This research was a descriptive and analytic study, done in 2018 year (Apr to Jun) in student dormitories (males and females) infested with bedbugs in Iran. This study was accepted in ethic committee in medical of Iran by coding. IR. GMU. REC. 2019. 0016.

On 22 Apr 2018, following a report on the infestation of student dormitories to the bedbug, a thorough examination of the rooms was carried out by the medical entomologist of one center for disease control of Iran for one week on the probable spastic spawning places. Examined places included bed metal, Mattress, under the carpet of the room, behind the refrigerator of the room, behind the closets, behind the radiators and suitcases of the students’ clothes. All species were Cimex hemipterus. Two bedbugs male and female were reared in laboratory to study their life cycle [Table/Fig-1].

[Table/Fig-1]:

Cimex hemipterus pronotum with anterior margin moderate (Original photo).

After conducting library studies and consulting with experts in epidemiology and entomology (Reliability), a questionnaire was designed to manage the control of bedbug in the dormitory (MCBBD-Q). For validation of the questionnaire, Cronbach’s alpha was used with a coefficient of 0.7. To determine the consistency of the questionnaire, a test-retest method was used. The questionnaire was completed for 100 students and returned to them after 14 days. The questionnaire was designed in two sections: 1) Demographic information of students; and 2) Questions. Questions were designed in three topics: a) Behavioural Bedbug (X1); b) Individual Management of Bedbug Control (X2, X3); and c) Cumulative Management of Bedbug Control (X4-X10) [Table/Fig-2].

Bedbugs captured from dormitory rooms were transferred to the laboratory’s medical entomology laboratory with laboratory tubes and the genus and species were detected by using the Pratt and Stojanovich identification key [16].

Hundred rooms in two dormitories were surveyed for catching the bedbug and it was found that 25 rooms were infested.

In order to determine the proper method for controlling the bedbug, one room as control and 8 rooms in 3 levels (The rooms were leveled according to the severity infested to bedbug, including high (5> bedbugs) and medium (4-3 bedbugs), and low levels (1-2 bedbugs) were selected randomly as items). In the first eight rooms were used only Insecticide (I),

In the second eight rooms were used Insecticides with a changing mattress (II), and finally, in the remaining 8 rooms, first, the equipments inside the rooms were moved to out of the rooms then, was used of method IPM (III: Insecticides and physically control).

The eight rooms were sprayed by applying a backpack sprayers Hudson in the morning. The insecticide ICON^® mixed with cypermethrin was used at one turn, and one month later, cypermethrin was used mixed with Fouman’s insecticide.

The mattresses of most rooms were zipped, and without a cover, which was a good place to lay the bed bucket. These mattresses were replaced with padding mattresses. To remove eggs and nymphs on mats, mattress covers were opened and boiled in water.

The student’s clothes were washed with 1% permethrin shampoo in the large plastic tub individually. Then the clothes spread out in the sun, and after drying it was ironed.

The beds were removed from the rooms and disinfected in the dorm area with flamethrower, so that the eggs and nymphs in the seamed beds disappeared. To prevent the re-laying of the insect, the seams of the beds were filled with silicone glue. The floors, the back of the radiators, and the walls of the rooms were also heated [Table/Fig-3].

[Table/Fig-3]:

Using of homemade flamethrower for eradication of egg, nymph and adult bedbugs (Original photo).

To check the contamination of the suitcases, the bedside cushion was heated with a hair dryer in the luggage of the clothes, and, if left, the bucket was repaired with a vacuum cleaner.

In order to prevent the possible exit of the bagbed linen from the luggage, the naphthalene was placed inside a plastic bag and placed in the luggage. After this stage, luggage was placed in a garbage bag, and kept away from the student’s bed. It was also recommended that the clothes, bed linen and pillows be sprayed with repellent Dermin (permethrin 5%).

It was recommended to use yellow light for at least five months during sleep at night for the prevention of bedbug bites that are likely to survive.

