Frequency and distribution of neglected tropical diseases in Mozambique: a systematic review

Is the incidence rate of colorectal cancer increasing in Mozambique?

Background

Colorectal cancer (CRC) is a significant global health concern, ranking as the third most common cancer and the second leading cause of cancer-related deaths. However, in Africa, CRC is the fifth most common invasive malignancy. Limited data hinder our understanding of the evolving burden of CRC in sub-Saharan Africa. This study explores CRC trends in Mozambique, utilising data from population-based oncological registries.

Methods

CRC data were gathered from Beira and Maputo population-based cancer registries, along with supplementary information from pathology-based and hospital-based registries. Comparative analyses were performed across different time periods, focusing on trends and epidemiological characteristics.

Results

Incidence rates of CRC in Maputo and Beira were relatively low historically. However, data from recent years showed an increase, especially in age groups above 50. Analyses from pathology-based and hospital-based registries affirmed the rising trend. The age-standardised incidence rate in Maputo (2015-2017) was 3.17 for males and 2.55 for females. Beira exhibited increasing rates between 2009 and 2020, particularly in individuals aged 50 and above.

Conclusion

The study reveals an emerging burden of CRC in Mozambique, challenging the perception of low incidence. The rising trend underscores the necessity for tailored interventions, emphasizing early diagnosis, preventive strategies, and investments in healthcare infrastructure to address the increasing CRC burden in the region.

Why Are We Still a Worm World in the 2020s? An Overview of Risk Factors and Endemicity for Soil-Transmitted Helminthiasis

PURPOSE

Soil-transmitted helminthiasis (STH) is one of the most common chronic infections in developing countries associated with poor socioeconomic and sanitary conditions. The main objective of this overview was to evaluate the influence of environmental factors, risk factors related to the host, and control strategies on the prevalence of STH in different regions of the world.

METHODS

LILACS, PubMed, Web of Knowledge, Embase, the Cochrane Library, and Clinical Trials (gray literature) databases were used to obtain the systematic reviews published until December 2020. The methodological quality of systematic reviews was assessed using the standard criteria recommended by AMSTAR.

RESULTS

The initial results of the bibliographic search identified 1448 articles, of which 66 studies were read in full and 16 met the inclusion criteria. All the reviews included in this overview associated variations in the global prevalence of STH with at least one of the factors related to the environment, host, and/or control strategies. Climate, temperature, soil moisture, precipitation, mass drug administration, lack of access to water, sanitation and hygiene (WASH), and non-use of footwear were considered the main factors associated with the prevalence of STH. Socioeconomic factors, low educational level, and wearing shoes were universal factors related to prevalence, regardless of the location studied.

CONCLUSION

The combination of environmental factors, with factors associated with hosts that predispose infection and reinfection of helminths, as well as the adoption of control strategies based on the treatment of target populations instead of the entire population, influenced the prevalence of STH in all the continents evaluated.

Single-Nucleotide Polymorphisms in the Beta-Tubulin Gene and Its Relationship with Treatment Response to Albendazole in Human Soil-Transmitted Helminths in Southern Mozambique

Soil-transmitted helminth (STH) cornerstone control strategy is mass drug administration (MDA) with benzimidazoles. However, MDA might contribute to selection pressure for anthelmintic resistance, as occurred in livestock. The aim of this study is to evaluate the treatment response to albendazole and the relationship with the presence of putative benzimidazole resistance single-nucleotide polymorphisms (SNPs) in the β-tubulin gene of STH in Southern Mozambique. After screening 819 participants, we conducted a cohort study with 184 participants infected with STH in Manhiça district, Southern Mozambique. A pretreatment and a posttreatment stool samples were collected and the STH infection was identified by duplicate Kato-Katz and quantitative polymerase chain reaction (qPCR). Cure rate and egg reduction rates were calculated. Putative benzimidazole resistance SNPs (F167Y, F200T, and E198A) in Trichuris trichiura and Necator americanus were assessed by pyrosequencing. Cure rates by duplicate Kato-Katz and by qPCR were 95.8% and 93.6% for Ascaris lumbricoides, 28% and 7.8% for T. trichiura, and 88.9% and 56.7% for N. americanus. Egg reduction rate by duplicate Kato-Katz was 85.4% for A. lumbricoides, 34.9% for T. trichiura, and 40.5% for N. americanus. Putative benzimidazole resistance SNPs in the β-tubulin gene were detected in T. trichiura (23%) and N. americanus (21%) infected participants at pretreatment. No statistical difference was observed between pretreatment and posttreatment frequencies for none of the SNPs. Although treatment response to albendazole was low, particularly in T. trichiura, the putative benzimidazole resistance SNPs were not higher after treatment in the population studied. New insights are needed for a better understanding and monitoring of human anthelmintic resistance.

