Use Of Chloroquine Research Articles

Caution and clarity required in the use of chloroquine for COVID-19.

As the coronavirus disease 2019 (COVID-19) outbreak continues to spread rapidly, efforts are ongoing in China and around the world to develop effective treatments. Among the drugs being tested for COVID-19 in China is chloroquine, which was reported on Feb 4, 2020, to inhibit severe acute respiratory syndrome coronavirus 2 in vitro. The drug was rapidly pushed to clinical testing as an experimental treatment in China; on Feb 15, 2020, it was included in the sixth version of the COVID-19 treatment guidelines by the National Health Commission of the People's Republic of China.

Rapamycin does not reproduce the alterations to Caco‐2 transepithelial electrical resistance caused by the knockdown of Raptor

Intestinal homeostasis is achieved through well‐coordinated interactions between the mucus layer, the epithelial layer and the immune cells of the lamina propria. Owing to its proximity with the luminal content, the intestinal epithelium is exposed to insults of chemical, physical or dysbiotic nature. These insults may perturb the epithelium permeability and trigger a localized immune response, which if not controlled may progress to damage the epithelium. Although the mechanistic target of rapamycin complex 1 (mTORC1) is deactivated in differentiated enterocytes, mTORC1 becomes active under repeated insult or injury to the epithelium and participates in epithelial cell repair. However, many aspects of mTORC1 re‐activation remain to be elucidated. To investigate the effects of graded levels of mTORC1 activity on epithelial barrier function, we knocked down (>90% down) mTORC1 signaling‐associated proteins, Raptor and TSC2, to create three Caco‐2 cell lines in which, after full differentiation in Transwell®, mTORC1 activity was either normal (shScramble cells), low (shRaptor cells, mTORC1 activity 50% lower than shScramble cells) or high (shTSC2 cells, mTORC1 activity 80% higher than shScramble cells). When compared with shScramble cells, shRaptor cells had higher abundance of p‐(Thr172)AMPK (+46%, P<0.05), lower abundance of p‐(Ser757)ULK‐1 (−50%, P>0.05), higher autophagic flux (+180%, P<0.05), and lower expression of pore‐forming tight junction protein Claudin‐2 (−65%, P<0.05). In contrast, shTSC2 cells had higher levels of p‐(Ser757)ULK‐1 (+100%, P<0.05) and Claudin‐2 (+250%, P<0.05) compared with shScramble cells. These mTORC1‐related changes were accompanied by significant alteration to the Caco‐2 transepithelial electrical resistance (TEER), which was 180% higher in shRaptor cells vs. shScramble cells, and conversely 60% lower in shTSC2 cells vs. shScramble cells. Although rapamycin suppressed mTORC1 activity in these cells, rapamycin caused a modest 34% (P<0.05) increase of TEER in shScramble cells, suggesting that factors other than mTORC1 ablation were responsible for the high TEER of shRaptor cells. The use of chloroquine (an inhibitor of autophagosome‐lysosome fusion) showed that autophagy alone could not explain the strong electrical resistance of shRaptor cells. We are currently investigating whether TSC2, whose expression increases as Caco‐2 cells differentiate concomitantly with mTORC1 silencing, might regulate paracellular permeability and tight junction assembly in the epithelium.Support or Funding InformationUSDA‐NIFA

Is it worth the wait? Should Chloroquine or Hydroxychloroquine be allowed for immediate use in CoViD-19?