After completing the mentioned control procedures, it was recommended that the rooms be vacuumed daily for one month.

Another useful initiative was to use glass wool under the mattress pad, which was used in the three level rooms.

After entering the data into the software SPSS ver-20, the correlation coefficient was calculated using one-way ANOVA (analysis of variance), the mean count of bedbugs was compared. Total Insecticides levels and total bedbugs were converted to the logarithmic mode and the amount of insecticide dust was converted to square root before using the ANOVA. Using the Tukey’s HSD test (p=0.05), the mean values were divided. Before removing the bedbugs, the median retreatment counts were compared using the Kruskal-Wallis test, and before removing the infestation, the median visit counts were compared.

Hundred students participated in the completion of the questionnaire, 52 were male and 48 were females. A total of 79 were in age group 18-23 year and 21 were in 24-30 year. More than 80% of the students had no information about bedbug biology, that there were no significant difference between age groups (p-value=0.28) and sex (p-value=0.62). More than 80% students of age 18-23 years and more than 70% of age 24-30 years didn’t check their suitcase. There was a significant difference between age groups 18-30 years (p-value=0.02) and no significant in genders (p-value=0.5). Less than 60% of students in different ages (18-30 years) had cleaned their room for two weeks, no significant difference were found between age groups (p-value=0.60) and genders (p-value=0.72). In others student’s answers weren’t significant difference between age groups and genders (p-value <0.05) [Table/Fig-4]. The percentage of medical students were more followed by nursing, health and paramedicine who participated and completed the questionnaire. Around 56% among them were undergraduates. Approximately, 50% of these students belonged to middle socio-economic groups (monthly income is $ 200-400) as compared to 31% low socio-economic (monthly income is $<200) as 19% high socio-economic group (monthly income is $>400), respectively.

Eighty live bedbugs were captured from 25 infested rooms by using sticky traps, vacuum cleaner, and forceps. Sixty and 20 bedbugs were captured from the male and female students’ dormitories, respectively. The rooms were leveled according to the infested severity, High: 7 rooms had 5> bedbugs, Middle: 10 rooms had 3-4 bedbugs, and Low: 8 rooms had 1-2 bedbugs. Twenty students had a red itchy bump of bedbug bites on their arms.

According to [Table/Fig-5], a significant difference was found by comparing the used methods, in the number of bedbugs after seven days (F=2.60; df=4, 20; p=0.06), 14 days (F=6.27; df=2, 22; p-value=0.07) and 24 days (F=7.65, df=1, 23; p-value=0.01) [Table/Fig-6]. In comparing twin control methods, there were a significant difference in group A (applying Insecticides only in rooms, comparing with Insecticides and changing mattress) (p-value=0.02) and C (IPM with Insecticides and changing mattress) (p-value=0.04) [Table/Fig-7]. There was also a significant difference in the effectiveness of the used control methods (p<0.05), [Table/Fig-8]. The eradication rate of the bedbugs through the three methods (I-III) was 25, 75 and 100%, 24 days after using control methods, respectively. On average, the most effective control method to reduce the number of bedbugs was observed in level 3 rooms (98.9%), whereas the less effective control method was observed in level 1 room (36.25%) [Table/Fig-9].

[Table/Fig-8]:

Comparison between the effectiveness of three methods of bedbug control according eradication time.

[Table/Fig-9]:

Comparison of the efficacy of three methods treatment on reducing the bedbug population in rooms after 24 days.

Y-axis: frequency rooms; X-axis: frequency bedbug

One of the challenges and worries in student dormitories is the release of a bedbug in the student’s rest room, which bites the insect causing the persecution and allergies of these people. Usually, due to the lack of knowledge of students about how to transfer the bedbug from outside to the rooms and the disorderly arrangement of their room equipment, this insect can be easily reproduced. In this study, field studies were carried out following the expansion of the bedbug in students’ rooms and reported bedbug bites, were used of new and old methods that were published in previous studies [13-15].

