Over half of malaria cases reported in the USA occur among people travelling to visit friends and relatives (VFRs), predominantly to West Africa. Few studies have queried VFR travellers directly on barriers to seeking pre-travel care. We aim to describe the knowledge, attitudes and practices of VFRs travelling to malaria-endemic countries from the USA. With these findings, we aim to design interventions to encourage preventive behaviours before and during travel. Sixteen focus groups were held in two US metropolitan areas with West African immigrant populations: Minneapolis-St. Paul, MN, and New York City, NY. A total of 172 people from 13 African countries participated. Focus group discussions were audio-recorded and transcribed, and modified grounded theory analysis was performed. Participants reviewed themes to verify intent of statements. Participants described the high cost of provider visits and chemoprophylaxis, challenges in advocating for themselves in healthcare settings and concerns about offending or inconveniencing hosts as barriers to malaria prevention. Cultural barriers to accessing pre-travel care included competing priorities when trip planning, such as purchasing gifts for family, travel logistics and safety concerns. When participants sought pre-travel care, most consulted their primary care provider. Participants expressed low confidence in US providers’ knowledge and training about malaria and other tropical diseases. Barriers to pre-travel care for VFR travellers are multifaceted and extend beyond their perception of disease risk. Only some barriers previously reported in anecdotal and qualitative literature were supported in our findings. Future interventions should be aimed at barriers identified by individual communities and involve primary and travel specialist healthcare providers. Additional work is needed to address systems-level barriers to accessing care and establishing community-based programs to support West African VFR traveller health.

Prior studies have reported lower effectiveness of XBB.1.5-adapted vaccines against hospitalization related to the Omicron JN.1 variant than the XBB variant. This study evaluated the effectiveness and durability of the BNT162b2 XBB.1.5-adapted vaccine against JN.1-related hospitalization during the 2023–2024 season in Europe. A test-negative case–control study was carried out in adults (≥18 y) hospitalized between 2 October 2023 and 2 April 2024 with severe acute respiratory infection (SARI) within the id.DRIVE partnership. This study included nine sites across Belgium, Germany, Italy, and Spain. Cases had a laboratory-confirmed JN.1 infection or a positive SARS-CoV-2 test with symptom onset during JN.1 predominance; controls had a negative SARS-CoV-2 test and symptom onset during JN.1 predominance. The primary objective was to estimate BNT162b2 XBB.1.5-adapted vaccine effectiveness (VE) against COVID-19 hospitalization. One case was matched with up to four controls, according to symptom onset date and site. Multivariable analyses were adjusted for symptom onset date, age, sex, and number of chronic conditions. Among 308 test-positive cases and 1117 test-negative controls, BNT162b2 XBB.1.5-adapted VE against hospitalization compared to no vaccination this season was 53.8% (95% CI 38.4–65.4) after a median of 63 days following vaccination. Protection was sustained through five months; VE was 52.2% (95% CI 41.3–61.1) 2 to <4 weeks after vaccination, 48.9% (95% CI 17.9–68.2) at 4 to <8 weeks, and ranged from 54.6% to 59.5% at 4-week intervals from 8 to <22 weeks. BNT162b2 XBB.1.5-adapted vaccine provided protection against JN.1-related hospitalization, regardless of prior vaccination history, with no evidence of waning through five months. These data support yearly vaccination against COVID-19 to prevent severe illness during the respiratory virus season. 10.13039/100004319 Pfizer .

