Increased human risk from communicable disease events (outbreaks) after disasters.

Written By: Website Administrator

31/03/2014

Natural disasters such as floods, hurricanes and droughts occur globally every year because of adverse weather conditions or poor land use. Climate change, together with population growth and urbanization as well as travel will increase the number of disasters and change the disease pattern and frequency of disease outbreaks.

Most natural disasters result in major communicable disease outbreaks and deaths. These communicable diseases such as dengue fever, typhoid fever leptospirosis are endemic to Fiji while more recent threats occur from emerging communicable diseases such as Zica Virus (Cook Islands, French Polynesia), Chikungunya (New Caledonia, PNG). An understanding of environmental and host factors, transmission pattern and other characteristics of the infectious agent (virus, bacteria) is essential to the control and prevention of these diseases. However Fiji, an understanding of the risk behaviours is also critical to reduce the incidence and devastating mortality associated with these diseases.

The term outbreak is used interchangeably with the similar but more technical term ‘epidemic’. However, the latter is preferred as it appears to cause less panic or anxiety. An outbreak or epidemic is defined as the occurrence of cases of an illness with a frequency that is clearly in excess of what is expected in a given area, therefore, demanding emergency control measures. The Republic of Fiji is currently experiencing a national outbreak or epidemic of dengue fever. Dengue fever infections in Fiji occur throughout the year (endemic) but what is unique in this situation, Dengue serotype 3 (DEN3) is an uncommon type of dengue that has not been detected in the region for many years. The outbreak of dengue fever in Fiji outbreak was initialized described as a localized event in Suva and central division but now the incidence of disease has expanded to other parts of the country.

There are a few reasons for the increase in incidence and risk of communicable disease outbreaks in Fiji. Firstly, our location as the hub of trade and travel in the South Pacific increases the populations’ vulnerability and risk to new and emerging communicable diseases. Humans that travel are common hosts to spreading these diseases across borders, often unaware of incubating the agent (virus) because they do not display or experiencing any symptoms or signs of disease until reaching their destination.  Secondly, trade brings into the country a lot of air and sea traffic that potentially carries breeding places for mosquitoes from a foreign country. In addition, the other important factor is related to a changing environment commonly referred to as an impact climate change or extreme weather condition that precipitate frequent occurrence of natural disasters. There is sufficient evidence to show that climatic conditions increase the risk of communicable disease events such as outbreaks in the region. During natural disasters, Pacific island countries are commonly affected because of unprotected exposures to the elements, poor housing structures, lack of proper utilities related to poverty or access and an element of inadequate disaster preparedness efforts due possibly either to ignorance or laissez-faire attitude.

The impact of communicable diseases may occur immediately after the disaster but most generally occur weeks after the event due to displacement, disruption of utilities and access to health services, and limited choice in food supply and limited access to basic needs. Communicable diseases that commonly increase after floods in Fiji are diarrhoeal diseases, leptospirosis, dengue fever and typhoid fever. The most common diseases with the highest recorded fatalities are leptospirosis, which presents similar and often mistaken for the severe haemorrhagictypre of Dengue fever. In figure 1, there was a significant increase in cases of Leptospirosis at flood prone areas in Fiji, at least 5-8 weeks after a flooding event. There were approximately 300 cases with 25 deaths following floods in 2012. One of the high risk behaviours associated with this disease in Fiji and commonly seen live television, is wading through infected waters. Unknown to the individual is that animal urine in flooded waters in a very small dose entering through the cornea of the eye is sufficient to cause an infection.

 

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Figure 1 leptospirosis after sequential flooding disasters, Western division 2012

 

Dengue fever on the other hand is not directly associated with flood because all the containers are washed away (but not destroyed). A dengue fever outbreak may occur when mosquitoes begin breeding again in ideal conditions (man-made containers) after a flood which usually is at least 6 weeks after a flooding event. Transmission of the virus by young mosquitoes can be further exacerbated by disruption of basic water supply and poor sanitation. There are certain risk behaviours such as increased exposure to mosquitoes while socializing outside, wearing minimal clothing due to humidity, movement of infected persons to another area and changes to the environment.

The risk of disease outbreaks and deaths during natural disasters and public health emergencies may be further minimized through early introduction of disease surveillance for early detection of outbreaks, epidemic preparedness, effective prevention and control including case management. Early detection, reporting and response are vital to limit the spread of outbreaks and epidemics. Failure to implement timely, effective and coordinated measures could also result in the occurrence of other chronic diseases:

  • Re-emergence of old disease threats e.g. TB;
  • Outbreaks of changed disease patterns e.g. Typhoid fever;
  • Outbreaks due to changed vulnerability such as heavy urbanization with more informal housing sectors;
  • Further spread of neglected diseases e.g. Leprosy, etc.
  • High morbidity and mortality from delayed epidemic detection and response e.g. dysentery, meningitis.
  • Emergence of a few ‘super bugs’ which are resistant to all antibiotics. They were limited to hospitals previously, but are now circulating in communities.

