PH136 Vector Control: Exam Paper on Vector Borne Diseases (PDF)

PH 136: ENVIRONMENTAL AND OCCUPATIONAL HEALTH VECTOR CONTROL Prof. Vivien Fe. F. Fadrilan-Camacho | February 6, 2025 VECTOR-BORNE DISEASES (VBDs) OUTLINE...

PH 136: ENVIRONMENTAL AND OCCUPATIONAL HEALTH VECTOR CONTROL Prof. Vivien Fe. F. Fadrilan-Camacho | February 6, 2025 VECTOR-BORNE DISEASES (VBDs) OUTLINE ​ Illnesses caused by parasites, viruses, or bacteria VECTOR CONTROL transmitted by a vector. A.​ Vector a.​ Types of Vectors ​ Philippines: B.​ Vector-borne Diseases ○​ Vector-borne diseases are high despite advancements a.​ Examples of Vector-borne diseases in technology, interventions, and availability of b.​ Key facts controls, vaccines, and prophylactic measures. c.​ Key Issues ○​ Although there is still evidence of improved mortality C.​ Factors that Influence Vector-borne Diseases and morbidity. a.​ Population Migration ​ Many of these are preventable through informed b.​ International Travel and Commerce c.​ Land Use Change protective measures. d.​ Microbial Adaptation and Resistance ○​ SOLUTION: Vector control e.​ Lack of Reliable PUblic Infrastructure Services f.​ Climate Change EXAMPLES OF VECTOR-BORNE DISEASES D.​ Vector Control ​ Philippines a.​ Examples, Disease caused, and Type of Pathogen E.​ Mosquitoes Ibay ○​ Mosquitoes: Chikungunya, Dengue, Japanese a.​ Stages of Development encephalitis, Lymphatic Filariasis, Malaria, Zika virus b.​ Malaria disease c.​ Dengue ○​ Snails: Schistosomiasis (areas in Visayas that are d.​ Vector Control Measures endemic) F.​ Mosquito Controls ​ Global a.​ Biological Control ○​ Mosquitoes: Yellow Fever, Rift Valley Fever, West Nile b.​ Chemical Control c.​ Environmental Control Fever d.​ Dengue Control ○​ Triatomine Bugs: Chagas Disease G.​ Vector Surveillance ○​ Ticks: Lyme Disease, Tick-borne Encephalitis, Typhus H.​ Environmental Management ○​ Sandflies: Leishmaniases a.​ Improvement of Water Supply and Water Storage ○​ Mites and lies: Rickettsialpox, Typhus Systems ○​ Flies: Onchocerciasis, Human African b.​ Solid Waste Management c.​ Opportunities for Prevention of Vector-borne Trypanosomiasis Disease in and Age of Change ○​ Fleas: Murine Typhus, Plaque d.​ Integrated Vector Control Management I.​ References J.​ Review Questions K.​ Appendix VECTOR CONTROL VECTORS ​ Carriers of disease agents from one organism to another ​ Facilitates the spread of the disease ​ Plays a big role in continuing the life cycle of a disease agent TYPES OF VECTORS ​ Mechanical Vectors ○​ Microorganisms attach themselves to appendages of the vector Figure 1. Examples of globally relevant VBDs [Fadrilan-Camacho, 2025]. ○​ The vector physically/mechanically facilitates the spread from one organism to another KEY FACTS (2020) ○​ Example: housefly carrying enteric organisms ​ Global ​ Enteric: refers to the GI tract ○​ Accounts for ~17% of global burden of communicable ​ Biological Vectors diseases, causing 700,000 deaths yearly. ○​ The vector is part of the life cycle of the ○​ Affects poorer populations living in degraded microorganism environments and unfavorable housing conditions. ○​ Has an action that will facilitate the entry from one ○​ > 3.9 billion people in over 128 countries are at risk of body to another (e.g., biting) contracting dengue, with ~ 96 million cases per year. ○​ Example: Anopheles mosquitoes for malaria ○​ Malaria causes > 400,000 deaths yearly, most are ​ The presence of vectors means that the transmission chain children under 5 years of age. will proceed and facilitate the transmission of infectious ○​ Other diseases (i.e., Chagas disease, leishmaniasis, agents schistosomiasis) affect hundreds of millions of people. ○​ ↑ Disease, Death, Discomfort ○​ All of these are preventable with strategic vector ○​ ↓ Productivity control and interventions. ​ If workers are impacted by disease it will have a socio-economic impact globally. #MagkabigkisBenteSais Team 02 | 1 of 9  MICROBIAL ADAPTATION AND RESISTANCE ​ Antibiotics use → drug resistance ​ Unrationalized use of antibiotics → Global problem ○​ Not limited to usage of humans, but also include inappropriate disposal → microbial adaptations and KEY ISSUES resistance. ​ Zoogeography describes the natural distribution of vector ○​ Even though it is indirect in various ways, it still species/species complexes. facilitates gradual worsening of adverse drug reactions ​ Climate is the major