Cutaneous leishmaniasis in Sri Lanka: a study of possible animal reservoirs

Distribution changes of cutaneous leishmaniasis: A postulated risk of disease transmission in Hambantota, Sri Lanka

BACKGROUND OBJECTIVES

Leishmaniasis is caused by various species of parasite Leishmania. Approximately twenty of them are pathogenic to mammals. In Sri Lanka, cutaneous leishmaniasis (CL) is an established vector-borne disease. CL originates and spreads mainly through sandfly bite in many endemic countries. The aim of the present study was to compare the geographical distribution and demographic features of CL cases in Hambantota district, Sri Lanka in 2014 and 2016.

METHODS

The patients who were presented to the Tangalle Base Hospital from June to December in 2014 and 2016 were examined and a descriptive study was carried out using a structured-questionnaire. Slit-skin smears were collected from each patient, Giemsa-stained and examined under the light microscope to identify Leishmania amastigotes.

RESULTS

Out of 256 and 314 suspected CL patients, 156 and 155 were identified positive for the year 2014 and 2016, respectively. Out of 12 District Secretary Divisions (DSD) in Hambantota district, the highest number of CL cases, 85 and 86 was reported from Tangalle DSD in 2014 and 2016 respectively. Number of identified CL patients in Beliatta DSD had increased from 50 to 67 during the study period. In both years, majority of CL patients were ≥50 years old with males more infected than females. Although CL association with occupations were insignificant, housewives were the highly (23%) infected occupants in this area.

INTERPRETATION CONCLUSION

Based on the present findings, geographical distribution within DSDs in Hambantota district had changed. This emphasizes the importance of CL as a health problem in Hambantota district.

Development of a Highly Sensitive Nested PCR and Its Application for the Diagnosis of Cutaneous Leishmaniasis in Sri Lanka

The recent surge in cutaneous leishmaniasis (CL) in Sri Lanka has rendered clinical diagnosis difficult; thus, laboratory confirmation is indispensable. A modified (two novel inner primers to detect CL caused by Leishmania donovani) nested Internal Transcribed Spacer-1 (ITS1) PCR-Restriction Fragment Length Polymorphism (RFLP) method was developed and tested. The sensitivity of the modified nested PCR was tested using serial dilutions (103 to 10−2) of the DNA extract of a cultured L. donovani DD8 strain. Patients (n = 194) from Southern Sri Lanka were examined clinically, microscopically (Slit Skin Smear-SSS) and using the modified nested PCR. The modified nested PCR detected 2.55 fg of parasite DNA compared to ITS1 PCR (25 fg) and detected more cases than SSS (94.3% vs. 77.3%; p < 0.01). The RFLP pattern was L. donovani in all cases. The modified nested PCR performed well in clinically doubtful lesions (95% by PCR vs. 60% by SSS; p < 0.01), ulcerated nodules (91% vs. 71.8%; p < 0.01) and plaques (100% vs. 66.7%; p < 0.01). SSS demonstrated sensitivity (80.9%), specificity (81.8%), PPV (98.7%) and NPV (20.5%) against modified PCR. Low parasite loads and atypical lesions can be diagnosed by the proposed method with higher accuracy.

Domestic mammals as reservoirs for Leishmania donovani on the Indian subcontinent: Possibility and consequences on elimination

Leishmania donovani is the causative agent of historically anthroponotic visceral leishmaniasis (VL) on the Indian subcontinent (ISC). L. donovani is transmitted by the sand fly species Phlebotomus argentipes. Our collaborative group and others have shown that sand flies trapped outside in endemic villages have fed on cattle and dogs in addition to people. Domestic animals are reservoirs for L. donovani complex spp., particularly L. infantum, in other endemic areas. Multiple studies using quantitative PCR or serological detection methods have demonstrated that goats, cattle, rats and dogs were diagnostically positive for L. donovani infection or exposure in eastern Africa, Bangladesh, Nepal and India. There is a limited understanding of the extent to which L. donovani infection of domestic animals drives transmission to other animals or humans on the ISC. Evidence from other vector-borne disease elimination strategies indicated that emerging infections in domestic species hindered eradication. The predominant lesson learned from these other situations is that non-human reservoirs must be identified, controlled and/or prevented. Massive efforts are underway for VL elimination on the Indian subcontinent. Despite these herculean efforts, residual VL incidence persists. The spectre of an animal reservoir complicating elimination efforts haunts the final push towards full VL control. Better understanding of L. donovani transmission on the Indian subcontinent and rigorous consideration of how non-human reservoirs alter VL ecology are critical to sustain elimination goals.

