Parasite density and malaria morbidity in the Pakistani Punjab.

Abstract

Abstract.The relationship between quantitative Plasmodium falciparum or P. vivax parasitemia and clinical illness has not been defined in Pakistan or in other areas where malaria transmission is not highly endemic. Standardized questionnaires were given to and physical examinations and parasitologic tests were performed in 8,941 subjects seen in outpatient clinics in 4 villages for 13 consecutive months in the Punjab region of Pakistan. The results, based on multivariable analysis, showed that a clinical diagnosis of malaria, a history of fever, rigors, headache, myalgia, elevated temperature, and a palpable spleen among children were all strongly associated with the presence and density of P. falciparum or P. vivax malaria in a monotonic dose-response fashion. The malaria attributable fraction of a clinical diagnosis of malaria, and the same symptoms and signs also increased with increasing P. falciparum and, to a lesser extent, P. vivax, parasitemia. Unlike in sub-Saharan Africa, clinical illness due to malaria often occurs in the Punjab among adolescents and adults and in patients with parasite densities less than 1,000/l. Clinical guidelines based upon parasitemia and symptomatology must be adjusted according to the intensity of transmission and be specific for each geographic area. Morbidity and mortality have been strongly linked toPlasmodium falciparum parasite density and guidelines have been introduced for etiologic classification of febrile illnesses and for therapeutic regimens based upon density of parasites in the blood. While P. falciparum is the predominant species in sub-Saharan Africa, where most of the studies comparing clinical illness with intensity of infection have been conducted, 1-6 malaria in southern Asia and many other endemic areas is caused by both P. falciparum and P. vivax and is characterized by a much lower sporozoite inoculation rate. The relationship between parasite density and clinical illness in such an environment has not been defined as it has been in Africa. Also, the impact of increasing P. vivax parasite density on clinical disease has not been studied as rigorously as has P. falciparum.

Genetic diversity in human malarial parasites of Khyber Agency Pakistan

“…The parasite density is strongly associated with a clinical diagnosis of malaria for all species of malaria. In our study the average parasite density was 2050 parasites/μl which are comparable with the study observed from Punjab, Pakistan (Pryblski et al 1999) and Thailand (O'maera et al 2006) though quite less as compared to 10,000 parasites/μl was observed in Africa (Rogier et al 1996). Msp-3α was found to have two alleles A and B of which B was more prevalent and polymorphic contradicting previous studies from Iran (Zakeri et al 2006a, b), India and Pakistan (Khatoon et al 2010) where three alleles were observed with type A being the most prevalent.…”

Usefulness of clinical algorithm as screening process to detected malaria in low-to-moderate transmission areas of scarce health related resources

“…Also, P. falciparum was responsible for the majority of high parasitemic cases (Prybylski et al, 1999). These results are representative of moderate seasonal transmission of malaria, and different from results from other areas, e.g., the Sub-Saharan Africa, were transmission is much more extensive (McElroy et al, 1994;Rogier et al, 2005).…”

“…We anticipated that the score would vary according to the age of the patient and season of the year. Therefore, we tested the score in three subgroups of age (<6 years old, 6-14 years old, and >14 years old) and three subgroups of season: January-June: low malaria transmission; July-August: rainy season and high transmission for P. vivax, and September-December: high transmission season for P. falciparum (Prybylski et al, 1999). We also tested the score for those individuals presenting isolated infection due to P. falciparum and for high parasitemic P. falciparum individuals, and for isolated infection due to P. vivax.…”

“…Low and season exposure levels to malaria parasites create a different scenario in areas of lowto-moderate risk of malaria transmission. Clinical malaria occurs at all ages and at parasite densities well below those usually required to cause illness in the highly endemic Sub-Saharan Africa (McElroy et al, 1994;Beadle et al, 1995;Prybylski et al, 1999;Rogier et al, 2005). For that scenario, WHO recommends parasitic confirmation before treatment.…”

Prognostic value of clinical and parasitological signs for severe malaria in patients from Colombia

“…La hiperpirexia se ha considerado una característica de malaria complicada asociada con niveles elevados de factor de necrosis tumoral, interferón gamma, IL-6 e IL-10 (36), y se ha propuesto que la carga parasitaria se relaciona con este signo (37). En el presente estudio no se encontró esta asociación, aunque la mediana de la temperatura axilar fue significativamente superior (U de Mann-Whitney, p=0,020) en los pacientes con hiperparasitemia (38,5 ºC) que sin ésta (37,0 ºC).…”