The clinical-epidemiological profile of malaria patients from Southern Venezuela, a critical hotspot in Latin America.

BACKGROUND: Venezuela accounted for 55% of the cases and 73% of the malaria deaths in the Americas in 2019. Bolivar state, in the southeast, contributes > 60% of the country's Plasmodium vivax and Plasmodium falciparum cases every year. This study describes the clinical-epidemiological characteristics of clinical malaria patients in this high-transmission area. METHODS: A prospective study was conducted on patients seeking medical attention in three medical centres in the state capital, Ciudad Bolivar, between June and October 2018. Malaria diagnosis was carried out using microscopy following national standards. Malaria-positive patients were examined for clinical symptoms, and haematological tests were performed at the time of diagnosis. Patients were followed up by telephone to evaluate malaria recurrences. RESULTS: Out of 287 patients, 200 (69.7%) were positive for P. vivax, 69 (24%) for P. falciparum, and 18 (6.3%) had mixed (P. vivax/P. falciparum) infections. Patients' median age was 33 years (IQR 20), 168 (69%) were men, and 40% practiced gold mining as the main occupation. Fever (96.5%), chills (91.3%), and headaches (90.6%) were the most frequent symptoms. At least one symptom associated with severe malaria was observed in 69 out of 161 patients with complete clinical evaluation (42.9%). Plasmodium vivax infections were found in 42 out of 69 (60.9%) severe cases; by contrast, P. falciparum and mixed malaria caused 34.8% (24/69) and 4.4% (3/69) of infections, respectively. Two patients died of cerebral malaria. Mean hemoglobin was lower in the patients infected with P. falciparum than those infected with P. vivax. Regardless of the parasite causing the infection, patients presented high levels of total bilirubin, aminotransferases (AST, ALT), and lactate dehydrogenase (LDH). Out of the 142 patients followed up by phone for three months (49.5% of the 287 patients), 35 (24.7%) reported recurrences. CONCLUSIONS: The high malaria prevalence among young male adults practicing gold mining suggests that this occupation is a significant risk factor. The unexpected high prevalence of P. vivax patients with at least one criteria of severe clinical disease is a matter of concern. Whether it is the result of a lack of timely diagnosis and effective treatment should be explored.

Defining malaria risks among forest workers in Aceh, Indonesia: a formative assessment.

BACKGROUND: Following a dramatic decline of malaria cases in Aceh province, geographically-based reactive case detection (RACD) was recently evaluated as a tool to improve surveillance with the goal of malaria elimination. While RACD detected few cases in households surrounding index cases, engaging in forest work was identified as a risk factor for malaria and infections from Plasmodium knowlesi-a non-human primate malaria parasite-were more common than expected. This qualitative formative assessment was conducted to improve understanding of malaria risk from forest work and identify strategies for targeted surveillance among forest workers, including adapting reactive case detection. METHODS: Between June and August, 2016, five focus groups and 18 in-depth interviews with forest workers and key informants were conducted in each of four subdistricts in Aceh Besar and Aceh Jaya districts. Themes included: types of forest activities, mobility of workers, interactions with non-human primates, malaria prevention and treatment-seeking behaviours, and willingness to participate in malaria surveys at forest work sites and using peer-referral. RESULTS: Reported forest activities included mining, logging, and agriculture in the deep forest and along the forest fringe. Forest workers, particularly miners and loggers, described often spending weeks to months at work sites in makeshift housing, rarely utilizing mosquito prevention and, upon fever, self-medicating and seeking care from traditional healers or pharmacies rather than health facilities. Non-human primates are frequently observed near work sites, and most forest work locations are within a day's journey of health clinics. Employers and workers expressed interest in undertaking malaria testing and in participating in survey recruitment by peer-referral and at work sites. CONCLUSIONS: Diverse groups of forest workers in Aceh are potentially exposed to malaria through forest work. Passive surveillance and household-based screening may under-estimate malaria burden due to extended stays in the forest and health-seeking behaviours. Adapting active surveillance to specifically target forest workers through work-site screening and/or peer-referral appears promising for addressing currently undetected infections.

