Visceral leishmaniasis among children in an endemic area of northwestern Iran between 2016 and 2017: An epidemiological study

Objective: To clarify the epidemiological aspects of visceral leishmaniasis in Kaleybar and Khoda-Afarin districts, north-west of Iran.Methods: A total of 1 420 human(children under 12 years) samples, 101 domestic dogs samples(Canis familiaris), and 577 female sand fly samples were collected. Sera of human and dogs were tested using the direct agglutination test, and sand flies were identified at species level using the microscopic method. Furthermore, a structured questionnaire was applied to evaluate the correlation between the potential risk factors and the related clinical signs/symptoms with the human and dogs’ seropositivity.Results: Totally, 2.18% of human samples were positive at titers≥1: 800;among them, 13 cases(41.94%) were above 1:3 200, and clinical symptoms were observed in all of them except for an 11-year old girl. Anti-Leishmania infantum antibodies were found at titer≥1: 320 in 9.90% of dogs’ samples, half of them had at least one sign of canine visceral leishmaniasis. Moreover, 10 Phlebotomus species were identified in the study areas, and Phlebotomus(Larroussius) major group was the predominant species. There are significant correlations between the presence of anti-Leishmania infantum antibodies and the fever(P<0.001), anemia(P=0.001) and weight loss(P=0.016) in children. On the other hand, significant correlations were revealed between the Leishmania infection and the shelter(P=0.039), cutaneous lesion(P=0.005), lymphadenopathy(P=0.001) and weight loss(P<0.001) in the infected dogs.Conclusions: Visceral Leishmania infection is prevalent in rural areas of Kaleybar and KhodaAfar districts located in East-Azerbaijan province, therefore active detection and treatment of visceral leishmaniasis cases should not be neglected.

Prediction of malaria cases in the southeastern Iran using climatic variables:An 18-year SARIMA time series analysis

Objective:To predict future trends in the incidence of malaria cases in the southeast of Iran as the most important area of malaria using Seasonal Autoregressive Integrated Moving Average(SARIMA)model,and to check the effect of meteorological variables on the disease incidence.Methods:SARIMA method was applied to fit a model on malaria incidence from April 2001 to March 2018 in Sistan and Baluchistan province in southeastern Iran.Climatic variables such as temperature,rainfall,rainy days,humidity,sunny hours and wind speed were also included in the multivariable model as covariates.Then,the best fitted model was adopted to predict the number of malaria cases for the next 12 months.Results:The best-fitted univariate model for the prediction of malaria in the southeast of Iran was SARIMA(1,0,0)(1,1,1)12[Akaike Information Criterion(AIC)=307.4,validation root mean square error(RMSE)=0.43].The occurrence of malaria in a given month was mostly related to the number of cases occurring in the previous 1(p=1)and 12(P=1)months.The inverse number of rainy days with 8-month lag(β=0.3292)and temperature with 3-month lag(β=-0.0026)were the best predictors that could improve the predictive performance of the univariate model.Finally,SARIMA(1,0,0)(1,1,1)12 including mean temperature with a 3-month lag(validation RMSE=0.414)was selected as the final multivariable model.Conclusions:The number of malaria cases in a given month can be predicted by the number of cases in the prior 1 and 12 months.The number of rainy days with an 8-month lag and temperature with a 3-month lag can improve the predictive power of the model.

In vitro and in vivo susceptibility of Leishmania major to some medicinal plants

Objective: To evaluate the efficacy of some medicinal plants and systemic glucantime in a comparative manner against the causative agent of cutaneous leishmaniasis both in vitro and in BALB/c mice.Methods: For in vivo testing, inbred mice were challenged with Leishmania major parasites and the resultant ulcers were treated with extract based-ointments applied topically two times per day for a period of 20 days. A group of 56 mice were randomly divided into 7 subgroups. The control group received the ointment void of extracts,whereas the reference group received glucantime only. The efficacy of treatments was evaluated by measuring ulcer diameter, parasite burden and NO production.Results: Our results indicated that plant extract based-ointments were effective in reducing ulcer size and parasite burden in spleens, but their effects did not differ significantly from that of glucantime. The plant extracts tested in this study were able to increase NO production that helped parasite suppression.Conclusions: Our findings indicate that the tested plant extracts are effective against Leishmania major both during in vitro and in vivo experiments, but further researches are required to recommend a potential plant extract as an alternative drug.