An investigation of a new cutaneous leishmaniasis endemic area in Western Sri Lanka

BACKGROUND

The aim was to investigate an emerging focus of cutaneous leishmaniasis (CL) in Gampaha district, Western Sri Lanka.

METHODS

Sociodemographics of CL patients in Mirigama, Gampaha district, were compared with controls using a structured questionnaire. Clinical data and geographic positioning system coordinates of patients were recorded. Sandflies collections were performed in four selected sites using indoor hand collection (162 units) and cattle-baited net traps (n=3).

RESULTS

Of 73 patients (mean age 43.6 y; SD 20), 58.9% were males. Lesions consisted of nodules (52.1%) and ulcers (47.9%). Single lesions were seen in 69.9% of patients, while 30.1% had multiple lesions. Except for one mucosal lesion, all the others were cutaneous. Treatment consisted of sodium stibogluconate and cryotherapy (46.6%), sodium stibogluconate (45.2%) or cryotherapy (8.2%). Multiple lesions were more likely to receive combination therapy (p=0.013). The majority of those employed (81.1%; 27/33) were engaged in outdoor work. Male gender, low education attainment and poor disease awareness were significant risk factors for CL (p<0.05). Four households reported multiple cases. Phlebotomus argentipes was detected in all cattle-baited net traps and 35.3% of indoor hand collection units.

CONCLUSIONS

CL is emerging in Gamapha district with Mirigama as the epicentre. Case distribution indicates local transmission, with P. argentipes as the probable vector.

Detection of Leishmania donovani DNA within Field-Caught Phlebotomine Sand Flies (Diptera: Psychodidae) in Three Cutaneous Leishmaniasis Endemic Foci of Kurunegala District, Sri Lanka

Leishmaniasis is a parasitic infection transmitted through the bite of female phlebotomine sand flies. Microscopy is the gold standard to detect parasites within the sand flies and for vector incrimination. However, molecular-based detection has become more popular nowadays in the identification of Leishmania parasites since it provides detection and species identification simultaneously with no need of laborious procedures. The entomological surveys were conducted monthly from May to October 2017 using standard entomological techniques. Field-caught sand flies were identified to the species level followed by DNA extraction. The polymerase chain reaction (PCR) was performed using species-specific primers to detect Leishmania donovani parasites. A total of 1,662 sand flies were encountered from the entomological surveys, and the majority of them were Phlebotomus argentipes (n = 1517; 91.27%), while others were Sergentomyia punjabiensis (n = 140; 8.72%). Leishmania donovani parasite DNA was detected only from P. argentipes (2.3%; n = 2). The detection of Leishmania DNA in P. argentipes suggests the possible role of this species as a vector for leishmaniasis in Sri Lanka.

Spatial Epidemiologic Trends and Hotspots of Leishmaniasis, Sri Lanka, 2001-2018

Leishmaniasis, a neglected tropical disease, is on the decline in South Asia. However, cases of cutaneous leishmaniasis have risen in Sri Lanka since 2001, and the lack of in-depth research on its epidemiologic characteristics hampers control efforts. We analyzed data collected from patients with cutaneous leishmaniasis in Sri Lanka during 2001-2018 to study temporal and geographic trends and identify and monitor disease hotspots. We noted a progression in case rates, including a sharp rise in 2018, showing temporal expansion of disease-prevalent areas and 2 persistent hotspots. The northern hotspot shifted and shrank over time, but the southern hotspot progressively expanded and remained spatially static. In addition, we noted regional incidence differences for age and sex. We provide evidence of temporally progressive and spatially expanding incidence of leishmaniasis in Sri Lanka with distinct geographic patterns and disease hotspots, signaling an urgent need for effective disease control interventions.

