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1.
Parasitol Res ; 122(5): 1199-1211, 2023 May.
Article in English | MEDLINE | ID: mdl-36944808

ABSTRACT

Small mammals are an important reservoir for causative agents of numerous infectious diseases, including zoonotic and vector-borne diseases. The occurrence of these pathogens represents a regional but permanent threat for humans and animals in general and might especially weaken military personnel and companion animals in abroad missions. In our study, small mammals collected in military camps in Afghanistan (Feyzabad, Mazar-e Sharif, and Kunduz) were investigated for the presence of apicomplexans using histopathology and molecular methods. For this purpose, well-established and newly developed real-time PCR assays were applied. A high prevalence was detected not only in house mice (Mus musculus), but also in shrews (Crocidura cf. suaveolens) and grey dwarf hamsters (Cricetulus migratorius). The molecular characterization based on the 18S rRNA gene revealed a close relationship to a cluster of Hepatozoon sp. detected in voles of the genus Microtus. Hepatozoon canis DNA was detected in one house mouse as well as in two Rhipicephalus ticks from a dog puppy. In addition, around 5% of the house mice were found to be infected with far related adeleorinids showing the highest sequence identity of 91.5% to Klossiella equi, the only published Klossiella sequence at present. For their better phylogenetic characterization, we conducted metagenomics by sequencing of two selected samples. The resulting 18S rRNA gene sequences have a length of about 2400 base pairs including an insertion of about 500 base pairs and are 100% identical to each other. Histopathology together with organ tropism and detection rates verified this sequence as of Klossiella muris. In conclusion, we documented naturally occurring protozoan stages and the additional taxonomic characterization of a well-known commensal in mice by applying a combination of different approaches. The study is of medical, social, and biological importance for ensuring human and animal health in military camps and also stresses the required awareness for the potential risk of zoonoses.


Subject(s)
Eucoccidiida , Military Personnel , Parasites , Humans , Animals , Dogs , Mice , Afghanistan , Phylogeny , Shrews
2.
Mil Med ; 187(1-2): e189-e196, 2022 01 04.
Article in English | MEDLINE | ID: mdl-33462624

ABSTRACT

INTRODUCTION: Rodents and other small mammals can serve as reservoirs for a large number of zoonotic pathogens. A higher risk of infection with rodent-borne pathogens exists for humans with direct contact to rodents and/or their excretions, e.g., soldiers in operation areas. To date, little is known about endemic human pathogenic disease agents that are naturally associated with small mammals in Afghanistan. The aim of this study was to screen abundant rodents and insectivores collected from 2009 to 2012 in four field camps of the German Federal Armed Forces (Bundeswehr) in Northern Afghanistan for the presence of different pathogens. MATERIALS AND METHODS: Isolated nucleic acids from ear pinna were screened by real-time PCR for spotted fever group (SFG) rickettsiae and from liver samples for Francisella spp., Coxiella burnetii, Brucella spp., Yersinia pestis, and poxvirus. Chest cavity lavage (CCL) samples were tested for antibodies against SFG and typhus group (TG) rickettsiae, as well as against flaviviruses using an indirect immunofluorescence assay. RESULTS: Rickettsial DNA was detected in 7/750 (1%) ear pinna samples with one being identified as Rickettsia conorii. Antibodies against SFG rickettsiae were detected in 15.3% (n = 67/439) of the small mammals; positive samples were only from house mice (Mus musculus). Antibodies against TG rickettsiae were found in 8.2% (n = 36/439) of the samples, with 35 from house mice and one from gray dwarf hamster (Cricetulus migratorius). Flavivirus-reactive antibodies were detected in 2.3% (n = 10/439) of the investigated CCL samples; again positive samples were exclusively identified in house mice. All 199 investigated liver-derived DNA preparations were negative in the Francisella spp., C. burnetii, Brucella spp., Y. pestis, and poxvirus-specific PCRs. CONCLUSIONS: Further investigations will have to prove the potential value of rodents in army camps as sentinel animals.


Subject(s)
Rickettsia , Afghanistan , Animals , Humans , Mammals/microbiology , Mice , Rickettsia/genetics , Rodentia
3.
Parasitol Res ; 118(3): 725-732, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30671729

