Current Situation of Malaria and Resistance of Main Vectors to WHO Recommended Insecticides in an Endemic Area, Southeastern Iran

Although malaria is endemic in some areas of southeastern Iran, following the successful national malaria elimination plan, the local transmission area has been shrunk. The main cases in Iran are due to Plasmodium vivax followed by P. falciparum. This study was aimed to determine the current situation of malaria in Kerman Province of Iran and evaluate the insecticide resistance of main vectors. The field study was conducted in 2019. Data of new malaria cases were obtained from the health centers for the period of 2009–2018. Susceptibility status of Anopheles stephensi and An. dthali was evaluated against dichlorodiphenyltrichloroethane, Dieldrin, Malathion, Bendiocarb, Deltamethrin, and Temephos at the diagnostic dose. A total of 522 malaria cases were recorded and divided into indigenous (33.14%) and imported (66.86%) categories. The highest incidence of the disease was reported from the southern areas of the province, where all indigenous cases occurred. Adults of An. stephensi were resistant to dichlorodiphenyltrichloroethane while its resistance to be confirmed to dieldrin, bendiocarb and deltamethrin. As An. dthali had less than 98% mortality against bendiocarb, the resistance status should be confirmed with more tests. Our findings showed both species had less than 98% mortality against bendiocarb and deltamethrin insecticides which are used in malaria vector control program in Iran. Due to the susceptibility of these vectors to temephos, larviciding can be advised for vector control in this area.

Insecticides Susceptibility Status of Malaria Vectors in a High Malaria Endemic Tribal District Gadchiroli (Maharashtra) of India

Background and Objective: The current study was undertaken to determine insecticide susceptibility of malaria vectors in various villages of high malaria endemic PHCs of Gadchiroli district of Maharashtra. Methods: Adult malaria vectors were collected from the human dwellings/ cattle sheds of 156 villages of 18 malaria endemic PHCs. Susceptibility tests were carried out for different insecticides against An. culicifacies and An. fluviatilis mosquitoes as per the World Health Organization (WHO) procedure. Cone bioassays were also done to assess the quality and efficacy of indoor residual spray. Results:An. fluviatilis could be collected from 23 villages only and all the populations were fully susceptible to synthetic pyrethroid (deltamethrin) while being tolerant to organophosphorous (malathion). Susceptibility of An. culicifacies from 156 villages indicated that only 3 populations of An. culicifacies were resistant to deltamethrin while 57 populations were fully susceptible and other 96 populations were tolerant to deltamethrin. Resistance was recorded in 25 populations of An. culicifacies against malathion and 30 populations were tolerant to malathion insecticide. Remaining populations of An. fluviatilis and An. culicifacies were highly resistant to organochlorine. Results of cone bioassay revealed the mortality ranged from 32.5-51.1% on cemented and 27.5-43.3% on the mud wall sprayed with lambda cyhalothrin. Conclusion: The current study indicates that resistance has developed to synthetic pyrethroids in the major malaria vector An. culicifacies. Therefore, there is an urgent need for the evaluation of new insecticide molecules for better control of malaria vectors.

Preliminary Report of the Insecticide Susceptibility Status of Aedes Albopictus in Bangladesh

Aedes albopictus is a highly invasive mosquito species and a vector of human arboviral diseases including dengue, chikungunya, and Zika. There are no effective drugs or vaccines for the treatment or prevention of most of these diseases, so the primary option for disease prevention and control is to target mosquitoes, often using insecticides. Despite vector control efforts, cases of arboviral diseases are increasing in Bangladesh and it is important to understand if this escalation is associated with the presence of insecticide resistance in Aedes populations, including Ae. albopictus. The CDC bottle bioassays performed on Ae. albopictus from two districts in Bangladesh detected resistance to permethrin but susceptibility to deltamethrin, malathion, and bendiocarb. The detection of permethrin resistance is worrisome, since arbovirus vector control strategies in Bangladesh currently include the use of permethrin. Routine monitoring of the susceptibility status of key vector populations in Bangladesh will allow a better understanding of resistance trends, enabling the strengthening of control strategies.

