Beneficial and Harmful Effects of Monoclonal Antibodies for the Treatment and Prophylaxis of COVID-19: Systematic Review and Meta-Analysis

BACKGROUND

We systematically assessed beneficial and harmful effects of monoclonal antibodies for coronavirus disease 2019 (COVID-19) treatment, and prophylaxis in individuals exposed to severe acute respiratory syndrome coronavirus 2.

METHODS

We searched 5 engines and 3 registries until November 3, 2021 for randomized controlled trials evaluating monoclonal antibodies vs control in hospitalized or non-hospitalized adults with COVID-19, or as prophylaxis. Primary outcomes were all-cause mortality, COVID-19-related death, and serious adverse events; hospitalization for non-hospitalized; and development of symptomatic COVID-19 for prophylaxis. Inverse variance random effects models were used for meta-analyses. Grading of Recommendations, Assessment, Development, and Evaluations methodology was used to assess certainty of evidence.

RESULTS

Twenty-seven randomized controlled trials were included: 20 in hospitalized patients (n = 8253), 5 in non-hospitalized patients (n = 2922), and 2 in prophylaxis (n = 2680). In hospitalized patients, monoclonal antibodies slightly reduced mechanical ventilation (relative risk [RR] 0.74; 95% confidence interval [CI], 0.60-0.9; I² = 20%, low certainty of evidence) and bacteremia (RR 0.77; 95% CI, 0.64-0.92; I² = 7%, low certainty of evidence); evidence was very uncertain about the effect on adverse events (RR 1.31; 95% CI, 1.02-1.67; I² = 77%, very low certainty of evidence). In non-hospitalized patients, monoclonal antibodies reduced hospitalizations (RR 0.30; 95% CI, 0.17-0.53; I² = 0%, high certainty of evidence) and may slightly reduce serious adverse events (RR 0.47; 95% CI, 0.22-1.01; I² = 33%, low certainty of evidence). In prophylaxis studies, monoclonal antibodies probably reduced viral load slightly (mean difference -0.8 log₁₀; 95% CI, -1.21 to -0.39, moderate certainty of evidence). There were no effects on other outcomes.

CONCLUSIONS

Monoclonal antibodies had limited effects on most of the outcomes in COVID-19 patients, and when used as prophylaxis. Additional data are needed to determine their efficacy and safety.

Efficacy and harms of tocilizumab for the treatment of COVID-19 patients: A systematic review and meta-analysis

INTRODUCTION

We systematically assessed benefits and harms of tocilizumab (TCZ), which is an antibody blocking IL-6 receptors, in hospitalized COVID-19 patients.

METHODS

Five electronic databases and two preprint webpages were searched until March 4, 2021. Randomized controlled trials (RCTs) and inverse probability treatment weighting (IPTW) cohorts assessing TCZ effects in hospitalized, COVID-19 adult patients were included. Primary outcomes were all-cause mortality, clinical worsening, clinical improvement, need for mechanical ventilation, and adverse events (AE). Inverse variance random-effects meta-analyses were performed with quality of evidence (QoE) evaluated using GRADE methodology.

RESULTS

Nine RCTs (n = 7,021) and nine IPTW cohorts (n = 7,796) were included. TCZ significantly reduced all-cause mortality in RCTs (RR 0.89, 95%CI 0.81-0.98, p = 0.03; moderate QoE) and non-significantly in cohorts (RR 0.67, 95%CI 0.44-1.02, p = 0.08; very low QoE) vs. control (standard of care [SOC] or placebo). TCZ significantly reduced the need for mechanical ventilation (RR 0.80, 95%CI 0.71-0.90, p = 0.001; moderate QoE) and length of stay (MD -1.92 days, 95%CI -3.46 to -0.38, p = 0.01; low QoE) vs. control in RCTs. There was no significant difference in clinical improvement or worsening between treatments. AEs, severe AEs, bleeding and thrombotic events were similar between arms in RCTs, but there was higher neutropenia risk with TCZ (very low QoE). Subgroup analyses by disease severity or risk of bias (RoB) were consistent with main analyses. Quality of evidence was moderate to very low in both RCTs and cohorts.

CONCLUSIONS

In comparison to SOC or placebo, TCZ reduced all-cause mortality in all studies and reduced mechanical ventilation and length of stay in RCTs in hospitalized COVID-19 patients. Other clinical outcomes were not significantly impacted. TCZ did not have effect on AEs, except a significant increased neutropenia risk in RCTs. TCZ has a potential role in the treatment of hospitalized COVID-19 patients.

