Journal of Arthropod-Borne Diseases
Volume:14 Issue: 4, Dec 2020

Malaria has long been regarded as one of the most important public health issues in Iran. Although the country is now in the elimination phase, some endemic foci of malaria are still present in the southeastern areas of the country. In some endemic foci, there are no data on the malaria vectors. To fill this gap, the present study was designed to provide basic entomological data on malaria vectors in the southeastern areas of Iran.

Adult and larval stages of Anopheles mosquitoes were collected by using different catch methods. Resistance of the main malaria vector in the study area to selected insecticides was evaluated using diagnostic doses advised by the World Health Organization in 2013–2014.

A total of 3288 larvae and 1055 adult Anopheles mosquitoes were collected, and identified as: Anopheles ste phensi (32.1%), Anopheles culicifacies s.l. (23.4%), Anopheles dthali (23.2%), Anopheles superpictus s.l. (12.7%), and Anopheles fluviatilis s.l. (8.6%). Anopheles stephensi was the most predominant mosquito species collected indoors at the study area, with two peaks of activity in May and November. This species was found to be resistant to DDT 4%, tolerant to malathion 5% and susceptible to other tested insecticides.

All the five malaria vectors endemic to the south of Iran were collected and identified in the study area. Our findings on the ecology and resting/feeding habitats of these malaria vectors provide information useful for plan ning vector control program in this malarious area.

Insecticide resistance is one of the most important problems associated with the control of Musca domes tica, due to the potential of the rapid development of resistance to different chemical insecticides. The present study was carried out to evaluate dichlorvos resistance in the house fly populations collected from central regions of Iran, Isfahan Province and Chaharmahal and Bakhtiari Province, during 2017 to 2019.

Bioassays were carried out using a standard topical application method as well as a fumigation method. The Koohrang population (susceptible) with the lowest LD50 values to dichlorvos was chosen to calculate the resistance rati os (RR). Altered sensitivity of acetylcholinesterase (AChE), a target enzyme for dichlorvos, was investigated.

According to the results, very high levels of dichlorvos resistance were observed in the Mobarake population (RR= 80.25-fold by topical application and 33-fold by fumigation bioassay), and Isfahan population (RR= 107.30-fold by topical application and 43-fold by fumigation bioassay) compared to the Koohrang population. Acetylcholinesterase of the Koohrang population was the most sensitive to inhibition by dichlorvos based on the determination of median inhibitory concentration (IC50), but AChE of Mobarake and Isfahan populations were 741.93- and 343.94- fold less sen sitive to inhibition.

The insensitivity of AChE was possibly involved in dichlorvos resistance in the house fly populations.

Asymptomatic malaria, which usually exists in low parasitemia, acts as the Plasmodium species reser voirs contributing towards malaria transmission. This situation hinders malaria elimination programs in endemic areas, thus necessitating an active case detection with a high sensitive method and treatment of cases. This is why we used a High Resolution Melting (HRM) assay to monitor the trend of asymptomatic malaria in a malaria endemic area of Iran which is under elimination program.

The peripheral blood was sampled from 271 clinically approved non-febrile individuals from a malaria en demic zone of southeastern Iran for asymptomatic malaria prevalence detection by microscopy, Rapid Diagnostic Tests (RDTs) and HRM methods. The HRM assay was done based on the amplification of 18S SSU rRNA gene.

The HRM assay revealed infections from three individuals out of 271 (1.1% asymptomatic malaria prevalence) from the participants, two Iranian natives with Plasmodium vivax infection and one Pakistani immigrant with P. falcipa rum infection. Neither microscopy nor RDTs detected Plasmodium spp infections from the 271 non-febrile individuals. The nucleotide sequencing analysis of the positive controls used in this study showed a close homology with the refer ence gene bank sequences of P. falciparum 3D7 (CPO16995.1) and P. vivax Sal-1(UO3079.1).

This study revealed a low frequency of asymptomatic malaria trend within malaria endemic areas of southeastern Iran which are under intense elimination program and also the ability of HRM assay in detecting low Plasmodium spp parasitemia beyond the limits of microscopy and RDTs.