<span lang="EN-MY" style="font-family:&quot;Times New Roman&quot;,serif"><p style="text-align:justify;text-justify:inter-ideograph;line-height:150%"> <p style="text-align:justify;text-justify:inter-ideograph;line-height:150%"><span lang="EN-MY" style="font-family:&quot;Times New Roman&quot;,serif">The growing CoViD-19 (novel coronavirus disease 2019) pandemic and the number of deaths is becoming a big concern across the world. There is a need for an immediate therapeutic solution to prevent the spread of the disease further and prevent the number of CoViD-19 associated deaths across the world. The healthcare professionals and the public at large are asking questions about the evidence surrounding the use of chloroquine (CQ) and hydroxychloroquine (HCQ) in the management of CoViD-19. Both CQ and HCQ had been recently used clinically across the world to treat severe pneumonia associated with COViD-19, however, the evidence is very weak due to the lack of randomised clinical trials and misinterpretation of clinical evidence by the non-scientific community. This article presents a critical review of clinical and scientific evidence around the use of CQ and HCQ in CoViD-19 available to date and highlighted the issues concerning the safety and toxicity of CQ/HCQ if permitted for general use by the public. Due to lack of evidence around CQ/HCQ in preventing the CoViD-19, its potential risk of fatal cardiac arrhythmia, and greater risk of self-use and harm in the developing world, it is recommended that the use of CQ/HCQ should only be initiated by specialist clinician dealing with CoViD-19 outbreak to treat CoViD-19 associated pneumonia under close cardiac monitoring.</span> <p style="text-align:justify;text-justify:inter-ideograph;line-height:150%"> </span>

Hydroxychloroquine and chloroquine for COVID-19 infection. Rapid systematic review

CONTEXT: Based on the results of preliminary studies, the off-label use of hydroxychloroquine for COVID-19 infection has been observed in practice. OBJECTIVES: To identify, systematically assess and summarize the best available evidence on the efficacy and safety of the use of hydroxychloroquine and chloroquine for COVID-19 infection. METHODS: Rapid systematic review. RESULTS: After the selection process, 30 studies were included: one open-label randomized trial, one open-label non-randomized trial and 28 ongoing studies. The outcome 'detection of viral load in oral swab' (surrogate outcome) was evaluated by both studies, involving a total of 72 participants. The findings of the studies were discordant: one study observed a higher frequency of negative viral load associated with hydroxychloroquine on day-7, while the other study did not observe any difference between hydroxychloroquine and the control group (standard treatment) on day-6. Both studies have methodological limitations when evaluated by specific tools according to study design (Cochrane Bias Risk Table and ROBINS-I). CONCLUSION: This rapid systematic review identified two clinical studies (with available data), with limited methodological quality, that evaluated the effects of hydroxychloroquine for COVID-19 infection. Based on the findings of these two studies, the efficacy and safety of hydroxychloroquine and chloroquine in patients with COVID-19 is still uncertain (very low evidence certainty) and its routine use for this situation should not be recommended until the results of ongoing studies could provide a proper assessment of their effects.

COVID-19 Outbreak and Perspective in Morocco

Coronavirus disease 2019 (COVID-19) is a respiratory illness that can spread from person to person. The virus that causes COVID-19 is a novel coronavirus that was first identified during an investigation into an outbreak in Wuhan, China and rapidly spread across the world to become the first pandemic caused by a coronavirus. As of 26 March 2020, there are 275 cases affected by COVID-19 announced by the Moroccan government, and it possible to limit the spread of this serious disease, with the cooperation of all the citizens in respect of the measures of containment and individual protection. Also, with the announce yesterday by the Moroccan government of the authorization of use of chloroquine in treatment of COVID-19 pneumonia, COVID-19 will be soon eradicated from Morocco and hopefully from all over the world

