Associations between extreme weather events,mobility,and resource insecurities with HIV vulnerabilities among older adults in Moshi,Tanzania: Cross-sectional findings

Abstract

Background

Environmental and social hazards shape HIV vulnerabilities in Sub-Saharan Africa. Although older adults (>55) have an HIV prevalence higher than the national average in Tanzania, they are understudied in HIV research. To address this knowledge gap, we examined associations between extreme weather event exposure, mobility, resource insecurities, and HIV vulnerabilities among older adults in Moshi, Tanzania.

Methods

We conducted a cross-sectional survey in Moshi with adults aged ≥50 randomly sampled from the Prospective Urban Rural Epidemiology cohort. We conducted multivariable linear and logistic regression analyses to examine associations between environmental (past-year extreme weather events; recent [past 6- and 1-month] seasonal/weather-related mobility) and social (food, water, and/or sanitation insecurity) hazards, protective factors (social support, resilience), and HIV vulnerabilities (condom use self-efficacy; sexual relationship power; lifetime intimate partner violence). Models were adjusted for age, gender, education, and relationship status.

Results

Among participants (n = 250; mean age: 60.6 years, SD = 11.1; 72.8% women), over half (56.0%) reported >1 past-year extreme weather. Past-year extreme weather exposure (adjusted beta [aβ] = −1.09, 95% Confidence Interval [CI]: −2.08 to −0.10), past-month mobility (aβ = −2.25, 95%CI: −3.45 to −1.06), past 6-month mobility (aβ = −1.83, 95% CI: −3.17 to −0.48), and low food security (vs high/marginal) (aβ = −0.94, 95% CI: −1.72 to −0.15) were associated with lower condom use self-efficacy. Social support (aβ = 0.11, 95% CI: 0.06- 0.16) and resilience (aβ = 0.28, 95% CI: 0.12-0.44) were associated with increased condom use self-efficacy. Past-month (aβ = −5.03, 95% CI: −7.04 to −3.02) and 6-month (β = −2.59, 95% CI: −4.72 to −0.48) mobility were associated with lower sexual relationship power. Past-month mobility (aOR = 12.31, 95% CI: 2.67–56.80) and sanitation insecurity (aOR = 1.20, 95% CI: 1.10–1.32) were associated with higher intimate partner violence odds.

Conclusions

Extreme weather event exposure, seasonal/weather-related mobility, and resource insecurities were associated with HIV vulnerabilities among older adults in Moshi. HIV programs in climate-affected contexts can include older populations and integrate social and environmental hazards.

Keywords

older adults sexual health extreme weather food insecurity mobility sexual relationship power

Introduction

Extreme weather events directly and indirectly impact HIV vulnerabilities.¹ In Sub-Saharan Africa, for instance, extreme weather events such as droughts are associated with higher HIV prevalence and poorer care outcomes.² Tanzania ranks among the 25% most climate vulnerable countries globally.³ Although HIV risks are growing among older adults in Sub-Saharan Africa,⁴ little is known about how extreme weather events may shape HIV vulnerabilities in this population, including in Tanzania. The concept of HIV vulnerability is aligned with structural approaches to HIV prevention that emphasize the ways in which HIV exposure is socially and structurally produced, and shaped by environmental stressors, resource insecurity, and gendered power relations, rather than solely focusing on individual-level sexual practices.^5,6 The nexus of extreme weather, resource insecurity, and HIV vulnerability is understudied with older adults.