Despite achievements in the reduction of malaria globally, imported malaria cases to the United States by returning international travelers continue to increase. Immigrants to the United States from sub-Saharan Africa (SSA) who then travel back to their homelands to visit friends and relatives (VFRs) experience a disproportionate burden of malaria illness. Various studies have explored barriers to malaria prevention among VFRs and non-VFRs–travelers to the same destinations with other purpose for travel–but few employed robust epidemiologic study designs or performed comparative analyses of these two groups. To better quantify the key barriers that VFRs face to implement effective malaria prevention measures, we conducted a comprehensive community-based, cross-sectional, survey to identify differences in malaria prevention knowledge, attitudes, and practices (KAP) among VFRs and others traveling to Africa and describe the differences between VFRs and other types of international travelers. Three distinct populations of travelers with past or planned travel to malaria-endemic countries of SSA were surveyed: VFRs diagnosed with malaria as reported through a state health department; members of the general VFR population (community); and VFR and non-VFR travelers presenting to a travel health clinic, both before their pretravel consultation and again, after return from travel. A Community Advisory Board of African immigrants and prior qualitative research informed survey development and dissemination. Across the three groups, 489 travelers completed surveys: 351 VFRs and 138 non-VFRs. VFRs who reported taking antimalarials on their last trip rated their concern about malaria higher than those who did not. Having taken five or more trips to SSA was reported more commonly among VFRs diagnosed with malaria than community VFRs (44.0% versus 20.4%; p = 0.008). Among travel health clinic patients surveyed before and after travel, VFR travelers were less successful than non-VFRs in adhering to their planned use of antimalarials (82.2% versus 98.7%; p = 0.001) and employing mosquito bite avoidance techniques (e.g., using bed nets: 56.8% versus 81.8%; p = 0.009). VFRs who visited the travel health clinic were more likely than VFR respondents from the community to report taking an antimalarial (83.0% versus 61.9%; p = 0.009), or to report bite avoidance behaviors (e.g., staying indoors when mosquitoes were out: 80.9% versus 59.5%; p = 0.009). We observed heterogeneity in malaria prevention behaviors among VFRs and between VFR and non-VFR traveler populations. Although VFRs attending the travel health clinic appear to demonstrate better adherence to malaria prevention measures than VFR counterparts surveyed in the community, specialized pretravel care is not sufficient to ensure chemoprophylaxis use and bite avoidance behaviors among VFRs. Even when seeking specialized pretravel care, VFRs experience greater barriers to the use of malaria prevention than non-VFRs. Addressing access to health care and upstream barrier reduction strategies that make intended prevention more achievable, affordable, easier, and resonant among VFRs may improve malaria prevention intervention effectiveness.

Background: Puerto Rico has experienced the full impact of the COVID-19 pandemic. Since SARS-CoV-2, the virus that causes COVID-19, was first detected on the island in March of 2020, it spread rapidly though the island’s population and became a critical threat to public health. Methods: We conducted a genomic surveillance study through a partnership with health agencies and academic institutions to understand the emergence and molecular epidemiology of the virus on the island. We sampled COVID-19 cases monthly over 19 months and sequenced a total of 753 SARS-CoV-2 genomes between March 2020 and September 2021 to reconstruct the local epidemic in a regional context using phylogenetic inference. Results: Our analyses reveal that multiple importation events propelled the emergence and spread of the virus throughout the study period, including the introduction and spread of most SARS-CoV-2 variants detected world-wide. Lineage turnover cycles through various phases of the local epidemic were observed, where the predominant lineage was replaced by the next competing lineage or variant after ~4 months of circulation locally. We also identified the emergence of lineage B.1.588, an autochthonous lineage that predominated in Puerto Rico from September to December 2020 and subsequently spread to the United States. Conclusions: The results of this collaborative approach highlight the importance of timely collection and analysis of SARS-CoV-2 genomic surveillance data to inform public health responses.

Background: Based on high population immunity to SARS-CoV-2 from prior infection, vaccination, or both, in fall 2023, regulatory agencies globally authorized/approved a single mRNA XBB.1.5-adapted vaccine dose for individuals aged ≥5 years regardless of prior vaccination. Methods: We conducted a systematic review on vaccine effectiveness (VE) of a single COVID-19 mRNA dose in individuals with a history of prior infection compared to individuals who were (i) SARS-CoV-2 naïve, (ii) unvaccinated with prior infection, and (iii) vaccinated with >1 dose with or without prior infection. We searched MEDLINE and Embase for studies published January 2021–October 2023. Data were synthesized following Synthesis Without Meta-Analysis guidelines; bias was assessed using the Newcastle-Ottawa Scale. This study was registered with PROSPERO (CRD42023453257). Results: Eighteen studies were eligible. None of these studies reported bivalent or XBB.1.5-adapted VE, and none reported VE for immunocompromised populations or children aged <5 years. Among those with prior infection, a single mRNA dose increased protection by 8–71% against infection (during Omicron BA.1, BA.4/5, or XBB predominance), 39–67% against symptomatic infection (BA.1, BA.2, or BA.4/5), and 25–60% against hospitalization or hospitalization or death (BA.1). VE of one dose was comparable to two doses among those with prior infection, and higher than following two doses without prior infection. Conclusions: A single dose of original mRNA COVID-19 vaccine provides similar protection to two doses for immunocompetent individuals aged ≥5 years in the current setting of high pre-existing immunity. This supports current recommendations for one dose to be given in advance of the respiratory season, regardless of history of infection or vaccination, with considerations for additional doses for certain populations including young children, older adults, and the immunocompromised.

The use of participatory approaches involving community stakeholders is novel in travel medicine research. We describe various community-based participatory methods, using the examples of community advisory boards (CABs), community-based organisations (CBOs), and focus groups as mechanisms for achieving a desired interventional outcome. While these methodologies can be applied to many settings, we used them to investigate barriers to malaria prevention in travellers visiting friends and relatives (VFRs) and to implement interventions targeting VFRs.