Human Wound Colonization by <I>Lucilia eximia</I> and <I>Chrysomya rufifacies</I> (Diptera: Calliphoridae): Myiasis, Perimortem, or Postmortem Colonization?

Abstract

The infestation of human or animal tissues by fly larvae has been given distinctive terminology depending on the timing and location of colonization. Wounds and orifices colonized by Diptera in a living human or animal are typically referred to as myiasis. When the colonization occurs after death, it is referred to as postmortem colonization and can be used to estimate the minimum postmortem interval. What happens when the human, as in the case presented here, has a necrotic limb while the human remains alive, at least for a short period of time? The case presented here documents perimortem wound colonization by Lucilia eximia (Wiedemann) and Chrysomya rufifacies (Macquart) and the considerations for approximating development temperatures and estimating the time of colonization (TOC). This represents the first record of L. eximia in human myiasis in the United States and the first record of the co-occurrence of L. eximia and C. rufifacies in human myiasis in the United States. The TOC was estimated using both ambient and body temperature. Insect colonization before death complicates the estimation of TOC and minimum postmortem interval and illustrates the problem of temperature approximation in forensic entomology casework.

Implications of entomological evidence during the investigation of five cases of violent death in Southern Brazil

“…Their mean weight was of 0.18 mg and they were between the irst and second larval instar. Estimated age was of 42.8 hours, and was calculated using a regression equation based on development of this species [26,53]. This inding corroborates with the PMI estimated by the medical of icer, i.e., the death would have occurred approximately two days before the corpse was found.…”

Intra-puparial development of Lucilia eximia (Diptera, Calliphoridae)

“…In the neotropics this species is found from the north of Mexico to south South America (Whitworth 2014), and had also been reported in forensic studies in Europe (Velásquez et al 2010), in North America (Debry et al 2013;Sanford et al 2014), in Central America (Garcés et al 2004;Calderón-Arguedas et al 2005), and in South America (Rocha et al 2010;RamosPastrana and Wolff 2011;Barros-Souza et al 2012;UrarahyRodrigues et al 2013;Ramos-Pastrana et al 2014). The objectives of this research were to analyze the intra-puparial development of Lucilia eximia, and to describe chronological and morphological changes that occur during this stage.…”

A metagenomic assessment of the bacteria associated with Lucilia sericata and Lucilia cuprina (Diptera: Calliphoridae)

“…Sterile techniques for rearing L. sericata are well established Sherman and Tran 1994), but in some situations (e.g., use of non-sterile maggots instead of sterile maggots), MDT can also cause septicemia (Mumcuoglu 2001). In some situations, more than two species can colonize a wound premortem, which can complicate calculation of minimum postmortem interval estimation when using insect evidence in death investigations (Sanford et al 2014). In all of these cases, knowledge of microbes associated with non-sterile larvae would aid in (1) identifying the likely sources of septicemia in the case of failed maggot debridement therapy, (2) interpreting the results of potentially non-sterile ES experiments, (3) identifying bacteria that are unaffected by the feeding of Lucilia larvae, and (4) identifying bacteria that attract different blow flies for oviposition pre-or postmortem.…”