BACKGROUND: We sought to estimate SARS-CoV-2 antibody seroprevalence within representative samples of the Kenyan population during the third year of the COVID-19 pandemic and the second year of COVID-19 vaccine use. METHODS: We conducted cross-sectional serosurveys among randomly selected, age-stratified samples of Health and Demographic Surveillance System (HDSS) residents in Kilifi and Nairobi. Anti-spike (anti-S) immunoglobulin G (IgG) serostatus was measured using a validated in-house ELISA and antibody concentrations estimated with reference to the WHO International Standard for anti-SARS-CoV-2 immunoglobulin. RESULTS: HDSS residents were sampled in February-June 2022 (Kilifi HDSS N = 852; Nairobi Urban HDSS N = 851) and in August-December 2022 (N = 850 for both sites). Population-weighted coverage for ≥1 doses of COVID-19 vaccine were 11.1% (9.1-13.2%) among Kilifi HDSS residents by November 2022 and 34.2% (30.7-37.6%) among Nairobi Urban HDSS residents by December 2022. Population-weighted anti-S IgG seroprevalence among Kilifi HDSS residents increased from 69.1% (65.8-72.3%) by May 2022 to 77.4% (74.4-80.2%) by November 2022. Within the Nairobi Urban HDSS, seroprevalence by June 2022 was 88.5% (86.1-90.6%), comparable with seroprevalence by December 2022 (92.2%; 90.2-93.9%). For both surveys, seroprevalence was significantly lower among Kilifi HDSS residents than among Nairobi Urban HDSS residents, as were antibody concentrations (p < 0.001). CONCLUSION: More than 70% of Kilifi residents and 90% of Nairobi residents were seropositive for anti-S IgG by the end of 2022. There is a potential immunity gap in rural Kenya; implementation of interventions to improve COVID-19 vaccine uptake among sub-groups at increased risk of severe COVID-19 in rural settings is recommended.

Background Up-to-date SARS-CoV-2 antibody seroprevalence estimates are important for informing public health planning, including priorities for Coronavirus disease 2019 (COVID-19) vaccination programs. We sought to estimate infection- and vaccination-induced SARS-CoV-2 antibody seroprevalence within representative samples of the Kenyan population approximately two years into the COVID-19 pandemic and approximately one year after rollout of the national COVID-19 vaccination program. Methods We conducted cross-sectional serosurveys within random, age-stratified samples of Kilifi Health and Demographic Surveillance System (HDSS) and Nairobi Urban HDSS residents. Anti-spike (anti-S) immunoglobulin G (IgG) and anti-nucleoprotein (anti-N) IgG were measured using validated in-house ELISAs. Target-specific Bayesian population-weighted seroprevalence was calculated overall, by sex and by age, with adjustment for test performance as appropriate. Anti-S IgG concentrations were estimated with reference to the WHO International Standard (IS) for anti-SARS-CoV-2 immunoglobulin and their reverse cumulative distributions plotted. Results Between February and June 2022, 852 and 851 individuals within the Kilifi HDSS and the Nairobi Urban HDSS, respectively, were sampled. Only 11.0% (95% confidence interval [CI] 9.0-13.3) of all Kilifi HDSS participants and 33.4% (95%CI 30.2-36.6) of all Nairobi Urban HDSS participants had received any doses of COVID-19 vaccine. Population-weighted antiS IgG seroprevalence was 69.1% (95% credible interval [CrI] 65.8-72.3) within the Kilifi HDSS and 88.5% (95%CrI 86.1-90.6) within the Nairobi Urban HDSS. Among COVID-unvaccinated residents of the Kilifi HDSS and Nairobi Urban HDSS, it was 66.7% (95%CrI 63.3-70.0) and 85.3% (95%CrI 82.1-88.2), respectively. Population-weighted, test-adjusted anti-N IgG seroprevalence within the Kilifi HDSS was 53.5% (95%CrI 46.5-61.1) and 65.5% (95%CrI 56.0-75.6) within the Nairobi Urban HDSS. The prevalence of anti-N antibodies was similar in vaccinated and unvaccinated subgroups in both HDSS populations. Anti-S IgG concentrations were significantly lower among Kilifi HDSS residents than among Nairobi Urban HDSS residents (p< 0.001). Conclusions Approximately, 7 in 10 Kilifi residents and 9 in 10 Nairobi residents were seropositive for anti-S IgG by May 2022 and June 2022, respectively. Given COVID-19 vaccination coverage, anti-S IgG seropositivity among COVID-unvaccinated individuals, and anti-N IgG seroprevalence, population-level anti-S IgG seroprevalence was predominantly derived from infection. Interventions to improve COVID-19 vaccination uptake should be targeted to individuals in rural Kenya who are at high risk of severe COVID-19. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license.

