Species Composition and Geographic Distribution of Culicinae Mosquitoes and Their Possible Infection with West Nile Virus in Hormozgan Province, Southern Iran.

Background: West Nile virus (WNV) is a mosquito-borne virus that causes a febrile disease and may cause a fatal neurological illness in humans. We aimed to investigate the geographic distribution of Culicinae mosquitoes and their possible infection with WNV in Hormozgan Province, southern Iran. Methods: Field studies were carried out from June 2017 to May 2019. Different mosquito sampling methods were used monthly to collect mosquitoes from 22 sites. The Real-Time PCR technique was used to detect the virus infection in the mosquitoes. Results: Overall, 6165 mosquitoes were caught. The species were Culex theileri (33.25%), Cx. pipiens (20.45%), Cx. quinquefasciatus (10.51%), Aedes caspius (6.33%), Cx. tritaeniorhynchus (5.82%), Ae. vexans (4.10%), Cx. sinaiticus (3.62%), Cx. antennatus (3.29%), Culiseta longiareolata (2.81%), Cx. perexiguus (2.03%), Cs. subochrea (1.95%), Cx. mimeticus (1.49%), Cx. pusillus (1.38%), Cx. univittatus (1.27%), Cx. modestus (1.14%), and Cx. sitiens (0.57%). The molecular detection of virus infection in mosquitoes found to be negative for WNV. Conclusion: The presence of many species of mosquito vectors and high population traffic increase the risk of disease transmission is very high. Therefore, the way to restrict WNV infection factors is increasing the knowledge for personal protection measures to prevent mosquito bites.

Study on Hard and Soft Ticks of Domestic and Wild Animals in Western Iran.

Background: Ticks are blood-sucking ectoparasites of many vertebrates and act as vectors of a wide range of vector-borne diseases. Alongside pathogens transmission, ticks also cause economic losses in animal industry such as production loss, physical damage, anemia, and poisoning. This study aimed to determine the fauna, geographical distribution and seasonal activity of ticks collected from animals in Lorestan Province, west of Iran. Methods: Ticks were collected from domestic animals including cattle, sheep, goats, chickens, turkeys, pigeons, as well as wild animals such as jackals in 2017-2018. Then, they were identified based on morphological characteristics using valid identification keys. Results: Out of a total of 706 ticks, 433 (61.33%), 104 (14.73%), 33 (4.67%) and 136 (19.26%) ticks were collected in spring, summer, autumn and winter, respectively. In terms of hard ticks, 4 genera and 6 species were identified: Hyalomma asiaticum (22.80%), Hyalomma anatolicum (3.68%), Hyalomma marginatum (2.40%), Rhipicephalus sanguineus (0.84%), Dermacentor marginatus (1.13%), and Haemaphysalis sulcata (0.64%). Additionally, two genera and four species fell into soft ticks: Argas persicus (60.48%), Argas reflexus (6.65%), Ornithodoros canstrini (0.70%) and Ornithodoros erraticus (0.42%). There was significant variation in the seasonal activity and abundance of ticks in different seasons but in the tick abundancy among different regions. Conclusion: The present study provides a perspective of the distribution status of ticks in Lorestan Province, their seasonal activity and the likelihood of emergence of related diseases.

Seroprevalence Study on West Nile Virus (WNV) Infection, a Hidden Viral Disease in Fars Province, Southern Iran.

BACKGROUND: West Nile Virus, a mosquito-borne flavivirus, causes a variety of symptoms in human, from asymptomatic infection to neuroinvasive disease. Several studies have been conducted on the seroprevalence of WNV infection in different areas from Iran. This study was performed to find the presence of antiviral antibodies in human serum among some high risk population and awareness of health care staff about symptom of the WNV infection. METHODS: Study performed in five geographical districts based on high population of immigrant and domestic birds and prevalence of the antiviral antibodies in horses which was reported previously. Totally 150 human blood samples were collected during 2018. The samples collected from patients referred to the clinics. The ELISA method used to detect IgG and IgM antibody against WNV. Logistic regression models used to analyze the effect of sex, age, keeping birds and urban/rural residence on the risk of infection. The awareness of health care staff about symptom of infection surveyed. RESULTS: From all blood donors, 41 samples (27.33%) showed positive to IgG antibody. From which 56.10% were males and remaining females. None of the mentioned factors had a significant relationship. Health care staff had less attention to the infection. CONCLUSION: Although the prevalence of antibodies was relatively high, due to the similarity to other viral diseases, health care staff had less attention to the disease. The study showed that people in these areas have been exposed to the virus. Further research activities are recommended for control of this arbovirus.

