population at least once by PCR or antigen, respectively. Female sex, younger age, Danish heritage and living in the capital area were all factors positively associated with the frequency of PCR-testing. The association between COVID-19 vaccination and PCR-testing changed from negative to positive over time.ConclusionWe provide details of the widely available, free-of-charge, national SARS-CoV-2 test system, which served to identify infected individuals, assist isolation of infectious individuals and contact tracing, and thereby mitigating the spread of SARS-CoV-2 in the Danish population. The test system was utilized by nearly the entire population at least once, and widely accepted across different demographic groups. However, demographic differences in the test uptake did exist and should be considered in order not to cause biases in studies related to SARS-CoV-2, e.g., studies of transmission and vaccine effectiveness.

Lene Wulff Krogsgaard,1 Laura Espenhain,1 Siri Tribler,1 Charlotte Sværke Jørgensen,2 Christian Holm Hansen,1 Frederik Trier Møller,1 Ida Glode Helmuth,1 Ute Wolff Sönksen,3,4 Anne-Marie Vangsted,4 Henrik Ullum,5 Steen Ethelberg1,6 1Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut, Copenhagen, Denmark; 2Department of Virus & Microbiological Special Diagnostics, Statens Serum Institut, Copenhagen, Denmark; 3Department of Bacteria, Parasites and Fungi, Statens Serum Institut, Copenhagen, Denmark; 4TestCentre Denmark, Statens Serum Institut, Copenhagen, Denmark; 5Division of Infectious Disease Preparedness, Statens Serum Institut, Copenhagen, Denmark; 6Department of Public Health, University of Copenhagen, Copenhagen, DenmarkCorrespondence: Steen Ethelberg, Department of Infectious Disease Epidemiology and Prevention, Statens Serum Institut, 5 Artillerivej, 2300 Copenhagen, Denmark, Tel +45 3268 3545, Email set@ssi.dkBackground: Seroprevalence studies can be used to measure the progression of national COVID-19 epidemics. The Danish National Seroprevalence Survey of SARS-CoV-2 infections (DSS) was conducted as five separate surveys between May 2020 and May 2021. Here, we present results from the two last surveys conducted in February and May 2021.Methods: Persons aged 12 or older were randomly selected from the Danish Population Register and those having received COVID-19 vaccination subsequently excluded. Invitations to have blood drawn in local test centers were sent by mail. Samples were analyzed for whole Immunoglobulin by ELISA. Seroprevalence was estimated by sex, age and geography. Comparisons to vaccination uptake and RT-PCR test results were made.Results: In February 2021, we found detectable antibodies in 7.2% (95% CI: 6.3– 7.9%) of the invited participants (participation rate 25%) and in May 2021 in 8.6% (95% CI: 7.6– 9.5%) of the invited (participation rate: 14%). Seroprevalence did not differ by sex, but by age group, generally being higher among the < 50 than 50+ year-olds. In May 2021, levels of seroprevalence varied from an estimated 13% (95% CI: 12– 15%) in the capital to 5.2% (95% CI: 3.4– 7.4%) in rural areas. Combining seroprevalence results with vaccine coverage, estimates of protection against infection in May 2021 varied from 95% among 65+ year-olds down to 10– 20% among 12– 40 year-olds. In March–May 2021, an estimated 80% of all community SARS-CoV-2 infections were diagnosed by RT-PCR and captured by surveillance.Conclusion: Seroprevalence estimates doubled during the 2020– 21 winter wave of SARS-CoV-2 infections and then stabilized as vaccinations were rolled out. The epidemic affected large cities and younger people the most. Denmark saw comparatively low infections rates, but high test coverage; an estimated four out of five infections were detected by RT-PCR in March–May 2021.Keywords: seroepidemiological studies, COVID-19 serological testing, SARS-CoV-2, population register, questionnaire, ELISA

ObjectiveTo investigate the effectiveness of heterologous booster schedules with AZD1222 (Oxford-AstraZeneca, referred to as AZD), BNT162b2 (Pfizer-BioNTech, BNT), and mRNA-1273 (Moderna, MOD) vaccines compared with primary schedules and with homologous mRNA-vaccine booster schedules during a period of omicron predominance.DesignPopulation-based cohort analyses.SettingDenmark, Finland, Norway, and Sweden, 27 December 2020 to 28 February 2022.ParticipantsAdults that had received at least a primary vaccination schedule (ie, two doses) of the AZD, BNT, and/or MOD vaccines during the study period.Main outcome measuresUsing the Kaplan-Meier estimator, we compared country-specific risks of SARS-CoV-2 infection and severe COVID-19 outcomes in heterologous booster vaccinated with primary schedule vaccinated (matched analyses) and homologous booster vaccinated (weighted analyses) since emergence of omicron.ResultsHeterologous booster schedules improved protection against all outcomes compared with primary schedules, with the largest and most robust effects observed for severe COVID-19. Risk differences for documented infection ranged from -22.4% to -3.1% (comparative vaccine effectiveness [CVE] 9.7% to 60.9%; >63.2% for COVID-19 hospitalisation) across countries for AZD1BNT2BNT3 (AZD as primary dose followed by two doses of BNT) vs AZD1BNT2 and -22.2% to -3.2% (CVE 37.4% to 67.8%; >34.6% for hospitalisation) for BNT1BNT2MOD3 vs BNT1BNT2, the two most common heterologous booster schedules. Heterologous- and homologous booster schedules had comparable effectiveness. Risk differences of documented infection ranged from -0.4% to 4.4% (CVE -20.0% to 2.4%) for AZD1BNT2BNT3 vs BNT1BNT2BNT3 and -19.8% to 1.7% (CVE -14.6% to 53.8%) for BNT1BNT2MOD3 vs BNT1BNT2BNT3; for most comparisons, risk differences for severe COVID-19 outcomes were smaller than 1 per 1000 vaccinated. Previous infection followed by a booster dose conferred the greatest protection.ConclusionHeterologous booster vaccine schedules are associated with an increased protection against omicron-related COVID-19 outcomes that is comparable to that afforded by homologous booster schedules.

