How prevalent is Plasmodium malariae in Rondônia, Western Brazilian Amazon?

Cavasini, Marisa Torres Vidal; Ribeiro, Weber Luidi; Kawamoto, Fumihiko; Ferreira, Marcelo Urbano

doi:10.1590/s0037-86822000000500011

Cited by 56 publications

(66 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[14] and 9.4% in patient samples were detected by PCR [63]. As in PNG, the majority of infections were found in the presence of P. falciparum and/or P. vivax (Table 1).…”

Section: Improved Diagnosis Of P Malariae and P Ovale Infections Bymentioning

confidence: 99%

See 1 more Smart Citation

Plasmodium malariae and Plasmodium ovale – the ‘bashful’ malaria parasites

Müeller

Zimmerman

Reeder

2007

Trends in Parasitology

255

228

View full text Add to dashboard Cite

Although Plasmodium malariae was first described as an infectious disease of humans by Golgi in 1886 and Plasmodium ovale identified by Stevens in 1922, there are still large gaps in our knowledge of the importance of these infections as causes of malaria in different parts of the world. They have traditionally been thought of as mild illnesses that are caused by rare and, in case of P. ovale, short-lived parasites. However, recent advances in sensitive PCR diagnosis are causing a re-evaluation of this assumption. Low-level infection seems to be common across malaria-endemic areas, often as complex mixed infections. The potential interactions of P. malariae and P. ovale with Plasmodium falciparum and Plasmodium vivax might explain some basic questions of malaria epidemiology, and understanding these interactions could have an important influence on the deployment of interventions such as malaria vaccines. Geographical distributionAlthough distribution of Plasmodium malariae infection is reported as being patchy, it has been observed in all major malaria-endemic regions of the world [1]. P. malariae infections are most common in sub-Saharan Africa and the southwest Pacific, where age-specific prevalence in mass blood surveys have exceeded 15-30% [2][3][4][5][6][7][8]. By contrast, when P. malariae has been detected in malaria-endemic regions of Asia [9][10][11][12], the Middle East [13], South America [14] and Central America [15], it is observed as an infrequent infection, with blood-smear light microscopy (LM) prevalence rarely exceeding 1-2%. Much higher levels of infection were, however, found in montagnard refugees from the Cambodian-Vietnamese border [16]. In South America, P. malariae is thought to be a zoonotic infection because the genetically identical Plasmodium brasilianum infects new-world monkeys [17] and both monkeys and humans in endemic areas show high levels of seropositivity to P. malariae and P. brasilianum antigens [18].Plasmodium ovale was thought to have a much more limited distribution, with endemic transmission traditionally described as being limited to areas of tropical Africa, New Guinea, the eastern parts of Indonesia and the Philippines [19,20]. Infections with P. ovale, however, have also been reported in the Middle East [13], the Indian subcontinent [21] and different parts of Southeast Asia [11,22,23]. In West Africa (and to a lesser extent Central Africa), age specific LM prevalence of >10% have been observed [3,6] places where P. ovale is observed, it is relatively uncommon and its prevalence (as detected by LM) rarely exceeds 3-5% [22,[24][25][26].Indepth descriptions of the epidemiology of both infections based upon LM data are, thus, restricted almost exclusively to highly endemic areas in Africa and the Southwest Pacific. Detailed epidemiological studies from South America and Asia are lacking. Variation in parasite prevalenceIn West Africa, P. malariae prevalence has been reported to peak at ages similar to those of P. falciparum (i.e. in children under ten years of...

show abstract

“…[14] and 9.4% in patient samples were detected by PCR [63]. As in PNG, the majority of infections were found in the presence of P. falciparum and/or P. vivax (Table 1).…”

Section: Improved Diagnosis Of P Malariae and P Ovale Infections Bymentioning

confidence: 99%

“…This confirmed that both parasite species are common across much of the region. In the Brazilian Amazon, P. malariae prevalence of 11.9% in the general population[14] and 9.4% in patient samples were detected by PCR [63]. As in PNG, the majority of infections were found in the presence of P. falciparum and/or P. vivax (Table 1).…”

mentioning

confidence: 99%

Plasmodium malariae and Plasmodium ovale – the ‘bashful’ malaria parasites

Müeller

Zimmerman

Reeder

2007

Trends in Parasitology

255

228

View full text Add to dashboard Cite

show abstract

“…Laboratorial diagnoses, in general, are made using the thick and thin blood film techniques. However, induced morphologic alterations can occur during the staining of slides, modifying the data of these species 7 . Moreover, some parasitic development stages can lead to errors in diagnosis, even with extremely experienced microscopists.…”

Section: Discussionmentioning

confidence: 99%

“…Previous reports 4,7 have demonstrated the superiority of the molecular method to the thick blood film technique. However PCR could have its limitations including its high cost and the necessity of adequate equipment and trained technicians.…”

Section: Discussionmentioning

confidence: 99%

Molecular screening of Plasmodium sp. asymptomatic carriers among transfusion centers from Brazilian Amazon region

Fugikaha

Fornazari

Penhalbel

et al. 2007

Rev. Inst. Med. trop. S. Paulo

View full text Add to dashboard Cite

SUMMARYThe transmission of malaria in Brazil is heterogeneous throughout endemic areas and the presence of asymptomatic Plasmodium sp. carriers (APCs) in the Brazilian Amazon has already been demonstrated. Malaria screening in blood banks is based on the selection of donors in respect to possible risks associated with travel or residence, clinical evidence and/or inaccurate diagnostic methods thereby increasing the probability of transfusion-transmitted infection. We evaluated the frequency of APCs in four blood services in distinct areas of the Brazilian Amazon region. DNA was obtained from 400 human blood samples for testing using the phenol-chloroform method followed by a nested-PCR protocol with species-specific primers. The positivity rate varied from 1 to 3% of blood donors from the four areas with an average of 2.3%. All positive individuals had mixed infections for Plasmodium vivax and Plasmodium falciparum. No significant differences in the results were detected among these areas; the majority of cases originated from the transfusion centres of Porto Velho, Rondônia State and Macapá, Amapá State. Although it is still unclear whether APC individuals may act as reservoirs of the parasite, efficient screening of APCs and malaria patients in Brazilian blood services from endemic areas needs to be improved.

show abstract

“…the P. vivax infections were 'cryptic'). However, even if mixed infections in humans were underestimated, as shown recently [31,32], their proportions would remain extremely low [28]. Moreover, if P. vivax co-infections were to reduce P. falciparum infection pathology, as recently suggested [3,5], treatment would inadvertently focus on P. falciparum unispecies infections.…”

Section: The Brazilian Situationmentioning

confidence: 99%