16.2 Arthropod-Borne Diseases
16.2.1 Malaria and West Nile Virus
Malaria is one of the oldest parasitic diseases of the country where it is recorded as
endemic (Vatandoost et al. 2019). The disease was pandemic more than half a
century ago but now is common in some parts in South and Southeast of the country.
Its control measures was launched since 1949 and a malaria eradication campaign
was initiated in 1951 (Berger 2019). Shortly, malaria was eradicated from majority
parts of the land. However, Southeastern Iran is still characterized by “refractory
malaria” affected by socioeconomic, geographical, climatic factors and vector diversity (Vatandoost et al. 2019; Hanafi-Bojd et al. 2011).
There are 31 anopheline species in Iran while 8 of these species are proved to be
malaria vectors (Azari-Hamidian 2007; Hanafi-Bojd et al. 2011). Herein, the malaria
vectors are composed of Anopheles stephensi, An. culicifacies, An. fluviatilis, An.
superpictus, An. d’thali, An. sacharovi, An. maculipennis and An. pulcherrimus. All
these species show endo/exophilic and endo/exophagic behaviour (Mehravaran et al.
2012; Schapira et al. 2018).
Vector control is the key strategy to reduce malaria transmission which is
primarily based on chemical control. Malaria vectors control in the country is
focused on Indoor residual spraying (IRS) using Lambda-cyhalothrin and
Deltamethrin, targeting larval breeding sites using Chlorpyrifos-methyl, application
of Bacillus thuringiensis israelensis, employment of larvivorous fish including
Aphanius dispar (Cyprinodontidae) and Gambusia affinis (Poeciliidae) and distributing long-lasting insecticidal nets (LLINs) (Hanafi-Bojd et al. 2010). IRS increases
the direct contact of humans and animals with insecticides (Gyalpo et al. 2012).
Among many disadvantages of chemical control is insecticide resistance in vectors
of malaria (Abbasi et al. 2019). Main malaria vectors of the country are resistant to
some of the pyrethroids (Vatandoost and Hanafi-Bojd 2012). Reviews on insecticide
resistance of Anopheles mosquitoes indicate An. stephensi is resistant to Dieldrin and
Malathion and tolerant to Deltamethrin, Bendiocarb and Fenthion (Mogaddam et al.
2016; Hanafi-Bojd et al. 2012). An. culicifacies act as the main vector in the areas
which are under pressure of IRS while the main vector of malaria in the country is
An. stephensi (Pakdad et al. 2017).
However, ineffective chemical control in addition to environmental and health
hazards of this strategy inspired scientists to find some applicable biological control
agents. More than two hundred pathogens and parasites and more than five hundred
predators have been listed as natural enemies of mosquitoe larvae and adults (Bay
et al. 1976). Biological control of malaria vectors continues to be a component of
Integrated Vector Management (IVM).
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H. H. Allahverdipour and K. Akbarzadeh
16.2.1 Malaria and West Nile Virus
Malaria is one of the oldest parasitic diseases of the country where it is recorded as
endemic (Vatandoost et al. 2019). The disease was pandemic more than half a
century ago but now is common in some parts in South and Southeast of the country.
Its control measures was launched since 1949 and a malaria eradication campaign
was initiated in 1951 (Berger 2019). Shortly, malaria was eradicated from majority
parts of the land. However, Southeastern Iran is still characterized by “refractory
malaria” affected by socioeconomic, geographical, climatic factors and vector diversity (Vatandoost et al. 2019; Hanafi-Bojd et al. 2011).
There are 31 anopheline species in Iran while 8 of these species are proved to be
malaria vectors (Azari-Hamidian 2007; Hanafi-Bojd et al. 2011). Herein, the malaria
vectors are composed of Anopheles stephensi, An. culicifacies, An. fluviatilis, An.
superpictus, An. d’thali, An. sacharovi, An. maculipennis and An. pulcherrimus. All
these species show endo/exophilic and endo/exophagic behaviour (Mehravaran et al.
2012; Schapira et al. 2018).
Vector control is the key strategy to reduce malaria transmission which is
primarily based on chemical control. Malaria vectors control in the country is
focused on Indoor residual spraying (IRS) using Lambda-cyhalothrin and
Deltamethrin, targeting larval breeding sites using Chlorpyrifos-methyl, application
of Bacillus thuringiensis israelensis, employment of larvivorous fish including
Aphanius dispar (Cyprinodontidae) and Gambusia affinis (Poeciliidae) and distributing long-lasting insecticidal nets (LLINs) (Hanafi-Bojd et al. 2010). IRS increases
the direct contact of humans and animals with insecticides (Gyalpo et al. 2012).
Among many disadvantages of chemical control is insecticide resistance in vectors
of malaria (Abbasi et al. 2019). Main malaria vectors of the country are resistant to
some of the pyrethroids (Vatandoost and Hanafi-Bojd 2012). Reviews on insecticide
resistance of Anopheles mosquitoes indicate An. stephensi is resistant to Dieldrin and
Malathion and tolerant to Deltamethrin, Bendiocarb and Fenthion (Mogaddam et al.
2016; Hanafi-Bojd et al. 2012). An. culicifacies act as the main vector in the areas
which are under pressure of IRS while the main vector of malaria in the country is
An. stephensi (Pakdad et al. 2017).
However, ineffective chemical control in addition to environmental and health
hazards of this strategy inspired scientists to find some applicable biological control
agents. More than two hundred pathogens and parasites and more than five hundred
predators have been listed as natural enemies of mosquitoe larvae and adults (Bay
et al. 1976). Biological control of malaria vectors continues to be a component of
Integrated Vector Management (IVM).
580
H. H. Allahverdipour and K. Akbarzadeh