Andean cutaneous leishmaniasis (Andean-CL, uta) in Peru and Ecuador: the causative Leishmania parasites and clinico-epidemiological features

Canine leishmaniasis in the Americas: etiology, distribution, and clinical and zoonotic importance

Canine leishmaniasis is a widespread disease on the American continent, with cases reported from Uruguay to the USA and Canada. While numerous Leishmania spp. have been reported in dogs in this region, Leishmania infantum and Leishmania braziliensis are the most common etiological agents of canine leishmaniasis from a continental perspective. Nonetheless, other species may predominate locally in some countries. The participation of dogs in the transmission cycle of various Leishmania spp. has long been speculated, but evidence indicates that their role as reservoirs of species other than L. infantum is negligible. Various native wildlife (e.g., small rodents, marsupials, sloths, and monkeys) are, in fact, the primary hosts of Leishmania spp. in the Americas. In this review, an updated list of Leishmania spp. infecting dogs in the Americas is presented, along with their distribution and clinical and zoonotic importance.

Risk factors for cutaneous leishmaniasis in a high-altitude forest region of Peru

BACKGROUND

American cutaneous leishmaniasis (CL) is a neglected tropical disease typically associated with men working in remote, sylvatic environments. We sought to identify CL risk factors in a highly deforested region where anecdotal reports suggested an atypical proportion of women and children were infected with CL raising concern among authorities that transmission was shifting towards domestic spaces and population centers.

METHODS

We describe the characteristics of CL patients from four participating clinics after digitizing up to 10 years of patient data from each clinic's CL registries. We assessed risk factors of CL associated with intradomestic, peridomestic, or non-domestic transmission through a matched case-control study with 63 patients who had visited these same clinics for CL (cases) or other medical reasons (controls) between January 2014 and August 2016. The study consisted of an in-home interview of participants by a trained field worker using a standard questionnaire. Risk factors were identified using bivariable and multivariable conditional logistic regression.

RESULTS

Between 2007 and 2016, a total of 529 confirmed CL positives were recorded in the available CL registries. Children and working aged women made up 58.6% of the cases. Our final model suggests that the odds of sleeping in or very near an agricultural field were five times greater in cases than controls (p = 0.025). Survey data indicate that women, children, and men have similar propensities to both visit and sleep in or near agricultural fields.

CONCLUSIONS

Women and children may be underappreciated as CL risk groups in agriculturally dependent regions. Despite the age-sex breakdown of clinical CL patients and high rates of deforestation occurring in the study area, transmission is mostly occurring outside of the largest population centers. Curbing transmission in non-domestic spaces may be limited to decreasing exposure to sandflies during the evening, nighttime, and early morning hours. Our paper serves as a cautionary tale for those relying solely on the demographic information obtained from clinic-based data to understand basic epidemiological trends of vector-borne infections.

Prevalence of Genetically Complex Leishmania Strains With Hybrid and Mito-Nuclear Discordance

Approximately 20 Leishmania species are known to cause cutaneous, mucocutaneous, and visceral disorders in humans. Identification of the causative species in infected individuals is important for appropriate treatment and a favorable prognosis because infecting species are known to be the major determinant of clinical manifestations and may affect treatments for leishmaniasis. Although Leishmania species have been conventionally identified by multilocus enzyme electrophoresis, genetic analysis targeting kinetoplast and nuclear DNA (kDNA and nDNA, respectively) is now widely used for this purpose. Recently, we conducted countrywide epidemiological studies of leishmaniasis in Ecuador and Peru to reveal prevalent species using PCR-RFLP targeting nDNA, and identified unknown hybrid parasites in these countries together with species reported previously. Furthermore, comparative analyses of kDNA and nDNA revealed the distribution of parasites with mismatches between these genes, representing the first report of mito-nuclear discordance in protozoa. The prevalence of an unexpectedly high rate (~10%) of genetically complex strains including hybrid strains, in conjunction with the observation of mito-nuclear discordance, suggests that genetic exchange may occur more frequently than previously thought in natural Leishmania populations. Hybrid Leishmania strains resulting from genetic exchanges are suggested to cause more severe clinical symptoms when compared with parental strains, and to have increased transmissibility by vectors of the parental parasite species. Therefore, it is important to clarify how such genetic exchange influences disease progression and transmissibility by sand flies in nature. In addition, our aim was to identify where and how the genetic exchange resulting in the formation of hybrid and mito-nuclear discordance occurs.