OBJECTIVES: To estimate referral compliance and examine factors that influence decisions to comply with referral for newborn and maternal complications in Bosaso, Somalia. SETTING: Bosaso, Somalia, is a large port city that hosts a large proportion of internally displaced persons. The study was conducted at the only four primary health centres offering 24/7 delivery services and the only public referral hospital in Bosaso. PARTICIPANTS: All pregnant women who sought care at four primary centres and were referred to the hospital for maternal complications or mothers whose newborns were referred for neonatal complications were approached for enrolment from September to December 2019. In-depth interviews (IDIs) of 54 women and 14 healthcare workers (HCWs) were conducted. OUTCOME MEASURES: This study examined timely referral compliance from the primary centre to the hospital. IDIs were analysed for a priori themes investigating the decision-making process and experience of care for maternal and newborn referrals. RESULTS: Overall, 94% (n=51/54) of those who were referred, 39 maternal and 12 newborns, complied with the referral and arrived at the hospital within 24 hours. Of the three that did not comply, two delivered on the way, and one cited lack of money as the reason for noncompliance. Four themes emerged: trust in medical authority, cost of transportation and care, quality of care, and communications. The factors that facilitated compliance were the availability of transportation, family support, concern for health, and trust in medical authority. HCWs raised the importance of considering the maternal-newborn dyad throughout the referral process, and the need for official standard operating procedures for referrals including communications between the primary care and the hospital. CONCLUSIONS: High compliance for referral from primary to hospital care for maternal and newborn complications was observed in Bosaso, Somalia. Costs associated with transportation and care at the hospital need attention to motivate compliance.

BACKGROUND: There is substantial burden of seasonal influenza in Kenya, which led the government to consider introducing a national influenza vaccination programme. Given the cost implications of a nationwide programme, local economic evaluation data are needed to inform policy on the design and benefits of influenza vaccination. We set out to estimate the cost-effectiveness of seasonal influenza vaccination in Kenya. METHODS: We fitted an age-stratified dynamic transmission model to active surveillance data from patients with influenza from 2010 to 2018. Using a societal perspective, we developed a decision tree cost-effectiveness model and estimated the incremental cost-effectiveness ratio (ICER) per disability-adjusted life year (DALY) averted for three vaccine target groups: children 6-23 months (strategy I), 2-5 years (strategy II) and 6-14 years (strategy III) with either the Southern Hemisphere influenza vaccine (Strategy A) or Northern Hemisphere vaccine (Strategy B) or both (Strategy C: twice yearly vaccination campaigns, or Strategy D: year-round vaccination campaigns). We assessed cost-effectiveness by calculating incremental net monetary benefits (INMB) using a willingness-to-pay (WTP) threshold of 1-51% of the annual gross domestic product per capita ($17-$872). RESULTS: The mean number of infections across all ages was 2-15 million per year. When vaccination was well timed to influenza activity, the annual mean ICER per DALY averted for vaccinating children 6-23 months ranged between $749 and $1385 for strategy IA, $442 and $1877 for strategy IB, $678 and $4106 for strategy IC and $1147 and $7933 for strategy ID. For children 2-5 years, it ranged between $945 and $1573 for strategy IIA, $563 and $1869 for strategy IIB, $662 and $4085 for strategy IIC, and $1169 and $7897 for strategy IID. For children 6-14 years, it ranged between $923 and $3116 for strategy IIIA, $1005 and $2223 for strategy IIIB, $883 and $4727 for strategy IIIC and $1467 and $6813 for strategy IIID. Overall, no vaccination strategy was cost-effective at the minimum ($17) and median ($445) WTP thresholds. Vaccinating children 6-23 months once a year had the highest mean INMB value at $872 (WTP threshold upper limit); however, this strategy had very low probability of the highest net benefit. CONCLUSION: Vaccinating children 6-23 months once a year was the most favourable vaccination option; however, the strategy is unlikely to be cost-effective given the current WTP thresholds.

