Associations of Plasmodium and Intestinal Helminth Infections with Maternal Anemia and Adverse Pregnancy Outcomes in Northwest Ethiopia.

Malaria and intestinal helminth infections are significant public health challenges in Ethiopia. However, little is known about the relationship of Plasmodium and intestinal helminth infections in pregnancy with maternal anemia and adverse pregnancy outcomes. A health-facility-based cross-sectional study was conducted among 526 parturients in northwest Ethiopia to investigate the associations of these parasitic infections with anemia and adverse pregnancy outcomes. Maternal and newborn profiles were collected using questionnaires and checklists. Maternal hematocrit was determined using the micro-hematocrit method. Malaria was diagnosed by microscopy, rapid diagnostic tests, and quantitative polymerase chain reaction, whereas intestinal parasites were detected microscopically using stool wet mount and Kato-Katz preparations. Among the women, 38.6% were anemic, and 36.5% had adverse pregnancy outcomes. Single infections of hookworm (adjusted odds ratio [aOR] = 3.11, 95% CI: 1.64-5.87) in pregnancy were associated with anemia at parturiency, whereas malaria single infections were associated with anemia (aOR = 4.28, 95% CI: 2.17-8.23) and adverse pregnancy outcomes (aOR = 2.94, 95% CI: 1.47-5.91). Moreover, intestinal helminth coinfections in pregnancy were associated with anemia (aOR = 13.3, 95% CI: 4.8-36.8), whereas malaria-helminth coinfections were associated with anemia (aOR = 7.47, 95% CI: 3.71-15.04) and adverse pregnancies (aOR = 4.75, 95% CI: 2.36-9.57). Overall, the study showed that Plasmodium and intestinal helminth infections in pregnancy are associated with anemia and adverse pregnancy outcomes. Thus, strengthening malaria and intestinal parasite infection prevention and control practices in pregnancy is warranted to alleviate the burden of anemia and adverse pregnancy outcomes.

Evaluating the Performance of FlukeCatcher at Detecting Urogenital Schistosomiasis.

Urine filtration microscopy (UFM) lacks sensitivity in detecting low-intensity Schistosoma haematobium infections. In pursuit of a superior alternative, this study evaluated the performance of FlukeCatcher microscopy (FCM) at detecting S. haematobium eggs in human urine samples. Urine samples were collected from 572 school-age children in Afar, Ethiopia in July 2023 and examined using UFM and FCM approaches. Using the combined UFM and FCM results as a reference, the sensitivity, negative predictive value, and agreement levels for the two testing methods in detecting S. haematobium eggs in urine samples were calculated. The sensitivity and negative predictive value of detecting S. haematobium eggs in urine samples for FCM was 84% and 97%, respectively, compared to 65% and 93% for UFM. The FCM test results had an agreement of 61% with the UFM results, compared to 90% with the combined results of FCM and UFM. However, the average egg count estimates were lower when using FCM (6.6 eggs per 10 mL) compared to UFM (14.7 eggs per 10 mL) (p < 0.0001). Incorporating FCM into specimen processing could improve the diagnosis of S. haematobium infection but may underperform in characterizing the intensity of infection.

Ecology and Infection Status of Sand Flies in Rural and Urban Cutaneous Leishmaniasis Endemic Areas in Northwest Ethiopia.

