[The common bed bug (Cimex lectularius) - biology, medical relevance, possibilities for the detection and control]. / Stenice domácí (Cimex lectularius) - biologie, zdravotnický význam, moznosti detekce a hubení.

Bed bugs have become a major concern worldwide in the 21st century and are therefore intensively investigated. The new findings not only extend the knowledge of their biology, medical relevance, and causes of the resurgence, but also can be used in bed bug management. A brief overview is provided of some of the most important research results and opinions, published in the last few years in prestigious international journals.

[West Nile virus transmission risk in the Czech Republic]. / Rizika sírení viru západonilské horecky v Ceské republice.

West Nile Virus (WNV) belongs to the family Flaviviridae. It is transmitted to humans by mosquitoes, capable of sucking blood on birds and mammals, most often by mosquitoes of the genus Culex. In humans, the virus was first identified in 1937 in the West Nile region, Uganda, Africa. Later, the virus spread and caused more or less severe epidemics of West Nile fever in North Africa, Europe, Asia, and North and South America. During the last two decades, WNV has been on the rise and is currently ranked as one of the most prevalent arboviruses in the world. In humans, WNV infection mostly occurs as asymptomatic, but may have a more severe or even fatal course in older and weakened patients. Humans may become infected not only by mosquitoes that acquire the virus from infected birds, but also through a blood transfusion, organ transplant, breast milk and transplacental transmission, or contact with infected animals, their blood, and tissues. The first autochthonous human case of West Nile fever in the Czech Republic was reported from South Moravia in 1997. In 2013, another case of West Nile fever emerged in this country, in the Ostrava area. The issue of WNV has recently been studied from many different perspectives, as evidenced by many original and review papers. This article briefly reviews the essential knowledge about this virus and its spread.

[Prevention of tick-borne meningoencephalitis--summary report]. / Prevence klíst'ové meningoencefalitidy--souhrnné sdelení.

Tick-borne meningoencephalitis is a zoonosis that shows an upward trend. The causative agent is an RNA virus of the family Flaviviridae whose vector in Central Europe is the castor bean tick (Ixodes ricinus). The infection is most often transmitted via tick bite or, less commonly, by the alimentary route, through the consumption of unpasteurized milk of infected animals. Preventive measures consist in personal protection from ticks, exceptionally in blanket treatment with contact insecticides, in preventing consumption of unpasteurized milk and dairy products from areas with a high incidence of tick-borne encephalitis, and particularly in vaccination of the susceptible population.

[In vitro efficacy of three novel delousing formulations against the head louse (Pediculus capitis L.)]. / Ucinnost trí nových odvsivovacích prípravku na ves detskou (Pediculus capitis L.) v in vitro testech--krátké sdelení.

A total of 498 head lice (2nd and 3rd instar larvae, females and males) combed out of the hair of 38 children, were exposed to the delousing formulations Diffusil H Forte Spray (carbaryl 1%), Diffusil Care (isopropyl myristate, cyclomethicone, and dimethiconol) and Paranit (coconut oil, anise oil, and ylang ylang oil) in in vitro tests. The first two formulations, i. e. Diffusil H Forte Spray and Diffusil Care, caused 100% mortality of exposed lice, while Paranit only killed 12.2% of exposed lice.

[Pediatric head lice: taxonomy, incidence, resistance, delousing]. / Ves detská: systematika, výskyt, rezistence, odvsivování.

Based on the current knowledge, head louse (Pediculus capitis) and body louse (Pediculus humanus) are two different species that infest specific parts of the human body and do not interbreed in vivo. In 1991-2002, 6 257 cases of pediculosis were reported in the Czech Republic while 3 138 000 pediculicide packagings, i.e. about 500 times as many as the number of cases, were marketed. Between October 2004 and February 2005, a total of 531 children aged between 6 and 15 years from 16 selected schools in the Zlín and Olomouc regions were screened by dry hair combing. Living lice were detected in 14.1% of the enrolled children and dead nits alone were observed in other 9.8% of the subjects. In vitro tests revealed that the collected head lice were highly resistant to malathion, the active ingredient of Diffusil H 92 M. The number of reported cases of pediculosis roughly doubled in 2005.

A resistance of head lice (Pediculus capitis) to permethrin in Czech Republic.

