Burden and risk factors of cutaneous leishmaniasis in a peri-urban settlement in Kenya, 2016

Inter-individual and inter-regional variability of breast milk antibody reactivity to bacterial lipopolysaccharides

Breast milk is a vital source of nutrients, prebiotics, probiotics, and protective factors, including antibodies, immune cells and antimicrobial proteins. Using bacterial lipopolysaccharide arrays, we investigated the reactivity and specificity of breast milk antibodies towards microbial antigens, comparing samples from rural Kenya and urban Switzerland. Results showed considerable variability in antibody reactivity both within and between these locations. Kenyan breast milk demonstrated broad reactivity to bacterial lipopolysaccharides, likely due to increased microbial exposure. Antibodies primarily recognized the O-antigens of lipopolysaccharides and showed strong binding to specific carbohydrate motifs. Notably, antibodies against specific Escherichia coli O-antigens showed cross-reactivity with parasitic pathogens like Leishmania major and Plasmodium falciparum, thus showing that antibodies reacting against lipopolysaccharide O-antigens can recognize a wide range of antigens beyond bacteria. The observed diversity in antigen recognition highlights the significance of breast milk in safeguarding infants from infections, particularly those prevalent in specific geographic regions. The findings also offer insights for potential immunobiotic strategies to augment natural antibody-mediated defense against diverse pathogens.

Knowledge, attitude, practices and treatment-seeking behaviour concerning cutaneous leishmaniasis among rural hyperendemic communities in western Yemen

Cutaneous leishmaniasis (CL), a neglected tropical disease (NTD), is a major public health problem in Yemen with widespread distribution in rural areas. Evaluating the knowledge and understanding of people's beliefs towards the disease is essential to the implementation of effective control measures. This study aims to assess the knowledge, attitudes, practices (KAP) and treatment-seeking behaviour concerning CL among rural populations in the western highlands of Yemen. A community-based cross-sectional study was conducted among 289 household heads in four rural areas of the Utmah District. Data were collected using a pre-tested questionnaire. All the participants had heard about the disease; however, only 9.3% attributed it to sandflies. Nearly half (48.1%) of the participants could not mention any preventive measures for CL, and nearly two-thirds (65.4%) could not do so for sandflies. The overall 'good' knowledge about CL was found to be 51.2%, and it was 33.9% for sandflies. The participants' attitude and prevention practices towards CL were not satisfactory, as only 38.1% and 16.3% had a positive attitude and good CL-related prevention practices, respectively. Moreover, 45.7% believed CL to be a stigmatising disease, and 50% had used traditional remedies to treat suspected CL lesions. Multivariate analyses showed that age, sex, presence of CL-confirmed cases in the same household, residency, occupation and monthly household income were the significant predictors associated with KAP concerning CL among the participants. The findings support an urgent need for integrated health education and community mobilisation interventions to improve awareness of these vulnerable populations about this devastating disease.

Magnitude and associated factors of cutaneous leishmaniasis among patients visiting Nefas Mewcha primary hospital, Northern Ethiopia, 2022: An institution-based Cross-sectional study

BACKGROUND

Cutaneous leishmaniasis (CL) is the most common neglected tropical disease, causing stigmatised skin lesions. It is an important public health concern, with 95% of cases occurring in low-income and middle-income countries. Despite its long-recognized endemicity and psychosocial impacts, it is largely overlooked.

OBJECTIVE

The main aim of this study is to investigate the magnitude and associated factors of CL in north-central Ethiopia.

DESIGN

An institution-based cross-sectional study was conducted.

SETTING

The study was conducted in Nefas Mewcha Primary Hospital (NMPH), north-central Ethiopia.

PARTICIPANTS

The study was conducted among 332 individuals visiting NMPH from June to July 2022.

PRIMARY AND SECONDARY OUTCOMES

The primary outcome was to estimate the burden of CL among patients visiting NMPH, and the secondary outcome was to identify factors associated with the presence or absence of CL. The association between predictor variables and CL was assessed using a binary logistic regression model. Statistical significance was declared at a p _value of <0.05.

RESULT

Out of the 332 study participants, 63 patients sought medical care with skin lesions, and 61 (18.37%, 95% CI: 14.5% to 22.9%) were patients with CL. Localized CL was the predominant type (86.9%). Male sex (adjusted OR (AOR): 4.51; 95% CI 1.94 to 10.45), older age (AOR 0.91, 95% CI: 0.87 to 0.94), secondary and tertiary educational status (AOR: 0.18, 95% CI: 0.05 to 0.6), poor knowledge of CL (AOR: 4.02, 95% CI: 1.81 to 9.76) and living with domestic animals (AOR: 5.29, 95% CI 3.24 to 7.5) were identified as predictors of CL.

CONCLUSION

In the study area, the magnitude of CL was found to be high. Being male and young, having low educational status, having poor knowledge and living with domestic animals increase the risk of acquiring CL. As a result, increasing the knowledge of the community through scaling up of health education programmes and reducing activities that increase individuals' exposure to sandflies should be prioritised.

A disfiguring neglected tropical disease sweeps war-torn Yemen: a community-based study of prevalence and risk factors of cutaneous leishmaniasis among rural communities in the western highlands

BACKGROUND

Cutaneous leishmaniasis (CL) is a major health problem in Yemen and is endemic in many rural areas across the country.

