Plasmodium transmission blocking activities of Vernonia amygdalina extracts and isolated compounds.

Background: Medicinal plants are a validated source for discovery of new leads and standardized herbal medicines. The aim of this study was to assess the activity of Vernonia amygdalina leaf extracts and isolated compounds against gametocytes and sporogonic stages of Plasmodium berghei and to validate the findings on field isolates of Plasmodium falciparum.

Methods: Aqueous (Ver-H2O) and ethanolic (Ver-EtOH) leaf extracts were tested in vivo for activity against sexual and asexual blood stage P.

Impact of repeated NeemAzal-treated blood meals on the fitness of Anopheles stephensi mosquitoes.

Background: Herbal remedies are widely used in many malaria endemic countries to treat patients, in particular in the absence of anti-malarial drugs and in some settings to prevent the disease. Herbal medicines may be specifically designed for prophylaxis and/or for blocking malaria transmission to benefit both, the individual consumer and the community at large. Neem represents a good candidate for this purpose due to its inhibitory effects on the parasite stages that cause the clinical manifestations of malaria and on those responsible for infection in the vector.

Enabling factors facilitating the use of neem-based remedies for the management of malaria in the Lower Shire District of Chikwawa, Malawi.

Background: Malaria remains a major public health threat in Malawi, affecting mostly children under five and pregnant women. Despite the availability of chemotherapy and chemoprophylaxis, resistance to sulfadoxine pyrimethamine and the high cost and complicated regimen of artemether-lumefantrine have accelerated the use of home-based remedies for the management of malaria in Chikwawa district, Malawi. This study aimed to determine factors that facilitate the use of herbal remedies within communities in the management of malaria in the presence of free health care services, with the intention of assessing the feasibility of developing improved herbal products as anti-malarial prophylaxis.

A user friendly method to assess Anopheles stephensi (Diptera: Culicidae) vector fitness: fecundity.

Fecundity, bloodmeal size, and survival are among the most important parameters in the overall fitness of mosquitoes. Impact of an intervention that affects fecundity can be assessed by directly counting the eggs laid by exposed mosquitoes, which is usually done manually. We have developed a macroinstruction, which can be used to count thousands of Anopheles stephensi Liston eggs in a few minutes, to provide an alternative and adaptable method to egg counting as a measure of fecundity.

HIV-1 infection and antibodies to Plasmodium falciparum in adults.

Background: Coinfection with human immunodeficiency virus (HIV) may increase susceptibility to malaria by compromising naturally acquired immunity.

Methods: In 339 adults (64% HIV infected), we measured antibodies to Plasmodium falciparum variant surface antigens (VSA) and antibodies that opsonise infected erythrocytes using parasite lines FCR3, E8B, and R29, and antibodies to merozoite antigens AMA-1 and MSP2. We determined the relationship between malaria antibodies, HIV infection, markers of immune compromise, and risk of incident parasitemia.

Community health workers' perceptions of barriers to utilisation of malaria interventions in Lilongwe, Malawi: A qualitative study.

Background: In line with increased advocacy for implementation of malaria interventions at community level, universal net coverage has become a prominent intervention in Lilongwe, Malawi. However, beliefs and perceptions about malaria interventions have greatly affected the implementation of interventions at community level. This study explored the perception of community health workers in Lilongwe on barriers to effective malaria control service delivery and utilisation at the community level.

Impact of human immunodeficiency virus infection in pregnant women on variant-specific immunity to malaria.

Human immunodeficiency virus (HIV) increases susceptibility to Plasmodium falciparum infection, and this has most clearly been demonstrated in pregnant women. Variant surface antigens on the surfaces of erythrocytes infected with P. falciparum are major targets of protective immunity.

Are Plasmodium falciparum parasites present in peripheral blood genetically the same as those sequestered in the tissues?

Since quinine does not inhibit the growth of Plasmodium falciparum ring stages or mature schizonts, parasites may continue to emerge from sequestration sites after starting treatment. We used polymerase chain reaction amplification of P. falciparum merozoite surface protein 1 (MSP-1) and MSP-2 alleles to distinguish genotypes infecting 58 children with severe malaria.