driver. (ADR). ​ Man-made drivers modulate the distribution and include ​ Currently, ADR is still ranked among the leading global climate change, hydrological changes (irrigation, causes of mortality in many countries, recognized dams), changed land use patterns, and urbanization. as one of the hazards of drug therapy. ​ Although antibiotics are relatively safe with FACTORS THAT INFLUENCE VECTOR-BORNE DISEASES rational use for treatment and/or prophylaxis for From the reading of Müller et. al. (2019) under section 4.1 various infectious diseases, with its ↑ prescription Triple Vulnerability: Climate Change, Biodiversity, and VBDs among all ages, it substantially contributes to (p. 71) reported ADR (Gomes et al. 2020). ​ VBDs are highly interconnected with climate change, and degree of biodiversity given that its epidemiological LACK OF RELIABLE PUBLIC INFRASTRUCTURE SERVICES dynamics involve complex interactions between the ​ Lack of funds for sanitation facilities, effective water vectors, pathogen, and host (Engering et al. 2013). management systems, and basic public health care. ​ Aside from temperature and rainfall changes, heterogeneity ​ “Cleanliness is next to godliness” of landscapes (Chavez et al. 2011), urbanization (Woo et al. 2017), and ○​ Implies that people have the moral obligation to keep forest degradation (Brownstein et al. 2005) are some of the extrinsic themselves and their homes clean. factors that determine both VBDs’ risk and burden. ○​ “Cleanliness of the body, mind, soul.” ​ Includes the unavailability of public health programs and POPULATION MIGRATION services, especially in far-flung areas. ​ War, environmental degradation, and regional conflicts ○​ Absence of vector control for Dengue and Malaria in may drive people away from their residences. far-flung areas despite these programs and services ​ Rapid unchecked urbanization are needed most. ○​ Vectors get access to habitats like sewers, water storage containers, stagnant water, etc. CLIMATE CHANGE ○​ ↑ job opportunities in the urban, ↑ people come to ​ Global climate change → increases disease associated urban areas → access to habitats mosquitoes due to warmer climates and increased rainfall ○​ ↑ number of people in urban areas, ↑ sites that can ○​ Dengue became an all year-round problem as serve as habitats and/or breeding grounds for vectors. opposed to it previously only a problem during the ​ ↑ population density → development of preferential feeding summer (cases ↑ during warmer climates). solely on humans by vectors ○​ ↑ in temperature and rainfall → vectors develop ○​ Chain of events that start with environmental adaptive behaviors. degradation (loss of habitats, loss of nourishment ​ Change in breeding sites, feeding patterns. sources) → forces vectors to rely on humans VECTOR CONTROL INTERNATIONAL TRAVEL AND COMMERCE ​ Vector control is affected by: ​ Facilitates continuous spread of disease vectors ○​ Advanced technology ​ Seaports, airports, and cemeteries are especially ○​ Modern pesticides vulnerable. ○​ Man’s ability to modify environmental conditions ​ Also includes the effects of global trade in food resulting ​ Vector control in unhygienic food production, handling, and preparation. ○​ Ecology and biology ○​ Cataracts pests and animals that are potential vectors ○​ Surveillance ​ Patterns of breeding, patterns of surviving LAND USE CHANGE ○​ Control measures ​ Space is a problem especially in the urban area. ○​ One reason is industrialization where rural areas EXAMPLES become more industrialized → disruption of natural Table 1. Vectors and Their Diseases habitats. Type of Vector Disease Caused ​ Changes in land and water use patterns Pathogen ​ Conflict between boosting the economy through industries Chikungunya Virus against sole reliance on agriculture. Dengue Virus ○​ Construction of commercial buildings, malls, etc. M ​ Mass deforestations alter natural habitats O Lymphatic Filariasis Parasite ​ Poor water management practices → more habitats and S Aedes Q Rift Valley Fever Virus breeding sites for vectors: U ○​ Dam building Yellow Fever Virus I ○​ Open irrigation canals T Zika Virus ○​ Flooded rice fields O​ ○​ Open sewer pits E Lymphatic Filariasis Parasite S Anopheles Malaria Parasite PH 136 | Vector Control 2 of 9  Japanese encephalitis Virus STAGES OF DEVELOPMENT ​ 4 stages of development: Culex Lymphatic Filariasis Parasite ○​ Egg West Nile Fever