Cutaneous leishmaniasis (CL) is a vector borne disease predominantly found in tropical and subtropical countries, including Iran. For more than 6 decades, pentavalent antimonials have been used successfully worldwide for the treatment of leishmaniasis, but over the past few years, clinical resistance to these medications has increased. In this study, we evaluated CL patients who did not show any desirable responses to the anti-leishmanial treatment within a 10-year period (2008 to 2017).

All patients from different parts of Iran suspected of having cutaneous leishmaniasis, who were referred to the laboratory of leishmaniosis in Tehran University of Medical Sciences from 2008–2017 were parasitological exam ined.

During this period, a total of 1480 suspected CL patients were referred to the laboratory of leishmaniosis. Samples from 655 patients (70.8%) suspected of having CL were positive microscopically. The failure rate in patients treated with anti-leishmaniasis medications for a minimum of three complete treatment periods was 1.83% (12 cases). There was no association between the number and size of skin lesions and patient characteristics. Also, the route of drug administration had no significant effect on the number and size of lesions.

In the present study, treatment failure was found in some confirmed CL patients treated with meglu mine antimoniate. Over the past few years, it seems that had been increased in resistance to these medications. So, a review of the correct implementation of the treatment protocol and/or a combination therapy may be helpful in prevent ing an increase in the rate of treatment failure.

Southeastern Iran has been established as an area with the potential to harbor Asian tiger mosquito popu lations. In 2013, a few numbers of Aedes albopictus were detected in three sampling sites of this region. This field study was aimed to evaluate the efficacy of various traps on monitoring mosquitoes and status of this dengue vector, in five urban and 15 suburban/rural areas.

For this purpose, four adult mosquito traps (BG-sentinel 2, bednet, Malaise, and resting box trap) were used and their efficacy compared. In addition, large numbers of CDC ovitraps were employed, within 12 months.

A total of 4878 adult samples including 22 species covering five genera were collected and identified from traps. It was not revealed any collection of Ae. albopictus. Statistical analysis showed no significant difference in mete orological variables between the two periods, the previous report and the current study. There were significant differ ences in the total number of mosquitoes collected by various traps in the region across different months.

The resulting data collected here on the efficiency of the various trap types can be useful for monitoring the densities of mosquito populations, which is an important component of a vector surveillance system. While the pres ence of Ae. albopictus was determined in this potential risk area, there is no evidence for its establishment and further monitoring needs to be carried out.

Derris elliptica extracts have a high larvicidal potential against the laboratory strain of Aedes aegypti larvae, but the effect on offspring larvae of pyrethroid-resistant strains of the species is lack understood. This study aimed to determine the larvicidal activity of the ethyl acetate extract of tuba root against the third-instar larvae of the Cypermethrin-resistant Ae. aegypti offspring.

The experimental study occupied four levels of ethyl acetate extract of D. elliptica namely 10, 25, 50, and 100 ppm, and each level was four times replicated. As many as twenty of healthy third-instar larvae, offspring of Cy permethrin-resistant Ae. aegypti were subjected to each experiment group. Larval mortality rate and lethal concentration 50% subject (LC50) were calculated after 24 and 48 hours of exposure time.

Mortality of larvae increased directly proportional to the increase of extract concentration. Larval mortality rates after 24 and 48 hours of exposure were 40–67.5% and 62.5–97.5%, and LC50 were 34.945 and 6.461ppm, respec tively.

The ethyl acetate extract of D. elliptica has the high effectiveness larvicidal potential against the third-instar larvae, offspring of the Cypermethrin-resistant Ae. aegypti. Isolation of the specific compound is necessarily done to obtain the active ingredient for larvicide formulation.

Crimean–Congo hemorrhagic fever (CCHF) is a fatal disease caused by Nairovirus classified within the Bunyaviridae family. The virus is transmitted to humans through the bites of infected ticks or direct contact with viremic animals or humans. The current study aimed to detect the virus genome in ticks from Khorasan Razavi Province.

One hundred hard ticks were collected randomly from 100 sheep in four different areas of the province. Collected ticks were kept alive and identified. All the ticks were analyzed for the presence of CCHF virus genome using reverse transcriptase polymerase chain reactions (RT-PCR).

The identified ticks were belonging to Hyalomma marginatum (16% female and 6% male), Rhipicephalus turanicus (52% female and 25% male), and Dermacentor raskemensis (1%). The CCHF virus genome was found in Hyalomma marginatum (5% male from Taibad and Sabzevar region and 1% female from Taibad). Genetic analysis of the virus genome isolated from two regions (Sabzevar and Taibad) showed 100% identity.

