Background The absence of specific antivirals to treat COVID-19 leads to the repositioning of candidates’ drugs. Nitazoxanide (NTZ) has a broad antiviral effect. Methods This was a randomized, double-blind pilot clinical trial comparing NTZ 600 mg BID versus Placebo for seven days among 50 individuals (25 each arm) with SARS-COV-2 RT-PCR+ (PCR) that were hospitalized with mild respiratory insufficiency from May 20 th , 2020, to September 21 st , 2020 (ClinicalTrials.gov NCT04348409). Clinical and virologic endpoints and inflammatory biomarkers were evaluated. A five-point scale for disease severity (SSD) was used. Findings Two patients died in the NTZ arm compared to 6 in the placebo arm ( p = 0.564). NTZ was superior to placebo when considering SSD ( p < 0001), the mean time for hospital discharge (6.6 vs. 14 days, p = 0.021), and negative PCR at day 21 ( p = 0.035), whereas the placebo group presented more adverse events ( p = 0.04). Among adverse events likely related to the study drug, 14 were detected in the NTZ group and 22 in placebo ( p = 0.24). Among the 30 adverse events unlikely related, 21 occurred in the placebo group ( p = 0.04). A decrease from baseline was higher in the NTZ group for d -Dimer ( p = 0.001), US-RCP ( p < 0.002), TNF ( p < 0.038), IL-6 ( p < 0.001), IL-8 ( p = 0.014), HLA DR. on CD4 + T lymphocytes ( p < 0.05), CD38 in CD4 + and CD8 + T (both p < 0.05), and CD38 and HLA-DR. on CD4+ ( p < 0.01) Interpretation Compared to placebo in clinical and virologic outcomes and improvement of inflammatory outcomes, the superiority of NTZ warrants further investigation of this drug for moderate COVID-19 in larger clinical trials. A higher incidence of adverse events in the placebo arm might be attributed to COVID-19 related symptoms.

The data support the value of standard fecal examinations in human immunodeficiency virus-infected patients, even in the absence of diarrhea, since these examinations easily can be performed, with low costs, and frequently disclose treatable conditions.

Although giardiasis has been a threat to mankind for thousands of years, this protozoan infection was, until recently, relatively neglected. Giardia duodenalis is recognised as a major cause of parasite-induced diarrhoea in humans and animals, and is currently an important public health problem, placing a heavy burden on both diagnostic and treatment services at health care institutions, mostly in developing countries, but also in highly developed countries. Steady progress in recent years, using a combination of molecular, immunological, and clinical approaches, has substantially increased our understanding of Giardia and important aspects of the clinical manifestations that it causes. The purpose of this review is to provide an overview of the extent of Giardia infection, the implications of water and food in Giardia transmission, new aspects regarding clinical diagnosis and environmental detection, treatment, and some approaches towards prevention and control. A number of future research priorities are also presented.

Amongst the causes of diarrhea in developing countries, those of a parasitic origin are prominent in patients with AIDS.Opportunistic infections caused by intestinal parasites also vary according to the geographical area and the endemic levels in each location.The progressive decline of immunological and mucous defense mechanisms predisposes patients to early, intermediary and late gastrointestinal manifestations of HIV infection. 6 At later stages of the disease, the alterations in non-specific defense mechanisms in the production of Ig A and the reduction in local immune cell response also progress, thus increasing the susceptibility to a number of intestinal opportunistic pathogens, among which Cryptosporidium parvum, Isospora belli and Microsporidia species are the most prominent. 7After the emergence of AIDS, these parasites, until then known solely in veterinary medicine, were no longer considered as commensal organisms and are nowadays recognized as opportunistic pathogens common to these patients. Infections by these agents constitute a major secondary aggravating factor of the disease, often responsible for worsening the general health conditions, due to manifestations of diarrhea which are difficult to control, sometimes resulting in the death of the patient. CRYPTOSPORIDIASISCryptosporidiasis, a disease caused by an intracellular protozoan named Cryptosporidium sp, was described for the first time in 1907 by Tyzzer. This parasite was considered a commensal up to 1975, when it was identified as the cause of diarrhea in animals. 8 The first manifestation of cryptosporidiasis was reported by Nine et al. in 1976, and the disease became a major concern when the notification of the first 21 patients was given, 14 of whom died of chronic diarrhea caused by Cryptosporidium sp infection. 9 It is worth noting that outbreaks of epidemic linked to contaminated water are of extreme importance for the dissemination of this parasite such as the 1993 Milwaukee (USA) cryptosporidiasis outbreak, in which 403,000 human cases were reported, thereby becoming a relevant public health concern.10-12 After this outbreak, it was recommended that immunocompromised patients should be extremely careful with water, foodstuffs and contact with animals.Cryptosporidiasis is distributed over all continents. In Haiti and the African continent the prevalence is 50%, 13 while in the USA it ranges from 3 to 4%.14 In Brazil, due to the continental size of the country, the rates of incidence vary with the location. In the city of São Paulo, for instance, reports have referred to levels around 12.1 to 24.44%. [15][16][17] However, the latest epidemiological report on Brazil, dated February 1998, shows a cryptosporidiasis rate of only 3.5%. 18Cryptosporidiasis in AIDS patients usually causes chronic, bulky and intermittent diarrhea, with liquid non-bloody stools, accompanied by pain and abdominal colic, and a noticeable loss of weight can be observed. 8Asymptomatic cases are rarely described, occurring mostly in developing countries with pati...