Despite increasing levels of adult hypertension in sub-Saharan Africa (SSA), there is limited information on elevated blood pressure among children in SSA. We described the distribution of blood pressure among children in rural Uganda and estimated hypertension prevalence. We conducted a cross-sectional study in south-western Uganda, collecting demographic, anthropometric and blood pressure measurements from children aged 6-12 years. Children with elevated blood pressure (systolic and/or diastolic blood pressure greater or equal to the 95th percentile for age, height and sex) were invited for two further assessments 6-18 months later. We described blood pressure distribution at first assessment, assessed associations with demographic and anthropometric characteristics and estimated prevalence of hypertension as defined by having elevated blood pressure on three separate occasions months apart. Blood pressure (BP) was measured in 1913 children (50% male, 3% overweight or obese, 22% stunted) at the first assessment. Mean (SD) systolic and diastolic BP at first assessment was 113.4 mmHg (±10.8) and 69.5 mmHg (±8.3), respectively, and 44.2% had elevated BP. Older age, higher BMI, and being female were associated with higher BP, and stunted height was associated with lower BP. An estimated 7.8% [95% CI:(6.6-9.1)], (males: 6.8%, females: 9.0%), had elevated BP on three separate occasions, and were considered hypertensive. High blood pressure levels among adults in SSA may be set early in life. In this study, obesity (a common lifestyle modifiable risk factor in other settings) was largely irrelevant. More research is needed to understand the main drivers for elevated blood pressure in SSA further.

Seroprevalence studies have proven an important tool to monitor the progression of the coronavirus disease 2019 (COVID-19) pandemic. We present results of consecutive population-based seroprevalence surveys performed in Denmark in 2020. In spring, late summer and autumn/winter of 2020, invitation letters including a questionnaire covering symptoms were sent to representative samples of the population above 12 years and to parents of children below 18 years in the sample. Blood samples were analysed for total Ig and seroprevalence estimates per population segment were calculated and compared to other surveillance parameters. Based on 34 081 participants (participation rate 33%), seroprevalence estimates increased from 1.2% (95%CI: 0.3–1.9%) in May to 4.1% (95%CI: 3.1–4.9%) in December 2020. Seroprevalence estimates were roughly three times higher in those aged 12–29 years compared to 65 + and higher in metropolitan municipalities. By December 2020, 1.5% of the population had tested positive by RT-PCR. Infected individuals in older age groups were hospitalised several fold more often than in younger. Amongst seropositives, loss of taste/smell were the more specific symptoms, 32–56% did not report any symptoms. In more than half of seroconverted families, we did not see evidence of transmission between generations. Seroprevalence increased during 2020; adolescents were primarily infected in the autumn/winter. Denmark has a high per capita test rate; roughly one undiagnosed infection of SARS-CoV-2 were estimated to occur for each diagnosed case. Approximately half were asymptomatically infected. The epidemic appears to have progressed relatively modestly during 2020 in Denmark.

The risk of severe adult respiratory coronavirus-2 (SARS-CoV-2) infection and the course of the infection among individuals with common variable immunodeficiency (CVID) relative to the general population have been a matter of debate. We conducted a Danish nationwide study comparing the timing of SARS-CoV-2 vaccination, the risk of first confirmed SARS-CoV-2 infection, re-infection, and the outcome of infection among individuals with CVID relative to an age- and gender matched control group. Cox regression was used to calculate incidence rate ratios. The CVID patients received SARS-CoV-2 vaccinations earlier than those included in the population control group. Even so, the risks of both first infection and re-infection were increased among the individuals with CVID. The CVID group also had increased risk for hospital contacts due to SARS-CoV-2 infection relative to the general population. However, reassuringly, the risk of mechanical ventilation and death did not differ between the groups, but the numbers were low in both groups, making the estimates uncertain. Though this is the largest study to investigate the risk of SARS-CoV-2 infections and outcomes hereof among individuals with CVID relative to the general population, we cannot rule out minor differences in severity, which might only be detectable with an even larger sample size.

Measures to restrict physical inter-personal contact in the community have been widely implemented during the COVID-19 pandemic. We studied determinants for infection with SARS-CoV-2 with the aim of testing the efficiency of such measures.We conducted a national matched case-control study among unvaccinated persons aged 18-49 years. Cases were selected among those testing positive for SARS-CoV-2 by RT-PCR over a five-day period in June 2021. Controls were selected from the national population register and were individually matched on age, sex and municipality of residence and had not previously tested positive. Cases and controls were interviewed via telephone about contact with other persons and exposures in the community. We included 500 cases and 529 controls and determined odds ratios (ORs) and 95% confidence intervals (95%CIs) by conditional logistical regression with adjustment for household size and immigration status.We found having had contact with another individual with a known infection as the main determinant for SARS-CoV-2 infection. Reporting close contact with an infected person who either had or did not have symptoms resulted in ORs of 20 (95%CI:9.8-39) and 8.5 (95%CI 4.5-16) respectively. In contrast, community exposures were generally not associated with disease; several exposures were negatively associated. Exceptions were: attending fitness centers, OR=1.4 (95%CI:1.0-2.0) and consumption of alcohol in restaurants or cafés, OR=2.3 (95%CI:1.3–4.2).For reference, we provide a timeline of non-pharmaceutical interventions in place in Denmark from February 2020 to March 2022. Fitness centers and alcohol consumption were mildly associated with infection, in agreement with findings of our similar study conducted six month earlier (Epidemiology & Infection 2021;150:e9.). Transmission of disease through involvement in community activities appeared to occur only rarely, suggesting that community restrictions in place were efficient. Instead, transmission appeared to primarily take place in a confined space via contact to known persons.

IntroductionIndividuals with a prior severe acute respiratory corona virus 2 (SARS-CoV-2) infection have a moderate to high degree of protection against reinfection, though seemingly less so when the Omicron variant of SARS-CoV-2 started to circulate. The aim of this study was to evaluate the vaccine effectiveness (VE) against SARS-CoV-2 reinfection, that is, in individuals with prior SARS-CoV-2 infection, during periods with different dominant SARS-CoV-2 variants.MethodsA nationwide cohort study design including all individuals with a confirmed SARS-CoV-2 infection, who were alive and residing in Denmark between 1 January 2020 and 31 January 2022 were used. Using Danish nationwide registries, we obtained information on SARS-CoV-2 infections, Coronavirus Disease 2019 (COVID-19) vaccination, age, sex, comorbidity, staying at hospital and region of affiliation. The study population included were individuals with prior SARS-CoV-2 infection. Crude and adjusted estimates of VE against SARS-CoV-2 reinfection with 95% confidence intervals (CIs) were calculated using Poisson and Cox regression models, respectively. The VE estimates were calculated separately for three periods with different dominant SARS-CoV-2 variants (Alpha (B.1.1.7), Delta (B.1.617.2), or Omicron (B.1.1.529)) and by time since vaccination using unvaccinated as the reference.FindingsThe study population comprised of 209,814 individuals infected before or during the Alpha period, 292,978 before or during the Delta period and 245,530 before or during the Omicron period. Of these, 40,281 individuals had completed their primary vaccination series during the Alpha period (19.2%), 190,026 during the Delta period (64.9%) and 158,563 during the Omicron period (64.6%). VE against reinfection following any COVID-19 vaccine type administered in Denmark, peaked at 85% (95% CI: 37% to 97%) at 104 days or more after vaccination during the Alpha period, 88% (95% CI: 81% to 92%) 14-43 days after vaccination during the Delta period and 60% (95% CI: 58% to 62%) 14-43 days after vaccination during the Omicron period. Waning immunity was observed, and was most pronounced during the Omicron period.InterpretationThis study shows that, in previously infected individuals, completing a primary vaccination series was associated with a significant protection against SARS-CoV-2 reinfection compared with no vaccination for all three variant periods. Even though vaccination seems to protect to a lesser degree against reinfection with the Omicron variant, these findings are of public health relevance as they show that previously infected individuals still benefit from COVID-19 vaccination in all three variant periods.

