Defining malaria burden from morbidity and mortality records, self treatment practices and serological data in Magugu, Babati District, northern Tanzania

Abstract

Malaria morbidity and mortality data from clinical records provide essential information towards defining disease burden in the area and for planning control strategies, but should be augmented with data on transmission intensity and serological data as measures for exposure to malaria. The objective of this study was to estimate the malaria burden based on serological data and prevalence of malaria, and compare it with existing self-treatment practices in Magugu in Babati District of northern Tanzania. Prospectively, 470 individuals were selected for the study. Both microscopy and Rapid Diagnostic Test (RDT) were used for malaria diagnosis. Seroprevalence of antibodies to merozoite surface proteins (MSP-119) and apical membrane antigen (AMA-1) was performed and the entomological inoculation rate (EIR) was estimated. To complement this information, retrospective data on treatment history, prescriptions by physicians and use of bed nets were collected. Malaria prevalence in the area was 6.8% (32/470). Of 130 individuals treated with artemisinin combination therapy (ACT), 22.3 % (29/130) were slide confirmed while 75.3% (98/130) of them were blood smear negative. Three of the slides confirmed individuals were not treated with ACT. Fever was reported in 38.2% of individuals, of whom 48.8 % (88/180) were given ACT. Forty-two (32.3%) of those who received ACT had no history of fever. About half (51.1%) of those treated with ACT were children <10 years old. Immunoglobulin against MSP-119 was positive in 16.9% (74/437) while against AMA-1 was positive in 29.8 % (130/436). Transmission intensity was estimated at <0.2 infectious bites per person per year. The RDT was highly specific (96.3%) but with low sensitivity (15.6%). In conclusion, Magugu is a low endemic area. There is substantial over diagnosis, over treatment and self treatment in the community. The burden of malaria based on medical records is over estimated as was mostly presumptive. The low sensitivity of RDT reflects the low number of immune individuals as well as the low parasite density. ________________________________________________________________________________

Prevalence of plasmodium, leptospira and rickettsia species in Northern Tanzania: a community based survey

“…This study also found no Plasmodium infection in Magugu, which means that the prevalence might be at a very low rate, despite a favorable and suggestive climate for malaria endemicity. This result is in confluence with a previous study which also reported low prevalence of malaria in Magugu 23 and with National Malaria Survey which reported prevalence of <1% in Manyara region 24 . Zero prevalence of Plasmodium infection reported from Magugu by this study, can be explained from different perspectives, one of which could be the use of Magugu site as a trial site for pesticide efficacy studies.…”

Prevalence of Plasmodium falciparum and Salmonella typhi Infection and Coinfection and Their Association With Fever in Northern Tanzania

“…Diagnoses are frequently provisional in the absence of adequate confirmatory tests, and it is, therefore, a common practice that antimicrobials are irrationally prescribed, leading to serious consequences, including the development of antimicrobial resistance. 20,21 This scenario justifies the application of high-throughput and highly sensitive molecular tools to determine the causes of diseases with overlapping clinical signs and for proper management of febrile illness. About half of the participants in Bondo had P. falciparum parasitaemia.…”

“…Support for malaria control at both the national and district levels has increased considerably over the past few years. The low prevalence of P. falciparum infection in Magugu has been reported for about a decade, 11,20,24 likely because Magugu serves as an experimental study site for a national pesticide research institute. 25 The prevalence of S. typhi infection in Bondo was high, with about one-fifth of the population testing positive for S. typhi, while in Magugu, about one-tenth of individuals were found to be infected with S. typhi.…”

Prevalence of dengue and chikungunya virus infections in north-eastern Tanzania: a cross sectional study among participants presenting with malaria-like symptoms

“…We did observe quite a low number of mRDT positives in the 3 sites; preliminary data suggest that, as expected, a fraction of the mRDT negatives are plasmodium positive when using a sensitive PCR method (data not shown), and therefore the low parasitaemi as are having no impact on fever/symptoms observed in participants, nevertheless after excluding all malaria positive, we found that 38.0 % of the remaining participants reported fever. It is known that in many malaria endemic areas where clear diagnosis cannot be established, all fevers may still be treated as malaria [ 53 ]. Therefore, we recommend establishment of better diagnosis of fever to avoid over-treatment of other diseases.…”