ABSTRACT

The Asian malaria mosquito, Anopheles stephensi, is a well-known and important vector of Plasmodium falciparum and P. vivax. Until 2013, its geographical distribution was confined to central and southern Asia including the Arabian Peninsula. In the Horn of Africa (HoA) Region, An. stephensi was first recorded from Djibouti in 2012, when it was linked geographically and temporally with an unusual outbreak of urban P. falciparum malaria. In 2016, An. stephensi was detected in the neighbouring Somali Region of Ethiopia. In order to determine whether An. stephensi populations have become established in Djibouti and contributed to the unusual rise in local malaria cases there, we carried out continuous vector surveillance from January 2013 to December 2017, investigated seasonal changes in An. stephensi population densities and bionomics, analysed available literature describing malaria in Djibouti since 2013, and investigated whether An. stephensi may have contributed to local malaria transmission by detecting circumsporozoite antigen of P. falciparum and P. vivax in female anophelines. From 2013 to 2016, seasonal activity of An. stephensi in urban Djibouti City primarily occurred during the colder, wetter season between September and May, with either no or rare trap catches from June to August. Unlike past years, this species was detected year-round, including the extremely hot summer months of June to August 2017. This change in seasonal occurrence may indicate that An. stephensi populations are adapting to their new environment in sub-Saharan Africa, facilitating their spread within Djibouti City. Among the 96 female An. stephensi investigated for malaria infectivity, three (3.1%) were positive for P. falciparum circumsporozoite antigen, including one P. falciparum/P. vivax VK 210 double infection. Subsequent to the unusual resurgence of local malaria in 2013, with 1684 confirmed cased reported for that year, malaria case numbers increased continuously, peaking at 14,810 in 2017. Prior to 2016, only P. falciparum malaria cases had been reported, but in 2016, autochthonously acquired P. vivax malaria cases occurred for the first time at a rate of 16.7% among all malaria cases recorded that year. This number increased to 36.7% in 2017. Our data indicate that the dynamics of malaria species in Djibouti is currently changing rapidly, and that An. stephensi can be involved in the transmission of both P. falciparum and P. vivax, simultaneously. Considering the extremely high potential impact of urban malaria on public health, the timely deployment of optimal multinational vector surveillance and control programs against An. stephensi is strongly recommended, not only for the HoA Region, but for the entire African continent.


Subject(s)
Anopheles/parasitology , Malaria/transmission , Mosquito Vectors/parasitology , Plasmodium falciparum/physiology , Plasmodium vivax/physiology , Animals , Disease Outbreaks , Djibouti/epidemiology , Epidemiological Monitoring , Female , Humans , Introduced Species , Malaria/epidemiology , Malaria/parasitology , Malaria, Falciparum/epidemiology , Malaria, Falciparum/parasitology , Malaria, Falciparum/transmission , Malaria, Vivax/epidemiology , Malaria, Vivax/parasitology , Malaria, Vivax/transmission , Population Density , Seasons
5.
Parasitol Res ; 116(2): 677-684, 2017 02.
Article in English | MEDLINE | ID: mdl-27942961

ABSTRACT

Personal protective measures against hematophagous vectors constitute the first line of defense against arthropod-borne diseases. However, guidelines for the standardized testing and licensing of insecticide-treated clothing are still lacking. The aim of this study was to analyze the preventive effect of long-lasting polymer-coated permethrin-impregnated clothing (PTBDU) against malaria after exposure to high-level disease transmission sites as well as the corresponding loss of permethrin and bioactivity during worst-case field use. Between August 2011 and June 2012, 25 personnel wearing PTBDUs and exposed for 9.5 person-months in hyperendemic malaria foci in the rain forest of French Guiana contracted no cases of malaria, whereas 125 persons wearing untreated uniforms only, exposed for 30.5 person-months, contracted 11 cases of malaria, indicating that PTBDU use significantly (p = 0.0139) protected against malaria infection. In the field, PTBDUs were laundered between 1 and 218 times (mean 25.2 ± 44.8). After field use, the mean remaining permethrin concentration in PTBDU fabric was 732.1 ± 321.1 min varying between 130 and 1270 mg/m2 (mean 743.9 ± 304.2 mg/m2) in blouses, and between 95 and 1290 mg/m2 (mean 720.2 ± 336.9 mg/m2) in trousers. Corresponding bioactivity, measured according to internal licensing conditions as KD99 times against Aedes aegypti mosquitoes, varied between 27.5 and 142.5 min (mean 47.7 ± 22.1 min) for blouses, and between 25.0 and 360 min (mean 60.2 ± 66.1 min) for trousers. We strongly recommend the use of long-lasting permethrin-impregnated clothing for the prevention of mosquito-borne diseases, including chikungunya, dengue, and zika fevers, which are currently resurging globally.


Subject(s)
Aedes/drug effects , Dengue/prevention & control , Insecticides/pharmacology , Malaria/prevention & control , Permethrin/pharmacology , Protective Clothing , Zika Virus Infection/prevention & control , Animals , Dengue/virology , French Guiana , Humans , Laundering , Malaria/parasitology , Rainforest , Weather , Zika Virus , Zika Virus Infection/virology
6.
Parasitol Res ; 115(4): 1573-82, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26738734

ABSTRACT

Personal protective measures against hematophagous vectors constitute the first line of defense against arthropod-borne diseases. In this regard, a major advance has been the development of residual insecticides that can be impregnated into clothing. Currently, however, information on specific treatment procedures, initial insecticide concentrations, arthropod toxicity, residual activity, and laundering resistance is either fragmentary or non-existent, and no World Health Organization Pesticides Evaluation Scheme or other guidelines exist for the standardized testing and licensing of insecticide-treated clothing. The aim of this study was to analyze the insecticide content, contact toxicity, laundering resistance, and residual activity of five commercially available and commonly used permethrin-treated fabrics-Insect Shield, ExOfficio, Sol's Monarch T-shirts, battle dress uniforms (BDUs), and Labonal socks-against vector-competent Aedes aegypti, Anopheles stephensi, and Culex pipiens mosquitoes under laboratory conditions. Prior to laundering, permethrin concentrations ranged from 4300 to 870 mg/m(2) whereas, after 100 defined machine launderings, the remaining permethrin content fell to between 1800 and 20 mg/m(2), a percentage permethrin loss of 58.1 to 98.5 %. The highest 99 % knockdown (KD99) efficacy of permethrin was detected in Ae. aegypti, followed by An. stephensi and Cx. pipiens demonstrating that Ae. aegypti is the most sensitive species and Cx. pipiens the least sensitive. After 100 launderings, the remaining biocidal efficacy differed markedly among the five brands, with KD99 times varying from 38.8 ± 2.9 to >360 min for Ae. aegypti, from 44 ± 3.5 to >360 min for An. stephensi, and from 98 ± 10.6 to >360 min for Cx. pipiens. Overall, the ranking of the residual biocidal efficacies within the five brands tested was as follows: BDU ≈ Labonal > Sol's Monarch > ExOfficio > Insect Shield. When applying German Armed Forces licensing conditions, none of the four products available in the civilian market would completely meet all the necessary efficacy and safety requirements fulfilled by BDUs. Therefore, we strongly recommend standardized testing and licensing procedures for insecticide-treated clothing, with defined cutoff values for initial maximum and post-laundering minimum concentrations of permethrin as well as figures for permethrin migration rates, arthropod toxicity, homogeneity on fabrics, residual activity, and laundering resistance.


