Real-time impact of COVID-19 pandemic on cutaneous leishmaniasis case finding and strategic planning, preventive interventions, control and epidemiology in a region with a high burden of cutaneous leishmaniasis and COVID-19: A cross-sectional descriptive study based on registry data in Ilam-Iran

Background and Aims

Cutaneous leishmaniasis (CL) is a severe parasitic disease affecting people, mostly in underdeveloped nations. As a zoonotic infection yearly incidence of CL depends on several parameters such as demographic, epidemiological, and environmental factors as well as prevention and control measures. The sudden outbreak of pandemics such as SARS-Corona-Virus-2 pandemic, can probably affect the incidence or reporting of other diseases, especially infectious diseases, in various ways such as pressure on health systems, providing sanitary services and its components, lockdowns and changes in people's living habits.

Aim

This study aimed to evaluate the COVID-19 impact on the incidence and other epidemiological aspects as well as control measures of CL in Ilam Province-Iran.

Methods

Required data was extracted from the CL registration system in Ilam from 2014 to 2021 to demonstrate the trend of CL incidence before and after COVID-19 pandemic.

Results

Based on our results, a declining pattern of CL incidence was observed, accompanied by the advent and intensification of the viral pandemic in Iran and Ilam province. Although, this decreasing pattern was not integral in all areas, and even increase in CL detection was emphasized in some regions.

Conclusion

It may be inferred that the COVID-19 pandemic may disrupt treatment programs of CL cases, rodent nest destruction, and fighting vector insects.

In vitro antileishmanial activity of hydroalcoholic Thymbra spicata extract on Leishmania major promastigotes

Cutaneous leishmaniosis is a major worldwide public health problem with annual incidence of 1.5 million cases across 98 countries. Treatment still relies on the use of chemical drugs with increasing resistance and side effects. The aim of this study was to investigate the anti-leishmanial effect of the hydroalcoholic Thymbra spicata extract on Leishmania major (L. major) promastigotes. In this study, 1×105 L. major promastigotes were cultured in 96-well plates and treated with different concentrations of hydroalcoholic T. spicata extract (12.5 to 400 μg/ml) then incubated at 25°C for 24, 48 and 72 hours. Lethal percentage of promastigotes in each well was determined. RPMI 1640 medium containing L. major promastigotes with glucantime or without any treatment were used as positive and negative controls respectively. The 50% lethal concentration (LC50) of T. spicata extract and glucantime was calculated by GraphPad Prism software. The results indicated a significant decrease in the number of promastigotes treated with T. spicata extract and glucantime in comparison with negative control (P<0.0001). LC50 values for T. spicata extract were 18.49, 8.58, and 1.64 μg/ml after 24, 48 and 72 hours, respectively. In addition, anti-leishmanial effect of T. spicata extract and glucantime were dependent on concentration (P<0.0001). Our study revealed T. spicata extract as an herbal product against L. major promastigotes. However, more investigations are needed to find its antileishmanial activity in vivo and clinical trial studies.

Global seroprevalence of Toxoplasma gondii in Camelidae: A systematic review and meta-analysis

PURPOSE

The present study aimed to analyze data available of the seroprevalence of Toxoplasma gondii (T. gondii) among camelids around the world.

METHODS

The search was performed using seven international databases including Scopus, PubMed, Google Scholar, ProQuest, ScienceDirect, Web of Science, and EMBASE up to 11 October 2018. Random effects model was used to determine the pooled seroprevalence of T. gondii infection with 95% confidence intervals (CI) and analyzed data from four continents. Subgroup and meta-regression analyses were also performed according to continent and gender.

RESULTS

In total, 42 studies out of 3517 published articles involving 14,542 camels from 17 countries were included for the final analyses. The global pooled seroprevalence of T. gondii infection in the Camelidae family was 28.16% (95% CI 23.64-32.68%). Besides, the highest seroprevalence rate was in Europe (49.64%) followed by Africa (37.63%), America (21.76%), and Asia (17.58%). Moreover, the overall seroprevalence rates of T. gondii infection were 22% (95% CI 10-33%) and 15% (95% CI 9-22%) for the females and males, respectively.

CONCLUSION

This meta-analysis showed a high seroprevalence of T. gondii infection in camelids as these animals play an important role in the transmission cycle of this zoonotic disease.