METHODS

A community-based cross-sectional survey followed by unmatched case-control comparisons was conducted among 612 participants in Utmah district, western Yemen. A total of 223 participants were included in the case-control analysis to identify the significant risk factors. Skin scrapping samples were examined by microscopy and internal transcribed spacer 1 nested polymerase chain reaction.

RESULTS

Overall, 33% (202/612) of the participants had active skin lesions and/or scars that met the clinical criteria for CL. A total of 90 (14.7%) participants had suspected active CL lesions; however, a prevalence of 8.7% (53/612) was obtained based on molecular and parasitological examination, with Leishmania tropica being the only causative agent identified. Multivariable logistic regression analyses showed that being ≤10 y old, being female, living in houses with cracked walls, living in the presence of other family members with typical ulcerating skin diseases and sleeping outside were factors significantly associated with an increased likelihood of having CL. Moreover, keeping livestock on the ground floor of the house was significantly associated with a decreased likelihood of having CL.

CONCLUSION

The study reveals an alarmingly high prevalence of CL among the studied population. Therefore there is an urgent need for effective control measures and improved treatment efforts against this devastating disease.

Characterizing cutaneous leishmaniasis in a conflict-affected region: a study from North Waziristan, Pakistan

Background/aim

Cutaneous leishmaniasis is an emerging tropical disease that remains a serious public health issue in Pakistan, particularly in North Waziristan. The current research was carried out to investigate the presence of cutaneous leishmaniasis in this region.

Materials and methods

This prospective observational study was conducted from October 2018 to December 2020 at District Head Quarter Hospital Miranshah in North Waziristan with the collaboration of the Pathology Department of Gomal Medical College Dera Ismail Khan, Khyber Pakhtunkhwa. Needle aspirates were used for the microscopic Giemsa-stained slides. SPSS was used for data analysis.

Results

Of the 5406 clinically-suspected cases, 2603(48.2%) were positive by microscopic examination. Of these 2603 patients, 1474 (57%) were male and 1129 (43%) were female. Most of the lesions were on the face, followed by upper and lower limbs. The 5-10-year age group had the highest percentage of 1167 (45%). A single lesion affected 96.6% of the patients, while 2.7% had double lesions and 0.7% had triple lesions. A high number of cutaneous leishmaniasis were seen from April to August, while the lowest number was seen November to December.

Conclusion

This study provides extensive information in relation to the existence of cutaneous leishmaniasis in the North Waziristan district of Pakistan, as well as the detailed demographic features of those affected by the disease.

Discovery of the vector of visceral leishmaniasis, Phlebotomus (Artemievus) alexandri Sinton, 1928, in Kenya suggests complex transmission dynamics

Visceral and cutaneous leishmaniasis are endemic to specific regions due to the ecological preferences of phlebotomine sand flies and Leishmania spp. transmission. Sand fly entomological data in northern Kenya are scarce due to limited studies and neglect of leishmaniasis. The aim of this study was to investigate: (i) sand fly diversity and distribution; (ii) occurrence of Leishmania DNA within sand flies; and (iii) blood-meal sources of sand flies in Laisamis, northern Kenya. We conducted an entomological survey during February and March of 2021 in five areas of Laisamis sub-county using standard CDC light traps. A total of 1009 sand flies (394 male and 615 female) were morphologically identified, and representative samples verified by PCR amplification and sequencing of the cytochrome c oxidase subunit 1 (cox1) gene. Similarly, we identified blood-meal sources and Leishmania DNA in female sand flies by PCR amplicon sequencing of the vertebrate cytochrome b (cyt b) gene and internal transcribed spacer 1 (ITS1) of the 28S rRNA gene, respectively. Sergentomyia clydei (59.8%) was the most abundant sand fly species. Though collected mainly from one locality (Tirgamo), 14.8% of samples belonged to Phlebotomus (Artemievus) alexandri Sinton, 1928. We detected DNA of Leishmania major in 5.19% of Ph. alexandri, whereas Leishmania adleri DNA was detected in S. clydei (7.51%), Sergentomyia squamipleuris (8.00%), and Sergentomyia africanus (8.33%). Nine of 13 blood-fed sand flies had obtained blood from humans, of which 33.3% had L. major DNA. Both Ph. alexandri and S. clydei primarily fed on humans and could potentially be involved in the transmission of cutaneous leishmaniasis. The findings of this study contribute to the understanding of sand fly vector populations and their potential to transmit leishmaniasis in the area.

The leishmaniases in Kenya: A scoping review

BACKGROUND

The leishmaniases are a group of four vector-borne neglected tropical diseases caused by 20 species of protozoan parasites of the genus Leishmania and transmitted through a bite of infected female phlebotomine sandflies. Endemic in over 100 countries, the four types of leishmaniasis-visceral leishmaniasis (VL) (known as kala-azar), cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL), and post-kala-azar dermal leishmaniasis (PKDL)-put 1.6 billion people at risk. In Kenya, the extent of leishmaniasis research has not yet been systematically described. This knowledge is instrumental in identifying existing research gaps and designing appropriate interventions for diagnosis, treatment, and elimination.