Subject(s)
Aedes/drug effects , Culex/drug effects , Insect Vectors/drug effects , Insecticides/pharmacokinetics , Mosquito Control/methods , Permethrin/pharmacokinetics , Animals , Clothing/standards , Female , Humans , Insect Bites and Stings/prevention & control , Insecticides/analysis , Laundering , Permethrin/analysis , Reference Standards , Textile Industry
7.
Parasitol Res ; 114(2): 671-8, 2015 Feb.
Article in English | MEDLINE | ID: mdl-25416331

ABSTRACT

The protective effectiveness of factory-based permethrin-impregnated polymer-coated battle dress uniforms (PTBDUs) against tick bites was evaluated at four military training areas in southwestern and central Germany where tick bite incidence is known to be high. Data were analyzed by comparing tick bite incidence using non-permethrin-treated BDUs (NTBDUs) during 2009 versus PTBDUs during 2010 and 2011, the first two years after their formal introduction for in-country use in the German Bundeswehr. During 2009, 262 individual tick bites were reported at the four training sites, resulting in a tick bite incidence of 8.8 % per exposed person when wearing NTBDUs only. In 2010 and 2011, one tick bite case occurred under field conditions each year that PTBDUs were worn, corresponding to a protective effectiveness of 99.6 and 98.6 %. These data imply an annual tick bite incidence of 0.035 and 0.078 % per exposed person, respectively. Between 2010 and 2011, a 0.8 % decline in the protective effectiveness of PTBDUs was observed. Five tick bite incidents occurred while wearing non-impregnated parkas over correctly worn PTBDUs. Ixodes ricinus ticks were collected by standard tick drags from 2009 to 2011, with high mean annual densities ranging from 28.9 to 106.5 ticks per 100 m(2), while single drags revealed tick densities between zero and 381 ticks per 100 m(2). Overall, 4596 I. ricinus ticks (54 ♂, 82 ♀, 1776 nymphs, and 2684 larvae) were collected, of which 128 (2.8 %; mean annual range, 0-10.1 %) were Borrelia burgdorferi s.l. positive. The Borrelia genospecies distribution was as follows: 112 (87.5 %) Borrelia afzelii, 10 (7.8 %) B. burgdorferi s.s., and 6 (4.7 %) Borrelia garinii. Neither the tick density means from 2009 to 2011 nor associated B. burgdorferi s.l. prevalences differed significantly among the military locations investigated. The documented tick bite reductions clearly demonstrate the powerful protective effectiveness of properly worn PTBDUs against tick bites. Nevertheless, all apparel worn over PTBDUs should also be impregnated with permethrin in order to prevent tick infestation and subsequent bites.


Subject(s)
Borrelia/isolation & purification , Insecticides/pharmacology , Occupational Exposure , Permethrin/pharmacology , Tick Infestations/prevention & control , Ticks/drug effects , Animals , Clothing , Female , Germany/epidemiology , Humans , Incidence , Ixodes/drug effects , Ixodes/microbiology , Larva , Male , Military Personnel , Nymph , Pilot Projects , Tick Bites/epidemiology , Tick Bites/prevention & control , Tick Infestations/epidemiology , Ticks/microbiology
8.
Ticks Tick Borne Dis ; 5(5): 594-9, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24993582

ABSTRACT

The human tick infestation pattern, tick bite rate, and associated Borrelia burgdorferi s.l.-infection risk were investigated during occupational tick exposure of military personnel at the Seedorf military training area, northwestern Germany, from January to December 2009. Borrelia burgdorferi s.l. seroconversion rates were monitored from April to September 2009. Continuous occupational health surveillance and education were established. Feeding ticks were mostly removed by medical personnel, transferred to 70% ethanol, identified, and tested for B. burgdorferi s.l. Pre- and post-exposure sera were screened for B. burgdorferi s.l. antibodies. A total of 710 feeding ticks was removed, 704 (99.2%) of which were I. ricinus, 5 were I. hexagonus (0.7%), and one was H. concinna (0.1%). Of the I. ricinus specimens, 63.9% were nymphs, 24.7% larvae, 10.9% adult females, and 0.5% adult males. The tick bite rate among occupationally exposed personnel was 42.2% from April to September 2009. Up to 18 simultaneously feeding ticks per person per exposure incident were detected. The mean number of attached ticks was 2.0±2.2 per person per exposure incident. Overall, 86.4% of all feeding ticks were removed from patients within less than 24h after attachment. Borrelia burgdorferi s.l. DNA could be detected in 3.5% of larval, 4.4% of nymphal, 13% of adult female, and 33.3% of adult male ticks, indicating a mean prevalence of 5.3%. Among the genospecies detected, B. afzelii accounted for 84%, B. burgdorferi s.s. for 11%, B. garinii for 3%, and B. spielmanii for 3%. The overall seroconversion rate in 566 personnel exposed from April to September was 1.7%, and 0.7% acquired clinical Lyme borreliosis. Experiences reported herein indicate the need to further improve personal protection measures, health education, and medical staff training in order to minimize exposure to ticks and optimize diagnosis of tick-borne diseases.