Extreme weather events may influence HIV vulnerabilities via complex pathways, including through heightening food insecurity (referring to constrained availability of and access to food) due to reduced agricultural yield, and reducing water and food security, including limiting access to adequate, reliable, and safe water and sanitation resources.¹ These resource scarcities in turn are associated with a range of relational-level HIV vulnerabilities,^1,2 which refer to interpersonal dynamics within sexual relationships that shape risk of HIV exposure (e.g., the ability to negotiate condom use, inequitable gender norms). Some of these relational-level vulnerabilities include reduced condom use efficacy, lower sexual relationship power,⁷ and increased intimate partner violence (IPV).⁸ Extreme weather events also increase short and long-term migration, including among older adults,⁹ which itself is linked with higher HIV prevalence and elevated HIV vulnerabilities, including inconsistent condom use, increased transactional sex,¹⁰ alongside heightened exposure to sexual exploitation, IPV, and changes in sexual networks.¹¹

These pathways from extreme weather events to HIV vulnerabilities are understudied among older adults, as HIV prevention and risk assessments often prioritize younger age groups. This contributes to lower perceived risk, inconsistent condom use, and delayed HIV testing and diagnosis among older populations. Stigma further constrains disclosure and HIV prevention and care engagement among older adults in Sub-Saharan Africa.⁴ Indeed, older adults remain underrepresented in research on extreme weather events and HIV in Tanzania,⁴ and at large, despite significant increases in HIV among middle-aged and older adults.⁴ In 2023, the highest HIV prevalence in Tanzania was observed among adults 45–54, with prevalence remaining above the national average among those aged 55–64.¹² Older adults may prioritize basic needs above HIV care, and financial and logistic barriers to accessing HIV and other sexual health services may be exacerbated by extreme weather event-related displacement and internal migration.¹³ Older women may face additional vulnerabilities, as widowhood increases with age and is associated with devalued social status and economic insecurity.¹⁴ In fact, in Sub-Saharan Africa, widowhood is linked with increased transactional sex, forced sex, and migration to urban areas due to economic vulnerability.⁴

Research has increasingly signaled the importance of an ecosocial approach¹⁵ that considers the role of both social (e.g. poverty) and environmental (e.g. extreme weather events) hazards in shaping health outcomes, such as HIV vulnerabilities.^1,2 This remains understudied, however, with older adults. To address these knowledge gaps, we examined associations between extreme weather event exposure, weather-related and seasonal mobility, and resource insecurities with HIV vulnerabilities among older adults in Moshi, Tanzania.

Materials and methods

Study design

We conducted a community-based cross-sectional survey in Moshi, Tanzania (March-November 2024). In Kilimanjaro region, Moshi has a tropical wet-dry climate that is increasingly characterized by extreme weather events. This study utilized data from the Prospective Urban Rural Epidemiology (PURE) cohort. The PURE study is an ongoing multinational cohort survey that has enrolled more than 200,000 adults aged 35–70 years of age at baseline (2003) from both urban and rural communities in 27 low-, middle-, and high-income countries, with the purpose of examining how modernization, urbanization, and globalization impact health outcomes.^16–18 The current study focuses specifically on a random sample of n = 250 participants drawn from the PURE study’s larger cohort of n = 2047 in Moshi, Tanzania. PURE Tanzania collects HIV status as a self-reported health outcome in their annual survey. The 2025 self-reported HIV prevalence in PURE-Tanzania was 2.24% (46/2047; 2.26% among women, and 2.22% among men). Recruitment was facilitated by PURE research assistants who administered tablet-based surveys in Swahili.

Measures

Informed by an ecosocial approach,¹⁵ we examined both environmental (including extreme weather event exposure) and social (including resource insecurity) factors associated with HIV vulnerabilities, in addition to protective factors.

HIV vulnerability outcomes

Condom use self-efficacy was measured using the five-item condom use self-efficacy scale (CUSES) (score range: 5–20)¹⁹ (Cronbach’s α = 0.91). Sexual relationship power was measured using the eight-item relationship control subscale (Cronbach’s α = 0.90) of the sexual relationship power scale (SRPS).²⁰ Lifetime intimate partner violence (IPV) was measured using six items adapted from the WHO Multi-Country Study on Women’s Health and Domestic violence (Cronbach’s α = 0.90).²¹ IPV was dichotomized based on responses to six items that examined lifetime emotional, physical, sexual, and controlling violence from an intimate partner, with an additional item added to reflect technology facilitated abuse. Participants reporting any of the IPV exposures were classified as having experienced lifetime IPV (1), otherwise were classified as not experiencing IPV (0).

