Raúl Romero-Cabello

Mucormycosis in children: a study of 22 cases in a Mexican hospital

We present a single‐centre, retrospective study (1985–2012) of 22 cases of mucormycosis in children. A total of 158 mucormycosis cases were identified, of which 22 (13.96%) were children. The mean age of the children was 10.3 years (range: 6 months–18 years), and 59% of the infections occurred in males. The rhinocerebral form was the main clinical presentation (77.27%), followed by the primary cutaneous and pulmonary patterns. The major underlying predisposing factors were diabetes mellitus in 68.18% of the patients and haematologic diseases in 27.7% of the patients. The cases were diagnosed by mycological tests, with positive cultures in 95.4% of the patients. Rhizopus arrhizus was the foremost aetiologic agent in 13/22 cases (59.1%). In 21 cultures, the aetiologic agents were identified morphologically and by molecular identification. In 10 cultures, the internal transcribed spacer region of the ribosomal DNA was sequenced. Clinical cure and mycological cure were achieved in 27.3% cases, which were managed with amphotericin B deoxycholate and by treatment of the underlying conditions.

Hyperinfection with Strongyloides stercoralis

Strongyloidiasis is caused by Strongyloides stercoralis, which commonly produces gastrointestinal problems. If immune systems are compromised, the nematode larvae may spread and produce Strongyloides hyperinfection. Diagnosis of strongyloidiasis is based on the observation of larvae in coproparasitological studies. We present a case of a 49-year-oldman, VIH, who developed Strongyloides hyperinfection, diagnosed postmortem. Our patient reached the dissemination stage, which resulted in severe damage to the stomach and intestine, perforation of the intestinal wall, as well as sepsis due to the dissemination of bacteria. The diagnosis is difficult because of the low larvae excretion in stools. It is usually performed by the microscopic examination of fresh and fixed enriched stool samples. Serology was reported to be useful for screening and follow-up after treatment. This case reaffirms that HIV immunosuppression favours the dissemination of S stercoralis larvae. Thus, a search for intestinal parasites should be considered in similar cases.

Cutaneous Myiasis Caused by Chrysomya bezziana Larvae, Mexico

To the Editor: We report a case of cutaneous myiasis caused by Chrysomya bezziana larvae in a 62-year-old woman who had a complex vascular cutaneous anomaly in her lower right extremity for 8 years. On physical examination, in September 2009, she had a nonlimping walk with pink and painful feet and an ulcerative lesion on the internal surface of the right leg above the internal malleolus. This ulcer was large, clean, without evidence of infection, and had tissue in the process of granulation. Adjacent to the upper edge of this lesion, we observed a second, crater-like ulcer ≈2.5 cm in diameter from which drained an abundant, highly purulent, serohematic material (Figure, panel A). Figure A) Crater-like ulcer ≈2.5 cm in diameter on internal surface of patient’s right leg. B) Chrysomya bezziana worms isolated from the ulcer. Approximately 10 days earlier, the patient had detected discharge of worms from the second lesion, motivating her to seek medical consultation. We performed surgical cleaning and manual removal of worms (Figure, panel B) and referred the patient for external consultation to control vascular, metabolic, and parasitologic evolution and for instruction in proper hygiene. The worms were identified as C. bezziana larvae by the Parasitology Laboratory of the Microbiology and Parasitology Department, Faculty of Medicine, National Autonomous University of Mexico. Myiasis, a zoonotic disease, is defined as invasion of human living tissue by eggs or larvae from flies of the order Diptera. Among the diverse types of human myiasis that can occur in tropical regions, those in skin tissue are the most frequent, especially those generated by flies of the family Calliphoridae, of which the predominant species are Cordylobia anthropophaga (tumbu fly); C. bezziana, and Oestrus ovis in Africa (1) and Dermatobia hominis (American warble fly) in Central and South America. Myiases have become increasingly relevant, particularly when human activity is carried out in environments with poor hygiene or in close proximity to domestic and peridomestic animals, such as dogs and rats (2). Human myiases generally are present in cavities or wounds but also can affect tissue, such as the skin, eyes, oral cavity, intestines, or urogenital area. C. bezziana larvae can usually be found infecting wounds or cutaneous ulcers but are occasionally found in normal skin (3–5). Tegumentary and exposed-cavity myiases are relatively easy to diagnose because the source larvae can be observed directly. As a result of the taxonomic study of the larvae based on their morphologic characteristics (6), we searched the Medline, PubMed, Scielo, and Lilacs databases for articles describing myiasis caused by the identified species. The published literature showed that no prior cases had been documented in Mexico, and only a few cases had been documented in other regions of North America. Old World flies, such as C. bezziana and O. ovis, are the most important producers of myiasis from an economic perspective (7). The larvae feed on living tissue causing highly traumatic lesions in a great variety of warm-blooded animals. These myiases present a great diversity of clinical profiles, depending on the affected sites. Occasionally, even after elimination of the larvae, they may have subsequent effects, such as septic arthritis or even death, particularly in newborns, older persons, or immunosupressed persons (8). The spread of this infection to other countries or even across continents is not yet clear, but an overriding factor is the massive population migration, which poses the risk for introduction of new species at different places in different seasons. No reports were found indicating that this infection could be spread in another form (e.g., by food or water). Another probable cause for spread of this infection is the global change of the weather that helps larvae to survive in places where they could not previously survive (9). In the case presented, the myiasis was limited to localized destruction of the tissue and was not associated with hemorrhagic problems or bacterial infections. However, myiasis can affect deeper structures, including striated muscle and eventually bone, causing severe destruction of these tissues. Considering the potential effects of this disease, timely diagnoses are critical to limit the damage, take appropriate hygiene measures, and if necessary, provide adequate treatment (10).

