Cryptosporidium Infections in Africa—How Important Is Zoonotic Transmission? A Review of the Evidence

Cryptosporidium, a protozoan parasite in the phylum Apicomplexa, is the etiological agent of cryptosporidiosis, an intestinal infection characterized by profuse watery diarrhea. Over 30 species of Cryptosporidium are recognized, some host specific whereas others infect a broader host range. Cryptosporidium hominis and Cryptosporidium parvum are the species most commonly associated with human infection; C. hominis is largely associated only with human infections, but C. parvum is also associated with infection in animals, especially young ruminants. In some regions, cryptosporidiosis is a serious veterinary problem, particularly for calves, and lambs. Many outbreaks of human cryptosporidiosis have been associated with zoonotic transmission following contact with infected animals. In Africa, where cryptosporidiosis is a major contributor to pediatric morbidity and mortality, evidence suggests transmission is principally anthroponotic. Given the frequent close contact between humans and animals in Africa, the apparent predominance of human-to-human transmission is both interesting and puzzling. In this article, after a brief “text book” introduction to the parasite, we consider in separate sections the different aspects of relevance to Cryptosporidium transmission in African countries, describing different aspects of the various species and subtypes in human and animal infections, considering livestock management practices in different African countries, and looking for any characteristic “hot spots” where zoonotic transmission has apparently occurred. Studies where transmission networks have been investigated are particularly relevant. Finally, in a separate section, we try to gather these different strands of evidence together in order to assess the reasons behind the apparent predominance of anthroponotic transmission in Africa. Reviewing the available evidence provides an opportunity to re-think transmission pathways, not only in Africa but also elsewhere, and also to pose questions. Does the predominance of human-to-human transmission in Africa reflect a relative absence of zoonotic C. parvum in African livestock? Are Africans less susceptible to zoonotic Cryptosporidium infection, perhaps resulting from early immunostimulation by C. hominis or due to inherent genetic traits? Is the African environment—in all its variety—simply more detrimental to oocyst survival? Will the so-called hypertransmissible subtypes, currently relatively rare in Africa, be introduced from Europe or elsewhere, and, if so, will they fade out or establish and spread? Our intention with this manuscript is not only to summarize and consolidate diverse data, thereby providing an overview of data gaps, but also to provide food for thought regarding transmission of a parasite that continues to have a considerable impact on both human and animal health.publishedVersio

SURVEILLANCE FOR VANCOMYCIN RESISTANT ENTEROCOCCI IN A TERTIARY INSTITUTION IN SOUTH WESTERN NIGERIA

Background. Enterococci are responsible for up to 12% of cases of healthcare associated infections worldwide and cause life threatening infections among critically ill patients. They show intrinsic and acquired resistance to a wide range of antimicrobial agents. Glycopeptide resistance is due to vanA, vanB, vanC, vanD, vanE, vanG and vanL genes. Objectives. To determine the carriage rate of VRE among patients on prolonged hospitalization in LUTH, assess the antimicrobial resistance pattern of VRE, identify factors associated with VRE colonization and describe the genetic determinants of enterococcal resistance to Vancomycin. Methods. VRE were isolated from rectal swabs collected from patients hospitalized for seven days or more in Lagos University Teaching Hospital and identified by Matrix Assisted Laser Desorption Ionization (MALDI) and Polymerase Chain Reaction (PCR). Antimicrobial susceptibility testing was performed by E-test. PCR assay for Vancomycin resistance genes was also performed. Data on demographic and risk factors collected by questionnaire was tested for significance using chi square. Results. Thirteen of 319 patients surveyed were colonized with VRE; one with vanA E. faecium, two with vanB E. faecium, ten with E. gallinarum and one with E. casseliflavus. Univariate analysis for risk factors associated with VRE colonization was only significant for the ward of admission. Only one VRE isolate showed full resistance to vancomycin and Teicoplanin. Three were resistant to Ampicillin and nine to Ciprofloxacin but all were susceptible to Linezolid. High-level resistance to Gentamicin was found in four VRE isolates. Conclusion. There is a low prevalence of VRE in Lagos University Teaching Hospital which may be spreading among patients in affected wards

Proportion of medical doctors scoring a high knowledge score in the questionnaire surveying knowledge on toxoplasmosis in Nigeria, by their background information.

