Exploring COVID-19 vaccine hesitancy and uptake in Nairobi’s urban informal settlements: an unsupervised machine learning analysis of a longitudinal prospective cohort study from 2021 to 2022

Objectives To illustrate the utility of unsupervised machine learning compared with traditional methods of analysis by identifying archetypes within the population that may be more or less likely to get the COVID-19 vaccine.Design A longitudinal prospective cohort study (n=2009 households) with recurring phone surveys from 2020 to 2022 to assess COVID-19 knowledge, attitudes and practices. Vaccine questions were added in 2021 (n=1117) and 2022 (n=1121) rounds.Setting Five informal settlements in Nairobi, Kenya.Participants Individuals from 2009 households included.Outcome measures and analysis Respondents were asked about COVID-19 vaccine acceptance (February 2021) and vaccine uptake (March 2022). Three distinct clusters were estimated using K-Means clustering and analysed against vaccine acceptance and vaccine uptake outcomes using regression forest analysis.Results Despite higher educational attainment and fewer concerns regarding the pandemic, young adults (cluster 3) were less likely to intend to get the vaccine compared with cluster 1 (41.5% vs 55.3%, respectively; p<0.01). Despite believing certain COVID-19 myths, older adults with larger households and more fears regarding economic impacts of the pandemic (cluster 1) were more likely to ultimately to get vaccinated than cluster 3 (78% vs 66.4%; p<0.01), potentially due to employment requirements. Middle-aged women who are married or divorced and reported higher risk of gender-based violence in the home (cluster 2) were more likely than young adults (cluster 3) to report wanting to get the vaccine (50.5% vs 41.5%; p=0.014) but not more likely to have gotten it (69.3% vs 66.4%; p=0.41), indicating potential gaps in access and broader need for social support for this group.Conclusions Findings suggest this methodology can be a useful tool to characterise populations, with utility for improving targeted policy, programmes and behavioural messaging to promote uptake of healthy behaviours and ensure equitable distribution of prevention measures

Household Contact Screening and Yield of Tuberculosis Cases-A Clinic Based Study in Chennai, South India.

BACKGROUND:Contact investigation is an active case finding strategy to increase detection of Tuberculosis (TB) and a key component of TB control programs. The household contacts are at a higher risk of exposure than members of the general population. The information on the value and yield of household contact screening and the approaches used in high incidence settings like India is limited. OBJECTIVE:To evaluate the yield of active case finding in household contacts of newly diagnosed smear positive TB patients and the factors associated with increased yield. METHOD:Retrospective record review of the household contacts of newly diagnosed sputum smear positive patients (index case) enrolled in a clinical trial at National Institute of Research in Tuberculosis, Chennai during the period 2007-2014. A sequential screening algorithm with chest x-ray followed by symptom screen was employed to identify presumptive TB patients. RESULTS:643 household contacts of 280 index TB patients were identified out of which 544 (85%) consented for screening. 71/544 (13%) patients had an abnormal chest radiograph and out of them 70% were symptomatic. A total of 29/544 (5.3%) contacts were found to have TB among whom 23/29 (79%) were sputum smear positive. The number needed to screen (NNS) to identify a new TB case among all household contacts was 19 and among those with an abnormal CXR was 02. Age group > 44 years, male gender and siblings of the index case was associated with abnormal chest radiograph whereas age group between 15-44 was significantly associated with developing TB disease among household contacts. CONCLUSION:Active screening among household contacts is an effective way to improve TB case detection. The yield for new TB cases among contacts with abnormal x-ray was high in this study and the use of Chest X-rays in combination with symptom screen is recommended

Gendered economic, social and health effects of the COVID-19 pandemic and mitigation policies in Kenya: Evidence from a prospective cohort survey in Nairobi informal settlements

Objectives: COVID-19 may spread rapidly in densely populated urban informal settlements. Kenya swiftly implemented mitigation policies; we assess the economic, social and health-related harm disproportionately impacting women. Design: A prospective longitudinal cohort study with repeated mobile phone surveys in April, May and June 2020. Participants and setting: 2009 households across five informal settlements in Nairobi, sampled from two previously interviewed cohorts. Primary and secondary outcome measures: Outcomes include food insecurity, risk of household violence and forgoing necessary health services due to the pandemic. Gender-stratified linear probability regression models were constructed to determine the factors associated with these outcomes. Results: By May, more women than men reported adverse effects of COVID-19 mitigation policies on their lives. Women were 6 percentage points more likely to skip a meal versus men (coefficient: 0.055; 95% CI 0.016 to 0.094), and those who had completely lost their income were 15 percentage points more likely versus those employed (coefficient: 0.154; 95% CI 0.125 to 0.184) to skip a meal. Compared with men, women were 8 percentage points more likely to report increased risk of household violence (coefficient: 0.079; 95% CI 0.028 to 0.130) and 6 percentage points more likely to forgo necessary healthcare (coefficient: 0.056; 95% CI 0.037 to 0.076). Conclusions: The pandemic rapidly and disproportionately impacted the lives of women. As Kenya reopens, policymakers must deploy assistance to ensure women in urban informal settlements are able to return to work, and get healthcare and services they need to not lose progress on gender equity made to date

Socio-demographic and clinical characteristics of new sputum smear positive index cases (N = 280) in Chennai, India.

<p>Socio-demographic and clinical characteristics of new sputum smear positive index cases (N = 280) in Chennai, India.</p

Socio-demographic and clinical characteristics of house hold contacts of (N = 643) new sputum smear positive index cases in Chennai, India.

<p>Socio-demographic and clinical characteristics of house hold contacts of (N = 643) new sputum smear positive index cases in Chennai, India.</p

Factors associated with abnormal CXR and TB disease among the household contacts who had their CXR done (N = 544) in Chennai, India.

<p>Factors associated with abnormal CXR and TB disease among the household contacts who had their CXR done (N = 544) in Chennai, India.</p

Number of household contacts of TB index cases needed to screen (NNS) to identify one new case of TB/smear positive TB, Chennai, India.

<p>Number of household contacts of TB index cases needed to screen (NNS) to identify one new case of TB/smear positive TB, Chennai, India.</p