Coronavirus disease 2019 (COVID-19) pandemic and pregnancy

The current coronavirus disease 2019 (COVID-19) pneumonia pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is spreading globally at an accelerated rate, with a basic reproduction number (R0) of 2–2.5, indicating that 2–3 persons will be infected from an index patient. A serious public health emergency, it is particularly deadly in vulnerable populations and communities in which healthcare providers are insufficiently prepared to manage the infection. As of March 16, 2020, there are more than 180,000 confirmed cases of COVID-19 worldwide, with more than 7000 related deaths. The SARS-CoV-2 virus has been isolated from asymptomatic individuals, and affected patients continue to be infectious 2 weeks after cessation of symptoms. The substantial morbidity and socioeconomic impact have necessitated drastic measures across all continents, including nationwide lockdowns and border closures.Pregnant women and their fetuses represent a high-risk population during infectious disease outbreaks. To date, the outcomes of 55 pregnant women infected with COVID-19 and 46 neonates have been reported in the literature, with no definite evidence of vertical transmission. Physiological and mechanical changes in pregnancy increase susceptibility to infections in general, particularly when the cardiorespiratory system is affected, and encourage rapid progression to respiratory failure in the gravida. Furthermore, the pregnancy bias toward T-helper 2 (Th2) system dominance, which protects the fetus, leaves the mother vulnerable to viral infections, which are more effectively contained by the Th1 system. These unique challenges mandate an integrated approach to pregnancies affected by SARS-CoV-2.Here we present a review of COVID-19 in pregnancy, bringing together the various factors integral to the understanding of pathophysiology and susceptibility, diagnostic challenges with real-time reverse transcription polymerase chain reaction (RT-PCR) assays, therapeutic controversies, intrauterine transmission, and maternal−fetal complications. We discuss the latest options in antiviral therapy and vaccine development, including the novel use of chloroquine in the management of COVID-19. Fetal surveillance, in view of the predisposition to growth restriction and special considerations during labor and delivery, is addressed. In addition, we focus on keeping frontline obstetric care providers safe while continuing to provide essential services. Our clinical service model is built around the principles of workplace segregation, responsible social distancing, containment of cross-infection to healthcare providers, judicious use of personal protective equipment, and telemedicine. Our aim is to share a framework that can be adopted by tertiary maternity units managing pregnant women in the flux of a pandemic while maintaining the safety of the patient and healthcare provider at its core.

Expert consensus on chloroquine phosphate for the treatment of novel coronavirus pneumonia

At the end of December 2019, a novel coronavirus (COVID-19) caused an outbreak in Wuhan, and has quickly spread to all provinces in China and 26 other countries around the world, leading to a serious situation for epidemic prevention. So far, there is still no specific medicine. Previous studies have shown that chloroquine phosphate (chloroquine) had a wide range of antiviral effects, including anti-coronavirus. Here we found that treating the patients diagnosed as novel coronavirus pneumonia with chloroquine might improve the success rate of treatment, shorten hospital stay and improve patient outcome. In order to guide and regulate the use of chloroquine in patients with novel coronavirus pneumonia, the multicenter collaboration group of Department of Science and Technology of Guangdong Province and Health Commission of Guangdong Province for chloroquine in the treatment of novel coronavirus pneumonia developed this expert consensus after extensive discussion. It recommended chloroquine phosphate tablet, 500mg twice per day for 10 days for patients diagnosed as mild, moderate and severe cases of novel coronavirus pneumonia and without contraindications to chloroquine.

A systematic review on the efficacy and safety of chloroquine for the treatment of COVID-19.

PurposeCOVID-19 (coronavirus disease 2019) is a public health emergency of international concern. As of this time, there is no known effective pharmaceutical treatment, although it is much needed for patient contracting the severe form of the disease. The aim of this systematic review was to summarize the evidence regarding chloroquine for the treatment of COVID-19.MethodsPubMed, EMBASE, and three trial Registries were searched for studies on the use of chloroquine in patients with COVID-19.ResultsWe included six articles (one narrative letter, one in-vitro study, one editorial, expert consensus paper, two national guideline documents) and 23 ongoing clinical trials in China. Chloroquine seems to be effective in limiting the replication of SARS-CoV-2 (virus causing COVID-19) in vitro.ConclusionsThere is rationale, pre-clinical evidence of effectiveness and evidence of safety from long-time clinical use for other indications to justify clinical research on chloroquine in patients with COVID-19. However, clinical use should either adhere to the Monitored Emergency Use of Unregistered Interventions (MEURI) framework or be ethically approved as a trial as stated by the World Health Organization. Safety data and data from high-quality clinical trials are urgently needed.

