<I>Aedes</I> (<I>Ochlerotatus</I>) <I>epactius</I> Along an Elevation and Climate Gradient in Veracruz and Puebla States, México

Abstract

We report on the collection ofimmatures of Aedes (Ochlerotatus) epactius Dyar & Knab from artificial containers during July through September 2011 in 12 communities located along an elevation and climate gradient extending from sea level in Veracruz State to high elevations (>2,000 m) in Veracruz and Puebla States, México. Ae. epactius was collected from 11 of the 12 study communities; the lone exception was the highest elevation community along the transect (>2,400 m). This mosquito species was thus encountered at elevations ranging from near sea level in Veracruz City on the Gulf of México to above 2,100 m in Puebla City in the central highlands. Collection sites included the city of C6rdoba, located at approximately 850 m, from which some of the first described specimens of Ae. epactius were collected in 1908. Estimates for percentage of premises in each community with Ae. epactius pupae present, and abundance of Ae. epactius pupae on the study premises, suggest that along the transect in central México, the mosquito is present but rare at sea level, most abundant at mid-range elevations from 1,250-1,750 m and then decreases in abundance above 1,800 m. Statistically significant parabolic relationships were found between percentage of premises with Ae. epactius pupae present and average minimum daily temperature, cumulative growing degree-days, and rainfall. We recorded Ae. epactius immatures from a wide range of container types including cement water tanks, barrels/ drums, tires, large earthen jars, small discarded containers, buckets, cement water troughs, flower pots, cement water cisterns, and larger discarded containers. There were 45 documented instances of co-occurrence of Ae. epactius and Aedes aegypti (L.) immatures in individual containers.

How super-spreader cities, highways, hospital bed availability, and dengue fever influenced the COVID-19 epidemic in Brazil

“…According to our hypothesis, SARS-CoV-2 may have been able to outcompete DENV, and trigger a sudden decrease in dengue fever incidence all over the world after March 2020, primarily because it relies on human-to-human transmission, while dengue viruses depend mainly on mosquitos of the Aedes genus (Aedes aegypti and Aedes albopictus) for transmission. Given that the dengue's vector can only survive under certain climate conditions, like altitudes below 2,000 meters [19][20][21], SARS-CoV-2 would have a clear competitive advantage when introduced in a common ecological niche, being able to spread faster and infect a larger population of susceptible people, over a much larger territory, particularly in big cities. This seems to be confirmed by the fact that larger Brazilian cities exhibited much higher incidence of COVID-19 than dengue.…”

“…Simple visual inspection of these distributions reveals striking spatial patterns in each of them and also a clear dissimilarity. For instance, while by August 1 st most of the country was reporting a high number of COVID-19 cases, a larger incidence of fatalities was concentrated on the coastal state capitals and mediumsize interior towns (see (BRs 101,116,222,232,272,308,319,374,381,20,40,50,408,447,450,and 465) was highly correlated with the distribution of COVID-19 deaths across the whole country (Supplementary Table 2).…”

First report of Stegomyia aegypti (= Aedes aegypti) in Mexico City, Mexico

“…However, the most recent survey indicated the intermittent presence of S. aegypti at 2130 m a.s.l. in Puebla State (Lozano‐Fuentes et al ., , ). Consequently, Mexican control programmes have adopted monitoring and surveillance schemes in localities in which the presence of the mosquito is unlikely, such as in Mexico City.…”

“…(Ibanez-Bernal, 1987;Herrera-Basto et al, 1992). However, the most recent survey indicated the (Lozano-Fuentes et al, 2012, 2014. Consequently, Mexican control programmes have adopted monitoring and surveillance schemes in localities in which the presence of the mosquito is unlikely, such as in Mexico City.…”

“…The climatic factors associated with its geographical location should make Mexico City presumably unsuitable for colonization and population growth of S. aegypti (Lozano‐Fuentes et al ., ; Cetron, ). However, demographic changes to the city and its relevance as a financial, cultural and business hub may be causative factors in the introduction of the mosquito.…”