Biting and resting behaviour of malaria vectors in Bandar-Abbas County, Islamic Republic of Iran.

BACKGROUND: Blood feeding and resting behaviour of malaria vectors are the most influential factors in malaria transmission. AIMS: To measure blood feeding and resting behaviour, conventional mosquito sampling methods were performed in an area with potential for malaria transmission. METHODS: Adult mosquitoes were collected monthly from indoor/outdoor places by conventional sampling methods, and larval habitats were investigated. Enzyme-linked immunosorbent assay was used to measure the human blood index (HBI) of the mosquitoes. RESULTS: Anopheles stephensi, Anopheles culicifacies, Anopheles dthali and Anopheles fluviatilis, were collected. Overall, 1249 female Anopheles mosquitoes were captured on human and animal baits, but no human-vector contact occurred indoors. A. dthali, A. fluviatilis and A. culicifacies showed a greater tendency to outdoor resting places in contrast to A. stephensi, which had a propensity to indoor resting places. The seasonal biting activities of all species occurred at average temperatures between 23 and 27°C. HBI was measured as 27.2%, 20.7%, 19.1%, and 23.0% for A. fluviatilis, A. stephensi, A. culicifacies and A. dthali, respectively. CONCLUSION: Vector control strategy depends upon mosquito behaviour. Therefore, using appropriate sampling methods based on mosquito behaviour is critical for malaria control planning. Exophilic/exophagic habit of mosquito vectors leads to fewer human bites, resulting in biting protection. Exophilic behaviour also requires specific larvicidal operations in order to prevent and control malaria transmission.

Molecular characterization of Ribosomal DNA (ITS2) of hard ticks in Iran: understanding the conspecificity of Dermacentor marginatus and D. niveus.

OBJECTIVES: Hard ticks (Acari: Ixodidae) are ectoparasites of medical and veterinary importance. They are obligate blood-feeding vectors with the ability to transmit a wide variety of pathogens. Standard morphological keys are normally used for the identification of tick species. However, considering the importance of accurate species identification and the determination of bio-ecological characteristics of species, relying on morphological keys alone can be questionable. In this study, two DNA fragments (ITS2 and COI) were selected for phylogenetic evaluation of Iranian hard tick species belonging to the genera Dermacentor, Hyalomma, and Rhipicephalus. RESULTS: 1229 specimens of Dermacentor marginatus, D. niveus, Hyalomma anatolicum, Rhipicephalus bursa, and R. sanguineus s.l constituting 11 populations were collected from three different climatic and zoogeographical zones in Iran. Morphological studies revealed notable differences in important morphological characteristics between different populations of D. marginatus. The results of ITS2 sequence analysis provided additional evidence which supports the conspecificity of D. niveus and D. marginatus. Contrary to this finding, the sequence analysis of COI and phylogeny favored the separation of the two species. Given the greater importance of COI in identifying and discriminating species, a possibility heterospecificity between the two species should be considered.

Ecology of Malaria Vectors in an Endemic Area, Southeast of Iran.

BACKGROUND: 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. METHODS: 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. RESULTS: A total of 3288 larvae and 1055 adult Anopheles mosquitoes were collected, and identified as: Anopheles stephensi (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. CONCLUSION: 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 planning vector control program in this malarious area.

Tick Ectoparasites of Animals in Borderline of Iran-Iraq and Their Role on Disease Transmission.