 

It never ends with the list of communicable diseases that increase after natural disasters and extreme weather conditions which benefit the proliferation of the vectors (mosquitoes) due largely to the risk bhaviours of humans.

The greatest challenge with these diseases after a natural disaster is the common clinical presentation that is indistinct from others. Although caused by different agents, they often require a different treatment regime for infected individuals. For example; Dengue fever is similar in presentation to Leptospirosis but is a virus infection with no specific treatment while the latter is only effectively treated with antibiotics early in the disease course. It is often uncommon to have patients presenting to the clinic with one disease and sent home to return with another, especially when there are no diagnostic laboratory tests with 100% accuracy to detect either disease. Commonly, a subjective decision is made based on severity of presentation. This emphasizes the importance of prevention at the individual level on avoidance of floodwaters and reduction of man-made containers that breed mosquitoes. The individual level motivation must occur before any successful engagement of the community. Mass communication done proactively has an important in educating the public to adopt protective behavior and in reducing the risks to the individual, family and community.

Fact Sheet – Drought and Health

Category: Health Articles

Date: 08/09/14

Written By: Web Administrator

Drought is a natural phenomenon in which rainfall is lower than average for an extended period of time, resulting in inadequate water supply. Drought is generally categorized as a hydro-meteorological hazard even though there are terms of other typologies of droughts as such as meteorological drought, agricultural drought, hydrological drought, and socio-economic drought. A drought as a hazard does not automatically lead to disaster. Only when people who are unable to cope with its effects; it becomes a disaster. Drought can therefore lead to public health problems.

Overview

In Fiji almost all droughts have been associated with the El Nino phenomena. The El Nino years in the past century include; 1902, 1905, 1911-1915, 1918, 1923, 1925-1926, 1930, 1932, 1939-1941, 1951, 1957, 1965, 1969, 1972, 1976, 1982, 1987, 1991-1995, 1997 and 2002.

The September 1997 – 1998 drought reached a level, which had warranted the declaration of a national emergency and this was noted to be the worst drought to affect Fiji for the century. It is estimated that approximately 48,000 households (about 220,000 people) were affected directly in various parts of the country.

Drought can affect areas or communities differently depending on several additional variables. These variables include:

  • the structure and capacity of existing water systems,
  • local governance of water use,
  • economic development,
  • the at-risk populations living within the affected area, and
  • other societal factors, such as the presence of local social networks

 

Public Health Implications

The possible public health implications of drought include:

  • Compromised quantity and quality of drinking water;
  • Increased recreational risks;
  • Effects on air quality;
  • Diminished living conditions related to energy, air quality, and sanitation and hygiene;
  • Compromised food and nutrition; and
  • Increased incidence of illness and disease.

The health implications of drought are numerous and far reaching. Some drought-related health effects are experienced in the short-term and can be directly observed and measured. However, the slow rise or chronic nature of drought can result in longer term, indirect health implications that are not always easy to anticipate or monitor.

 

Health Implications of Drought

Drought poses many and far reaching health implications. Some drought-related health effects occur in the short-term and can be directly observed and measured. But the slow rise or chronic nature of drought also can result in longer term, indirect health implications that are not always easy to anticipate or monitor.

 

Health Implications of Drought: Water

Reduced stream and river flows can increase the concentration of pollutants in water and cause stagnation. Higher water temperatures in lakes and reservoirs lead to reduced oxygen levels. These levels can affect fish and other aquatic life and water quality.

Runoff from drought-related wildfires can carry extra sediment, ash, charcoal, and woody debris to surface waters, killing fish and other aquatic life by decreasing oxygen levels in the water. Many parts of Fiji depend on groundwater as a primary source of water. Over time, reduced precipitation and increased evaporation of surface water mean that groundwater supplies are not replenished at a typical rate.

 

Health Implications of Drought: Food and Nutrition

Drought can limit the growing season and create conditions that encourage insect and disease infestation in certain crops. Low crop yields can result in rising food prices and shortages, potentially leading to malnutrition.

Special emphasis on responding to the nutrition needs of infants and young children, as well as pregnant and lactating women must be a priority; and that responses during a drought must be designed to achieve longer-term nutrition needs.

Drought can also affect the health of livestock raised for food. During drought, livestock can become malnourished, diseased, and die.

