Plasmodium malariae and Plasmodium ovale
Eric S. Loker, Bruce V. Hofkin in Parasitology, 2015
Pathology Infections caused by P. malariae and P. ovale are much less severe than for P. vivax and especially P. falciparum. Tertian malaria caused by P. ovale, like that caused by P. vivax, results in fever paroxysms every 48 hours, corresponding to the rupture of infected erythrocytes and the release of merozoites. Furthermore, sporozoites infecting liver cells do not necessarily undergo schizogony but may form hypnozoites, which may result in a relapse of disease up to 20 months after the initial infection. The slower growing P. malariae causes disease with paroxysms every 72 hours, known as quartan malaria. Although it does not enter a latent, hypnozoite stage, P. malariae can persist at low, subclinical levels for many years in infected individuals, who serve as reservoirs. It can later reach clinical significance again, a phenomenon known as recrudescence.
Inflammatory, Hypersensitivity and Immune Lung Diseases, including Parasitic Diseases.
Fred W Wright in Radiology of the Chest and Related Conditions, 2022
In the U.K. the number of cases fell from about 50,000 per annum in 1960 to about 6,500 ten years ago, but recently the number has again been increasing and London now (in 1999) has 2,700 active cases, and 50 new cases each week. In Oxford about equal numbers present from the native (white) population as do immigrants (mainly from the Indian subcontinent and West Indies), which means that the incidence in the latter is larger. Whilst a few of the native population presenting with tuberculosis are young (e.g. medical students returning from 'electives' in the 'third world'), most are older and have a recrudescence of previous infection, in many cases as a complication of other debilitating disease such as malignancy (bronchial neoplasm, etc.), diabetes (see also p. 17.8) or immuno-suppression. Some are alcoholics or live in poor conditions, a few are tramps, whilst others the author has seen have been 'dons' (Oxford University tutors). Some have had underlying disease, diabetes, AIDS (see ps. 19.18 & 23 - 24), etc.
Toxoplasma gondii
Peter D. Walzer, Robert M. Genta in Parasitic Infections in the Compromised Host, 2020
It is difficult to discern in Hodgkin's disease or other immunocompromising illnesses which mode of pathogenesis, new acute infection or recrudescence, is more prominent. Certain patients with severe disseminated toxoplasmosis have no detectable anti-Toxoplasma antibody at the time of diagnosis of toxoplasmic encephalitis, suggesting the acute onset of infection (11,300-302). In addition, the relationship of the onset of severe toxoplasma infection to the duration of the underlying malignancy varied from 2 months to 8 years, and in some instances occurred when the patient was not receiving chemotherapy and was in remission (12,303). In one patient with acute myelocytic leukemia, the patient seroconverted and developed severe toxoplasmic encephalitis while in remission. The acute acquisition of toxoplasma infection was also dramatically shown in four patients with acute leukemia who received granulocyte transfusions from two patients with chronic myelogenous leukemia. All four patients developed serological and clinical evidence of acute toxoplasma infection (26).
Receptor expression by JEG-3 trophoblast cells in the presence of placenta secreted factors
Published in Gynecological Endocrinology, 2019
Dmitry O. Bazhenov, Kseniya N. Furaeva, Olga I. Stepanova, Larisa P. Viazmina, Anastasiya R. Sheveleva, Evgeniya V. Khokhlova, Valentina A. Mikhailova, Sergey A. Selkov, Dmitry I. Sokolov
The placentas were either those obtained through artificial abortion from women on the 9th/11th week of physiological pregnancy (n = 19, group 1); or those on 38th and 39th weeks of normal pregnancy (n = 32, group2) after cesarean delivery before the labor start. Patients with type I and II diabetes mellitus, multiple pregnancies, polyhydramnios, urinary tract infection, acute infection or recrudescence of chronic infection, chronic kidney disease, chronic hypertension, and other cardiovascular diseases were excluded. All pregnant women were matched for age (31.6 ± 4.2 years), parity and obstetric history. All participants were Caucasian raсe coming from The North-West region of Russia. Preeclampsia was defined as pregnancy-induced hypertension (blood pressure ≥ 140/90 mm Hg), proteinuria (300 mg/24 h), and edema in the second half of pregnancy in women who were normotensive before pregnancy and had no underlying clinical problems such as renal disease.
Dietary Fiber and Human Papillomavirus Infection among US Women: The National Health and Nutrition Examination Survey, 2003–2016
Published in Nutrition and Cancer, 2021
Yingxuan Zhang, Fangfang Zhu, Chi Chen, Si Chen, Xian Huang, Yanxi Wang, Pin Qiu, Gaopi Deng, Jie Gao
This study has some weaknesses. First, due to the limitation of cross-sectional design, it was impossible to estimate the causal relationship between intake of dietary fiber and the risk of HPV infections, thus the results in our study are relatively weak. However, this study provides a new perspective for the etiology and prevention of HPV infection and helps to provide direction for subsequent mechanism research. Furthermore, large prospective cohort studies should be encouraged. Second, our data are extracted from NHANES database, which lacks information on history of cervical cancer and CIN and treatment of HPV infection. It limited us to determine whether the observed positivity represented recent, persistence, or recrudescence of infection. Third, the participants in our study were predominantly women in the US, the findings might not apply to men and women outside the US. Fourth, there are many metabolites of dietary fiber, it is impossible to determine which component works for our study, and further mechanistic research is needed. Fifth, there may be missing differences in the NHANES database, only variables in the NHANES database can be adjusted. Finally, although we adjusted several known potential factors that affect HPV infection, there might exist unobserved confounders that influence the research as with all observational studies.
Asymptomatic malaria in the clinical and public health context
Published in Expert Review of Anti-infective Therapy, 2019
James Cheaveau, Daniel Castaneda Mogollon, Md Abu Naser Mohon, Lemu Golassa, Delenasaw Yewhalaw, Dylan R Pillai
With the global malaria program again targeting malaria elimination [2,7,9], it has become even more important to understand what happens to asymptomatic malaria infections. Depending on the setting, asymptomatic infections are much more common than symptomatic infections and persist for a longer period of time. Individuals who are symptomatic seek treatment to curtail their infection, whereas asymptomatic individuals are obviously not driven by the infection to seek treatment (Figure 3). A study in Ghana of asymptomatic P. falciparum infections detected by PCR found that 21% of infections terminated within 1 week, whereas others persisted for up to a maximum of 179 days [95]. Another longitudinal study in Vietnam found that 20% of participants with P. falciparum had infections persisting for greater than 4 months and 9% of participants with P. vivax had infections persisting for the same period [96]. This is particularly relevant to onwards transmission, where individuals with persisting infections will be exposed to a greater number of mosquito bites than symptomatic individuals who seek treatment. Additionally, in the study by Nguyen et al., parasitemias oscillated with some eventually producing high-density infections, but this study did not genotype infections meaning that is was difficult to differentiate between persisting infection (recrudescence) and re-infection [96]. Other studies have suggested that asymptomatic infections rarely progress to symptomatic infections, and 92% of subsequent symptomatic malarial episodes in this setting are due to new infections with a different genotype, which have not been prevented due to immunity [97].
Related Knowledge Centers
- Bovine Viral Diarrhea
- Malaria
- Plasmodium Falciparum
- Signs & Symptoms
- Relapse
- Plasmodium Vivax
- Plasmodium Ovale
- Plasmodium Malariae
- Plasmodium Knowlesi
- Melioidosis