Employing Different Traps for Collection of Mosquitoes and Detection of Dengue, Chikungunya and Zika Vector, Aedes albopictus, in Borderline of Iran and Pakistan

Entomological surveillance of invasive Aedes mosquitoes in Mazandaran Province, northern Iran from 2014 to 2020

Mosquitoes are the most important vectors of serious infectious diseases in the world. Dengue, Zika, chikungunya and yellow fever are emerging and re-emerging infectious diseases, associated with the distribution of two key vectors i.e. Aedes aegypti and Aedes albopictus throughout the world including countries neighbouring Iran. Entomological surveillance was planned and performed monthly from May to December during 2014-2020 in selected counties of Mazandaran Province, North of Iran, by ovitrap, larval collection, hand catch and human baited trap. Overall, 4410 Aedes specimens including 2376 larvae (53.9%) and 2034 (46.1%) adults belonging to six species, namely Aedes vexans, Aedes geniculatus, Aedes caspius, Aedes echinus, Aedes pulcritarsis and Aedes flavescence were collected and morphologically identified. Over the seven years of surveillance, Ae. aegypti and Ae. albopictus were not found by any sampling method. Aedes vexans and Ae. geniculatus were the most abundant species, their populations peaked in October and November and was positively correlated with precipitation and relative humidity. Aedes flavescence was a new species record for the province. A flowchart for planning and implementation of invasive mosquito surveillance for provincial health authorities in the country is proposed. These surveillance efforts provide basic and timely information for the health system to act promptly on integrated and intensified surveillance and control programs should Ae. aegypti and Ae. albopictus detected in the province.

Climate Crises and Developing Vector-Borne Diseases: A Narrative Review

Background

Climate change based on temperature, humidity and wind can improve many characteristics of the arthropod carrier life cycle, including survival, arthropod population, pathogen communication, and the spread of infectious agents from vectors. This study aimed to find association between content of disease followed climate change we demonstrate in humans.

Methods

All the articles from 2016 to 2021 associated with global climate change and the effect of vector-borne disease were selected form databases including PubMed and the Global Biodiversity information facility database. All the articles selected for this short review were English.

Results

Due to the high burden of infectious diseases and the growing evidence of the possible effects of climate change on the incidence of these diseases, these climate changes can potentially be involved with the COVID-19 epidemic. We highlighted the evidence of vector-borne diseases and the possible effects of climate change on these communicable diseases.

Conclusion

Climate change, specifically in rising temperature system is one of the world's greatest concerns already affected pathogen-vector and host relation. Lice parasitic, fleas, mites, ticks, and mosquitos are the prime public health importance in the transmission of virus to human hosts.

Entomological Surveillance of the Invasive Aedes Species at Higher-Priority Entry Points in Northern Iran: Exploratory Report on a Field Study

Background

Arboviral diseases such as dengue, Zika, and chikungunya are transmitted by Aedes aegypti and Ae albopictus and are emerging global public health concerns.

Objective

This study aimed to provide up-to-date data on the occurrence of the invasive Aedes species in a given area as this is essential for planning and implementing timely control strategies.

Methods

Entomological surveillance was planned and carried out monthly from May 2018 to December 2019 at higher-priority entry points in Guilan Province, Northern Iran, using ovitraps, larval collection, and human-baited traps. Species richness (R), Simpson (D), evenness (E), and Shannon-Wiener indexes (H̕) were measured to better understand the diversity of the Aedes species. The Spearman correlation coefficient and regression models were used for data analysis.

Results

We collected a total of 3964 mosquito samples including 17.20% (682/3964) belonging to the Aedes species, from 3 genera and 13 species, and morphologically identified them from May 2018 to December 2019. Ae vexans and Ae geniculatus, which showed a peak in activity levels and population in October (226/564, 40.07% and 26/103, 25.2%), were the eudominant species (D=75.7%; D=21.2%) with constant (C=100) and frequent (C=66.7%) distributions, respectively. The population of Ae vexans had a significant positive correlation with precipitation (r=0.521; P=.009) and relative humidity (r=0.510; P=.01), whereas it was inversely associated with temperature (r=−0.432; P=.04). The Shannon-Wiener Index was up to 0.84 and 1.04 in the city of Rasht and in July, respectively. The rarefaction curve showed sufficiency in sampling efforts by reaching the asymptotic line at all spatial and temporal scales, except in Rasht and in October.

