Small Mammals as Reservoir for Zoonotic Agents in Afghanistan.

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.

Five years following first detection of Anopheles stephensi (Diptera: Culicidae) in Djibouti, Horn of Africa: populations established-malaria emerging.

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.

Long-lasting permethrin-impregnated clothing: protective efficacy against malaria in hyperendemic foci, and laundering, wearing, and weathering effects on residual bioactivity after worst-case use in the rain forests of French Guiana.

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.

Bioactivity and laundering resistance of five commercially available, factory-treated permethrin-impregnated fabrics for the prevention of mosquito-borne diseases: the need for a standardized testing and licensing procedure.

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.

Pilot study assessing the effectiveness of factory-treated, long-lasting permethrin-impregnated clothing for the prevention of tick bites during occupational tick exposure in highly infested military training areas, Germany.

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.

Human tick infestation pattern, tick-bite rate, and associated Borrelia burgdorferi s.l. infection risk during occupational tick exposure at the Seedorf military training area, northwestern Germany.

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.

First record of the Asian malaria vector Anopheles stephensi and its possible role in the resurgence of malaria in Djibouti, Horn of Africa.

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.

Sentinel site-enhanced near-real time surveillance documenting West Nile virus circulation in two Culex mosquito species indicating different transmission characteristics, Djibouti City, Djibouti.

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.

Synergistic insecticidal and repellent effects of combined pyrethroid and repellent-impregnated bed nets using a novel long-lasting polymer-coating multi-layer technique.

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.

Insecticidal, acaricidal and repellent effects of DEET- and IR3535-impregnated bed nets using a novel long-lasting polymer-coating technique.

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.

Haematophageous vector monitoring in Djibouti city from 2008 to 2009: first records of Culex pipiens ssp. torridus (IGLISCH), and Anopheles sergentii (theobald).

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.

Use of vector diagnostics during military deployments: recent experience in Iraq and Afghanistan.

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.

Tick infestation risk and Borrelia burgdorferi s.l. infection-induced increase in host-finding efficacy of female Ixodes ricinus under natural conditions.

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.

Epidemiology of Plasmodium falciparum and P. vivax malaria endemic in northern Afghanistan.

In 2002, the total malaria burden in Afghanistan was estimated to be 3 million cases annually, mainly from Takhar and Kunduz Provinces. Field investigations from 2001 to 2007 revealed a rapid resurgence of Plasmodium falciparum & P. vivax malaria, with annual incidence rates between 0.0026 & 4.39, and between 0.88 & 13.37 episodes/1,000 person years, respectively. Both diseases peaked during 2002, and then declined independently, indicating two differing modes of transmission and epidemiology. Although control campaigns against malaria tropica, transmitted by the freshwater breeder Anopheles superpictus, were successful, malaria tertiana remained endemic and associated with rice-growing areas, transmitted by the anthropophilic, endophilic or exophilic rice-field breeder, A. pulcherrimus and A. hyrcanus. P. vivax polymorph VK 247 prevailed in 90% of infected mosquito pools. Data documented anthropogenically induced increases in rice-field malaria tertiana in the rice-growing areas of northern Afghanistan and the need for further control strategies, including large-scale larval mosquito eradication in rice-growing areas.

Malaria reemergence in northern Afghanistan.

Field investigations were conducted in Kundoz Province, an Afghan high-risk area, to determine factors responsible for the rapid reemergence of malaria in that country, where 3 million cases were estimated to have occurred during 2002. Results indicate the presence of nonrice-field-dependent Plasmodium falciparum and rice-field-associated P. vivax malaria.

Factory-based permethrin impregnation of uniforms: residual activity against Aedes aegypti and Ixodes ricinus in battle dress uniforms worn under field conditions, and cross-contamination during the laundering and storage process.

The factory-based permethrin coating technique has only recently been developed. Consequently, no data are available on residual activity, laundering, and weathering resistance in impregnated battle dress uniforms (BDUs) worn under military deployment conditions, or on the cross-contamination potential of such uniforms. Herein, factory-impregnated BDUs worn-out during military deployment to Afghanistan were investigated for residual permethrin concentration, residual efficacy against arthropod vectors, and cross-contamination during laundering and storage. When compared with BDUs subjected to 50 defined washings using the U.S. Insect/Arthropod Repellent Fabric Treatment method, no significant differences in efficacy were observed against Aedes mosquitoes, but remaining knockdown activity in Ixodes ticks was significantly better in polymer-coated BDUs. BDUs impregnated by the polymer-coating method were found to be effective for the life of the uniform, ensuring protection of soldiers in the field from arthropod vectors, while causing less cross-contamination than those treated by the Insect/Arthropod Repellent Fabric Treatment method.

