Vol 4 No 1 (2010)

Articles

  • XML | PDF | downloads: 390 | views: 464 | pages: 1-16

    Background: Biting habit of mosquitoes plays an important role in the epidemiology of mosquito-borne diseases. Mosquitoes use a set of elaborate sensory modalities to find their preferred hosts by exploiting cues emanating from a nearby host. It has been suggested that the chemical profile of skin can provide further support for anthropophilic mosquito species to find their suitable hosts. This study aimed at revealing the value of skin emanation for a zoo- philic species like Anopheles stephensi as a model.
    Methods: Skin emanations of a man, a cow and a Guinea pig were collected by ethanol soaked cottons. Upwind responses of mosquitoes to 100 and 200 3l of filtered skin materials were non-competitively explored in a dual-choice olfactometer. L-lactic acid and other chemical content of the skin samples were identified by an enzymatic kit and GC-MS, respectively.
    Results: Unexpectedly, only human skin emanation was resulted in the statistically significant activation and attrac- tion responses of An. stephensi in the wind tunnel. L-lactic acid content of this skin sample was 10 and 29 times more than the cow and the Guinea pig, respectively. The possible role of lactic acid and a few other identified com- pounds have been discussed here.
    Conclusion: Anopheles stephensi showed higher and more specific upwind responses to human skin emanation in the olfactometer. Undoubtedly, the thorough explanation of this unexpected finding needs further investigation. But, if new data verify this result, then, it may be necessary to reconsider the role of skin emanation and thence the human blood index and vectorial capacity of this zoophilic mosquito.

  • XML | PDF | downloads: 364 | views: 462 | pages: 17-23


    Background:
    Cutaneous leishmaniasis due to Leishmania major has become a hot topic in Iran. The objective of this study was to determine some ecological aspects of sand flies in the study area.
    Methods: Sand flies were collected biweekly from indoors and outdoors fixed places in the selected villages, using 30 sticky paper traps from the beginning to the end of the active season of 2006 in Kerman Province, south of Iran. The flies were mounted and identified. Some blood fed and gravid female sand flies of rodent burrows and indoors were dissected and examined microscopically for natural promastigote infection of Leishmania parasite during August to September.
    Results: In total, 2439 specimens comprising 8 species (3 Phlebotomus and 5 Sergentomyia) were identified. The most common sand fly was P. papatasi and represented 87.1% of sand flies from indoors and 57.2% from outdoors. The activity of the species extended from April to end October. There are two peaks in the density curve of this species, one in June and the second in August. Natural promastigote infection was found in P. papatasi (12.7%).
    Conclusion: Phlebotomus papatasi is considered as a probable vector among gerbils and to humans with a high percentage of promastigote infection in this new focus of cutaneous leishmaniasis. The Bahraman area which until recently was unknown as an endemic area seems now to represent a focus of zoonotic cutaneous leishmaniasis transmission in Iran.

     

     

  • XML | PDF | downloads: 305 | views: 398 | pages: 24-30

    Background: The aim was to evaluate the relapse risk of vivax malaria in patients who received radical treatment in Hormozgan Province, a malarious area located on southeast of Iran.
    Methods: A total of 95 symptomatic vivax malaria infected patients were enrolled in urban health centers of Bandar- Abbas, Minab, Bandar-Jask and Bashagard districts of Hormozgan Province, southeast of Iran from January 2008 to March 2009 for consideration as a case- series study. DNA was extracted from parasite infected whole blood samples. A polymorphic region of Plasmodium vivax merozoite surface protein 1 (pvMSP1) was selected and a PCR method was employed for all the samples to amplify the specific variable gene fragment. The obtained fragments in primary and secondary samples were sequenced. Both nucleotide and amino acid sequences of the samples were investigated for returned patients.
    Results: 3.2% of the patients experienced a second attack between 83-199 days after the initial episode of infection. Alignment of nucleotide and their deduced amino acid sequences between pair sequences of primary and secondary isolates revealed 8 and 6 dissimilarities respectively for the first case, and 9 and 7 dissimilarities for the second case. Although microscopical examination of recurrent thick blood smear of the third patient confirmed new P. vivax  infection, the venous blood sample was accidentally missed. Sequencing results of primary and returned isolates 1P, 1S, 2P, 2S and 3P in this study showed an identity with BP13, T117, BP13, TC28 and Chesson genotypes respectively.
    Conclusion: The returned (secondary) isolates may account to be for the sake of reinfection.

