h Earlier histopathology studies suggest that parasite loads may differ between cutaneous leishmaniasis (CL) and mucosal leishmaniasis (ML) lesions and between acute and chronic CL. Formal demonstration requires highly sensitive detection and accurate quantification of Leishmania in human lesional tissue. In this study, we developed a quantitative real-time PCR (qPCR) assay targeting minicircle kinetoplast DNA (kDNA) to detect and quantify Leishmania (Viannia) parasites. We evaluated a total of 156 lesion biopsy specimens from CL or ML suspected cases and compared the quantitative performance of our kDNA qPCR assay with that of a previously validated qPCR assay based on the glucose-6-phosphate dehydrogenase (G6PD) gene. We also examined the relationship between parasite load and clinical parameters. The kDNA qPCR sensitivity for Leishmania detection was 97.9%, and its specificity was 87.5%. The parasite loads quantified by kDNA qPCR and G6PD qPCR assays were highly correlated (r ‫؍‬ 0.87; P < 0.0001), but the former showed higher sensitivity (P ‫؍‬ 0.000). CL lesions had 10-fold-higher parasite loads than ML lesions (P ‫؍‬ 0.009). Among CL patients, the parasite load was inversely correlated with disease duration (P ‫؍‬ 0.004), but there was no difference in parasite load according to the parasite species, the patient's age, and number or area of lesions. Our findings confirm that CL and recent onset of disease (<3 months) are associated with a high parasite load. Our kDNA qPCR assay proved highly sensitive and accurate for the detection and quantification of Leishmania (Viannia) spp. in lesion biopsy specimens. It has potential application as a diagnostic and follow-up tool in American tegumentary leishmaniasis.

BackgroundCutaneous leishmaniasis (CL) is a skin disease caused by the protozoan parasite Leishmania. Few studies have assessed the influence of the sample collection site within the ulcer and the sampling method on the sensitivity of parasitological and molecular diagnostic techniques for CL. Sensitivity of the technique can be dependent upon the load and distribution of Leishmania amastigotes in the lesion.Methodology/Principal FindingsWe applied a quantitative real-time PCR (qPCR) assay for Leishmania (Viannia) minicircle kinetoplast DNA (kDNA) detection and parasite load quantification in biopsy and scraping samples obtained from 3 sites within each ulcer (border, base, and center) as well as in cytology brush specimens taken from the ulcer base and center. A total of 248 lesion samples from 31 patients with laboratory confirmed CL of recent onset (≤3 months) were evaluated. The kDNA-qPCR detected Leishmania DNA in 97.6% (242/248) of the examined samples. Median parasite loads were significantly higher in the ulcer base and center than in the border in biopsies (P<0.0001) and scrapings (P = 0.0002). There was no significant difference in parasite load between the ulcer base and center (P = 0.80, 0.43, and 0.07 for biopsy, scraping, and cytology brush specimens, respectively). The parasite load varied significantly by sampling method: in the ulcer base and center, the descending order for the parasite load levels in samples was: cytology brushes, scrapings, and biopsies (P<0.0001); in the ulcer border, scrapings had higher parasite load than biopsies (P<0.0001). There was no difference in parasite load according to L. braziliensis and L. peruviana infections (P = 0.4).Conclusion/SignificanceOur results suggest an uneven distribution of Leishmania amastigotes in acute CL ulcers, with higher parasite loads in the ulcer base and center, which has implications for bedside collection of diagnostic specimens. The use of scrapings and cytology brushes is recommended instead of the more invasive biopsy.

BackgroundTraditional methods of detecting Leishmania from cutaneous lesions involve invasive diagnostic procedures, such as scrapings, which cause discomfort, require technical expertise, and carry risks of invasive procedures. We compared the performance of 2 novel, molecular-based non-invasive methods for the diagnosis of cutaneous leishmaniasis (CL).MethodsConsecutive patients presenting to the Leishmania Clinic at the Hospital Nacional Cayetano Heredia were enrolled. PCR was performed on filter paper lesion impressions (FPLIs), cytology brushes, and lancets for detection of Leishmania DNA. Smears from lesion scrapings and leishmanin skin test were also performed. Outcome measures were sensitivity and specificity. Composite reference standard was any 2 of 5 tests positive. Species identification was performed by PCR assays of positive specimens.ResultsNinety patients with 129 lesions were enrolled, 117 of which fulfilled reference criteria for a diagnosis of CL. Of these 117 lesions, 113 were positive by PCR of lancets used for lesion scrapings versus 116 by PCR of FPLIs (p = 0.930) or 116 by PCR of cytology brushes (p = 0.930). Sensitivity and specificity of PCR on lancets were 96.6% [95% CI 93.3–99.9%] and 100%, respectively. Sensitivity and specificity of FPLI PCR were 99.1% [95% CI 97.4–100%] and 100%, respectively. Sensitivity and specificity of cytology brush PCR were 99.1% [95% CI 97.4–100%] and 100%, respectively. Giemsa-stained lesion smear and leishmanin skin test had inferior sensitivities at 47.9% [95% CI 38.9–57.0%] and 82.3% [95% CI 73.9–90.7%], respectively, compared to PCR of invasive or non-invasive specimens (p<0.001).ConclusionsCytology brush PCR constitutes a sensitive and specific alternative to traditional diagnostic assays performed on invasive specimens such as lesion scrapings. It performs comparatively to non-invasive FPLI PCR. This novel, rapid, and well-tolerated method has the potential for widespread use in the field and in pediatric populations where traditional specimen collection is difficult.

Abstract. Conventional understanding suggests that simultaneous infection with more than one species of Leishmania is unlikely. In Peru, co-infections are clinically relevant because causative species dictates prognosis, treatment response, and follow-up. We describe a case of Leishmania (Viannia) braziliensis and L. (V.) lainsoni co-infection in a Peruvian patient with cutaneous leishmaniasis.

Background: Malaria has become a threat to health in the tropical and other developing countries. No wonder this has become one of the components of the Millennium Development Goals (MDGs). Malaria accounts for one in five of all childhood deaths in Africa. Yet much of the impact of this disease on the world's children could be prevented with currently available interventions.Methods & Materials: This study was carried out in Aba, Abia State, Nigeria between the months of July and October, 2012. Three hundred patients were tested using thick film method for the presence of malaria parasites. A pre-tested structural questionnaire was used to obtain the demographic data and home management practices from parents of the children.Results: Out of 300 children sampled, 195 (65.0%) were infected with malaria parasites. Ninety seven (62.2%) of those infected were males, while 98 (68.1%) were females. However, the prevalence rate of infection among the males and females were statistically insignificant (P-value < 0.05). Children of age five had the highest prevalence of 73.8%, followed by the children of age two with prevalence rate of 68.0%. Children living in homes where preventive measures were adopted recorded lower rate of infection. Those using insecticide treated nets (ITNs) had the lowest rate of infection (23.1%). This is followed by those using combined window/door net plus insecticide sprays (45.5%), while the homes where no control measures were adopted recorded 92.7% rate of infection. Conclusion:The difference in prevalence rates among homes using different control measures were statistically significant (Pvalue > 0.05) and therefore malaria infection is dependent on the control measures adopted.