METHODOLOGY/PRINCIPAL FINDINGS

This study used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to determine the state of leishmaniases research in Kenya and identify research gaps. We searched seven online databases to identify articles published until January 2022 covering VL, CL, MCL, and/or PKDL in Kenya. A total of 7,486 articles were found, of which 479 underwent full-text screening, and 269 met our eligibility criteria. Most articles covered VL only (n = 141, 52%), were published between 1980 and 1994 (n = 108, 39%), and focused on the theme of "vectors" (n = 92, 34%). The most prevalent study types were "epidemiological research" (n = 88, 33%) tied with "clinical research" (n = 88, 33%), then "basic science research" (n = 49, 18%) and "secondary research" (n = 44, 16%).

CONCLUSION/SIGNIFICANCE

While some studies still provide useful guidance today, most leishmaniasis research in Kenya needs to be updated and focused on prevention, co-infections, health systems/policy, and general topics, as these themes combined comprised less than 4% of published articles. Our findings also indicate minimal research on MCL (n = 1, <1%) and PKDL (n = 2, 1%). We urge researchers to renew and expand their focus on these neglected diseases in Kenya.

The Therapeutic Effects of Curcumin-coated Gold Nanoparticle Against Leishmania Major Causative Agent of Zoonotic Cutaneous Leishmaniasis (ZCL): An In Vitro and In Vivo Study

We synthesized and characterized curcumin-coated gold nanoparticles (Cur@AuNPs) and investigated their stability, cytotoxicity, leishmanicidal activity in in vitro and in in vivo experiments. Cur@AuNPs synthesized through a simple one-pot green chemistry technique. The in vitro leishmanicidal activity of curcumin-coated gold nanoparticles against extracellular promastigotes and intracellular amastigotes of protozoan parasite Leishmania major (L. major) was determined by applying the tetrazolium reduction colorimetric quantitative MTT technique. For in vivo assessment, the footpad lesion size and parasite burden in two infection site organs including lymph nodes and footpads of susceptible BALB/c mice infected with L. major were measured. Mice immune responses in all study groups were quantified by measuring the levels of gamma interferon (IFN-γ) and interleukin-4 (IL-4). Viability of Leishmania promastigotes significantly diminished with the inhibition in promastigotes growth (IC₅₀) of 64.79 μg/mL and 29.89 μg/mL for 24 h and 48 h, respectively. In vitro nanoparticles treatment efficiently cleared the L. major amastigotes explanted in macrophages but had no harmful toxicity on the mice cells. In the in vivo condition, in the treated infected BALB/c mice the CL lesion size, Leishmania parasite burden, and IL-4 were decreased, while IFN-γ was significantly increased. The results suggest that Cur@AuNP was an effective compound against Leishmania parasite in vitro and in vivo, efficiently induced T-helper 1 (Th1) responses and augmented host cellular immune responses, and ending in a reduced Leishmania parasite burden. Therefore, it may be identified as a novel potential therapeutic approach for the local therapy of zoonotic CL treatment with high cure rates.

Environmental factors and building conditions for risk of cutaneous leishmaniasis in the northeast of Iran: a population-based case-control study

BACKGROUND

Leishmaniasis is a tropical disease that significantly affects countries in the developing world. This study evaluated the environmental factors and building conditions associated with cutaneous leishmaniasis (CL) in northeast Iran.

METHODS

A population-based case-control study was performed between 1 July 2018 and 1 March 2021 in northeast Iran; two controls were selected for each case. Patients and controls were compared for environmental factors, building conditions and demographic characteristics.

RESULTS

There were 170 confirmed leishmaniasis cases during the study period. Familiarity with people with active leishmaniasis in open areas of the body increased the odds of getting the disease (odds ratio [OR] 2.41 [95% confidence interval {CI} 1.18 to 4.93]). In the case group, the history of contact with animals such as sheep, goats, cows, mice and camels was significantly higher. Housewives (OR 0.08 [95% CI 0.02 to 0.27]) and self-employed people (OR 0.22 [95% CI 0.07 to 0.70]) were less likely to become infected. The individuals who lived in houses with asbestos cement roofs were more likely to become infected (OR 4.77 [95% CI 1.34 to 16.91]) compared with those who lived in houses with bituminous roofs.

CONCLUSIONS

The most significant risk factor identified in the present study was the type and condition of the home's roof. Housing construction improvement is vital to prevent leishmaniasis in northeast Iran.

A Community Based Survey of Knowledge, Attitudes, and Practices Concerning Leishmaniasis in Central Morocco

Leishmaniasis is a major health problem caused by a protozoan of the genus Leishmania, most commonly transmitted by infected female sand flies. Intersectoral collaboration is essential for the implementation of integrated vector management control with community participation. The present study aims to evaluate the knowledge, attitude and practices of the population toward leishmaniasis in central Morocco. A quantitative cross-sectional study was conducted using an administered questionnaire assisted by health professionals, on 750 people in the Marrakech Safi, endemic region of cutaneous leishmaniasis (CL). Of those, 702 agreed to be recruited for our study, of which 63,5% were women, 48,1% were aged between 18 and 40 years, and more than half of the participants (60%) were from rural areas. Overall, the knowledge, attitude and practices (KAPs) for leishmaniasis are too poor for more than 85% of the population in the study area. Basic knowledge and perceptions of leishmaniasis were good for 14,6% of respondents. While, 4,5% of the members had good knowledge of CL, only 0,7% had good level of knowledge about vesciral leishmaniasis (VL). Furthermore 3,7% of those polled have favorable attitudes and preventive practices. No association was found between knowledge and age, province or occupation. However, rural residents were four times more likely than urbain residents to have good basic knowledge (ORA = 4,74; CI95%: 1,04 -22,05). In addition, the female gender also has the chance to possess good basic knowledge and perceptions 3 times more than the men (ORA = 3,18; CI95%: 1,16 -8,69). The low level of KAPs regarding leishmaniasis proves the lack of community participation in the fight against leishmaniasis in central Morocco.

