Introduction and objective: According to the World Health Organization (WHO) more than 95% of all parasitic infections reported globally result from poverty, poor personal hygiene practices, open defecation practices, consumption of contaminated drinking water, and improper handling of food....

Madagascar is one of the poorest countries in the world. The country’s extreme weather conditions, poor sanitation, and weak economy facilitate the spread of parasitic diseases. Infections with intestinal parasites are particularly dangerous for children because they can cause malnutrition and anemia, which, in turn, have a negative effect on children’s cognitive functions and physical development. The aim of the present study was to analyze the prevalence of intestinal parasites and to assess hematological parameters in a group of children living in northern Madagascar. The screening was conducted in May 2024 in the Clinique Medicale Beyzym in Manerinerina, the Ambatoboeny district. It involved a sample of 208 children aged 0–17 years. Single stool samples were collected from all study participants. The samples were fixed in SAF fixative and then transported from Africa to Europe for further diagnostics at the Department of Epidemiology and Tropical Medicine, the Military Institute of Medicine–the National Research Institute in Poland. First, the samples were analyzed by light microscopy methods using three different diagnostic techniques (direct smear, decantation with distilled water, and the Fülleborn method). Next, they were tested by molecular biology methods (real-time PCR). Blood samples for the assessment of hematological parameters were collected at the healthcare center in Madagascar. The prevalence of intestinal parasites in the study sample was 61.5%. Helminths were found in 15.2% of the investigated children, and Giardia intestinalis (20.5%) was found to be the most prevalent parasite in the study population. Most infections were caused by potentially pathogenic stramenopila Blastocystis spp. (32.0%). Mean Hb, HCT, MCV, MCH, and MCHC levels in the study participants were below normal values. However, no correlation was found between the presence of a parasitic infection and low hematological parameters, which are a clinical sign of anemia. High rates of infections with intestinal parasites in children living in northern Madagascar support the necessity to introduce long-term preventive measures, which would limit the spread of parasitic diseases in the Malagasy population. Low hematological parameters in non-infected children may be indicative of persistent malnutrition or infection with other parasites, e.g., malaria or schistosomiasis.

Poor sanitation, improper food handling, limited access to safe drinking water sources, and limited access to healthcare services contribute to a high prevalence of infections caused by soil-transmitted helminths (STHs) among the BaAka Pygmies, an indigenous community living in Central Africa. The aim of this study was to determine the rates of STH infections in the BaAka people inhabiting the rain forests of the south-western parts of the Central African Republic (CAR) as well as to examine the validity of biannual deworming with a single dose of albendazole 400 mg in high-risk communities exposed to extreme environmental conditions. The study was conducted in August 2021 and involved a sample of 49 BaAka Pygmies inhabiting the rain forest of the Sangha-Mbaéré Prefecture, CAR. The study consisted of collecting single stool samples from each participant and examining the samples for intestinal parasites by light microscopy methods. The collected samples were fixed in SAF fixative and next transported from Africa to Europe, where they were analyzed by light microscopy using three different diagnostic methods (direct smear in Lugol’s solution, the Fülleborn’s flotation, the Kato–Katz thick smear) at the Department of Epidemiology and Tropical Medicine in Gdynia, Poland. Microscopic examination found that 61.2% of the study group were infected with at least one helminthic species. The parasitological screening found invasions with four different species of nematodes, of which hookworm invasions were the most prevalent. The study results demonstrated that although the WHO-recommended mass deworming, which is provided to the BaAka Pygmies in healthcare centers set up on the premises of catholic missions, can effectively reduce the number of infections with soil-transmitted helminths, the prevalence of STH infections remains high in the region. The study findings suggest that in order to contain the spread of STHs in the local community, it will be necessary to implement additional preventive measures, apart from only conducting mass deworming programs.