A Comprehensive Review of Cutaneous Leishmaniasis in Sri Lanka and Identification of Existing Knowledge Gaps

Purpose

Sri Lanka is endemic to cutaneous leishmaniasis and reported as the latest focus of leishmaniasis in the Asian subcontinent. Annually, the number of leishmaniasis cases is increasing; therefore, more efficient diagnostic tools, treatment methods and effective prevention measures are indispensable. For this reason, many studies were conducted regarding leishmaniasis infections in Sri Lanka; however, some areas need more attention. Thus, in this review, we comprehensively discussed the studies on leishmaniasis carried out in Sri Lanka.

Methods

Published articles on leishmaniasis in Sri Lanka were searched on PubMed, Google Scholar and ResearchGate databases. Inclusion criteria for the articles were based on keyword searches including ‘Leishmaniasis in Sri Lanka’, ‘Leishmaniasis vector in Sri Lanka’, ‘Sandfly species in Sri Lanka’, ‘Leishmaniasis epidemiology in Sri Lanka’ which are publicly accessible as of 15th July 2019.

Results

In this study, we evaluated and summarized the leishmaniasis reports in Sri Lanka and mainly focused on clinical presentation of leishmaniasis infection, genetic characteristics of Leishmania donovani Sri Lankan strain, geographical distribution and associated environmental factors, immunological aspects of the infection, vector, reservoir host, risk factors, diagnosis and treatment, and prevention and control. Furthermore, we identified the areas where further research is needed to fill the essential knowledge gaps.

Conclusions

Leishmaniasis has become a critically important parasitic infection in Sri Lanka, whereas the significant clinical form is cutaneous leishmaniasis. Prevalence of the leishmaniasis infections is reported from all the districts of the country. Therefore, more studies are essential to be carried out to fill the existing knowledge gaps emphasized in this review.

Socioeconomic, demographic and landscape factors associated with cutaneous leishmaniasis in Kurunegala District, Sri Lanka

Background

Leishmaniasis is a neglected tropical disease that affects countries in the developing world. In Sri Lanka, cutaneous leishmaniasis is the most common form of the disease. It is prevalent in dry and intermediate zones, mostly associated with rural settings. Understanding basic risk factors is critical in the management of the disease with effective interventions. This study is focused on assessing the demographic, socioeconomic and landscape factors associated with leishmaniasis in Kurunegala District, Sri Lanka.

Methods

A descriptive cross-sectional study was conducted. Households of the past patients and randomly selected households, which had no history of leishmaniasis cases were interviewed. The clinical, socioeconomic, demographic, landscape and awareness-related data were obtained using a pre-tested, interviewer-administered questionnaire.

Results

A total of 101 patients and a similar number of controls were included in the study. All the patients had the cutaneous form of the disease. Housewives and personnel with monthly incomes less than Rs. 10,000 (56.76 USD) were 3.9- and 9.5-times more prone to the disease, respectively, according to multivariate analysis. Presence of decaying garbage, termite hills, unclear areas, wet soil and gardening areas were always associated with the increased odds of acquiring the disease.

Conclusions

Demographic factors do not play a pivotal role in the prevalence of leishmaniasis in the area. Housewives, inhabitants with low incomes and individuals who live in areas with conditions suitable for sand fly breeding and resting are major groups with a higher risk of infection. Special attention must be given in raising awareness and environmental management in control activities.

Clinical and epidemiological characteristics of cutaneous leishmaniasis in Sri Lanka

Background

Leishmaniasis, a vector borne tropical/subtropical disease caused by the protozoan Leishmania is transmitted to humans by sandfly vectors Phlebotomus and Lutzomyia. The principal form found in Sri Lanka is cutaneous leishmaniasis (CL) and is caused by Leishmania donovani. A rising trend in disease prevalence has been observed recently in Sri Lanka and the island is in fact the newest endemic focus in South Asia. Determining the prevalence of smear positivity among clinically suspected CL patients, identifying risk factors and specific clinical presentations of CL in order to implement preventive and early treatment strategies were the objectives of this study.

Methods

A sample of 509 clinically suspected cases of CL referred to the Department of Parasitology from all across Sri Lanka between 2005 and 2015 was selected consecutively. Diagnosis was confirmed by microscopic visualization of the Leishmania amastigote from the slit skin smear. A structured questionnaire was used to identify exposure related risk factors and a clinical examination was performed to identify lesion characteristics.