Subject(s)
Borrelia burgdorferi Group/isolation & purification , Lyme Disease/microbiology , Tick Bites/epidemiology , Tick Infestations/epidemiology , Animals , Female , Germany/epidemiology , Humans , Larva/classification , Lyme Disease/epidemiology , Male , Military Personnel , Nymph , Occupational Exposure , Seasons
9.
Acta Trop ; 139: 39-43, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25004439

ABSTRACT

Anopheles stephensi is an important vector of urban malaria in India and the Persian Gulf area. Its previously known geographical range includes southern Asia and the Arab Peninsula. For the first time, we report A. stephensi from the African continent, based on collections made in Djibouti, on the Horn of Africa, where this species' occurrence was linked to an unusual urban outbreak of Plasmodium falciparum malaria, with 1228 cases reported from February to May 2013, and a second, more severe epidemic that emerged in November 2013 and resulted in 2017 reported malaria cases between January and February 2014. Anopheles stephensi was initially identified using morphological identification keys, followed by sequencing of the Barcode cytochrome c-oxidase I (COI) gene and the rDNA second internal transcribed spacer (ITS2). Positive tests for P. falciparum circumsporozoite antigen in two of six female A. stephensi trapped in homes of malaria patients in March 2013 are evidence that autochthonous urban malaria transmission by A. stephensi has occurred. Concurrent with the second malaria outbreak, P. falciparum-positive A. stephensi females were detected in Djibouti City starting in November 2013. In sub-Saharan Africa, newly present A. stephensi may pose a significant future health threat because of this species' high susceptibility to P. falciparum infection and its tolerance of urban habitats. This may lead to increased malaria outbreaks in African cities. Rapid interruption of the urban malaria transmission cycle, based on integrated vector surveillance and control programs aimed at the complete eradication of A. stephensi from the African continent, is strongly recommended.


Subject(s)
Anopheles/classification , Malaria/epidemiology , Animals , Anopheles/parasitology , DNA, Ribosomal/genetics , Disease Outbreaks , Djibouti , Female , Humans , Insect Vectors/classification , Insect Vectors/parasitology , Male
11.
J Egypt Soc Parasitol ; 42(2): 461-74, 2012 Aug.
Article in English | MEDLINE | ID: mdl-23214223

ABSTRACT

The Horn of Africa represents a region formerly known to be highly susceptible to mosquito-borne infectious diseases. In order to investigate whether autochthonous WNV transmission occurs in the Djibouti City area, in how far, and which of, the endemic Culex mosquito species are involved in WNV circulation activity,and whether sentinel site-enhanced near-real time surveillance (SSE-NRTS) may increase WNV detection sensitivity, mosquito vector monitoring was conducted from January 2010 to June 2012. Six monitoring locations, including two identified sentinel sites, considered most probable for potential anthroponotic and zoonotic virus circulation activity, have been continuously employed. Among the 20431 mosquitoes collected, 19069 (93.4%) were Cx. quinquefasciatus, and 1345 (6.6%) Cx. pipiens ssp. torridus. WNV lineage 2 circulation activity was detected between December 20th, 2010 and January 7th, 2011. Overall, 19 WNV RNA-positive mosquito pools were detected. Generally, urban environment-specific WNV-RNA circulation took place in Cx. pipiens ssp. torridus, whereas periurban and rural area-linked circulation was detected only in Cx. quinquefasciatus. Serological investigation data from 10 volunteers employed at the dislocated zoonotic WNV transmission sentinel site suggest that six persons (60%) had an acute, or recent, WNV infection. Results show that WNV should be considered endemic for Djibouti and sentinel site-enhanced near-real time surveillance is an elegant and highly effective epidemiological tool. In Djibouti, the endemicity level, public health impact and transmission modes of vector-borne diseases in concordance with locally optimized monitoring and control regimen deserve further investigation.