  • XML | PDF | downloads: 352 | views: 475 | pages: 31-41

    Background: The aim of this study was that the past five years data were collected to analyze the situation of malaria and health facilities in this area for better understanding malaria problem and to find solutions.
    Methods: In this retrospective study data of the last 5 years were obtained from health center of Bandar Abbas, published papers and reports, weather forecasting organization of the city and annual reports of Hormozgan official authorities. An excel databank was created and analysis was conducted using this software.
    Results: According to the national health system, Bandar Abbas also has referral net work system from periphery to the district health center. The maximum and minimum Annual Parasitic Index (API) were observed in 2005 (1.31) and 2008 (0.17), respectively. The prevalence of cases in villages was more than city, except for 2008. More than 97.6% of indigenous malaria cases were caused by Plasmodium vivax, although P. falciparum, P. ovale and mix infection were also reported. Anopheles stephensi, An. dthali and An. fluviatilis are the main malaria vectors in rural area, while only the first species is distributed in the urban area.
    Conclusion: According to results and many variables including API, Bandar Abbas is divided in two strata. From the situation analysis of Bandar Abbas it is postulated that the main activities of this district could be accuracy of data, and malaria vector control.

  • XML | PDF | downloads: 476 | views: 540 | pages: 42-46

    Background: Pediculus capitis (Anoplura: Pediculidae) or head louse is an obligate ectoparasite transmitted mainly through physical contact. This study was conducted to survey the prevalence of head lice infestation rate and some risk factors in Primary School pupils, in Khajeh City East Azerbaijan Province, Iran.
    Methods: We selected 20 primary schools of Khajeh City during 2008 and 2009. Totally 500 pupils including 200 boys and 300 girls from all grade 1-5 were selected by multistage, systematic random sampling in rural areas of Khajeh City and were examined for lice. In addition, a standard questionnaire recorded information about demographic features of each pupil. Results were analyzed by SPSS software.
    Results: The total prevalence of head lice infestation in this study was 4.8%. and the prevalence rate was significantly higher in girls (6.66%) than in boys (2%). Epidemiological factors such as: sex, school grade, family size, parent's education, type of house, hair washing (per week), number of using comb per day, were evaluated and results showed significant difference in head lice infestation and sex, school grade ,family size ,father education ,and type of house (P< 0.05).
    Conclusion: Pediculosis is a public health problem in many parts of the world, and due to the higher prevalence of pediculosis in crowded families, family by lower levels of father's education and socioeconomic status in our study and rural area, it is necessary to give health education for families to prevent of pediculosis in this area.

  • XML | PDF | downloads: 388 | views: 450 | pages: 47-53

    Background: Carbaryl (1-naphthyl-N-methyl carbamate) is a chemical in the carbamate family used chiefly as an insecticide. It is a cholinesterase inhibitor and is toxic to humans and classified as a likely human carcinogen. In the present study, the degradation of the carbaryl pesticide was investigated in the laboratory synthetic samples of tap water, in the effect of sonolysis and photolysis processes.
    Methods: This study was conducted during 2006-7 in Chemistry and Biochemistry of Pesticides Laboratory in Tehran University of Medical Sciences (TUMS) in Iran. The carbaryl (80%) was used for preparing samples. First concentration of all samples were 4 mg/l. Sonochemical examinations in ultrasound reactor was done in two 35, 130 Hz, and 100 w, and three time. Photolysis examinations has done in the effect of 400 w lamp and moderate pressure and 6 time, then the amount of pesticide in the samples has been measured by the High Performance Thin Layer Chromatography (HPTLC) method.
    Results: The highest degradation in photolysis process after 1 hour in the 35 KHz was 35%, and in the 130 KHz was 63%. Degradation of carbaryl at 130 KHz is higher than 35 KHz at the same time. Carbaryl elimination was increased by arise frequency and exposure time. After 8 min in photolysis, 100% omitting has been showed.
    Conclusion: Degradation of carbaryl in high frequency ultrasound wavelength was more than low frequency. Degradation of carbaryl in water, combination of high frequency ultrasound wave length and UV irradiation was considerably more effective than ultrasound or ultraviolet irradiation alone.

