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A Llanos-Cuentas

Publications and source records attributed to A Llanos-Cuentas.

At least 37 records · Page 2Linked to original sources
PubMed1994

Efficacy of 28-day and 40-day regimens of sodium stibogluconate (Pentostam) in the treatment of mucosal leishmaniasis.

The efficacy and toxicity of two regimens of antimony, 28 and 40 days of 20 mg of antimony/kg/day, were compared in the treatment of culture-positive mucosal leishmaniasis involving more than one anatomic site. Forty consecutive eligible Peruvians with infiltrative or ulcerative mucosal disease of the lips, nose, palate-uvula-pharynx, or larynx-epiglottis were randomized to receive either 28 days (P28) or 40 days (P40) of sodium stibogluconate (Pentostam). Treatment was prematurely terminated due to thrombocytopenia in three patients and two patients did not complete six months of follow-up. At one month post-treatment, 13% (2 of 16) of the P28 patients and 16% (3 of 19) of the P40 patients no longer had infiltrates or ulcers and were initially considered cured. During a further 11 months of follow-up, infiltrated lesions healed in eight more P28 patients and in 10 more P40 patients. The cure rate after 12 months of follow-up was therefore 63% for both groups (10 of 16 in the P28 group and 12 of 19 in the P40 group). The total of 13 patients who had infiltrates or ulcers at the 9-12-month follow-up were considered failures. All seven patients (three in the P28 group and four in the P40 group) whose lesions were culture-positive for Leishmania at some point in the 12 months after treatment, and who were thereby parasitologic failures, were also clinical failures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Molecular karyotype variation in Leishmania (Viannia) peruviana: indication of geographical populations in Peru distributed along a north-south cline.

Forty-one Leishmania peruviana isolates were selected along a north-south transect which crossed areas endemic for uta in three different biogeographical regions in the Peruvian Andes. The isolates were analysed by molecular karyotyping and hybridization with three chromosome-derived DNA probes. All the isolates could be distinguished from L. braziliensis by their pLb-134 hybridization patterns. However, the patterns with the other probes (pLb-168 and -22) could be used to cluster the Peruvian isolates in discrete groups (karyodemes) which varied in their level of similarity with L. braziliensis. The geographical distribution of these karyodemes supports the hypothesis that eco-graphical isolation has contributed to the heterogeneity of L. peruviana.

Animals↗
PubMed1993

A comparative field study of the relative importance of Lutzomyia peruensis and Lutzomyia verrucarum as vectors of cutaneous leishmaniasis in the Peruvian Andes.

A two-year field study of Andean cutaneous leishmaniasis (uta) in the valley of Purisima, Ancash Department, Peru has provided quantitative epidemiologic and entomologic evidence for the predominant role of Lutzomyia peruensis in the transmission of Leishmania peruviana in this endemic area. The monthly incidence in the valley was greatest in the wet season (from December to May), when Lu. peruensis was particularly endophilic. A significant correlation was detected between intradomiciliary (but not extradomiciliary) Lu. peruensis abundance and the monthly incidence of uta in the valley following a one-month time lag. In contrast, no significant correlation was detected between any measure of Lu. verrucarum abundance and the incidence of uta. Lutzomyia peruensis and Lu. verrucarum comprise more than 98% of all the sand fly captures made in this valley. The increase in incidence of uta with altitude, which reached a peak rate between 2,250 and 2,750 meters above sea level, was associated with an increase in the relative abundance of Lu. peruensis as compared with Lu. verrucarum. Seasonal and altitudinal variation was also detected in the peak time of activity for both sand fly species, a phenomenon that could significantly influence the transmission rate: later host-seeking sand flies being more likely to find sleeping, nondefensive, human hosts.

Altitude↗
PubMed1993

Diagnosis of Leishmania using the polymerase chain reaction: a simplified procedure for field work.

