Insecticide susceptibility status of Anopheles gambiae (s.l.) in and surrounding areas of Lake Tana, northwest Ethiopia.

BACKGROUND: Vector control is the most effective malaria control and prevention measure. Among these, IRS and LLINs are the most important chemical insecticide interventions used in malaria prevention and control strategies in Ethiopia. However, the long-term effectiveness of these strategies is under threat due to the emergency and spread of insecticide resistance in the principal malaria vector. Therefore, this study was carried out, under standardized laboratory conditions to assess the killing effect of some insecticides against An. gambiae s.l. METHODS: Mosquitoes in late instar larvae and pupae stages were collected from different breeding habitats of the study sites using a soup ladle (350 ml capacity). The immature was reared to adults at optimum temperature and humidity in a field insectary using the WHO protocol. Four insecticides representing three chemical classes were used against adult mosquitoes. These were permethrin, deltamethrin, pirimiphos-methyl and bendiocarb. Susceptibility tests were carried out from September to December 2021 using the WHO standard procedures. Mortality rate, variation, interaction effect and knockdown times (KDT50 and KDT95%) were computed using descriptive statistics, multivariate analysis of variance and log-probit regression model using SPSS version 20 software. RESULTS: Totally, 1300 Anopheles gambiae s.l. were tested to determine the susceptibility status to the four insecticides. Among these, 90.7% of them were susceptible to insecticides, whereas the remaining 9.3% of specimens were resistant to the insecticides. The results of the analysis of variance showed that mortality significantly varied between insecticides (F = 26.06, DF = 3, P < .0001), but not between study locations (F = 1.56, DF = 3, P = 0.212). On the other hand, the mean comparison of dead mosquitoes showed some signs of interaction between bendiocarb and locations, but not other insecticides and locations. CONCLUSIONS: This study revealed that the knockdown times and effectiveness of different insecticides varied in different study sites. Therefore, insecticide resistance information is very essential for concerned bodies to make informed and evidence-based decisions on vector control.

Prevalence, intensity and associated risk factors of Schistosoma mansoni infections among schoolchildren around Lake Tana, northwestern Ethiopia.

BACKGROUND: Schistosomiasis is one of the widely distributed neglected tropical diseases. It is a serious public health problem in sub-Saharan Africa. The disease is highly prevalent and widely distributed in Ethiopia due to suitable environmental factors and human activities. The prevalence and infection intensity varied from locality to locality in the country. This study aimed to assess the prevalence and intensity of S. mansoni infection and associated risk factors among schoolchildren around Lake Tana. METHODS: A school-based cross-sectional study was conducted among 710 schoolchildren from February to April 2021 in eight selected primary schools around Lake Tana. A questionnaire was used to collect data on socio-demographic information and potential risk factors of S. mansoni infection. After collecting socio-demographic information, students were requested to bring about 2grams of stool specimens for parasitological examination. The collected stool samples were processed using a single Kato-Katz and Ritchie's concentration techniques. The data were analyzed using SPSS software version 23 and factors with a p-value < 0.05 were considered as statistically significant. RESULTS: The overall prevalence of S. mansoni was 34.9% (95% CI: 31.4-38.7) among schoolchildren in the study area. The eggs per gram (EPG) of stool ranged from 24 to 1659 with arithmetic and geometric mean values of 138.1 EPG and 85.1 EPG, respectively. The majority of S. mansoni infections (61.4%) were classified as low infection intensity. Among the different determinant factors being male (AOR = 1.74; 95%CI = 1.233-2.457; P-value = 0.002), bathing habits (AOR = 1.494; 95%CI = 1.013-2.199; P-value = 0.043) and students attending at Qunzela primary school (AOR = 10.545; 95%CI = 3.264-34.067; P-value = 0.001), Alabo primary school (AOR = 3.386; 95%CI = 1.084-10.572; P-value = 0.036) were significantly associated with S. mansoni infection. CONCLUSION: This study revealed that more than one-third of schoolchildren were infected by S. mansoni in the study area. The majority of the infections were classified as low infection intensity. Being male, bathing habits and schools in which students attended were independent explanatory factors for S. mansoni infection. Therefore, integrated control strategies are needed to improve the health conditions of schoolchildren in the study area.

Prevalence and associated factors of Hepatitis C virus and human immunodeficiency virus infections among voluntary counseling and testing clients attending private health facilities in Bahir Dar city, North West Ethiopia 2014.

OBJECTIVE: Although incredible progress has been made in treatment and prevention of Hepatitis C virus and human immunodeficiency virus infections, the epidemic continues to spread in developing nations. The information on the prevalence and risk factors of Hepatitis C virus and human immunodeficiency virus infections among voluntary counseling and testing clients in Ethiopia is limited. Hence, the study aimed to assess the prevalence and associated factors of Hepatitis C virus and human immunodeficiency virus infections among voluntary counseling and testing clients attending private health facilities in Bahir Dar city. RESULT: A total of 382 study participants with the mean age of 25.43 years (SD = ± 6.87) were enrolled. Overall, 14 (3.7%) and 8 (2.1%) voluntary counseling and testing clients were positive for human immunodeficiency virus and Hepatitis C virus respectively. All Hepatitis C virus antibody positive individuals were males (3.8%). The sero-prevalence of Hepatitis C virus was significantly associated with the age group 41-50 years old (AOR = 65.65; 95% CI 4.57-943). Married study participants were also significantly associated with HIV infection (AOR = 7.92, 95% CI 1.32-47.31).