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1. Re-emergence of yellow fever in the neotropics — quo vadis?

   https://doi.org/10.1042/ETLS20200187  

   Sacchetto, Livia ; Drumond, Betania P. ; Han, Barbara A. ; Nogueira, Mauricio L. ; Vasilakis, Nikos ( December 2020 , Emerging Topics in Life Sciences)

   Low, Jenny (Ed.)

   Yellow fever virus (YFV) is the etiological agent of yellow fever (YF), an acute hemorrhagic vector-borne disease with a significant impact on public health, is endemic across tropical regions in Africa and South America. The virus is maintained in two ecologically and evolutionary distinct transmission cycles: an enzootic, sylvatic cycle, where the virus circulates between arboreal Aedes species mosquitoes and non-human primates, and a human or urban cycle, between humans and anthropophilic Aedes aegypti mosquitoes. While the urban transmission cycle has been eradicated by a highly efficacious licensed vaccine, the enzootic transmission cycle is not amenable to control interventions, leading to recurrent epizootics and spillover outbreaks into human populations. The nature of YF transmission dynamics is multifactorial and encompasses a complex system of biotic, abiotic, and anthropogenic factors rendering predictions of emergence highly speculative. The recent outbreaks in Africa and Brazil clearly remind us of the significant impact YF emergence events pose on human and animal health. The magnitude of the Brazilian outbreak and spillover in densely populated areas outside the recommended vaccination coverage areas raised the specter of human — to — human transmission and re-establishment of enzootic cycles outside the Amazon basin. Herein, we review the factors that influence the re-emergence potential of YFV in the neotropics and offer insights for a constellation of coordinated approaches to better predict and control future YF emergence events. 

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2. Experimental Susceptibility of North American Raccoons (Procyon lotor) and Striped Skunks (Mephitis mephitis) to SARS-CoV-2

   https://doi.org/10.3389/fvets.2021.715307  

   Francisco, Raquel ; Hernandez, Sonia M. ; Mead, Daniel G. ; Adcock, Kayla G. ; Burke, Sydney C. ; Nemeth, Nicole M. ; Yabsley, Michael J. ( January 2022 , Frontiers in Veterinary Science)

   Recent spillback events of SARS-CoV-2 from humans to animals has raised concerns about it becoming endemic in wildlife. A sylvatic cycle of SARS-CoV-2 could present multiple opportunities for repeated spillback into human populations and other susceptible wildlife. Based on their taxonomy and natural history, two native North American wildlife species —the striped skunk ( Mephitis mephitis ) and the raccoon ( Procyon lotor) —represent a high likelihood of susceptibility and ecological opportunity of becoming infected with SARS-CoV-2. Eight skunks and raccoons were each intranasally inoculated with one of two doses of the virus (10 3 PFU and 10 5 PFU) and housed in pairs. To evaluate direct transmission, a naïve animal was added to each inoculated pair 48 h post-inoculation. Four control animals of each species were handled like the experimental groups. At predetermined intervals, we collected nasal and rectal swabs to quantify virus shed via virus isolation and detect viral RNA via rRT-PCR and blood for serum neutralization. Lastly, animals were euthanized at staggered intervals to describe disease progression through histopathology and immunohistochemistry. No animals developed clinical disease. All intranasally inoculated animals seroconverted, suggesting both species are susceptible to SARS-CoV-2 infection. The highest titers in skunks and raccoons were 1:128 and 1:64, respectively. Low quantities of virus were isolated from 2/8 inoculated skunks for up to day 5 post-inoculation, however no virus was isolated from inoculated raccoons or direct contacts of either species. Neither species had gross lesions, but recovering mild chronic pneumonia consistent with viral insult was recorded histologically in 5/8 inoculated skunks. Unlike another SARS-CoV-2 infection trial in these species, we detected neutralizing antibodies in inoculated raccoons; thus, future wildlife serologic surveillance results must be interpreted with caution. Due to the inability to isolate virus from raccoons, the lack of evidence of direct transmission between both species, and low amount of virus shed by skunks, it seems unlikely for SARS-CoV-2 to become established in raccoon and skunk populations and for virus to spillback into humans. Continued outbreaks in non-domestic species, wild and captive, highlight that additional research on the susceptibility of SARS-CoV-2 in wildlife, especially musteloidea, and of conservation concern, is needed. 

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3. Higher West Nile Virus Infection in Aedes albopictus (Diptera: Culicidae) and Culex (Diptera: Culicidae) Mosquitoes From Lower Income Neighborhoods in Urban Baltimore, MD

   https://doi.org/10.1093/jme/tjaa262  

   Rothman, Sarah E ; Jones, Jennifer A ; LaDeau, Shannon L ; Leisnham, Paul T ( December 2020 , Journal of Medical Entomology)

   Andreadis, Theodore (Ed.)