Old friends and friendly fire: Pregnancy, hookworm infection, and anemia among tropical horticulturalists.

OBJECTIVES: Despite public health concerns about hookworm infection in pregnancy, little is known about immune profiles associated with hookworm (Necator americanus and Ancylostoma duodenale) infection during pregnancy. Fetal tolerance requirements may constrain maternal immune response to hookworm, thereby increasing susceptibility to new infections or increasing hemoglobin loss. To explore this possibility, we study systemic immune response and hemoglobin levels in a natural fertility population with endemic helminthic infection. METHODS: We used Bayesian multilevel models to analyze mixed longitudinal data on hemoglobin, hookworm infection, reproductive state, eosinophils, and erythrocyte sedimentation rate (ESR) to examine the effects of pregnancy and hookworm infection on nonspecific inflammation, cellular parasite response, and hemoglobin among 612 Tsimane women aged 15-45 (1016 observations). RESULTS: Pregnancy is associated with lower eosinophil counts and lower eosinophil response to hookworm, particularly during the second and third trimesters. Both hookworm and pregnancy are associated with higher ESR, with evidence for an interaction between the two causing further increases in the first trimester. Pregnancy is moderately associated with higher odds of hookworm infection (OR: 1.23, 95% CI: 0.83 to 1.83). Pregnancy and hookworm both decrease hemoglobin and may interact to accentuate this effect in the first-trimester of pregnancy (Interaction: ß: -0.30 g/dL; CI: -0.870 to 0.24). CONCLUSIONS: Our findings are consistent with a possible trade-off between hookworm immunity and successful pregnancy, and with the suggestion that hookworm and pregnancy may have synergistic effects, particularly in the first trimester.

Effect of malaria on productivity in a workplace: the case of a banana plantation in Zimbabwe.

BACKGROUND: Malaria is known to contribute to reduction in productivity through absenteeism as worker-hours are lost thus impacting company productivity and performance. This paper analysed the impact of malaria on productivity in a banana plantation through absenteeism. METHODS: This study was carried out at Matanuska farm in Burma Valley, Zimbabwe. Raw data on absenteeism was obtained in retrospect from the Farm Manager. Malaria infection was detected using malaria Rapid Diagnostic Test. Measures of absence from work place were determined and included; incidence of absence (number of absentees divided by the total workforce), absence frequency (number of malaria spells), frequency rate (number of spells divided by the number of absentees), estimated duration of spells (number of days lost due to malaria), severity rate (number of days lost divided by number of spells), incapacity rate (number of days lost divided by the number of absentees), number of absent days (number of spells times the severity rate), number of scheduled working days (actual working days in 5 months multiplied by total number of employees), absenteeism rate. RESULTS: A total of 143 employees were followed up over a 5-month period. Malaria positivity was 21%, 31.5%, 44.8%, 35.7% and 12.6% for January 2014 to May 2014, respectively. One spell of absence [194 (86.6%)] was common followed by 2 spells of absence [30 (13.4%)] for all employees. Duration of spells of absence due to malaria ranged from 1.5 to 4.1 working-days, with general workers being the most affected. Incidence of absence was 143/155 (93.3%), with total of spells of absence of over a 5-month period totalling 224. The frequency rate of absenteeism was 1.6 with severity rate of absence being 2.4. and incapacity rate was 3.7. CONCLUSION: Malaria contributes significantly to worker absenteeism. Employers, therefore, ought to put measures that protect workers from malaria infections. Protecting workers can be done through malaria educative campaigns, providing mosquito nets, providing insecticide-treated work suits, providing repellents and partnering with different ministries to ensure protection of workers from mosquito bites.

Rubber plantations and drug resistant malaria: a cross-sectional survey in Cambodia.