Chest X-Ray Findings in Drug Sensitive and Drug Resistant Pulmonary Tuberculosis Patients in Uganda

Background: Tuberculosis (TB) is one of the leading causes of death worldwide. Radiology has an important role in the diagnosis of both drug-sensitive (DS) and drug-resistant (DR) pulmonary TB (PTB). This study aimed at comparing the chest x-ray (CXR) patterns of microbiologically confirmed cases of DS and DR PTB in Uganda.Methods: We conducted a hospital based retrospective study at the Mulago National Referral Hospital (MNRH) TB wards. All participants had microbiologically confirmed diagnosis of PTB. CXR findings extracted included infiltrate, consolidation, cavity, fibrosis, bronchiectasis, atelectasis and other non-lung parenchymal findings. All films were independently examined by two experienced radiologists blinded to clinical diagnosis.Results: We analyzed CXR findings of 165 participants: 139 DS- and 26 DR-TB cases. Majority (n=118, 71.7%) of the participants were seronegative for HIV. Overall, 5/165 (3%) participants had normal CXR. There was no statistically significant difference in the proportion of participants with consolidations (74.8% versus 88.5%; p – 0.203), bronchopneumonic opacities (56.1% versus 42.3%, p=0.207) and cavities (38.1% versus 46.2%, p=0.514), across drug susceptibility status (DS versus DR TB). Among HIV infected participants, consolidations were predominantly in the middle lung zone in the DS TB group and in the lower lung zone in the DR TB group (42.5% versus 12.8%, p – 0.66). HIV infected participants with DR TB had statistically significantly larger cavity sizes compared to their HIV uninfected counterparts with DR TB (7.7 ± 6.8cm versus 4.2 ± 1.3cm, p – 0.004). Conclusion- We observed that a vast majority of participants had similar CXR changes, irrespective of drug susceptibility status. However, HIV infected DR PTB had larger cavities. The diagnostic utility of cavity sizes for the differentiation of DR from DS TB could be investigated further.

Identification of pathogens isolated in acute external otitis cases and evaluation of aminoglycoside and quinolone sensitivity

ObjectiveThis study aimed to identify pathogens isolated in acute external otitis cases and determine their distribution according to ages and seasons as well as investigate the susceptibility or resistance to the aminoglycoside and quinolone group antibiotics of which topical forms are available.MethodA total of 168 patients diagnosed with acute external otitis were evaluated retrospectively. Growing bacteria were identified according to the species by conventional methods. Antibiotic susceptibility status was determined for the growing bacteria.ResultsThe most common bacteria detected were pseudomonas group bacteria (38.7 per cent). Resistance to the amikacin group of antibiotics was found to be the lowest and resistance to the ciprofloxacin group of antibiotics was the highest.ConclusionExternal auditory canal cultures should be taken simultaneously with empirical treatment. Seasonal effect and age group should be taken into consideration in the choice of treatment and after questioning about chronic exposure to water. Empirical treatment should then be started.

ENTOMOLOGICAL INDEX AND INSECTICIDE SUSCEPTIBILITY STATUS IN DENGUE-ENDEMIC AREAS YOGYAKARTA

Backgrounds: Dengue Hemorrhagic Fever (DHF) is a disease that receives special attention because of causing outbreaks in some countries, including Indonesia. The problems that often emerge on the DHF Control Program are the high vector density (Aedes aegypti) and the vector resistance resulting from continuous insecticide use. This study describes the entomological index and susceptibility status of Aedes aegypti against malathion and permethrin insecticides in Sorosutan, Umbulharjo, Yogyakarta.Methods: This study used a descriptive observational method with a cross-sectional design. An entomological survey is done at 354 houses in Sorosutan, which is randomly selected. The sample of Aedes aegypti was obtained through the larval collection and ovitrap installation in 100 places. Susceptibility tests performed using the bioassay method with impregnated paper were based on the WHO standard. This study was conducted from December 2018 – February 2019. The data were analyzed using univariate analysisResults: The entomological survey in Sorosutan showed the House Index value was 35.03%; Container Index was 16.68%; Breteau Index was 46.33; Density Figure was 5.00, and Larva Free Rate was 64.97%; meaning that Sorosutan had a high level of vector density. So, the risk of DHF transmission was high. The population of Aedes aegypti in Sorosutan has been tolerant against Malathion, with 87.83% mosquito mortality.Conclusion: Sorosutan was an area with high DHF transmission risk. Aedes aegypti population in Sorosutan has been tolerant against Malathion.