Helicobacter pylori infection in children

Helicobacter pylori infection affects more than half of the world population and it occurs generally in childhood. It is associated with gastroduodenal ulcer, gastric atrophy, intestinal metaplasia, gastric adenocarcinoma and lymphoid tissue-associated lymphoma. It is difficult to eradicate this bacterium due to its high antimicrobial resistance. In children, the infection is asymptomatic in the majority of cases and complications are less common. Probable inverse relationships with allergic diseases and inflammatory bowel diseases are being studied. These reasons mean that the decision to diagnose and treat the infection in children is only considered in specific circumstances in which it provides true benefits. This review focuses on some current considerations regarding epidemiology, diagnosis and treatment of childhood infection, emphasising outcomes and treatment schemes in children.

Oesophageal eosinophilia and oesophageal diseases in children: are the limits clear?

Gastro-oesophageal reflux disease, eosinophilic oesophagitis and oesophageal motility disorders are among the most common diseases accompanying oesophageal eosinophilia. They have similarities and their limits are frequently not well defined. This article reviews the main characteristics relating to their similarities and differences, highlighting existing controversies among these diseases, in addition to current knowledge. In the case of a patient with symptoms of oesophageal dysfunction, it is suggested to carry out an integral analysis of the clinical features and diagnostic test results, including histology, while individualising each case before confirming a definitive diagnosis. Future investigation in paediatric patients is necessary to assess eosinophilic infiltration in the various layers of the oesophageal tissue, along with its clinical and pathophysiological implications.

Efficacy of 5-nitroimidazole compounds for giardiasis in Cuban children: systematic review and meta-analysis

Five-nitroimidazole (5-NI) compounds are among the most commonly used medications in the treatment of giardiasis. However, after more than five decades of their initial indication for such treatment, there are some concerns about the efficacy of 5-NIs in giardiasis. This study sought to compare the efficacy of any 5-NI with any other antigiardial drug for the treatment of Cuban children with giardiasis. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs). We searched CUMED, EBSCOhost and PubMed databases. Two reviewers independently assessed trial eligibility, trial quality and extracted appropriate data. The primary outcome was the parasitological cure. The effect estimate was the pooled relative risk (RR) with 95% confidence intervals (CI). We included seven RCTs in the systematic review, involving a total of 1046 children. When the effect of 5-NIs was compared with that of benzimidazole compounds, the pooled effect was significant and favored 5-NIs [the relative risk (RR) is 1.35, 95% CI =1.05 to 1.75], with high heterogeneity (4 studies, I2 =79%). Compared with chloroquine, the pooled effects of the 5-NIs were not significant [RR is 0.96, 95% CI=0.79 to 1.18, (2 studies, I2=68%)]. Our results support the use of 5-NIs (mainly tinidazole) as first-line therapy for Cuban pediatric patients infected with Giardia and may continue being used as reference drugs in future RCTs of giardiasis. These data could help inform policy decisions in Cuba. Caution is needed in extrapolating such data in other settings.

Treatment of refractory paediatric giardiasis using secnidazole plus albendazole: a case series

Giardia lamblia, the aetiological agent of human giardiasis, is a frequently identified protozoan infection of the upper small intestine. It mainly affects children and has a wide range of clinical manifestations, from asymptomatic carriage to acute or chronic diarrhoea with dehydration, abdominal pain, nausea, vomiting, excessive flatulence and weight loss. Standard treatment for giardiasis is commonly with 5-nitroimidazole (5-NI) compounds, or nitazoxanide; however, some individuals experience treatment failure. For such patients, a combination of two or more drugs may be a viable approach. We report our experience with 11 paediatric patients with drug-refractory giardiasis, for whom therapy with a combination of secnidazole (SNZ) (30 mg/kg/day, divided into 2 doses, for 3 days) and albendazole (ABZ) (400 mg daily for 5 days) resulted in cure for 9 of the 11 (82%) patients. This combination of drugs was well tolerated; only mild, transient, and self-limited side effects were reported and these did not require discontinuation of treatment. These results support the use of SNZ plus ABZ as an alternative treatment for paediatric patients with giardiasis who have failed conventional treatments. Further research is needed to establish the safety of this combination and how it compares to other combination strategies.

