Report on malaria cases from 2002 till 2009

In an hyper-endemic area like the one we live in, the proportion of people detected with positive blood smear is relatively constant throughout the year, but the majority of cases still do occur during the wet season, given the fact that malaria is a ‘rainy season disease’.Our monthly data collection from 2002 till 2009 (picture 1) confirm the above statement, presenting a relatively constant number of probable malaria cases each month of the year, with an increase on the positive malaria cases right after the rainy season especially the first  

four years before the Long-Lasting Insecticidal mosquito Nets (LLINs) started to be distributed in our region. After the distribution of the LLINs in 2006, the diagnosed positive malaria cases were again constant each month of the year, but the positive cases are distributed equally all year long, without the strong variation noticed in the first four years the months after the rainy season. 

Picture 1: Malaria cases at Cottolengo Mission Hospital since 2002. The probable malaria cases are indicated in blue, while the confirmed positive ones in red. The same scale was used in all graphs. 

Except from the stabilized situation noticed on monthly level for the diagnosed positive malaria cases right after the distribution of the LLINs in 2006, our data manifest a decrease not only in the number of probable malaria cases after 2006, but also a decrease in the number of detected positive malaria cases. The above statement can be easily seen on the following graph (picture 2), which represents probable malaria cases and positive-detected malaria cases from 2002 till 2009. A careful look on these data leads to the observation that, in 2002 the probable malaria patients reached a total number of 32.722 with a percentage of positive ones reaching  70% of the number of total patients, with the same more or less total number of patients observed the years following 2002 until 2006, in which the probable malaria cases were 23.801 in total, with a percentage of 34% diagnosed positive ones. From this year on, not only the number of total patients is decreased in comparison with those observed on 2002, but also the number of positive confirmed malaria cases. 

Picture 2:  Malaria cases at Cottolengo Mission Hospital since 2002.  Probable malaria cases are shown in blue color, and the confirmed positive malaria cases in red. The percentage of the confirmed positive malaria cases is also shown for each year from 2002 till 2009. 

The decrease on the probable malaria cases shown above probably takes place because for us a fever case does not equally mean a malaria case. Investigating the symptoms of the patients, we now more than ever try to make the best diagnosis possible before we sent the patient for the thick blood slide test for malaria parasite. Additionally, the decrease on the number of the positive malaria cases after 2006 can be interpreted from the fact that more trustful equipment was used in the laboratory of our hospital in order to detect malaria parasites, the skills of our laboratory technicians were improved and a continuous training of them takes place more often. But, according to our opinion, the factor that has the most important impact in the decrease of the positive malaria cases is the LLINs distributed in our region, as mentioned before. If we would like to compare the first year that we could get correct data on malaria cases on 2002, with last-year’s malaria cases, this decrease on the positive detected cases is very obvious. As shown in picture 3, the percentage of the malaria patients reached an about 70% of the 32.722 total number of probable malaria patients in 2002, leaving only a 30% of them as negative ones, whereas on 2009, the percentage of the positive malaria patients was found only about 30% of the 15.363 total number of probable malaria patients. The data indicate that the positive malaria cases in 2002 were reversed with the negative ones in 2009. 

Picture 3: Comparison of malaria cases at Cottolengo Mission hospital on 2002 and 2009. Positive cases are shown in blue color whereas negative ones in dark red. Total number of patients is referred respectively for each year. 

The advent of long-lasting insecticidal nets (LLINs) and a careful and proper malaria treatment represent a new opportunity for malaria control in our region. But despite the supply of mosquito nets in our area, the number available so far was still far below our needs. Actually we have distributed so far LLINs only to pregnant women and women with a child younger than 5 years old, which are the groups of people most vulnerable to malaria.

Picture 4: Malaria cases at Cottolengo Mission hospital in January 2010. The percentage of the positive malaria cases is shown respectively for each group.  

As it is shown in the above graph (picture 4), the percentage of the positive malaria cases in infants and children is lower than those observed in older groups, resulted from the distribution of the bed-nets in our area. Hopefully, good surveillance and high intervention coverage with bed nets will help reduce malaria burden even more the following years. Because after all, the best method to fight malaria is to prevent the main form of transmission: mosquitoes.

Dr. Br. Giuseppe Gaido