A novel connection between Trypanosoma brucei mitochondrial proteins TbTim17 and TbTRAP1 is discovered using Biotinylation Identification (BioID)

The protein translocase of the mitochondrial inner membrane in Trypanosoma brucei, TbTIM17, forms a modular complex in association with several other trypanosome-specific proteins. To identify transiently interacting proximal partner(s) of TbTim17, we used Biotinylation Identification (BioID) by expressing a modified biotin ligase-TbTim17 (BirA∗-TbTim17) fusion protein in T. brucei. BirA∗-TbTim17 was targeted to mitochondria and assembled in the TbTIM complex. In the presence of biotin, BirA∗-TbTim17 biotinylated several mitochondrial proteins. Interestingly, TbHsp84/TbTRAP1, a mitochondrial Hsp90 homolog, was identified as the highest enriched biotinylated proteins. We validated that interaction and colocalization of TbTim17 and TbHsp84 in T. brucei mitochondria by coimmunoprecipitation analysis and confocal microscopy, respectively. TbTim17 association with TbTRAP1 increased several folds during denaturation/renaturation of mitochondrial proteins in vitro, suggesting TbTRAP1 acts as a chaperone for TbTim17 refolding. We demonstrated that knockdown of TbTRAP1 reduced cell growth and decreased the levels of the TbTIM17, TbTim62, and mitochondrial (m)Hsp70 complexes. However, ATPase, VDAC, and Atom69 complexes were minimally affected. Additionally, the steady state levels of TbTim17, TbTim62, and mHsp70 were reduced significantly, but Atom69, ATPase β, and RBP16 were mostly unaltered due to TbTRAP1 knockdown. Quantitative proteomics analysis also showed significant reduction of TbTim62 along with a few other mitochondrial proteins due to TbTRAP1 knockdown. Finally, TbTRAP1 depletion did not hamper the import of the ectopically expressed TbTim17-2xMyc into mitochondria but reduced its assembly into the TbTIM17 complex, indicating TbTRAP1 is critical for assembly of TbTim17. This is the first report showing the role of TRAP1 in the TIM complex assembly in eukaryotes.

Determinants of cutaneous leishmaniasis among students in Delanta district, Northeast Ethiopia: A case-control study

Background and Aims

Cutaneous leishmaniasis (CL) is the most common form of leishmaniasis that causes skin lesions on exposed parts of the body. It is endemic in over 170 districts and highly prevalent in the northern and southern parts of Ethiopia. Thus, the aim of this study was to assess the determinants of CL among students of Wegeltena secondary school in Delanta district, Northeast Ethiopia.

Methods

This unmatched case-control study was conducted from January 4 to 20, 2021 at Wegeltena secondary school. Cases were students who had an active lesion of CL and controls were students who had never been infected with CL (no active lesions). A simple random sampling technique was utilized to select participants in the control group. Data were collected by using a pretested, interviewer-administered structured questionnaire. Bivariable and multivariable logistic regression analyses were performed and variables were declared determinants of CL at a p value of <0.05.

Results

A total of 225 students (58 cases and 167 controls) participated in the study. The mean age of cases and controls was 18.6 (SD ± 0.99 years) and 18.5 years (SD ± 1.17 years), respectively. In this study, 74.1% of cases and 51.5% of controls have been living in rural areas. Furthermore, being male (adjusted odds ratio [AOR] = 4.11; 95% confidence interval [CI]: 1.94-8.69), rural residents (AOR = 2.95; 95% CI: 1.33-6.52), living in areas where caves (AOR = 3.63; 95% CI: 1.24-10.59), nearby forest (AOR = 4.04; 95% CI: 1.42-11.51), and hyrax available (AOR = 2.43; 95% CI: 1.16-5.08) were significantly associated with CL.

Conclusion

In our study, sociodemographic and environmental factors were found to be determinants of CL. Therefore, reducing outdoor activities, wearing protective clothes, use of insecticide-treated nets, and destruction of sand fly breeding sites shall be implemented targeting the rural population that resides in areas where forests, caves, and hyraxes are prominent.

Analysis of associated risk factors among recurrent cutaneous leishmaniasis patients: A cross-sectional study in Khyber Pakhtunkhwa, Pakistan

BACKGROUND

Leishmaniasis is the second and fourth highest cause of mortality and morbidity respectively among all tropical diseases. Recurrence in the onset of leishmaniasis is a major problem that needs to be addressed to reduce the case fatality rate and ensure timely clinical intervention. Here we are investigating the association of risk factors with recurrent cutaneous leishmaniasis to address this issue.

