Primary health care as assessed by health professionals: comparison of the traditional model versus the Family Health Strategy

<div><p>ABSTRACT: Introduction: The Family Health Strategy (FHS) should be first-contact care in the Brazilian Health System. However, Primary Health Care (PHC) still encompasses two models: the FHS and the traditional health care facilities. The expansion of the FHS has been slow and heterogeneous in many cities, rendering a comparative evaluation of key quality-related elements of PHC models crucial. Objective: To compare the performance of PHC models as perceived by health professionals. Methods: A cross-sectional study involving managers and health professionals from PHC of a medium-size city in South-eastern Brazil. Data were collected by applying the Primary Care Assessment Tool. The performance was estimated through primary health care indexes (general and partial PHCI by attributes). Univariate polytomous logistic regression was performed to compare care model performances according to their attributes. Strength of association was estimated by odds ratio with 95% confidence interval. Results: Three managers and 81 health professionals participated in the study. The FHS had a better index rating than the traditional care model for general PHCI and for the attributes longitudinality, comprehensiveness, family focus and professional level. Conclusion: Although the FHS attained higher scores compared to the traditional model, it has not yet achieved the performance expected. This scenario points to the need for increased FHS cover and quality improvements at the existing units.</p></div

Identification of Ab3 biomarker.

<p>(A) Scheme illustrating the two groups used to identify antibody biomarker(s) that could serve as parasite persistence indicator. Group A comprises untreated and treated PCR Pos patients because all of them contain circulating parasites. Group B includes treated PCR Neg patients because they have the highest likelihood of parasitological cure. (B) Algorithm for defining parasite persistence versus parasite clearance based on Ab3. High signal intensity of Ag3 are assessed with a score ≥ 2 indicating parasite persistence; low or negative Ag3 are evaluated with a score < 2 indicating parasite clearance.</p

Antigens map.

<p>(A) Antigens used in the assay and their respective position in the array are given together with the corresponding references. (B) Schematic representation of the fifteen antigens spotted in duplicate in a single well of a 96-well plate. (C) For the visual interpretation, the intensity of each antigen is compared to the range spots (cut-off and medium spot) and the intensity is scored as follows: 0, absent or less intense than a visible spot; 0.5, intensity between that of the visible spot and that of the cut-off spot; 1, intensity between the cut-off spot and that of the medium spot; 2, intensity equal to that of the medium spot; 3, intensity higher than that of the medium spot.</p

Serological profiles.

<p>Representative examples of serological profiles among each subgroup of the SaMi-Trop cohort. The black rectangle indicates Ag3. Ag3 reactivity’s in parasite persistence patients are high and low or absent in patients with cleared parasites.</p

Box plots illustrating antibody response diversity.

<p>Box plots indicating the number of reactive antigens in function of Ab3 scores. We note that high scores (Ab3 ≥ 2) samples display large number of antigen reactivities as opposed to low scores (Ab3 < 2).</p

Reactivity of each antigen with seropositive samples according to different criteria (PCR and treatment).

<p>A sample is considered reactive on a given antigen if the score is superior to 0.</p

Distribution of Ab3 scores among each subgroup of the SaMi-Trop cohort.

<p>Distribution of Ab3 scores among each subgroup of the SaMi-Trop cohort.</p

A novel antibody surrogate biomarker to monitor parasite persistence in <i>Trypanosoma cruzi</i>-infected patients

<div><p>Background</p><p><i>Trypanosoma cruzi</i> parasite, the causative agent of Chagas disease, infects about six million individuals in more than 20 countries. Monitoring parasite persistence in infected individuals is of utmost importance to develop and evaluate treatments to control the disease. Routine screening for infected human individuals is achieved by serological assays; PCR testing to monitor spontaneous or therapy-induced parasitological cure has limitations due to the low and fluctuating parasitic load in circulating blood. The aim of the present study is to evaluate a newly developed antibody profiling assay as an indirect method to assess parasite persistence based on waning of antibodies following spontaneous or therapy-induced clearance of the infection.</p><p>Methodology/Principal findings</p><p>We designed a multiplex serology assay, an array of fifteen optimized <i>T</i>. <i>cruzi</i> antigens, to evaluate antibody diversity in 1654 serum samples from chronic Chagas patients. One specific antibody response (antibody 3, Ab3) showed a strong correlation with <i>T</i>. <i>cruzi</i> parasite persistence as determined by <i>T</i>. <i>cruzi</i> PCR positive results. High and sustained Ab3 signal was strongly associated with PCR positivity in untreated patients, whereas significant decline in Ab3 signals was observed in BZN-treated patients who cleared parasitemia based on blood PCR results.</p><p>Conclusion/Significance</p><p>Ab3 is a new surrogate biomarker that strongly correlates with parasite persistence in chronic and benznidazole-treated Chagas patients. We hypothesize that Ab3 is induced and maintained by incessant stimulation of the immune system by tissue-based and shed parasites that are not consistently detectable by blood based PCR techniques. Hence, a simple immunoassay measurement of Ab3 could be beneficial for monitoring the infectious status of seropositive patients.</p></div

Ab3 is a surrogate marker to monitor parasite persistence.

<p>Distribution of subgroups parasite persistence and clearance in percentage in each subgroup of the SaMi-Trop cohort. When a score ≥ 2 is assigned to Ab3 serology, the patient is considered as having a persisting parasites (in red). If the Ab3 scores < 2 (signals below the cutoff) the patient has putatively cleared the parasite (in blue). Ab3 high scoring serology classifies about 90% of the patients to the parasite persistence group in both PCR Pos groups which contain circulating <i>T</i>. <i>cruzi</i> parasites.</p

Area under the curves (AUC) of each individual antigen showing separation power between the two analyzed groups A & B.

<p>Area under the curves (AUC) of each individual antigen showing separation power between the two analyzed groups A & B.</p