MALARIA EPIDEMICS:

A NATURAL DISASTER IN SOUTHERN AFRICA

Introduction

Malaria and malaria epidemics are a major public health problem experienced in countries within the Southern African region. Despite being preventable and curable it is one of the largest killers in Africa. With renewed international support mobilised by WHO, from the affected countries and those who support them, efforts to control malaria and reduce malaria infections are increasing for the next century.

Depending upon the local social and environmental conditions of an area, malaria can be endemic (all year round), seasonal (increased cases occur as a result of the seasonal rains) or a combination of the two (year round malaria with seasonal increases).  While endemic malaria consistently drains the health services resources through the treatment of casualties, it is the seasonal malaria with localised epidemics, which for short periods actually creates the crisis imposing the most stress on the health systems ability to cope.

Seasonal increases are often mistaken as ‘epidemic malaria’.  In the literal sense this is indeed true.  Defined as ‘attacking or infecting many persons simultaneously in a community’ or ‘the rapid development, spread or growth of something unpleasant’ [i] , seasonal increase certainly fits the definition.  But unfortunately this use of the term does not give justice to the situations also described as an epidemic, situations when the cases and deaths exceed the norm [ii] .  Within the field of disaster studies, the term epidemic is used to describe a medical disaster resulting from a disease outbreak, which although different from the literal definition, fits more closely to the common understanding of an epidemic.  In fact, in order to avoid confusing the seasonal increase with the more serious epidemic, it is necessary to develop a new term,
  ‘the malaria epidemic disaster’, a malaria epidemic with the magnitude of a disaster, which exceeds the local capacity to cope despite preparations for the anticipated seasonal increase.[iii]  By comparison, a general case definition for epidemic malaria suggests that it is ‘the occurrence of malaria cases in excess of the number expected at a given place in a give time.’A malaria epidemic disasters can be defined as a slow onset disaster.  This is a disaster that can be anticipated, prepared for and identified before it peaks and therefore response activities can be undertaken before the peak of the disaster, reducing its magnitude, and consequently, the number of infections and loss of life.

The Malaria Epidemic Disaster Cycle

When considering a malaria epidemic, it is possible to break the event down into six separate phases, excluding the impact point, as shown in the diagram overleaf.

The phases are simplified into independent sections that suggest clear-cut distinctions between each phase. In reality, this is not the case as the various phases are
inter-linked. Nevertheless, the model helps to illustrate a methodological approach to epidemic disasters.

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1. Forecasting

A relatively new development in malaria control, this phase is undertaken many months prior to the malaria increase to provide a strategic overview of the forthcoming malaria season.  The information can be based upon an analysis of historic malaria data together with environmental and ecological data to identify where previous problems have occurred. Analysis of the various meteorological forecasts can provide a forecast of the suitability of the environmental conditions for malaria transmission. Ideally, a combination of the two will be used with historical information collated and analysed at all levels of the health system (national, provincial and district).

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2. Prevention

Also described as mitigation within disaster studies, prevention is the phase that will incorporate all activities undertaken to reduce the anticipated severity and impact of a malaria epidemic.  This will include health education and personal protection at the community level and selective vector control activities. Undertaken some months before the seasonal increase and possible epidemic occurrence, it is possible to include prevention activities such as malaria hazard mapping and the timely re-treatment of mosquito nets

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3. Preparedness

Preparedness activities are those which improve the capacity to respond to an epidemic.  In the case of malaria epidemic response it will include the identification of potential sites for field clinics and the identification of emergency volunteers and emergency trained support teams. Preparation should also include ensuring additional stocks of drugs for treatment and prophylaxis [iv] , and chemicals for vector control and larviciding. It is also possible to have stocks of repellents and other personal protection equipment for free distribution to epidemic hotspot areas.  When preparing it is advantageous to inform military and civil defence partners of the anticipated season to allow them time to prepare and plan a response, should the need arise.

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4. Early Warning

Early warning is an aspect of epidemic control that is extremely valuable but which is currently underused. Traditional early warning systems rely upon disease surveillance systems where they exist or simply human judgements and information referral where they do not. It is possible to monitor cases at the local level, with locally defined thresholds for different levels of the problem. Low risk, medium risk, high risk and epidemic thresholds will then provide the health team with the figures and levels to initiate an early response before the problem escalates to epidemic proportions.

Developing forecasting further, it is possible to go beyond this level, and to incorporate GIS and remote sensing tools to analyse environmental and meteorological data such as NDVI (Normalised Difference Vegetation Index) and CCD (Cold Cloud Duration) to identify micro climatic changes.  Such Systems have the ability to pin point potential problem areas over a large scale much sooner, Providing greater warning but are to date, still being refined, but even now it is possible to monitor weekly changes in rainfall and temperature as a guide to malaria epidemic hotspots.

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5. Response

The Response phase is broken down in the diagram into early response, impact and then response.  This is essential to illustrate that response does not have to be reactive to a problem, it can also be proactive to information and early warnings.

When responding there are two critical stages, assessment and relief.

Rapid Assessment

To avoid as many delays as possible, it is advantageous to respond to requests from the ground as they are made, and to support them with assessments which can then redefine or support response activities.  The assessment allows for an educated and informed response.  Without an assessment, a response effort will be ill-informed and possibly futile if it does not address the problems on site.

Response - Control

It is critical that a variety of activities are available and utilised as the situation dictates. Approaches in the response phase could include intensive health education in the hotspot areas; improved access to treatment through volunteer community workers and satellite field clinics; indoor residual spraying or larviciding, if appropriate; improved diagnosis at epidemic referral centres and the provision of personal protection at subsidised prices or at no cost in the hotspot areas. Which ever approach is utilised, it should be justified by an assessment and reviewed by an evaluation to help improve response activities in the future. 

Critical to the success of a true epidemic response is the extra support to assist in the control activities. In order to access this additional support, it is necessary to declare a problem as and when it occurs.  A public health declaration is not a statement of failure, it is a request for such support. Support and public interest can be maintained through regular press releases and conferences. Combined with other education activities, this can help mobilise affected communities and reduce malaria mortality.

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6. Post-mortem and Report

This section needs little explanation except that without it, improvements in future response efforts in the future will be few and far between as will funds for these efforts.

A Team Effort

Essential throughout all of the above phases is good co-ordination, co-operation and collaboration.  A malaria epidemic disaster is a dynamic and complicated event that requires many hands and approaches to conclude.  An epidemic disaster is no different to any other disaster, and yet it is usually co-ordinated and responded to by the Ministry of Health alone.  It is essential to identify and include other partners, such as the civil protection units, in planning a response from the very beginning.

In conclusion, the response to a malaria epidemic disaster is a multifaceted one.  It should include both proactive and reactive components. During the response phase, the stress levels on the health system will be high. Preparedness activities undertaken before the epidemic disaster will relieve some of this pressure and assist in avoiding obvious mistakes that may well cost lives. Use checklists, plan ahead and consider any actions before the rise in malaria transmission occurs.

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