An epidemiological assessment of the residual effect of DDT on Anopheles hyrcanus sensulato and A. Pulcherrimus (Theobold) in the North eastern Region of Afghanistan

Abstract

In the irrigated zones of North-eastern region of Afghanistan malaria transmission is sustained by A. pulcherrimus and A. hyrcanus despite many years of DDT spraying. A. hyrcanus is an exophilic and exophagic mosquito, strongly resistant to DDT. A. pulcherrimus is still largely susceptible to the insecticide but seems to be deterred from entering houses when these are sprayed with DDT. Entomological and parasitological studies in an area of the province of Kunduz where DDT has not been applied for 2 consecutive years have clearly indicated that the insecticide still plays an important role in reducing malaria transmission in the area though, as expected, it cannot interrupt transmission. A deterioration of the epidemiological situation in the area can be expected if the insecticide is withdrawn. The technical problems now existing in the irrigated zones of the North-eastern region of Afghanistan cannot be solved by routine attack measures. Malaria in the area can be eradicated only with the introduction of new attack measures which are very expensive and for which, at present, the necessary funds are not available.

Malaria control under the Taliban regime: insecticide-treated net purchasing, coverage, and usage among men and women in eastern Afghanistan

“…During the malaria eradication era of the 1950s and 1960s, IRS was widely and successfully applied in Afghanistan [52,53]. IRS and effective treatment drugs, as parasites were not yet resistant to chloroquine, led to low malaria prevalence in most parts of the country [54].…”

Malaria Reemergence in Northern Afghanistan

“…This may be due to various factors: 1) introduction of P. falciparum and P. vivax malaria by returning refugees ( 13 ); 2) environmental changes caused by intensified rice growing in close proximity to towns, villages, and housing areas and therefore within flight range of endemic anopheline vectors ( 3 , 5 ); 3) increased abundance and breeding of the local principal vectors of P. vivax malaria stemming from intensified rice growing and irrigation systems that serve as preferred breeding sites for A. pulcherrimus and A. hyrcanus ( 3 , 5 ); and 4) absence of widespread biological and chemical vector control measures, including effective larviciding in flooded rice fields ( 8 ). …”

“…At that time, vivax malaria chiefly occurred in the irrigated zones of northeastern Afghanistan ( 3 ). Rice fields were located > 5 km away from villages to exceed the flight range of vector-competent, widely DDT-resistant anopheline mosquitoes, and larvivorous Gambusia affinis fish were continuously reared and widely introduced ( 5 , 6 ). After 1980, chronic political instability resulted in the progressive breakdown of malaria control activities ( 2 ).…”

Effects of Local Anthropogenic Changes on Potential Malaria VectorAnopheles hyrcanusand West Nile Virus VectorCulex modestus,Camargue, France

“…It is distributed from Spain to People’s Republic of China, covering the southern half of Europe, the Mediterranean area, and central Asia. Large populations are found in irrigated rice-growing areas in Turkey, Greece, and France ( 23 , 24 ), and this species was involved in malaria transmission in the north of Afghanistan ( 25 ). …”