BackgroundThe continued occurrence of more contagious SARS-CoV-2 variants and waning immunity over time require ongoing re-evaluation of the vaccine effectiveness (VE). This study aimed to estimate the effectiveness in two age groups (12-59 and 60 years or above) of two and three vaccine doses (BNT162b2 mRNA or mRNA-1273 vaccine) by time since vaccination against SARS-CoV-2 infection and COVID-19-related hospitalization in an Alpha, Delta and Omicron dominated period.MethodsA Danish nationwide cohort study design was used to estimate VE against SARS-CoV-2 infection and COVID-19-related hospitalization with the Alpha, Delta and Omicron variants. Information was obtained from nationwide registries and linked using a unique personal identification number. The study included all residents in Denmark aged 12 years or above (18 years or above for the analysis of three doses) in the Alpha (February 20 to June 15, 2021), Delta (July 4 to November 20, 2021) and Omicron (December 21, 2021 to January 31, 2022) dominated periods. VE estimates including 95% confidence intervals (CIs) were calculated using Cox proportional hazard regression models with adjustments for age, sex and geographical region. Vaccination status was included as a time-varying exposure.FindingsIn the oldest age group, VE against infection after two doses was 91.0% (95% CI: 88.5; 92.9) for the Alpha variant, 82.2% (95% CI: 75.3; 87.1) for the Delta variant and 39.9% (95% CI: 26.4; 50.9) for the Omicron variant 14-30 days since vaccination. The VE waned over time and was 71.5% (95% CI: 54.7; 82.8), 49.8% (95% CI: 46.5; 52.8) and 4.7% (95% CI: 0.2; 8.9) >120 days since vaccination against the three variants, respectively. Higher estimates were observed after the third dose with VE estimates against infection of 86.0% (Delta, 95% CI: 83.3; 88.3) and 57.6% (Omicron, 95% CI: 55.8; 59.4) 14-30 days since vaccination. Among both age groups, VE against COVID-19-related hospitalization 14-30 days since vaccination with two or three doses was 94.8% or above for the Alpha and Delta variants, whereas among the youngest age group, VE estimates against the Omicron variant after two and three doses were 62.4% (95% CI: 46.3; 73.6) and 89.8% (95% CI: 87.9; 91.3), respectively.ConclusionsTwo vaccine doses provided high protection against SARS-CoV-2 infection and COVID-19-related hospitalization with the Alpha and Delta variants with protection waning over time. Two vaccine doses provided only limited protection against SARS-CoV-2 infection and COVID-19-related hospitalization with the Omicron variant. The third vaccine dose substantially increased the protection against Delta and Omicron.

Summary Background The degree to which infection with SARS-CoV-2 confers protection towards subsequent reinfection is not well described. In 2020, as part of Denmark's extensive, free-of-charge PCR-testing strategy, approximately 4 million individuals (69% of the population) underwent 10·6 million tests. Using these national PCR-test data from 2020, we estimated protection towards repeat infection with SARS-CoV-2. Methods In this population-level observational study, we collected individual-level data on patients who had been tested in Denmark in 2020 from the Danish Microbiology Database and analysed infection rates during the second surge of the COVID-19 epidemic, from Sept 1 to Dec 31, 2020, by comparison of infection rates between individuals with positive and negative PCR tests during the first surge (March to May, 2020). For the main analysis, we excluded people who tested positive for the first time between the two surges and those who died before the second surge. We did an alternative cohort analysis, in which we compared infection rates throughout the year between those with and without a previous confirmed infection at least 3 months earlier, irrespective of date. We also investigated whether differences were found by age group, sex, and time since infection in the alternative cohort analysis. We calculated rate ratios (RRs) adjusted for potential confounders and estimated protection against repeat infection as 1 – RR. Findings During the first surge (ie, before June, 2020), 533 381 people were tested, of whom 11 727 (2·20%) were PCR positive, and 525 339 were eligible for follow-up in the second surge, of whom 11 068 (2·11%) had tested positive during the first surge. Among eligible PCR-positive individuals from the first surge of the epidemic, 72 (0·65% [95% CI 0·51–0·82]) tested positive again during the second surge compared with 16 819 (3·27% [3·22–3·32]) of 514 271 who tested negative during the first surge (adjusted RR 0·195 [95% CI 0·155–0·246]). Protection against repeat infection was 80·5% (95% CI 75·4–84·5). The alternative cohort analysis gave similar estimates (adjusted RR 0·212 [0·179–0·251], estimated protection 78·8% [74·9–82·1]). In the alternative cohort analysis, among those aged 65 years and older, observed protection against repeat infection was 47·1% (95% CI 24·7–62·8). We found no difference in estimated protection against repeat infection by sex (male 78·4% [72·1–83·2] vs female 79·1% [73·9–83·3]) or evidence of waning protection over time (3–6 months of follow-up 79·3% [74·4–83·3] vs ≥7 months of follow-up 77·7% [70·9–82·9]). Interpretation Our findings could inform decisions on which groups should be vaccinated and advocate for vaccination of previously infected individuals because natural protection, especially among older people, cannot be relied on. Funding None.