Three Alkaloids from an Apocynaceae Species, Aspidosperma spruceanum as Antileishmaniasis Agents by In Silico Demo-case Studies

This paper is focused on demonstrating with a real case that Ethnobotany added to Bioinformatics is a promising tool for new drugs search. It encourages the in silico investigation of "challua kaspi", a medicinal kichwa Amazonian plant (Aspidosperma spruceanum) against a Neglected Tropical Disease, leishmaniasis. The illness affects over 150 million people especially in subtropical regions, there is no vaccination and conventional treatments are unsatisfactory. In attempts to find potent and safe inhibitors of its etiological agent, Leishmania, we recovered the published traditional knowledge on kichwa antimalarials and selected three A. spruceanum alkaloids, (aspidoalbine, aspidocarpine and tubotaiwine), to evaluate by molecular docking their activity upon five Leishmania targets: DHFR-TS, PTR1, PK, HGPRT and SQS enzymes. Our simulation results suggest that aspidoalbine interacts competitively with the five targets, with a greater affinity for the active site of PTR1 than some physiological ligands. Our virtual data also point to the demonstration of few side effects. The predicted binding free energy has a greater affinity to Leishmania proteins than to their homologous in humans (TS, DHR, PKLR, HGPRT and SQS), and there is no match with binding pockets of physiological importance. Keys for the in silico protocols applied are included in order to offer a standardized method replicable in other cases. Apocynaceae having ethnobotanical use can be virtually tested as molecular antileishmaniasis new drugs.

Natural Leishmania (Leishmania) mexicana infection and biting activity of anthropophilic sand fly Lutzomyia ayacuchensis in the Ecuadorian Andes

To elucidate the transmission mode of Andean cutaneous leishmaniasis (Andean-CL), natural Leishmania infection and biting activity of sand flies were tested in a selected sylvatic focus of the endemic area of the Ecuadorian Andes. Monthly sand fly collections and dissections were conducted during 12 months from July 2018 to June 2019. The Leishmania positive specimens/slides with innumerable amounts of actively mobile flagellates made us easy to detect positive sand flies. The promastigotes observed located in the anterior and posterior midgut, without the hindgut localization. The parasite isolated was identified as L. (L.) mexicana by cytochrome b gene analysis. No other Leishmania or flagellate species parasitic in sand flies was observed in the area. Only Lu. ayacuchensis was caught throughout. Monthly microscopic examination of Lu. ayacuchensis revealed 0.75-8.33% of natural L. (L.) mexicana infection rates. Higher Leishmania infection months were present at the end of the wet season of the Andes, while higher sand fly numbers occurred during the dry season. Diurnal biting (blood meal seeking) activity of sand flies started around 17:30 before sunset, increased between 18:00 and 19:30, and thereafter decreased drastically probably because of low temperature (15-18 °C) in the area. The results provide information important for the planning of vector control strategy and management of the disease in the Andean-CL endemic area of Ecuador.

A Clinicoepidemiological Study of Pediatric Cutaneous Leishmaniasis in Sinjar Province, Iraq

Cutaneous leishmaniasis (CL) is a major health problem worldwide. Although CL is a common disease among children, treatment regimens for the pediatric age group are based on extrapolation of efficacy data in adults. The present study aimed to evaluate the treatment outcome of CL in preschool-age children and the factors influencing the outcome. Two hundred ninety-four children were diagnosed with CL between December 2018 and March 2019 in Sinjar Province, Iraq. All patients were treated with intralesional injections of sodium stibogluconate and followed up for 3 months after the completion of treatment. The treatment success rate was 99% (291/294). A statistically significant association was found between the number of doses per lesion and the number of lesions (P = 0.002; CI = 0.066-0.2875). No association was found between the number of lesions, age, gender, or the presence of livestock and the treatment outcome. In conclusion, treatment success rate was high with the use of intralesional injection of sodium stibogluconate. A significant association was found between the number of lesions and the number of doses. Further studies are required to assess the treatment outcome indicators, including the genotype of leishmania.

The 2019 Pan American games: Communicable disease risks and travel medicine advice for visitors to Peru - Recommendations from the Latin American Society for Travel Medicine (SLAMVI)

The next Pan American Games will be held in Peru in the period July-August 2019. Around 6680 participants from 41 countries are expected to take part in the event. There will be a total of 62 sport disciplines. This event poses specific challenges, given its size and the diversity of attendees. Such gatherings also have potential for the transmission of imported or endemic communicable diseases, including measles in view of the global outbreak situation, but also tropical endemic diseases. In anticipation of increased travel, a panel of experts from the Latin American Society for Travel Medicine (SLAMVI) developed the current recommendations taking into consideration the epidemiology and risks of the main communicable diseases at potential destinations in Peru, recommended immunizations and other preventives measures. These recommendations can be used as a basis for advice for travelers and travel medicine practitioners. Mosquito-borne infections also pose a challenge. Although Lima is malaria free, travelers visiting Peruvian high-risk areas for malaria should be assessed regarding the need for chemoprophylaxis. Advice on the correct timing and use of repellents and other personal protection measures is key to preventing vector-borne infections. Other important recommendations for travelers should focus on preventing water- and food-borne diseases including travelers' diarrhea. This paper addresses pre-travel, preventive strategies to reduce the risk of acquiring communicable diseases during the Pan American Games and also reviews the spectrum of endemic infections in Lima and Peru to facilitate the recognition and management of infectious diseases in travelers returning to their countries of origin.