Expert consensus on chloroquine phosphate for the treatment of novel coronavirus pneumonia

At the end of December 2019, a novel coronavirus (COVID-19) caused an outbreak in Wuhan, and has quickly spread to all provinces in China and 26 other countries around the world, leading to a serious situation for epidemic prevention. So far, there is still no specific medicine. Previous studies have shown that chloroquine phosphate (chloroquine) had a wide range of antiviral effects, including anti-coronavirus. Here we found that treating the patients diagnosed as novel coronavirus pneumonia with chloroquine might improve the success rate of treatment, shorten hospital stay and improve patient outcome. In order to guide and regulate the use of chloroquine in patients with novel coronavirus pneumonia, the multicenter collaboration group of Department of Science and Technology of Guangdong Province and Health Commission of Guangdong Province for chloroquine in the treatment of novel coronavirus pneumonia developed this expert consensus after extensive discussion. It recommended chloroquine phosphate tablet, 500mg twice per day for 10 days for patients diagnosed as mild, moderate and severe cases of novel coronavirus pneumonia and without contraindications to chloroquine.

Pengobatan antimalaria klorokuin sebagai terapi penyakit Systemic Lupus Erythematosus (SLE)

Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease that attacks various organs. Antimalarial agents are part of an immunomodulatory regimen that is used to cure patients with SLE. Not all antimalarial agents can be used in the treatment of lupus; This review lends to the study of the use of chloroquine. Overall, antimalarial drugs have many beneficial effects in patients with SLE, and have a good safety profile. According to the American College of Rheumatology (ACR) the diagnosis of SLE was originally established to be found at least 2 or more than 11 criteria. The classification degrees are divided into mild, moderate and severe SLE. The recommended use of base chloroquine 3.5-4.0 mg / kg BW / day (150-300 mg / day) is only used in mild SLE.

Chloroquine and Hydroxychloroquine in Treatment of COVID-19 Disease

The use of chloroquine and its derivatives as an anti-viral agent is supported by pre-clinical in-vitro studies and its clinical safety is known in the term of its other indications. But there is insufficient clinical data to support its use in critically ill patients with The noval corona virus disease 2019 (COVID-19). Nevertheless, it is recommended that these drugs, which are supported by the urgency of the COVID-19 pandemic in many national guidelines and consensus reports, including our country, should be applied in accordance with the guidelines.

COVID-19 Outbreak: How to Use Current Knowledge to better Treat Positive Patients

COVID-19 Outbreak: How to Use Current Knowledge to better Treat Positive Patients

Potential specific therapies in COVID-19.

COVID-19 has grown into a global pandemic that has strained healthcare throughout the world. There is a sense of urgency in finding a cure for this deadly virus. In this study, we reviewed the empiric options used in common practice for COVID-19, based on the literature available online, with an emphasis on human experiences with these treatments on severe acute respiratory syndrome-associated coronavirus (SARS-COV-1) and other viruses. Convalescent blood products are the most promising potential treatment for use in COVID-19. The use of chloroquine or hydroxychloroquine (HCQ), remdesivir, and tocilizumab are some of the other promising potential therapies; however, they are yet to be tested in randomized clinical trials (RCTs). The use of lopinavir-ritonavir did not prove beneficial in a large RCT. The use of corticosteroids should be avoided in COVID-19 pneumonia unless used for other indications, based on the suggestion of harm in patients with SARS-COV-1 and Middle Eastern Respiratory Syndrome (MERS) infection. The reviews of this paper are available via the supplemental material section.

Chloroquine and hydroxychloroquine as a repurposed agent against COVID-19: a narrative review

The predicament arising from the coronavirus disease 2019 (COVID-19) pandemic has become one of the most significant modern public health challenges. Despite uncertainties in the viral determinants and pathogenesis, it is crucial to accurately inspect all available evidence to construct accurate clinical guidelines for optimised patient care. This study aims to discuss the available evidence for the use of chloroquine (CQ) and hydroxychloroquine (HCQ) against COVID-19. Early in vitro studies of CQ/HCQ against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are convincing. But contradictory evidence exists on the clinical use of CQ/HCQ, either alone or in combination with azithromycin. As of now, there is no compelling clinical evidence on CQ, HCQ, and azithromycin in COVID-19 and the available evidence is limited to methodologically inferior non-randomised studies. Studies have also shown detrimental drug reactions to CQ and ‘HCQ plus azithromycin’, mainly cardiac side effects in hospitalised patients with coexisting cardiovascular comorbidities. Therefore, we recommend that physicians avoid high doses and exercise extreme caution in the compassionate use of CQ/HCQ, either alone or in combination with other antiviral drugs.