Results

Out of 509 clinical cases, 41.5% (n = 211) were smear positive. The study population ranged from ages 1 to 80 years (mean age = 34.76) and the most affected age group was 40–49. Of the smear positives, 58.85% were males. Majority (47.86%) were from the North Western region (Kurunegala) of the country and were exposed to scrub jungles. Sand fly exposure (p = 0.04) and positive contact history (p = 0.005) were significant risk factors for smear positivity.

Erythema (p = 0.02), lack of pruritus (p = 0.02) and scaly appearance (p = 0.003) were significant lesion characteristics in smear positivity. Lesions were commonly found in the exposed areas and the commonest morphological type was papulo-nodular.

Conclusions

An increasing trend in the spread of cutaneous leishmaniasis from endemic to non-endemic areas has become evident. Positive contact history and sandfly exposure were significant risk factors for smear positivity which may indicate the possibility of human reservoir hosts in infection transmission. Lack of pruritus, scaly appearance and erythema were highly significant lesion characteristics associated with Leishmania positive smears which can be used for the clinical diagnosis of CL.

Efficacy of a new rapid diagnostic test kit to diagnose Sri Lankan cutaneous leishmaniasis caused by Leishmania donovani

Background

Cutaneous leishmaniasis (CL) in Sri Lanka is caused by Leishmania donovani. This study assessed the diagnostic value of a new rapid diagnostic immunochromatographic strip (CL-Detect^™ IC-RDT), that captures the peroxidoxin antigen of Leishmania amastigotes.

Methodology/Principal findings

We sampled 74 clinically suspected CL lesions, of which 59 (79.7%) were positive by PCR, 43 (58.1%) by Giemsa stained slit skin smear (SSS) and 21 (28.4%) by the new IC-RDT. All samples which were positive either by SSS or IC-RDT or both were positive by PCR. The sensitivities of the IC-RDT and SSS compared to PCR were 36% and 73%, respectively. Fifteen patients from this endemic region were negative by all three tests. Twenty two clinically non-CL skin lesions from a CL non-endemic region were also negative by all three methods. Specificity and PPV of both IC-RDT and SSS compared to PCR were 100%; the NPVs of IC-RDT and SSS were 37% and 58%, respectively. The median parasite grading of the 59 PCR positive samples was 2+ (1–10 parasites/100 HPFs) and IC-RDT positive lesions was 3+ (1–10 parasites /10HPFs). The duration of the lesion was not associated with IC-RDT positivity.

Conclusions/Significance

The median parasite grade of Sri Lankan CL lesions is low. The low sensitivities of SSS and CL Detect^™ IC-RDT may be due to low parasite counts or low expression of peroxidoxin antigen in amastigotes of the Sri Lankan L. donovani strain. Our results indicate that negative SSS has to be combined with PCR for confirmation of CL in Sri Lanka. The current commercially available IC-RDT is not suitable to diagnose CL in Sri Lanka; an IC-RDT with improved sensitivity to detect L. donovani would be a valuable addition in the diagnostic tool kit for Sri Lanka.

Potential Challenges of Controlling Leishmaniasis in Sri Lanka at a Disease Outbreak

The present works reviewed the existing information on leishmaniasis in Sri Lanka and in other countries, focusing on challenges of controlling leishmaniasis in the country, in an outbreak. Evidence from recent studies suggests that there is a possibility of a leishmaniasis outbreak in Sri Lanka in the near future. Difficulty of early diagnosis due to lack of awareness and unavailability or inadequacy of sensitive tests are two of the main challenges for effective case management. Furthermore, the absence of a proper drug for treatment and lack of knowledge about vector biology, distribution, taxonomy and bionomics, and reservoir hosts make the problem serious. The evident potential for visceralization in the cutaneous variant of L. donovani in Sri Lanka may also complicate the issue. Lack of knowledge among local communities also reduces the effectiveness of vector and reservoir host control programs. Immediate actions need to be taken in order to increase scientific knowledge about the disease and a higher effectiveness of the patient management and control programs must be achieved through increased awareness about the disease among general public and active participation of local community in control activities.

