High prevalence of Plamodium malariae infections in a Brazilian Amazon endemic area (Apiacás—Mato Grosso State) as detected by polymerase chain reaction

Scopel, Kézia Katiani Gorza; Fontes, Cor Jésus Fernandes; Nunes, Álvaro Cantini; Horta, Maria Fátima; Braga, Érika Martins

doi:10.1016/j.actatropica.2003.11.002

Cited by 68 publications

(82 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…darlingi in the earlier study in Boa Vista (Silva-Vasconcelos et al 2002) but ELISA slightly underestimates the overall prevalence of malaria parasites in anophelines because it is not as sensitive as ELISA-PCR (Póvoa et al 2000a). Thick blood smears also underestimate the prevalence of P. malariae in humans (Scopel et al 2004). These findings suggest that accurate diagnosis of P. malariae should be a higher priority because this parasite results in low, but significant levels of morbidity in humans (Collins et al 2004), there has been a recent resurgence in human cases in Pará (Póvoa et al 2003) as well as in Suriname (PAHO 2002) and misdiagnosis may mean that the wrong antimalarial treatment is given (Scopel et al 2004).…”

Section: Discussionmentioning

confidence: 99%

The importance of Anopheles albitarsis E and An. darlingi in human malaria transmission in Boa Vista, state of Roraima, Brazil

Póvoa

Souza

Lacerda

et al. 2006

Mem. Inst. Oswaldo Cruz

View full text Add to dashboard Cite

In several districts of Boa Vista, state of Roraima, Brazil we found Anopheles (Nyssorhynchus) albitarsis E to be the primary vector of human malaria parasites, and during 2001-2002 it was significantly more abundant than An. darlingi (p < 0.001). Other species sampled were An. (Nys.) braziliensis, An. (Ano.) peryassui, An. (Nys.) nuneztovari, An. (Nys.) oswaldoi s.l., and An. (Nys.) triannulatus. As determined by the ELISA technique An. darlingi had a higher overall infection rate (2.1%) compared with An. albitarsis E (1.2%). However, a marginally higher proportion of An. albitarsis E was infected with Plasmodium vivax compared with An. darlingi, and the An. albitarsis E biting index was also much higher. These results suggest the importance of An. albitarsis E in malaria transmission in a savannah ecoregion of northern Amazonian Brazil, and reconfirm the importance of An. darlingi even if at lower abundance

show abstract

Section: Discussionmentioning

confidence: 99%

The importance of Anopheles albitarsis E and An. darlingi in human malaria transmission in Boa Vista, state of Roraima, Brazil

Póvoa

Souza

Lacerda

et al. 2006

Mem. Inst. Oswaldo Cruz

View full text Add to dashboard Cite

show abstract

“…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).…”

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

confidence: 97%

“…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].…”

mentioning

confidence: 99%

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

Müeller

Zimmerman

Reeder

2007

Trends in Parasitology

270

245

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

“…Moreover, some parasitic development stages can lead to errors in diagnosis, even with extremely experienced microscopists. Microscopic diagnoses failed to detect low parasitemia in PCR-positive asymptomatic individuals living in endemic regions of Brazil 17 . The deficiency in the detection of mixed infections by the thin and thick blood film methods make treatment difficult as it is species-specific.…”

Section: Discussionmentioning

confidence: 99%

“…According to authors, native populations can act as a reservoir for the spread of malaria to migrants. In another study, conducted in a Mato Grosso State population, 32% of tested individuals were proved to be asymptomatic with P. malariae (single or mixed infections) within seventy-two hours after blood collection 17 . In the Amazonas State, 0.3% of blood donors evaluated in blood services presented with specific PCR-positivity for Plasmodium vivax 19 .…”

Section: Introductionmentioning

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

High prevalence of Plamodium malariae infections in a Brazilian Amazon endemic area (Apiacás—Mato Grosso State) as detected by polymerase chain reaction

Cited by 68 publications

References 5 publications

The importance of Anopheles albitarsis E and An. darlingi in human malaria transmission in Boa Vista, state of Roraima, Brazil

The importance of Anopheles albitarsis E and An. darlingi in human malaria transmission in Boa Vista, state of Roraima, Brazil

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

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

Contact Info

Product

Resources

About