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Dengue Fever (DF) is an important arthropod-borne viral infection, which has repeatedly oc-curred as outbreaks in eastern and northeastern Ethiopia since 2013. A cross-sectional epidemio-logical outbreak investigation was carried out from September - November 2019 on febrile pa-tients (confirmed malaria negative) who presented with suspected and confirmed DF at both public and private health facilities in Gewane District, Afar Region, northeastern Ethiopia. Ento-mological investigation of containers found in randomly selected houses belonging to DF positive patients was undertaken, to survey for the presence of Aedes larvae or pupae. A total of 1185 DF cases was recorded from six heath facilities during the 3-month study period. The mean age of DF cases was 27.2 years and 42.7% of the cases were female. The most affected age group was 15-49 years (78.98%). However, the attack rate (AR) was highest in the 49+ age group (134.2). A total of 162 artificial containers were inspected from 62 houses, with 49.4% found positive for Aedes larva/pupae. Aedes mosquitoes were mostly found breeding in buckets/bowls, clay jars, plastic tanks, and tires. World Health Organization entomological indices classified the study site as high risk for dengue outbreaks (House Index=45.2%, Container Index=49.4% and Breteau In-dex=129). Study findings highlight the importance of vector control to prevent future dengue out-breaks in the region. The scarcity of drinking water and changing climactic conditions may have also contributed to the occurrence of this outbreak.

Background. Chikungunya virus is a ribonucleic acid (RNA) virus transmitted by a mosquito bite. Chikungunya virus outbreaks are characterized by rapid spread, and the disease manifests as acute fever. This study aimed at determining risk factors for chikungunya virus outbreak to apply appropriate prevention and control measures. Methods. Unmatched case-control study was performed to identify risk factors of chikungunya outbreak in Somali region of Ethiopia in 2019. Cases and controls were enrolled with 1 : 2 ratio. All cases during the study period (74 cases) and 148 controls were included in the study. Bivariate and multivariable analyses were implemented. The serum samples were tested by real-time polymerase chain reaction at Ethiopian Public Health Institute Laboratory. Results. A total of 74 chikungunya fever cases were reported starting from 19th May 2019 to 8th June 2019. Not using bed net at daytime sleeping (adjusted odds ratio (AOR): 20.8; 95% confidence interval (CI): 6.4–66.7), presence of open water holding container (AOR: 4.0; CI: 1.2–3.5), presence of larvae in water holding container (AOR: 4.8; CI: 1.4–16.8), ill person with similar signs and symptoms in the family or neighbors (AOR: 27.9; CI: 6.5–120.4), and not wearing full body cover clothes (AOR: 8.1; CI: 2.2–30.1) were significant risk factors. Conclusion. Not using bed net at daytime sleeping, presence of open water holding container, presence of larvae in water holding container, ill person with similar signs and symptoms in the family or neighbors, and not wearing full body cover clothes are risk factors for chikungunya virus outbreak.

In Ethiopia, malaria incidence has significantly reduced in the past decade through the combined use of conventional vector control approaches and treatment using antimalarial drugs. However, the sustainability of this achievement is threatened by the shift in biting and resting behaviors and emergence of insecticide resistance by the primary malaria vector. Therefore, continuous monitoring of the behaviour of malaria mosquitoes in different sentinel sites is crucial to design effective prevention and control methods in the local context. Entomological investigations were conducted in three sentinel sites for five consecutive months during the major malaria transmission season. The species composition, population dynamics, biting and resting behaviours of malaria vectors were determined using center for disease control and prevention (CDC) light trap, human landing catch (HLC), pyrethrum spray catch (PSC) and Pitfall shelter collection (PFS). Accordingly, 10 households for CDC, 10 households for PSC, 10 households for PFS and 5 households for HLC from each site were randomly enrolled for mosquito collection. A total of 8,297 anopheline mosquitoes were collected from the three sites, out of which 4,525 (54.5 %) were