Efficacy of mebendazole in paediatric patients with giardiasis: A systematic review and meta-analysis

Mebendazole (MBZ), a benzimidazole compound, has received attention in treating patients with giardiasis because it has shown beneficial effects both in vitro and in vivo. The aim of this study was to assess with a systematic review and meta-analysis of randomized controlled trials (RCTs) the efficacy of MBZ compared to other antigiardial agents in children. We searched RCTs of MBZ for the treatment of Giardia infections published in PubMed and EBSCOhost. Application of inclusion and exclusion criteria, data extraction, and assessment of methodological quality were independently performed in duplicate. The primary outcome was the parasitological cure. We included 7 RCTs in the systematic review (639 patients). There was no clinical difference in the parasitological cure between MBZ and metronidazole (MTZ). The relative risk (RR) was 0.81 [95% Confidence Interval 0.61-1.09], with high heterogeneity (4 trials, I² = 81%). The prediction interval expected to cover the results of a new trial was wide enough (0.22-2.96) to support both a clinically relevant difference favouring either MBZ or MTZ. The decision to support any treatment should be based not only on efficacy but also safety and cost. Although our results suggest that MBZ may be an effective treatment option for children with Giardia infection, they should also be interpreted and translated into clinical practice with caution, as the evidence is based on a limited number of RCTs presenting high heterogeneity.

Potential sexual transmission of Giardia in an endemic region: a case series

We present four cases in which probable sexual transmission of Giardia lamblia was suspected. Diagnosing this mode of transmission in endemic areas is often difficult and should be considered only as possible, because exposure to poor sanitation and a potentially contaminated environment are always latent. However, as patients reported, there was no history of drinking tap water, exposure to recreational water, eating contaminated food, or other potential sources of infection but anilingus with an infected partner. We consider that in endemic countries, even when other more frequent modes of transmission could be playing the main role, the possibility of (re)infection due to sexual transmission should not be forgotten. Talking openly with patients, strengthening patient-specific preventive measures and counselling appear to be needed to reduce risks of Giardia infection transmission due to this often neglected route.

Combination therapy in the management of giardiasis: What laboratory and clinical studies tell us, so far

Treatment failures in patients suffering from giardiasis are not uncommon feature. The most frequent approach in these cases is to treat these patients with longer repeated courses and/or higher doses of the primary therapy, or using drugs from a different class to avoid potential cross-resistance. However, a higher rate of adverse events may limit this strategy. In this context, combination therapy (CT) is emerging as a valuable option against refractory giardiasis. In the attempt to evaluate the benefits of CT, a number of experimental studies, clinical series, and randomized clinical trials (RCTs), as well as several veterinary studies have been performed, with varying results. Here, we present a critical analysis of the available information regarding CT for the treatment of Giardia infection, as well as the authors' opinion with respect to its use. RCTs of combination therapy are limited and the optimal combinations and administration strategies need yet to be clarified. Analyses of the cost-effectiveness and RCTs of CTs for Giardia infection are required to assess the role of these drugs for the control of giardiasis, mainly in the case of treatment failures linked to suspected drug tolerance are the case.

A bibliometric study of international scientific productivity in giardiasis covering the period 1971–2010

Introduction: Despite years of relative neglect, interest in Giardia infection seems to be recently growing, perhaps in part due to its inclusion into the World Health Organization’s Neglected Diseases Initiative since 2004. The purpose of this study was to provide an overview of Giardia and giardiasis research over time, as represented by the quantity of published papers. Methodology: Data for this study were collected from the electronic PubMed/Medline database of National Library of Medicine's (NLM), due to it is easily accessibility and wide use. It was accessed online between April and December 2011. Data for the period 1971–2010 were obtained and information was downloaded using the EndNote program developed by Thomson Reuters. Results: During the study period, a total of 6,964 references (articles, reviews, editorials, letter to the editor, etc.) covering different aspects of Giardia and giardiasis were located in the PubMed database after applying the search strategy reported above. Most papers were original articles and published in English. Conclusions: In this first effort to explore the development and research productivity on giardiasis over time (no previously published bibliometric studies on giardiasis exist), two interesting characteristics of the Giardia and giardiasis literature were discovered: the concentration of papers over journals disseminating the research results, and that research in this field is growing and will likely continue to grow in the coming years.

Care-seeking behaviour and diagnostic processes for symptomatic giardiasis in children attending an academic paediatric hospital

Giardiasis is one of the commonest intestinal parasitic infections in Cuba. In order to determine care-seeking behaviour and diagnostic processes in paediatric in-patients with giardiasis, structured questionnaires were administered by interview mothers of children with giardiasis during January to December 2010. During the study period, 97 children were diagnosed with giardiasis, of whom 86 (88·6%) caregivers were interviewed. The median number of days from symptoms onset to the first presentation in a health unit was 2 days (range: 0-15 days). The pattern of care-seeking behaviour was variable; 41 (47·7%) of children initially visited the emergency unit in a paediatric hospital. Sixty-six children had, at least, one further contact for help before diagnosis of giardiasis was made (range: 1-5 contacts) and of the 128 contact visits, 94 (73·4%) were also targeted more to hospitals. There was a median time of 6 days between the first presentation to a health unit until diagnosis, which was mainly made by microscopic examination of duodenal aspiration. Among factors investigated in mothers, only knowing other person with giardiasis had significant association with their ability to suspect giardiasis [odds ratio (OR): 29·8, 95% confidence interval (CI): 3·71-239·4, P = 0·001]. Requesting a faecal specimen or ordering duodenal aspiration for microscopic examination during the first visit appeared associated with correct diagnosis (OR: 3·84, 95% CI: 1·57-9·40, P = 0·003). Efforts should be made to increase doctors' awareness of- and diagnostic skills for childhood giardiasis. At the same time, it is necessary to improve caregivers' awareness about giardiasis.