Exposure variables

Resource insecurities were captured using standardized tools: water insecurity (12-item Household Water Insecurity Experiences [HWISE]; ≥12 = water insecure, Cronbach’s α = 0.85),²² food insecurity (6-item Household Food Security Survey Module [HFSSM]; categorized as high/marginal, low, or very low food security, Cronbach’s α = 0.86),²³ and sanitation insecurity (10-item scale, past 30 days, Cronbach’s α = 0.88).²⁴ Exposure to extreme weather events was assessed based on the question: “In the last year what have you experienced with regard to weather?” with multiple options (Table 1), including flooding and drought. Responses were categorized into three groups: no extreme weather event, one extreme weather event, and multiple extreme weather events. This measure has been validated in other research on extreme weather events and HIV vulnerabilities.^25,26 Seasonal/weather-related mobility was assessed using the question: “In the last 6 months, have you travelled to manage the effects of the season or weather?”^27,28 Responses included: no; yes (past month); yes (past 6 months).

Table 1.

Sociodemographic, extreme weather event, resource insecurity, and mobility characteristics of older adult participants in Moshi, Tanzania (n = 250).

Characteristics	Frequency (n, %)	Woman	Man	p-value
Socio-demographic variables
Gender
Cisgender women	182 (72.8%)
Cisgender men	68 (27.2%)
Age	60.6 (11.1)	60.2 (11.3)	61.5 (10.8)	0.4442
Education				0.224
Less than secondary	223 (89.2%)	165 (90.7%)	58 (85.3%)
Secondary completed & higher	27 (10.8%)	17 (9.3%)	10 (14.7%)
Employment				0.164
Unemployed	239 (95.6%)	176 (96.7%)	63 (92.6%)
Employed	11 (4.4%)	6 (3.3%)	5 (7.4%)
Relationship				<0.001
Married/Dating	161 (64.4%)	100 (55.2%)	61 (89.7%)
No current partner	69 (27.6%)	65 (35.9%)	4 (5.9%)
Multiple partners/polyamorous	1 (0.4%)
Separated/Widow/Widowed	19 (7.6%)	16 (8.8%)	3 (4.4%)
Have children (yes)	247 (98.8%)	180 (98.9%)	67 (98.5%)	0.810
HIV serostatus (self-report)				0.803
HIV negative	190 (76.3%)	139 (76.8%)	51 (75.0%)
Living with HIV	8 (3.2%)	5 (2.8%)	3 (4.4%)
Don’t know status	51 (20.5%)	14 (20.6%)	51 (20.5%)
Resource insecurity
Water insecurity score, mean (SD)	2.8 (4.5)			0.213
Insecure	15 (6.0%)	13 (7.1%)	2 (2.9%)
Secure	235 (94.0%)	169 (92.9%)	66 (97.1%)
Food insecurity score^{n = 8}, mean (SD)	2.7 (2.2)			0.278
High or marginal food security (0–1)	90 (37.2%)	61 (34.3%)	29 (45.3%)
Low food security (2–4)	82 (33.9%)	64 (36.0%)	18 (28.1%)
Very low food security (5–6)	70 (28.9%)	53 (29.7%)	17 (26.6%)
Sanitation insecurity (mean. SD)	13.2 (3.3)	13.69 (3.41)	11.82 (2.56)	0.0001
Extreme weather event-related variables
Extreme weather events in the past year^a				0.058
None	50 (20.0%)	43 (23.6%)	7 (10.3%)
One	60 (24.0%)	43 (23.6%)	17 (25.0%)
More than one	140 (56.0%)	96 (52.8%)	44 (64.7%)
Mobility: In the last 6 months, have you travelled to manage the effects of the season or weather?				0.942
Yes: In the last 1 month	9 (3.6%)	7 (3.8%)	2 (2.9%)
Yes: In the last 6 months	37 (14.8%)	27 (14.8%)	10 (14.7%)
No	204 (81.6%)	148 (81.3%)	56 (82.4%)
Study outcome variables
Lifetime intimate partner violence				0.488
No	136 (58.9%)	96 (57.5%)	40 (62.5%)
Yes	95 (41.1%)	71 (42.5%)	24 (37.5%)
Sexual relationship power (mean [SD])	15.04 (3.96)	13.61 (2.98)	17.35 (4.28)	<0.001
Condom use self-efficacy (mean [SD])	14.15 (2.63)	13.97 (2.79)	14.62 (2.07)	0.0841