The results of this study showed that student information about the life cycle of bedbug are low, which requires a training course on familiarisation with bedbug, planned annually by entomologists. Also, checking the suitcases before entering the rooms and vacuuming rooms more than twice a week will prevent the spreading of this insect. Approximately, 50% of these students belonged to middle socio-economic groups (monthly income is $ 200-400, due to the high budgets of controlling the bedbug in human places, do not give much attention to this problem and as a result, the bedbug was entered to the dormitory through student’s suitcase. The use of IPM method along with the use of insecticides reduces the amount of pesticide use and minimises the environmental risks. Another benefit of the IPM method is to prevent the insect’s resistance to pesticides.

Accordingly, bedbug control should be particularly considered, especially in student dormitories, where bedbug bite can lead to distress, difficulty in sleeping, and anaemia among the students [6]. Use of only Insecticides to control bedbugs cannot be effective, since they oviposit in places, where the residual insecticides cannot affect them. In addition, their resistance to the insecticides can result in unnecessary Insecticides and the loss of financial resources, as well. Therefore, physical control methods along with Insecticides (IPM) with phosphorus and pyrethroids insecticide are more effective to control bedbugs in living environments and can lead to the reduced use of insecticides [17].

In the mid-1990s, one of the most important methods to control bedbugs was to use chemical insecticides. The initial solution for the bug control was the burnt sulfur fumigation [3], which was known as the fire and brimstone method. Producing sulfur dioxide and sulfur trioxide, this method effectively controlled all stages of the bedbug life cycle. However, due to the low rate of penetration, it was necessary for some cases of infestation to apply the substance several times. The efficiency of using hydrogen cyanide (solution of hydrocyanic acid in water) as the fumigation was found to be very effective for controlling the insect. Other bedbug controlling chemicals included naphthalene, benzene, kerosene, gasoline, phenol, rotenone, cresol, Lethane 384, turpentine, and alcohol [1,3].

The effect of fumigation and chemicals was not lasting for a long time and as a result, the infestation with bedbug could happen again.

In the late 1980s, there was a major transformation of using pesticides [3,18]. DDVP [4,5,3], organophosphates fenthion [3,19] and several types of pyrethroid Insecticides including cyphenothrin, cypermethrin, deltamethrin and permethrin were among the widely used chemicals [20-22]. Also, to control bedbug, there existed a liquid mixture containing 0.75% deltamethrin, 0.75% propoxur and 0.3% cypermethrin [23].

In this method, to obtain better results, the level of infestation of the rooms, affected sites, how long pesticides can last in the environment, the level of toxicity for humans, the non-resistance of the bedbugs to the selected insecticide, and the cost should be considered. Spraying by residual insecticides of the walls around the rooms by Lambda-cyhalothrin, Cypermethrin, Permethrin was used by the Pest Control Company regardless of the mentioned factors, which based on the results, had no effect on reducing the number of bedbugs. It can be due to the oviposition in hiding places, where spraying by residual insecticides cannot affect the seeds. Bedbugs oviposited more on the students’ beds and mattresses, so the insecticides and spraying type did not affect the number of bedbugs [24].

According to Hwang SW study, insecticides alone can cause some disadvantages and difficulties [25]. According to the studies by Koganemaru R et al., herbal poisoning is more used to control bedbugs currently, which is not effective on the resistant bedbugs; whereas powdered and fumigant insecticides are more effective [26].

In replace mattress method, given that the cloud mattresses used in the rooms lacked a cover, and most of them were zippered mattresses, the bedbug easily laid in the zipper parts, which inevitably replaced the mattresses with covered mattresses. The previous mattresses were kept in the sun for 48 hours, and then stored in an unused storage room until the young ones disappeared. Kells SA studies also point to the important use of mattress cover as a barrier between human skin and sealed mattresses, and the next advantage is to avoid hiding the bug [24].

