Confirmation of the presence of Anopheles stephensi among internally displaced people's camps and host communities in Aden city, Yemen.

BACKGROUND: Declines in global malaria cases and deaths since the millennium are currently challenged by multiple factors including funding limitations, limits of, and resistance to vector control tools, and also recent spread of the invasive vector species, Anopheles stephensi-especially into novel urban settings where malaria rates are typically low. Coupled with general increases in urbanization and escalations in the number of conflicts creating rapid and unplanned population displacement into temporary shelter camps within host urban areas, particularly in the Middle East and sub-Saharan Africa, increased urban malaria is a major threat to control and elimination. METHODS: Entomological monitoring surveys (targeting Aedes aegypti) of water containers across urban areas hosting internally displaced people (IDP) communities in Aden city, Yemen, were performed by The MENTOR Initiative, a non-governmental organisation. As part of these surveys in 2021 23 larvae collected and raised to adults were morphologically identified as An. stephensi. Twelve of the samples were sent to Liverpool School of Tropical Medicine for independent morphological assessment and genetic analysis by sequencing the ribosomal ITS2 region and the mitochondrial COI gene. RESULTS: All twelve samples were confirmed morphologically and by sequence comparison of the single ITS2 and COI haplotype detected to the NCBI BLAST database as An. stephensi. Phylogenetic analysis with comparable COI sequences indicated close relationship to haplotypes found in Djibouti and Ethiopia. CONCLUSION: The study results confirm the presence of An. stephensi in Yemen. Confirmation of the species in multiple urban communities hosting thousands of IDPs living in temporary shelters with widescale dependency on open water containers is of particular concern due to the vulnerability of the population and abundance of favourable breeding sites for the vector. Proactive monitoring and targeted integrated vector management are required to limit impacts in this area of typically low malaria transmission, and to prevent further the spread of An. stephensi within the region.

[Antibiotics - In Which Fields is there Need for Action?] / Antibiotikaresistenz: In welchen Handlungsfeldern muss mehr getan werden?

For decades, antibiotics have been utilized successfully to treat infectious diseases. As part of a natural process, resistance mechanisms evolved in bacteria rendering some of these antibiotics ineffective. A significant increase in the use of antibiotics worldwide has greatly accelerated this process. As a result, treatment of many infectious diseases such as tuberculosis or gonorrhea has become increasingly difficult and nosocomial infections are causing great problems in health care systems. Many action plans and counter-measures have been developed but are seldom put into action and fail to address all problems related to antibiotic resistance. To ensure that antibiotics will remain a reliable option for treating infectious diseases, targeted action is needed in various fields.

What sounds like Aedes, acts like Aedes, but is not Aedes? Lessons from dengue virus control for the management of invasive Anopheles.

Aedes mosquitoes are responsible for transmission of dengue, chikungunya, Zika, and yellow fever viruses. Aedes mosquitoes are the pathfinders of invasive urban-living mosquitoes, and have spread into 129 countries over the past five decades. In the past 10 years Anopheles stephensi has been identified within densely populated cities in Yemen and across the Horn of Africa and as far west as Nigeria. A stephensi's aggressive spread is closely linked to increases in population movement due to migration, conflict, and climate change; rapid unplanned urbanisation; and resulting poor water quality, sanitation, waste container removal, and hygiene systems. As a highly invasive vector that is adept at transmitting malarial pathogens (eg, Plasmodium vivax and Plasmodium falciparum), A stephensi's spread holds huge implications for increasing malaria morbidity and mortality. Both vectors (ie, Aedes species and A stephensi) thrive in the same urban environments, and urgent action is needed to seize the opportunity to integrate disease control resources and generate innovative vector-control tools for urban populations, to protect the many millions at risk.