A Mathematical Study to Control Visceral Leishmaniasis: An Application to South Sudan

In this manuscript, we propose and analyze a compartmental model of visceral leishmaniasis (VL). We model the human population with six compartments including asymptomatic, symptomatic and PKDL-infected, animal population as second host and sandfly population as the vector. Furthermore, the non-adult stage of the sandfly population is introduced in the system, which was not considered before in the literature. We show that the increase in the number of host of sandfly population generates a backward bifurcation. Thus, multiple hosts will cause disease persistence even if the basic reproduction number ([Formula: see text]) is below unity. We perform a sensitivity analysis of important model parameters with respect to some epidemiologically significant responses. We validate our model by calibrating it to weekly VL incidence data from South Sudan for the year 2013. We perform cost-effectiveness analysis on different interventions: treatment, non-adult control, adult control and their different layered combinations based on their implementation cost (in USD) and case reduction. We also use a global sensitivity analysis technique to understand the effect of important parameters of our model on the implementation cost of different controls. This cost-effectiveness study and cost-sensitivity analysis are relatively new in existing literature of this disease.

Clinico-Epidemiological Patterns of Cutaneous Leishmaniasis Patients Attending the Anuradhapura Teaching Hospital, Sri Lanka

Cutaneous leishmaniasis (CL) caused by Leishmania donovani is an endemic vector-borne disease in Sri Lanka. Over 2,500 cases have been reported since 2000 and the number of CL cases has dramatically increased annually. Total 57 clinically suspected CL patients attending the dermatology clinic in Anuradhapura Teaching Hospital were recruited from January to June 2015. Slit skin smears and skin biopsies were taken from each of the subjects. Clinical and epidemiological data were obtained using interviewer administered questionnaire. Forty-three (75.4%) patients among 57 were confirmed positive for L. donovani. The majority of infected patients was males (P=0.005), and the most affected age group was 21–40 years. Soldiers in security forces, farmers, and housewives were identified as high risk groups. The presence of scrub jungles around the residence or places of occupation (P=0.003), the presence of sandflies (P=0.021), and working outsides more than 6 hr per day (P=0.001) were significantly associated with CL. The number of lesions ranged from 1–3, and the majority (76%) of the patients had a single lesion. Upper and lower extremities were the prominent places of lesions, while the wet type of lesions were more prevalent in females (P=0.022). A nodular-ulcerative type lesion was common in both sexes. The presence of sandflies, scrub jungles, and outdoor activities contributed to spread of Leishmania parasites in an endemic pattern. Implementation of vector control programs together with health education with regard to transmission and prevention of CL are necessary to control the spread of this infection.

Molecular and Serological Evidence of Leishmania Infection in Stray Dogs from Visceral Leishmaniasis-Endemic Areas of Bangladesh

Visceral leishmaniasis (VL), or kala-azar, is mainly caused by two closely related Leishmania species, Leishmania infantum and Leishmania donovani Leishmania infantum is responsible for zoonotic VL, with dogs as the main reservoir host in the Mediterranean, the Middle East, Asia, and South America. In the Indian subcontinent, VL is caused by L. donovani and is considered anthroponotic, although the only known vector, the sand fly, is zoophilic in nature. The role of domestic and stray dogs in VL transmission is still unclear in this area. We screened 50 stray dogs from VL-endemic areas of Bangladesh for serological and molecular evidence of Leishmania infection. We detected anti-Leishmania antibodies in six (12%) dog serum samples using rK39 immunochromatographic tests. We observed Leishmania kinetoplast DNA in 10 (20%) buffy coat DNA samples by real-time polymerase chain reaction (PCR), five of which were positive based on internal transcribed spacer 1-PCR. A sequencing analysis of the amplified products confirmed that the parasitic DNA was derived from L. donovani Our findings support the hypothesis that stray dogs are an animal reservoir for L. donovani in this endemic region. Further studies are required to determine the precise role of dogs in the epidemiology of VL in Bangladesh.