Subject(s)
Culex/virology , Endemic Diseases , Insect Vectors/virology , West Nile Fever/transmission , West Nile virus/isolation & purification , Animals , Djibouti/epidemiology , Female , Humans , Male , RNA, Viral/isolation & purification , Sentinel Surveillance , West Nile Fever/epidemiology , West Nile virus/genetics , Zoonoses/transmission , Zoonoses/virology
12.
Parasitol Res ; 111(2): 755-65, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22526285

ABSTRACT

New and improved strategies for malaria control and prevention are urgently needed. As a contribution to an optimized personal protection strategy, a novel long-lasting insecticide and repellent-treated net (LLIRN) has been designed by binding combinations of permethrin plus N,N-diethyl-m-toluamide (DEET), or insect repellent 3535 (IR3535), and etofenprox plus DEET, onto fibres of bed net fabric employing a new multi-layer polymer-coating technique. Protective repellent efficacy, toxicological effectiveness and residual activity of 12 LLIRN types have been evaluated by laboratory testing against adult Aedes aegypti. The novel multi-layer LLIRN design allowed simultaneous embedding at concentrations up to 5,930 mg/m(2) for DEET, 3,408 mg/m(2) for IR3535, 2,296 mg/m(2) for permethrin and 2,349 mg/m(2) for etofenprox, respectively. IR3535 layers prevented co-binding of additional pyrethroid-containing polymer layers, thus making pyrethroids plus DEET LLIRNs an ideal combination. All LLIRNs revealed synergistic insecticidal effects which, when measured against concentration controls of the isolated compounds, were significant in all LLIRN types designed. DEET in DEET plus permethrin LLIRNs significantly (p < 0.0001) reduced the concentration-dependent permethrin 100 % knockdown (KD) time from 55 to 75 %, the corresponding 100 % kill time (p < 0.0001) from 55 to 64 %. DEET in DEET plus etofenprox LLIRNs reduced the dose-specific 100 % knockdown (KD) time of etofenprox from 42 to 50 % (p = 0.004), the 100 % kill time from 25 to 38 % (p < 0.0001). Permethrin or etofenprox did not influence spatial repellency of DEET or IR3535 on LLIRNs. Vice versa, DEET and IR3535 increased spatial and excitatory repellency and reduced landing and probing frequency on LLIRNs resulting in strongly enhanced biting protection, even at low concentrations. One hundred percent biting and probing protection of stored LLIRNs was preserved for 83 weeks with the 5,930 mg/m(2) DEET and 2,139 mg/m(2) etofenprox LLIRN, for 72 weeks with the 5,002 mg/m(2) DEET and 2,349 mg/m(2) etofenprox LLIRN, for 63 weeks with the 3,590 mg/m(2) DEET and 1,208 mg/m(2) permethrin LLRN, and for 61 weeks with the 4,711 mg/m(2) DEET and 702 mg/m(2) etofenprox LLIRN. Because 100 % bite protection with up to 75 % quicker contact toxicity of pyrethroids were documented, synergistic toxicological and repellent effects of multi-layer polymer-coating LLIRNs may overcome LLIN-triggered selection pressure for development of new kdr- and metabolic pyrethroid resistances while simultaneously increasing protective efficacy also against kdr- and metabolic pyrethroid-resistant mosquitoes substantially due to the repellent-induced effects of LLIRNs thus indicating that this approach is a promising new candidate for future bed net, curtain, and window screen impregnation aiming at optimized prevention from mosquito-borne diseases.


Subject(s)
Culicidae/drug effects , Insect Repellents/pharmacology , Insecticide-Treated Bednets , Insecticides/pharmacology , Pyrethrins/pharmacology , Animals , Behavior, Animal/drug effects , Culicidae/physiology , Insect Repellents/chemistry , Insecticides/chemistry , Materials Testing , Mosquito Control , Pyrethrins/chemistry , Time Factors
13.
Parasitol Res ; 110(6): 2341-50, 2012 Jun.
Article in English | MEDLINE | ID: mdl-22203521

ABSTRACT

A novel long-lasting insecticide-treated net (LLIN) has been designed by embedding the pyrethroids deltamethrin, cyfluthrin, permethrin, or etofenprox, onto the fibres of bed net cotton fabric by transferring a new polymer-coating technique from clothing to netting material. EN ISO 6330, the more stringent European Norm for domestic washing and drying procedures for textile testing, has been newly employed to monitor and validate more precise wash durability and residual bioactivity of LLINs. Wash durability, residual insecticidal activity and mosquito landing/biting protection has been investigated and compared with four commercially available LLINs. The pyrethroid-embedding impregnation technique allows binding of high concentrations exceeding 8,000 mg permethrin/m(2) within one single-polymer layer. Recovery rates of 95.7 ± 5.8%, 92.4 ± 14.0%, 70.2 ± 9.1%, and 64.2 ± 6.3% for cyfluthrin; 32.4 ± 11.4%, 32.4 ± 12%, 35.1 ± 16.2%, and 35.8 ± 15.7% for deltamethrin; 75.3 ± 12.9%, 57.1 ± 15.8%, 48.5 ± 4.0%, and 35.6 ± 4.7% for etofenprox; and 95.7 ± 5.8%, 80.2 ± 8.6%, 39.1 ± 7.9%, and 34.1 ± 8.8% were measured after 1, 5, 10, and 20 launderings. Laundering resistance was highest with cyfluthrin > deltamethrin ≈ etofenprox ≈ permethrin. After one and five launderings, commercial LLINs revealed percentage pyrethroid recovery rates of 26.3 ± 11.8% and 0.9 ± 1.2% for the Care Plus(®) net; 31.8% and 28.9% for the Permanet(®) 2.0; 61.4% and 45.6% for the Net Protect(®); and 80.4% and 68.3% for the Conmanet(®). Recovery rates reveal that the polymer-coating method resulted in extended wash durability. Dose-dependent 100% knockdown rates were most effective with deltamethrin > cyfluthrin > permethrin ≈ etofenprox. LLINs tested at concentrations up to 8,000 mg permethrin/m(2) did not protect from mosquito bites. Results on long-lasting efficacy and bioactivity of the polymer-coating technique show that this new LLIN technique is a highly promising potential candidate for future malaria control strategies. Standardized machine laundering and drying according to EN ISO 6330 is highly recommended to monitor and validate wash durability and residual activity of LLINs.