BACKGROUND: Since ticks are potent vectors of various diseases, identification of these species are clinically important to protect the public health and control veterinary problems in the communities. We aimed to figure out the frequency of ticks on cows, goats, sheep, lambs, turtles and also obscure hosts in Kurdistan Province, bordered with Iraq June 2012 to May 2013. METHODS: The hosts were selected randomly and examined individually for tick infestation. In case of infestation, ticks were collected using forceps and then preserved in 70% ethyl alcohol. All collected specimens were preserved in tubes and relative information was recorded and then identified based on morphological characteristics. RESULTS: Totally, 1209 ticks were collected. The prevalence of ticks on cows, sheep, goats, lambs, turtles, poultry and obscure hosts was 11.33%, 55.41%, 6.53%, 5.95%, 0.9%, 8.02% and 11.82% respectively. The mean number of ticks on each animal was 1.6. Number of 5 genera, including Rhipicephalus, Argas, Ornithodoros, Hyalomma and Haemaphysalis and 9 species; including R. sanguineus (60.05%), R. bursa (0.08), Hy. anatolicum (12.33), Hy. asiaticum (1.49), Hy. aegyptium (0.91), Hy. marginatum (0.08), Haemaphysalis parva (4.22), Hyalomma sp. (0.99), Ornithodoros lahorensis (11.83), and Argas persicus (8.02) were identified. CONCLUSION: The most abundant species in this study area was Rh. sanguineus (60.05%). Due to high prevalence of tick specimens and a variety of collected species from sheep (55.41%), the vaccination of sheep and control of tick vectors are recommended.

Bio-ecology of malaria vectors in an endemic area, Southeast of Iran.

OBJECTIVE: To determine some bio-ecological aspects of malaria vectors in Jask County, where is targeted for malaria elimination in the national program. METHODS: Mosquitoes were collected monthly during 2013-2014 using different collection methods. Subsequently, ELISA test was used to detect the human blood index of mosquitoes. The susceptibility status of Anopheles stephensi was evaluated against the diagnostic dosages of seven WHO recommended insecticides. RESULTS: A total of 3650 female and 4736 Anopheles larvae were collected including Anopheles stephensi, Anopheles culicifacies s.l., Anopheles dthali, Anopheles fluviatilis s.l., Anopheles moghulensis and Anopheles turkhodi species. Anopheles stephensi was the dominant collected species on human baits and indoors with high rate of unfed and gravid specimens in internal and external window traps. Human blood index was calculated as 14.3% for this species. It was also found to be resistant to DDT and Dieldrin. CONCLUSIONS: The collected species had a wide range of habitats, and resting behaviors. With regarding to the presence of most important malaria vectors in Jask, control of the disease may be so complicated; as based on the weather condition it can be transmitted during the whole year, expect for cold months. With this strong potential of transmission, existing population movements in the area may lead to imported cases of malaria and local outbreak(s). So, more specific studies on malaria vectors in high risk areas of Jask County are recommended.

Ecology of Anopheles stephensi in a malarious area, southeast of Iran.

District of Jiroft is situated in south-east of Iran which is one of the malarious regions. Anopheles stephensi is considered as one of the main malaria vector in this region. Ecology of this species was studied in the area to understand its vector behavior for implementation of effective vector control measures. Different methods like total catch, pit shelter, night bite collection on human and animal, larval dipping methods were used for species identification, seasonal activity, anthropophilic index and egg morphological characteristics. Anthropophilicity index was assessed by ELISA test. Activity of Anopheles species started at the beginning of April, and its peak occurs in late spring. The larvae were found in the river bed with pools, stagnant streams, slow foothill streams, temporary pools, and slowly moving water with and without vegetation, drainage containers of air conditioner and palm irrigation canals. From different methods of adult collection, it was found that spray sheet collection is the appropriate method. ELISA testing of 144 blood meals of females revealed the anthropophilicity of 11.8% indicating host preference on animal, mainly cow. Ridge length and their number on the egg floats confirmed Anopheles stephensi mysorensis form. This study showed that Anopheles stephensi is the main vector of malaria in the region, although some other species may play a role. Our findings could provide a valuable clue for epidemiology and control of malaria in the southeast of Iran.