Historical overview and geographical distribution of neglected tropical diseases amenable to preventive chemotherapy in the Republic of the Congo: A systematic review

Background

Neglected Tropical Diseases amenable to Preventive Chemotherapy (PC-NTDs) affect the poorest populations around the world, especially in Africa. Scientific information on the distribution and level of endemicity of these diseases in the Republic of the Congo (RoC) is scarce in the published literature. We sought to collect all available epidemiological data on PC-NTDs in the RoC to document the historical and current situation and identify challenges in reaching the elimination of NTDs.

Methods

We searched Medline and Horizon databases for studies published until to July 4^th, 2019, on onchocerciasis, lymphatic filariasis, soil-transmitted helminth infections, schistosomiasis, and trachoma in the RoC. Unpublished reports were also reviewed. We included all epidemiological studies containing community data and excluded case reports. Location, prevalence data, and dates of the studies were extracted.

Principal findings

We identified 933 records, of which 56 met the inclusion criteria. The articles published before 1960 mainly concerned onchocerciasis and schistosomiasis. Despite a low number over the studied period, since 2005 there has been a steady increase in the number of publications. Most of the studies were cross-sectional and conducted in the general population. Trachoma is endemic in the Sangha and Likouala departments (prevalence of trachomatous inflammation-follicular > 5% in some villages), and further mapping is essential to properly assess the burden of this disease in the country. While the prevalence of soil-transmitted helminths is still high (over 20%) in a large part of Congo, cases of lymphatic filariasis (based on Wuchereria bancrofti antigenaemia and/or microfilaraemia) and onchocerciasis are becoming rare and very focused. To achieve the elimination of PC-NTDs, further intervention is required.

Conclusions

Except for trachoma, whose epidemiological situation should be better evaluated, PC-NTDs are endemic in the RoC, and actions to control them have been taken by health authorities. To eliminate PC-NTDs, which are still present in some locations, new mapping surveys are needed, and increased investment in scientific research should be encouraged in the country.

For many years, the Republic of the Congo has implemented control programs to combat neglected tropical diseases that cause severe disabilities. By tracing the past and recent distribution of these diseases through the analysis of epidemiological studies, we show that most remaining NTDs are located in defined foci of infection, maintained depending on ecology and lifestyle habits. However, the small number of recent studies limits the production of new knowledge, which would be useful for a better understanding of epidemiological patterns and to accelerate NTD elimination.

The burden of T. solium cysticercosis and selected neuropsychiatric disorders in Mocuba district, Zambézia province, Mozambique

BACKGROUND

Taenia solium (neuro-)cysticercosis, a neglected tropical disease, can be associated with epileptic seizures and other neuropsychiatric (= neurological and psychiatric) disorders. This study aimed to evaluate the association of T. solium cysticercosis with selected neuropsychiatric disorders and/or symptoms (chronic headache, epileptic seizures/epilepsy and psychosis) in Mocuba district, Mozambique.