Management of chronic Giardia infection

Advances in our understanding of chronic giardiasis (CG) may improve our care of patients in this stage of the disease. This review proposes a new concept of CG and highlights the recent advances in our understanding and management of this condition. According to this review, management requires, initially, an accurate diagnosis, which may exclude several conditions that can mimic CG. Optimal treatment requires a tailored approach which includes the recognition of the known modifiable causes of this health condition, assessment of symptoms and potential complications, their treatment utilizing, if necessary, a multidisciplinary team, and an ongoing monitoring for the effect of therapy - weighing the efficacy of individual drugs - all of these together may lead to a successful treatment of CG.

Potential impact of macroclimatic variability on the epidemiology of giardiasis in three provinces of Cuba, 2010-2012

Climate change and variability are common phenomena affecting various infectious diseases. Many studies have been performed on vector-borne diseases; however, few studies have addressed such influences on intestinal parasitic diseases (e.g., giardiasis). In this study, using nonlinear Poisson regression models, we assessed the potential associations between macroclimatic variation and giardiasis cases in children and school workers from three provinces of Cuba in the context of large sampling and parasitological assessment. Between 2010 and 2012, 293,019 subjects were assessed, resulting in 6357 positive for Giardia (216.95 cases/10,000 pop.; 95%CI 211.7-222.2). The variation in time for those giardiasis rates ranged from 35.8 to 525.8 cases/10,000 pop. Nonlinear Poisson regression models between the ONI index and the giardiasis incidence indicated a significant association (p<0.01). With lower values of ONI, lower incidence of giardiasis was observed at Havana (pseudo r(2)=0.0576; p<0.001) and Guantánamo (pseudo r(2)=0.0376; p<0.001). Although these results are preliminary and the magnitude of association is not higher, the results were of statistical significance. This result indicates the need to assess in detail in further studies the impact of additional macroclimatic and microclimatic variables on the epidemiology of this still important intestinal parasitic disease, not only in Cuba but also in other countries of the Caribbean and Latin American region.

Sexual transmission of giardiasis: a neglected route of spread?

Sexually transmitted infections (STIs) are often discussed in the context of syphilis, gonorrhea, herpes, chlamydiasis and AIDS. However, since the past 30 years of the last century, epidemiology and natural history studies have led to improved understanding of giardiasis as a STI, as a result of oral-anal sexual contact. Studies suggest that Giardia is an increasingly recognized infection that may be underdiagnosed under the STI context. Health care providers should maintain a high index of suspicion for Giardia, obtain suitable diagnostic tests to identify and screen those at high risk for this infection, institute appropriate therapy, counsel patients regarding treatment compliance, follow-up, encourage partner notification and teach strategies for preventing the transmission of this disease, including the discussion of the risk of enteric infections after oral-anal sexual contact. We summarize some data concerning the research and clinical literature on Giardia infection as a STI and identify the specific recommendations for control of giardiasis as STI that available evidence indicates can reduce its transmission.

Abdominal pain and asthenia as common clinical features in hospitalized children for giardiasis

Giardiasis is a disease with worldwide distribution, although its prevalence differs from country to country. In order to investigate the clinical pattern of giardiasis in in-patient children, a case-control study was carried out. In-patient children who had Giardia lamblia infection were compared with non Giardia-infected children, focusing only on 4 clinical manifestations: diarrhoea, abdominal pain, asthenia and vomiting. In multivariable analysis, abdominal pain (odds ratio [OR] 4.71, 95% confidence intervals [CI] 2.66-8.32) and asthenia (OR 3.30, 95% CI 1.16-9.37) had positive and independent associations with Giardia infection. The present study supports the potential role of G. lamblia in abdominal pain in children who attend- and are admitted- to a hospital in Havana City, and highlights the importance to keep abdominal pain and asthenia in mind in hospital admitted children in the event of an association with an evocative epidemiological context.