Cutaneous leishmaniasis (CL) caused by Leishmania aethiopica is transmitted by Phlebotomus longipes in northern Ethiopia. No studies have been conducted to investigate the transmission dynamics of CL, despite its high endemicity in both rural and urban settings. Evidence on the ecology and behavior of the vector from this area are required to develop integrated disease control strategies. Sand flies were collected in the dry and wet seasons in 2021 in CL-endemic rural Gindmeteaye and urban Addis-Alem in northwest Ethiopia. Trapping was performed with sticky and Centers for Disease Control and Prevention (CDC) light traps in three habitats, including inside patients' houses, peridomestic areasand in caves/rocky areas. Sand flies were morphologically identified to species level. Female Phlebotomus species were categorized according to blood feeding status and tested by spliced-leader (SL-) ribonucleic acid (RNA) polymerase chain reaction (PCR) to screen for Leishmania infection. Of 1161 sand flies, the majority (77%) were P. longipes, six (0.5%) were P. orientalis and the remaining were Sergentomyia. The abundance of the 430 female P. longipes was significantly linked to seasonality (p < 0.001), with the majority in the dry season occurring in the outdoor rocky (37%) and peridomestic (34%) sites, while, in the wet season, most (62%) were captured indoors. This seasonality was more pronounced in rural Gindmeteaye, where housing construction is poor. The number of blood-fed and gravid P. longipes was significantly higher in the wet (31%; 22%), compared to the dry season (13%; 8%), and their proportion was highest indoors. Eighteen (4%) female P. longipes were Leishmania positive, with highest infection prevalence in caves (7% compared to 3% indoors, p = 0.022), and in the dry season (6%, p < 0.001). Phlebotomus orientalis specimens were all captured in May in rural Gindmeteaye, five indoors and one in a peridomestic site. Further research should be conducted to investigate the absolute contribution of humans and indoor transmission to the transmission cycle of CL. Inhabitants of endemic villages should be made aware that evening outdoor activities near caves may increase their exposure to infectious sand flies. Whether P. orientalis can breed and become infected at high altitudes should be further studied.

Assessment of Urogenital Schistosomiasis Knowledge, Attitudes and Practices Among Abobo Communities in Gambella Regional State, Southwestern Ethiopia.

Background: Knowledge about community awareness and practices related to a disease, among other things, helps to plan relevant control strategies. This study assessed the knowledge, attitude, and practices (KAPs) of the community in Abobo district of Gambella Regional State in Southwestern Ethiopia about urogenital schistosomiasis (UGS), which is endemic to the region. Methods: A community-based cross-sectional study was conducted in 2022. A pretested structured questionnaire was administered. Multivariable logistic regression was used to examine factors associated with KAPs variables. Results: Most study participants (90.6%) responded they have previously heard of UGS. Over 95% of the participants knew at least 1 symptom of UGS and 30% knew the transmission cycle. About 15.9% and 26.8% knew keeping environmental hygiene and refraining from using cercariae infested water, as preventive methods, respectively. Over half of the participants (50.1%) disagreed or did not know that urinating close to the river/dam water contributes to transmission, and almost all participants had contact with the dam/river water in one way or another. Education status and history of having the infection were the key significant correlates of most KAPs variables. Conclusion: Most of the community members had poor knowledge and attitudes about the mode of transmission and preventive measures of UGS. Thus, besides school-based mass drug administration (MDA), UGS control efforts in the region should incorporate health education in conjunction with safe water supplies, and provision of sanitary facilities to effectively reduce the transmission of the disease.

The potential of addressing asymptomatic malaria in the context of malaria elimination in Ethiopia: Scoping review.

Objectives: Currently, evidence synthesis targeting asymptomatic malaria infections in Ethiopia are scarce. This review intended to collect and organize information on asymptomatic malaria. Methods: A Joanna Briggs Institute, scoping review protocol was used. Searches for peer-reviewed articles published between 01 January 2010 and 10 August 2022, were done through a variety of databases, and gray literatures. Results: 17 articles were included out of 7672 articles identified. There was no any longitudinal study to trace forward these asymptomatic malaria cases. The reviewed studies did not address how asymptomatic malaria could be treated. Moreover, living in index houses, their neighbours and family sizes were the main predictors and more associated with onward transmission of malaria. Asymptomatic malaria (ASM) infection might persist in all seasons except June-August, for which data is lacking. Conclusions: Therefore, as implication of research and policy, it would be necessary to focus on index families and their neighbours in prevention of ASM, conducting longitudinal studies to ascertain when and how many asymptomatic malaria cases without fever during diagnosis would develop clinical malaria. As well, establishing a more sensitive diagnostic technique of malaria surveillance. It is also necessary to provide information regarding the feasibility of treating asymptomatic malaria cases in Ethiopia.

Plasmodium infections and associated risk factors among parturients in Jawi district, northwest Ethiopia: a cross-sectional study.

