Head lice infestation caused by Pediculus humanus capitis (De Geer) is the most prevalent human ectoparasitic disease worldwide. Head lice are haematophagous, wingless insects belonging to the order Anoplura. Head lice infestation is particularly frequent among children 3–11 years of age, and may induce skin irritation, superinfection from scratching, social stigmatization, and psychological distress [ 1 x 1 Chosidow, O. Scabies and pediculosis. Lancet. 2000; 355: 819–826 Abstract | Full Text | Full Text PDF | PubMed | Scopus (295) | Google Scholar See all References 1 ]. The economic implications are also substantial. An increased rate of louse infestation in recent years has been reported from North and South America, Australia, and a few countries in Europe and Asia [ 2 x 2 Downs, AM, Stafford, KA, Harvey, I, and Coles, GC. Evidence for double resistance to permethrin and malathion in head lice. Br J Dermatol. 1999; 141: 508–511 Crossref | PubMed | Scopus (110) | Google Scholar See all References , 3 x 3 Meinking, TL, Entzel, P, Villar, ME, Vicaria, M, Lemard, GA, and Porcelain, SL. Comparative efficacy of treatments for Pediculosis capitis infestations: update 2000. Arch Dermatol. 2001; 137: 287–292 PubMed | Google Scholar See all References , 4 x 4 Burgess, IF. Human lice and their control. Annu Rev Entomol. 2004; 49: 457–481 Crossref | PubMed | Scopus (117) | Google Scholar See all References ]. Unlike body lice, which are vectors for typhus, recurrent fever, and trench fever, head lice are not known to transmit human infectious pathogens. However, DNA of Bartonella quintana, a bacterium that causes trench fever in humans, has been detected in head lice [ 5 x 5 Sasaki, T, Poudel, SK, Isawa, H et al. First molecular evidence of Bartonella quintana in Pediculus humanus capitis (Phthiraptera: Pediculidae), collected from Nepalese children. J Med Entomol. 2006; 43: 110–112 Crossref | PubMed | Google Scholar See all References , 6 x 6 Bonilla, DL, Kabeya, H, Henn, J, Kramer, VL, and Kosoy, MY. Bartonella quintana in body lice and head lice from homeless persons, San Francisco, California, USA. Emerg Infect Dis. 2009; 15: 912–915 Crossref | PubMed | Scopus (79) | Google Scholar See all References , 7 x 7 Angelakis, E, Diatta, G, Abdissa, A et al. Altitude‐dependent Bartonella quintana genotype C in head lice, Ethiopia. Emerg Infect Dis. 2011; 17: 2357–2359 Crossref | PubMed | Scopus (49) | Google Scholar See all References ].

The development of alternative approaches in ectoparasite management is currently required. Essential oils have been demonstrated to exhibit fumigant and topical toxicity to a number of arthropods. The aim of the present study was to assess the potential efficacy of ten essential oils against Sarcoptes scabiei. The major chemical components of the oils were identified by GC-MS analysis. Contact and fumigation bioassays were performed on Sarcoptes mites collected from experimentally infected pigs. For contact bioassays, essential oils were diluted with paraffin to get concentrations at 10, 5, and even 1% for the most efficient ones. The mites were inspected under a stereomicroscope 10, 20, 30, 40, 50, 60, 90, 120, 150, and 180min after contact. For fumigation bioassay, a filter paper was treated with 100 μL of the pure essential oil. The mites were inspected under a stereomicroscope for the first 5min, and then every 5min until 1h. Using contact bioassays, 1% clove and palmarosa oil killed all the mites within 20 and 50min, respectively. The oils efficacy order was: clove > palmarosa > geranium > tea tree > lavender > manuka > bitter orange > eucalyptus > Japanese cedar. In fumigation bioassays, the efficacy order was: tea tree > clove > eucalyptus > lavender > palmarosa > geranium > Japanese cedar > bitter orange > manuka. In both bioassays, cade oil showed no activity. Essential oils, especially tea tree, clove, palmarosa, and eucalyptus oils, are potential complementary or alternative products to treat S. scabiei infections in humans or animals, as well as to control the mites in the environment.