Background: The level of protection after a SARS-CoV-2 infection against reinfection and COVID-19 disease remains important with much of the world still unvaccinated. Methods: Analysing nationwide, individually referable, Danish register data including RT-PCR-test results, we conducted a cohort study using Cox regression to compare SARS-CoV-2 infection rates before and after a primary infection among still unvaccinated individuals, adjusting for sex, age, comorbidity and residency region. Estimates of protection against infection were calculated as 1 minus the hazard ratio. Estimates of protection against symptomatic infections and infections leading to hospitalisation were also calculated. The prevalence of infections classified as symptomatic or asymptomatic was compared for primary infections and reinfections. The study also assessed protection against each of the main viral variants after a primary infection with an earlier variant by restricting follow-up time to distinct, mutually exclusive periods during which each variant dominated. Findings: Until 1 July 2021 the estimated protection against reinfection was 83.4% (95%CI: 82.2–84.6%); but lower for the 65+ year-olds (72.2%; 95%CI: 53.2–81.0%). Moderately higher estimates were found for protection against symptomatic disease, 88.3% overall (95%CI: 85.9–90.3%). First-time cases who reported no symptoms were more likely to experience a reinfection (odds ratio: 1.48; 95%CI: 1.35–1.62). By autumn 2021, when infections were almost exclusively caused by the Delta variant, the estimated protection following a recent first infection was 91.3% (95%CI: 89.7–92.7%) compared to 71.4% (95%CI: 66.9–75.3%) after a first infection over a year earlier. With Omicron, a first infection with an earlier variant in the past 3-6 months gave an estimated 51.0% (95%CI: 50.1–52.0%) protection, whereas a first infection longer than 12 months earlier provided only 19.0% (95%CI: 17.2–20.5%) protection. Protection by an earlier variant-infection against hospitalisation due to a new infection was estimated at: 86.6% (95%CI: 46.3–96.7%) for Alpha, 97.2% (95%CI: 89.0–99.3%) for Delta, and 69.8% (95%CI: 51.5–81.2%) for the Omicron variant. Interpretation: SARS-CoV-2 infection offered a high level of sustained protection against reinfection, comparable with that offered by vaccines, but decreased with the introduction of new main virus variants; dramatically so when Omicron appeared. Protection was lower among the elderly but appeared more pronounced following symptomatic compared to asymptomatic infections. The level of estimated protection against serious disease was somewhat higher than that against infection and possibly longer lasting. Decreases in protection against reinfection, seemed primarily to be driven by viral evolution. Funding: None.

The burden of kidney disease in many African countries is unknown. Equations used to estimate kidney function from serum creatinine have limited regional validation. We sought to determine the most accurate way to measure kidney function and thus estimate the prevalence of impaired kidney function in African populations.We measured serum creatinine, cystatin C, and glomerular filtration rate (GFR) using the slope-intercept method for iohexol plasma clearance (mGFR) in population cohorts from Malawi, Uganda, and South Africa. We compared performance of creatinine and cystatin C-based estimating equations to mGFR, modelled and validated a new creatinine-based equation, and developed a multiple imputation model trained on the mGFR sample using age, sex, and creatinine as the variables to predict the population prevalence of impaired kidney function in west, east, and southern Africa.Of 3025 people who underwent measured GFR testing (Malawi n=1020, South Africa n=986, and Uganda n=1019), we analysed data for 2578 participants who had complete data and adequate quality measurements. Among 2578 included participants, creatinine-based equations overestimated kidney function compared with mGFR, worsened by use of ethnicity coefficients. The greatest bias occurred at low kidney function, such that the proportion with GFR of less than 60 mL/min per 1·73 mEstimating GFR using serum creatinine substantially underestimates the individual and population-level burden of impaired kidney function in Africa with implications for understanding disease progression and complications, clinical care, and service provision. Scalable and affordable ways to accurately identify impaired kidney function in Africa are urgently needed.The GSK Africa Non-Communicable Disease Open Lab.For the Luganda, Chichewa and Xitsonga translations of the abstract see Supplementary Materials section.

IntroductionViolence against women is a global public health concern; around a quarter of women will experience intimate partner physical or sexual violence during their lifetime. We assessed the impact of a gender transformative intervention for women designed to prevent intimate partner violence (IPV).MethodsWe conducted a cluster randomised controlled trial in Mwanza city, Tanzania, among women in newly formed neighbourhood groups to evaluate a 10-session participatory intervention that aims to empower women, prevent IPV and promote healthy relationships. Following a baseline interview, groups were randomly assigned (1:1 ratio) to the intervention or control arm. An intention-to-treat analysis was conducted to assess the impact of the intervention on the main outcomes, assessed 24 months postintervention. These included past-year physical IPV and sexual IPV (primary); past-year emotional abuse; and acceptability and tolerance of IPV.ResultsBetween September 2015 and February 2017, 1265 women were recruited in 66 neighbourhoods and randomly allocated to intervention (n=627 women in 33 neighbourhoods) or control (n=638 women in 33 neighbourhoods). Assessment of outcomes was completed for 551 (88%) intervention and 575 (90%) control women. Among intervention women, 113 (21%) reported physical IPV compared with 117 (20%) control women (adjusted OR (aOR) 0.98, 95% CI 0.72 to 1.33, p=0.892), and 109 (20%) intervention women reported sexual IPV compared with 121 (21%) control women (aOR 0.98, 95% CI 0.72 to 1.32, p=0.881). Intervention women reported less emotional abuse (aOR 0.74, 95% CI 0.56 to 0.98, p=0.035), and were less likely to express attitudes accepting of IPV (aOR 0.49, 95% CI 0.36 to 0.66, pConclusionThese results indicate that the intervention was effective in reducing emotional abuse and positively impacting attitudes and beliefs condoning IPV, but was not sufficient to reduce physical or sexual IPV.Trial registration numberNCT02592252.

Background Soil-transmitted helminth (STH) infections are highly prevalent in resource-limited countries. We assessed the effect of a combination intervention aiming to enhance handwashing with soap on STH reinfection following mass drug administration among primary school children in Kagera region, Northwestern Tanzania. Methods We conducted a cluster randomised trial in sixteen primary schools with known high STH prevalence. Schools were randomly assigned in a 1:1 ratio to either receive the intervention or continue with routine health education. The intervention included teacher-led classroom teaching, parental engagement sessions, environmental modifications and improved handwashing stations. The evaluation involved two cross-sectional surveys in a representative sample of students, with the end-line survey conducted 12 months after the baseline survey. The primary outcome was the combined prevalence of Ascaris lumbricoides and Trichuris trichiura infections at the end-line survey. Secondary outcomes included reported handwashing behaviour, the prevalence and intensity of individual STHs, and hand contamination with STH ova and coliform bacteria. End-line STH prevalence and intensity were adjusted for baseline differences of potential confounders. Results At the end-line survey, 3081 school children (1566 from intervention schools and 1515 from control schools) provided interview data and stool specimens. More school children in the intervention group reported the use of water and soap during handwashing compared to school children in the control group (58% vs. 35%; aOR=1.76, 95%CI 1.28–2.43, p=0.001). The combined prevalence of A. lumbricoides and T. trichiura infections was 39% in both trial arms (aOR = 1.19; 95%CI 0.74–1.91). The prevalence of A. lumbricoides was 15% in the intervention and 17% in the control arm (aOR =1.24, 95%CI 0.59–2.59) and that of T. trichiura was 31% in both arms (aOR=1.17, 95%CI 0.73–1.88). No significant differences were found for STH infection intensity in both the main study and the hand contamination sub-study. Conclusions The intervention was effective in increasing reported handwashing behaviour at school, but failed to show a similar effect in the home. The intervention had no effect on STH infection, possibly due to infection in the home environment, other transmission routes such as contaminated water or food or limited changes in school children’s handwashing behaviour. Trial registration The trial was registered on June 21, 2017, by the International Standard Randomised Controlled Trial Number (ISRCTN45013173).