METHODOLOGY

Between March and May 2018, a cross-sectional study was conducted among 1,086 participants aged 2 years or above in Mocuba district, Zambézia province, central Mozambique, to assess the seroprevalence of human cysticercosis and risk factors for infection, as well as to explore its relation to selected neuropsychiatric disorders. Socio-demographic and clinical data were collected from each participant using a modified questionnaire designed by the Cysticercosis Working Group for Eastern and Southern Africa. Additionally, neuropsychiatric disorders, such as chronic headache, epileptic seizures/epilepsy and psychosis were assessed using four vignettes. T. solium antigen and cysticercosis IgG in serum were detected using both T. solium antigen B158/B60 enzyme linked immunosorbent assay (ELISA) and LDBIO Cysticercosis Western Blot, respectively.

PRINCIPAL FINDINGS

Overall, 112/1,086 participants (10.3%) were sero-positive for T. solium antigen or antibodies. Prevalence of antibodies (6.6%; n = 72) was higher than of antigens (4.9%; n = 54). In the questionnaires, 530 (49.5%) of participants reported chronic headache, 293 (27%) had generalized epileptic seizures, 188 (18%) focal seizures and 183 (18.3%) psychosis. We found a statistically significant association between seropositivity for T. solium and chronic headache (p = 0.013). Additionally, increasing age (p = 0.03) was associated with Ag-ELISA seropositivity.

CONCLUSIONS

Our study revealed that in Mocuba, T. solium cysticercosis is prevalent and associated with self-reported chronic headache. Additionally, in the study setting, the seroprevalence of cysticercosis increased with age. However, it is not associated with other neuropsychiatric disorders such epileptic seizures/epilepsy and psychosis. Future studies are needed to confirm the high burden of neuropsychiatric disorders and their possible etiology, including neurocysticercosis, using additional serological, molecular biological and radiological diagnostic tools, as well as in-depth clinical examinations.

Occurrence of Intestinal Parasites of Public Health Significance in Fresh Horticultural Products Sold in Maputo Markets and Supermarkets, Mozambique

(1) Background: Giardia duodenalis and Cryptosporidium are important neglected parasites associated with diarrhea, such as the emerging Enterocytozoon bieneusi. All three are foodborne parasites raising concerns in public health. This study intended to understand the intestinal parasite occurrence with emphasis on G. duodenalis, Cryptosporidium, and E. bieneusi in fresh fruits/vegetables sold in the main municipal markets of Maputo city, Mozambique. (2) Methods: A total of 321 fresh horticultural products were purchased in the rainy and dry seasons (five markets/two supermarkets/one agricultural zone). Light microscopy (LM) and PCR analysis were performed. (3) Results: By LM and/or PCR, 29.3% of the samples presented at least one parasite (rainy season: 22.9%; dry season: 35.1%). The most contaminated horticultural products: collected in dry season, from Zimpeto and Fajardo markets, lettuce and pointed white cabbage. Overall, 3.7% of G. duodenalis, 1.3% of E. bieneusi, and other intestinal parasites (pathogenic and non-pathogenic) were identified. (4) Conclusions: Important pathogenic intestinal parasites were identified in fruits/vegetables commercially purchased in Maputo City. This fact must be taken into consideration when planning the management of these horticultural markets, in order to reduce the risk of contamination of fresh produce by intestinal parasites, and to prevent foodborne diseases.

Molecular Detection of Soil-Transmitted Helminths and Enteric Protozoa Infection in Children and Its Association with Household Water and Sanitation in Manhiça District, Southern Mozambique

Intestinal parasite infections can have detrimental health consequences in children. In Mozambique, soil-transmitted helminth (STH) infections are controlled through mass drug administration since 2011, but no specific control program exists for enteric protozoa. This study evaluates STH and protozoan infections in children attending healthcare in Manhiça district, Southern Mozambique, and its association with water and sanitation conditions. We conducted a cross-sectional study in children between 2 and 10 years old in two health centers (n = 405). A stool sample and metadata were collected from each child. Samples were analyzed by multi-parallel real-time quantitative PCR (qPCR). We fitted logistic regression-adjusted models to assess the association between STH or protozoan infection with household water and sanitation use. Nineteen percent were infected with at least one STH and 77.5% with at least one enteric protozoon. qPCR detected 18.8% of participants with intestinal polyparasitism. Protected or unprotected water well use showed a higher risk for at least one protozoan infection in children (OR: 2.59, CI: 1.01-6.65, p-value = 0.010; OR: 5.21, CI: 1.56-17.46, p-value = 0.010, respectively) compared to household piped water. A high proportion of children had enteric protozoan infections. Well consumable water displayed high risk for that.