Dosadašnja saznanja o etiopatogenezi i mogućnostima terapije Kovid-19

Currently, over 35 million people in the world are infected with the COVID-19 and over a million have died. The pandemic character of the disease has imposed dynamic research both in the field of clarification of the etiopathogenetic mechanisms of the disease and in the field of possible therapy. The amount of scientific knowledge has increased dozens of times in the last nine months, but we are still not even close to define an effective and safe therapy. The knowledge that COVID-19 is not only a respiratory but also a multisystem disease, which affects almost all organs, gave us opportunities for therapeutic adjustments. Strong oxidative stress, silent chronic hypoxia, increased coagulability, and increased platelet aggregation are just some of the mechanisms in the development of the disease. Cardiovascular consequences and vascular endothelial dysfunction are thought to be mainly responsible for death with a dangerous cytokine storm and acute respiratory distress syndrome. Having all this in mind in the therapeutic sense, it is proposed to use antibiotics, high doses of vitamin C, blood transfusion, immunoglobulin, interferon, anti-IL-6 antibodies, small doses of Dexamethasone or other corticosteroids, specific antiviral drugs such as favipiravir and remdesivir. The use of chloroquine is excluded from the therapeutic protocols of the World Health Organization and the Centers for Disease Control and Prevention (United States of America). For preventive and supportive purposes, high doses of vitamin D, vitamin C, zinc, probiotics, Alpha-lipoic acid, and other supplements are recommended. The use of anti-inflammatory, analgo-antipyretics drugs is considered justified, as well as the use of small doses of acetylsalicylic acid. Over 70 other drugs are currently being tested in over 400 clinical studies. In patients who already use corticosteroids by inhalation or intranasally due to asthma, chronic obstructive pulmonary disease, allergic rhinitis, or biological drugs due to immunomodulatory inflammatory diseases, this therapy should not be changed and it is not a prerequisite condition for more severe forms of the disease. The specifics of the infection in special populations such as children or pregnant women must also be taken into consideration.

Tratamento precoce para COVID-19 baseado em evidência científica

Objective: To present a proposal for early treatment of patients with COVID-19 in a Primary Health Care (PHC) center. Methods: This is a proposed treatment protocol for COVID-19 using hydroxychloroquine or chloroquine based on the currently (June 13, 2020) available scientific literature. PubMed database was searched for studies using the descriptors COVID-19, hydroxychloroquine, and chloroquine. Five studies were selected from the 645 studies found as they addressed the use of hydroxychloroquine or chloroquine in the treatment of COVID-19 in early stages. Results: The proposed early treatment protocol for patients with suspected COVID-19 includes guidance on the main symptoms, general guidelines for the population, medical evaluation, examination considerations, recommended therapy, post-prescription guidelines and criteria for hospitalization. Conclusion: According to the studies, early outpatient treatment of COVID-19 with hydroxychloroquine or chloroquine seems to decrease the risk of hospitalization and the need for intensive care beds. The decision to adopt the proposed treatment is made by the patient, and the physician should only conduct the treatment after obtaining written informed consent from the patient, as it is an off-label prescription. Randomized studies are needed to confirm this hypothesis.