A clinical study of cutaneous leishmaniasis in a new focus in the Kurdistan region, Iraq

Leishmaniasis is caused by protozoan parasites of the genus Leishmania and is a major health problem in various parts of the world. Cutaneous leishmaniasis (CL) occurs, among others, in unpredictable outbreaks after wars and disasters. After the last war in Iraq, the collapse of the health system led to the spread of infectious diseases, including CL. Between September 2016 and November 2017, all patients with confirmed CL having one or more skin lesion(s) were referred to a regional health center in Musol City within the Rabeea District. During this period, 1539 patients visited the clinic. A total of 190 patients were excluded from the study because of poor follow-up. The treatment success rate was 97.7% (1319/1349). Statistically significant associations were found between number of lesions and treatment failure (p = 0.0018; OR = 1.4430; CI = 1.1466–1.8161), number of doses and number of lesions (Pearson’s correlation coefficient = 0.095; p = 0.001), and the lack of municipality services and number of doses used for the treatment (p = 0.008; OR = 1.0629; CI = 1.0158–1.1122). To conclude, the highest number of patients with CL in the city of Musol was recorded after the war in Iraq. The treatment success rate was high, which reflected the strict treatment and follow-up program. An urgent plan is needed to stop the spread of infection.

Leishmaniasis caused by Leishmania (Viannia) guyanensis in north-central Pacific region of Ecuador: A clinico-epidemiological feature

The current four year study was undertaken to investigate the clinical and epidemiological features of Leishmania (Viannia) guyanensis infections in Valle Hermoso, Santo Domingo de Los Tsachilas province, north-central Pacific areas of Ecuador. A total of 155 parasitologically confirmed (Leishmania-amastigote-positive) clinical cases diagnosed at a rural health center during January 2014-December 2017 were analyzed thoroughly. Molecular characterization of the causative Leishmania parasites from different endemic sites within the study areas was performed by PCR amplification of cytochrome b (cyt b) sequencing. All the FTA-card and/or smear impregnated materials tested were characterized, and identified as L. (V.) guyanensis, without detecting any other Leishmania species. The following features were described: 1) the majority of patients were suffered from a single ulcer lesion (simple and mild to chronic), followed by multiple lesions, including recidiva cutis-"like" and Chiclero's ulcer-"like" clinical forms; 2) the majority (65.70%) of lesions were less than 10 mm in size, and distributed mainly on the upper body regions (arm, forearm, face, and neck including ear and head); 3) about 30% (29.68%) of the subjects tested were less than 10 years of age, strongly suggesting the intra- and/or peri-domestic transmission of the disease in the areas. The current clinico-epidemiological feature detected emphasizes the need for further such investigations of the L. (V.) guyanensis infections prevalent at different Pacific ecoregions of Ecuador, including Amazon regions.

EA, Cáceres AG, Velez LN, Villegas NV, Hashiguchi K, Mimori T, Uezato H, Kato H. Andean cutaneous leishmaniasis (Andean-CL, uta) in Peru and Ecuador: the vector Lutzomyia sand flies and reservoir mammals

The vector Lutzomyia sand flies and reservoir host mammals of the Leishmania parasites, causing the Andean cutaneous leishmaniasis (Andean-CL, uta) in Peru and Ecuador were thoroughly reviewed, performing a survey of literatures including our unpublished data. The Peruvian L. (V.) peruviana, a principal Leishmania species causing Andean-CL in Peru, possessed three Lutzomyia species, Lu. peruensis, Lu. verrucarum and Lu. ayacuchensis as vectors, while the Ecuadorian L. (L.) mexicana parasite possessed only one species Lu. ayacuchensis as the vector. Among these, the Ecuadorian showed a markedly higher rate of natural Leishmania infections. However, the monthly and diurnal biting activities were mostly similar among these vector species was in both countries, and the higher rates of infection (transmission) reported, corresponded to sand fly's higher monthly-activity season (rainy season). The Lu. tejadai sand fly participated as a vector of a hybrid parasite of L. (V.) braziliensis/L. (V.) peruviana in the Peruvian Andes. Dogs were considered to be principal reservoir hosts of the L. (V.) peruviana and L. (L.) mexicana parasites in both countries, followed by other sylvatic mammals such as Phyllotis andium, Didelphis albiventris and Akodon sp. in Peru, and Rattus rattus in Ecuador, but information on the reservoir hosts/mammals was extremely poor in both countries. Thus, the Peruvian disease form demonstrated more complicated transmission dynamics than the Ecuadorian. A brief review was also given to the control of vector and reservoirs in the Andes areas. Such information is crucial for future development of the control strategies of the disease.