  • XML | PDF | downloads: 363 | views: 390 | pages: 54-59

    Background: Linguatula serrata is one of well known members of Pentastomida which infects both human and animals. The aim of this study was to evaluate the prevalence of L. serrata in mesenteric lymph nodes, livers and lungs of camels slaughtered in Tabriz area, Iran.
    Methods: Mesenteric lymph nodes (MLNs), livers and lungs of 140 one-humped camels slaughtered in Tabriz, north-west of Iran were investigated for nymphs of L. serrata from July 2007 to June 2008. The organs were examined macroscopically and then a tissue digestion method was also done for investigation of liver and lung of the camels that had infected MLN. The liver and lung samples were mostly taken from condemned and rejected part of organs.
    Results: The infection rate of L. serrata nymphs in MLNs, livers and lungs was 13.5%, 1.4% and 1.4% respectively. The number of isolated nymph in infected lymph nodes varied from 2 to 18 with a mean of 4.78. Only one nymph was isolated from each infected livers and lungs. The infection rate increased with age (p<0.05). No significant difference in different sex groups and seasons was observed (p>0.05).
    Conclusion: Considering this fact that consumption of undercooked camel liver was not common in the studied area, the zoonotic importance of this infection should be concluded.

     

     

  • XML | PDF | downloads: 338 | views: 423 | pages: 60-65

    Background: Indoor residual spraying (IRS) is functioned as national interventions against malaria in southeastern foci of Iran and deltamethrin WP one of the insecticides have been used since past decade. In this study, the residual activity of the wettable granule (WG) was studied on different surfaces in hut scale trial against Anopheles stephensi  in Iranshahr district, southeastern Iran.
    Methods: Three dosages of 25, 40 and 50 mg a.i./m2 of deltamethrin WG 25% formulation were applied on plaster, cement, mud, and wooden surfaces using Hudson® X-pert compression sprayer having 10 litters capacity.
    Results: The residual effects of deltamethrin WG 25% on different surfaces was assessed based on reduction of mortality An. stepehnsi from 100% to about 70%. At 25, 40 and 50 mg a.i./m2 the WG formulation of deltamethrin had a bioefficacy for about 2, 3 and 4 months respectively.
    Conclusion: There was an expectable fluctuation in mortality of An. stephensi at different sprayed surfaces as well as dosages. The proposed 50 mg/m2 WG is the longest activity for up to 4 months which needs to be applied for two spraying cycles per year at the climatically condition of southwestern Iran.

  • XML | PDF | downloads: 583 | views: 458 | pages: 66-71

    Background: Ticks are the main vectors for transmission of different pathogens to human and animals. This survey was performed to find out distribution of ticks, which infested the domestic ruminants in Yazd Province, central Iran during year 2008-2009.
    Methods: A total number of 30 villages from both mountainous (20%) and plateau (80%) regions of the province were selected randomly. Ticks were colleted from the body of infested animals and transported to the laboratory of Medical Entomology, School of Public Health, Tehran University of Medical Sciences and then were identified to space level using valid identification key.
    Results: A total of 583 hard ticks were collected. The ticks were classified into three genera and 7 species including:  Hyalomma dromedarii (55.92%), Hy. marginatum (13.20%), Hy. anatolicum (9.78%), Hy. detritum (4.98%),  Hy. asiaticum (3.94%), Rhipicephalus sanguineus (11.84%), and Dermacentor marginatus (0.34%). The highest seasonal activities occurred in summer. The prevalence of the Ixodidae ticks was more evident in plateaus area in Yazd Province. Among the hosts including: cow, goat, sheep and camel, the ticks that collected from camel was more prevalent. The ratio of male was more than female ticks. Hyalomma. dromedarii was the predominant tick species and accounted for 55.92% of the ticks.
    Conclusion: Some of the collected ticks may play an important role for transmission of vector borne disease to human; therefore, the results of this study will provide a clue for vectors of tick-borne diseases in the region for local authorities for implementation of disease control.

  • XML | PDF | downloads: 413 | views: 414 | pages: 72-76

    We report a case of human urogenital myiasis in an 86-year-old rural man with a penil ulcer and numerous alive and motile larvae from urethra and glans penis. Entomological studies on adult flies showed the larvae were Lucilia sericata  and Wohlfahrtia magnifica. The clinical presentation and treatment strategies are discussed.

  • XML | PDF | downloads: 349 | views: 428 | pages: 77-80

    We report a case of human nasal myiasis caused by flower fly larva in a 14-year-old rural girl in Central Province of Iran. Entomological studies on larva showed the larva as Eristalis tenax which is a rarely cause of nasal myiasis. This is the first reported case of E. tenax larva causing human nasal myiasis in Iran.