The bed bugs (Cimex lectularius and C. hemipterus) have undergone a significant resurgence worldwide since the 1990s. A compilation of findings from a database, including 2650 scientific publications from seven major medical databases, allowed us to document main evolutionary events, from fossil evidence, dating from 11,000 years ago, until the present that has led to the current worldwide expansion of Cimicid species. We present the hypotheses on the possible dispersion pathways of bed bugs in light of the major historical and evolutionary events. A detailed classification of the Cimicidae family and finally, an illustrative map displaying the current distribution of known Cimex species in each geographical ecozone of Asia, Europe, Africa, the Americas, and Australia are presented.

Scabies is an ectoparasitic infection caused in humans by the mite Sarcoptes scabiei var. hominis [ 1 x 1 Chosidow, O et al. Scabies and pediculosis. Lancet. 2000; 355: 819–826 Abstract | Full Text | Full Text PDF | PubMed | Scopus (295) | Google Scholar See all References , 2 x 2 Chosidow, O et al. Scabies. N Engl J Med. 2006; 354: 1718–1727 Crossref | PubMed | Scopus (229) | Google Scholar See all References , 3 x 3 Mounsey, KE, McCarthy, JS, Walton, SF et al. Scratching the itch: new tools to advance understanding of scabies. Trends Parasitol. 2013; 29: 35–42 Abstract | Full Text | Full Text PDF | PubMed | Scopus (38) | Google Scholar See all References ]. Scabies remains a significant public health problem worldwide and is the most common skin disease seen in developing countries [ 4 x 4 Hay, RJ, Steer, AC, Engelman, D, Walton, S et al. Scabies in the developing world: its prevalence, complications, and management. Clin Microbiol Infect. 2012; 18: 313–323 Abstract | Full Text | Full Text PDF | PubMed | Scopus (87) | Google Scholar See all References 4 ]. The worldwide prevalence is not known but has been estimated to be 100–300 million cases. The classic manifestation of scabies is generalized itching resulting in sleep loss. Complications, usually due to secondary bacterial infections caused by group A streptococci and Staphylococcus aureus, occur more frequently in developing countries where scabies has been associated with impetigo, post-streptococcal glomerulonephritis and acute rheumatic fever [ 4 x 4 Hay, RJ, Steer, AC, Engelman, D, Walton, S et al. Scabies in the developing world: its prevalence, complications, and management. Clin Microbiol Infect. 2012; 18: 313–323 Abstract | Full Text | Full Text PDF | PubMed | Scopus (87) | Google Scholar See all References 4 ].

The head louse, Pediculus humanus capitis (De Geer), is an hematophagous ectoparasite that affects mainly children. Resistance to insecticides belonging to pyrethroids and other pediculicides, such as malathion, is responsible for frequently reported treatment failures. Recent studies showed that a M815I-T929I-L932F kdr-like mutation in the voltage-gated sodium channel alpha-subunit gene was associated with permethrin resistance in head lice from several countries worldwide. We searched for the presence ofpyrethroid resistance gene in head lice populations obtained in schoolchildren in an urban area of France. All the 15 primary schools of Bobigny, a city located 3 km north of Paris, were selected to participate. Of 3,493 children enrolled, 3,345 (95.8%) children were screened for head lice by using fine-toothed antilouse combs. Live head lice were detected in 112 (3.3%) of children screened. A subsample of 90 lice was processed for DNA study. The amplification of a 332-bp portion of the kdr-like gene spanning the codon 929 was performed, and polymerase chain reaction products were submitted to the restriction enzyme SspI. Twenty of these lice (22.2%) were homozygous susceptible, 33 (36.7%) were homozygous resistant, and 37 (41.1%) were heterozygotes. Globally, the frequency of the T929I mutation was 0.57. The prevalence of pediculosis in schoolchildren of Bobigny seemed relatively low in comparison with findings of other European studies. The presence of the T929I mutation associated with permethrin resistance probably reflected the frequent local use of this insecticide. Further studies are now required to evaluate the prevalence of the kdr-like mutant allele in head lice in French schools.