Unusual association of diseases/symptoms: Disseminated sporotrichosis

Sporotrichosis is a subacute or chronic infection caused by Sporothrix schenckii. It is a primary cutaneous infection and it has different clinical forms: disseminated by lymphatic vessels (75%), localised cutaneous form (20%), disseminated cutaneous and extracuteus rarely. The systemic disseminated sporotrichosis is considered a severe opportunistic infection. The best diagnostic test is the culture. The authors report a case of a 36-year-old man, originally from Puebla, Mexico, with a diagnosis of disseminated sporotrichosis. Differential diagnosis with other pathologies includes leishmaniasis, chromoblastomycosis, tuberculosis verrucose and lymphangitis. The development of unusual presentations in immunocompromised patients has been reported.

Miasis asociada a síndrome de complejo vascular periférico

* Laboratorio de Parasitologia, Departamento de Microbiologia y Parasitologia, Facultad de Medicina, UniversidadNacional Autonoma de Mexico, Mexico, D.F.** Servicio de Infectologia, Hospital General de Mexico, Secretaria de Salud, Mexico, D.F.***Unidad de Medicina Familiar No. 28 “Gabriel Mancera”, Instituto Mexicano del Seguro Social, Mexico, D.F.RAUL ROMERO-CABELLO*

Evaluation of the efficacy and security of quinfamide administered in a single dose of 300 mg in adult patients with intestinal amebiasis

Quinfamide is an intraluminal amebicidal with high therapeutic efficacy and low toxicity. Its mechanism of action consists in the intraluminally immobilization of the Entamoeba histolytica trophozoite, and gets its maximum concentration blood level in about 7 hours. The objective of this paper is to evaluate the therapeutic action of quinfamide with a single dose in patients having sub- acute or chronic intestinal amebiasis parasitologicaly demonstrated, and to probe its security. Adults with a coproparasitoscopic exam mean concentration-flotation, as well as a complete clinical study were sudied. The cases that result positive because of the identification of parasite forms of E. histolytica and that fulfill the inclusion requirements besides signing the consent letter were given a single 300 mg dose of quinfamide and were kept in the following days under strict observation with coproparasitoscopic control studies realized the next five, six, seven, fourteen and twenty one days. From 568 persons studied, 221 (38.9%) were positive to the presence of intestinal E. histolytica. The coproparasitoscopic control studies showed that in 35 persons (15.84%), the parasite forms continued to be in the feces; and 186 persons (84.16%) corresponded to negativized cases. The clinical follow up never revealed the presence of secondary effects with the administration of this drug. In conclusion, the therapeutic efficacy of a single dose of quinfamide in the treatment of E. histolytica infection was good in comparison with the quinfamide administration of the same dose but in three intakes a day.