MATERIAL AND METHODS

Patients received by Nasser Ullah Khan Babar Hospital in Peshawar, Pakistan from March 2019 to July 2020 were enrolled in this study. Those patients who developed symptoms after completion of treatment were included in Group-A while those who had atypical scars like leishmaniasis but were negative for cutaneous leishmaniasis were included in the comparison group tagged as Group B. All those individuals who had completed six weeks of treatment for CL but had normal complete blood counts (CBC) were included to avoid other underlying immunological pathologies, while we excluded those participants who had co-morbidities like diabetes, liver disease, cardiac disease, and pregnant and lactating women through their history Association was tested between Group-A and Group-B with other explanatory variables through chi-square test. The regression model was proposed to determine the predictors.

RESULT

A total of 48 participants of both sexes were included in the study with a mean age of 32.2 ± 15.10. The data suggest that females are overrepresented among the patients with recurrent leishmaniasis [21(53.8 %,); p = 0.07]. Compared to patients; healthy participants had a higher proportion of adults (19-59 years) versus adolescents (13-18 years) [26(66.7 %) vs 07(17.9), p = 0.004]. Multivariate logistic regression analysis shows that females are 2.1 times more prone to infections among cases as compared to healthy individuals [unadjusted OR 2.20, 95 % confidence interval (CI) 1.5-10.6, p = 0.02; adjusted OR 2.1, 95 % CI 1.50-10.69, p = 0.02]. We propose that patients receiving intradermal were less likely to be infected as compared to those receiving intralesional injections [unadjusted OR 0.07.0, 95 % confidence interval (CI) 1.18-3.37, p = 0.03; adjusted OR 0.06, 95 % CI 1.18-3.38, p = 0.03].

CONCLUSION

Old age (adults) and sex (females) were the strongest predictors to be associated with recurrent leishmaniasis. Similarly, the choice of intradermal as compared to intralesional injection and the prolonged treatment duration were strongly associated with greater chances of recurrence.

Determinants of anthroponotic cutaneous leishmaniasis by case-control study in Morocco

Leishmaniasis is endemic in Morocco where both cutaneous and visceral forms coexist. To date, anthroponotic cutaneous leishmaniasis (ACL) determinants remain poorly investigated in Morocco. However, the disease risk factors identification is vital to determine the specific preventive process. In this aim, a case-control study was conducted in the main active ACL foci in central Morocco. Epidemiological data were extracted from bulletins, registers and annual reports of the regional direction of Health offices. The socioeconomic and environmental data were collected from epidemiological surveys, completed by a questionnaire intended for accessible positive population and control people selected from the cases' entourage. The study included 258 cases and 395 controls. Our results showed that many socioeconomic factors were associated with ACL in Morocco such as the rural habitation (OR = 4.163; 95% CI: 2.91-5.96), movement to endemic area (OR = 4.53; 95% CI: 3.03-6.77), provenance from leishmaniasis foci (in Essaouira focus OR = 5.34; 95% CI: 1.19-24.03) and poverty. In addition, environmental factors like proximity of vegetation (OR = 2.45; 95% CI: 1.14-5.25), poor domestic hygiene, particularly the absence of sewage system/waste management (OR = 1.63; 95% CI: 1.35-1.96), and presence of animals (OR = 2.67; 95% CI: 1.14-5.25) increase the risk of ACL in Morocco. Except for Matrimonial status (married people, OR = 4.11; 95% CI: 1.80-9.41), there is however no significant association of the disease with the other socio-demographic factors in the study area (p>0.05). These several risk factors must be taken in consideration to prevent this disease through multidisciplinary collaboration and community participation.

Genotypic and phylogenic analyses of cutaneous leishmaniasis in Al Ahsa, Eastern Saudi Arabia during the coronavirus disease 2019 pandemic: First cases of Leishmania tropica with the predominance of Leishmania major

During the coronavirus disease 2019 lockdown period, a surge in sandflies and cutaneous leishmaniasis (CL) cases was observed in Al-Ahsa, Saudi Arabia. Skin punch biopsies were obtained from 100 patients clinically diagnosed with CL in Al-Ahsa who had no travel history in the last 6 months. Impression smears were used following a three-step polymerase chain reaction (PCR) protocol using genus-specific primers targeting kDNA and ITS1. Leishmania speciation was determined by ITS1 PCR/nested PCR-restriction fragment length polymorphism and sequencing. A phylogenetic tree was constructed. The associated patient characteristics were analyzed. Using internal transcribed spacer one (ITS1)-PCR/nested PCR, 98 cases were considered true-positive CL. Leishmania major was the predominant species, and Leishmania tropica was identified in three cases. Microscopy had poor sensitivity and perfect specificity. Direct ITS1-PCR missed nine cases. Sex, residence, and treatment outcome were significantly associated with the occurrence of Leishmania; distribution of skin lesion(s) and treatment outcome were significantly associated with Leishmania genotype. This is the first time that L. tropica was identified as a cause of CL in human in Al-Ahsa, in addition to the predominant zoonotic species, L. major. We recommend using ITS1-nested PCR for negative cases by ITS1-PCR. Further exploration of Leishmania transmission dynamics in vectors and reservoir animals is essential for designing effective preventive measures.