BACKGROUND: The ongoing spread of artemisinin resistant Plasmodium falciparum malaria is a major threat to global health. In response, countries in the Greater Mekong Sub-region, including Cambodia, have declared ambitious goals to eliminate malaria. Major challenges include the lack of information on the at-risk population-individuals who live or work in or near the forest where the malaria vectors are found, including plantation workers. This study aimed to address this knowledge gap through a cross-sectional survey conducted in rubber plantations in Cambodia in 2014. METHODS: The survey was conducted in two rounds in four provinces and included a malaria prevalence survey, analysis for the K13 genetic mutation, and a comprehensive behavioural questionnaire. Forty plantations were included in each round, and 4201 interviews were conducted. An additional 701 blood samples were collected from family members of plantation workers. RESULTS: Overall malaria prevalence was relatively low with adjusted PCR prevalence rate of 0.6% for P. falciparum and 0.3% for Plasmodium vivax, and was very heterogenous between plantations. There was little difference in risk between permanent residents and temporary workers, and between the two rounds. The main risk factors for P. falciparum infection were smaller plantations, age under 30 years, lack of self-reported use of a treated net and recent travel, especially to the Northeastern provinces. Proximity of plantations to the forest was also a risk factor for malaria in round one, while male gender was also a risk factor for malaria by either species. CONCLUSIONS: With Cambodia's P. falciparum elimination target on the horizon, identifying every single malaria case will become increasingly important. Plantations workers are relatively accessible compared to some other at-risk groups and will likely remain a high priority. Ongoing surveillance and adaptive strategies will be critical if malaria elimination is to be achieved in this setting.

LOW PREVALENCE OF INTESTINAL SCHISTOSOMIASIS AMONG FISHERFOLK LIVING ALONG THE RIVER NILE IN NORTH-WESTERN UGANDA: A BIOSOCIAL INVESTIGATION.

Mass drug administration has been less successful as a technique for controlling intestinal schistosomiasis (S. mansoni) than anticipated. In Uganda, the mass distribution of praziquantel has been provided to populations at risk of infection since the early 2000s, but prevalence mostly remains high. This is the case, for example, at locations in north-western and south-eastern Uganda. However, there is a remarkable exception. Among Madi fishing populations and their immediate neighbours, living close to the border with South Sudan, the rate of infection has dropped dramatically. A parasitological survey carried out at twelve fishing sites in 2013 identified only three cases of S. mansoni among 383 adults tested. This article asks: why is the prevalence of S. mansoni so low among fisherfolk in northern Uganda? Taking a biosocial approach, it suggests that the mass distribution of drugs, free of charge, has had an impact. However, the low prevalence of infection cannot be attributed to this alone. Other important factors may also have contributed to the decline in infection. These include changing fishing livelihoods, local attitudes to public health interventions, access to water and sanitation facilities, hygiene practices and the use of anti-malarial treatments. Above all, the article highlights the importance of investigating both social and biological dimensions of infection simultaneously, and of recognizing the local complexities of sustainably treating this debilitating parasitic disease.

Effectiveness of permethrin-treated clothing to prevent tick exposure in foresters in the central Appalachian region of the USA.

Outdoor workers are at risk from mosquito and tick bites and the extent to which exposures are linked to vector-borne disease is not understood. This pilot study characterizes for ester exposure to mosquitoes and ticks, and assesses effectiveness of permethrin-treated clothing for prevention of tick bites. Foresters (N = 34) from Kentucky, North Carolina, Ohio, Tennessee, Virginia, and West Virginia were placed into treatment (permethrin-treated clothing) or control (untreated clothing) groups. Foresters completed questionnaires about work-related tick/mosquito exposure and 454 ticks were collected/identified from May to June 2013. A time-weighted analysis based on information submitted by foresters about time working outdoors showed that control participants received a lower rate of tick exposure (0.15 tick bites/hour; 13 bites/person) compared to treatment participants (0.27 bites/hour; 21 bites/person). However, more control participants (85 %) received at least one tick bite compared to treatment participants (52 %). Outdoor workers should be aware of available protective measures, such as permethrin-treated clothing, that may mitigate occupational risks.

