Journal of Arthropod-Borne Diseases
Volume:17 Issue: 2, Jun 2023

Considering the importance of scorpions and recognizing the mechanisms of toxicity caused by their medically important species in Iran and adopting the best therapeutic approach based on these mechanisms, this study was performed by reviewing the clinical manifestations of scorpion stings.

The research was conducted by searching for articles and researches in related websites (PubMed, EMBASE, Scopus, Web of Science and CINAHL) and using domestic and international authoritative journals using the keywords of scorpion, clinical manifestations, in a review method. Finally, 104 qualified sources were selected and after review ing and criticizing these studies, the author's point of view was presented.

Clinical manifestations of Scorpion sting toxicity vary due to the existence of two toxic classes of neurotoxins and cytotoxins or hemotoxins in these arthropods in Iran. The number and distribution of species with neurotoxic ven om are higher than the scorpions with cytotoxic venom and are reported throughout Iran. Scorpions with cytotoxic ven om are mostly widespread in south and southwest of Iran.

Treatment and prevention of scorpion stings in Iran and neighboring countries in the Middle East should be planned based on the mechanism of toxicity and the presence of toxic classes with neurotoxic or cytotoxic venoms.

Reduction of the Aedes aegypti population is the priority effort to control dengue virus transmission in cluding the use of larvivorous fish. Biologically, the predatory efficiency of fish will slow down when the water acidity and temperature change from normal conditions. This study aimed to determine the predatory efficiency of three species of larvivorous fish against the Ae. aegypti larvae in different water temperatures.

Three well-known species of larvivorous fish namely Poecilia reticulata, Betta splendens, and Aplocheilus panchax were placed into 12 cm diameter jars with three water temperature ranges namely 20–21 ºC, 27–28 ºC, and 34–35 ºC, and allowed to three days acclimatization. As many as one hundred 4th-instars larvae of Ae. aegypti were gradual ly entered into each jar, and a longitudinal observation was made at 5, 10, 30, 60, 120, 240, 360, 480, 600, and 720 minutes. The predated larvae were recorded.

In normal temperature ranges, the predatory efficiency of the larvivorous fish was 75%, 72.3%, and 32.8% for B. splendens. Aplocheilus panchax, and P. reticulata, respectively. The predation abilities decreased due to temperature changes. Betta splendens and A. panchax indicated the best predatory efficiency against Ae. aegypti larvae in different temperature conditions.

Betta splendens is the best larvivorous fish in the lower to normal, but A. panchax is the best in the normal to higher temperature ranges. This finding should be considered by public health workers in selecting larvivorous fish to control the Dengue vectors.

Asymptomatic malaria is a major challenge to be addressed in the implementation of the malaria elimina tion program. The main goal of the malaria surveillance system in the elimination phase is to identify reliably all the positive cases of malaria reliably (symptomatic and asymptomatic) in the shortest possible time. This study focused on the monitoring of asymptomatic malaria reservoirs in areas where local transmission had been previously established.

It was a case-study approach that was conducted in the Anarestan area. A total of 246 residents and immi grants living in the area at the age range of 4–60 years old were randomly selected to be tested for malaria by micro scope, RDT, and nested-PCR techniques. The inclusion criterion for participants to be entered into the study was the absence of specific symptoms of malaria. Moreover, participants who have been taking antimalarials for the last month were excluded from the study.

The results indicated no positive cases of asymptomatic malaria among the participants tested by all methods.

The results of this study have shown that, without concerns for asymptomatic parasitic patients, a malaria elimination program has been successfully implemented within the studies area. In addition, the findings emphasized the existence of a strong malaria surveillance system in this area.

Mosquito Control Programs are articulated to control Mosquito Borne Diseases and success of such programs depends on the activities of field workers, and their adherence to the standard operating procedures (SOP’s) is governed by their knowledge, attitudes, and practices (KAP). Present study was intended to assess the KAP of mosquito control workers of Pakistan to get an exact depiction of prevailing situation.  

A cross-sectional descriptive study was conducted in March-April 2020. Questionnaire containing 30 closed and open-ended questions were administrated to participants. Knowledge and practices were evaluated using a scoring system i.e., by giving 1 point to each correct answer while attitude questions were analyzed individually and expressed in percentage for each response.

Total 639 workers were interviewed, mean age was 29.8 (SD ±7.87) years, majority (65.1%) was in age group of 18–30 years. Mean knowledge score was 6.96±1.28 (range 0–9) with 77.36% correct answers (P= 0.073). Mean prac tices score was 7.00±1.62 (range 2–9) with 77.83% appropriate answers (P< 0.001). Both knowledge and practices scores were higher for permanent employees, practices score increased with increase in job experience. Very weak posi tive correlation (r= 0.127) was observed between knowledge and practice scores.

Appropriate practice correlates with better knowledge and positive attitude towards control activities. Hence, training on protection and protective measures for having a positive attitude among healthcare workers is neces sary against the fight with mosquitoes.

Understanding the microbiota of disease vectors can help for developing new strategies to prevent the transmis sion of vector pathogens. Ixodes ricinus is one of the most notorious tick vectors with increasing importance in Iran and other parts of the world while there is limited data on its microbiota. This study aimed to use metagenomics for identifying the I. ricinus tick’s microbiota of Iran.