Parental perceptions of giardiasis: a study in an outpatient paediatric hospital setting in havana, cuba

Background. Giardia lamblia is an important cause of diarrhoeal disease throughout the world. Giardiasis— a mild and self-limiting disease that this protozoan causes— is perceived as a harmful disease. Aim. To explore the general level of awareness about giardiasis, clinical features, mode of transmission, prevention, and consequences and describe the sources and channels of information caregivers would prefer using to be informed about this disease. Methods. A cross-sectional survey was conducted among caregivers attending to the outpatient paediatric hospital setting in Havana. Results. A total of 202 caregivers were interviewed. Nearly 73% considered giardiasis as a modern problem, and 39% considered that it could be a fatal disease. Although 76.7% were aware that small intestine is the organ affected, other localizations were cited. Abdominal pain and diarrhoea were recognized as the commonest symptoms. Around one-third could identify that giardiasis may spread through drinking unboiled water and unwashed vegetables other incorrect ways were mentioned; respondents with more than 12 years of formal education were more likely to have better knowledge. Discussion. Strategies to control giardiasis need to be through an integrated approach aiming at boosting caregivers' knowledge and encouraging healthcare workers to act as a readily available source for health information.

Risk factors for Giardia infection among hospitalized children in Cuba

The risk factors associated with Giardia infection, in children hospitalized in Havana, Cuba, were recently explored. Children aged ≥5 years were more likely to be positive for Giardia infection than the younger children, with an odds ratio (OR) of 3·41 [95% confidence interval (CI) = 1·36-9·69]. The risk factors found to be associated with Giardia infection in univariate analyses were rural residence (OR = 3·01; CI = 1·23-7·35), belonging to a household that did not receive water from an aqueduct (OR = 3·27; CI = 1·21-8·91), drinking unboiled water (OR = 3·64; CI = 2·14-6·26), nail biting (OR = 3·47; CI = 1·97-6·08), eating unwashed vegetables raw (OR = 4·84; CI = 2·33-10·14), and a personal (OR = 3·23; CI = 1·58-6·59) or family history (OR = 3·96; CI = 1·53-10·47) of previous parasitic infection. In multivariate analyses, however, only two (modifiable) risk factors were found to be independently and significantly associated with Giardia infection: nail biting and eating unwashed vegetables raw. It therefore seems that, at least at the individual level, giardiasis-prevention activities in Havana should be focussed on health education to improve personal hygiene and food-related practices. If appropriately managed, the surveillance of drinking water and foodstuffs, for Giardia and other parasites, might also help to reduce the hospitalization of Cuban children.

Giardiasis: the ever-present threat of a neglected disease

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.

Hospitalization of Cuban children for giardiasis: a retrospective study in a paediatric hospital in Havana

The medical records of the 185 children who, in 2007, were admitted to the Academic Paediatric Hospital 'Centro Habana', in the Cuban capital of Havana, because of giardiasis were analysed retrospectively. A standardized form was used to collect data on the socio-demographic characteristics, clinical features, laboratory diagnosis, treatment and length of stay of each child. Information on the 15 children who had incomplete medical records was excluded from the data analysis. Of the remaining 170 children, 85 (50·0%) were aged 1-4 years, 97 (57·1%) were male, and 106 (62·4%), 92 (54·1%) and 69 (40·6%) had presented with diarrhoea, vomiting, and/or abdominal pain, respectively. Most (91·2%) of the cases had been diagnosed by the microscopical examination of a duodenal aspirate, and the drugs that had been most used frequently were quinacrine and tinidazole, which had been given to 72 (42·4%) and 62 (36·5%) of the cases, respectively. The mean length of hospital stay was 4·9 days. Such information on the clinical characteristics of giardiasis among children living in an endemic area may be valuable to paediatricians and public-health officials who wish to screen for the disease.

A randomized, controlled, open-label trial evaluating the efficacy and safety of chloroquine in the treatment of giardiasis in children

BACKGROUND

Giardia duodenalis is among the commonest protozoan parasites in the intestinal tract of humans and may cause significant morbidity worldwide. Although there are several antigiardial agents, treatment failures have been commonly reported.

OBJECTIVE

To compare the efficacy and safety of chloroquine (CQ) versus metronidazole (MTZ) in the treatment of children with confirmed G duodenalis mono-infection.

METHODS

A randomized, controlled, open-label trial was carried out at the Cuban Institute of Gastroenterology. One hundred and twenty-two children were randomly assigned to receive either CQ (10 mg/Kg bodyweight twice a day for five days) or MTZ [15 mg/Kg bodyweight divided in three daily does for five days]. All children were asked to provide three faecal samples on days 3, 5 and 7 after treatment completion. Children were considered to be cured, if no Giardia trophozoites or cysts were found in any of the three post-treatment faecal specimens evaluated by direct wet mounts and/or after Ritchie concentration techniques.

RESULTS

The frequency of cure was a little higher for CQ than for MTZ but the difference was not statistically significant. Headache was more common in patients treated with CQ as was bitter taste. Yellowish colouration of the urine was more frequent in the MTZ treated group.

