scholarly journals Expansion of the Knockdown Resistance Frequency Map for Human Head Lice (Phthiraptera: Pediculidae) in the United States Using Quantitative Sequencing

2016 ◽  
Vol 53 (3) ◽  
pp. 653-659 ◽  
Author(s):  
Kyle J. Gellatly ◽  
Sarah Krim ◽  
Daniel J. Palenchar ◽  
Katie Shepherd ◽  
Kyong Sup Yoon ◽  
...  
Keyword(s):  
United States ◽  
Human Head ◽  
The United States ◽  
Head Lice ◽  
Knockdown Resistance ◽  
Frequency Map

scholarly journals Presence of the knockdown resistance (kdr) mutations in the head lice (Pediculus humanus capitis) collected from primary school children of Thailand

2020 ◽  
Vol 14 (12) ◽  
pp. e0008955
Author(s):  
Narisa Brownell ◽  
Sakone Sunantaraporn ◽  
Kobpat Phadungsaksawasdi ◽  
Nirin Seatamanoch ◽  
Switt Kongdachalert ◽  
...  
Keyword(s):  
Head Louse ◽  
Point Mutations ◽  
Human Head ◽  
Amino Acid Sequences ◽  
Primary School Children ◽  
Head Lice ◽  
Knockdown Resistance ◽  
Pediculosis Capitis ◽  
Α Subunit ◽  
Blood Sucking

Human head lice are blood-sucking insects causing an infestation in humans called pediculosis capitis. The infestation is more prevalent in the school-aged population. Scalp itching, a common presenting symptom, results in scratching and sleep disturbance. The condition can lead to social stigmatization which can lead to loss of self-esteem. Currently, the mainstay of treatment for pediculosis is chemical insecticides such as permethrin. The extended use of permethrin worldwide leads to growing pediculicide resistance. The aim of this study is to demonstrate the presence of the knockdown resistance (kdr) mutation in head lice populations from six different localities of Thailand. A total of 260 head lice samples in this study were collected from 15 provinces in the 6 regions of Thailand. Polymerase chain reaction (PCR) was used to amplify the α subunit of voltage-sensitive sodium channel (VSSC) gene, kdr mutation (C→T substitution). Restriction fragment length polymorphism (RFLP) patterns and sequencing were used to identify the kdr T917I mutation and demonstrated three genotypic forms including homozygous susceptible (SS), heterozygous genotype (RS), and homozygous resistant (RR). Of 260 samples from this study, 156 (60.00%) were SS, 58 (22.31%) were RS, and 46 (17.69%) were RR. The overall frequency of the kdr T917I mutation was 0.31. Genotypes frequencies determination using the exact test of Hardy-Weinberg equilibrium found that northern, central, northeastern, southern, and western region of Thailand differed from expectation. The five aforementioned localities had positive inbreeding coefficient value (Fis > 0) which indicated an excess of homozygotes. The nucleotide and amino acid sequences of RS and RR showed T917I and L920F point mutations. In conclusion, this is the first study detecting permethrin resistance among human head lice from Thailand. PCR-RFLP is an easy technique to demonstrate the kdr mutation in head louse. The data obtained from this study would increase awareness of increasing of the kdr mutation in head louse in Thailand.

Knockdown Resistance-Associated Mutations Dominate Populations of the Common Bed Bug (Hemiptera: Cimicidae) Across the South Central United States

2019 ◽  
Vol 56 (6) ◽  
pp. 1678-1683 ◽  
Author(s):  
Jeffrey G Holleman ◽  
Grant A Robison ◽  
Ian J Bellovich ◽  
Warren Booth
Keyword(s):  
United States ◽  
Insecticide Resistance ◽  
The United States ◽  
Knockdown Resistance ◽  
The South ◽  
Α Subunit ◽  
Old World ◽  
Bed Bug ◽  
South Central ◽  
Central United States

