Transmission Of Tuberculosis Among illicit drug use Linkages (TOTAL): A cross-sectional observational study protocol using respondent driven sampling.

People who use illicit drugs (PWUDs) have been identified as a key at-risk group for tuberculosis (TB). Examination of illicit drug use networks has potential to assess the risk of TB exposure and disease progression. Research also is needed to assess mechanisms for accelerated TB transmission in this population. This study aims to 1) assess the rate of TB exposure, risk of disease progression, and disease burden among PWUD; 2) estimate the proportion of active TB cases resulting from recent transmission within this network; and 3) evaluate whether PWUD with TB disease have physiologic characteristics associated with more efficient TB transmission. Our cross-sectional, observational study aims to assess TB transmission through illicit drug use networks, focusing on methamphetamine and Mandrax (methaqualone) use, in a high TB burden setting and identify mechanisms underlying accelerated transmission. We will recruit and enroll 750 PWUD (living with and without HIV) through respondent driven sampling in Worcester, South Africa. Drug use will be measured through self-report and biological measures, with sputum specimens collected to identify TB disease by Xpert Ultra (Cepheid) and mycobacterial culture. We will co-enroll those with microbiologic evidence of TB disease in Aim 2 for molecular and social network study. Whole genome sequencing of Mycobacteria tuberculosis (Mtb) specimens and social contact surveys will be done for those diagnosed with TB. For Aim 3, aerosolized Mtb will be compared in individuals with newly diagnosed TB who do and do not smoke illicit drug. Knowledge from this study will provide the basis for a strategy to interrupt TB transmission in PWUD and provide insight into how this fuels overall community transmission. Results have potential for informing interventions to reduce TB spread applicable to high TB and HIV burden settings. Trial registration: Clinicaltrials.gov Registration Number: NCT041515602. Date of Registration: 5 November 2019.

Nuptial gifts and sexual selection in photinus fireflies.

The phenomenon of nuptial gift transfer during mating occurs across a remarkably wide range of taxa, and such male donations are likely to influence both pre-copulatory and post-copulatory sexual selection. This paper reviews what is known about nuptial gifts in Photinus fireflies (Coleoptera: Lampyridae), and discusses the adaptive significance of spermatophores in firefly mating systems. During copulation Photinus males transfer a spiral, gelatinous spermatophore to the female: sperm are released into the female's spermatheca for storage, while the remainder of the spermatophore disintegrates within a specialized gland. Radiolabelling studies indicate that male-derived protein is used to help provision the female's developing oocytes, and multiply-mated females show increased fecundity. As most Photinus adults do not feed, these studies suggest that females should continue to forage for matings to supplement their diminishing larval reserves, even after they have gained sufficient sperm to fertilize their eggs. Male spermatophore mass declines across sequential matings, and smaller spermatophores are associated with lower paternity success in situations where males compete for fertilizations. Declining spermatophore size across sequential matings may thus lead to diminishing reproductive returns for firefly males. Taken together, these results suggest that seasonal changes in nuptial gift availability may contribute to reversals of traditional courtship roles, with male choice and female-female competition occurring as spermatophore availability declines.