<p>Proportion of medical doctors scoring a high knowledge score in the questionnaire surveying knowledge on toxoplasmosis in Nigeria, by their background information.</p

Distribution of answers of medical doctors to the knowledge questions on toxoplasmosis.

<p>The seventeen answers that were considered correct are highlighted with bold font.</p

Multivariable logistic regression model for predicting having seen a case of clinical toxoplasmosis among medical doctors in Nigeria.

<p>Multivariable logistic regression model for predicting having seen a case of clinical toxoplasmosis among medical doctors in Nigeria.</p

Cryptosporidium Infections in Africa—How Important Is Zoonotic Transmission? A Review of the Evidence

Cryptosporidium, a protozoan parasite in the phylum Apicomplexa, is the etiological agent of cryptosporidiosis, an intestinal infection characterized by profuse watery diarrhea. Over 30 species of Cryptosporidium are recognized, some host specific whereas others infect a broader host range. Cryptosporidium hominis and Cryptosporidium parvum are the species most commonly associated with human infection; C. hominis is largely associated only with human infections, but C. parvum is also associated with infection in animals, especially young ruminants. In some regions, cryptosporidiosis is a serious veterinary problem, particularly for calves, and lambs. Many outbreaks of human cryptosporidiosis have been associated with zoonotic transmission following contact with infected animals. In Africa, where cryptosporidiosis is a major contributor to pediatric morbidity and mortality, evidence suggests transmission is principally anthroponotic. Given the frequent close contact between humans and animals in Africa, the apparent predominance of human-to-human transmission is both interesting and puzzling. In this article, after a brief “text book” introduction to the parasite, we consider in separate sections the different aspects of relevance to Cryptosporidium transmission in African countries, describing different aspects of the various species and subtypes in human and animal infections, considering livestock management practices in different African countries, and looking for any characteristic “hot spots” where zoonotic transmission has apparently occurred. Studies where transmission networks have been investigated are particularly relevant. Finally, in a separate section, we try to gather these different strands of evidence together in order to assess the reasons behind the apparent predominance of anthroponotic transmission in Africa. Reviewing the available evidence provides an opportunity to re-think transmission pathways, not only in Africa but also elsewhere, and also to pose questions. Does the predominance of human-to-human transmission in Africa reflect a relative absence of zoonotic C. parvum in African livestock? Are Africans less susceptible to zoonotic Cryptosporidium infection, perhaps resulting from early immunostimulation by C. hominis or due to inherent genetic traits? Is the African environment—in all its variety—simply more detrimental to oocyst survival? Will the so-called hypertransmissible subtypes, currently relatively rare in Africa, be introduced from Europe or elsewhere, and, if so, will they fade out or establish and spread? Our intention with this manuscript is not only to summarize and consolidate diverse data, thereby providing an overview of data gaps, but also to provide food for thought regarding transmission of a parasite that continues to have a considerable impact on both human and animal health

Epidemiological Study of the Association Between Malaria and Helminth Infections in Nigeria

The relationship between intestinal helminth infection and susceptibility to malaria remains unclear. We studied the relationship between these infections. Seven schools in Ilero, Nigeria referred all pupils with febrile illness to our study center for free malaria treatment during a 3-month study period. At the end, all pupils submitted a stool sample for microscopic investigation for helminth eggs. We used an unmatched case-control design to calculate the odds ratios for helminth infection in children with at least one attack of malaria (cases) and children with no malaria episodes during the study (controls). We recorded 115 malaria cases in 82 of 354 (23.2%), 16 of 736 (2.2%), and 17 of 348 (4.7%) children ages ≤ 5, 6–10, and 11–15 years old, respectively (P = 0.001). Helminth infection rate in cases was 21 of 115 (18.3%) compared with 456 of 1,327 (34.4%) in controls. Weighted odds ratio stratified by age group for helminth infection in cases versus controls was 0.50 (95% confidence interval = 0.2–0.84, P < 0.01). Ascaris and hookworm were the most common helminths detected, with prevalence rates of 14 (12.2%) and 6 (5.2%) among cases compared with 333 (25.1%) and 132 (10.0%) in controls, respectively (P = 0.001). The negative association between helminth infection and malaria may be of importance in the design of deworming programs