Abstract Despite awareness of the mutations conferring insecticide resistance in the bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), within the United States few studies address the distribution and frequency of these. Within the United States, studies have focused on collections made along the East Coast and Midwest, documenting the occurrence of two mutations (V419L and L925I) within the voltage-gated sodium channel α-subunit gene shown to be associated with knockdown resistance (kdr) to pyrethroids. Here, the distribution and frequency of the V419L and L925I site variants is reported from infestations sampled within Oklahoma and its immediately adjacent states. Additionally, the presence of a mutation previously undocumented in the United States (I935F) is noted. While novel in the United States, this mutation has previously been reported in Australian and Old World populations. No infestations were found to harbor wild-type individuals, and hence susceptible, at each of the three sites. Instead, ~21% were found to possess the resistant mutation at the L925I site (haplotype B), ~77% had mutations at both the V419L and L925I sites (haplotype C), and 2% possessed the mutation at the L936F site (haplotype Ab). The high frequency of haplotype C corresponds to previous studies in the United States, and contrasts dramatically with those of the Old World and Australia. The data presented here provide insight into the contemporary occurrence of kdr-associated insecticide resistance in the South Central United States, a region for which data have previously been absent. These data suggest that New World and Old World/Australian infestations are likely to have originated from different origins.

Pyrethroid Pediculicide Resistance of Head Lice in Canada Evaluated by Serial Invasive Signal Amplification Reaction

2010 ◽  
Vol 14 (3) ◽  
pp. 115-118 ◽  
Author(s):  
Danielle Marcoux ◽  
Kathleen G. Palma ◽  
Nalini Kaul ◽  
Hilliary Hodgdon ◽  
Andrea Van Geest ◽  
...  
Keyword(s):  
Allele Frequency ◽  
Signal Amplification ◽  
Head Louse ◽  
Human Head ◽  
The United States ◽  
Head Lice ◽  
Pediculus Humanus Capitis ◽  
Pediculus Humanus ◽  
S Allele ◽  
Amplification Reaction

Background: Most people in the United States and Canada with pediculosis will be treated with neurotoxic pediculicides containing pyrethrins or pyrethroids. Their widespread use led to significant resistance reported from various countries. Although treatment failures are frequently observed in Canada, the resistance frequency to pyrethroid pediculicide of human head lice (Pediculus humanus capitis) has not been determined. Objective: To determine the knockdown resistance ( kdr) allele frequency in human head louse populations in Canada. Methods: Patients infested with Pediculus humanus capitis, aged 4 to 65 years, residents of Ontario, Quebec, and British Columbia, were participants. Head lice were collected by combing and picking the enrolled subjects' hair. Lice were analyzed by serial invasive signal amplification reaction (SISAR) for genotyping the T917I mutation of lice indicating permethrin resistance. The permethrin-resistant kdr allele (R allele) frequency could then be evaluated in the head lice collected in Canada. Results: Of the head louse populations analyzed, 133 of 137 (97.1%) had a resistant (R) allele frequency, whereas only 4 of 137 (2.9%) had a susceptible (S) allele frequency. Conclusions: The 97.1% resistant (R) allele frequency in head lice from Canada could explain the treatment failures encountered with pyrethrin and pyrethroid pediculicide treatments in Canadian populations infested with Pediculus humanus capitis as the latter will not be eliminated by those pediculicides.

scholarly journals Differential Permethrin Susceptibility of Head Lice Sampled in the United States and Borneo

1999 ◽  
Vol 153 (9) ◽  
pp. 969 ◽  
Author(s):  
Richard J. Pollack ◽  
Anthony Kiszewski ◽  
Philip Armstrong ◽  
Christine Hahn ◽  
Nathan Wolfe ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Head Lice

No-Nit Policies in Schools: Time for Change

2007 ◽  
Vol 23 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Patricia Sciscione ◽  
Cheryl A. Krause-Parello
Keyword(s):  
United States ◽  
Scientific Literature ◽  
Scientific Evidence ◽  
School Setting ◽  
The United States ◽  
Personal Contact ◽  
Head Lice ◽  
School Policies ◽  
Head Lice Infestation

No-nit policies that exist in many schools throughout the United States were established years ago based on fear and misinformation, rather than scientific evidence. Children who are found to have live lice are no more infectious on the day of diagnosis than they had been prior to the discovery. Transmission of head lice requires close personal contact, which is not common in the school setting. To date, no scientific literature exists to support the exclusion of children from school due to head lice infestation. Therefore, there is a need to develop updated school policies using research-based evidence to determine the best method of treating infestations while allowing children to remain in school.

scholarly journals Comparative In Vitro Pediculicidal Efficacy of Treatments in a Resistant Head Lice Population in the United States

2002 ◽  
Vol 138 (2) ◽  
Author(s):  
Terri L. Meinking ◽  
Lidia Serrano ◽  
Bruce Hard ◽  
Pamela Entzel ◽  
Glendene Lemard ◽  
...  
Keyword(s):  
United States ◽  
The United States ◽  
Head Lice
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