Conclusions

Although no specimens of the Ae aegypti and Ae albopictus species were collected, this surveillance provides a better understanding of the native Aedes species in the northern regions of Iran. These data will assist the health system in future arbovirus research, and in the implementation of effective vector control and prevention strategies, should Ae aegypti and Ae albopictus be found in the province.

Access, utilization, and barriers to using malaria protection tools in migrants to Iran

Background

Imported malaria cases could be considered one of the threats to malaria elimination. Therefore, increasing migrants’ access to malaria preventive measures can play an essential role in maintaining appropriate conditions and preventing malaria outbreaks. This study aimed to provide detailed information about access, utilization, and barriers to using malaria protection tools in migrants to Iran.

Methods

This study was conducted in a vast region consisting of 4 provinces and 38 cities located in the south and southeast of the country. Study participants were migrants who moved to the study area in the past three months. A sample of 4163 migrants participated in the study. They were selected through a multi-stage sampling method to obtain a representative community sample. Data were collected through interviewer-administered questionnaires about participants’ socio-demographic specification, commuting characteristics, travel aim, access, ways of preparing, and reasons to use or not to use malaria protection tools. Quantitative and qualitative variables were described and analyzed finally.

Results

The mean age of individuals was 28.6 ± 10.8, with a range of 3–88 years old. Migrants’ country of origin was Afghanistan (56.6%), Pakistan (38.4%), and Iran (5%). Most migrants (69.2%) did not have malaria protection tools while staying in Iran. Among those who procured the protection tools, 74% used long-lasting insecticidal nets (LLINs), 13.4% used mosquito repellent sticks and coil, and 12.7% did not use any tools. Respectively, lack of knowledge about where they can get LLINs, followed by being expensive, unavailability in the market, not cooperation of health officer, and no need to use were expressed as the causes for having no access. The main reasons for non-using the tools were lack of knowledge about their application, followed by a defect in protection tools, ineffectiveness, and being harmful, respectively. Migrants who were supported by an employer accessed more to LLINs.

Conclusions

This study reveals significant shortcomings in knowledge, access, and utilization of malaria protection tools among migrants in Iran. Inequitable access to public health services is predictable during migration; however, access to sustainable protection tools is recommended.

Dengue Fever: The Threat of Emerging Diseases Coinciding the Corona Crisis in Southeastern Iran

Collapse

Impact of meteorological parameters on mosquito population abundance and distribution in a former malaria endemic area, central Iran

Meteorological parameters, have been identified as an important factor involved in the transmission of vector-borne diseases. Mosquitoes are extremely sensitive to weather conditions. The aim of this study was investigate the correlation between meteorological parameters and the abundance of mosquitoes in Kashan County. Mosquitoes were collected using four different traps, including hand catch, animal baited bed net trap (usually a cow), human baited bed net trap and BG-Sentinel trap with CO2 from May to December 2019. A total number of mosquitoes collected were 1756 out of which 1621 (92.31%) were Culex, 22 (1.25%) Culiseta and 113 (6.44%) Anopheles in nine species. Most mosquitoes were collected by BG-Sentinel trap with CO2 (63.78%). Monthly distribution of the mosquitoes indicated different monthly peaks. Their high density were recorded in September and were low in December. The spearman's correlation of the mosquito abundance and the meteorological parameters shows that correlation of the number of total collected mosquitoes with relative humidity and precipitation (Rainfall) was weak negative, and there was week correlation with wind speed, and positive strong correlation with temperature. Data collected with various trap types and mosquito correlation with meteorological parameters in this study can be used for mosquito surveillance and control programs. However, meteorological parameters affect the abundance of mosquitoes, but their impact is complex and most of these variables are species specific.