RESUMO
Background: In late 2021, Ghana was hit by a Yellow Fever outbreak that started in two (2) districts in the Savannah region and spread to several other Districts in (3) regions (Oti, Bono and Upper West).Yellow fever is endemic in Ghana. However, there is currently no structured vector control programme for the yellow vector, Aedes mosquitoes in Ghana. Knowledge of Aedes bionomics and insecticide susceptibility status is important to control the vectors. This study therefore sought todetermine Aedes vector bionomics and their insecticide resistance status during a yellow fever outbreak. Methods: The study was performed in two yellow fever outbreak sites (Wenchi, Larabanga) and two non-outbreak sites (Kpalsogu, Pagaza) in Ghana. Immature Aedes mosquitoes were sampled from water-holding containers in and around human habitations. The risk of disease transmission was determined in each site using stegomyia indices. Adult Aedes mosquitoes were sampled using Biogents Sentinel (BG) traps, Human Landing Catch (HLC), and Prokopack (PPK) aspirators. Phenotypic resistance was determined with WHO susceptibility tests using Aedes mosquitoes collected as larvae and reared into adults. Knockdown resistance (kdr) mutations were detected using allele-specific multiplex PCR. Results: Of the 2,664 immature Aedes sampled, more than 60% were found in car tyres. Larabanga, an outbreak site, was classified as a high-risk zone for the Yellow Fever outbreak (BI: 84%, CI: 26.4%). Out of 1,507 adult Aedes mosquitoes collected, Aedes aegypti was the predominant vector species (92%). A significantly high abundance of Aedes mosquitoes was observed during the dry season (61.2%) and outdoors (60.6%) (P < 0.001). Moderate to high resistance to deltamethrin was observed in all sites (33.75% to 70%). Moderate resistance to pirimiphos-methyl (65%) was observed in Kpalsogu. Aedesmosquitoes from Larabanga were susceptible (98%) to permethrin. The F1534C kdr, V1016I kdr and V410 kdr alleles were present in all the sites with frequencies between (0.05-0.92). The outbreak sites had significantly higher allele frequencies of F1534C and V1016I respectively compared to non-outbreak sites (P < 0.001). Conclusion: This study indicates that Aedes mosquitoes in Ghana pose a significant risk to public health, and there is a need for continuous surveillance to inform effective vector control strategies.
RESUMO
Background: In sub-Saharan Africa, malaria, chronic viral diseases, nutritional deficiencies, and haemoglobinopathies are common causes of anaemia. Continual surveillance data is required to situate the anaemia and infectious disease burden within a given population. This study determined the 4-year trends of anaemia, hepatitis B virus (HBV), and HCV infections and factors associated with anaemia in young Ghanaian adults. Methods: This retrospective study analysed the medical records of 21,716 fresh students at the University of Cape Coast. Data was presented as percentages and line graphs to show the yearly trends in anaemia, HBV, and HCV infections. Binary logistic regression was used to determine the increased odds of anaemia in participants. Results: Although the 4-year anaemia prevalence was 14.2% (95% CI: 0.1403-0.1498), anaemia prevalence in women and men were 24.1% (95% CI: 0.2387-0.2562) and 6.6% (95% CI:0.0616-0.0705), respectively. Anaemia prevalence consistently remained mild (males) and moderate (females) public health problem over the four-year period. Adolescents were more represented in the anaemic group (18.7% prevalence), 70.9% of them being females. The prevalence of HBV and HCV infections were 5.4% (95% CI:0.0506-0.0567) and 0.9% (95% CI: 0.0082-0.0108), respectively; only 0.1% of participants had HBV and HCV coinfection. Males were more represented in both HBV (71.2%) and HCV (63.7%) infection groups. Moreover, 15.8% of the participants who were seropositive for HBsAg self-reported having previously been vaccinated, suggesting a breakthrough infection and/or vaccine nonresponse. Furthermore, female (COR: 4.545; p < 0.001), teenagers (COR: 1.697; p < 0.001), 20-29 years (COR: 1.221; p = 0.035), and positive sickling slide test (COR: 1.176; p = 0.003) were statistically significantly associated with increased odds of anaemia. Conclusion: Intentional preventative public health campaigns regarding anaemia, HBV, and HCV infection should, respectively, target females and young adult males to increase chances of making real change in behavioural attitudes in these at-risk groups.