Despite increasing levels of adult hypertension in sub-Saharan Africa (SSA), there is limited information on elevated blood pressure among children in SSA. We described the distribution of blood pressure among children in rural Uganda and estimated hypertension prevalence. We conducted a cross-sectional study in south-western Uganda, collecting demographic, anthropometric and blood pressure measurements from children aged 6-12 years. Children with elevated blood pressure (systolic and/or diastolic blood pressure greater or equal to the 95th percentile for age, height and sex) were invited for two further assessments 6-18 months later. We described blood pressure distribution at first assessment, assessed associations with demographic and anthropometric characteristics and estimated prevalence of hypertension as defined by having elevated blood pressure on three separate occasions months apart. Blood pressure (BP) was measured in 1913 children (50% male, 3% overweight or obese, 22% stunted) at the first assessment. Mean (SD) systolic and diastolic BP at first assessment was 113.4 mmHg (±10.8) and 69.5 mmHg (±8.3), respectively, and 44.2% had elevated BP. Older age, higher BMI, and being female were associated with higher BP, and stunted height was associated with lower BP. An estimated 7.8% [95% CI:(6.6-9.1)], (males: 6.8%, females: 9.0%), had elevated BP on three separate occasions, and were considered hypertensive. High blood pressure levels among adults in SSA may be set early in life. In this study, obesity (a common lifestyle modifiable risk factor in other settings) was largely irrelevant. More research is needed to understand the main drivers for elevated blood pressure in SSA further.

Objective To compare self-reported outcomes, clinical trajectory and utility of baseline questionnaire responses in predicting prognosis in functional and recognised pathophysiological neurological disorders. Methods Baseline data on 2581 patients included health-related quality of life, psychological and physical symptoms, illness perceptions, consultation satisfaction and demographics. The prospective cohort included neurology outpatients classified with a functional (reporting symptoms ‘not at all’ or ‘somewhat explained’ by ‘organic disease’; n = 716) or recognised pathophysiological disorder (‘largely’ or ‘completely explained’; n = 1865). Logistic regression and deep neural network models were used to predict self-reported global clinical improvement (CGI) at 12-months. Results Patients with functional and recognised pathophysiological disorders reported near identical outcomes at 12-months with 67% and 66% respectively reporting unchanged or worse CGI. In multivariable modelling ‘negative expectation of recovery’ and ‘disagreement with psychological attribution’ predicted same or worse outcome in both groups. Receipt of disability-related state benefit predicted same or worse CGI outcome in the functional disorder group only (OR = 2.28 (95%-CI: 1.36–3.84) in a group-stratified model) and was not related to a measure of economic deprivation. Deep neural network models trained on all 92 baseline features predicted poor outcome with area under the receiver-operator curve of 0.67 in both groups. Conclusions Those with functional and recognised pathophysiological neurological disorder share similar outcomes, clinical trajectories, and poor prognostic markers in multivariable models. Prediction of outcome at a patient level was not possible using the baseline data in this study.

Introduction: The burden of kidney disease in sub-Saharan Africa is currently poorly understood. Very limited monitoring and treatment is available for people affected. The association with other diseases and with mortality is unknown in this setting. We sought to determine the association between kidney function and subsequent all-cause mortality. Methods: In a general population cohort with detailed measurement of health-related parameters in rural Uganda, we estimated the baseline glomerular filtration rate (GFR) between 2011-2014 in 5,678 participants. We followed participants up to March 2019 with regular ascertainment of mortality and migration. Using multivariable cox regression, we determined associations between baseline eGFR and mortality. Results: The median age of the participants at baseline was 36 years (IQR 24-50), 60.7% were female, 14.6% hypertensive, 9.7% HIV-positive and 1.8% diabetic. We registered 140 deaths with a median follow-up of 5.0 years. Adjusting for age and sex, HIV, hypertension, diabetes, BMI, marital status, and alcohol and tobacco use participants with eGFR ≤45 mls/min/1.73m2 had six-fold higher mortality compared to those with eGFR ≥90mls/min/1.73m2 (HR 6.12 (95% CI 2.27-16.45)) with strong evidence of a linear trend for risk of mortality as renal function declined (P

ObjectivesCervical cancer is the leading cause of cancer-related mortality among women in sub-Saharan Africa (SSA). Data on human papillomavirus (HPV) epidemiology in adolescent girls in SSA are essential to inform HPV vaccine policy recommendations for cervical cancer prevention. We assessed the burden of HPV infection, and risk factors for infection, among adolescent girls around the time of sexual debut.MethodsCross-sectional study of secondary school girls aged 17–18 years in Tanzania. Consenting participants provided samples for HPV and STI testing. Vaginal swabs were tested for 37 HPV genotypes by Roche Linear Array. Logistic regression was used to identify factors associated with HPV infection. Y chromosome was tested as a marker of recent condomless sex.Results163/385 girls (42.3%) reported previous penetrative sex. HPV was detected in 125/385 (32.5%) girls, including 84/163 (51.5%) girls reporting previous sex and 41/222 (18.5%) reporting no previous sex. High-risk (HR) genotypes were detected in 70/125 (56.0%) girls with HPV infection. The most common HR genotype was HPV-16 (15/385; 3.9%). The prevalence of other HR HPV vaccine genotypes was between 0.8% and 3.1%. Among 186 girls who reported no previous sex, were negative for Y chromosome, and had no STI, 32 (17%) had detectable HPV. Lactobacillus sp and bacterial vaginosis-associated bacteria were negatively and positively associated, respectively, with HPV.ConclusionsHPV prevalence among adolescent girls around the time of sexual debut was high. However, prevalence of most vaccine genotypes was low, indicating that extending the age range of HPV vaccination in this region may be cost-effective.

We conducted a cross‐sectional study among school/college students in Tanzania and Uganda to determine the prevalence of high blood pressure (BP) and associated factors. Participants were classified to have high BP if they had pre‐hypertension or hypertension. Interviews were done using the WHO STEPS instrument. Using data from both countries (n = 1596), the overall prevalence of high BP was 40% (95% CI: 37‐42). The prevalence of pre‐hypertension was 29% (95% CI: 26‐31) and that of hypertension was 11% (95% CI: 10‐13). High BP was independently associated with obesity (aOR = 6.7, 95% CI: 2.2‐20.0), male sex (aOR = 3.2, 95% CI: 2.4‐4.4), and among males aged above 20 years (aOR = 5.5, 95% CI: 2.9−10.5). Consumption of fruits/vegetables was associated with decreased odds for high BP (aOR = 0.7, 95% CI: 0.50‐0.98). The increasing burden of pre‐hypertension across age groups could explain the early onset of hypertension and cardiovascular diseases (CVDs) among young African adults. There is a need for longitudinal studies to explore the drivers of pre‐hypertension in East African adolescents.