Assessment of Parasitic Contamination of Lettuce and Cabbages Sold in Selected Markets in Maputo City, Mozambique

Background

In Mozambique, vegetables are the main source of nutrients and they are consumed raw or cooked. Their consumption, especially in their raw form, might be a source of contamination, which may take place during production and/or transportation as well as in the markets. In this study we aimed to assess the profile and frequency of parasites in lettuces and cabbages sold in some selected markets in Maputo city, the capital of Mozambique.

Methods

A cross sectional study was conducted between February and March 2018, in 10 selected markets from Maputo City. A total of 100 combined samples of lettuces and cabbages were analyzed using a spontaneous sedimentation method. Data such as gender and age of the vendors and about handling of vegetables at the point of sale were also collected.

Results

Out of the samples, 84 (84%) were contaminated with parasites (86% of lettuces and 82% of cabbages). The analyses performed revealed the presence of E. coli (66%), S. stercoralis (40%), E. histolytica (20%), A. duodenalis (6%), S. haematobium (4%), A. lumbricoides (2%), S. mansoni (2%) and T. trichiura (1%). Two markets, Janete and Fajardo showed contamination in all samples. A Chi square analysis revealed a significant association between the contaminated cabbages and the market where they were obtained. The majority of vendors (57%) do not wash their hands before handling vegetables. Most of the vendors had tables to place vegetables (72%) and those tables are cleaned before display (86%). None of the differences observed in each risk factor studied were statistically significant.

Conclusion

The present study highlights that contamination of raw vegetables with pathogenic parasites in markets might represent a vector for transmission of intestinal and water- borne parasites to consumers. Future studies should investigate the extent of vegetable contamination at each stage of the supply chain from the farm to consumers, as well as its relationship to human parasitic infection and its consequences. Good hygienic practices of farmers, vendors and consumers should be enforced to break the contamination chain. Whenever possible, hydroponic cultivation should be encouraged to avoid the influence of highly contaminated soils.

Coinfection of HIV-1 with Schistosoma spp. and with Intestinal Parasites in Patients Attending Boane Health Center, Maputo Province, Mozambique

Background

It is hypothesized that schistosomiasis and intestinal parasites increase susceptibility to HIV-1 infection and enhance AIDS progression by immunomodulation. This study aims to compare the prevalence and risk factors for schistosomiasis and intestinal parasites in HIV-1 infected and uninfected persons and to evaluate the association between HIV-1 induced immunosuppression and risk factors for parasite infection.

Methods

This was a cross-sectional study conducted at Boane Health Center in Boane village, Maputo Province from April to June 2017 in 280 patients aged over 5 years. From each of 140 HIV-1 infected or 140 HIV-1 uninfected persons, demographic and clinical data were collected as well as one stool and urine sample for parasitological analysis. All stool samples were processed using direct wet mount and Ritchie method for detection of common parasites, and modified Ziehl-Neelsen staining techniques to identify Cryptosporidium spp., Cystoisospora belli and Cyclospora spp. oocysts from children stools. The urine was sedimented and analyzed for S. haematobium eggs detection.