Persistence and Changing Distribution of Leishmaniases in Kenya Require a Paradigm Shift

BACKGROUND

Leishmaniases present a major global public health problem, being responsible for between 40,000 and 50,000 deaths annually. The resultant morbidity affects the economic productivity and quality of life of individuals in endemic regions. As zoonotic disease(s), leishmaniases have become persistent with intermittent transmission and a tendency to disappear and reemerge, straining the fragile healthcare infrastructure in Kenya. There is a need to better understand disease(s) dynamics in Kenya. Objectives of the study. The status of leishmaniases in Kenya was reviewed to refocus and influence the attention of the scientific community and intervention strategies/policies on this persistent public health problem. Methodology. Electronic and manual literature were searched for relevant scholarly peer-reviewed published articles on leishmaniases. Literatures were obtained from PubMed, Medline, EBSCO, Host, ScienceDirect, and Google Scholar. Findings. The diseases are reported to be persistent as emerging and reemerging within and outside traditional endemic regions. Cutaneous leishmaniasis (CL) has maintained restricted foci in Nyandarua, Baringo, Nakuru counties, and Mount Elgon area in Bungoma County. Visceral leishmaniasis (VL) was most prevalent with cases in Baringo, Turkana, West Pokot, Isiolo, Kitui, Meru, Machakos, Marsabit, and Wajir counties. New VL cases/foci reported in formerly nonendemic regions/beyond traditional foci of Garissa and Mandera counties. Diagnostics, management, and control strategies have remained unchanged even in the face of changing disease epidemiology.

CONCLUSION

Leishmaniases are emerging and reemerging persistent infections in remote rural settings in Kenya. The adopted intervention strategies have not been effective over the years, and this has led to disease spread to formerly nonendemic areas of Kenya. The diseases spread have been further enhanced by population growth and movement, environmental and climate changes, and social conflicts. It is evident that without a paradigm shift in control methods, diagnostic techniques, and treatment protocols, the diseases may spread to even more areas in the country.

From infection to vaccination: reviewing the global burden, history of vaccine development, and recurring challenges in global leishmaniasis protection

INTRODUCTION

Leishmaniasis is a major public health problem and the second most lethal parasitic disease in the world due to the lack of effective treatments and vaccines. Even when not lethal, leishmaniasis significantly affects individuals and communities through life-long disabilities, psycho-sociological trauma, poverty, and gender disparity in treatment.

AREAS COVERED

This review discusses the most relevant and recent research available on Pubmed and GoogleScholar highlighting leishmaniasis' global impact, pathogenesis, treatment options, and lack of effective control strategies. An effective vaccine is necessary to prevent morbidity and mortality, lower health care costs, and reduce the economic burden of leishmaniasis for endemic low- and middle-income countries. Since there are several forms of leishmaniasis, a pan-Leishmania vaccine without geographical restrictions is needed. This review also focuses on recent advances and common challenges in developing prophylactic strategies against leishmaniasis.

EXPERT OPINION

Despite advances in pre-clinical vaccine research, approval of a human leishmaniasis vaccine still faces major challenges - including manufacturing of candidate vaccines under Good Manufacturing Practices, developing well-designed clinical trials suitable in endemic countries, and defined correlates of protection. In addition, there is a need to explore Challenge Human Infection Model to avoid large trials because of fluctuating incidence and prevalence of leishmanasis.

Cutaneous Leishmaniasis in Pakistan: a neglected disease needing one health strategy

Background

Cutaneous Leishmaniasis (CL) is a neglected tropical disease, which mainly affects poor communities. It is one of the major vector-borne disease and endemic in Pakistan.

Methods

A case-control study to evaluate potential risk factors of human-CL was conducted in Khewra region, District Jhelum, Pakistan from January–April 2014. Case data about 90 cases registered during October 2012 to November 2013 was retrieved from Municipal Hospital. Controls were matched (1,1 ratio) on the date of registration with cases from same hospital. Both cases and controls were invited to participate and data was collected in a face-to-face interview. A prospective study of canine leishmaniasis (canine-CL) was also conducted at Civil Veterinary Hospital in the same area. Suspected dogs with skin ulceration signs were included in the study and blood samples were collected. Statistical analyses were conducted to determine association between various parameters and outcome of interest.

Results

The ages of cases ranged from 1 to 76 years (median = 15 years) and proved to be protective factor i.e. increase in each year in age reduced the likelihood of being infected with human-CL [Odds Ratio (OR) = 0.4, 95% Confidence Interval (CI) = 0.25–0.76]. People sleeping outsides in an open area were more likely to become a case (OR = 8.7, 95% CI = 2.90–26.37) than a control. Poor sanitary condition inside the house (OR = 3.3, 95% CI 1.03–10.56) and presence of other animals in house (livestock, poultry) (OR = 3.6, 95% CI = 1.07–12.12) also identified as risk factors of high significance. The proportion of positive dogs with canine-CL was 21.05% and was significantly associated with human-CL cases in the same area (p < 0.05).

Conclusions

We concluded that adopting self-protections measures against sand-fly, and maintaining good hygiene may lower the risk of human-CL. One-Health Strategy is suggested to control leishmaniasis in human and dog population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06327-w.

