Diagnosis Of Asymptomatic Carriers Research Articles

Asesoramiento genético a una portadora asintomática de DMD: Primer caso reportado en el Sistema de Salud Pública del Perú

La distrofia muscular de Duchenne (DMD) es una distrofinopatía rápidamente progresiva con herencia ligada al cromosoma X. Este reporte describe el caso de una mujer con historia familiar de hermano y sobrinos con DMD, que acudió a consulta para orientación e información sobre riesgos inherentes a una eventual planificación familiar. Le propusimos participar en un programa piloto de asesoramiento genético para determinar su estado de portador o no de la variante causal de DMD en la familia. Esta primera experiencia ilustra la importancia de tener un programa de asesoramiento genético para el diagnóstico de portadores asintomáticos de enfermedades neurogenéticas en regiones con bajos recursos. Se incluyen reflexiones y comentarios sobre aspectos positivos y retos presentados durante el proceso, las políticas de apoyo presente y futuro para el afronte de los complejos problemas planteados por éste y similares diagnósticos.

Role of Cytology in Detection of Unsuspected Carriers of Microfilariae: A Retrospective Study in National Capital Region (NCR), India

Background: Filariasis, a global problem, is a major public health issue in India. Despite its high incidence, it is unusual to detect microfilaria in cytological smears, though unexpected detection of microfilariae in fine needle aspiration cytology (FNAC), exfoliative and fluid cytology have been reported previously. The study analyzed the role of cytology in detection of asymptomatic carriers of microfilariae.Methods: This was a retrospective, observational study and included cases of filariasis from cytological records spanning five years. The epidemiological, clinical, hematologic and radiologic details were noted. The slides were retrieved and examined. Descriptive statistical analysis was utilized.Result: Filariasis was diagnosed in 0.03% of the total cytology cases studied during the period, constituting 0.04% of FNACs (two cases of inguino-scrotal swellings, two of breast lumps, one of thyroid swelling) and 0.02% of cervicovaginal smears (two cases). None of them was clinically suspected to be filariasis. Radiological examination was also misleading. None of the cases demonstrated raised leukocytosis or microfilaremia and eosinophilia was present in 3 cases (42.9%). Apart from microfilariae of Wuchereria bancrofti, eggs were present in one case. This was associated with inflammation in all cases, cell adherence in 42.9% and coexistent hyperplastic and neoplastic conditions in 57.1% cases.Conclusion: The detection of microfilariae in cytological material in the absence of clinical, radiologic or hematologic suspicion, in an area of relatively low prevalence of filaria, points to the need for a high index of suspicion and careful screening of all smears, as cytology may play an important role in the diagnosis of asymptomatic carriers of microfilariae.DOI:10.21276/APALM.1727

Global dynamics of a vaccination model for infectious diseases with asymptomatic carriers

In this paper, an epidemic model is investigated for infectious diseases that can be transmitted through both the infectious individuals and the asymptomatic carriers (i.e., infected individuals who are contagious but do not show any disease symptoms). We propose a dose-structured vaccination model with multiple transmission pathways. Based on the range of the explicitly computed basic reproduction number, we prove the global stability of the disease-free when this threshold number is less or equal to the unity. Moreover, whenever it is greater than one, the existence of the unique endemic equilibrium is shown and its global stability is established for the case where the changes of displaying the disease symptoms are independent of the vulnerable classes. Further, the model is shown to exhibit a transcritical bifurcation with the unit basic reproduction number being the bifurcation parameter. The impacts of the asymptomatic carriers and the effectiveness of vaccination on the disease transmission are discussed through through the local and the global sensitivity analyses of the basic reproduction number. Finally, a case study of hepatitis B virus disease (HBV) is considered, with the numerical simulations presented to support the analytical results. They further suggest that, in high HBV prevalence countries, the combination of effective vaccination (i.e. ≥ 3 doses of HepB vaccine), the diagnosis of asymptomatic carriers and the treatment of symptomatic carriers may have a much greater positive impact on the disease control.

Asymptomatic groin dermatophyte carriage detected during routine gynaecologic examinations

We investigated the epidemiological characteristics of both symptomatic and asymptomatic dermatophytic groin infections in 1970 women (age: 36.2 ± 12.5) during routine gynaecologic examinations. Bilateral groin samples were collected with sterile cotton swabs premoistened with sterile physiological saline. The samples were then separately inoculated onto Sabouraud glucose agar. Fungi were identified by sequencing the rDNA internal transcribed spacer region. Dermatophytes were recovered from five patients (four Trichophyton rubrum and one Arthroderma vanbreuseghemii, 0.25%) with a diagnosis of asymptomatic carriers (four) and tinea inguinalis (one). In one case, groin carriage converted into tinea inguinalis after 3 weeks. Analysis of risk factors indicated that patients of at least 49 years were more likely to be positive for dermatophyte isolation (P = 0.002). In conclusion, groin dermatophyte carriage is more common than tinea inguinalis and can potentially convert into a symptomatic infection.