New evidence for endemic circulation of Ross River virus in the Pacific Islands and the potential for emergence

The minor allele (A) of the rs373863828 variant (p.Arg457Gln) in CREBRF is restricted to indigenous peoples of the Pacific islands (including New Zealand Māori and peoples of Polynesia), with a frequency up to 25% in these populations. This allele associates with a large increase in body mass index (BMI) but with significantly lower risk of type-2 diabetes (T2D). It is unclear whether the increased BMI is driven by increased adiposity or by increased lean mass. Hence, we undertook body composition analysis using DXA in 189 young men of Māori and Pacific descent living in Aotearoa New Zealand. The rs373863828 A allele was associated with a trend toward increased relative lean mass although this was not statistically significant (p=0.06). Notably though this allele was associated with significantly lower circulating levels of the muscle inhibitory hormone myostatin (p<0.05). This was further investigated in two Arg458Gln knockin mouse models on FVB/Nj and C57Bl/6j backgrounds. Supporting the human data, significant increases in relative lean mass were observed in male knockin mice. This was more significant in older mice (p<0.01) where it was associated with increased grip strength (p<0.01) and lower levels of myostatin (p <0.05). Overall these results provide new evidence that the rs373863828 A-allele is associated with a reduction of myostatin levels which likely contributes to increased lean muscle mass component of BMI, at least in males.

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Temperature explains broad patterns of Ross River virus transmission across Australia

10.1101/286724 ◽

2018 ◽

Cited By ~ 1

Author(s):

Marta S. Shocket ◽

Sadie J. Ryan ◽

Erin A. Mordecai

Keyword(s):

Disease Transmission ◽

Pacific Islands ◽

Mechanistic Model ◽

Empirical Relationship ◽

Virus Transmission ◽

Thermal Response ◽

Nonlinear Effects ◽

Ross River Virus ◽

The Pacific ◽

The Tropics

ABSTRACTTemperature impacts the physiology of ectotherms, including vectors that transmit disease. While thermal biology predicts nonlinear effects of temperature on vector and pathogen traits that drive disease transmission, the empirical relationship between temperature and transmission remains unknown for most vector-borne pathogens. We built a mechanistic model to estimate the thermal response of Ross River virus, an important mosquito-borne pathogen of humans in Australia, the Pacific Islands, and potentially emerging worldwide. Transmission peaks at moderate temperatures (26.4°C) and declines to zero at low (17.0°C) and high (31.5°C) temperatures. The model predicted broad patterns of disease across Australia. First, transmission is year-round endemic in the tropics and sub-tropics but seasonal in temperate zones. Second, nationwide human cases peak seasonally as predicted from population-weighted seasonal temperatures. These results illustrate the importance of nonlinear, mechanistic models for inferring the role of temperature in disease dynamics and predicting responses to climate change.

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Seasonal Labor Mobility in the Pacific: Past Impacts, Future Prospects

Asian Development Review ◽

10.1162/adev_a_00156 ◽

2021 ◽

Vol 38 (1) ◽

pp. 1-31

Author(s):

John Gibson ◽

Rochelle-Lee Bailey

Keyword(s):

Pacific Islands ◽

Labor Mobility ◽

General Development ◽

Host Countries ◽

Quantitative Evidence ◽

The Pacific ◽

Seasonal Labor ◽

New Evidence ◽

Economic Density ◽

Positive Impacts

Abstract The Pacific islands have weak economic growth and limited structural change compared to the rest of developing Asia. Remoteness and low economic density are two causes. To mitigate these constraints, bilateral arrangements with Australia and New Zealand let Pacific workers seasonally migrate to access higher-paying, more dynamic labor markets. Managed circular schemes are designed to benefit employers in labor-intensive sectors like horticulture, Pacific workers with limited employment opportunities in their own countries, and the communities providing workers. Several studies show large, positive impacts, but more general development impacts have been harder to find. Likewise, clear quantitative evidence of positive impacts in host countries has been hard to obtain. In this paper, we review the main seasonal labor mobility schemes in the Pacific and provide new evidence on community-level and aggregate impacts.

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