The global seroprevalence of Toxoplasma gondii infection in workers occupationally exposed to animals (1972-2023): a systematic review and meta-analysis.

Toxoplasma gondii, a ubiquitous zoonotic parasite infecting warm-blooded animals, poses a significant health threat to workers with occupational animal exposure (WOEA) due to their frequent contact with potential reservoirs. Existing data on T. gondii seroprevalence in the WOEA exhibits substantial global variation. This systematic review and meta-analysis, adhering to PRISMA guidelines, aimed to quantify the global seroprevalence of T. gondii infection among WOEA over the past five decades (1972-2023). We identified 66 eligible studies through a comprehensive search strategy encompassing English publications, with a total sample size of 15,279. A random-effects model with the Freeman-Tukey transformation in STATA v16.0 accounted for the high heterogeneity observed. We estimated the pooled global seroprevalence of T. gondii infection in WOEA at 41% (95% CI: 36-47%). Subgroup analyses revealed significant variations by gender: males (63%) vs. females (37%) (p < 0.05), occupation: non-livestock workers (54%), livestock workers (47%), slaughterhouse workers (44%), and veterinary personnel (27%) (p < 0.05). Geographic trends showed the highest prevalence in Africa (51%), followed by South America (49%), Europe (47%), Australia (43%), Asia (36%), and North America (23%; p < 0.05). Lower prevalence was observed in high-income (39%) and upper-middle-income (38%) countries compared to lower-middle-income (44%) and low-income (48%) countries (p < 0.05). This analysis underscores the high global seroprevalence of T. gondii in the WOEA, highlighting the need for targeted interventions in this high-risk population.

Strongyloidiasis in a nonagenarian who previously worked in conservancy services.

We report a case of strongyloidiasis in a patient born in Hong Kong and was possibly infected via her prior occupation in conservancy services. She presented with chronic diarrhoea, anorexia, and extensive scratch marks over the lower extremities. Further assessment yielded eosinophilia, intermittent dyspepsia, and an episode of unexplained Clostridium perfringens bacteraemia. She was treated with a course of albendazole. Subsequently, the eosinophilia and diarrhoea subsided.

[Buccal infection with Gongylonema pulchrum: an indigenous case in France]. / Infection buccale à Gongylonema pulchrum : un cas autochtone.

BACKGROUND: Although long known, infestations of the buccal mucosa by nematodes of the Gongylonema genus are rare, particularly in France. Herein we report a new case. PATIENTS AND METHODS: A 48-year old man consulted for itching in various parts of the buccal mucosa over the preceding weeks. The patient lived in a rural region in southern Alsace and had never visited Africa. His work comprised overseeing the unloading of flour at the port of Basel. The initial clinical examination was negative. However, the patient managed to photograph a filament previously present in his buccal mucosa, and to ultimately extract a worm. The latter was identified at the Strasbourg Institute of Parasitology by Pr Pesson as a nematode of the genus Gongylonema sp. pulchrum. No other treatment was considered necessary. DISCUSSION: It is important for dermatologists to be aware of this type of parasitosis. Its stereotyped clinical presentation allows ready diagnosis, but the possible absence of the parasite at the time of the visit may lead to a misdiagnosis of Ekbom syndrome (delusional parasitic infestation).

Investigation of Demodex Spp. prevalence among managers and workers of health hazard bearing and sanitary establishment.