Cutaneous Leishmaniasis Outbreak Investigation in Hajjah Governorate, Yemen, in 2018: Case-Control Study

Background

Cutaneous leishmaniasis (CL) is endemic in Yemen. About 4440 cases were reported in 2019. On July 23, 2018, a Hajjah governorate surveillance officer notified the Ministry of Public Health and Population about an increase in the number of CL cases in Bani-Oshb, Kuhlan district, Hajjah governorate. On July 24, 2018, Yemen Field Epidemiology Training Program sent a team to perform an investigation.

Objective

We aimed to describe a CL outbreak in Hajjah governorate and determine its risk factors.

Methods

A descriptive study and case-control study (1:1 ratio) were conducted. Cases included people who met the suspected or confirmed case definition of the World Health Organization and lived in Bani-Oshb subdistrict during the period from August 2017 to July 2018. Controls included people living for at least 1 year in Bani-Oshb without new or old skin lesions. Crude odds ratios (cORs) and adjusted odds ratios (aORs) with 95% CI were used to test the significance of associations.

Results

We identified 30 CL cases. Among the 30 patients, 7 (23%) were younger than 5 years, 17 (57%) were 5 to 14 years, 17 (57%) were females, and 23 (77%) had one lesion. The attack rate was 7 per 1000 population in the age group <15 years and 1 per 1000 population in the age group ≥15 years. On bivariate analysis, the following factors were significantly associated with CL: female gender (cOR 5.2, 95% CI 1.7-16.5), malnutrition (cOR 5.2, 95% CI 1.7-16.5), not using a bed net (cOR 14.5, 95% CI 1.7-122.4), poor house lighting (cOR 6.4, 95% CI 2.1-19.7), poor house hygiene (cOR 11.2, 95% CI 3.1-40.7), poor sanitation (cOR 14.5, 95% CI 1.7-122.4), living in houses without window nets (cOR 5.2, 95% CI 1.3-21.2), plantation around the house (cOR 6.5, 95% CI 2.1-20.5), animal barn inside or close to the house (cOR 9.3, 95% CI 1.9-46.7), raising animals (cOR 8.1, 95% CI 1.6-40.7), and having animal dung in or near the house (cOR 6.8, 95% CI 1.7-27.7). The following risk factors remained significant on multivariate stepwise analysis: female gender (aOR 22.7, 95% CI 1.6-320.5), malnutrition (aOR 17.2, 95% CI 1.3-225.8), poor house hygiene (aOR 45.6, 95% CI 2.5-846.4), plantation around the house (aOR 43.8, 95% CI 1.9-1009.9), and raising animals (aOR 287.1, 95% CI 5.4-15205.6).

Conclusions

CL was endemic in Hajjah governorate, and an increase in cases was confirmed. Many individual, housing, and animal related factors were shown to contribute to CL endemicity. Implementation of control measures directed toward altering the factors favoring contact among vectors, reservoirs, and susceptible humans is strongly recommended to control future outbreaks.

Leishmaniasis Beyond East Africa

Climate change is having a substantial impact on our environment and ecosystems and has altered the way humans live, access, and utilize resources with increased risk of zoonotic infectious disease encounters. As global temperatures continue to increase, they impact on public health, migration, food security and land conflict, and as new environments become favorable, exposure to disease carrying vectors. Increased forests or natural habitat clearance for land repurposing, urbanization, road building, and water management are related to an increase in emerging vector borne parasitic diseases. The East African region remains one of the most impacted regions globally for leishmaniasis, a vector borne disease that impacts significantly on the health, wellbeing and livelihoods of affected communities and for which a lack of reporting and control interventions hinder progress toward elimination of this neglected tropical disease. As our world continues to transform, both politically and climatically, it is essential that measures are put in place to improve surveillance and disease management with implementation of control measures, including vector control, especially in low- and middle-income countries that are expected to be most impacted by changes in climate. Only through effective management, now, can we be sufficiently resilient to preventing the inevitable spread of vectors into suitable habitat and expansion of the geographical range of leishmaniasis. This review offers a current perspective on Leishmaniasis as an endemic disease in East Africa and examines the potential of the recent emergence of Leishmania infection in hitherto unaffected regions to become a public health concern if no disease management is achieved.

A long-lasting emerging epidemic of anthroponotic cutaneous leishmaniasis in southeastern Iran: population movement and peri-urban settlements as a major risk factor

Background

Epidemics of cutaneous leishmaniasis (CL) are occurring more frequently and spreading faster and farther than before in many areas of the world. The present study aimed to assess a long-lasting emerging epidemic (2005–2019) of 5532 cases with anthroponotic CL (ACL) in peri-urban areas of Kerman city in southeastern Iran.

Methods

This descriptive-analytical study was carried out for 15 years in Kerman province, southeastern Iran. The data were passively obtained through the health surveillance system and the Kerman Leishmaniasis Research Center. Every subject was diagnosed using direct smear microscopy. The representative causative agent was further examined by ITS1-PCR, PCR-RFLP, 7SL RNA gene sequencing and phylogenetic analyses. For each subject, a case report form designating demographic and clinical data was recorded.