ObjectivesBacterial vaginosis (BV) increases women’s susceptibility to sexually transmitted infections (STIs) and HIV and may partly explain the high incidence of STI/HIV among girls and young women in East and southern Africa. The objectives of this study were to investigate the association between BV and sexual debut, to investigate other potential risk factors of BV and to estimate associations between BV and STIs.MethodsSecondary school girls in Mwanza, aged 17 and 18 years, were invited to join a cross-sectional study. Consenting participants were interviewed and samples were obtained for STI and BV testing. Factors associated with prevalent BV were analysed using multivariable logistic regression. Y-chromosome was tested as a biomarker for unprotected penile-vaginal sex.ResultsOf the 386 girls who were enrolled, 163 (42%) reported having ever had penile-vaginal sex. Ninety-five (25%) girls had BV. The prevalence of BV was 33% and 19% among girls who reported or did not report having ever had penile-vaginal sex, respectively. BV was weakly associated with having ever had one sex partner (adjusted odds ratio (aOR) 1.59;95% CI 0.93 to 2.71) and strongly associated with two or more partners (aOR = 3.67; 95% CI 1.75 to 7.72), receptive oral sex (aOR 6.38; 95% CI 1.22 to 33.4) and having prevalent human papillomavirus infection (aOR = 1.73; 95% CI 1.02 to 2.95). Of the 223 girls who reported no penile-vaginal sex, 12 (5%) tested positive for an STI and 7 (3%) tested positive for Y-chromosome. Reclassifying these positive participants as having ever had sex did not change the key results.ConclusionsTanzanian girls attending school had a high prevalence of BV. Increasing number of sex partner was associated with BV; however, 19% of girls who reported no penile-vaginal sex had BV. This suggests that penile-vaginal sexual exposure may not be a prerequisite for BV. There was evidence of under-reporting of sexual debut.

Background: The degree to which infection with SARS-CoV-2 confers immunity towards subsequent infection is not yet known. In 2020, as part of Denmark’s extensive, free-of-charge PCR-testing strategy, 4 million individuals (69% of the population) underwent 10.6 million tests. Using these national PCR-test data from 2020, we estimated the natural immunity towards SARS-CoV-2 after infection and investigated differences by age, sex and time since infection. Methods: Analysing the second surge of the epidemic (September–December, 2020) we compared infection rates between those with and without a previous positive test from the first surge (March–May). In an alternative time-to-event analysis, we compared infection rates throughout the year between those with and without a previous confirmed infection three or more months earlier. Rate ratios were adjusted for potential cofounders and natural immunity was estimated as one minus the rate ratio. Findings: Among PCR positive individuals from the first surge, 0·65% tested positive again during the second surge compared with 3·3% without a previous infection. The natural immunity was 80·5% (95% CI 75·4–84·5). The time-to-event analysis gave a similar estimate, as did the use of two and four months’ separation between repeat positive tests, and limiting the cohort to frequently tested health staff only. Among those aged 65+ years, observed immunity was 47% (95% CI 24·7–62·8). There was no difference in immunity by sex or evidence of waning immunity over time. Interpretation: Person-identifiable test results from large scale national PCR-testing in Denmark suggest that the within-season immunity following symptomatic or non-symptomatic infection is around 80%, although significantly lower in the elderly. These findings may inform decisions of which groups to vaccinate and advocate for vaccination of previously infected individuals as natural protection among elderly citizens cannot be relied upon. Funding: No designated funding was received for this study. DM was funded by the European Centers for Disease Control and Prevention programme EUPHEM. Declaration of Interests: All authors declare no competing interests. Ethics Approval Statement: The present study was based on existing administrative data and did not require ethical approval.

Background: Quantifying the risk of infection with SARS-CoV-2 associated with community exposures, may provide an evidence base for implementing preventive measures. Here, we investigated potential determinants for infection in Denmark in a situation where society was only partially open. Methods: We conducted a national matched case-control study. Cases were recent RT-PCR test-positives, while controls, individually matched on age, sex and residence, had not previously tested positive for SARS-CoV-2. Questions concerned person contact and community exposures. Telephone interviews were performed over a seven-day period in December 2020. We included 300 cases and 317 controls and determined odds ratios (ORs) and 95% confidence intervals (95%CI) by conditional logistical regression with adjustment for household size and country of origin. Findings: Contact (OR=4·9,95%CI:2·4-10), and close contact (OR=13, 95%CI:6·7-25), with a person with a known SARS-CoV-2 infection were main determinants. Contact most often took place in the household or work place. Community determinants included: events with singing (OR=2.1, 95%CI:1·1-4·1), attending fitness centre (OR=1·8, 95%CI:1·1-2·8) and consumption of alcohol in a bar (OR=10, 95%CI:1·5-65). Other community exposures appeared not to be associated with infection, these included shopping at supermarkets, travel by public transport, dining at restaurants and private social events with few participants. Interpretations: Events with singing and fitness centres were associated with transmission risks. Other than that, the restrictions in place at the time of the study appeared to be sufficient to reduce transmission of disease in the public space, which instead took place following direct exposures to people with known SARS-CoV-2 infections. Funding Information: None. Declaration of Interests: All authors have nothing to declare. Ethics Approval Statement: The study was performed as a national disease surveillance project, registered with the Danish Data Protection Agency (reg no 20/10133) and approved regarding legal, ethical and cyber-security issues. Participation was voluntary and participants received information about the selection procedure, risks associated with participation, data security, legal rights, including the right to withdraw from the study, and the use of their information at the start of the interview. The collaboration with the polling company was regulated by a data processing agreement and carried out on commercial terms.