Virus ○​ Larva ○​ Pupa Aquatic Snails Schistosomiasis (bilharziasis) Parasite ○​ Adult Blackflies Onchocerciasis (river blindness) Parasite ​ Fertilized eggs require water for hatching ○​ Water is the breeding sites of mosquitoes, as well as Plaque (rats to humans) Parasite Fleas where they hatch and grow Tungiasis Ectoparasite ​ Important part of a mosquitoes’ life ○​ Can be the basis for vector control measures (e.g. Typhus Bacteria Lice Dengue with the 4 O’clock habit) Louse-borne Relapsing Fever Bacteria ​ Anopheles larvae lie parallel to the water surface ​ Culicine larvae hang at 45° angle to the surface Leishmaniasis Parasite ​ Female mosquito - vector of diseases (e.g. malaria, Sandflies Sandfly Fever (Phlebotomus Virus dengue) Fever) ○​ A biting mosquito, hence takes a blood meal Crimean-Congo Haemorrhagic Virus ○​ Why do only female mosquitoes bite? Fever ​ Females require blood for reproduction since they Lyme Disease Bacteria need protein from the blood for ovulation and egg Relapsing Fever (borreliosis) Bacteria laying [BYJU’s, n.d.] Ticks Rickettsial Diseases (spotted Bacteria fever, Q fever) Tick-borne Encephalitis Virus Tularaemia Bacteria Triatomine Chagas Disease (American Parasite Bugs trypanosomiasis) Sleeping Sickness (African Tsetse Flies Parasite trypanosomiasis) MOSQUITOES From Müller et. al. (2019) under section 4.2.1 Influence of Temperature on Vector Mosquitoes and Associated Pathogens (p. 72) ​ In holometabolous vector mosquitoes, larval rearing temperature influences: ○​ Development times Figure 2. Malaria Cases and Deaths in the Philippines ○​ Larval survival ○​ Adult longevity ​ Decreasing trend in morbidity and mortality caused by ○​ Length of female gonotrophic cycle malaria in the country throughout the years ○​ Adult body size ○​ Has more cases than deaths ​ In arboviruses, temperature effects plaque growth and replication speed ​ Mosquito-arbovirus interactions such as virus susceptibility, prevalence of dissemination, transmission rate and extrinsic incubation period are influenced by temperature ​ Temperature plays a key role in determining the viral transmission areas ○​ Knowledge on temperature effects triggering vector mosquitoes' mortality and development is important to explain disease outbreaks From Müller et. al. (2019) under section 4.2.2 Distributional Changes of Mosquito Vector Species (pp. 72-73) ​ Climate change will not uniformly increase the burden of VBDs, but changes will differ between regions ​ Human transport activities and temperature change facilitate the establishment of vector species and Figure 3. New Article Indicating that All Provinces Except Palawan is Malaria-Free highlight the importance of actively preventing such establishments ​ DOH is aiming for a malaria-free Philippines by 2030 ​ Despite temperature, climate change will lead to ○​ DOH is coordinating with other organizations and hydrological changes. agencies to become successful in achieving this goal ​ Climate and photoperiod also alter the host-seeking and ​ As of 2023, among the 81 provinces in the country, feeding activity in ticks as well as the seasonal Palawan is the only province that isn’t malaria free occurrence of vector stages ○​ Significant progress in malaria control in the Philippines PH 136 | Vector Control 3 of 9 ​ Incidence of malaria nationwide declined by 87% from 48,569 in 2003 to only 6,120 cases in 2020 ​ Why is it taking so long to be a malaria-free country? ○​ By nature, tropical countries are preferred by vectors as breeding sites, which is why eliminating them entirely is very challenging Figure 5. Reported Dengue Cases by Morbidity Week ​ A 41% decrease compared to the same period in 2022 ​ As of December 2, 2023, the number of cases is 23% lower compared to the same period in 2022 ​ But although dengue is common during the rainy season, Figure 4. Life Cycle of the Malaria Parasite we still have dengue cases outside the rainy season ○​ Throughout the months, the cases did not vary ​ Anopheline mosquito is part of the lifecycle of the significantly, but of course, the peak is during the rainy Plasmodium parasite season ○​ Plasmodium - parasite or infectious agent causing ○​ Reason is due to climate change malaria ​ Undergoes growth in the mosquito before it VECTOR CONTROL MEASURES transfers to humans through bites ​ Effective vaccines or drugs are not always available, thus ​ Note: Life cycle of the malaria