Oligonucleotide primers directed to the minicircle kinetoplast DNA of Leishmania strains supported enzymatic amplification of this DNA by the polymerase chain reaction (PCR). A single product of 70 basepairs was obtained from parasites belonging exclusively to the L. braziliensis complex. Direct sequencing of the amplified product confirmed its minicircle origin. Skin biopsy specimens from human patients were used directly for the PCR. A pulse incubation of such specimens with deoxyribonuclease I prior to the PCR increased the reliability of the assay. Nuclease disruption of the kinetoplast network was expected to make more copies of the minicircle accessible to amplification. Comparative results between the PCR and conventional parasitologic detection procedures indicate that the DNA detection approach presented is by far more sensitive for diagnostic purposes. Innovations in the PCR protocol are presented that adapt the diagnosis of leishmaniasis to settings with minimal equipment and that are distant from central laboratories.

Animals↗
PubMed1993

Karyotype polymorphism and conserved characters in the Leishmania (Viannia) braziliensis complex explored with chromosome-derived probes.

Molecular karyotype of 45 reference populations of Neotropical leishmanias was analyzed with ethidium bromide staining and with 6 chromosome-derived probes selected from a genomic library of Leishmania (Viannia) braziliensis. Size-conserved patterns were identified and found to be specific to subgenus Viannia and to its constitutive species. An important issue for epidemiology and clinical investigations was the discrimination between L. (V.) peruviana and L. (V.) braziliensis, 2 species found very similar by other genetic techniques, but responsible for totally different clinical patterns. The suggested existence of genetically distinct demes, or karyodemes, within the group-species might also show to be of importance, as these populations might differ in virulence, host-specificity and clinical manifestations.

Animals↗
PubMed1990

Efficacy and toxicity of sodium stibogluconate for mucosal leishmaniasis.

OBJECTIVE: To determine the efficacy and toxicity of the World Health Organization's (WHO) recommended treatment for mucosal leishmaniasis: antimony, 20 mg/kg body weight per day for 28 days. DESIGN: Open trial with 12-month follow-up. SETTING: Inpatient unit of a regional referral hospital in a developing country. PATIENTS: Twenty-nine consecutive eligible patients with culture-confirmed infection of the mucosa with Leishmania species who were otherwise healthy. Eight patients (28%) had mild to moderate disease (confined to the nasal mucosa). Twenty-one patients (72%) had severe disease (including the oropharynx as well as the nasal mucosa). INTERVENTION: Antimony, 20 mg/kg body weight intravenously every day for 28 days. Patients received antimony in the form of sodium stibogluconate. MEASUREMENTS AND MAIN RESULTS: Initial results of therapy were as follows: 63 of 72 lesions (88%) healed or markedly improved; all lesions were culture-negative for parasites; and 18 of 29 patients (62%) showed complete clinical and parasitologic cure of all lesions. By the 12-month follow-up examinations, however, 37 lesions had recurred, 8 new lesions had appeared, and only 8 patients (30%) showed clinical cure of all lesions. Of the 8 patients with mild to moderate disease, 6 were cured compared with only 2 of the 21 patients with severe disease. Side effects of this treatment regimen included T-wave inversion on electrocardiogram (4 patients), abnormal liver function tests (10 patients), and musculoskeletal pain (24 patients). No side effects occurred during week 1 of therapy. CONCLUSIONS: The only recommended treatment for mucosal leishmaniasis is ineffective in patients with severe disease. The acceptable toxicity of the regimen suggests that longer courses of therapy with antimony, or that trials with other antileishmanial agents alone or combined with antimony be evaluated as initial therapy for this disease.

Adult↗
PubMed1989

Genetic heterogeneity in Peruvian Leishmania isolates.

Leishmania were isolated from Peruvian patients with uta or espundia; genomic DNA was examined for restriction fragment length differences by Southern blot analysis using DNA probes for beta-tubulin and for the major surface antigen gp63. Using 5 different restriction endonucleases, Peruvian isolates show homogeneity when examined at the beta-tubulin locus. In contrast, the organisms demonstrated heterogeneity both within and between disease groups when examined for restriction site differences within the gp63 locus. The differences observed did not correlate with the 2 disease groups. Comparison of these Peruvian isolates to New World reference strains of the Leishmania braziliensis complex reveals no consistent pattern of identity with either L. b. guyanensis, L. b. panamensis, or L. b. braziliensis.