Health Implications of Drought: Air Quality

The dusty, dry conditions and wildfires that often accompany drought can harm health. Fire and dry soil and vegetation increase the number of particulates that are suspended in the air, such as pollen, smoke, and fluorocarbons. These substances can irritate the bronchial passages and lungs, making chronic respiratory illnesses like asthma worse. This can also increase the risk for acute respiratory infections like bronchitis and bacterial pneumonia.

Other drought-related factors affect air quality, including the presence of airborne toxins originating from freshwater blooms of cyanobacteria. These toxins can become airborne and have been associated with lung irritation, which can lead to adverse health effects in certain populations.

Health Implications of Drought: Sanitation and Hygiene

Having water available for cleaning, sanitation, and hygiene reduces or controls many diseases. Drought conditions create the need to conserve water, but these conservation efforts should not get in the way of proper sanitation and hygiene.

Personal hygiene, cleaning, hand washing, and washing of fruits and vegetables can be done in a way that conserves water and also reduces health risks. Installing low-flow faucet aerators in businesses and homes is one example of how to reduce water consumption while maintaining hand washing and other healthy hygienic behaviours.

Health Implications of Drought: Recreational Risk

People who engage in water-related recreational activities during drought may be at increased risk for waterborne disease caused by bacteria, protozoa, and other contaminants such as chemicals and heavy metals. Exposure can occur through accidentally or intentionally swallowing water, direct contact of contaminants with mucous membranes, or breathing in contaminants.

Untreated surface water can be a health threat in drought conditions. In untreated surface waters, some pathogens, such as a type of amoeba (Naegleriafowleri), are more common during drought because low water levels may create warmer water temperatures that encourage their growth.

As the levels of surface waters used for boating, swimming, and fishing drop, the likelihood of injury increases. Low water levels in lakes can put people at risk for life-threatening injuries resulting from diving into shallow waters or striking objects that may not be immediately visible while boating. Low surface water levels can also expose potentially dangerous debris from the bottom of lakes, rivers, and ponds.

Health Implications of Drought: Infectious Disease

Increases in infectious disease can be a direct consequence of drought.

  • Viruses, protozoa, and bacteria can pollute both groundwater and surface water when rainfall decreases. People who get their drinking water from private wells may be at higher risk for drought-related infectious disease. Other groups also at increased risk include those who have underlying chronic conditions.
  • Acute respiratory and gastrointestinal illnesses are more easily spread from person to person when hand washing is compromised by a perceived or real lack of available water. During water shortages, the risk for infectious disease increases when hygiene is not maintained.
  • E. coli and Salmonella are examples of bacteria that during drought can more readily contaminate food and cause infectious disease. Food can serve as a vehicle for disease transmission during a drought because water shortages can cause farmers to use recycled water to irrigate their fields and process the food they grow. When used to grow crops, improperly treated water can cause a host of infectious diseases (such as those caused by toxin-producing E. coli and Salmonella), which can be life-threatening for people in high-risk groups. In addition, the likelihood of surface runoff, which can occur when rain fails to penetrate the dry and compacted soil that often accompanies drought, can cause the inadvertent contamination of crops.
  • Other infectious disease threats arise when drought leads to the contamination of surface waters and other types of water that are used for recreational purposes. When temperatures rise and rainfall declines, people are more likely to participate in water-related recreation. Persons exposed to contaminated recreational waters are more likely to become infected with pathogens that thrive in the shallow warm waters that exist during drought conditions.

Health Implications of Drought: Chronic Disease

Conditions associated with drought may negatively impact people who have certain chronic health conditions such as asthma and some immune disorders.

Drought-related changes in air quality, such as increased concentrations of air particulates and airborne toxins resulting from freshwater algal blooms, can irritate the eyes, lungs, and respiratory systems of persons with chronic respiratory conditions.

Changes in water quality, such as increased concentrations of contaminants, can threaten persons whose immune systems are compromised.

Health Implications of Drought: Diseases Transmitted by Insects and Animals

In periods of limited rainfall, both human and animal behaviour can change in ways that increase the likelihood of other vector borne diseases. For instance, during dry periods, wild animals are more likely to seek water in areas where humans live. These behaviours increase the likelihood of human contact with wildlife, the insects they host, and the diseases they carry.

Drought reduces the size of water bodies and causes them to become stagnant. This provides additional breeding grounds for certain types of mosquitoes. Inadequate water supply can cause people to collect rainwater. This can lead to collections of stagnant water that can become manmade mosquito breeding areas.

Health Implications of Drought: Mental Health and Psychosocial Support

Micronutrient deficiencies (e.g. lack of iron) and poor psychosocial support during periods of disasters such as drought and famine can inhibit cognitive and physical development of children which in turn leads to a life time of intellectual disability. This may be a result of parents being too physically or mentally unwell to care for their young off-springs.