BACKGROUND: Pregnant women have an increased risk of Plasmodium infections and disease. Malaria in pregnancy is a major public health problem in endemic areas. Assessment of the burden and risk factors of malaria in pregnancy across different malaria transmission settings is required to guide control strategies and for malaria elimination. Thus, the current study is generating such evidence from parturient women in northwest Ethiopia. METHODS: A cross-sectional study was conducted among 526 pregnant women admitted to the delivery rooms of selected health facilities in Jawi district, northwest Ethiopia, between November 2021 and July 2022. Data on the socio-demographic, clinical, obstetric, and malaria prevention practices of pregnant women were collected using interviewer-administered questionnaires and from women's treatment cards. Malaria was diagnosed by light microscopy, rapid diagnostic test, and multiplex real-time polymerase chain reaction. Risk factors for malaria were evaluated using bivariable and multivariable logistic regression models. A P-value of < 0.05 was considered statistically significant. RESULTS: Among the examined parturient women, 14.3% (95% CI 11.4-17.5%) had Plasmodium infections. The prevalence of peripheral, placental, and congenital malaria was 12.2% (95% CI 9.5-15.3%), 10.9% (95% CI 8.2-14.1%), and 3.7% (95% CI 2.3-6.1%), respectively. About 90.6% of peripheral and 92% of placental Plasmodium infections were asymptomatic. Plasmodium infection at parturiency was independently predicted by maternal illiteracy (AOR = 2.03, 95% CI 1.11-3.74), primigravidity (AOR = 1.88, 95% CI 1.01-3.49), lack of antenatal care follow-up (AOR = 2.28, 95% CI 1.04-5.03), and history of symptomatic malaria during pregnancy (AOR = 4.2, 95% CI 2.32-7.59). Moreover, the blood group O phenotype was significantly associated with placental malaria among the primiparae. CONCLUSIONS: Overall, asymptomatic Plasmodium infections were prevalent among parturients in northwest Ethiopia. Maternal illiteracy, primigravidity, lack of antenatal care follow-up, and history of symptomatic malaria during pregnancy were the risk factors for malaria during parturiency. Thus, promotion of a healthy pregnancy through ANC follow-up, strengthening malaria prevention and control practices, and screening of malaria in asymptomatic pregnant women are suggested to reduce its burden in pregnancy.

Cutaneous leishmaniasis in Kutaber District, Ethiopia: Prevalence, sand fly fauna and community knowledge, attitude and practices.

Background: Cutaneous leishmaniasis (CL) affects 25% of the population living in the highlands of Ethiopia. CL intervention has not decreased the number of leishmaniasis patients. A cross-sectional study was conducted to determine CL prevalence, community's knowledge, attitude and practices (KAP), and the sand fly fauna in Kutaber district, northeast Ethiopia. Methods: A retrospective, community-based cross-sectional study was conducted in Boru Meda Hospital from December 2014-March 2021 to study CL prevalence of Kutaber district. A Pre-tested, well-structured questionnaire was used to collect data on the participants' socio-demographic characteristics, KAP towards CL and knowledge about sand fly vectors. Chi-square test and logistic regression analysis were used in the study, and data were analyzed using SPSS version 23 (p < 0.05). Results: A total of 10,002 (14.02%), of which 71,325 samples were confirmed as positive for CL. The infection rate of CL in females (7.1%) was a little bit higher than males (7.0%). More cases were recorded among 15-29 age category. The study also revealed that 77.1% of the respondents had poor knowledge about CL treatment, prevention, clinical presentation and disease transmission. Farmers tended to have poorer knowledge about sand flies than non-workers and students (32.7 vs. 35 and 44.1%; P = 0.049). Housewives had poorer knowledge about sand flies than farmers and workers (22.2 vs. 32.7 and 33.3%; P = 0.023). Phlebotomus longipes comprised the highest composition (80%) of the sand fly species identified in Kutaber district. Conclusions: The data showed that the community had poor knowledge about CL, vector, and transmission mode. CL preventive measures were prevalent, implying the need to raise CL awareness. Phlebotomus longipes was identified as the most dominant sand fly species which accounted for CL. The findings can be used in developing an effective control strategy to reduce CL transmission in the study area and elsewhere in Ethiopia.

Sero-prevalence of visceral leishmaniasis and its associated factors among asymptomatic individuals visiting Denan health center, southeastern Ethiopia.

