An assessment of the usefulness of a rapid immuno-chromatographic test, "Determine™ malaria pf" in evaluation of intervention measures in forest villages of central India

BACKGROUND: Plasmodium falciparum malaria, is a major health problem in forested tribal belt of central India. Rapid and accurate methods are needed for the diagnosis of P. falciparum. We performed a blinded evaluation of the recently introduced Determine™ malaria pf test (Abbott, Laboratories, Japan) compared with microscopy and splenomegaly in children in epidemic prone areas of district Mandla to assess the impact of intervention measures. METHODS: Children aged 2–10 yrs with and without fever were examined for spleen enlargement by medical specialist by establishing a mobile field clinic. From these children thick blood smears were prepared from finger prick and read by a technician. Simultaneously, rapid tests were performed by a field lab attendant. The figures for specificity, sensitivity and predictive values were calculated using microscopy as gold standard. RESULTS: In all 349 children were examined. The sensitivity and specificity for Determine rapid diagnostic test were 91 and 80% respectively. The positive predictive values (PPV), negative predictive values (NPV) and accuracy of the test were respectively 79, 91 and 85%. On the contrary, the sensitivity and specificity of spleen in detecting malaria infection were 57 and 74 % respectively with PPV of 73%, NPV 59 % and an accuracy of 65%. CONCLUSIONS: Determine™ malaria rapid diagnostic test is easier and quicker to perform and has other advantages over microscopy in not requiring prior training of personnel or quality control. Thus, highlighting the usefulness of a rapid antigen test in assessing prevailing malaria situation in remote areas

Understanding Human-Plasmodium falciparum Immune Interactions Uncovers the Immunological Role of Worms

BACKGROUND: Former studies have pointed to a monocyte-dependent effect of antibodies in protection against malaria and thereby to cytophilic antibodies IgG1 and IgG3, which trigger monocyte receptors. Field investigations have further documented that a switch from non-cytophilic to cytophilic classes of antimalarial antibodies was associated with protection. The hypothesis that the non-cytophilic isotype imbalance could be related to concomittant helminthic infections was supported by several interventions and case-control studies. METHODS AND FINDINGS: We investigated here the hypothesis that the delayed acquisition of immunity to malaria could be related to a worm-induced Th2 drive on antimalarial immune responses. IgG1 to IgG4 responses against 6 different parasite-derived antigens were analyzed in sera from 203 Senegalese children, half carrying intestinal worms, presenting 421 clinical malaria attacks over 51 months. Results show a significant correlation between the occurrence of malaria attacks, worm carriage (particularly that of hookworms) and a decrease in cytophilic IgG1 and IgG3 responses and an increase in non-cytophilic IgG4 response to the merozoite stage protein 3 (MSP3) vaccine candidate. CONCLUSION: The results confirm the association with protection of anti-MSP3 cytophilic responses, confirm in one additional setting that worms increase malaria morbidity and show a Th2 worm-driven pattern of anti-malarial immune responses. They document why large anthelminthic mass treatments may be worth being assessed as malaria control policies

The history of leishmaniasis

In this review article the history of leishmaniasis is discussed regarding the origin of the genus Leishmania in the Mesozoic era and its subsequent geographical distribution, initial evidence of the disease in ancient times, first accounts of the infection in the Middle Ages, and the discovery of Leishmania parasites as causative agents of leishmaniasis in modern times. With respect to the origin and dispersal of Leishmania parasites, the three currently debated hypotheses (Palaearctic, Neotropical and supercontinental origin, respectively) are presented. Ancient documents and paleoparasitological data indicate that leishmaniasis was already widespread in antiquity. Identification of Leishmania parasites as etiological agents and sand flies as the transmission vectors of leishmaniasis started at the beginning of the 20th century and the discovery of new Leishmania and sand fly species continued well into the 21st century. Lately, the Syrian civil war and refugee crises have shown that leishmaniasis epidemics can happen any time in conflict areas and neighbouring regions where the disease was previously endemic

Fleas as parasites of the family Canidae

Historically, flea-borne diseases are among the most important medical diseases of humans. Plague and murine typhus are known for centuries while the last years brought some new flea-transmitted pathogens, like R. felis and Bartonella henselae. Dogs may play an essential or an accidental role in the natural transmission cycle of flea-borne pathogens. They support the growth of some of the pathogens or they serve as transport vehicles for infected fleas between their natural reservoirs and humans. More than 15 different flea species have been described in domestic dogs thus far. Several other species have been found to be associated with wild canids. Fleas found on dogs originate from rodents, birds, insectivores and from other Carnivora. Dogs therefore may serve as ideal bridging hosts for the introduction of flea-borne diseases from nature to home. In addition to their role as ectoparasites they cause nuisance for humans and animals and may be the cause for severe allergic reactions