CONCLUSION

Chloroquine, for five days, is as efficacious as the recommended treatment with MTZ in children infected with G duodenalis.

Giardiasis--why do the symptoms sometimes never stop?

Although giardiasis is considered by most medical practitioners to be an easily treated infection, prolonged symptoms due to, or following, Giardia duodenalis infection can have a significant impact on quality of life. Symptom recurrence, including abdominal symptoms and fatigue, can result from re-infection, treatment failure, disturbances in the gut mucosa or post-infection syndromes. In developed countries, these sequelae can have an enormous impact on quality of life; in developing countries, particularly in children, they add yet another burden to populations that are already disadvantaged. Here, we outline current knowledge, based on individual case sequelae from sporadic infections, observations of population effects following outbreaks and studies of phenotypic and genotypic diversity between morphologically identical isolates of parasites. We also raise further questions, looking for clues as to why giardiasis sometimes becomes an intrusive, long-term problem.

Treatment of intestinal protozoan infections in children

Intestinal protozoan infections are a worldwide problem in both industrialised and unindustrialised countries; in the latter they may be the cause of significant morbidity and mortality. Children, in particular, are more likely to experience considerable morbidity. Most intestinal protozoan infections can cause acute or chronic diarrhoea in healthy individuals and may result in intractable, life-threatening illness in patients with immunosuppressive diseases such as AIDS. Adequate identification and treatment of these infections may provide significant benefit for individual patients and public health. This article presents an update on the pharmacotherapy currently available for amoebiasis, giardiasis and other intestinal protozoan infections.

Mebendazole in parasitic infections other than those caused by soil-transmitted helminths

Mebendazole, a benzimidazole carbamate compound, is currently in use for human medical practice against soil-transmitted helminthiasis (STH) and enterobiasis. However, it has been demonstrated that its spectrum of activity is broad and goes beyond those infections. Several studies provide evidence that this drug, taken at higher doses than used for STH and enterobiasis, could be sufficiently effective on some protozoa, nematodes and cestodes.

Prevalence, risk factors and clinical features associated with intestinal parasitic infections in children from San Juan y Martínez, Pinar del Río, Cuba

A cross-sectional study was carried out in 200 children aged 5-15 years, to examine the presence of intestinal parasitic infections (IPIs) and to assess the risk factors and clinical features associated with them in children in San Juan y Martinez (SIM), Cuba. Three fresh faecal samples were collected from each child and were examined by direct wet mount, brine flotation, formalin-ether and Kato-Katz techniques. Data relating to demography, source of drinking water, personal hygiene habits and clinical features were also collected Living in the rural area was significantly associated with the highest infection rates (p < 0.01). According to clinical features and laboratory examinations, children with abdominal pain were about four times more likely to have IPIs (OR 4.05, CI, 1.11, 13.18) especially soil-transmitted helminths (STH). We suggest that IPIs, especially STH, in SJM should be strongly suspected in children with abdominal pain from rural areas. Targeted and frequent interventions to control these infections are needed in this municipality.

The treatment of giardiasis in children: single-dose tinidazole compared with 3 days of nitazoxanide

Giardia lamblia is among the commonest intestinal protozoa world-wide and may cause significant morbidity, especially in children. Although 5-nitroimidazole compounds have formed the mainstay of giardiasis treatment for several years, the increasing number of reports of refractory cases given these and other antigiardial agents has raised concern and led to a search for other compounds. The aim of the present study was to compare the efficacy and safety, in the treatment of children infected with G. lamblia, of nitazoxanide, given at a dose of 7.5 mg/kg twice a day for 3 days, with those of tinidazole, given as a single dose of 50 mg/kg. Overall, 166 children, each proven to be infected with G. lamblia by the microscopical examination of a faecal sample, were included in the open and randomized trial, each being allocated to receive nitazoxanide or tinidazole. The parents of each treated child were asked to collect two faecal samples from the child between 5 and 10 days after the completion of treatment, for the parasitological follow-up. Only if no G. lamblia were found in both post-treatment samples from a child was that child considered cured. Among the 137 children who completed the study (74 given nitazoxanide and 63 given tinidazole), the frequency of parasitological cure following a single dose of tinidazole was significantly higher than that following six doses of nitazoxanide (90.5% v. 78.4%; P<0.05). Both treatment schedules were well accepted and well tolerated, with only mild, transient and self-limited side-effects reported. The commonest symptom on enrolment, diarrhoea, generally cleared 2-6 days after the initiation of treatment. Although apparently less efficacious than tinidazole, nitazoxanide remains a good candidate for the treatment of children with G. lamblia infection.