Results

A different pattern of ACL incidence was found in peri-urban areas compared to that in the city of Kerman. The incidence rate of ACL cases has significantly increased (P < 0.001) from 2005 to 2016 in new settlements with a gradual decline after that. The overall average risk of contracting the disease was 7.6 times higher in peri-urban areas compared to Kerman city, an old endemic focus. All isolates consisting of six variants were confirmed to be Leishmania tropica. The overall pattern of the ACL infection indicates that the etiological agent of ACL is propagated and transmitted by the bite of female Phlebotomus sergenti sandflies from person to person from dissimilar clones as reflected by the complexity of the migrants’ backgrounds in the province.

Conclusions

The movement of populations and establishment of new settlements in peri-urban areas close to endemic areas are major risk factors for and are directly linked to CL. The underlying factors of this emerging ACL epidemic caused by L. tropica were disasters and droughts, among others. A robust commitment to a multilateral approach is crucial to make improvements in this area. This will require decisive coordinated actions through all governmental factions and non-governmental organizations. Furthermore, active and passive case detection strategies, early diagnosis, and effective treatment could help control the disease.

Exploring the influence of different habitats and their volatile chemistry in modulating sand fly population structure in a leishmaniasis endemic foci, Kenya

Phlebotomine sand flies transmit many viral protozoan and bacterial pathogens of public health importance. Knowledge of the ecologic factors influencing their distribution at local scale can provide insights into disease epidemiology and avenues for targeted control. Animal sheds, termite mounds and houses are important peri-domestic and domestic habitats utilized by different sand flies as resting or breeding habitats. However, our knowledge for selection of these habitats by sand flies remains poor. Here, we tested the hypothesis that these habitat types harbor different composition of sand fly species and differ in their volatile chemistry that could influence sand fly selection. To achieve this, we employed CDC light traps following a cross-sectional survey to investigate the distribution of sand flies in the three habitats in an endemic site for leishmaniasis in Kenya. The study was carried out during the dry season, when sand flies are optimally abundant in 2018 and 2020. Sand fly abundance did not vary between the habitats, but species-specific differences in abundance was evident. Measures of sand fly community structure (Shannon diversity and richness) were highest in animal shed, followed by termite mound and lowest inside human dwelling (house). This finding indicates broader attraction of both sexes of sand flies and females of varying physiological states to animal sheds potentially used as breeding or resting sites, but also as a signal for host presence for a blood meal. Furthermore, gas chromatography-mass spectrometric analysis of volatiles collected from represented substrates associated with these habitats viz: human foot odor on worn socks (houses indoors), cow dung (animal sheds) and termite mounds (enclosed vent), revealed a total of 47 volatile organic compounds. Of these, 26, 35 and 16 were detected in human socks, cow dung and enclosed termite vent, respectively. Of these volatiles, 1-octen-3-ol, 6-methyl-5-hepten-2-one, α-pinene, benzyl alcohol, m-cresol, p-cresol and decanal, previously known as attractants for sandflies and other blood-feeding insects, were common to the habitats. Our results suggest that habitat volatiles may contribute to the composition of sand flies and highlight their potential for use in monitoring sand fly populations.

Novel IM-associated protein Tim54 plays a role in the mitochondrial import of internal signal-containing proteins in Trypanosoma brucei

BACKGROUND

The translocase of the mitochondrial inner membrane (TIM) imports most of the nucleus-encoded proteins that are destined for the matrix, inner membrane (IM) and the intermembrane space (IMS). Trypanosoma brucei, the infectious agent for African trypanosomiasis, possesses a unique TIM complex consisting of several novel proteins in association with a relatively conserved protein TbTim17. Tandem affinity purification of the TbTim17 protein complex revealed TbTim54 as a potential component of this complex.

RESULTS

TbTim54, a trypanosome-specific IMS protein, is peripherally associated with the IM and is present in a protein complex slightly larger than the TbTim17 complex. TbTim54 knockdown (KD) reduced the import of TbTim17 and compromised the integrity of the TbTim17 complex. TbTim54 KD inhibited the in vitro mitochondrial import and assembly of the internal signal-containing mitochondrial carrier proteins MCP3, MCP5 and MCP11 to a greater extent than TbTim17 KD. Furthermore, TbTim54 KD, but not TbTim17 KD, significantly hampered the mitochondrial targeting of ectopically expressed MCP3 and MCP11. These observations along with our previous finding that the mitochondrial import of N-terminal signal-containing proteins like cytochrome oxidase subunit 4 and MRP2 was affected to a greater extent by TbTim17 KD than TbTim54 KD indicating a substrate-specificity of TbTim54 for internal-signal containing mitochondrial proteins. In other organisms, small Tim chaperones in the IMS are known to participate in the translocation of MCPs. We found that TbTim54 can directly interact with at least two of the six known small TbTim proteins, TbTim11 and TbTim13, as well as with the N-terminal domain of TbTim17.

CONCLUSION

TbTim54 interacts with TbTim17. It also plays a crucial role in the mitochondrial import and complex assembly of internal signal-containing IM proteins in T. brucei.

SIGNIFICANCE

We are the first to characterise TbTim54, a novel TbTim that is involved primarily in the mitochondrial import of MCPs and TbTim17 in T. brucei.