Characterisation of cutaneous leishmaniasis in Matara district, southern Sri Lanka: evidence for case clustering

Leishmaniasis is a neglected tropical disease transmitted by Phlebotomus spp. sand flies. Cutaneous leishmaniasis (CL) in Sri Lanka is caused by Leishmania donovani. Transmission patterns are different in Southern and Northern Sri Lanka. Current study examined the prevalence, risk factors and distribution of CL in Matara District, Southern Sri Lanka. Total of 2260 individuals from four District Secretariat divisions (DSDs) were screened by house to house surveys using an interviewer administered questionnaire. The study population had an age range of 1-90 years (median  =  43  ±  17.31), low monthly income ( < 20 000 LKR, 52.8%) and a male to female ratio of 1 : 2. Thirty eight patients were diagnosed by light microscopy, culture and/or PCR with a disease prevalence of 1.68%. Spatial mapping provided evidence for significant case clustering, which tended to be more prominent with proximity to forest areas. The risk factors identified were un-plastered brick walls, absence or low usage of protective measures against insect bites, low income and excessive time (>4 hours/day) spent outdoors. However, exposure of limbs while outdoors, unawareness about the disease, type of occupation, common water source as the mode of water supply and presence of animal shelters within 200 m were not associated with the risk of acquiring the disease. Peri-domestic transmission is likely to contribute to the observed case clustering with all age groups at risk of acquiring the infection. Human behavioural habits coinciding with that of the vector, sand fly are likely to enable host-vector contact promoting its spread. Appropriate vector control measures, improvement of housing conditions, public education regarding preventive measures are required to contain the spread of disease.

Exposure to Leishmania spp. and sand flies in domestic animals in northwestern Ethiopia

Background

Human visceral leishmaniasis caused by Leishmania donovani is considered an anthroponosis; however, Leishmania-infected animals have been increasingly reported in L. donovani foci, and the role of these animals as reservoirs for human L. donovani infection remains unclear.

Methods

We conducted a study of domestic animals (goats, sheep, cows, dogs, and donkeys) in three L. donovani foci in northwestern Ethiopia. Domestic animals were screened for Leishmania DNA and for anti-L. donovani IgG. Serum anti-sand fly saliva antibodies were used as a marker of exposure to the vector sand fly, Phlebotomus orientalis.

Results

Of 546 animals tested, 32 (5.9 %) were positive for Leishmania DNA, with positive animals identified among all species studied. Sequencing indicated that the animals were infected with parasites of the L. donovani complex but could not distinguish between L. infantum and L. donovani. A total of 18.9 % of the animals were seropositive for anti-L. donovani IgG, and 23.1 % of the animals were seropositive for anti-P. orientalis saliva IgG, with the highest seroprevalence observed in dogs and sheep. A positive correlation was found between anti-P. orientalis saliva and anti-L. donovani IgGs in cows, goats, and sheep.

Conclusions

The detection of L. donovani complex DNA in the blood of domestic animals, the reported seroprevalence to the L. donovani antigen, and the widespread exposure to sand fly saliva among domestic animals indicate that they are frequently exposed to Leishmania infection and are likely to participate in the epidemiology of Leishmania infection, either as potential blood sources for sand flies or possibly as parasite hosts.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-015-0976-1) contains supplementary material, which is available to authorized users.

Leishmaniosis of companion animals in Europe: an update

Leishmaniosis caused by Leishmania infantum is a vector-borne zoonotic disease endemic in southern Europe, but which is spreading northwards. Millions of dogs, cats and other non-conventional companion animals susceptible to L. infantum, living in European households, may develop a severe disease and contribute to the spread of leishmaniosis because of travelling or re-homing. Dogs are the main reservoir but other new reservoirs have recently been incriminated. Sand flies remain the sole proven vector and non-vectorial transmission has been reported at individual level and in areas where the vector is absent. Clinical disease affects only a proportion of infected dogs and a complex genetic background of immune response is responsible for this susceptibility. There is a wide range of serological and parasitological diagnostic tools available whose cost-effective use depends on a reasoned approach. Clinical response to treatment of sick dogs is variable. Clinical cure is often obtained but clinical recurrence can occur and post-therapy follow up should be maintained life-long. In Europe, vaccination can be combined with individual protection with pyrethroids as part of an integrated approach to prevention. L. infantum is the only species isolated from cats in Europe and xenodiagnosis substantiated that infected cats are infectious for sand flies. Feline infection may be frequent in endemic areas, but prevalence is generally lower than in dogs. When cats are tested by both serological and molecular techniques discordant results are often observed. Feline cases have been reported from endemic areas in Italy, France, Spain and Portugal, but four cases were also diagnosed in Switzerland in cats that had travelled to or been imported from Spain. Half of the cases were diagnosed in cats with impaired immune responses. Clinical manifestations compatible with feline leishmaniosis include lymph node enlargement, skin and mucocutaneous lesions, ocular lesions, chronic gingivostomatitis, hypergammaglobulinemia, and normocytic normochromic anemia. Cats have been empirically treated with some drugs used in dogs. Due to polymorphic clinical picture and the insidious progressive course, leishmaniosis can persist for a long time before dogs or cats are brought to a veterinarian and so diagnosis can be delayed. Exotic or new Leishmania spp. have been reported in humans, animals and vectors in Europe. This changing situation requires attention in Europe for designing epidemiological studies and control measures.