parasite will NOT be we must control the transmission included in PH 136 examinations. ○​ Control of vector is considered ​ Early control programs included the screening of houses, MALARIA the use of mosquito nets, the drainage or filling of swamps ​ Caused by Plasmodium spp. and other water systems/containers ​ Carried by Anopheles minimus flavirostris ​ Vector control will depend on the following: ○​ A biological vector ○​ Local ecology and behavior of the vector species, ○​ Part of the life cycle of the plasmodium species including its habitats, flight range, feeding preferences (disease agent causing malaria) and seasons ​ Fever is the most common symptom for malaria ○​ Local epidemiology of the disease e.g. endemic in the area or not PLASMODIUM ○​ Human activity e.g. irrigation and animal farming Plasmodium Plasmodium Plasmodium Plasmodium ○​ Socioeconomic conditions of affected communities vivax* falciparum* malariae ovale ○​ Cultural context In tropical and Widest Widely Rare specie in ○​ Feasibility of applying interventions in specific settings subtropical distribution distributed Africa, Asia acceptable to the population e.g. indigenous people regions Quartan might not be as open/welcoming in using chemicals Fever every 48 Also with 48 ○​ Environmental/climate change malaria (every 48 hour cycle hours hour cycle 72 hours) ​ 1940’s - discovery of the dichlorodiphenyltrichloroethane Relapses are Relapses are Persistent (DDT) common rare infection ○​ Major breakthrough in vector control *Most common in the Philippines are Plasmodium vivax and ○​ Although it was found to be effective in killing pests, it Plasmodium falciparum also kills other animals (e.g. fishes and birds) ○​ Regarded as a miracle chemical; led to its DENGUE irresponsible use even at home and directly to humans ​ Caused by arbovirus for pediculosis (louse/kuto) ​ Carried by Aedes aegypti ○​ DDT was banned due to its toxic effects to the ○​ A day-biting mosquito environment and to human and public health ○​ Lays eggs in clear, stagnant water ○​ Environmental movements emerged for environmental ○​ Can be distinguished from other types of mosquitoes protection because of DDT by the white stripes on its body ○​ Limitations of DDT: ○​ Bites during the early morning and late afternoon ​ Cost hours ​ Resistance ○​ Rests indoors in dark places or outside where it is ​ Side effects cool and shaded ​ Measures to reduce population densities ​ Control is done by the control of the mosquito vector ○​ Source reduction ​ Different forms of environmental management (engineering, modification, manipulation) PH 136 | Vector Control 4 of 9  ​ Predator-prey systems (fish, predator insects, DENGUE CONTROL amphibians) DOH 4S Strategy Against Dengue ​ Microbial toxins 1.​ Search and destroy breeding places ○​ Chemical larviciding 2.​ Self-protection measures ○​ Chemical adulticiding 3.​ Seek early consultation ​ e.g. fogging 4.​ Say “NO” to indiscriminate fogging ​ Measures to reduce vector longevity/vectorial capacity ○​ Fogging has benefits but we don't want it to be used ○​ Indoor residual spraying haphazardly without any justified reasons ​ Personal/community protection ○​ It has potential exposure effects on the community ○​ Insecticide treated nets and materials ○​ Fogging is useful during outbreaks (high mosquito ○​ Housing improvement indices) but has limitations: ○​ Zooprophylaxis ​ Drives away adult mosquitoes from one place to ​ In the pipeline another ○​ Genetically engineered mosquitoes ​ No effect on larvae ​ Only a temporary solution MOSQUITO CONTROLS ○​ Fogging as a lone intervention WILL NOT solve the CHEMICAL CONTROL problem of dengue ​ Insecticides ​ Dengue mosquitoes feed both indoors and outdoors ○​ Adulticides - targets adults during the daytime (during early morning hours and early ○​ Larvicides - targets larvae evening hours) and thrive in areas with standing clean ​ Stomach and contact poisons - for rat control water including water tanks, containers, and old tires ○​ e.g. fumigants for fumigation and fogging ​ Lack of regular water supply and garbage collection ​ DDT (dichlorodiphenyltrichloroethane) contribute to increased breeding ​ Organophosphates - for the protection of man and the ​ The DOH is directing all health facilities to take part in environment, banned due to its toxic effects to human search and destroy activities after every flag ceremony and health and the environment conduct Sabayang 4 O’clock Habit para Deng-Get out activity every Friday, including: Factors Affecting Level of Pesticides in Food Chains ○​ Cleaning and draining containers of stagnant water 1.