Efficacy of Capparis spinosa Linn Leaf and Fruit Extracts on Giardia Lambia Cysts In vitro

Aims: Giardia lamblia (G. lamblia) is one of the most common intestinal parasites worldwide. There are some side effects and the reports of parasite resistance to metronidazole as the first line treatment of giardiasis. Therefore, it is essential to discover an effect and safe drug to treat giardiasis. Methodology: In this study, the anti-parasitic activity of hydroalcoholic extracts of Capparis spinosa Linn (C. spinosa) leaves and fruits with different concentrations (4 to 0.125 mg/ml) was assessed against human isolates of the G. lamblia cysts and incubated at 37℃. After staining Giardia cysts with 0.1% eosin, the lethal percentage and 50% lethal concentration (LC50) of fruit and leave C. spinosa L extracts and metronidazole on G. lamblia cysts were calculated after 3, 6, 24 and 48 hours. Results: Anti-giardia activity of fruit and leaf extracts of C. spinosa was different between concentrations and time points (p<0.005). The lethal effect of both C. spinosa L extracts and metronidazole increased significantly in a concentration - and time–dependent response (P<0.0001). The highest lethal percentage of G. lamblia cysts was observed a concentration of 4 mg / ml of fruit (100%) and leaf (44%) extracts of C. spinosa L after 48 hours, respectively. LC50 values were 0.38 ± 0.02mg/ml for fruit extract, 2.32 ± 0.1 mg/ml for leaf extract and 0.53 ± 0.03 µg/ml for metronidazole after 48hours. Conclusion: C. spinosa can be effective in eliminating Giardia cyst of contaminated environments and water.

A historical review of the role of cytokines involved in leishmaniasis

Leishmaniasis is an infectious disease caused by the Leishmania genus, affecting millions of persons in the world. Despite increased studies, no vaccine has been developed against leishmaniasis, and drug resistance is evolving in some Leishmania species (spp). Innate and acquired immune cells and their associated cytokines interplay together to determine the immune responses related outcomes in leishmaniasis. Interferon (IFN)-γ or macrophage activating factor (MAF) is the first effective lymphokine (LK), with a related function to leishmaniasis, discovered in 1979. This review article discussed the history of cytokines involved in Leishmania infection, and it is the first report demonstrating the involvement in the disease by focusing on cutaneous leishmaniasis. Up to now, the role of many cytokines has been determined and the literature review showed that IL-35 is the latest known cytokine involved in leishmaniasis. This review revealed that the cytokines have pleiotropic effects, depending upon the cytokine environment, generated during the infection and the host genetic background or infecting Leishmania spp. Overall, advances in our knowledge of immune cells and their secreted cytokines, contributing to the protection or pathological process of leishmaniasis may help to reach new approaches for immunotherapy.

DNA vaccination with a plasmid encoding LACK-TSA fusion against Leishmania major infection in BALB/c mice

Vaccination would be the most important strategy for the prevention and elimination of leishmaniasis. The aim of the present study was to compare the immune responses induced following DNA vaccination with LACK (Leishmania analogue of the receptor kinase C), TSA (Thiol-specific-antioxidant) genes alone or LACK-TSA fusion against cutaneous leishmaniasis (CL). Cellular and humoral immune responses were evaluated before and after challenge with Leishmania major (L. major). In addition, the mean lesion size was also measured from 3th week post-infection. All immunized mice showed a partial immunity characterized by higher interferon (IFN)-γ and Immunoglobulin G (IgG2a) levels compared to control groups (p<0.05). IFN-γ/ Interleukin (IL)-4 and IgG2a/IgG1 ratios demonstrated the highest IFN-γ and IgG2a levels in the group receiving LACK-TSA fusion. Mean lesion sizes reduced significantly in all immunized mice compared with control groups at 7th week post-infection (p<0.05). In addition, there was a significant reduction in mean lesion size of LACK-TSA and TSA groups than LACK group after challenge (p<0.05). In the present study, DNA immunization promoted Th1 immune response and confirmed the previous observations on immunogenicity of LACK and TSA antigens against CL. Furthermore, this study demonstrated that a bivalent vaccine can induce stronger immune responses and protection against infectious challenge with L. major.

Pro- and anti-inflammatory cytokines in cutaneous leishmaniasis: a review

Cutaneous leishmaniasis (CL) is caused by different species of the genus Leishmania. Pro- and anti-inflammatory cytokines play different roles in resistance/susceptibility and the immunopathogenesis of Leishmania infection. The balance and dynamic changes in cytokines may control or predict clinical outcome. T helper 1 (Th1) inflammatory cytokines (especially interferon-γ, tumor necrosis factor-α and interleukin-12) are the crucial factors in the initiation of protective immunity against L. major infection, whereas T helper 2 cytokines including IL-5, IL-4, and IL-13 facilitate the persistence of parasites by downregulating the Th1 immune response. On the other hand, aggravation of inflammatory reactions leads to collateral tissue damage and formation of ulcer. For this reason, immunity system such as T regulatory cells produce regulatory cytokines such as transforming growth factor-β and IL-10 to inhibit possible injures caused by increased inflammatory responses in infection site. In this article, we review the role of pro- and anti-inflammatory cytokines in the immunoprotection and immunopathology of CL.