Detecting Plasmodium falciparum in community surveys: a comparison of Paracheck Pf® Test and ICT Malaria Pf® Cassette Test to polymerase chain reaction in Mutasa District, Zimbabwe.

Background: Microscopy and rapid diagnostic tests (RDTs) are the main techniques used to diagnose malaria. While microscopy is considered the gold standard, RDTs have established popularity as they allow for rapid diagnosis with minimal technical skills. This study aimed to compare the diagnostic performance of two Plasmodium falciparum histidine-rich protein 2 (PfHRP2)-based RDTs (Paracheck Pf® Test (Paracheck) and Malaria Pf™ ICT (ICT)) to polymerase chain reaction (PCR) in a community survey.

Steep Rebound of Chloroquine-Sensitive Plasmodium falciparum in Zimbabwe.

Removal of chloroquine from national malaria formularies can lead to the reversion of resistant Plasmodium falciparum to wild-type. We report a steep decline in chloroquine-resistant P falciparum within 10 years of national discontinuation of chloroquine monotherapy in Zimbabwe. Drug resistance surveillance is a vital component of malaria control programs, and the experience with chloroquine in Zimbabwe and elsewhere in sub-Saharan Africa is illustrative of the potentially rapid and dramatic impact of drug policy on antimalarial resistance.

Inclusion of edaphic predictors for enhancement of models to determine distribution of soil-transmitted helminths: the case of Zimbabwe.

Background: Reliable mapping of soil-transmitted helminth (STH) parasites requires rigorous statistical and machine learning algorithms capable of integrating the combined influence of several determinants to predict distributions. This study tested whether combining edaphic predictors with relevant environmental predictors improves model performance when predicting the distribution of STH, Ascaris lumbricoides and hookworms at a national scale in Zimbabwe.

Methods: Geo-referenced parasitological data obtained from a 2010/2011 national survey indicating a confirmed presence or absence of STH among school children aged 10-15 years was used to calibrate ten species distribution models (SDMs).

Distribution of schistosomiasis and soil transmitted helminthiasis in Zimbabwe: towards a national plan of action for control and elimination.

Background: Schistosomiasis and STH are among the list of neglected tropical diseases considered for control by the WHO. Although both diseases are endemic in Zimbabwe, no nationwide control interventions have been implemented. For this reason in 2009 the Zimbabwe Ministry of Health and Child Care included the two diseases in the 2009-2013 National Health Strategy highlighting the importance of understanding the distribution and burden of the diseases as a prerequisite for elimination interventions.

Changes in the burden of malaria following scale up of malaria control interventions in Mutasa District, Zimbabwe.

Background: To better understand trends in the burden of malaria and their temporal relationship to control activities, a survey was conducted to assess reported cases of malaria and malaria control activities in Mutasa District, Zimbabwe.

Methods: Data on reported malaria cases were abstracted from available records at all three district hospitals, three rural hospitals and 25 rural health clinics in Mutasa District from 2003 to 2011.

Results: Malaria control interventions were scaled up through the support of the Roll Back Malaria Partnership, the Global Fund to Fight AIDS, Tuberculosis and Malaria, and The President's Malaria Initiative.

Evaluation of "Cyscope", a novel fluorescence-based microscopy technique for the detection of malaria.

Introduction: This study was designed to compare the detection of malaria parasites in peripheral blood smears using the Cyscope malaria rapid fluorescent microscopic technique and light microscopy of Giemsa-stained smears.

Methodology: A total of 295 blood smears were collected from patients of all age groups presenting with clinical signs and symptoms of malaria to 10 City Health Clinics in Harare. For each patient two blood films were prepared.

Analysis of genetic polymorphism in select vaccine candidate antigens and microsatellite loci in Plasmodium falciparum from endemic areas at varying altitudes.

Plasmodium falciparum parasites obtained from symptomatic patients attending clinics in Bindura (altitude 1100 m), Chiredzi (600 m) and Kariba (<600 m), previously reported to differ in malaria endemicity were genotyped on the msp-1, msp-2 and glurp loci to examine the extent of parasite genetic diversity. While the parasites were monomorphic for msp-1 allele RO33 from the three locations, the K1 allele was over-represented in Kariba (p=0.02) and Mad20 alleles occurred at a higher frequency in Bindura.

High prevalence of molecular markers for resistance to chloroquine and pyrimethamine in Plasmodium falciparum from Zimbabwe.

Chloroquine has been the first line drug of treatment for malaria in Zimbabwe until a recent adoption of an interim policy to treat using a combination of chloroquine (CQ) and sulfadoxine/pyrimethamine (SP). We examined the prevalence of parasites with mutations associated with resistance to the drug combination in three areas that have been previously described to differ in malaria endemicity. Our results show that the parasite population from the three areas had a high prevalence of molecular markers of resistance to chloroquine and pyrimethamine.

Antibody responses to Plasmodium falciparum vaccine candidate antigens in three areas distinct with respect to altitude.

Antibody levels against malaria antigens were measured among patients presenting with uncomplicated malaria at health centers from three locations in Zimbabwe (Bindura, Chiredzi and Kariba) that are distinct with regard to altitude and climatic conditions. Antibody levels were determined by ELISA using the antigens, apical membrane antigen 1 (AMA-1), erythrocyte binding antigen 175 (EBA-175), circumsporozoite surface protein (CSP), merozoite surface protein 1 (MSP-1) and Pfg27. For all the antigens tested, IgG and IgM levels were higher for Bindura (altitude 1100 m) compared to Kariba (<600 m, altitude) and Chiredzi (approximately 600 m, altitude) with the exception of IgG and IgM to AMA-1 and EBA-175 which were similar between Chiredzi and Bindura.

Association of house spraying with suppressed levels of drug resistance in Zimbabwe.

Background: Public health strategies are needed to curb antimalarial drug resistance. Theoretical argument points to an association between malaria transmission and drug resistance although field evidence remains limited. Field observations, made in Zimbabwe, on the relationship between transmission and multigenic drug resistance, typified by chloroquine, are reported here.