Cross-sectional study to assess risk factors for leishmaniasis in an endemic region in Sri Lanka

Sri Lanka reports significantly more cutaneous leishmaniasis (CL) cases than visceral leishmaniasis (VL) cases, both of which are caused by Leishmania donovani MON-37. A cross-sectional study conducted in an area with a high prevalence of CL prevalent included 954 participants of an estimated population of 61,674 to estimate the number of CL cases, ascertain whether there is a pool of asymptomatic VL cases, and identify risk factors for transmission. A total of 31 cases of CL were identified, of whom 21 were previously diagnosed and 10 were new cases. Using rK39 rapid diagnostic test to detect antibodies against Leishmania spp., we found that only one person was seropositive but did not have clinical symptoms of CL or VL, which indicated low transmission of VL in this area. χ(2) test, independent sample t-test, and multivariate analysis of sociodemographic and spatial distribution of environmental risk factors showed that living near paddy fields is associated with increased risk for transmission of CL (P ≤ 0.01).

A morphologically distinct Phlebotomus argentipes population from active cutaneous leishmaniasis foci in central Sri Lanka

Although the reported aetiological agent of cutaneous leishmaniasis (CL) in Sri Lanka is Leishmania donovani, the sandfly vector remains unknown. Ninety-five sandflies, 60 females and 35 males, collected in six localities in the district of Matale, central Sri Lanka, close to current active transmission foci of CL were examined for taxonomically relevant characteristics. Eleven diagnostic morphological characters for female sandflies were compared with measurements described for Indian and Sri Lankan sandflies, including the now recognised Phlebotomus argentipes sensu lato species complex. The mean morphometric measurements of collected female sandflies differed significantly from published values for P. argentipes morphospecies B, now re-identified as Phlebotomus annandalei from Delft Island and northern Sri Lanka, from recently re-identified P. argentipes s.s. sibling species and from Phlebotomus glaucus. Furthermore, analysis of underlying variation in the morphometric data through principal component analysis also illustrated differences between the population described herein and previously recognised members of the P. argentipes species complex. Collectively, these results suggest that a morphologically distinct population, perhaps most closely related to P. glaucus of the P. argentipess. I. species complex, exists in areas of active CL transmission. Thus, research is required to determine the ability of this population of flies to transmit cutaneous leishmaniasis.

Public awareness and attitudes towards cutaneous leishmaniasis in an endemic region in Saudi Arabia

BACKGROUND AND AIMS

One of the priorities in public health policy for the control of Cutaneous Leishmaniasis (CL) is to investigate associations between disease distribution, socio-demographical and environmental risk factors, so that rational prevention and control strategies can be developed. Assessment of baseline awareness of the disease amongst the endemic population would be one of the first steps in this direction. This study aims to provide qualitative information on lay perceptions of CL in an endemic area in Saudi Arabia. We also attempted to correlate these perceptions with associated socio-demographical backgrounds.

METHODS

This was a cross-sectional descriptive survey carried out in Al-Hassa, located in the Eastern Province of Saudi Arabia. The study included 1824 participants, age ranging from 15 to 63 years (mean 35.86±9.54 years).

RESULTS

Over 76% of the studied population recognized the infectious nature of CL. There was also good awareness regarding the clinical features of CL, but the awareness regarding the vector, transmission, risk factors and preventive methods were very poor. Our study demonstrated a significantly higher knowledge score correlated with regard to male gender, higher family income, age and a previous history of CL.

CONCLUSION

In our study we found low awareness for important epidemiological aspects like transmission of the disease, risk factors and prevention. Our study provides a baseline to understand and correct deficits in the perceptions and knowledge regarding CL in Saudi Arabia and would provide a template to design interventions.