BACKGROUND/PURPOSE: Two Demodex species are known to live on people. Demodex folliculorum lives in the openings of hair follicles alone or in groups. D brevis lives in the depths of the sebaceous glands alone. There are different related on the epidemiology of Demodex species have been published. METHOD: In this study, taking into account that the parasite is transmitted through close contact from person to person, we aimed to evaluate the relation between the presence of Demodex spp with gender and age among the Health hazard bearing and sanitary establishment operators and workers who came for porter examination. RESULTS: For this purpose, 862 male and 215 female patients with a total of 1077 volunteers from the face area of the standard superficial skin biopsy (SSSB) method and studied samples were taken. More than five mites in 1 cm(2) density was defined as positive. In investigated samples 37.3% Demodex spp. positivity was detected. Only two were found to be D brevis and the others were D folliculorum. The study revealed statistically significant relationships between the positivity of parasites with the occupational group, age and sex. CONCLUSION: Since the prevalence of Demodex among healthy individuals without any complaint was found to be 37%, we believe Demodex spp should be investigated in porter examinations of people who have dermatological complaints.

Participatory probabilistic assessment of the risk to human health associated with cryptosporidiosis from urban dairying in Dagoretti, Nairobi, Kenya.

We carried out a participatory risk assessment to estimate the risk (negative consequences and their likelihood) from zoonotic Cryptosporidium originating in dairy farms in urban Dagoretti, Nairobi to dairy farm households and their neighbours. We selected 20 households at high risk for Cryptosporidium from a larger sample of 300 dairy households in Dagoretti based on risk factors present. We then conducted a participatory mapping of the flow of the hazard from its origin (cattle) to human potential victims. This showed three main exposure pathways (food and water borne, occupational and recreational). This was used to develop a fault tree model which we parameterised using information from the study and literature. A stochastic simulation was used to estimate the probability of exposure to zoonotic cryptosporidiosis originating from urban dairying. Around 6 % of environmental samples were positive for Cryptosporidium. Probability of exposure to Cryptosporidium from dairy cattle ranged from 0.0055 for people with clinical acquired immunodeficiency syndrome in non-dairy households to 0.0102 for children under 5 years from dairy households. Most of the estimated health burden was born by children. Although dairy cattle are the source of Cryptosporidium, the model suggests consumption of vegetables is a greater source of risk than consumption of milk. In conclusion, by combining participatory methods with quantitative microbial risk assessment, we were able to rapidly, and with appropriate 'imprecision', investigate health risk to communities from Cryptosporidium and identify the most vulnerable groups and the most risky practices.

A case report on eosinophilic meningitis caused by Angiostrongylus cantonensis.

Angiostrongylus cantonensis is the most common cause of eosinophilic meningitis in humans. It is usually caused by ingestion of raw or inadequately cooked intermediate hosts or food contaminated with infective third-stage larvae. We describe a case of eosinophilic meningitis caused by A. cantonensis in a male Chinese patient. The patient had a history of eating raw fish and snail. We describe the clinical features of the patient, the diagnostic process and treatments. We also provide a brief update for physicians on the characteristics, diagnosis and treatment of eosinophilic meningitis caused by A. cantonensis, with particular emphasis on the update of prevalence and treatment of the disease in China.

Immunological correlates of cure in the first American cutaneous leishmaniasis patient treated by immunotherapy in Argentina. A case report.

A patient with localized cutaneous leishmaniasis due to Leishmania (Leishmania) amazonensis infection was treated with an antigen containing heat-killed L. (L.) amazonensis promastigotes plus BCG. Expression of T-cell differentiation, memory and senescence receptors markers were analyzed on T cell subpopulations, in order to establish the correlation between the percentages of expression of these receptors and his clinical status, at different stages of his follow up. The following case reports on the achievement of a successful clinical outcome with complete resolution after receiving immunotherapy. A thorough clinical and immunological follow up supporting the healing process of this patient's lesion is presented in detail.

[Malaria and life at sea: prophylactic regimens on merchant ships]. / Paludisme et vie embarquée: pour une chimioprophylaxie adaptée.

The purpose of this article is to describe requirements for protection/treatment of malaria on merchant ships. The first part of the article reviews recent data on the incidence of malaria in seagoing personnel. The second part provides advice on mosquito-bite prevention on merchant ships. The third part presents the most important information on prophylaxis for seafarers working in malarial risk areas. Several regimens are proposed. The last part of the article discusses curative treatment for malaria on merchant ships.