Intestinal protozoan and helminth infections in the Municipality San Juan y Martínez, Pinar del Río, Cuba

A cross-sectional study was carried out to determine the prevalence of intestinal parasitic infections and the intensity of soil-transmitted helminths (STHs) among children who attend the educational centres of San Juan y Martinez, Cuba. Ascaris lumbricoides, Blastocystis hominis and Giardia lamblia were the most common parasites found, with prevalence rates of 40.5%, 38.5% and 25%, respectively. In total, 91% of children harboured at least one type of intestinal parasite. The rates and intensity of intestinal parasitic infections found permit us to speculate that the conditions that predispose to acquire intestinal protozoan and STH infections persist in this municipality.

Giardiasis: a pharmacotherapy review

Giardia lamblia, the cause of human giardiasis, is among the most common intestinal protozoa worldwide. Human infection may range from asymptomatic shedding of giardial cysts to symptomatic giardiasis, being responsible for abdominal cramps, nausea, acute or chronic diarrhoea, with malabsorption and failure of children to thrive. At present, treatment options include the nitroimidazoles derivatives; especially metronidazole, which has been the mainstay of treatment for decades and is still widely used. The increasing number of reports of refractory cases with this group of drugs and other antigiardial agents, has raised concern and led to a search for other compounds, some of which have arisen due to the introduction of drugs initially addressed to other diseases. The present article examines some of the most important points of antigiardial pharmacotherapy available at present and the future prospects of development of new agents.

A randomized, controlled, open-label trial of a single day of mebendazole versus a single dose of tinidazole in the treatment of giardiasis in children

BACKGROUND

Giardia duodenalis is the most commonly detected parasite in the intestinal tract of humans and 5-nitroimidazole compounds, quinacrine and furazolidone have been used against giardiasis. However, cases refractory to treatment with these drugs are becoming more common worldwide.

OBJECTIVE

To compare the efficacy and safety of mebendazole versus tinidazole in the treatment of giardiasis.

RESEARCH DESIGN AND METHODS

122 children (aged 5 to 15 years) of both sexes with confirmed Giardia duodenalis cysts or trophozoites in their stool samples were randomly separated into two groups of 61 individuals. Each group received either mebendazole 200 mg three times for 1 day or tinidazole 50 mg/kg in a single dose. The evaluation of the efficacy was based on parasitological response. Parents or legal guardians of each child were asked to provide three fecal samples on days 3, 5, and 7 after treatment completion. A child was considered to be cured if no Giardia trophozoites or cysts were found in any of the three post-treatment fecal specimens evaluated by direct wet mounts and/or after Ritchie concentration techniques.

RESULTS

The frequency of cure was higher for tinidazole (81.97%) than for mebendazole (63.93%); the difference was statistically significant (p < 0.05). Transient abdominal pain was more common in children treated with mebendazole (p < 0.05), whereas loss of appetite, bitter taste, headache, vomiting, and nausea were more common in the tinidazole-treated group (p < 0.05).

CONCLUSIONS

Three doses of mebendazole, in a single day, are inferior to a single dose tinidazole in the treatment of giardiasis.

Randomized clinical study of five days apostrophe therapy with mebendazole compared to quinacrine in the treatment of symptomatic giardiasis in children

AIM: To compare the efficacy and safety of five days apostrophe therapy of mebendazole (MBZ) versus quinacrine (QC) on human giardiasis in children.

METHODS: A clinical trial was carried out in paediatric patients (aged 5-15 years) with confirmed symptomatic G. duodenalis mono-infection. Patients were randomly assigned to receive either MBZ [200 mg taken three times per day (TID) (n = 61)] or QC [2 mg/kg bodyweight tid (n = 61)], both for five days. Follow-up faecal samples were obtained at 3, 5 and 7 d after the end of the treatment.

RESULTS: Although the frequency of cure was higher for QC (83.6%) than for MBZ (78.7%), the difference was not statistically significant (P > 0.05). Adverse events were reported more in the QC group (P < 0.05), all of them transient and self-limiting.

CONCLUSION: Despite final cure rates ocurring lower than expected, the overall results of this study reconfirmed the efficacy of MBZ in giardiasis and also indicate that, although comparable to QC, at least in this setting the 5 d course of MBZ did not appear to improve the cure rates in this intestinal parasitic infection.