   Abstract The temperate United States has experienced increasing incidence of mosquito-borne diseases. Recent studies conducted in Baltimore, MD have demonstrated a negative relationship between abundances of Aedes albopictus (Skuse) and Culex mosquitoes and mean neighborhood income level, but have not looked at the presence of pathogens. Mosquitoes collected from five socioeconomically variable neighborhoods were tested for infection by West Nile, chikungunya, and Zika viruses in 2015 and 2016, and again from four of the neighborhoods in 2017. Minimum infection rates of pooled samples were compared among neighborhoods for each year, as well as among individual blocks in 2017. West Nile virus was detected in both Ae. albopictus and Culex pools from all neighborhoods sampled in 2015 and 2017. No infected pools were detected in any year for chikungunya or Zika viruses, and none of the target viruses were detected in 2016. Infection rates were consistently higher for Culex than for Ae. albopictus. Minimum infection rate was negatively associated with mean neighborhood income for both species in 2015. Although earlier work has shown a positive association between block-level abandonment and mosquito abundance, no association was detected in this study. Still, we demonstrate that viral infection in mosquito pools can differ substantially across adjacent urban neighborhoods that vary by income. Though trap security and accessibility often inform city sampling locations, detecting and managing arboviral risk requires surveillance across neighborhoods that vary in socioeconomics, including lower income areas that may be less accessible and secure but have higher infection rates. 

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4. Risk factors for placental malaria, sulfadoxine-pyrimethamine doses, and birth outcomes in a rural to urban prospective cohort study on the Bandiagara Escarpment and Bamako, Mali

   https://doi.org/10.1186/s12936-022-04125-6  

   Vincenz, Claudius ; Dolo, Zachary ; Saye, Serou ; Lovett, Jennie L. ; Strassmann, Beverly I. ( March 2022 , Malaria Journal)

   Malaria in Mali remains a primary cause of morbidity and mortality, with women at high risk during pregnancy for placental malaria (PM). Risk for PM and its association with birth outcomes was evaluated in a rural to urban longitudinal cohort on the Bandiagara Escarpment and the District of Bamako.

   Placental samples (N = 317) were collected from 249 mothers who were participants in a prospective cohort study directed by BIS in the years 2011 to 2019. A placental pathologist and research assistant evaluated the samples by histology in blinded fashion to assess PM infection stage and parasite density. Generalized estimating equations (GEE) were used to model the odds of PM infection.

   In a multivariable model, pregnancies in Bamako, beyond secondary education, births in the rainy season (instead of the hot dry season), and births to women who had ≥ 3 doses of sulfadoxine-pyrimethamine (SP) instead of no doses were associated with reduced odds of experiencing PM (active and past infections combined). Births in later years of the study were strongly associated with reduced odds of PM. Maternal age, which was positively associated with offspring year of birth, was significant as a predictor of PM only if offspring year of birth was omitted from the model. Gravidity was positively associated with both maternal age and offspring year of birth such that if either variable was included in the model, then gravidity was no longer significant. However, if maternal age or year of offspring birth were not adjusted for, then the odds of PM were nearly two-fold higher in primigravida compared to multigravida. Birth outcomes improved (+ 285 g birth weight, + 2 cm birth length, + 75 g placental weight) for women who had ≥ 3 doses of SP compared to no doses, but no difference was detected in birth weight or length for women who had 2 instead of ≥ 3 SP doses. However, at 2 instead of ≥ 3 doses placentas were 36 g lighter and the odds of low birth weight (< 2500 g) were 14% higher. Severe parasite densities (> 10% erythrocytes infected) were significantly associated with decreases in birth weight, birth length, and placental weight, as were chronic PM infections. The women who received no SP during pregnancy (7% of the study total) were younger and lacked primary school education. The women who received ≥ 3 doses of SP came from more affluent families.

   Women who received no doses of SP during pregnancy experienced the most disadvantageous birth outcomes in both Bamako and on the Bandiagara Escarpment. Such women tended to be younger and to have had no primary school education. Targeting such women for antenatal care, which is the setting in which SP is most commonly administered in Mali, will have a more positive impact on public health than focusing on the increment from two to three doses of SP, although that increment is also desirable.

    

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5. A mixed methods analysis of access barriers to dermatology care in a rural state

   https://doi.org/10.1111/jan.14604  

   Cyr, Melissa E. ; Boucher, Daryl ; Korona, Shayna A. ; Guthrie, Barbara J. ; Benneyan, James C. ( October 2020 , Journal of Advanced Nursing)

   To identify significant patient and system access barriers and facilitators to dermatology care in one rural health system with limited dermatology appointment availability.

   Mixed methods study using data from electronic medical records, patient surveys, stakeholder semi‐structured interviews, and service area dermatologist demographics. Retrospective data were collected between 1 January 2017–1 March 2018, and interviews and surveys were conducted between June 1–August 31, 2018. Participants were recruited from two primary care practices in one rural Maine regional health system.

   Findings from thematic analyses, descriptive statistics, and statistical modelling were integrated using Chi‐square tests for homogeneity to develop a unified understanding. Statistical modelling using odd‐ratio logistic and linear regression were performed for each outcome variable of interest.

   Urgent referrals by primary care increased the likelihood of dermatology care overall (OR: 6.771;p = .007) and at nearby sites with limited availability (OR: 4.024;p = .024), but not at geographically further sites with higher capacities (p = .844). Referral under‐diagnosis occurred in 20.8% of those biopsied. Older (p = .041) or non‐working (p = .021) patients were more likely to remain unevaluated than seek more available but geographically further care.

   In rural areas with scarce appointment availability, primary care provider diagnostic accuracy may be an important barrier of dermatology care receipt and health outcomes, especially among at‐risk populations.

   Although melanoma mortality rates are decreasing throughout the US, little is known about why rates in Maine continue to rise. This study applied a comprehensive approach to identify several patient and system access barriers to dermatology care in one underserved rural regional health system. While specific to this population and large service area, these findings will inform improvement efforts here and support broader future research efforts aimed at understanding and improving health outcomes in this rural state.

    

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