Miasis humana en Bahía Blanca, Argentina: periodo 2000 / 2005

Abstract

-Myiasis is the infestation of live human and vertebrate animals with dipterous larvae which, at least for a short period, feed on the host's dead or living tissue, liquid body-substance, or ingested food. The objective of this study was to identify the flies producing myiasis in Bahía Blanca city, Argentina, from 01/03/2000 to 31/05/2005. Seventeen clinical cases were studied. The larvae obtained from lesions were forwarded from laboratories and from public and private hospitals. Part of the larvae were fixed in alcohol 70º and processed according to the Mazza & Jörg technique (1939). The other part continued growing in flasks with meat in laboratory conditions to obtain the adults. The etiological agents of myiasis were identified by observing the diagnostic characteristics of the larvae III and of the adults, and by using taxonomic keys. Myiasis was produced by Cochlyiomia hominivorax (Coquerel) in thirteen of the cases and by Phaenicia sericata (= Lucila sericata) (Meigen) (Diptera: Calliphoridae) in the other four. The cases were traumatic and aural myiasis and happened from December to March. The ages of patients were four to eighty-six years and 76.5% of the cases occurred in male patients. Given the aggressiveness of these larvae, mainly C. hominivorax, in causing human myiasis, the importance of specific and quick diagnosis and of adequate treatment must be acknowledged.KEY WORDS: Diptera, Calliphoridae, Cochliomyia hominivorax, Phaenicia sericata RESUMEN -Se entiende por miasis a la infestación de vertebrados vivos por larvas de dípteros, que por lo menos durante un corto período, se alimentan de los tejidos vivos o muertos del hospedador, de sus sustancias corporales líquidas o del alimento por él ingerido. El objetivo del presente trabajo fue determinar las especies bioagentes de miasis humanas ocurridas en la ciudad de Bahía Blanca, Argentina, durante el período comprendido entre el 01/03/2000 y el 31/05/2005. Se estudiaron 17 casos clínicos. Las larvas extraídas de las lesiones fueron remitidas de laboratorios y hospitales públicos y privados de dicha ciudad. Parte de las larvas se fijó en alcohol 70° y se procesó según la técnica de Mazza & Jörg (1939). El resto se crió en condiciones de laboratorio hasta la obtención de los adultos. Se observaron las características diagnósticas de las larvas III y de los ejemplares adultos y se clasificaron taxonómicamente. Las especies bioagentes fueron: Cochliomyia hominivorax (Coquerel) en trece de los casos y Phaenicia sericata (= Lucila sericata) (Meigen) (Diptera: Calliphoridae) en los cuatro restantes. Las miasis fueron traumáticas y aurales, se presentaron durante los meses de Diciembre a Marzo, en la franja etaria de 4 a 86 años, siendo el 76,5% de los casos de presentación en pacientes masculinos. Teniendo en cuenta la voracidad de las larvas, principalmente las de C. hominivorax, resulta claro que el diagnóstico rápido de miasis y la aplicación del tratamiento adecuado son decisivos para que esta parasitosis se resuelva sin consecuencias grav...

Factors of Susceptibility of Human Myiasis Caused by the New World Screw-Worm,Cochliomyia hominivoraxin São Gonçalo, Rio de Janeiro, Brazil

“…However according to Marquez et al (2007), the higher occurrence of myiasis was among men, a fact also observed by Visciarelli et al (2007) who also described that 76.5% of the cases took place during the summer corroborating the results of this research when the percentage of parasitized males was 54.5%, and emphasizing that most of these men were employed in construction, farming, or domestic activities (75%). Such activities promote greater contact with the flies that cause myiasis.…”

First Report of Myiasis Caused by Cochliomyia hominivorax (Diptera: Calliphoridae) in a Diabetic Foot Ulcer Patient in Argentina

“…Visciarelli et al [17] have cited the species incriminated in human myiasis, C. hominivorax and Phaenicia sericata (also called Lucilia sericata ) (Meigen), to Bahia Blanca, Buenos Aires, Argentina. In all patients, myiasis occurred after traumas, lesions, and/or infectious processes that attracted the flies.…”

“…Visciarelli et al [17] also mentioned different pathologies, such as diabetes, otitis, and alcoholism, and certain behaviors, such as lack of body hygiene, lack of personal grooming, and/or rural tasks, that favour the permanence of the wounds by causing insensibility and increasing the probability of contact with flies. In the present work, we agree with the hypothesis that the exposed ulcer was a conditioning factor that, in combination with the patient's poor personal hygiene, rural tasks and insensibility associated with diabetes determined the degree of evolution of the myiasis in the patient.…”

Wound Myiasis in a Sixty-Two-Year-Old Man

“…Cochliomyia hominivorax and Chrysomya bezziana are cause dangerous myiasis due to their painful infestation and deep invasion (4). Wohlfahrtia magnifica (13), Dermatobia hominis (14), Lucilia cuprina (4) and L. sericata (15) are known to be causative agent for wound myiasis . Therefore, L. sericata and L. cuprina should be distinguished from each other as the presence of the three bristles on the dorsal mesothorax is considered the most common characteristic of L. sericata.…”