Schistosomiasis is a parasitic disease that is considered a major threat to public health in Madagascar. The condition is endemic in more than 90% of the country’s districts. It is estimated that as much as 52% of the country’s general population is infected with Schistosoma spp. trematodes. The aim of the present study was to assess the prevalence values of Schistosoma haematobium infections in a population of children living in northern Madagascar and to determine the impact of trematode infections on the hematological profiles of the children included in the study. This screening study was conducted in 2024, and it involved a group of 170 children aged 0–17 years. The participants were required to provide urine samples for microscopic and molecular examination. The urine samples were preserved on Whatman 903 protein sever cards using the dried urine spot (DUS) sampling technique and then were transported from Madagascar to a molecular laboratory in Poland, where the samples were tested for the presence of S. haematobium. The present study found that the incidence of S. haematobium infections in the study group consisting of 170 children was as high as 67.6%. The authors observed a reduction in mean hemoglobin (Hb) and mean corpuscular hemoglobin concentration (MCHC) values in the infected children. In spite of continuous efforts to prevent the transmission of schistosomiasis in endemic countries (WHO-recommended mass drug administration campaigns), the incidence of S. haematobium infections was found to be exceptionally high among the study participants. S. haematobium infections present with a characteristic hematological picture showing signs of increased immune response and anemia. The DUS technique has been successfully used for the molecular diagnosis of S. haematobium. This method opens up possibilities for more effective and less expensive sample collection.

Neglected tropical diseases (NTDs) are a group of illnesses which usually present with a chronic clinical picture. NTDs can lead to permanent disability and are often associated with social stigma. In many developing countries where NTDs are endemic, there are no diagnostic tools for the safe storage and transport of biological samples, and there are no specialist diagnostic centers where the samples could be processed. The transport of biological samples (blood, urine) collected in field conditions and brought to laboratories located in developed countries requires the maintenance of the cold chain during transportation. Ensuring temperature control during transport could be problematic or even impossible to achieve; it is also expensive. A helpful solution to this problem is to use the dried matrix spot (DMS) technique, which seems to be a reliable method for collecting biological samples to be used for screening purposes and conducting epidemiological surveillance of NTDs in developing countries. This article is an overview of how DMSs can be used in the diagnosis of most neglected tropical diseases.

Malaria remains a major public health threat in Sub-Saharan Africa. According to the World Health Organization (WHO) estimates, Plasmodium falciparum species account for nearly 100% of the malaria cases occurring on the African continent. According to the Centers for Disease Control and Prevention (CDC), falciparum malaria predominates, but non-falciparum species are also present in Africa. The aim of the study was to assess the occurrence of asymptomatic malaria cases, as well as to identify Plasmodium species at two different settings with the lowest index of infections in Tanzania (according to the Tanzanian Ministry of Health < 1%), i.e., on the mainland (Arusha Region) and on the Pemba Island (Zanzibar Archipelago). The study was conducted in June 2023 and involved 722 individuals, including 449 residents of mainland Tanzania and 273 residents of the Zanzibar Archipelago. The screening consisted of two phases. In the first one, which was carried out at two different settings, i.e., in the Karatu Lutheran Hospital (Arusha Region, mainland Tanzania) and the Amal Hospital (Pemba, Zanzibar Archipelago), mRDTs (malaria rapid diagnostic tests) were performed, haemoglobin concentrations were measured, and blood samples for further molecular tests were collected onto Whatman micro cards from each of the individuals involved. In the second phase (conducted in Poland, Europe), RT-PCR tests for malaria were performed. The screening found asymptomatic Plasmodium infections in 4.2% of the study subjects from mainland Tanzania and in 4.8% from the Archipelago. The research confirmed cases of P. falciparum malaria but also found single cases of mixed infections with P. falciparum + P. malariae or P. ovale. The results demonstrated that the occurrence of malaria in northern mainland and Zanzibar Archipelago is higher than the official MoH reports present. The study findings are consistent with the reports by CDC, which suggest that non-falciparum species are also present in Sub-Saharan Africa.