A combination of responsive parenting and the emphasis of the provision of good nutrition is an effective intervention. It is important for health professionals to differentiate the normal psychological stresses of people being affected by disasters. The distress caused by uncertainty and fear burdens people of all ages and as such the provision of Psychological First Aid and Psychosocial support is important.

Sources:

  • Centers for Disease Control and Prevention, U.S. Environmental Protection Agency, National Oceanic and Atmospheric Agency, and American Water Works Association. 2010. When every drop counts: protecting public health during drought conditions—   a guide for public health professionals. Atlanta: U.S. Department of Health and Human Services
  • http://www.cdc.gov/nceh/drought/default.htm
  • Information Sheet No 126/2003, List of Droughts in Fiji from 1965 – 2000, Climate Division, Fiji Met Office
  • Public Health Risk Assessment and Interventions: The Horn of Africa Drought and Famine Crisis July 2011
  • UNISDR, 2009. Drought Risk Reduction Framework and Practices: Contributing to the Implementation of the Hyogo Framework for Action. United Nations secretariat of the International Strategy for Disaster Reduction (UNISDR), Geneva, Switzerland, 213 pp.

 

 

 

 

Dengue Interventions by a small mosquito control unit

Written By: Website Administrator

31/03/2014

Article By: Vimal Deo

According to World Health Organization, preventing or reducing dengue virus transmission depends entirely the control of the mosquito vectors or interruption of human–vector contact.

In essence, the prevention and control activity for dengue fever is centred on the control of the transmitting vector or agent i.e. the mosquito.  Past research in Fiji and various published report identified Aedesaegypti mosquitoes as the most effective vector for dengue fever. The mosquito prefers to inhabit close to household and immediate vicinity of its food source (blood meal), as well as other settings (such as schools, hospitals and workplaces). Therefore, the dengue, fever Interventions are focused on eliminating or at least reducing the population of mosquitoes around areas where humans habitat.

The World Health Organization recommends an integrated vector management (IVM) as the strategic approach for vector control. IVM is defined as “a rational decision-making process for the optimal use of resources for vector control”. The Integrated Vector Management (IVM) considers five key elements in the management process, namely:

(i)         Advocacy, social mobilization and legislation

(ii)        Collaboration within the health sector and with other sectors

(iii)       Integrated approach to disease control

(iv)       Evidence-based decision-making

(v)        Capacity-building

According to a recent review on the Vector Control initiatives by a WHO Consultant (Unpublished 2014), Fiji has a long history of dealing with dengue (since 1885) and has  a leading dengue vector control program in the Melanesia and Pacific region. Whilst the consultant noted that there is a high level of knowledge and awareness of dengue amongst the health leadership and staff, there is scope to provide additional resources to increase mobility and technical capacity of the teams.

Despite limitations, the overall aim for vector control has been to eliminate all potential breeding habits of mosquitoes through effective vector reduction campaign in the high risk urban and rural areas within the operational health division’s placing greater emphasis on source reduction through basic environmental health approaches and community mobilization. This is implemented through:

(i)                 Vector reduction campaign via clean-up of compounds / backyard , overgrowth in vacant lots and blocked drains

(ii)               Cartage of refuse in dengue sensitive and high risk areas within the rural areas

(iii)             Mobilization of community to sustain clean and vector free environment

Intersectoral collaboration through a National Dengue Clean-Up Initiative which is places emphasis on destroying mosquito breeding in tyres, drums and other receptacles that can retain water.

Apart from source reduction, vector control can be achieved through good water supply and storage measures (mosquito proofing water storage containers), good solid waste management practices (ensuring that potential water retaining receptacles are properly disposed), and through the use of chemical controls. Chemical controls are usually done through spraying which ideally targets adult mosquitoes and through larviciding which targets immature mosquito larvae. In addition, entomological monitoring and surveillance through the monitoring of vector populations through larval and adult mosquito monitoring coupled with timely feedbacks are essential for dengue prevention and control.

A final tool that is available for effective dengue control is through the use of legislative advocacy and implementation of legislative authority. Simply put, imposing of fines to persons who harbour or breed mosquitoes. The limitations to such an approach are the long awaited court processes and associated court costs to resolve an eminent threat.

Finally, dengue Fever is preventable, but no prevention is 100% effective. Some of the best means of prevention starts with an individual mindset towards self-protection. Some of these prevention measures include minimizing mosquito bites, avoiding mosquito-prone areas and using of repellents. Apart from these, source reduction through elimination of mosquito breeding sites is the best course in prevention dengue.

It is only through the combination of these efforts successful dengue control can be achieved.

Reference:

1. Dengue: guidelines for diagnosis, treatment, prevention and control — New edition (2009), World Health Organization.