Genotoxic effects of pentachlorophenol, lindane, transfluthrin, cyfluthrin, and natural pyrethrum on human mucosal cells of the inferior and middle nasal conchae.

BACKGROUND: Animal experiments and epidemiological studies suggest that pentachlorophenol (PCP) and gamma-hexachlorocyclohexane (lindane) should be classified as possible human carcinogens. In the past, both have had a variety of applications in the civilian and military sectors and in forestry. They have, e.g., been used to impregnate and treat uniforms and other fabrics and to control human lice. Animal experiments indicate that PCP in particular causes mutations and chromosome aberrations and thus DNA damage. Studies on whether or not this also applies to newer substances and especially to natural type I and type II pyrethroids still are not available. What is particularly lacking are data on the genotoxic effects of these substances on human target cells. Our study describes the genotoxic effects of PCP, lindane, transfluthrin, cyfluthrin, and natural pyrethrum on human mucosal cells of the inferior and middle nasal conchae. METHODS: Epithelial cells were isolated from nasal mucosa, which was removed in the surgical treatment of chronic sinusitis and nasal concha hyperplasia. After the cells had been tested for vitality using the trypan blue exclusion test, the short-term culture method was used. The material was incubated with PCP (0.3, 0.75, and 1.2 mmol), lindane (0.5, 0.75, and 1.0 mmol), transfluthrin (0.05, 0.1, 0.5, 0.75, and 1.0 mmol), cyfluthrin (0.05, 0.1, 0.5, 0.75, and 1.0 mmol), natural pyrethrum (0.001, 0.005, 0.01, 0.05, and 0.1 mmol), and N-methyl-N'-nitro-N-nitrosoguanidine for 60 minutes. Substance-induced DNA damage (single-strand and double-strand breaks) were determined using single-cell microgel electrophoresis. A fluorescence microscope was used together with an image processing system to analyze the results obtained. RESULTS: After exposure to all tested substances, a high percentage of the cells of the middle nasal concha in particular were found to have severely fragmented DNA as a result of strong genotoxic effects. Although the reaction of the cells of the inferior nasal concha was significantly less strong (p < 0.001), the tested substances were nevertheless found to have a notable genotoxic effect on these cells too. CONCLUSION: Our study strongly suggests that exposure to PCP, lindane, transfluthrin, cyfluthrin, and natural pyrethrum has a genotoxic effect on the epithelial cells of human nasal mucosa. In addition, we have shown that nasal structures differ in susceptibility to the various pesticides used in the tests. Thus, the study provides new evidence supporting the biological plausibility of PCP- and lindane-induced effects, thereby helping evaluate potential PCP- and lindane-induced mucous membrane carcinomas of these parts of the nose. In addition, our study shows that other substances that today are widely used for controlling pests have a considerable genotoxic effect on human target cells. The results obtained indicate the need for additional studies on the genotoxicity of these substances and their adverse effects on human health.

Contact toxicity and residual activity of different permethrin-based fabric impregnation methods for Aedes aegypti (Diptera: Culicidae), Ixodes ricinus (Acari: Ixodidae), and Lepisma saccharina (Thysanura: Lepismatidae).

The effectiveness and residual activities of permethrin-impregnated military battle dress uniforms were evaluated by comparing a new company-manufactured ready-to-use polymer-coating method with two "dipping methods" that are currently used to treat uniforms. Residual permethrin amounts and remaining contact toxicities on treated fabrics before and after up to 100 launderings were tested against Aedes aegypti (L.), Ixodes ricinus (L.), and Lepisma saccharina (L.). The residual amount of permethrin was considerably higher with the polymer-coating method: 280 mg a.i./m2 after 100 launderings, compared with 16 and 11 mg a.i./m2, respectively, obtained when using the two dipping methods. Hard ticks were most susceptible to the new polymer-coating method, resulting in prelaundering 100% knockdown times of 7.0 +/- 0.9 min, whereas equivalent times for the dipping methods were 7.9 +/- 0.35 min and 8.0 +/- 0.54 min, respectively. After 100 launderings, 100% knockdown of I. ricinus nymphs was reached at 15.2 +/- 1.04 min using the polymer-coating method, compared with 178.8 +/- 24.7 min and 231 +/- 53.6 min, respectively, using the dipping methods. Similar results were obtained for Ae. aegypti and L. saccharina, indicating that the polymer-coating method is more effective and efficient when compared with the dipping methods.