The students’ clothes were washed individually in a large tub using permethrin shampoo 1% for 1 hour, and were sun-dried for 48 hour, in order to get rid of the hidden bedbugs, since the bedbugs were found more in the students’ baggage in the dormitory rooms. Dried clothes were ironed to remove the live eggs. They were placed inside the cover to avoid recontamination, and placed inside the baggage which was checked with a hair dryer for bedbugs, next to the Naphthalene balls. The baggage containing clothes was placed inside the cover so that the bedbugs inside the room could not enter. Naphthalene, as an insect repellent prevented the live bedbugs to enter or exit the baggage [24].

The gaps inside the metal beds were one of the major hiding places of the bedbugs, which were controlled using flamethrowers. All beds were heated for 5 minutes outside the rooms. Moreover, the gaps inside the rooms are the appropriate hiding places for the nymphs, were heated following transferring the equipment outside, which was effective in reducing the number of bedbugs.

One of the captured (unfed) engorged bedbugs was raring at entomology laboratory to check its biology without feeding. Ovipositor was done and the nymphs were alive for 20 days without feeding. The adult bedbug was alive for 2 months without feeding. In order to prevent the feeding of the bedbugs, students were recommended to have a light source inside the room for two months to prevent the bug bites.

The visible bedbugs inside the room were captured by vacuum cleaner; however, all bedbugs cannot be captured using a vacuum cleaner alone, because some of them were in the hiding places through the day [24].

Putting glass wool below the board under the mattress was another innovative technique. It captured the surviving bedbugs and made them unable to move, which they could easily be captured using forceps.

In a study, Wang C used the non-chemical control methods along with the treatment with insecticide. The operations included the exposure of infested beds and other items to summer sunlight, washing the mattress by hot water poured into the holes and fissures, dropping the bed from a height on the ground to remove bedbugs, using cold water to immerse items for 50 hours, the application of hot steam, using needle to remove the insects, and filling the holes and fissures of floors and walls [3].

In addition, to eliminate some types of bedbug, it is required to wash the clothes and beds and dry them at the temperatures higher than 120°F to vacuum the carpets. Moreover, the soapy water and brush can be used to make the holes and fissures free from bedbug and its eggs.

The infested mattress can simply be controlled by a mattress bag, which is a commercially available large plastic bag known as “encasement”. The bag allows the mattress to be used for sleeping while preventing any bedbug possibly existing in the mattress from leaving. The encasement should also be used to cover the box spring. As bedbug cannot live in the high temperatures, they could be killed by being exposed for 1 hour to the 113°F temperature. It is recommended to assign this pest-control treatment to the experienced and equipped companies [27].

Thirty-two apartments infested with bedbug were detected in a similar study conducted from May to December 2014 in Irvington. Four treatment apartments groups were used: 1) the non-chemical treatment alone; 2) the chemical control treatment alone; 3) the non-chemical and chemical control treatment; and 4) the chemical control treatment alone. The elimination rate in treatments I to IV was 100, 86, 89, and 88%, respectively, at 28 weeks and the need of the insecticides was 58% less than the chemical only treatment [28]. In our study, the eradication rate of the bedbugs through the three methods (I-III) was 25, 75 and 100%.

Impossibility of entering female students’ dormitories, which was a challenge to bedbug control. Another constraint, the control of the bedbug was synchronised with the final examinations of the students’ course, which lost the best time of controlling the bedbug. To overcome these two main problems, students whose rooms were infected by the bedbugs, were transferred to temporary dormitories and female trained staff were used to control bedbug in female dormitories.

According to the results of this study, it is recommended that, for dormitory students there should be planned training sessions, learning about the bedbug biology and its control methods. Also to prevent the entry of the bedbug into the dormitory, it is necessary to check the student’s suitcase out of rooms, covered the mattress, use of standard bed for students, cleaning the rooms more than twice a week with a vacuum cleaner and it is better to use the IPM (Integrated Pest Management) method to control the bedbug in the dormitory, in time.