​ Amount of pesticide ingested ○​ Ensuring canals and streams are flowing ○​ Ingested by the animal/vector 2.​ Time period over which pesticides are ingested On additional information: 3.​ Pesticide-storage capability of animal ​ See Appendix A. Relationship between Sustainable 4.​ Rate of detoxification and excretion Development Goals and control of VBDs (WHO, 2017). ○​ Metabolic nature VECTOR SURVEILLANCE BIOLOGICAL CONTROL ​ Dengue vector surveillance employs several ​ Pinaka mahirap gawin, less used type of control entomological indicators that have been developed to ○​ Dealing with another living organism makes it difficult assess the risk of outbreaks occurring to control, there are a lot of factors to consider ○​ House index (HI) - the percentage of houses infested ​ Examples: with larvae and/or pupae ○​ Small fishes feed on larvae ○​ Container index (CI) - the percentage of ○​ Birds, bats, and dragonflies eat adult mosquitoes water-holding containers infested with larvae or pupae. Disadvantages to Humans ○​ Breteau index (BI) - number of positive containers per ​ Parasitic infestations 100 houses inspected ​ Exposure to harmful toxins ○​ Ovitrap index ​ Allergic reactions ​ Conducted by agencies such as the Department of Health (DOH) and other organizations Disadvantages to Environment ​ Entomological indicators can provide information or data ​ Infestation/predation on beneficial organisms on the extent of the problem and risk of outbreaks ​ Displacement of beneficial organisms occurring ​ Interference with control program ENVIRONMENTAL MANAGEMENT ENVIRONMENTAL CONTROL ​ Seeks to change the environment to prevent/minimize ​ Most-used control, more practical vector propagation and human contact with the ​ Appropriate for low resource countries or environments vector-pathogen ​ 2 sources of mosquito breeding sites: ○​ by destroying, altering, removing or recycling ○​ Man-made non-essential containers that provide larval habitats. ​ Ditches that do not drain ​ should be the mainstay of dengue vector control ​ Standing water from poor irrigation practices ​ Anything that can collect water TYPES OF ENVIRONMENTAL MANAGEMENT ○​ Natural water-holding areas 1.​ Environmental modification ​ Environmental modification (more long-lasting) ○​ long-lasting physical transformations to reduce ○​ e.g. filling, draining, coverage, reclamation or landfill vector larval habitats ○​ ie. installation of a reliable piped water supply to communities, including household connections 2.​ Environmental manipulation PH 136 | Vector Control 5 of 9  ○​temporary changes to vector habitats involving the ​ Rationale: management of “essential” containers ○​ Driving forces behind a growing interest in IVM include ○​ ie. Frequent emptying and cleaning by scrubbing of the need to overcome challenges experienced with water-storage vessels, flower vases, and desert room conventional single-intervention approaches to coolers, Cleaning of gutters, sheltering stored tires vector control as well as recent opportunities for from rainfall, recycling/proper disposal of discarded promoting multi-sectoral approaches to human health containers & tires, Management or removal from the vicinity of homes of plants such as ornamental or wild From the reading of Müller et. al. (2019) under section 4.4.4 bromeliads that collect water in the leaf axils Sustainable Control Programs 3.​ Changes to human habitation or behaviour ​ IVM makes use of vector surveillance, risk mapping ○​ actions to reduce human-vector contact and a variety of vector prevention and control tools, and ○​ ie. installing mosquito screening on windows, doors adjusts the set of applied tools to local conditions in a and other entry points, mosquito nets while sleeping time- and dose-dependent manner. during daytime ​ IVM have brought only few benefits in the attempt to IMPROVEMENT OF WATER SUPPLY AND WATER STORAGE control the vector populations SYSTEMS ○​ will require the engagement & collaboration of local communities ​ Fundamental method of controlling Aedes vectors, especially Aedes aegypti 5 Key Elements of Global Strategic Framework for IVM: ​ Water piped to households is preferable ○​ Compared to water drawn from wells, communal 1.