Background: Rift Valley fever (RVF) is an emerging, neglected, mosquito-borne viral haemorrhagic zoonosis associated with severe morbidity, mortality and expanding geographical scope. Human symptoms have poor specificity and case definitions vary. We determined the clinical manifestations of RVF in humans. Methods: In this systematic review and meta-analysis we searched Medline, Embase, Global Health, and Web of Science databases from indexing inception to 15th October 2019. Studies published in English, reporting frequency of symptoms in humans, and laboratory confirmed RVF were included. Animals studies, those among asymptomatic volunteers and single case reports for which a proportion could not be estimated were excluded. Quality assessment was done, data extracted, and pooled frequency estimates calculated using random effects meta-analysis. Results: Of the 3765 articles retrieved, 32 were included in the systematic review and meta-analysis. Nine RVF clinical syndromes were reported including general febrile, gastrointestinal, hepatic, renal, neurological, haemorrhagic, obstetric, visual, and cardio-pulmonary syndromes. The most common clinical manifestations included fever (81%; 95% Confidence Interval (CI) 69-91), nausea (38%; 12-67), jaundice (26%; 16-36), renal failure (41%; 23-59), encephalitis (21%; 11-33), haemorrhagic disease (26%; 17-36), miscarriage (54%), partial blindness (24%; 7-45), and cough (4%; 0-17), respectively. Death occurred in 21% (95% CI 14-29) of cases. Interpretation: This study delineates the complex symptomatology of human RVF disease into syndromes. This approach is likely to improve case definitions and detection rates, impact outbreaks control, increase public awareness about RVF, and subsequently inform ‘one-health’ policies. Study protocol registration number: CRD42019128928. Funding: (UK Department of Health and Social care) The work was conducted at the MRC/UVRI and LSHTM Uganda Research Unit which is jointly funded by the UK Medical Research Council (MRC) and the UK Department for International Development (DFID) under the MRC/DFID Concordant agreement and is also part of the EDCTP2 programme supported by the European Union. This project was funded by the UK Biotechnology and Biological Sciences Research Council (BBSRC) and the Medical Research Council (MRC)/Department of Health, through the UK Vaccines Network which is a Government Funding Stream (Grant no: 16/107/02). SL was supported by the PANDORA-ID-NET Consortium (EDCTP Reg/Grant RIA2016E-1609) funded by the European and Developing Countries Clinical Trials Partnership (EDCTP2) programme under the Horizon 2020, the European Union’s Framework Programme for Research and Innovation. GMW is supported by an Oak foundation fellowship and a Wellcome Trust grant (grant number 203077_Z_16_Z). Declaration of Interests: All authors declare no potential conflicts of interest.

To quantify the burden of HIV, syphilis and schistosome infection and associated risk factors among adults living in seven fishing communities of Lake Victoria in northwest Tanzania.Cross-sectional study conducted between 2015 and 2016 in the selected communities. In each community, we randomly selected a sample of adults from the general population and from three putative risk groups including the following: (i) fishermen, (ii) fish processors and traders, and (iii) women working in the recreational facilities. Participants were interviewed to obtain information about potential risk factors, and venous blood was collected for detection of HIV, syphilis and schistosome infections. We used logistic regression models to quantify the associations between potential risk factors and HIV, and also between schistosome infection and HIV.We enrolled 1128 people from selected fishing communities. The overall prevalence of HIV, syphilis and schistosome infection was 14.2%, 15.6% and 83.1%, respectively. Female recreational facility workers had the highest prevalence of HIV (30.4%) and syphilis (24%). The odds of being HIV infected were generally higher in all age categories. Transactional sex was commonly reported and especially receiving gifts for sex was found to be strongly associated with HIV (adjusted OR = 2.50; 95% CI: 1.44-4.34, P = 0.008). Confirmed serological syphilis was associated with increased odds of having HIV infection. HIV was not associated with schistosome infection in a combined dataset and when we examined this separately for men and women alone.We observed a high burden of HIV, syphilis and schistosome infections in the fishing communities. Targeted efforts to treat and control infections have the potential to improve health among their residents.Quantifier la charge du VIH, de la syphilis et de l’infection à schistosomes et les facteurs de risque associés chez les adultes vivant dans sept communautés de pêcheurs du lac Victoria dans le nord-ouest de la Tanzanie. MÉTHODES: Etude transversale menée entre 2015-2016 dans les communautés sélectionnées. Dans chaque communauté, nous avons sélectionné aléatoirement un échantillon d'adultes de la population générale et de trois groupes à risque présumés, notamment: 1) les pêcheurs, 2) les transformateurs et commerçants de poisson et 3) les femmes travaillant dans les établissements de loisirs. Les participants ont été interrogés pour obtenir des informations sur les facteurs de risque potentiels, et du sang veineux a été collecté pour la détection du VIH, de la syphilis et des infections à schistosome. Nous avons utilisé des modèles de régression logistique pour quantifier les associations entre les facteurs de risque potentiels et le VIH, ainsi qu'entre l'infection à schistosome et le VIH. RÉSULTATS: Nous avons recruté 1.128 personnes dans une sélection de communautés de pêcheurs. La prévalence globale de l'infection par le VIH, la syphilis et les schistosomes était de 14,2%, 15,6% et 83,1% respectivement. Les travailleuses des établissements de loisirs avaient la prévalence la plus élevée du VIH (30,4%) et de la syphilis (24%). Les chances d'être infecté par le VIH étaient généralement plus élevées dans toutes les catégories d'âge. Les rapports sexuels transactionnels étaient fréquemment rapportés et surtout le fait de recevoir des cadeaux pour le sexe était fortement associé au VIH (OR ajusté = 2,50; IC95%: 1,44-4,34 ; P = 0,008). La syphilis sérologique confirmée était associée à une probabilité accrue d'être infecté par le VIH. Le VIH n'était pas associé à une infection à schistosome dans un ensemble de données combinées et lorsque nous avons examiné cela séparément pour les hommes et les femmes.Nous avons observé une charge élevée d'infections par le VIH, la syphilis et les schistosomes dans les communautés de pêcheurs. Des efforts ciblés pour traiter et contrôler les infections ont le potentiel d'améliorer la santé des résidents.

Introduction Soil transmitted helminths (STH) can affect over 50% of children in some parts of Tanzania. Control measures involve annual deworming campaigns in schools, but re-infection is rapid. This paper presents the design and baseline survey results of an ongoing school-based cluster-randomised controlled trial in Kagera region, NW Tanzania. The trial aims to determine whether the effect of routine deworming on the prevalence of Ascaris lumbricoides and Trichuris trichiura infections among school aged children can be sustained when combined with a behaviour change intervention promoting handwashing with water and soap. Methods As part of the trial, a total of 16 schools were randomised to receive the intervention (N = 8) or as controls (N = 8). Randomisation was stratified per district and restricted to ensure pre-trial STH prevalence was balanced between study arms. The combination intervention to be tested comprises class-room based teacher-led health education, improvement of handwash stations, coloured nudges to facilitate handwashing and parental engagement sessions. The impact evaluation involves two cross-sectional surveys conducted at baseline and endline. The objectives of the baseline survey were: (i) to confirm whether the deworming campaign was successful, and identify and treat students still infected about 2 weeks after deworming, (ii) to document any baseline differences in STH prevalence between trial arms, and (iii) to assess handwashing behaviours, and access to water and sanitation at school and home. We randomly sampled 35 students per class in Grades 1–6 (an average of 200 children per school), stratified to ensure equal representation between genders. Assenting students were interviewed using a structured questionnaire and asked to provide a stool specimen. Results Results of the baseline survey conducted about 2 weeks after deworming shows balanced demographic and STH prevalence data across trial arms. We observed a low prevalence of ascariasis (< 5%) as expected; however, the prevalence of trichuriasis was still about 35% in both arms. Conclusion The randomisation procedure was successful in achieving a balanced distribution of demographic characteristics and helminth infections between trial arms. The intervention is being rolled out. The current deworming treatment regimen may need to be revised with regards to the treatment of trichuriasis.