Subject(s)
Insecticide-Treated Bednets , Insecticides/analysis , Laundering , Pyrethrins/analysis , Aedes/drug effects , Animals , Biological Assay , Female , Survival Analysis
14.
J Dtsch Dermatol Ges ; 9 Suppl 8: 1-51, 2011 Nov.
Article in German | MEDLINE | ID: mdl-22050890

ABSTRACT

The incidence of cutaneous and mucocutaneous Leishmaniasis (CL/MCL) is increasing globally, also in Germany, although the cases are imported and still low in number. The current evidence for the different therapies has many limitations due to lack of sufficient studies on the different Leishmania species with differing virulence. So far there is no international gold standard for the optimal management. The aim of the German joint working group on Leishmaniasis, formed by the societies of Tropical Medicine (DTG), Chemotherapy (PEG) and Dermatology (DDG), was to establish a guideline for the diagnosis and treatment of CL and MCL in Germany, based on evidence (Medline search yielded 400 articles) and, where lacking, on consensus of the experts. As the clinical features do not necessarily reflect the involved Leishmania species and, as different parasite species and even geographically distinct strains of the same species may require different treatments or varying dosages or durations of therapy, the guidelines suggest for Germany to identify the underlying parasite prior to treatment. Because of relevant differences in prognosis and ensuing therapy species should be identified in i) New World CL/MCL (NWCL/ MCL) to distinguish between L. mexicana-complex and subgenus Viannia, ii) in suspected infections with L. mexicana-complex to distinguish from L. amazonensis, and iii) in Old World CL (OWCL) to distinguish between L. infantum and L. major, L. tropica, or L. aethiopica. A state-of-the-art diagnostic algorithm is presented. For recommendations on localized and systemic drug treatment and physical procedures, data from the accessible literature were adjusted according to the involved parasite species and a clinical differentiation into uncomplicated or complex lesions. Systemic therapy was strictly recommended for i) complex lesions (e. g. > 3 infected lesions, infections in functionally or cosmetically critical areas such as face or hands, presence of lymphangitis), ii) lesions refractory to therapy, iii) NWCL by the subgenus Viannia or by L. amazonensis, iv) in MCL and v) in recalcitrant, or disseminating or diffuse cutaneous courses. In e. g. infection with L. major it encompasses miltefosine, fluconazole and ketoconazole, while antimony or allopurinol were here considered second choice. Local therapy was considered appropriate for i) uncomplicated lesions of OWCL, ii) L. mexicana-complex and iii) pregnant women. In e. g. infection with L. major it encompasses perilesional antimony, combined with cryotherapy, paromomycin 15 %/in methylbenzethoniumchlorid 12 % and thermotherapy. The group also stated that there is an urgent need for improving the design and the way of publishing of clinical trials in leishmaniasis.


Subject(s)
Antiparasitic Agents/therapeutic use , Dermatologic Agents/therapeutic use , Dermatology/standards , Leishmaniasis, Mucocutaneous/diagnosis , Leishmaniasis, Mucocutaneous/therapy , Pregnancy Complications, Parasitic/diagnosis , Pregnancy Complications, Parasitic/therapy , Female , Germany , Humans , Pregnancy
15.
Parasitol Res ; 106(4): 957-65, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20162432

ABSTRACT

A novel long-lasting repellent-treated net (LLRTN) has been designed by binding the skin repellents N,N-diethyl-m-toluamide (DEET), or IR3535, onto the fibres of bed net fabric using a new polymer-coating technique. The repellent toxicological effectiveness and residual activity of a factory-based repellent-impregnated fabric has been evaluated by laboratory testing against adult Aedes aegypti mosquitoes and nymphal Ixodes ricinus ticks. By using this repellent-embedding impregnation technique, concentrations exceeding 10 g/m(2) could be achieved with one single polymer layer. Both DEET- and IR3535-impregnated fabrics revealed a dose-dependent insecticidal as well as acaricidal activity. One hundred percent knockdown times of DEET-treated bed nets ranged from 187.5 +/- 31.8 to 27.5 +/- 3.5 min against A. aegypti, and between 214 +/- 47 and 22.6 +/- 5 min against nymphal I. ricinus, linked to a DEET concentration of 1.08 and 10.58 g/m(2), respectively. With IR3535, A. aegypti produced dose-dependent 100% knockdown times varying from 87.5 +/- 10.6 to 57.5 +/- 3.5 min and between 131.4 +/- 6.5 and 33.8 +/- 5 min against nymphal I. ricinus, respectively, linked to concentrations between 1.59 and 10.02 g/m(2). One hundred percent repellency measured by complete landing and biting protection of impregnated fabric by using the arm-in-cage test could be achieved at DEET concentrations exceeding 3.7 to 3.9 g/m(2), and for IR3535 concentrations over 10 g/m(2). One hundred percent landing and biting protection could be preserved with DEET-treated fabrics for 29 weeks at an initial concentration of 4.66 g/m(2), 54 weeks at 8.8 g/m(2), 58 weeks at 9.96 g/m(2) and 61 weeks at 10.48 g/m(2) for DEET, and 23 weeks for IR3535-treated fabric at a concentration of 10.02 g/m(2). Unlike repellent-treated fabric, a brand of a commercially available long-lasting insecticide-treated net tested containing 500 mg permethrin/m(2) did not protect from mosquito bites. First results on bioactivity and long-lasting efficacy show that the new LLRTN technique is highly promising as a potential candidate for future malaria control strategies, especially in areas where pyrethroid resistance occurs.