Examinations regarding the prevalence of intestinal parasitic diseases in Polish soldiers contingents assigned to missions abroad.

The aim of this paper is to present the program of diagnostic examinations regarding the detection and following treatment of intestinal parasitic diseases in the population of Polish soldiers serving in different climatic and sanitary conditions. Intestinal parasitoses remain one of the health problems of soldiers participating in contemporary military operations. This fact mainly results from unsatisfactory sanitary and hygienic standards in the regions where troops are deployed, contamination of water and soil, inappropriate processes of purifying drinking water, and the terrible condition of sewage systems, water purification plants, or sewage treatment facilities. The occurrence of such diseases is further facilitated by disregard of some basic principles of food and feeding hygiene. Mass examinations of Polish troops to find the prevalence of intestinal parasitoses will cause a decrease in the morbidity rate of parasitic diseases among Polish soldiers deployed in military operations. They can also lead to a decrease in expenditure on medical treatment of disease-related complications and on damages awarded to soldiers who have developed a serious disease while being engaged in a mission abroad.

Update: Malaria, U.S. Armed Forces, 2020.

Malaria infection remains an important health threat to U.S. service members who are located in endemic areas because of long-term duty assignments, participation in shorter-term contingency operations, or personal travel. In 2020, a total of 28 service members were diagnosed with or reported to have malaria. This was the lowest number of cases in any given year during the 10-year surveillance period and represents a 15.2% decrease from the 33 cases identified in 2019. The relatively low numbers of cases during 2012-2020 mainly reflect decreases in cases acquired in Afghanistan, a reduction largely due to the progressive withdrawal of U.S. forces from that country. The number of malaria cases caused by Plasmodium falciparum in 2020 (n=8) was the second lowest observed during the surveillance period. The percentage of 2020 cases of malaria caused by Plasmodium vivax (53.6%; n=15) was the highest during any given year of the surveillance period. The remaining 5 malaria cases were labeled as associated with other/unspecified types of malaria (17.9%). Malaria was diagnosed at or reported from 13 different medical facilities in the U.S., Germany, Africa, and Korea. Providers of medical care to military members should be knowledgeable of and vigilant for clinical manifestations of malaria outside of endemic areas.

Seroprevalence and risk factors of Toxoplasma gondii infection among veterinary personnel and abattoir workers in Central India.

Toxoplasmosis, caused by the protozoan parasite Toxoplasma gondii, is an important zoonotic infection. Veterinary personnel and abattoir workers are considered to be at a high risk of T. gondii infection owing to their occupational exposure. However, the association of T. gondii infection with occupational exposure to animals has not been determined in India. Hence, we analysed 139 and 126 blood samples of veterinary personnel and abattoir workers, respectively, for anti-T. gondii antibodies using enzyme-linked immunosorbent assay (ELISA), modified agglutination test (MAT) and indirect fluorescent antibody test (IFAT). The association of seroprevalence with sociodemographic profiles, work activities and dietary habits was determined in the study population. MAT, ELISA and IFAT results demonstrated nearly 46%, 48% and 47% seropositivity, respectively. MAT (kappa = 0.924) and IFAT (kappa = 0.962) results showed good agreement with ELISA results. Of the ELISA positive samples, 46% was copositive for IgG antibody, 1.5% for IgM antibody and 1.5% for both IgG and IgM antibodies. High IgG avidity was observed only in IgG+ IgM- and IgG+ IgM+ samples and not in IgM+ IgG- samples, indicating chronic T. gondii infection in most of the cases. Furthermore, multivariate analysis revealed that T. gondii seropositivity was associated with age > 30 years (odds ration [OR] = 1.992), cat at home (OR = 1.991), not wearing gloves (OR = 1.886), not wearing safety glasses (OR = 1.985) and contact with soil (OR = 1.695). These findings support the presence of a potentially significant association between T. gondii seropositivity and occupational exposure to animals.