In Ethiopia, malaria incidence has significantly reduced in the past decade through the combined use of conventional vector control approaches and antimalarial drugs. However, the sustainability of this achievement is threatened by the shift in biting and resting behaviors and emergence of insecticide resistance by the primary malaria vector. Therefore, continuous monitoring of the behaviour of malaria mosquitoes in different sentinel sites is crucial to design effective prevention and control methods in the local context. Entomological investigations were conducted in three sentinel sites for five consecutive months during the major malaria transmission season. The species composition, population dynamics, biting and resting behaviours of malaria vectors were determined using center for disease control and prevention (CDC) light trap, human landing catch (HLC), pyrethrum spray catch (PSC) and Pit shelter collection (PFS). Accordingly, 10 households for CDC, 10 households for PSC, 10 households for PFS and 5 households for HLC from each site were randomly enrolled for mosquito collection. A total of 8,297 anopheline mosquitoes were collected from the three sites, out of which 4,525 (54.5%) were An. gambiae, s.l. 2,028 (24.4%) were An. pharoensis, 160 (1.9%) were An. funestus and the rest 1,584 (19%) were other Anophelines (An. coustani, An. cinerus and An. tenebrosus). No significant variation (P = 0.476) was observed between indoor (25.2/trap-night and outdoor collections (20.1/trap-night). Six hundred seventy six (43.3%) of An. gamiabiae s.l. (primary vector) were collected between 18:00 and 22:00 hours. Biting activity declined between 00:00 and 02:00 hours. The national malaria control program should pay close attention to the shifting behavior of vector mosquitoes as the observed outdoor feeding tendency of the vector population could pose challenges to the indoor intervention tools IRS and LLINs. Funding Information: This work was supported by the Ministry of health (Global fund). Declaration of Interests: The authors declare that they have no conflicts of interest. Ethics Approval Statement: This study was issued ethical clearance by the Scientific and Ethical Review Committee (SERC) in Ethiopia Public Health Institute with reference number EPHI 6.13/976. Verbal consent was obtained from the heads of households before commencing mosquito collection in houses. The heads of households surveyed were informed that participation in the study was absolutely voluntary and that even after consenting they would be free to withdraw from the study at any time.

House is the major site for malaria infection where most human-vector contact takes place. Hence, improving housing might reduce the risk of malaria infection by limiting house entry of vectors. This study aimed to explore the impact of screening doors and windows with wire meshes on density and entomological inoculation rate (EIR) of malaria vector, and malaria incidence, and assess the acceptability, durability, and cost of the intervention. The susceptibility status of malaria vector was also assessed. A two-arm randomized trial was done in Arba Minch Town, southwest Ethiopia. 92 houses were randomly included in the trial. The baseline entomological and malaria prevalence data were collected. The mosquito sampling was done twice per household per month by Centers for Diseases Control and Prevention (CDC) light traps for six months. The baseline prevalence of malaria was assessed by testing 396 (83% of the 447 study participants) household members in all the eligible houses. The 92 houses were then randomized into control and intervention groups using mosquito and malaria prevalence baseline data to make the two groups comparable except the intervention. Then, we put wire-mesh on doors and windows of 46 houses. Post-screening mosquito collection was done in each household twice per month for three months. Each household member was visited twice per month for six months to assess malaria episodes. The frequency of damage to different structure of screening was measured twice. In-depth interview was conducted with 24 purposely selected household heads from intervention group. Speciation of Anopheles mosquito was done by morphological key, and the circum-sporozoite proteins (CSPs) analysis was done using enzyme-linked immunosorbent assay. A generalized estimating equation with a negative binomial distribution was used to assess the impact of the intervention on the indoor density of vectors. Clinical malaria case data were analyzed using Poisson regression with generalized linear model. Screening doors and windows reduced the indoor density of An. arabiensis by 48% (mean ratio of intervention to control = 0.85/1.65; 0.52) (P = .001). Plasmodium falciparum CSP rate was 1.6% (3/190) in the intervention houses, while it was 2.7% (10/372) in the control houses. The protective efficacy of screening intervention from CSP positive An. arabiensis was 41% (mean ratio of intervention to control = 1.6/2.7; 0.59), but was not statistically significant (P = .6). The EIR of An. arabiensis was 1.91 in the intervention group, whereas it was 6.45 in the control group. 477 participants were followed for clinical malaria (50.1% from intervention and 49.9% from the control group). Of 49 RDT positive cases, 45 were confirmed to be positive with microscopy. 80% (n = 36) cases were due to P. falciparum and the rest 20% (n = 9) were due to P. vivax . The incidence of P. falciparum in the intervention group was lower (IRR: 0.39, 95% CI: 0.2–0.80; P = .01) than in the control group. Using incidence of P. falciparum infection, the protective efficacy of intervention was 61% (95% CI: 18–83; P = .007). 97.9% of screened windows and 63.8% of screened doors were intact after eleven months of installation. Malaria mosquito was resistance (mortality rate of 75%) to the insecticide used for bed nets treatment. Almost all participants of intervention arm were willing to continue using screened doors and windows. Screening doors and windows reduced the indoor exposure to malaria vectors. The intervention is effective, durable and well-accepted. Hence, the existing interventions can be supplemented with house screening intervention for further reduction and ultimately elimination of malaria by reducing insecticide pressure on malaria vectors. However, further research could be considered in broad setting on different housing improvement and in the way how to scale-up for wider community.