BACKGROUND: Increasingly, neonatal mortality is concentrated in settings of conflict and political instability. To promote evidence-based practices, an interagency collaboration developed the Newborn Health in Humanitarian Settings: Field Guide. The essential newborn care component of the Field Guide was operationalized with the use of an intervention package encompassing the training of health workers, newborn kit provisions and the installation of a newborn register. METHODS: We conducted a quasi-experimental prepost study to test the effectiveness of the intervention package on the composite outcome of essential newborn care from August 2016 to December 2018 in Bossaso, Somalia. Data from the observation of essential newborn care practices, evaluation of providers' knowledge and skills, postnatal interviews, and qualitative information were analyzed. Differences in two-proportion z-tests were used to estimate change in essential newborn care practices. A generalized estimating equation was applied to account for clustering of practice at the health facility level. RESULTS: Among the 690 pregnant women in labor who sought care at the health facilities, 89.9% (n = 620) were eligible for inclusion, 84.7% (n = 525) were enrolled, and newborn outcomes were ascertained in 79.8% (n = 419). Providers' knowledge improved from pre to posttraining, with a mean difference in score of + 11.9% (95% CI: 7.2, 16.6, p-value < 0.001) and from posttraining to 18-months after training with a mean difference of + 10.9% (95% CI: 4.7, 17.0, p-value < 0.001). The proportion of newborns who received two or more essential newborn care practices (skin-to-skin contact, early breastfeeding, and dry cord care) improved from 19.9% (95% CI: 4.9, 39.7) to 94.7% (95% CI: 87.7, 100.0). In the adjusted model that accounted for clustering at health facilities, the odds of receiving two or more essential newborn practices was 64.5 (95% CI: 15.8, 262.6, p-value < 0.001) postintervention compared to preintervention. Predischarge education offered to mothers on breastfeeding 16.5% (95% CI: 11.8, 21.1) vs 44.2% (95% CI: 38.2, 50.3) and newborn illness danger signs 9.1% (95% CI: 5.4, 12.7) vs 5.0% (95% CI: 2.4, 7.7) remained suboptimal. CONCLUSIONS: The intervention package was feasible and effective in improving essential newborn care. Knowledge and skills gained after training were mostly retained at the 18-month follow-up.

BACKGROUND: Clinical outcomes for patients with Kaposi's sarcoma (KS) using nonnucleoside reverse transcriptase inhibitor (NNRTI)-based highly active antiretroviral therapy (HAART) in resource-limited settings have not previously been described. METHODS: We evaluated HIV-infected patients aged ≥18 years, who initiated HAART in the Home-Based AIDS Care (HBAC) project in Tororo, Uganda, between May 2003 and February 2008 and were diagnosed with KS at baseline or during follow-up. We examined independent risk factors for having either prevalent or incident KS and risk factors for death among patients with KS. RESULTS: Of 1121 study subjects, 17 (1.5%) were diagnosed with prevalent KS and 18 (1.6%) with incident KS over a median of 56.1 months of follow-up. KS was associated with male sex [adjusted odds ratio (AOR) 2.41; 95% confidence interval (CI) 1.20-4.86] and baseline CD4 cell count < 50 cells/mcL (AOR 3.25; 95% CI 1.03-10.3). Eleven (65%) of 17 patients with prevalent KS and 13 (72%) of 18 patients with incident KS experienced complete regression (P = 0.137). Eighteen (64%) of 28 patients who remained on NNRTI-based HAART experienced regression of their KS and six (86%) of seven patients who were switched to protease inhibitor-containing HAART regimens had regression of their KS (P = 0.23). Mortality among those with KS was significantly associated with visceral disease (hazard ratio 19.22; 95% CI 2.42-152). CONCLUSION: Prevalent or incident KS was associated with 30% mortality. The resolution of KS lesions among individuals who initiated HAART with NNRTI-based regimens was similar to that found in studies using only protease inhibitor-based HAART.

BACKGROUND: Highly active antiretroviral therapy (HAART) drastically reduces mother-to-child transmission of HIV, but where breastfeeding is the only safe infant feeding option, HAART for the prevention of mother-to-child transmission needs to be evaluated in relation to both HIV transmission and infant mortality. DESIGN AND METHODS: One hundred and two > or = 18-year old women on HAART in rural Uganda who delivered one or more live infants between March 1, 2003 and January 1, 2007 were enrolled in a prospective study to assess HIV transmission and infant survival. All pregnant women were counseled to exclusively breastfeed for 3-6 months according to national guidelines at the time. Infants were followed-up for > or = 7 months and were offered HIV polymerase chain reaction testing quarterly from 6 weeks of age until > or = 6 weeks after complete weaning. RESULTS: Of 118 infants born during follow-up, 109 (92%) were breastfed. Median durations of exclusive and total breastfeeding were 4 months (interquartile range 3-6) and 5 months (interquartile range 3-7), respectively. None of the infants tested HIV polymerase chain reaction positive over follow-up but 16 infants died without a definitive HIV status at a median age of 2.6 months. In total, 23 (19%) infants died during follow-up at a median age of 3.7 months; 15 (65%) of whom with severe diarrhea and/or vomiting in the week preceding their death. In multivariate analysis, there was a 6-fold greater risk of death among infants breastfed for less than 6 months independent of maternal CD4 count closest to delivery, maternal marital status or maternal death (adjusted hazard ratio = 6.19; 95% confidence interval 1.41-27.0, P = 0.015). CONCLUSIONS: In resource-constrained settings, HIV-infected pregnant women should be assessed for HAART eligibility and treated as needed without delay, and should be encouraged to breastfeed their infants for at least 6 months.