STATUS KERENTANAN NYAMUK Aedes aegypti TERHADAP INSEKTISIDA SIPERMETRIN DI AREA PERIMETER DAN BUFFER PELABUHAN TANJUNG EMAS KOTA SEMARANG

An assessment of the use of insecticides needs to be done because of the threat of insecticide resistance problems in the application of vector control for dengue. A descriptive observational study was conducted to determine the susceptibility status of Ae. aegypti against 0.05% cypermethrin insecticide at Tanjung Emas Port, Semarang. The study was conducted using the WHO standard bioassay, biochemical, and molecular (PCR) assays. Interviews were conducted with selected respondents to find out the history of insecticide use. The results showed that the susceptibility status of the Aedes aegypti mosquito in the perimeter and buffer area with the WHO standard bioassay test was still vulnerable, with the mortality of Aedes aegypti samples collected from the two study sites being 100%. Biochemical tests showed that 0.05% cypermethrin was still susceptible to Ae. aegypti, with a yield of 100% mortality in both study areas. However, the results of the PCR test showed that homozygous resistance and heterozygous resistance were 80% and 20% respectively in the perimeter region, while in the buffer region it was 40% and 60%, respectively. The results of interviews with program managers showed that 100% of the officers had complied with the standard operating procedure for fogging activities with the insecticides used, i.e. malathion and cypermethrin. Both types of insecticides have been used on a rotational basis. However, the rotation of these insecticides has not been carried out routinely and periodically. Abstrak Evaluasi terhadap penggunaan insektisida perlu dilakukan karena adanya ancaman masalah resistensi insektisida dalam aplikasi program pengendalian vektor demam berdarah dengue. Studi observasional deskriptif dilakukan untuk melihat status kerentanan Aedes aegypti terhadap insektisida sipermetrin 0,05% di Pelabuhan Tanjung Emas Semarang. Studi menggunakan uji bioassay standar WHO, biokimia, dan molekuler (PCR). Kegiatan wawancara dilakukan pada responden terpilih untuk mengetahui riwayat penggunaan insektisida. Responden dalam penelitian ini adalah pengelola program dan masyarakat. Hasil penelitian menunjukkan Ae. aegypti di area perimeter dan buffer dengan uji bioassay standar WHO masih rentan, dengan kematian nyamuk uji yang dikoleksi dari dua lokasi studi masing-masing sebesar 100%. Uji biokimia menunjukkan bahwa sipermetrin 0,05% masih susceptible terhadap Ae. aegypti, dengan hasil sebesar 100% kematian di kedua area studi. Namun, uji PCR menunjukkan sudah terdapat proses mekanisme menuju resistensi dengan hasil resisten homozigot dan resisten heterozigot di area perimeter adalah 80% dan 20%, sedangkan area buffer adalah 40% dan 60%. Hasil wawancara dengan pengelola program menunjukkan 100% petugas sudah menerapkan standar, operasi, dan pelaksanaan kegiatan fogging dengan benar menggunakan insektisida bahan aktif malathion dan sipermetrin. Kedua jenis insektisida ini telah digunakan secara rotasi. Namun, rotasi insektisida tersebut belum dilakukan secara rutin dan berkala

Susceptibility of Anopheles Mosquitoes to Deltamethrin and Bendiocarb Insecticides in Nasarawa Local Government Area, Nasarawa State Nigeria

Anopheles mosquito’s resistance to insecticides has been one of the major challenges in eradicating malaria. This study was carried out to determine the susceptibility status of Anopheles mosquitoes to Deltamethrin and Bendiocarb in some communities of Nasarawa Local Government Area of Nasarawa State for four months. The research was carried out at the insectary laboratory of Nasarawa State University Keffi. Center for Disease Control (CDC) bioassay bottle and WHO impregnated papers were used to test the susceptibility of Anopheles mosquitoes. The result shows that Anopheles mosquitoes exposed to Bendiocarb and Deltamethrin using CDC bioassay bottles were susceptible at 15mins, there was no mortality recorded from the control at 30 minutes of exposure. Anopheles mosquitoes exposed to WHO impregnated paper of Bendiocarb and Deltamethrin were susceptible at 60 minutes, mortality was recorded at 24h post exposure time from the control. χ2analysis of Bendiocarb and Deltamethrin insecticides exposed to CDC bioassay bottles was statistically insignificant p>0.05, while χ2 analysis of Bendiocarb and Deltamethrin exposed to WHO impregnated papers was also insignificant p>0.05. These results indicated susceptibility of Anopheles mosquitoes to Bendiocarb and Deltamethrin for the two methods of susceptibility test. The use of these synthetic insecticides in the control of malaria should be encouraged and made available.