Background: Coordinating outbreak investigations requires effective interagency communication. Important tasks include making the initial notifications, establishing roles and responsibilities for each jurisdiction, providing updates on the progress of the investigations, revising priorities for the investigation, and establishing the next steps. The major goal of surveillance activities is to identify and eliminate preventable causes of morbidity and mortality. Outbreak response basically entails preparedness which helps to establish arrangements in advance to enable timely, effective and appropriate responses to specific potential hazardous events or emerging disaster situations that might threaten society/environment Objective: To review lessons learned from the October 2018 Wolayta Zone yellow fever outbreak management in SNNPR, Ethiopia. Methods: Qualitative research approach, with Thematic Analysis. Purposive sampling method was used. Data were collected through FGDs, in-depth interviews, observation and document reviews Results : Among the main findings of the review is the weakness of the surveillance to detect case; the surveillance system was not that much effective for early detection of viral hemorrhagic fevers and there was knowledge gap to detect in the existing. The Review found out further that preparedness plan was weak, failing to consider the outbreak for VRAM. However, it is worth-noting that the Review showed that despite late detection, a rapid response team was set up and was able to save the lives of many during the outbreak. The findings further showed there was good coordination among various stakeholders at different levels and with satisfying sharing of roles and responsibilities. Conclusion: Based on the major findings, it may be concluded that the surveillance system was weak to detect yellow fever outbreak occurrence in Wolaita Zone. A major gap is therefore the inability to include the case to the IDSR weekly report. Once the case was confirmed, the response to the crisis was fairly commendable. Even though there was a confusion on identifying the first case, after the confirmation of the first case, the case management went as per the standard guideline and SOPs, helping save so many lives through availing the service free of charge Key terms: After Action Review; Outbreak Response; Yellow Fever, Surveillance, Coordination

House is the major site for malaria infection where most human-vector contact takes places. Hence, screening of houses might reduce the risk of malaria infection by limiting house entry of vectors. This study was assessed the impact of screening doors and windows on indoor density, sporozoite and entomological inoculation rate (EIR) of malaria vectors in malaria hotspot Kebeles (smallest administrative unit in Ethiopia) of Arba Minch town, southwest Ethiopia. The insecticide susceptibility status of Anopheles arabiensis was assessed. Pre-intervention mosquito collection was made by Center for Disease Control and Prevention (CDC) light traps from 92 randomly selected houses. The 92 households were randomized into control and intervention groups. The doors and windows of 46 houses were screened by wire-mesh. Post-intervention mosquito sampling was done by CDC light traps in intervention and control houses. Anopheles mosquitoes were identified into species using a morphological key, and then the circum- sporozoite proteins (CSPs) analysis was conducted using Enzyme-Linked Immuno-Sorbent Assay (ELISA). All the household members both in the intervention and control groups were screened for malaria parasite using a rapid diagnostic test. Anopheles larvae and pupae were collected from natural breeding habitats within the Kebeles, and 2-3 days old female An. arabiensis was tested for susceptibility to insecticide. Probit analysis was employed to calculate the knock down time of An. arabiensis. A Generalized Estimating Equations with a negative binomial distribution was used to see the impact of screening intervention by account for over dispersion of An. arabiensis counts and repeated catches made in the same house. There was a 48% reduction in indoor density of An. arabiensis and it was statistically significant (p = 0.001). The impact of house screening intervention was substantially high (69%) on unfed (active host- seeking) An. arabiensis than other abdominal stages. Plasmodium falciparum CSP rate was 1.6% in houses screened with wire-mesh and 2.7 % in control houses. Screening doors and windows reduced the sporozoite rate of An. arabiensis by 41%, but the reduction was not statistically significant (p>0.05). Screening doors and windows reduced the infectious bites of An. arabiensis by 70%, and the risk of receiving infectious bites was 3.3 times higher in control houses compared to the screened houses. House screening may not affect bed net use rate. Anopheles arabiensis has developed resistance to deltamethrin but was highly susceptible to bendiocarb, propoxur, and malathion. Finally, house screening intervention has played a substantial role byviii reducing the exposure to malaria vectors, and hence can be recommended as an important intervention to include in malaria vector control package.