ⁿMissing case

^aExtreme weather event options: extreme rain/flooding, changes in expected rain patterns in a season, changes in expected temperature (heat, cold) in a season, drought, extreme heat, extreme wind, extreme cold, fire (home fire, wildfire), storm (hurricane), landslide, earthquake. SD: Standard Deviation. Bold text refers to a significant p-value (p<0.05).

Protective factors included resilience (4-item adapted Response to Stressful Experiences Scale²⁹ [RSES-4]; Cronbach’s α = 0.73) and social support (12-item Multidimensional Scale of Perceived Social Support³⁰ [MSPSS], Cronbach’s α = 0.87).

Socio-demographic variables included age (continuous), gender (cisgender woman vs cisgender man), education (secondary + vs less), relationship status (partnered, unpartnered, separated/widowed), employment (employed vs unemployed), HIV serostatus (self-reported), and parenthood (yes vs no).

Statistical analysis

We first conducted descriptive statistics, including calculating means and standard deviation for continuous variables, and frequencies and percentages for categorical variables, to summarize sociodemographic characteristics, resource insecurity, and extreme weather event exposure. Group comparisons were assessed using chi-square tests for categorical variables and independent t-tests for continuous variables. Multivariable linear regression was used to examine associations between participant characteristics and condom use self-efficacy and sexual relationship power, while multivariable logistic regression was applied for IPV. Variables with p < 0.005 in bivariate analyses were included in multivariable models, which were adjusted for age, gender, education, and relationship status to control for potential confounding. Assumptions for linear regression (linearity, homoscedasticity, and normality of residuals) were assessed and met. Results are presented as adjusted beta coefficients (aβ) for linear models and adjusted odds ratios (aOR) for logistic models, each with 95% confidence intervals (CIs). G*Power 3.1^31,32 indicates that a sample size of 194 participants was required to detect a medium effect size (f² = 0.15, 14 predictors, α = 0.05, power = 0.95). Statistical significance was determined at the p < 0.05 level. All analyses were conducted using Stata SE version 18.0 (STATA Corp., Texas, USA).

Ethical considerations

Research ethics board approvals were obtained from the University of Toronto and The United Republic of Tanzania. Participants were compensated the equivalent of $8 USD for their time. All participants provided written voluntary consent to participate in the study.

Results

Socio-demographic characteristics (n = 250; mean age: 60.6 years, standard deviation [SD] = 11.1; cisgender women: n = 182, 72.8%) are reported in Table 1. Two-thirds of participants (n = 190, 76.3%) self-reported an HIV-negative status, 3.2% (n = 8) self-reported being HIV-positive, and one-fifth (n = 51) reported they did not know their HIV serostatus. Most participants reported water security (94.0%). Only 37.2%, however, reported high/marginal food security, while 33.9% reported low food security, and 28.9% had very low food security. More than half (56.0%) reported experiencing more than one extreme weather event in the past year, 24.0% reported one past-year extreme weather event, and 20.0% reported none. Nearly one-fifth reported recent seasonal or weather-related mobility, with 14.8% reporting past 6-months travel and 3.6% past month travel.