BACKGROUND: In the Somali region of Ethiopia, visceral leishmaniasis (VL) is a public health concern. However, VL epidemiology and sand fly vectors have not been well studied in various areas of the regional state, including Denan district. Therefore, this study was conducted to determine the sero-prevalence, associated factors, and distribution of sand fly vectors of VL in Denan district, south-eastern Ethiopia. METHODS: A facility-based cross-sectional study was conducted from April to September 2021 among VL patients with classic signs and symptoms visiting Denan Health Center in south-eastern Ethiopia. Using a convenience sampling method, 187 blood samples were collected from individuals who visited Denan Health Center during the study period. Blood samples were subjected to Direct Agglutination Test for the detection of antibodies to VL. A pre-tested structured questionnaire was also used to gather information on risk factors and other characteristics of knowledge and attitude assessment. Sand flies were also collected from indoor, peri-domestic, mixed forest, and termite mounds using light and sticky traps to determine the fauna and abundance. RESULTS: The overall sero-prevalence rate was 9.63% (18/187). The sero-prevalence was significantly associated with outdoor sleeping (OR = 2.82), the presence of damp floors (OR = 7.76), and sleeping outdoor near animals (OR = 3.22). Around 53.48% of the study participants had previously heard about VL. Study participants practiced different VL control methods, including bed nets (42%), insecticide spraying (32%), smoking plant parts (14%), and environmental cleaning (8%). In total, 823 sand fly specimens, comprising 12 species in two genera (Phlebotomus and Sergentomyia), were trapped and identified. The most abundant species was Sergentomyia clydei (50.18%), followed by Phlebotomus orientalis (11.42%). Also, a higher proportion of P. orientalis was found in termite mounds (65.43%), followed by mixed forest (37.8%) and peri-domestic (20.83%) habitats. CONCLUSION: The study demonstrated a 9.63% sero-positivity of VL and a remarkable gap in knowledge, attitude, and practices towards VL. P. orientalis was also detected, which could be a probable vector in this area. Thus, public education should be prioritized to improve the community's awareness of VL and its public health impact. In addition, detailed epidemiological and entomological studies are recommended.

Performance of Urine Reagent Strips in Detecting the Presence and Estimating the Prevalence and Intensity of Schistosoma haematobium Infection.

The performance of the urine reagent strips (URS) in detecting the presence and estimating the intensity of Schistosoma haematobium infection was evaluated using urine filtration microscopy as a reference standard. Urine samples collected from 1288 school-age children living in five villages of the Afar and one village in the Gambella Regional States of Ethiopia between October 2021 and April 2022 were examined using urine filtration and URS. The prevalence of S. haematobium infection was 31.6% based on urine filtration and 32.1% using URS. Using results of the urine filtration as a reference, the sensitivity, specificity, negative predictive values, and accuracy of the URS in detecting S. haematobium egg-positive urine specimens were 73.7%, 87.8%, 87.1%, and 82.8%, respectively. Sensitivity increased significantly with an increase in the urine egg count. Specificity was greater in low prevalence settings and among children aged 5-9 years. The level of hematuria detected was trace (19.1%), weak (30.2%), moderate (36.0%), or high (14.7%). The log odds of showing higher-level hematuria significantly increased as the number of egg counts in urine increased. In conclusion, URS remains good in rapidly screening individuals for S. haematobium infection, but the sensitivity of the test could be lower, particularly when the intensity of the infection is light.

Intestinal helminthiasis survey with emphasis on schistosomiasis in Koga irrigation scheme environs, northwest Ethiopia.