​ Advocacy, social mobilization, regulatory control for standpipes, rooftop catchments, and other public health and empowerment of communities water-storage systems 2.​ Collaboration within the health sector and with other ​ Potable water must be supplied reliably so that sectors through the optimal use of resources, planning, water-storage containers that serve as larval habitats monitoring and decision-making. ○​ Drums, overhead or ground tanks, concrete jars – are 3.​ Integration of non-chemical and chemical vector control not necessary methods, and integration with other disease control ​ Urban Areas: use of cost-recovery mechanisms measures ○​ introduction of metered water 4.​ Evidence-based decision making guided by operational ​ encourage household collection research and entomological and epidemiological ○​ storage of roof catchment rainwater that can be surveillance and evaluation harvested at no cost, 5.​ Development of adequate human resources, training and ​ continued use of storage containers career structures at national and local level to promote capacity building and manage IVM programmes SOLID WASTE MANAGEMENT REFERENCES ​ In the Context of dengue vector control: ​ Lectures ○​ “Solid waste” = non-biodegradable items of Fadrilan-Camacho, VFF. (2025). Vector Control [Slides]. ​ household, community and industrial waste ​ https://upm.instructure.com/courses/26392/files/​ ​ benefits of reducing the amount of solid waste in urban ​ 1867104?module_item_id=445486. ​ Book Chapter environments Müller, R., Reuss, F., Kendrovski, V., & Montag, D. (2019). ​ ○​ extend beyond those of vector control, and applying ​ Vector-Borne Diseases. In Biodiversity and Health in the ​ ​ Face of Climate Change (pp. 67–90). Springer, Cham. ​ many of the basic principles ​ https://doi.org/10.1007/978-3-030-02318-8_4 ○​ contributes substantially to reducing the availability of Ae. aegypti larval habitats. REVIEW QUESTIONS ​ Basic Rule: “reduce, reuse, recycle” 1.​ True or False: The presence of vectors is directly ○​ highly applicable proportional to human productivity. ​ Efforts to reduce solid waste 2.​ True or False: Effective vaccines or drugs are not ○​ directed against discarded or non-essential always available to control transmission. containers, particularly if they have been identified in 3.​ True or False: Improvement of Water Supply and Water the community as important mosquito-producing Storage System is a fundamental method of controlling containers Anopheles vectors. OPPORTUNITIES FOR PREVENTION OF VECTOR-BORNE 4.​ The following are limitations to DISEASE IN AND AGE OF CHANGE Dichlorodiphenyltrichloroethane (DDT) EXCEPT: ​ Early detection of pathogen introduction due to travel & a.​ Cost commerce b.​ Environmental Impact ​ Develop and disseminate vector control strategies & c.​ Resistance vaccines d.​ Side effects ​ Improve water supply and sanitation 5.​ The House index (HI) is the percentage of houses ​ Assure public health services: infested with larvae and/or pupae. The Container Index ○​ Family planning (CI) is the number of positive containers per 100 ○​ Immunization houses inspected. ○​ Health education a.​ Both statements are correct. b.​ First statement is incorrect, but the second statement INTEGRATED VECTOR CONTROL MANAGEMENT is correct ​ A rational decision-making process c.​ First statement is correct, but the second statement is ○​ optimal use of resources for vector control incorrect ​ Seeks to improve: efficacy, cost-effectiveness, ecological d.​ Both statements are incorrect soundness, and sustainability of disease-vector control PH 136 | Vector Control 6 of 9 6.​ Which of the following is not a vector control measure? a.​ Measures to reduce vector longevity b.​ Personal/community protection c.​ In the Pipeline d.​ Measures to reduce population densities e.​ None of the above 7.​ The following are included in the 4S Strategy Against Dengue EXCEPT: a.​ Search and Destroy Breeding Places b.​ Self-protection measures c.​ Seek consultations only when symptoms are severe d.​ Say No to indiscriminate fogging 8.​ Which of the following statements is NOT true regarding vector-borne diseases? a.​ More job opportunities in urban areas can increase access of vectors to habitats, which, in turn, can increase vector-borne disease b.​ Changes in temperature and rainfall due to climate change may drive vectors to develop adaptive behavior.s c.