BY NEW BUSINESS ETHIOPIA REPORTER
Malaria cases increased in three African countries in 2009 (Rwanda, Sao Tome and Principe, and Zambia), while malaria burden has been reduced globally, a new report released this week reveals.
The reasons for the resurgences are not known with certainty, according to the ‘World Malaria Report 2010”, which summarized information received from 106 malaria-endemic countries.
The report indicated that increases in malaria cases highlight the fragility of malaria control and the need to maintain control programs even if numbers of cases have been reduced substantially.
“The experiences in Rwanda and Zambia also indicate that monthly monitoring of disease surveillance data, both nationally and sub-nationally is essential. Since many countries in sub-Saharan Africa had inadequate data to monitor disease trends, it is apparent that greater efforts need to be made to strengthen routine surveillance systems. Major epidemiological events could be occurring in additional countries without being detected and investigated,” the report noted.
Globally, the number of cases of malaria rose from 233 million in 2000 to 244 million in 2005 but decreased to 225 million in 2009. The number of deaths due to malaria is estimated to have decreased from 985 000 in 2000 to 781 000 in 2009.
The report also stated that, the largest absolute decreases in deaths were observed in Africa while in 2009, the European Region reported no cases of P. falciparum malaria for the first time.
Decreases in malaria burden have been observed in all WHO Regions, with the largest proportional decreases noted in the European Region, followed by the Region of Americas.
The increased financing has resulted in tremendous progress in increasing access to insecticide-treated mosquito nets (ITNs) in the past 3 years. By the end of 2010, approximately 289 million ITNs will have been delivered to sub-Saharan Africa, enough to cover 76 percent of the 765 million persons at risk of malaria.
The report estimated that 42 percent of households in Africa owned at least one ITN in mid-2010, and that 35 percent of children slept under an ITN.
The percentage of children using ITNs is still below the WHA target of 80 percent partly because up to the end of 2009, ITN ownership remained low in some of the largest African countries.
Low rates of use reported in some surveys are primarily due to a lack of sufficient nets to cover all household members; household survey results suggest that most (80 percent) of the available ITNs are used.
While the rapid scale-up of ITN distribution in Africa represents an enormous public health achievement, it also represents a formidable challenge for the future in ensuring that the high levels of coverage are maintained.
The lifespan of a long-lasting ITN is currently estimated to be 3 years. Nets delivered in 2006 and 2007 are therefore already due for replacement, and those delivered between 2008 and 2010 soon will be. Failure to replace these nets could lead to a resurgence of malaria cases and deaths.
IRS programs have also expanded considerably in recent years, with the number of people protected in sub-Saharan Africa increasing from 13 million in 2005 to 75 million in 2009, corresponding to protection for approximately 10% of the population at risk in 2009.
Current methods of malaria vector control are highly dependent on a single class of insecticides, the pyrethroids, which are the most commonly used compounds for IRS and the only insecticide class used for ITNs.
The widespread use of a single class of insecticide increases the risk that mosquitoes will develop resistance, which could rapidly lead to a major public health problem.
“The risk is of particular concern in Africa, where insecticidal vector control is being deployed with unprecedented levels of coverage and where the burden of malaria is greatest,” noted World Malaria Report 2010.