A Review of the Current State of Management and Post-Recovery Rehabilitation of COVID-19

In all countries, COVID-19 has had a profound impact on society in general and on healthcare systems in particular. Its route of transmission is similar to that of SARS-CoV and MERS-CoV, and it spreads through respiratory droplets and direct physical contact. It displays greater infectivity rates than the two recent viral outbreaks (SARS and MERS), and early epidemiological studies reveal lower fatality rates. Elderly and multimorbid persons are at the highest risk of developing complications and death. Although men and women are thought to be at equal risk for COVID-19, more men than women are dying, presumably due to sex-based immunological differences and lifestyle factors such as smoking. N95 respirators are thought to be more effective in preventing viral transmission than surgical masks, but the evidence is limited and inconsistent. The current clinical management strategy of COVID-19 is the same as acute respiratory distress syndrome (ARDS). Novel treatments and therapies such as the use of plasmapheresis, chloroquine, hydroxychloroquine, and remdesivir have shown promising results in clinical trials for treating COVID-19. The roles of physical rehabilitation and medicine are expected to increase because postrecovery COVID-19 patients are experiencing cardiovascular, neurological, psychological, and cognitive sequalae. Innovative management strategies are needed to limit the spread of disease and to protect vulnerable persons. Significant evidence indicates that the use of telerehabilitation reduces hospitalizations and cardiac events compared to regular care. Actions are needed to prevent deconditioning in rehabilitation patients, and respiratory therapy practices will require close attention to reduce the dispersion of air droplets.

Tubeimoside-I sensitizes colorectal cancer cells to chemotherapy by inducing ROS-mediated impaired autophagolysosomes accumulation

BackgroundTubeimoside-I (TBM), a plant-derived bioactive compound, shows antitumor activity in different tumors and can enhance the efficacy of chemotherapeutic agents. However, the detail mechanism underlying remains to be elucidated.MethodsThe cytotoxic potential of TBM towards CRC cells was examined by CCK8 assay, colony formation, LDH release assay, flow cytometry method and Western blots. The ROS levels, autophagy, apoptosis, chemosensitivity to 5-FU or DOX, etc. were determined between control and TBM-treated CRC cells.ResultsIn this study, we found that TBM could inhibit proliferation and induce apoptosis in colorectal cancer (CRC) cells. Intriguingly, TBM treatment could either promote autophagy initiation by ROS-induced AMPK activation, or block autophagy flux through inhibiting lysosomal hydrolytic enzymes, which leaded to massive impaired autophagylysosomes accumulation. Administration of autophagy initiation inhibitor (3-MA or selective ablation of autophagy related proteins) relieves TBM-induced CRC suppression, while combination use of autophagy flux inhibitor chloroquine (CQ) slightly augments TBM-induced cell death, suggesting that impaired autophagylysosomes accumulation contributes to TBM-induced growth inhibition in CRC cells. Notably, as an autophagy flux inhibitor, TBM works synergistically with 5-fluorouracil (5-FU) or doxorubicin (DOX) in CRC suppression.ConclusionTogether, our study provides new insights regarding the anti-tumor activity of TBM against CRC, and established potential applications of TBM for CRC combination therapies in clinic.

Persistence of chloroquine resistance alleles in malaria endemic countries: a systematic review of burden and risk factors