Reported in Table 2, in adjusted analyses, compared to those who were partnered, participants with no current partner (adjusted beta [aβ] = −0.84, 95% Confidence Interval [CI]: −1.62 to −0.06) or who were separated/widowed/divorced (aβ = −2.15, 95% CI: −3.39 to −0.90) had lower condom use self-efficacy. Low food security (vs high/marginal) was associated with lower condom use self-efficacy (aβ = −0.94, 95% CI: −1.72 to −0.15). Exposure to one past-year extreme weather event (aβ = −1.09, 95% CI: −2.08 to −0.10), past 1-month weather/season-related travel (aβ = −2.25, 95% CI: −3.45 to −1.06), and past 6-month weather/season-related travel (aβ = −1.83, 95% CI: −3.17 to −0.48) were associated with lower condom use self-efficacy. Higher social support (β = 0.11, 95% CI: 0.06 to 0.16) and resilience (aβ = 0.28, 95% CI: 0.12 to 0.44) were positively associated with condom use self-efficacy.

Table 2.

Multivariable linear and logistic regression of factors associated with sexual relationship power, lifetime intimate partner violence, and condom use self-efficacy among older adult participants in Moshi, Tanzania (n = 250).

Variable	Sexual relationship power (linear regression)				Lifetime intimate partner violence (logistic regression)				Condom use self-efficacy (linear regression)
Variable	Unadjusted beta coefficient (β) (95% CI)	p-value	Adjusted^a β (95% CI)	p-value	Unadjusted odds ratio (OR) (95% CI)	p-value	Adjusted^a odds ratio (OR) (95% CI)	p-value	Unadjusted β (95% CI)	p-value	Adjusted^a β (95% CI)	p-value
Socio-demographic variables
Age	0.03 (−0.03, 0.09)	0.292	−0.01 (−0.06, 0.05)	0.854	0.97 (0.94, 0.99)	0.008	0.96 (0.94, 0.99)	0.004	−0.02 (−0.05, 0.01)	0.124	−0.01 (−0.04, 0.02)	0.414
Gender
Cisgender man	Ref				Ref				Ref
Cisgender woman	−3.74 (−4.94, −2.53)	<0.001	−3.87 (−5.11, −2.62)	<0.001	1.23 (0.68, 2.23)	0.488			−0.64 (−1.38, 0.09)	0.084	−0.28 (−1.04, 0.48)	0.463
Education
Less than secondary	Ref		Ref		Ref				Ref
Secondary and higher	1.06 (−0.82, 2.95)	0.267	0.92 (−0.77, 2.60)	0.285	0.91 (0.38, 2.20)	0.838			0.96 (−0.09, 2.01)	0.074	0.62 (−0.42, 1.65)	0.243
Relationship status
Married/Dating	Ref		Ref		Ref				Ref
No current partner	−1.59 (−7.18, 4.00)	0.576	0.01 (−4.98, 4.99)	0.998	0.75 (0.41, 1.37)	0.350	0.88 (0.45, 1.72)	0.699	−1.03 (−1.75, −0.31)	0.005	−0.84 (−1.62, −0.06)	0.035
Separated/Widow/Widowed	−4.09 (−11.96, 3.79)	0.307	−6.42 (−13.52, 0.68)	0.076	4.76 (1.26, 18.00)	0.021	6.33 (1.57, 25.53)	0.010	−2.35 (−3.56, −1.13)	<0.001	−2.15 (−3.39, −0.90)	0.001
Employment
Unemployed vs employed	−0.72 (−3.29, 1.86)	0.584			0.83 (0.25, 2.80)	0.765			−0.32 (−1.92, 1.28)	0.693
Resource insecurity variables
Water insecure (Vs secure)	−2.30 (−4.85, 0.25)	0.077			2.27 (0.78, 6.60)	0.133			−0.94 (−2.31, 0.44)	0.181
Food insecurity
High or marginal food security	Ref				Ref				Ref
Low food security	0.20 (−1.37, 1.77)	0.798			1.55 (0.82, 2.94)	0.177			−1.00 (−1.79, −0.22)	0.013	−0.94 (−1.72, −0.15)	0.019
Very low food security	−0.01 (-1.76, 1.74)	0.990			1.84 (0.94, 3.60)	0.073			−0.30 (−1.13, 0.52)	0.469	−0.26 (−1.08, 0.55)	0.522
Higher sanitation insecurity	−0.27 (−0.46, −0.08)	0.006	−0.10 (−0.28, 0.09)	0.298	1.21 (1.11, 1.32)	<0.001	1.20 (1.10, 1.32)	< 0.001	−0.11 (−0.21, −0.01)	0.025	−0.09 (−0.19, 0.01)	0.095
Extreme weather event-related variables
Extreme weather events in the past year^b
None	Ref				Ref
One	−0.97 (−2.92, 0.98)	0.328			2.19 (1.00, 4.81)	0.049	2.28 (0.97, 5.34)	0.057	−0.99 (−1.98, −0.01)	0.048	−1.09 (−2.08, −0.10)	0.031
Multiple	0.02 (−1.72, 1.75)	0.985			1.43 (0.71, 2.86)	0.317	1.46 (0.69, 3.08)	0.324	−0.34 (−1.19, 0.50)	0.425	−0.36 (−1.21, 0.50)	0.411
Mobility (travel to manage effects of the season or weather)
No	Ref								Ref
Yes: In the last 1 month	−4.99 (−7.32, −2.66)	<0.001	−5.03 (−7.04, −3.02)	<0.001	13.23 (2.96, 59.14)	0.001	12.31 (2.67, 56.80)	0.001	−2.36 (−3.59, −1.14)	<0.001	−2.25 (−3.45, −1.06)	<0.001
Yes: In the last 6 months	−1.64 (−4.07, 0.790	0.186	−2.59 (−4.72, −0.48)	0.017	0.66 (0.20, 2.18)	0.497	0.69 (0.20, 2.44)	0.563	−1.77 (−3.15, −0.39)	0.012	−1.83 (−3.17, −0.48)	0.008
Protective factors
Social support	0.05 (−0.07, 0.17)	0.390			1.01 (0.97, 1.06)	0.509			0.11 (0.06, 0.16)	<0.001	0.11 (0.06, 0.16)	<0.001
Resilience	−0.10 (−0.45, 0.25)	0.585			1.11 (0.96, 1.29)	0.168			0.24 (0.07, 0.40)	0.005	0.28 (0.12, 0.44)	0.001