This study indicated that CCHF should be regarded as a risk-borne infection in this province. Therefore, special health management is needed to control this disease.

The aims of this study were to evaluate the efficiency of two capture methods for providing live sandflies used for determining the susceptibility level of Phlebotomus papatasi, the main vector of zoonotic cutaneous leishmani asis in Lorestan Province, west of Iran.

The sand flies were collected from indoor and outdoor by hand-catch and baited traps during the peak of sea sonal activity. The susceptibility level of sand flies was assessed using insecticide-impregnated papers against DDT 4%, bendiocarb 0.1%, permethrin 0.75%, deltamethrin 0.05%, and cyfluthrin 0.15%.

A total of 2486 live sandflies were caught from both indoor and outdoor places. Totally 849 sand flies were caught from outdoors with a sex ratio(SR) 0.1 versus 1637 sand flies collected from indoor using the hand-catch method with SR= 0.6. The dominant species of sand flies was Ph. papatasi in the study area. Mortality rates of outdoor-col lected sand flies were exposed to DDT 4%, deltamethrin 0.05%, permethrin 0.75%, and bendiocarb 0.1%, and mortality rate ranged from 92.0–97.9% and for indoor-collected sand flies were 87.7–96.8%. Both outdoor and indoor collected sand flies were susceptible to cyfluthrin 0.15% that caused 100% mortality.

Based on the findings, the most appropriate method for collecting the live female Ph. papatasi is the baited traps due to providing enough females is necessary for conducting the susceptibility tests. The finding indicated that Ph. papatasi was resistant to DDT, under ’verification required’ status to deltamethrin, permethrin, bendiocarb, and susceptible to cyfluthrin.

Flesh flies (Diptera: Sarcophagidae) are considered as myiasis agents and important evidences in forensic investigations. However, their use has been restricted because, at all larval stages and female adults, morphological species identification is difficult or very challenging. This study investigated to test utility of mitochondrial cytochrome oxidase subunit I (mt-COI) sequences for differentiation of six forensically important Iranian flesh flies namely, Sarcophaga crassipalpis, S. flagellifera, S. hirtipes, S. aegyptica, S. africa and S. argyrostoma.

Male specimens were morphologically identified to species level and then the genomic DNA of the flies were extracted and subjected to polymerase chain reaction (PCR) against mt-COI gene. The PCR products were sequenced and the obtained sequences were analyzed for the species specific restriction fragment length polymorphisms (RFLPs).

Rate of genetic variation between species was 6–10% which was enough to find restriction enzymes (RE) that were able to produce species-specific RFLP profiles. Combinations of three REs: BsrFI, RsaI and HinfI, provided diagnostic bands for identification of the six Sarcophaga species.

The results of this study showed that molecular markers such as RFLPs enhancing the use of evidence from flesh flies in forensic investigation. However, lack proper restriction sites in the COI region inhibited introduction of a single restriction enzyme for easy species identification. It is recommended to apply larger part of DNA such as combination of COI and COII genes to provide better RFLP markers for species identification of flesh flies.

Myiasis is a disease caused by infections of tissues and organs of human and vertebrates body by the lar vae of real flies of Diptera which feeding on living or dead tissues of host for a period of time. This report aims to pre sent a case of urogenital myiasis caused by the larvae of Psychoda albipennis (Diptera: Psychodidae) for the first time in Iran.

In this case report, we present a case of a 9-year-old girl with urogenital myiasis caused by P. albipennis. She presented to Sina Hospital with dysuria and claimed that he had observed several black-grayish colored mobile particles in his urine at different times. The patient lived in Miandoab, West Azerbaijan Province, Iran.

In the hospital her urine sample, containing 3 larvae was referred to Entomology lab of the Medical Faculty for identification and characterization. According to morphological factors, the larvae were identified to approximate size of 8–10mm long, white to gray color, thorns and pale scales and a siphon at the posterior end of the body. By compar ing the larvae with the reported ones from Turkey, diagnosis was confirmed.

According to our survey, this is the first observation of urogenital myiasis in East Azerbaijan Province, Iran. Our case illustrates urogenital myiasis caused by P. albipennis in Iran. Urogenital myiasis has not been previously reported from Iran as a human disease.