BACKGROUND: Distribution of schistosomiasis is more focal due to spatial heterogeneities in intermediate host snail dynamics and water contact behavior of humans. This makes the search for new transmission foci of schistosomiasis and its connection with malacologically receptive water bodies essential for effective control of its transmission. This study was intended to assess the prevalence of intestinal helminth infections among schoolchildren and Schistosoma mansoni transmission in Koga irrigation scheme surroundings, northwest Ethiopia. MATERIALS AND METHODS: Cross-sectional parasitological and malacological surveys were conducted in three schools and nearby water bodies, respectively around Koga irrigation scheme. Stool specimens were collected from 421 randomly selected schoolchildren and microscopically examined using Kato-Katz and formol-ether concentration methods. Malacological surveys were carried out and the identified Biomphalaria pfeifferi snails were screened for schistosome infection. Swiss albino mice were exposed to schistosome cercariae shed by Biomphalaria pfeifferi for definite identification of Schistosoma species. RESULTS: Among the examined schoolchildren, 22.6% (95% CI: 18.7%-26.9%) were positive for at least one intestinal helminths species. Ascaris lumbricoides was the most frequent intestinal helminth detected among forty (9.5%) children. Schistosoma mansoni was detected among 4.8% (95% CI: 2.9%-7.2%) of children and its prevalence was significantly higher among male children (p = 0.038) and those attending in Mengesha Jemberie Primary School (p = 0.044). Biomphalaria pfeifferi snails were identified in water bodies in close proximity to Mengesha Jemberie and Wotete Abay Primay schools. Schistosoma mansoni adult worms were harvested after exposure of mice to cercariae shed from Biomphalaria pfeifferi snails collected from water bodies nearby Mengesha Jemberie Primary School. CONCLUSIONS: Schistosoma mansoni infection of schoolchildren, findings of schistosome infected snails and establishment of mice infection confirm that transmission is taking place in the study areas. Hence, snail control and other measures such as provision of sanitary facilities and health education are recommended.

Intestinal Helminth Infection, Anemia, Undernutrition and Academic Performance among School Children in Northwestern Ethiopia.

This study examined the prevalence and intensity of intestinal helminth infections and their association with anemia, undernutrition, and academic performance among school children in Maksegnit, northwestern Ethiopia. A total of 1205 school children, who attended Maksegnit Number Two Elementary School between May and July 2021, participated in this study. To determine helminth infection status, two thick Kato-Katz slides were examined for each child. Hemoglobin level was measured using a HemoCue machine. Academic performance was assessed using the mean score of all subjects children have taken for the Spring 2020/2021 academic term. Out of 1205 children examined, 45.4% were infected with at least one helminth species, 7.9% were anemic, and 35.8% were undernourished. The means for hemoglobin level and z-scores of weight for age, height for age, body mass index for age, and academic scores were lower among helminth-infected children than the uninfected. Children infected with intestinal helminths showed higher odds of anemia than those uninfected with helminths. In conclusion, there was a moderate prevalence of intestinal helminth infection and undernutrition among school children in Maksegnit. Intestinal helminth infection could increase the risk of anemia, undernutrition, and poor academic performance.

Residual efficacy of Fludora Fusion against Anopheles arabiensis in simple huts in Ethiopia.

Emergence and spread of malaria vectors resistant to the available insecticides required a new and efficacious insecticide. Residual efficacy of Fludora® Fusion was evaluated against insecticide susceptible Anopheles arabiensis in ten circular huts similar to the residential huts. Fludora® Fusion WP-SB 56.25, FICAM WP80 and Clothianidin WG70 were sprayed, by experienced technician, on interior wall surfaces: paint, dung, smooth mud, and rough mud. WHO cone bioassays were carried out a month after spraying and thereafter on monthly intervals for 12 months. Knockdown was recorded at 60 minutes and mortality at 24 hours, 48 hours and 72 hours holding time post-exposure. Fludora Fusion induced 100% An. arabiensis mortality during the first four months post-treated on all surface types at 24 hours holding time post-exposure. Its activity remained over 80% from the fifth to the twelfth month post-treated on the surfaces with the exception of two assessment points, at seventh month and eleventh month, on paint and smooth mud surfaces. FICAM induced 100% mortality rate during the first 4 months and 92% mortality during the fifth month post-treatment on painted surfaces. Its activity was over 96% mortality 1-month post-treatment on smooth mud and rough mud surfaces and 92% mortality 2-month post-treatment on dung surfaces. Clothianidin caused 89% and 86% mortality 1-month post-treatment on smooth mud and rough mud surfaces. Fludora Fusion can be used as alternative indoor residual insecticide spraying against An. arabiensis in Ethiopia.

Evidence of pyrethroid resistance in Anopheles amharicus and Anopheles arabiensis from Arjo-Didessa irrigation scheme, Ethiopia.