^aAdjusted for age, gender, education, relationship status.

^bExtreme weather event options: extreme rain/flooding, changes in expected rain patterns in a season, changes in expected temperature (heat, cold) in a season, drought, extreme heat, extreme wind, extreme cold, fire (home fire, wildfire), storm (hurricane), landslide, earthquake. Bold text refers to a significant p-value (p<0.05).

In adjusted analyses (Table 2), women had significantly lower sexual relationship power scores compared to men (aβ = −3.87, 95% CI: −5.11 to −2.62). Participants noting past-month mobility (aβ = −5.03, 95% CI: −7.04 to −3.02) and past-6-month mobility (aβ = −2.59, 95% CI: −4.72 to −0.48) reported lower sexual relationship power.

Older age was associated with reduced odds of lifetime IPV (adjusted Odds Ratio [aOR] = 0.96, 95% CI: 0.94–0.99). Compared to partnered participants, those who were separated/widowed/divorced had significantly higher odds of lifetime IPV (aOR = 6.33, 95% CI: 1.57–25.53). Sanitation insecurity (aOR = 1.20, 95% CI: 1.10–1.32) and past month weather/season-related mobility (aOR = 12.31, 95% CI: 2.67–56.80) were also associated with higher odds of lifetime IPV (See Table 2).

Discussion

In this cross-sectional survey of older adults in Moshi, exposure to multiple past-year extreme weather events, recent mobility related to weather or season, and resource insecurity (i.e., food, water, sanitation) were associated with a range of HIV vulnerabilities, including lower condom use self-efficacy, reduced sexual relationship power, and a higher likelihood of lifetime IPV. This signals the importance of including older adults in HIV and climate change related research—where they are often overlooked—and the relevance of an ecosocial approach that considers the role of social and environmental hazards in shaping older adults’ HIV vulnerabilities.¹⁵

Our findings expand on prior research. We found seasonal and weather-related mobility were linked with reduced condom use self-efficacy and sexual relationship power, aligning with research with younger populations that document the complex ways that climate shocks disrupt livelihoods, social networks, and sexual health access, and how this reduces sexual agency.^1,33,34 These effects could be amplified by ageism in sexual health programs³⁵ that results in lower perceived HIV risk,³⁶ and reduced access to age-tailored services. Recent weather and seasonal mobility, known drivers of HIV vulnerability,²⁷ may harm older adults’ sexual wellbeing and increase HIV acquisition risks across the life course.