Results

The overall prevalence of parasitism in the study population was 46.8% (131/280). Fifty six percent of the HIV-1 infected persons (78/140) were infected by at least one parasite compared to 38% (53/140 of the HIV-1 uninfected persons (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.2-3.3).Further, HIV-1 infected persons were more likely to be infected by S. mansoni (OR 5.6, 95% CI 1.8-15.8) when compared to HIV-1 uninfected person and HIV-1 infected women were more likely to be infected by S. mansoni (OR 6.7 CI 95% 1.8-22.8%) when compared to HIV-1 uninfected women (p< 0.001). HIV-1 serostatus (OR 7.0, 95% CI 1.5-31.2). Multivariate logistic regression revealed that HIV-1 infected status (OR=1.813575), the use of river or lake as water sources either for drinking (OR=7.289245) or domestic chores (OR=9.16205) were significant risk factor for parasitic infection. Partcipants with secondary and higher school (OR=0.379) were less likely to have a parasitic infection compared with primary school or illiterate participants.

Conclusions

It is possible that the a high prevalence of schistosomiais and intestinal parasites in this region plays an important role on the transmission and pathogenesis of HIV.

Design and Implementation of Postgraduate Programs in Health in a Resource-Limited Setting in Mozambique (The Lúrio University)

PURPOSE

To describe the strategies used to design and implement three postgraduate programs at Lúrio University (UniLúrio), a resource-limited setting, in northern Mozambique.

METHODS

We conducted a longitudinal, descriptive case study from 2011 to 2018 in two phases: 1) needs assessment (2011-2012), 2) implementation strategies (2013-2018), taking into account innovations whenever necessary.

RESULTS

Several obstacles and barriers to the establishment of postgraduate programs were identified. These included a lack of a core curricula aimed at postgraduate programs, shortage of human resources for teaching and mentorship, limited teaching and research infrastructures, limited financial resources, and lack of administrative capacity. With the support of the Medical Education Partnership Initiative (MEPI), three Master degree programs were designed and implemented. During the period of 2013-2018, UniLúrio enrolled 202 students, distributed as follows: Master degree in Tropical Medicine and Global Health (55), Master degree in Health Professional Education (99), and Master degree in Nutrition and Food Security (48). Of those, 152 (75.2%) obtained a Postgraduate Diploma as they did not present a master dissertation, 89 (44.0%) obtained their Master degree, 30 (14.8%) dropped out, and 20 (9.9%) are awaiting decision. UniLurio's staff trained a Master's degree or a Postgraduate Diploma in 34 (16.8%) and 15 (7.4%), respectively. Our strategies allowed us to improve research capacity building, and set the basis for long-term sustainability by allowing for the establishment of other postgraduate programs, and offered UniLurio a strong role in its internationalization.

CONCLUSION

By sharing multiple resources, long-lasting partnerships were established with multiple institutions, and competency-based training and postgraduate studies management were developed. Research and eLearning were leveraged, retention and faculty development was enhanced, and some inequalities within the country were reduced. These strategies and innovations can be applied to other resource-limited settings, allowing the scaleup of health professional's training and research capacity building.

Human toxoplasmosis in Mozambique: gaps in knowledge and research opportunities

Toxoplasmosis is a parasitic zoonotic disease caused by Toxoplasma gondii that afflicts humans worldwide and wild and domestic warm-blooded animals. In immunocompetent individuals, the acute phase of infection presents transient low or mild symptoms that remain unnoticed. In immunocompromised patients, T. gondii is a life-threatening opportunistic infection, which can result from the reactivation of latent infection or primary infection. Moreover, congenital toxoplasmosis, which results from the transplacental passage of tachyzoites into the fetus during a pregnant primary infection, can lead to miscarriage, stillbirth, or ocular and neurologic disease, and neurocognitive deficits in the newborns. Thus, the present review aims to address the current knowledge of T. gondii infection and toxoplasmosis in Africa and especially in Mozambique, stressing the importance of identifying risk factors and promote awareness among the health care providers and population, assessing the gaps in knowledge and define research priorities. In Mozambique, and in general in southern African countries, clinical disease and epidemiological data have not yet been entirely addressed in addition to the implications of T. gondii infection in immunocompetent individuals, in pregnant women, and its relation with neuropsychiatric disorders. The main gaps in knowledge in Mozambique include lack of awareness of the disease, lack of diagnostic methods in health facilities, lack of genetic data, and lack of control strategies.