BACKGROUND: Indoor residual spraying and insecticide-treated nets are among the key malaria control intervention tools. However, their efficacy is declining due to the development and spread of insecticide resistant vectors. In Ethiopia, several studies reported resistance of An. arabiensis to multiple insecticide classes. However, such data is scarce in irrigated areas of the country where insecticides, pesticides and herbicides are intensively used. Susceptibility of An. gambiae s.l. to existing and new insecticides and resistance mechanisms were assessed in Arjo-Didessa sugarcane plantation area, southwestern Ethiopia. METHODS: Adult An. gambiae s.l. reared from larval/pupal collections of Arjo-Didessa sugarcane irrigation area and its surrounding were tested for their susceptibility to selected insecticides. Randomly selected An. gambiae s.l. (dead and survived) samples were identified to species using species-specific polymerase chain reaction (PCR) and were further analyzed for the presence of knockdown resistance (kdr) alleles using allele-specific PCR. RESULTS: Among the 214 An. gambiae s.l. samples analyzed by PCR, 89% (n = 190) were An. amharicus and 9% (n = 20) were An. arabiensis. Mortality rates of the An. gambiae s.l. exposed to deltamethrin and alphacypermethrin were 85% and 86.8%, respectively. On the other hand, mortalities against pirmiphos-methyl, bendiocarb, propoxur and clothianidin were 100%, 99%, 100% and 100%, respectively. Of those sub-samples (An. amharicus and An. arabiensis) examined for presence of kdr gene, none of them were found to carry the L1014F (West African) allelic mutation. CONCLUSION: Anopheles amharicus and An. arabiensis from Arjo-Didessa sugarcane irrigation area were resistant to pyrethroids which might be synergized by extensive use of agricultural chemicals. Occurrence of pyrethroid resistant malaria vectors could challenge the ongoing malaria control and elimination program in the area unless resistance management strategies are implemented. Given the resistance of An. amharicus to pyrethroids, its behavior and vectorial capacity should be further investigated.

Impact of sugarcane irrigation on malaria vector Anopheles mosquito fauna, abundance and seasonality in Arjo-Didessa, Ethiopia.

BACKGROUND: Despite extensive irrigation development in Ethiopia, limited studies assessed the impact of irrigation on malaria vector mosquito composition, abundance and seasonality. This study aimed to evaluate the impact of sugarcane irrigation on species composition, abundance and seasonality of malaria vectors. METHODS: Adult Anopheles mosquitoes were collected using CDC light traps from three irrigated and three non-irrigated clusters in and around Arjo-Didessa sugarcane irrigation scheme in southwestern Ethiopia. Mosquitoes were surveyed in four seasons: two wet and two dry, in 2018 and 2019. Mosquito species composition, abundance and seasonality were compared between irrigated and non-irrigated clusters. Anopheles mosquitoes were sorted out to species using morphological keys and molecular techniques. Chi square was used to test the relationships between Anopheles species occurrence, and environmental and seasonal parameters. RESULTS: Overall, 2108 female Anopheles mosquitoes comprising of six species were collected. Of these, 92.7% (n = 1954) were from irrigated clusters and 7.3% (n = 154) from the non-irrigated. The Anopheles gambiae complex was the most abundant (67.3%) followed by Anopheles coustani complex (25.3%) and Anopheles pharoensis (5.7%). PCR-based identification revealed that 74.7% (n = 168) of the An. gambiae complex were Anopheles arabiensis and 22.7% (n = 51) Anopheles amharicus. The density of An. gambiae complex (both indoor and outdoor) was higher in irrigated than non-irrigated clusters. The overall anopheline mosquito abundance during the wet seasons (87.2%; n = 1837) was higher than the dry seasons (12.8%; n = 271). CONCLUSION: The ongoing sugarcane irrigation activities in Arjo-Didessa created conditions suitable for malaria transmitting Anopheles species diversity and abundance. This could drive malaria transmission in Arjo-Didessa and its environs in both dry and wet seasons. Currently practiced malaria vector interventions need to be strengthened by including larval source management to reduce vector abundance in the irrigated areas.

Antimalarial activity of hydromethanolic extract and its solvent fractions of Vernonia amygdalina leaves in mice infected with Plasmodium berghei.