A randomized trial comparing mebendazole and secnidazole for the treatment of giardiasis

To compare the efficacy of the two drugs in the treatment of giardiasis, 146 children (aged 5-15 years) with confirmed Giardia lamblia infection were randomly allotted to treatment with mebendazole (200 mg three times daily for 3 days) or secnidazole (30 mg/kg, in a single dose). Parasitological response to treatment was evaluated in each child by the microscopical examination of faecal samples collected 3, 5 and 7 days after he or she had completed treatment. Although the frequency of cure was higher for secnidazole (79.4%) than for mebendazole (78.1%), the difference was not statistically significant (P > 0.05). Both treatment regimens were well tolerated, with only mild, transient and self-limiting side-effects reported. Mebendazole may be preferable to secnidazole in the treatment of giardiasis cases who have an history of intolerance to 5-nitromidazoles, and where infections with Giardia and soil-transmitted helminths frequently co-occur.

Intestinal coccidia in Cuban pediatric patients with diarrhea

From May to August 1999, we evaluated 401 patients from a pediatric hospital of Havana City. One group was composed of 113 patients with diarrhea admitted to the Gastroenterology ward and a second consisted of 288 patients without diarrhea, admitted for other reasons, and hospitalized within the same time period. Three stool samples were collected from each child and were examined using three parasitological techniques. When we compared the frequency of parasite species between both groups, we found Cryptosporidium spp. and Cyclospora cayetanensis, only in the group of children with diarrhea (P < 0.01). However, no significant differences were found in the occurrence of the other intestinal parasites (P > 0.05). In addition, in those children infected with Cryptosporidium, the diarrhea had a more prolonged duration (P < 0.01), while those infected with Cyclospora, the abdominal cramps or pain, and acute diarrhea were more frequently detected (P < 0.01). Our results showed that emerging intestinal coccidia are pathogens strongly associated in this group of children with diarrhea.

Comparison of chloroquine, albendazole and tinidazole in the treatment of children with giardiasis

In a comparative trial, 165 Cuban children with confirmed giardiasis were randomized to receive albendazole (400 mg/day for 5 days), chloroquine (10 mg/kg twice daily for 5 days) or tinidazole (50 mg/kg, as a single dose). Parasitological follow-up was based on faecal samples collected 7 and 10 days after the completion of treatment. The tinidazole and chloroquine appeared equally effective (P > 0.05), curing 91% and 86% of the children treated, respectively, and significantly better (P < 0.01) than the albendazole, which only cured 62% of the children given it. All three drugs were well accepted and tolerated, with only mild, transient and self-limiting side-effects reported. Chloroquine appears to be a good alternative to tinidazole for the treatment of paediatric patients with giardiasis.

[Intestinal parasitosis in children admitted to the Pediatric Teaching Hospital of Cerro, Havana City, Cuba]

A study on intestinal parasitism was conducted among 401 children admitted in the Pediatric Teaching Hospital of Cerro, from May to June, 1999. To this end, a representative, randomized and stratified sample by service was taken. 3 samples of feces per child were collected, preserved in formaldehyde, and processed by 3 parasitological methods. There was an intestinal parasitism prevalence of 15% at the hospital and there were no differences between the stratum of children admitted in Gastroenterology and the rest of the services as regards commensals and parasites in general (p > 0.05); however, commensals predominated in the second group (p < 0.01) The intestinal coccidia, Cryptosporidium parvum and Cyclospora cayetanensis prevailed in the Gastroenterology service over the rest of the services (p < 0.01). The age group over 4 (school children) was the most affected, both by protozoa and commensals (p < 0.01), excepting Cryptosporidium parvum that affected the infants more (p < 0.05). The analysis of some epidemiological antecedents showed that those children eating fruit without peeling and washing them, having vegetables withouth washing them first and walking barefooted were more prone to infection (RR > 1). A higher frequency of infection due to intestinal parasites was found among those living in rural areas, drinking well or river water, and defecating in latrines or in the open air (RR > 1). These results suggested that in spite of the existing knowledge of the epidemiological and risk factors, the intestinal parasites continue affecting the child population

Prevalence of intestinal parasites in Cuban acquired immunodeficiency syndrome (AIDS) patients

A coproparasitological study was carried out on 67 acquired immunodeficiency syndrome (AIDS) patients admitted at the Institute of Tropical Medicine 'Pedro Kouri'. The results were compared with 136 HIV-seronegative patients (control group) who were also hospitalised in the same period. In both groups monoparasitism was more prevalent than polyparasitism and intestinal protozoa were more prevalent than helminths. At least one intestinal parasite was found in 34 (51%) of the 67 AIDS patients and in 65 (48%) of the control group patients. Intestinal coccidia were only detected in AIDS patients; Cryptosporidium spp. was the most prevalent, with eight cases (11.9%), followed by Cyclospora cayetanensis with two cases (3.0%) and Isospora belli in one case (1.5%). The microsporidia Encephalitozoon (Septata) intestinalis and Enterocytozoon bieneusi were not detected. With regard to the prevalence of other pathogenic intestinal parasites in AIDS patients and the control group, no differences were found.