Rare disease: Hyperinfection with Strongyloides stercoralis

Strongyloidiasis is caused by Strongyloides stercoralis, which commonly produces gastrointestinal problems. If immune systems are compromised, the nematode larvae may spread and produce Strongyloides hyperinfection. Diagnosis of strongyloidiasis is based on the observation of larvae in coproparasitological studies. We present a case of a 49-year-oldman, VIH, who developed Strongyloides hyperinfection, diagnosed postmortem. Our patient reached the dissemination stage, which resulted in severe damage to the stomach and intestine, perforation of the intestinal wall, as well as sepsis due to the dissemination of bacteria. The diagnosis is difficult because of the low larvae excretion in stools. It is usually performed by the microscopic examination of fresh and fixed enriched stool samples. Serology was reported to be useful for screening and follow-up after treatment. This case reaffirms that HIV immunosuppression favours the dissemination of S stercoralis larvae. Thus, a search for intestinal parasites should be considered in similar cases.

Hyperinfection withStrongyloides stercoralis

Strongyloidiasis is caused by Strongyloides stercoralis, which commonly produces gastrointestinal problems. If immune systems are compromised, the nematode larvae may spread and produce Strongyloides hyperinfection. Diagnosis of strongyloidiasis is based on the observation of larvae in coproparasitological studies. We present a case of a 49-year-oldman, VIH, who developed Strongyloides hyperinfection, diagnosed postmortem. Our patient reached the dissemination stage, which resulted in severe damage to the stomach and intestine, perforation of the intestinal wall, as well as sepsis due to the dissemination of bacteria. The diagnosis is difficult because of the low larvae excretion in stools. It is usually performed by the microscopic examination of fresh and fixed enriched stool samples. Serology was reported to be useful for screening and follow-up after treatment. This case reaffirms that HIV immunosuppression favours the dissemination of S stercoralis larvae. Thus, a search for intestinal parasites should be considered in similar cases.

Seroepidemiología de la fasciolosis en escolares de la Ciudad de México

El objetivo de esta investigacion es conocer la prevalencia de infeccion por Fasciola hepatica, mediante examen serologico, coprologicos y epidemiologico en una muestra de ninos aparentemente sanos residentes en la delegacion Coyoacan de la Ciudad de Mexico. En la busqueda de anticuerpos anti-Fasciola hepatica, se analizaron los sueros de 331 ninos de 6 a 12 anos de edad mediante la prueba de hemoaglutinacion indirecta (HAI). Se realizo examen coprologico de sedimentacion simple en serie de tres a todos los participantes. El estudio epidemiologico incluyo 6 variables. Resultados. Cinco de los ninos fueron seropositivos a F. hepatica con una seroprevalencia de 1.51%. El estudio coprologico no reporto huevos de F. hepatica. El analisis estadistico entre seropositividad y consumo de berros, alfalfa, y lechuga no resulto significativo (χ2 = 0.42, p = 0.84). Sin embargo se encontro una relacion estadisticamente significativa entre los parasitos y la edad de los sujetos. Este hallazgo coincide con la edad de los seropositivos. No se encontro asociacion entre seropositividad y vivienda, agua potable, drenaje, abastecimiento de agua o consumo de verduras crudas,(χ2=6.00,p = 0.11) la asociacion con el origen de la familia tambien fue negativo (χ2= 1.85, p = 0.17). Conclusiones. Aunque la Ciudad de Mexico no es una zona endemica, y no tiene caracteristicas adecuadas para la fasciolosis es importante reconocer que la existencia de residentes de origen multiple presenta riesgos como pudimos demostrar y es precisamente en la edad escolar la que se tiene como factor de riesgo demostrado