Tropical Parasitology最新文献

Blood parasitic diseases remain a significant public health challenge in India, with malaria, lymphatic filariasis (LF), and visceral leishmaniasis (kala-azar) accounting for the highest disease burden among parasitic infections. India contributes a major share of the global burden, particularly for LF and kala-azar, and remains one of the few countries endemic for all three major blood parasites. These diseases remain endemic in several regions, particularly among marginalized and tribal populations. The complex epidemiology is compounded by asymptomatic carriers, atypical clinical manifestations, and coinfections, often leading to delayed diagnosis and incomplete treatment coverage. In addition, geographic inaccessibility, socio-economic deprivation, poor health-seeking behavior, and limited infrastructure further hinder elimination efforts. However, recent advances in molecular diagnostic methods and treatment strategies have opened a new window for precise detection and surveillance. This review provides a comprehensive overview of the current epidemiology, emerging challenges, and recent scientific and technological advances in the control and elimination of blood parasitic diseases in India. It emphasizes the critical need for a multisectoral, evidence-based approach, combining innovative tools, community engagement, and health system strengthening to achieve long-term, sustainable elimination.

Patients having human immunodeficiency virus infection or acquired immunodeficiency syndrome (HIV/AIDS) are prone to suffer from diarrhea due to parasitic infestations which are more common in developing countries. Cryptosporidium, Cystoisospora, and Microsporidia species are among the important diarrhea causing protozoan parasites responsible for significant morbidity and mortality in HIV-infected patients. Although HIV-2 infection is uncommon in India, it is reported infrequently from the various regions of India. Although infections due to these protozoan parasites are common in HIV/AIDS patients, mixed infection is rarely reported. Here, we report the case of concurrent Cryptosporidium and Cystoisospora infection with probable HIV-1 and HIV-2 co-infection.

Background: Acanthamoeba keratitis (AK) is a diagnostic challenge. Establishing a microbiological diagnosis using culture, polymerase chain reaction (PCR), and ascertaining genotype is the current global norm. Although ocular trauma and extended contact lens (CL) wearing are classical risk factors, evidence is accumulating that AK can result even in their absence. Aims & objectives: The study aimed to identify the risk factors, genotypes, and clinical outcomes associated with AK at our institution.

Materials and methods: In a prospective analysis, corneal scrapings, CL, and lens solution specimens processed in the department of parasitology between January 2019 and December 2021 were subjected to microscopy, axenic culture on nonnutrient agar, and 18SrRNA PCR. The amplified products were subjected to gene sequencing, and a phylogenetic tree was constructed using available sequences in the database.

Results: Ten cases of AK were identified by culture and PCR during the study period. Sequence analysis and phylogenetic tree revealed that nine were genotype T4 and one was T5. The mean age of the patients was 29.5 years (range: 16-39 years), and male: female was 9:1. History of CL wearing was present only in four patients and extended wear in only one. Another patient had a history of ocular trauma, while five others had no risk factor. All were treated with polymyxin, polyhexamethylene biguanide, and voriconazole, and two underwent therapeutic keratoplasty.

Conclusion: A high index of suspicion should be kept in patients even without classical AK risk factors. Microbiological diagnosis along with genotyping would add to the increasing database of global AK cases.

Background/objectives: Outside of Africa, India is the main contributor to malaria-related morbidity and mortality in Southeast Asia. This retrospective study included 6 years of malaria data (2018-2023) from three districts in Maharashtra: Gadchiroli, Gondia, and Nagpur. The study examines the patterns of malaria, the distribution of Plasmodium species, and the effects of malaria control efforts under the National Vector Borne Disease Control Programme (NVBDCP).

Materials and methods: Six years of data on all malaria indicators collected under NVBDCP were taken from the respective districts. The sociocultural behavior of the population was analyzed by visiting the study area.

Results: Gadchiroli, primarily a hilly/tribal area, had the highest number of malaria cases, with the slide positivity rate (SPR) and annual parasite index reaching their peak in 2021. On the other hand, Gondia and Nagpur had consistently low levels of malaria transmission, with minimal fluctuations in key epidemiological indicators. The analysis demonstrates the significant differences in malaria transmission across various landscapes, with the highest SPR observed in tribal and hilly areas, followed by rural areas, and the lowest in urban regions. Plasmodium falciparum was the dominant species in Gadchiroli and Gondia, while Plasmodium vivax was more prevalent in urban areas of Nagpur.

Conclusion: The study emphasizes the need for targeted interventions in high-risk areas, especially in tribal regions, where sociocultural factors and ecological conditions contribute to sustained transmission. The findings highlight the importance of ongoing surveillance, culturally sensitive education, and advanced diagnostic tools to eliminate malaria in India by 2030.

A 15-year-old female child who was diagnosed as HIV seropositive 5 months back presented to the Dermatology OPD with the presence of multiple intensely itchy oval to round papulo- nodular lesions of variable size scattered over her limbs, face, and trunk for last 3 months. The patient gave the history that the lesions first appeared over her limbs and then, gradually spread to her whole body without affecting mucous membranes and new lesions kept on appearing, whereas older lesions gradually increased in size over a period of last 3 months. A slit skin biopsy was done of the nodules and the Giemsa-stained impression smear revealed the following findings given in the picture and the patient was started on appropriate treatment.

Crab louse primarily infests the pubic hair causing phthiriasis pubis. Occasionally, it can also infest the eyelids mimicking blepharitis. We report a case of 51-year-old male with lice and nits on the lid margin.

The helminthic parasites have largely been looked upon as chronic infections in developing countries causing morbidity. The helminthic parasites, unlike other microbial pathogens, are unique in the way they interact with the host's immune system. Their size, complexity, and movement within the host trigger the host's immune response toward a relative state of hyporesponsiveness, favoring cohabitation. This immunomodulation has been a topic of much debate in the last decade. This review explicitly explains how helminthic parasites are capable of modulating the host's immune system and how this immunomodulation is brought about at different stages of immune activation. The proven and postulated mechanisms of altered antigen presentation and activation of both arms of the immune system, cell-mediated and humoral, are presented. The review further summarizes what effect this immunomodulation has on bystander immune responses and how the presence of helminthic parasites can contribute to alleviating immune-dysregulation conditions in the host. An updated account of the current usage of "worm therapy" in different autoimmune diseases, allergic conditions, and even cancer therapy is presented.