An outbreak of pediculosis at primary schools was recorded in the Czech Republic in 1992. Almost 20% of children in some schools were infested. This outbreak can be attributed to the resistance of head lice to permethrin, which has not been mentioned in literature yet. The resistance factors established in three towns range between 2 and 385 and between 5 and 557 for LC50 and LC90 values, respectively. This resistance has developed after exclusive use of pyrethroids lotion and shampoo in the Czech Republic since 1978, and it was accompanied by a cross-resistance to d-phenothrin and bioalethrin. But the susceptibility of head lice to malathion and pirimiphos-methyl in 1992 was very similar to that found in 1981. The lotion containing 0.3% of malathion (Diffusil H92 M) has been fully effective against the resistant lice. When introduced into the practice, it quickly reduced the infestation of children in primary schools. The other lotion and shampoo containing 0.3% and 0.7% of pirimiphos-methyl respectively were found to be effective as well.

[Findings of body lice (Pediculus humanus L.) in Czechoslovakia]. / Nález vsi satní (Pediculus humanus L.) v Ceskoslovensku.

The first finding of body lice in Czechoslovakia since year 1945 is demonstrated. The determination of the species is based on the location of the louse on the body of the infested person and on the significant differences in the length of tibia of middle legs in these lice and those collected from the head of children. Local eradication was achieved by using formulation containing permethrin, against head lice.

[Control of Monomorium pharaonis using a methoprene bait in the Berlin Zoo and its combined application with a residue insecticide in the Olomouc Children's Clinic]. / Die Bekämpfung von Monomorium pharaonis mit einem Methoprenköder im Tierpark Berlin) und dessen kombinierte Anwendung mit einem Rückstandsinsektizid in der Kinderklinik Olomouc.

The control of Monomorium pharaonis by a methoprene bait in the Tierpark Berlin and its combined application with a residue insecticide in the children's hospital in Olomouc. In two different institutions heavy infestations with the Pharaoh's ant (Monomorium pharaonis L.) could be eradicated with a methoprene bait applied by different methods. In a zoological garden the bait was continuously exposed in boxes for many weeks. The dosage was about 2.5 g/10 m2, and 1.42 kg of DYBH-bait were used. On average 50% of this amount was taken off by the ants during the eradication period of 14...37 weeks. In a children's hospital after spraying permethrin 10 weeks before the bait was exposed uncovered with 0.5 g per bait station. Within 13 days an area of 9,000 m2 was treated with about 1.8 kg of DYBH-bait. 131/2 weeks after the beginning of the application no more ants could be detected by visual checking. Further checking with baited traps after 128 days confirmed eradication. The bait was very persistent being still attractive and effective after an exposition of about 8 months.

Susceptibility to DDT and some other insecticides of head lice (Pediculus capitis De Geer) in Czechoslovakia.

For testing the susceptibility of the head louse to insecticides impregnated bunches of polyamide fibres, whose diameter resembled that of human hair (0.1 mm) were used. In this manner a low mortality of control lice collected from infected persons was obtained (2.9% after 16 hours of exposure). Even after 25 years of DDT use no apparent resistance could be demonstrated in 25 tested louse populations and cross resistance to permethrin in 7 tested populations. The diagnostic concentration for resistance to pp'-DDT was established at 1%. Of the tested insecticides the highest toxicity was shown by malathion (LC50 = 0.000 018%), pirimiphos-methyl had on average a twice lower toxicity, trichlorphon 104 times lower, tetramethrin 1220 times lower, permethrin 2.5 times lower and pp'-DDT 630 times lower toxicity.

Effectiveness of methoprene-impregnated baits in the control of Monomorium pharaonis ant populations infesting health establishment and households.

The use of baits consisting of dried egg yolks and impregnated with 0.5% of methoprene, loosely applied twice within 8-12 days at the rate of 1 g of bait per 3-6 m2 of floor surface area at each application was found to result consequently in a complete eradication of M. pharaonis ant populations in two medium-size health establishments and in one apartment house. Under more favorable conditions in another health establishment the use of methoprene-impregnated baits applied twice at the average dose of 1 g per as many as 46 m2 floor area proved equally effective in ensuring permanent eradication of ants. Providing that all colonies on the premises can be affected by bait a complete eradication of ants can be expected within 100 days after the first application of bait.

Effectiveness of fenitrothion for area control of ticks Ixodes ricinus (L.).

Susceptibility to fenitrothion in all stages of unfed ticks Ixodes ricinus increases with their age and this fact is reflected in the effectiveness of various dosages of insecticides applied for area control. The following minimum, but fully effective dosages of the dust Metation P-5 and the spray Metation E-50 (both preparations contain fenitrothion) for application in separate seasons have been ascertained: In September and October 1 kg of fenitrothion per ha of treated area ensures complete control of unfed ticks until the winter of current year. In Aril 3 kg of fenitrothion per ha is necessary, if tick control is to be ensured until the appearance of the new generation, i.e. until the end of August. In May the control of unfed ticks is ensured by 1 kg of fenitrothion per ha, in June to August by 0.3 kg per ha is fully efficacious.