Background Chronic kidney disease (CKD) is a substantial cause of morbidity and mortality worldwide with disproportionate effects in sub-Saharan Africa (SSA). The optimal methods to estimate glomerular filtration rate (GFR) and therefore to determine the presence of CKD in SSA are uncertain. We plan to measure iohexol excretion to accurately determine GFR in Malawi, South Africa and Uganda. We will then assess the performance of existing equations to estimate GFR and determine whether a modified equation can better improve estimation of GFR in sub-Saharan Africa. Methods The African Research on Kidney Disease (ARK) study is a three-country study embedded within existing cohorts. We seek to enrol 3000 adults > 18 years based on baseline serum creatinine. Study procedures include questionnaires on socio-demographics and established risk factors for kidney disease along with anthropometry, body composition, blood pressure, blood chemistry and urine microscopy and albuminuria. We will measure GFR (mGFR) by plasma clearance of iohexol at 120, 180 and 240 min. We will compare eGFR determined by established equations with mGFR using Bland-Altman plots. We will use regression methods to estimate GFR and compare the newly derived model with existing equations. Discussion Through the ARK study, we aim to establish the optimal approach to estimate GFR in SSA. The study has the advantage of drawing participants from three countries, which will increase the applicability of the findings across the region. It is also embedded within established cohorts that have longitudinal information and serial measures that can be used to characterize kidney disease over a period of time. This will help to overcome the limitations of previous research, including small numbers, selected population sub-groups, and lack of data on proteinuria. The ARK collaboration provides an opportunity for close working partnerships across different centres, using standardized protocols and measurements, and shared bio-repositories. We plan to build on the collaboration for this study for future work on kidney disease in sub-Saharan Africa, and welcome additional partners from across the continent.

Background There are 2.5 million neonatal deaths each year; the majority occur within 48 h of birth, before stabilisation. Evidence from 11 trials shows that kangaroo mother care (KMC) significantly reduces mortality in stabilised neonates; however, data on its effect among neonates before stabilisation are lacking. The OMWaNA trial aims to determine the effect of initiating KMC before stabilisation on mortality within seven days relative to standard care. Secondary objectives include exploring pathways for the intervention’s effects and assessing incremental costs and cost-effectiveness between arms. Methods We will conduct a four-centre, open-label, individually randomised, superiority trial in Uganda with two parallel groups: an intervention arm allocated to receive KMC and a control arm receiving standard care. We will enrol 2188 neonates (1094 per arm) for whom the indication for KMC is ‘uncertain’, defined as receiving ≥ 1 therapy (e.g. oxygen). Admitted singleton, twin and triplet neonates (triplet if demise before admission of ≥ 1 baby) weighing ≥ 700–≤ 2000 g and aged ≥ 1– Discussion The OMWaNA trial aims to assess the effectiveness of KMC in reducing mortality among neonates before stabilisation, a vulnerable population for whom its benefits are uncertain. The trial will improve understanding of pathways underlying the intervention’s effects and will be among the first to rigorously compare the incremental cost and cost-effectiveness of KMC relative to standard care. The findings are expected to have broad applicability to hospitals in sub-Saharan Africa and southern Asia, where three-quarters of global newborn deaths occur, as well as important policy and programme implications. Trial registration ClinicalTrials.gov, NCT02811432. Registered on 23 June 2016.

IntroductionGlobally, around 30% of ever-partnered women have experienced physical and/or sexual intimate partner violence (IPV) during their lifetime. To date, most research into causes and prevention of IPV involves surveys of women, with little research into risk-factors for male perpetration. This paper describes a survey of male partners of women participating in the MAISHA cluster randomised trial (CRT) of an IPV prevention intervention, in Mwanza City, Tanzania. Using linked couples' data, we explore man-, woman-, and relationship-/household-level factors associated with physical and sexual IPV.MethodsWomen were interviewed at baseline and 29-months follow-up. At follow-up, women were asked for consent to invite their partner to participate in the male survey. We describe response rates for the women's follow-up and male partners' surveys, and identify factors associated with women's consent to approach partners. Multivariate logistic regression was used to explore factors associated with women's past-year experiences of physical and sexual IPV.Results512 (65%) partnered women consented for the partner to be approached, higher among intervention than control women. 425 (83%) male partners were interviewed. Women consenting were disproportionately likely to be in longer-term relationships. Past-year IPV was associated with lower consent among control women, but greater consent in the intervention arm. Factors associated with increased odds of physical IPV were women's childhood experiences of abuse, young age, women's lower income and women's attitudes justifying IPV. Sexual IPV was associated with women's childhood experiences of abuse, young age, educational disparity within couple, men's alcohol use and women's poor mental health.ConclusionsWe successfully conducted a survey of male partners with the full consent of women trial participants. The breadth of factors associated with IPV demonstrates the need for IPV prevention interventions to work with women and men, and specifically couples. Interventions should address risk-factors for both physical and sexual IPV.

Background: The burden of kidney disease in sub-Saharan Africa is currently poorly understood. Very limited monitoring and treatment is available for people affected. The association with other diseases and with mortality is unknown in this setting. We sought to determine the association between kidney function and subsequent all-cause mortality. Methods: In a general population cohort with detailed measurement of health-related parameters in rural Uganda, we estimated the baseline glomerular filtration rate (GFR) between 2011-2014 in 5,678 participants. We followed participants up to March 2019 with regular ascertainment of mortality and migration. Using multivariable cox regression, we determined associations between baseline eGFR and mortality. Findings: The median age of the participants at baseline was 36 years (IQR 24-50), 60·7% were female, 14·6% hypertensive, 9·7% HIV-positive and 1·8% diabetic. We registered 140 deaths with a median follow-up of 5·0 years. Adjusting for age and sex, HIV, hypertension, diabetes, BMI, marital status, and alcohol and tobacco use participants with eGFR ≤45 mls/min/1·73m2 had six-fold higher mortality compared to those with eGFR ≥90mls/min/1·73m2(HR 6·12 (95% CI 2·27-16·45)) with strong evidence of a linear trend for risk of mortality as renal function declined (P