Subject(s)
DEET/pharmacology , Drug Carriers/chemistry , Insect Repellents/pharmacology , Insecticide-Treated Bednets , Insecticides/pharmacology , Polymers/chemistry , Propionates/pharmacology , Aedes/drug effects , Animals , Delayed-Action Preparations , Female , Humans , Ixodes/drug effects , Survival Analysis , Time Factors
16.
J Egypt Soc Parasitol ; 40(2): 281-94, 2010 Aug.
Article in English | MEDLINE | ID: mdl-21246936

ABSTRACT

The Horn of Africa represents a region formerly known to be highly susceptible to mosquito-borne infectious diseases. In order to monitor and analyze the current presence and threat of vector mosquitoes, continuous and standardized trapping using CDC light traps without an additional CO2-generator has been carried out at six selected monitoring sites located in Djibouti City, from August 2008 until December 2009. An overall of 620 haematophageous Diptera were trapped, 603 (97.3%) were mosquitoes, 10 (1.6%) were sand flies, and 7 (1.1%) were biting midges, respectively. Genus distribution of mosquitoes revealed that 600 (99.5%) were Culex spp., 2 (0.3%) were Anopheles sergentii, and 1 (0.2%) was Aedes aegypti. Culex species were represented by Cx. quinquefasciatus (78.5%), and Cx. pipiens ssp. torridus (21.5%). The later species was first detected focally in early December 2009 showing a strongly increasing population density resulting in a maximum trap rate of 25 mosquitoes per trap night. Sand flies were all Sergentomyia antennata, and biting midges of the genus Culicoides were represented by C. nubeculosus (71.4%) and C. vexans (28.6 %). The findings included the first records for Cx. pipiens ssp. torridus and An. sergentii in Djibouti. However, none of the captured female Culex spp, the known vector for West Nile Virus, showed positive results for viral nucleic acids using WNV RT-real time PCR system. Also, females An. sergentii were Plasmodium falciparum and P. vivax circumsporozoite protein negative.


Subject(s)
Anopheles/physiology , Culex/physiology , Animals , Communicable Diseases/transmission , Egypt , Female , Insect Vectors , Time Factors
17.
Mil Med ; 174(9): 904-20, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19780365

ABSTRACT

Vector-borne diseases such as malaria, dengue, and leishmaniasis are a threat to military forces deployed outside of the United States. The availability of specific information on the vector-borne disease threat (e.g., presence or absence of a specific disease agent, temporal and geographic distribution of competent vectors, and vector infection rates) allows for effective implementation of appropriate measures to protect our deployed military forces. Vector diagnostics can provide critical, real-time information crucial to establishing effective vector prevention/control programs. In this article we provide an overview of current vector diagnostic capabilities, evaluate the use of vector diagnostics in Operation Enduring Freedom and Operation Iraqi Freedom, and discuss the concept of operations under which vector diagnostics are employed.


Subject(s)
Communicable Diseases/diagnosis , Disease Vectors , Military Personnel , Reagent Kits, Diagnostic , Afghan Campaign 2001- , Animals , Communicable Diseases/epidemiology , Disease Reservoirs , Humans , Insect Bites and Stings/epidemiology , Iraq War, 2003-2011 , Population Surveillance , Reverse Transcriptase Polymerase Chain Reaction/methods , United States/epidemiology
18.
Acta Trop ; 110(1): 28-34, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19161965

ABSTRACT

Following an outbreak of more than 200 cases of zoonotic cutaneous leishmaniasis (ZCL) during 2004 and 2005 among International Security Assistance Force (ISAF) troops stationed in the Mazar-e Sharif (MeS) airport area, epidemiological investigations indicated the presence of a local high-density ZCL focus. Based on ZCL's specific transmission modes, density and seasonality, integrated preventive measures were continuously implemented from February 2006 at a German military camp constructed at MeS. Preventive techniques included such synergistic measures as skin repellents and insecticide-impregnated clothing, bednets and curtains, sand fly and rodent monitoring and control, extended habitat sanitation, and health education, all designed to achieve maximum protection against ZCL. Habitat alteration included: (a) erection of a 3.0m high stone wall around the entire camp area; (b) removal of > or =30cm of the upper earth layer throughout the site; (c) soil compaction and stone paving to a depth of > or =30cm plus compaction of the surrounding area to a distance of 100m outside the camp wall; and (d) regular eradication of vegetation. Aggressive implementation of these measures led to a 166-fold and 546-fold reduction in sand fly numbers and complete eradication of the local rodent reservoir, Rhombomys opimus, inside the camp during 2006 and 2007, respectively. ZCL attack rates decreased significantly (p<0.0001), from 17.5% (14 cases/80 persons) for the 2005 German assessment teams to 0.087% (1 case/1150 persons) for the 2006 contingent, and 0% (0 cases) (p<0.0001) for the 2007 contingent, with Quantified Infection Rates (QIRs) of 0.058, 0.0000055, and 0.0, respectively. Using QIR values, the protective factor of the integrated preventive measures was shown to be > or =10,545 times higher in the 2006 and 2007 contingents, compared with the 2005 assessment teams. Results show that the continuously implemented, integrated preventive techniques used in this study gave excellent and long-lasting protection against zoonotic cutaneous leishmaniasis under field conditions.