BACKGROUND: Vernonia amygdalina Del. (Asteraceae) is reported to be traditionally used for the treatment of malaria. Based on folkloric repute of this plant in Ethiopian traditional medicine and crude extract-based ethnopharmacological studies conducted in few countries, this study was undertaken to evaluate the in vivo antimalarial activity of 80% methanol extract and its solvent fractions of the leaves of V. amygdalina in mice infected with Plasmodium berghei. METHODS: A 4-day suppressive test was conducted on mice infected with P. berghei to find out antimalarial effect of chloroform, butanol and aqueous fractions obtained from the 80% methanol crude extract. In all the activity tests, mice were randomly assigned in five groups (three tests and two controls) of six animals in each and received respective treatments. Data were analyzed using one way analysis of variance followed by Tukey's post hoc test for multiple comparisons. RESULTS: Acute oral toxicity test showed that all solvent fractions of the leaves of V. amygdalina revealed neither mortality nor overt signs of toxicity up to 2000 mg/kg. This study indicated that the percentage parasitemia suppression of 80% methanol extract was 32.47% (±2.65), 35.40% (±3.14) and 37.67% (±2.50) at 200, 400 and 600 mg/kg, respectively. All doses of the 80% methanol extract of V. amygdalina prolonged survival time and prevented weight loss and packed cell volume reduction in infected mice. All doses of chloroform and butanol fractions significantly suppressed parasitemia (p < 0.05), increased survival time (p < 0.05) compared to negative control and exhibited a significant reduction in rectal temperature (p < 0.05). All solvent fractions significantly prevented weight loss (p < 0.05) at all tested doses. The 80% methanol extract and chloroform and butanol fractions significantly (p < 0.05) prevented further reduction in rectal temperature of P. berghei-infected mice at all doses. CONCLUSION: The results of this study indicated that 80% methanol extract and solvent fractions of the leaves of V. amygdalina demonstrated promising antimalarial activity. The study corroborated the folklore use of this plant for the treatment of malaria in ethnomedicine in Ethiopia.

Dry season occurrence of Anopheles mosquitoes and implications in Jabi Tehnan District, West Gojjam Zone, Ethiopia.

BACKGROUND: Generating evidence on the dry season occurrence of the larval and adult stages of Anopheles mosquitoes helps to design effective malaria vector control strategy as the populations of the vectors is expected to be low. METHODS: Larval and adult stages of Anopheles were surveyed during dry seasons in Mender Meter, Jiga Yehlmidar and Wongie Berkegn villages, Jabi Tehnan District, West Gojjam Zone, Ethiopia. Larvae were surveyed (along the available surface water collections), sampled, identified into genus, counted and late instars of the genus Anopheles identified into species. Indoor-resting adult mosquitoes were collected using insecticide aerosol spray, processed and identified into species. Data was analysed using SPSS version 20.0 to determine frequencies, mean differences and associations. RESULTS: A total of 3127 Anopheles larvae were collected among which most (91.7%; 2869/3127) were from streams followed by ponds (4.3%; 136/3127) and swamps (3.9%; 122/3127). Anopheles gambiae sensu lato was the most prevalent (84.9%; 921/1085) followed by Anopheles cinereus (7.0%; 76/1085), Anopheles chrysti (3.7%; 40/1085), Anopheles demeilloni (2.8%; 30/1085) and Anopheles rhodesiensis (1.6%; 18/1085). The mean number (mean = 15.3) of An. gambiae from Jiga Yehlmidar was significantly (p = 0.024) higher than the corresponding number (mean = 3.2) from Mender Meter. The mean number (mean = 36.3) of An. gambiae larvae in April 2017 was significantly (p = 0.001) higher than the number (mean = 4.0) in December 2013 and the number (mean = 2.6) in March 2013. A total of 1324 adult Anopheles were collected of which the highest proportion (79.1%; 1048/1324) was An. gambiae, followed by An. chrysti (11.7%; 155/1324), An. demeilloni (6%; 80/1324), An. cinereus (2.6%; 35/1324) and Anopheles coustani (0.5%; 6/1324). The highest proportion (54.3%; 569/1048) of the An. gambiae was collected from Wongie Berkegn followed by Jiga Yehlmidar (23.6%; 247/1048) and Mender Meter (22.1%; 232/1048). The mean number (mean = 7.8) of adult An. gambiae caught in Wongie Berkegn was significantly (p = 0.018) higher compared to the number (mean = 3.0) in Mender Meter. No significant difference was observed in the mean number of adult An. gambiae between the seasons. CONCLUSION AND IMPLICATION: Streams were prolific breeding habitats of Anopheles mosquitoes followed by ponds and swamps in the dry seasons. In addition, a high population of indoor resting An. gambiae was caught from indoors. This implies the need for a strengthened vector control during dry seasons using breeding habitat management and improved housing in addition to the existing insecticide (LLINs and IRS) based interventions in Jabi Tehnan District, West Gojjam Zone, Ethiopia.