BackgroundChloroquine, a previous highly efficacious, easy to use and affordable anti-malarial agent was withdrawn from malaria endemic regions due to high levels of resistance. This review collated evidence from published-reviewed articles to establish prevalence of Pfcrt 76T and Pfmdr-1 86Y alleles in malaria affected countries following official discontinuation of chloroquine use.MethodsA review protocol was developed, registered in PROSPERO (#CRD42018083957) and published in a peer-reviewed journal. Article search was done in PubMed, Scopus, Lilacs/Vhl and Embase databases by two experienced librarians (AK, RS) for the period 1990-to-Febuary 2018. Mesh terms and Boolean operators (AND, OR) were used. Data extraction form was designed in Excel spread sheet 2007. Data extraction was done by three reviewers (NL, BB and MO), discrepancies were resolved by discussion. Random effects analysis was done in Open Meta Analyst software. Heterogeneity was established using I2-statistic.ResultsA total of 4721 citations were retrieved from article search (Pubmed = 361, Lilac/vhl = 28, Science Direct = 944, Scopus = 3388). Additional targeted search resulted in three (03) eligible articles. After removal of duplicates (n = 523) and screening, 38 articles were included in the final review. Average genotyping success rate was 63.6% (18,343/28,820) for Pfcrt K76T and 93.5% (16,232/17,365) for Pfmdr-1 86Y mutations. Prevalence of Pfcrt 76T was as follows; East Africa 48.9% (2528/5242), Southern Africa 18.6% (373/2163), West Africa 58.3% (3321/6608), Asia 80.2% (1951/2436). Prevalence of Pfmdr-1 86Y was; East Africa 32.4% (1447/5722), Southern Africa 36.1% (544/1640), West Africa 52.2% (1986/4200), Asia 46.4% (1276/2217). Over half, 52.6% (20/38) of included studies reported continued unofficial chloroquine use following policy change. Studies done in Madagascar and Kenya reported re-emergence of chloroquine sensitive parasites (IC50 < 30.9 nM). The average time (years) since discontinuation of chloroquine use to data collection was 8.7 ± 7.4. There was high heterogeneity (I2 > 95%).ConclusionThe prevalence of chloroquine resistance alleles among Plasmodium falciparum parasites have steadily declined since discontinuation of chloroquine use. However, Pfcrt K76T and Pfmdr-1 N86Y mutations still persist at moderate frequencies in most malaria affected countries.

Evaluation of Plasmodium vivax malaria recurrence in Brazil

BackgroundControl of vivax malaria in endemic areas requires management of recurrence. The Brazilian National Malaria Surveillance System (SIVEP-Malária) records every case of malaria in Brazil, but is not designed to differentiate between primary and recurrent infections. The aim of this study was to explore whether the information provided by SIVEP-Malária could be used to identify Plasmodium vivax recurrences, its risk factors and evaluate the effectiveness of short course primaquine (7–9 days: total dose 3–4.2 mg/kg) in preventing relapses.MethodsIn this observational retrospective cohort study, data matching of SIVEP-Malária records was undertaken using bloom filters to identify potential recurrences defined as microscopically-confirmed P. vivax episodes from the same individual occurring within a year. Generalized Estimation Equation (GEE) models were used to determine predictors of recurrence. Extended Cox-based conditional Prentice–Williams–Peterson models (PWP) models were used to evaluate time to recurrence.ResultsBetween June 1, 2014 and May 31, 2015, 26,295 episodes fulfilled the criteria of potential recurrence among 154,970 reported malaria episodes. Age ≤ 3 years, being male, literate, not-indigenous and having domestic working activities were identified as risk factors for recurrence. There was no difference in time to recurrence or recurrence frequency between patients treated with 14-day or 7–9 day primaquine regimens (HR = 1.02, 0.96–1.09) and RR = 0.97 (0.90–1.04), respectively. The use of chloroquine alone was associated with a 1.43 (1.29–1.58, p < 0.0001) increased risk of P. vivax recurrence compared to patients who used chloroquine combined with short-course primaquine, the Brazilian standard of care. This was RR = 2.06 (1.48–2.86, p < 0.0001), RR = 1.90 (1.60–2.25, p = 0.0001) and RR = 1.14 (1.00–1.29, p = 0.05) for recurrences occurring between 3–28, 29–60 and > 60 days, respectively. PWP models showed that the time to recurrence was longer in recipients of both primaquine and artemisinin-based combination therapy (ACT) compared to patients treated with chloroquine alone or with concomitant primaquine, HR = 2.2 (1.62–2.99, p < 0.0001), HR = 1.27 (0.97–1.66, p = 0.08), respectively.ConclusionShort course primaquine was as effective as 14-day regimens and associated with a halving of the risk and delay in time to recurrence of P. vivax infections in comparison to chloroquine alone. The study demonstrates the feasibility of using record linkage on routine surveillance data to identify potential P. vivax recurrences, associated risk factors and impact of treatment.