Animals↗
PubMed1988

The use of nonradioactive DNA probes for the characterization of Leishmania isolates from Peru.

We describe conditions for dot blot DNA hybridization studies using biotinylated kDNA probes from Leishmania. The sensitivity and specificity attained with biotinylated or 32P-labeled probes were equivalent. The lower level of detection obtained was 100 parasites that were blotted on nitrocellulose paper and then treated with Proteinase K. Studies were performed with 112 Leishmania isolates from Andean (uta) and sylvatic mucocutaneous (espundia) patients and all were determined to belong to the Leishmania braziliensis complex.

Animals↗
PubMedDate not supplied

Lutzomyia verrucarum can transmit Leishmania peruviana, the aetiological agent of Andean cutaneous leishmaniasis.

In much of the endemic area for cutaneous leishmaniasis (uta) in the Peruvian Andes, the only 2 anthropophilic sandfly species present are Lutzomyia peruensis and Lu. verrucarum. On the basis of a single confirmed isolation of Leishmania peruviana (the aetiological agent of uta) from a wild Lu. peruensis, and apparent associations between sandfly abundance and the incidence of uta, it is generally believed that Lu. peruensis is the most important vector. In this paper, a potential role for Lu. verrucarum in the transmission of uta is indicated by laboratory experiments which show that this species is vectorially competent for L. peruviana. Individual or pooled colonized sandflies were permitted to take a second blood meal on 22 susceptible golden hamsters at varying intervals after feeding on hamsters previously infected with L. peruviana. Transmission was achieved by a single infected sandfly (of a total of 59) following a 15 d incubation period. Transmission was recognized by the characteristic clinical response (footpad swelling) associated with hamsters which have been inoculated with L. peruviana, and by the presence of parasites in aspirates made from the swollen footpad, detected by the polymerase chain reaction (PCR) and by parasite isolations in biphasic blood-agar culture medium. The identity of the parasite isolates was also confirmed by PCR (specific for parasites in the L. braziliensis complex). This is the first reported experimental transmission of L. peruviana by any sandfly species.

Animals↗
PubMedDate not supplied

The fall and rise of Andean cutaneous leishmaniasis: transient impact of the DDT campaign in Peru.

A retrospective analysis was carried out on census data collected from house-to-house surveys during 1991-1992 in 4 areas endemic for Andean cutaneous leishmaniasis (uta) in the Department of Lima, Peru. Major changes in mean annual incidence in susceptible persons have taken place in these sites during the last 60 years. In particular, there is strong support for the hypothesis that, from the 1950s to the 1970s, the transmission rate was temporarily suppressed, largely as a by-product of the DDT house spraying campaign against malaria. These results are consistent with (i) anecdotal evidence, contemporary with the spraying campaign, and (ii) the official Ministry of Health records for the annual number of uta cases in the Departments of Lima and Ancash.

Adolescent↗
PubMedDate not supplied

Environmental risk factors for clinical malaria: a case-control study in the Grau region of Peru.

The role of environmental risk factors in clinical malaria has been studied mainly in Africa and Asia, few investigations have been carried out in Latin America. Field observations in northern coastal Peru, where the prevalence of malaria is high during the agricultural season, suggested that the risk of disease varied according to the characteristics of the house and the house environment. Environmental determinants of the risk of clinical malaria were therefore investigated through a case-control study: 323 clinical cases of malaria, recruited through community-based active case-finding, and 969 age-, sex- and village-matched controls were recruited into the study over a period of 12 months ending June 1997. Residual spraying of houses in the previous 6 months, living more than 100 m from a canal, a level of education equal to primary school or above and working in agriculture conferred significant protection from the risk of developing clinical malaria. The presence of spaces between the wall and roof in the subject's bedroom (eaves) and a house aged > 4 years statistically significantly increased the risk of disease. Based on these results we discuss possible control measures for malaria in this area of the country.

Adolescent↗