Subject(s)
Disease Outbreaks , Infection Control/methods , Leishmaniasis, Cutaneous/epidemiology , Leishmaniasis, Cutaneous/prevention & control , Zoonoses/epidemiology , Zoonoses/transmission , Afghanistan/epidemiology , Animals , Education , Gerbillinae , Humans , Insect Control/methods , Insect Repellents/therapeutic use , Protective Clothing , Rodent Control/methods , Rodentia
19.
Exp Appl Acarol ; 44(2): 137-45, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18273686

ABSTRACT

An investigation of the risk of human tick infestation, together with the prevalence of Borrelia burgdorferi s.l. infection, was conducted in a sylvatic habitat in western Germany to provide data needed for future risk-benefit evaluations of acaricides used for clothing impregnation. Additionally, data were collected on behavioural changes in Borrelia burgdorferi s.l.-infected adult female I. ricinus ticks and the possible impact of such changes on host-finding efficacy. The risk of I. ricinus-infestation was determined by collecting from the protective clothing of volunteers and by dragging in known tick-infested sites in the Kühkopf Mountain area, Koblenz, Germany, from June through October 2006. The overall tick infestation rate per person per hour was 7.4+/-5.5, with the following sex- and stage-specific differences: males 0.32+/-0.37, females 1.1+/-1.2, nymphs 3.6+/-4.4, larvae 2.4+/-3.5. Concurrent dragging revealed an average 19.4+/-16.2 times higher infestation rate as well as a markedly lower infection rate with borreliae in adult I. ricinus ticks when compared to ticks collected from exposed human volunteers. Although the difference in infection rates was statistically significant (P<0.023) only in adult female ticks, our data indicate that B. burgdorferi s.l. infection may increase host-finding efficacy in adult I. ricinus. The overall exposure risk was 1.0 B. burgdorferi s.l.-infected ticks per person per hour of exposure, or 0.25 ticks per 100 m walking distance in the study area.


Subject(s)
Borrelia burgdorferi/isolation & purification , Ixodes/microbiology , Ixodes/pathogenicity , Lyme Disease/epidemiology , Tick Infestations/epidemiology , Animals , Borrelia burgdorferi/pathogenicity , Clothing , Female , Germany , Host-Parasite Interactions , Ixodes/physiology , Male , Risk Factors , Seasons
20.
Int J Hyg Environ Health ; 211(1-2): 88-104, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18222725

ABSTRACT

In an age when vector-borne diseases are emerging worldwide, personal protective measures are essential for shielding soldiers and other exposed persons from arthropod attack. The development of permethrin-impregnated clothing has been one recent advance in protecting persons at-risk. However, to date risk assessment has not been performed related to wearing permethrin-impregnated clothing over longer time periods. Therefore, this paper describes relevant toxicological aspects of permethrin and estimates the extent of dermal permethrin uptake by soldiers wearing impregnated uniforms by determining urine metabolites of permethrin. The exposure monitoring conducted in wearers of untreated uniforms did not show any signs of increased permethrin uptake and was similar to that of the general population in Germany. By contrast, studies involving the soldiers wearing permethrin-impregnated uniforms identified far higher internal exposure, the amounts of urine metabolites clearly above the reference value for the background exposure of the German population at large. Comparing the median excretion values, an approximately 200 times higher exposure can be assumed. The excretion levels of the subject with the maximum amount of metabolites correspond to an internal exposure of around 5-6microg/kg body weight and day thereby considering that biomonitoring could not take all urine metabolites and other elimination routes into account. Based on an oral absorption rate of 50%, the internal dose of 5-6microg/kg body weight and day would correspond to an oral uptake of permethrin which is around 20% of the ADI value of 50microg/kg body weight and day. In addition, based on these data and using a dermal absorption rate of 2% the permethrin dose reaching the skin was estimated to be 250microg/kg body weight and day. Considering a standard body weight and the area covered by the uniform, an exposure level of about 1.25microg permethrin/cm(2) skin and day can be calculated. Clinical subjective symptoms were recorded by means of a self-reporting questionnaire which has been developed and used for this specific purpose in environmental outpatient departments in both groups (wearers of impregnated versus non-impregnated uniforms). Only minor sensory impairments were identified in one of the studies (Kabul/Afghanistan) which may represent skin paraesthesiae. Based on these results, it can be assumed that the normal use of permethrin-treated uniforms does not affect human health to a clinical relevant extent. We recommend that the release rate of permethrin from the textile material should be strictly monitored by means of a quality assurance method. It should comply with standards to which the results of this study may contribute.


Subject(s)
Insecticides/adverse effects , Military Personnel , Occupational Exposure/analysis , Permethrin/adverse effects , Protective Clothing , Skin Absorption , Germany , Humans , Insecticides/analysis , Occupational Exposure/adverse effects , Permethrin/analysis , Risk Assessment
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