Use of epidemiological and entomological tools in the control and elimination of malaria in Ethiopia.

Malaria is the leading public health problem in Ethiopia where over 75% of the land surface is at risk with varying intensities depending on altitude and season. Although the mortality because of malaria infection has declined much during the last 15-20 years, some researchers worry that this success story may not be sustainable. Past notable achievements in the reduction of malaria disease burden could be reversed in the future. To interrupt, or even to eliminate malaria transmission in Ethiopia, there is a need to implement a wide range of interventions that include insecticide-treated bed nets, indoor residual spraying, improved control of residual malaria transmission, and improved diagnostics, enhanced surveillance, and methods to deal with the emergence of resistance both to drugs and to insecticides. Developments during the past years with increasing awareness about the role of very low levels of malaria prevalence can sustain infections, may also demand that tools not used in the routine control efforts to reduce or eliminate malaria, should now be made available in places where malaria transmission occurs.

Ethnobotanical survey of antimalarial plants in Awash-Fentale District of Afar Region of Ethiopia and in vivo evaluation of selected ones against Plasmodium berghei

Objective:To document plants used in traditional treatment of malaria in the Awash-Fentale District,the Afar Region of Ethiopia,and to evaluate antimalarial activity of selected ones against Plasmodium berghei in mice.Methods:Semi-structured interviews were carried out with purposively selected informants in the District to gather information on plants used in the traditional treatment of malaria.Standard procedures were used to investigate acute toxicity and a four-day suppressive effect of cmde aqueous and ethanol extracts of the leaves of the two most frequently cited plants [Aloe trichosantha (A.trichosantha) and Cadaba rotundifolia (C.rotundifolia)] against Plasmodium berghei in Swiss albino mice.Results:The informants cited a total of 17 plants used in the traditional treatment of malaria in Awash-Fentale District.Plant parts were prepared as infusions or decoctions.Leaf was the most commonly cited (44％) plant part,followed by stem (22％).Shrubs were the most frequently cited (63％) medicine source followed by trees (21％).Of the 17 plants,C.rotundifolia and A.trichosantha were the most frequently mentioned plants in the district.Ethanol extracts of the leaves of C.rotundifolia and A.trichosantha suppressed P.berghei parasitaemia significantly accounting for 53.73％ and 49.07％,respectively at 900 mg/kg.The plants were found to be non-toxic up to a dose of 1 500 mg/kg.Conclusions:Seventeen plant species were reported to be used for treatment of malaria in the Awash Fentale Distinct,among which A.trichosantha and C.rotundifolia were the most preferred ones.P.berghei suppressive activity of these plants may partly explain their common use in the community.

Assessment of Clarias gariepinus as a biological control agent against mosquito larvae.

BACKGROUND: The emergence and spread of insecticide resistant mosquitoes renewed interest in investigating the use of larvivorous fish as a biological control agent. The potential of Clarias gariepinus fish in controlling Anopheles arabiensis and culicine larvae was assessed under laboratory and semi-field conditions. RESULTS: Small size (15-20 cm) C. gariepinus fish consumed greater number of mosquito larvae than the large size fish (25-40 cm) in the multivariate regression model (ß = 13.36, 95 % CI = 4.57, 22.15). The Anopheles larvae consumed was greater in number than the culicines larvae consumed by the fish (ß = 12.10, 95 % CI = 3.31, 20.89). The number of larvae consumed was greater during the night hours than during the light hours (ß = 30.06, 95 % CI = 21.27, 38.85). Amount of supplementary fish food did not cause significant differences in the number of mosquito larvae consumed by the fish among different groups. C. gariepinus was observed to feed on mosquito larvae under laboratory and semi-field conditions. CONCLUSION: C. gariepinus fed on the larvae of An. arabiensis and culicines readily. Hence, it can be used as an alternative mosquito control agent in Ethiopia where the breeding habitats are small and localized.