A total of 39 adult ticks were collected from Mazandaran (21 females), Gilan (17 females), and Golestan (1 male). Five tick pools prepared from 39 adults of I. ricinus were subjected to metagenomics analysis. The data were analyzed by targeting the V6 region of the 16S rRNA gene by Illumina 4000 Hiseq sequencing.

Among hundreds of intestinal microbiota identified by metagenomics, various pathogenic microorganisms distributed in 30 genera and species including those responsible for tick-borne diseases resided in the genera Coxiella, Rickettsia, and Burkholderia were found.

Our results indicated that metagenomics identifies bacteria genera and species which cannot be easily rec ognized by routine methods. The presence of such pathogenic bacteria indicates the importance of possible zoonotic diseases in this region which could affect public health. These results further substantiate the importance of advanced metagenomics analyses to identify neglected tick-borne pathogens which enable researchers to provide efficient mapping roads for the management of emerging and re-emerging infectious diseases.

Bed bugs (Cimex lectularius) are blood-sucking insects that bite humans usually at night and cause nui sance, psychological and social problems. These insects are considered a health hazard in densely populated places such as prisons. The aim of this study was to evaluate the knowledge, attitude and practice of inmates, soldiers, and prison staff regarding bed bugs in Mazandaran prisons.

This is a descriptive-analytical study in which 450 inmates and 210 staff (105 personnel and 105 soldiers) from prisons of Mazandaran Province were included in the study. Data on knowledge, attitude, and practice of the par ticipants regarding bed bugs were collected using a structured questionnaire. To determine the relative content validity coefficient, the questionnaire was assessed by 10 specialists in terms of difficulty, inappropriateness, and ambiguity of the phrases. The reliability of the questionnaire was measured using Cronbach's Alpha and then the data were analyzed using SPSS software version 20.

The maximum mean scores of knowledges, attitude, and practice between the three target groups were 16.42%, 44.07% and 71.21% respectively. Prison staff had the highest knowledge and practice, and inmates showed the highest attitude regarding bed bugs. There was no significant difference between the knowledge and attitude of inmates, prison staff and soldiers (P> 0.05) but there was a significant difference in their practice (P< 0.05).

Results of this study confirmed that all three groups of people in the prisons need appropriate education regarding all aspects of bed bug including its control.

Malaria is the most important tropical and parasitic disease in the world. Endophagy of many malaria vectors advocates that impeding their entry into houses and preventing their contact with the occupants from infective bites could protect them against malaria.

The study was carried out in Jaisalmer District, India and three villages were selected as test villages and three as control. Cross-sectional malaria prevalence surveys and mosquito collections were conducted in all the study villages. Insecticide-treated nets (ITNs) were tied below the beds for personal protection against the mosquito bite. Door and window curtains along with partition curtains were treated with insecticide for baring the entry of mosquito vectors.

Plasmodium vivax and P. falciparum were reported from the study villages. Higher malaria cases were detect ed in the control villages than the insecticide-treated bed net-distributed villages. The percentages of reduction of mos quito density in the houses of the ITNs distributed villages were significantly higher than the control villages. The insec ticide activity was decreased slowly, and the knockdown time (KD50) values were found to be increased with the dura tion of usage of net. The KD50 of Anopheles subpictus s.l. was found to be more than the An. stephensi. Rooms where the ITNs were found to be significantly lower per man-hour density of mosquitoes.

The use of alternative forms of ITNs shows a potential for preventing malaria and are making a significant contribution to the mosquito control. Effective use of ITNs could be helpful in the malaria elimination in India by 2030.

Larvicidal agents can be produced using microbial resources, which are environmentally friendly, biode gradable, and economical. The study's goal was to evaluate the larvicidal activity of metabolites isolated from Nocardia (N. fluminea, N. soli and N. pseudobrasiliensis) and Streptomyces (S. alboflavus) bacterial species against Anopheles stephensi.  

Four metabolites isolated from Nocardia and Streptomyces strains were exanimated for larvicidal activity. The experiments were performed for 24, 48, and 72 hours.  300, 350, 400, 450, 500, 550, and 600 µl of Actinobacteria metabolites were added to 100 cc of dechlorinated water. Fourth-stage larvae were placed in dechlorinated water as a control. LC50 and LC90 were calculated using toxicity data and analyzed.

All metabolites had a statistically significant influence on mosquito larvae (P< 0.05). At 24, 48, and 72 hours, the LC50 for N2 (N. fluminea) was 417, 386, and 370 ppm, respectively, and the LC90 was 650, 595, and 561 ppm. Moreover, LC50 for N4 (N. soli) was 389, 376, and 347 and LC90 were 591, 565, and 533 and LC50 for N5 (N. pseudo brasiliensis) was 390, 357, and 341 ppm and LC90 were 589, 532 ppm. In addition, LC50 for S921 (S. alboflavus) was 484, 416, and 382 ppm, and LC90 was 701, 612, and 574 ppm.

The four bacterial metabolites tested in our study were found to have a notable effect on the mortality rate of Anopheles stephensi larvae, indicating their potential as natural larvicides. This is an effective technique for control ling Anopheles stephensi that has no detrimental environmental impact.