​ The construction of buildings and malls may be effective in protecting humans from vector-borne diseases. d.​ Unrationalized use of antibiotics may cause microbial adaptation and resistance, which helps in the proliferation of vector-borne diseases. 9.​ In solid waste management, the basic rule of “reduce, reuse, recycle” is not applicable. The benefits of reducing the amount of solid waste in urban environments extend beyond those of vector control, and applying many of the basic principles can contribute substantially to reducing the availability of Ae. aegypti larval habitats. a.​ Both statements are correct. b.​ First statement is incorrect, but the second statement is correct c.​ First statement is correct, but the second statement is incorrect d.​ Both statements are incorrect 10.​ The __________ seeks to improve the efficacy, cost-effectiveness, ecological soundness,s and sustainability of disease-vector control. PH 136 | Vector Control 7 of 9  APPENDICES Appendix A. Relationship between Sustainable Development Goals and control of VBDs (WHO, 2017). Adapted from WHO (2017). The Global vector control response (GVR) 2017-2030. SDG Relationship to VBDs Examples Goal 3. Ensure healthy lives VBDs are a major contributor to global ​ VBDs account for > 17% of global burden of and promote well-being for morbidity and mortality. infectious diseases all at all ages. ○​ 80% of global population is at risk from 1 VBD ○​ > 50% at risk of 2 or more VBDs. Goal 6. Ensure access to Investment in clean water and sanitation ​ Open stored water containers are a major habitat for water and sanitation for all. can reduce the risk from VBDs, immature dengue, chikungunya, and Zika virus vectors worldwide. ○​ Provision of piped water and/or mosquito-proof water storage containers can reduce the transmission. Goal 11. Make cities Ending VBDs makes cities (and slums) safer. Resilience against VBDs needs to be included in strategic inclusive, safe, resilient, and planning for urban development. sustainable. Goal 13. Take urgent action Mitigating the impacts of climate change ​ VBDs are highly sensitive to climatic conditions, to combat climate change has the potential to reduce VBDs. especially temperature, rainfall, and relative humidity. and its impacts. ○​ Patterns of epidemiology change more rapidly than health policy can respond. ○​ Climate change can impact all VBDs. Goal 15. Sustainaby Maintaining terrestrial ecosystems and ​ Bio-reserves can harbour vector populations in manage forests, combat halting biodiversity loss will help reduce protected areas. desertification, halt and VBDs in some places, but ↑ in others. ​ Biodiversity loss (deforestation) may enhance the reverse land degradation, risk of some diseases like malaria, while biodiversity halt biodiversity loss. gains (reforestations) could sometimes increase the risk for the other diseases. Significantly reduce the impact of invasive Invasive vector species (Aedes albopictus) species on land and water ecosystems. Promote fair and equitable sharing of benefits Biological vector control arising from the utilization of genetic resources and promote appropriate access to such resources. Appendix B. Relationship between Sustainable Development Goals and control of VBDs (WHO, 2017). Vector Disease Caused Type of Pathogen Chikungunya Virus Dengue Virus Lymphatic Filariasis Parasite M Aedes O Rift Valley Fever Virus S Q Yellow Fever Virus U Zika Virus I T Lymphatic Filariasis Parasite O​ Anopheles E Malaria Parasite S Japanese encephalitis Virus Culex Lymphatic Filariasis Parasite West Nile Fever Virus Aquatic Snails Schistosomiasis (bilharziasis) Parasite Blackflies Onchocerciasis (river blindness) Parasite Plaque (rats to humans) Parasite Fleas Tungiasis Ectoparasite Typhus Bacteria Lice Louse-borne Relapsing Fever Bacteria Leishmaniasis Parasite Sandflies Sandfly Fever (Phlebotomus Fever) Virus Crimean-Congo Haemorrhagic Fever Virus Ticks Lyme Disease Bacteria PH 136 | Vector Control 8 of 9  Relapsing Fever (borreliosis) Bacteria Rickettsial Diseases (spotted fever, Q fever) Bacteria Tick-borne Encephalitis Virus Tularaemia Bacteria Triatomine Bugs Chagas Disease (American trypanosomiasis) Parasite Tsetse Flies Sleeping Sickness (African trypanosomiasis) Parasite Figure 1. Examples of globally relevant VBDs (Fadrilan-Camacho, 2025). Figure 4. Life Cycle of the Malaria Parasite. PH 136 | Vector Control 9 of 9