Resource insecurities were also associated with HIV vulnerabilities. Food insecurity was associated with reduced condom use self-efficacy, corroborating past research on the ways through which unmet survival needs can reduce sexual negotiation power.⁷ Sanitation insecurity and weather/seasonal mobility were associated with lifetime IPV, indicating that environmental stressors may aggravate household tensions.^1,8 Social support and resilience were positively associated with condom use self-efficacy, suggesting that strengthening individual and collective coping for environmental stressors^37,38 may advance sexual health.

There are study limitations. First, we randomly sampled from the PURE cohort that may not be generalizable to all older adults in Moshi, as PURE participants may be more socially connected. Second, HIV prevalence estimates for PURE Tanzania were based on self-report and may be subject to underreporting due to stigma, limited access to testing, or lack of awareness of HIV serostatus. Third, we included a lifetime measure of IPV; assessing IPV in more recent timeframes could better identify linkages between environmental and social factors and IPV risks. Fourth, the cross-sectional design precludes ascertaining causality. Fifth, self-reported extreme weather event exposure may be subject to recall bias and variability in interpretation of what constitutes an ‘extreme’ event, potentially resulting in misclassification. This may have led to over- or under-estimation of exposure. In addition, categorization of events does not capture differences in severity or duration. Future research could strengthen measurement through linkage with meteorological or geospatial data. Future longitudinal, geospatial and mixed-methods research is needed to identify causal mechanistic pathways between extreme weather events and clinically validated HIV and other sexually transmitted infections, including among older adults who have often been overlooked in this research. In turn, this can inform further research on climate-informed sexual health prevention strategies (e.g., HIV self-testing, over the counter postexposure prophylaxis) and interventions (e.g., long-acting PrEP, mobile pharmacies and health services).³³

Together findings highlight the need to develop climate-informed sexual health programs with and for older adults in Moshi. Integrating screening for extreme weather event exposure, resource insecurities (food, water), and violence, and building older adult tailored services within HIV programming offer a promising way forward. As extreme weather events are increasing in intensity and frequency, integrated programs can mitigate the effects of extreme weather exposure, mobility, and resource insecurity-related stressors to advance HIV prevention and sexual health equity across the life course.

Footnotes

Acknowledgements

We would like to acknowledge all of the participants, research team, and support from Pamoja Tunaweza Women’s Centre/Wema Health Innovation Tanzania.

ORCID iDs

Carmen H. Logie

Zerihun Admassu

Ethical considerations

REB approvals were obtained from University of Toronto (#41615) and The United Republic of Tanzania (NIMR/HQ/R.8c/Vol.1/2538).

Author contributions

CHL led writing, study design and conceptualization, contributed to data analysis, conceptualized manuscript, and acquired funding. AM and AP significantly contributed to writing and editing. KY and NW supported implementation and coordination, data management, analysis, and contributed to writing, editing and reviewing. FM supported implementation, coordination, data management and contributed to writing, editing and reviewing. HR, AK, OU, were significantly involved in study implementation and data collection, and contributed to editing and reviewing. ZA contributed to study design, data management, significantly contributed to writing, and led the data analysis.

Funding

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study is funded by the Canada Research Chairs Program (Logie Tier 2). Additional funding was received from the Canadian Institutes of Health Research (Project Grant: 496342).

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Data Availability Statement

Data are available upon reasonable request. The research ethics board approvals restrict data sharing on a public repository. Requests for anonymized data may be made to the corresponding author.*

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