Subject(s)
Arachnid Vectors , Infectious Disease Transmission, Vertical , Ornithodoros , Relapsing Fever/congenital , Relapsing Fever/transmission , Animals , Arachnid Vectors/microbiology , Blood Cell Count , Endemic Diseases/statistics & numerical data , Female , Humans , Infant, Newborn , Infectious Disease Transmission, Vertical/statistics & numerical data , Iran/epidemiology , Jaundice, Neonatal/microbiology , Male , Muscle Weakness/microbiology , Neonatal Screening , Ornithodoros/microbiology , Pregnancy , Relapsing Fever/diagnosis , Relapsing Fever/drug therapy , Relapsing Fever/epidemiologyABSTRACT
The present study has been designed in order to verify the species composition within Anopheles maculipennis complex in North West of Iran. We determined ribosomal DNA sequences of the second internal transcribed spacer (ITS2) region from samples of Anopheles maculipennis Complex in Zanjan province. A total of 1536 specimens within the Complex were tested by Multiplex PCR, only An. maculipennis was found in this area. One clone out of four different individual mosquitoes of each field was generated with ITS2 PCR and half of them (192 samples) selected randomly for RFLPs. PCR-RFLP assay identified 2 haplotypes; haplotype I (99%) and haplotype II (1%). Twenty five sequences were generated comprising the 5.8S gene, the ITS2 and the 28S ribosomal gene. The alignment was 422 in length and percentage of GC content was 50.3% (26.07% A, 23.59% T, 26.78% C, 23.7% G). The ITS2 was 290 bp in length and two haplotypes were revealed varying by a single base (T<-->C) at site 378. An. maculipennis is the dominant species anopheline of the province. ITS2 analysis revealed evidence of a slightly interaspecific variation among populations. However, further investigations on the genetic polymorphism among An. maculipennis populations and in particular within those belonging to the continental haplotype are required to support any hypothesis on differences in behavior across the distribution range for this potential malaria vector.
Subject(s)
Anopheles/genetics , DNA, Intergenic/genetics , Sequence Analysis, DNA , Animals , Anopheles/classification , Base Sequence , Haplotypes , Humans , Insect Vectors/genetics , Iran , Molecular Sequence Data , Polymorphism, Genetic , Polymorphism, Restriction Fragment Length , Random Allocation , Sequence AlignmentABSTRACT
In a study carried out in the Ghassreghand Division (Baluchistan, Iran) from March through November 1995, efficacy of cyfluthrin-impregnated bednets was compared to that of untreated nets, in relation to malaria control. Ten villages with a total population of 4,572 and 3 villages with a total population of 1,935 were used as treatment and control, respectively. The collection, impregnation (target dosage of 40 mg active ingredient [AI]/m2), and redistribution of the nets (9% nylon, 52% light cotton, 30% medium cotton, and 9% heavy cotton), carried out in mid-April, were done by local health workers, supervised by the senior research staff. Anopheles culicifacies was considered to be the main vector of malaria in the named area. This species is mainly zoophilic, endophilic, and exophagic. The initial uptake of the insecticide was lower than the target dosage, with high variation (nylon, 12.5 +/- 5.4 mg AI/m2; light cotton, 33.3 +/- 26.1 mg AI/m2; medium cotton, 25.9 +/- 20 mg AI/m2; heavy cotton, 17.6 +/- 12.5 mg AI/m2). The use of impregnated mosquito nets (used primarily outside) had no significant effect on the incidence of malaria. No difference was detected in the parasite density of patients with positive slides. No significant effect was observed in the parous rate, human blood index, and sporozoite rate of anopheline vectors. Only the indoor resting densities of An. culicifacies and other malaria vectors were drastically reduced after the introduction of the cyfluthrin-impregnated nets into the treatment villages. The residual activity of cyfluthrin was lower than expected. The mortality of anophelines brought in contact with the treated nets for 3 min in bioassays dropped to less than 55% in 3 months. The loss of chemical activity was greatest for the light cotton nets, followed by the medium cotton nets. Cyfluthrin-treated nets were mildly irritating to host-seeking female anophelines in the laboratory. The protective rate of impregnation (all fabric kinds included) in preventing female mosquitoes from biting through the impregnated nets was initially 5-6 times that of the nonimpregnated nets. The study did not detect any significant difference between the use of untreated versus impregnated bednets in the Ghassreghand area. In planning future medium-scale trials, comparison of new compounds and formulations to the more widely used pyrethroids such as permethrin and deltamethrin is highly recommended.