Cryptosporidium Infections in Africa—How Important Is Zoonotic Transmission? A Review of the Evidence

Cryptosporidium, a protozoan parasite in the phylum Apicomplexa, is the etiological agent of cryptosporidiosis, an intestinal infection characterized by profuse watery diarrhea. Over 30 species of Cryptosporidium are recognized, some host specific whereas others infect a broader host range. Cryptosporidium hominis and Cryptosporidium parvum are the species most commonly associated with human infection; C. hominis is largely associated only with human infections, but C. parvum is also associated with infection in animals, especially young ruminants. In some regions, cryptosporidiosis is a serious veterinary problem, particularly for calves, and lambs. Many outbreaks of human cryptosporidiosis have been associated with zoonotic transmission following contact with infected animals. In Africa, where cryptosporidiosis is a major contributor to pediatric morbidity and mortality, evidence suggests transmission is principally anthroponotic. Given the frequent close contact between humans and animals in Africa, the apparent predominance of human-to-human transmission is both interesting and puzzling. In this article, after a brief “text book” introduction to the parasite, we consider in separate sections the different aspects of relevance to Cryptosporidium transmission in African countries, describing different aspects of the various species and subtypes in human and animal infections, considering livestock management practices in different African countries, and looking for any characteristic “hot spots” where zoonotic transmission has apparently occurred. Studies where transmission networks have been investigated are particularly relevant. Finally, in a separate section, we try to gather these different strands of evidence together in order to assess the reasons behind the apparent predominance of anthroponotic transmission in Africa. Reviewing the available evidence provides an opportunity to re-think transmission pathways, not only in Africa but also elsewhere, and also to pose questions. Does the predominance of human-to-human transmission in Africa reflect a relative absence of zoonotic C. parvum in African livestock? Are Africans less susceptible to zoonotic Cryptosporidium infection, perhaps resulting from early immunostimulation by C. hominis or due to inherent genetic traits? Is the African environment—in all its variety—simply more detrimental to oocyst survival? Will the so-called hypertransmissible subtypes, currently relatively rare in Africa, be introduced from Europe or elsewhere, and, if so, will they fade out or establish and spread? Our intention with this manuscript is not only to summarize and consolidate diverse data, thereby providing an overview of data gaps, but also to provide food for thought regarding transmission of a parasite that continues to have a considerable impact on both human and animal health

Toxoplasmosis - Awareness and knowledge among medical doctors in Nigeria

Toxoplasma gondii is a zoonotic parasite causing high disease burden worldwide. A One Health approach is needed to understand, prevent, and control toxoplasmosis, while knowledge gaps in the One Health aspects have been identified among medical professionals in earlier studies. As a One Health collaboration between veterinary and medical fields, we surveyed the knowledge on toxoplasmosis among medical doctors in Nigeria. The knowledge questions, which the participants answered without consulting literature and colleagues, covered epidemiological One Health aspects as well as clinical interspecialty aspects of T. gondii infections. Altogether 522 medical doctors from four tertiary hospitals completed the questionnaire. The mean number of correct answers in the knowledge questions was 7.5, and 8.4% of the participants selected at least 12 of the 17 correct answers. The proportion of medical doctors scoring such a high score was significantly higher among those who reported having seen a case of clinical toxoplasmosis than in those who did not. While 62% of the medical doctors participating in our study knew that cats can shed T. gondii in their feces, 36% incorrectly suggested that humans could do that too. That T. gondii infection can be meatborne was known by 69%, but that it can be also waterborne only by 28% of the medical doctors participating in our study. Most of the medical doctors, 78%, knew that clinical toxoplasmosis may involve the central nervous system, while only 37% answered that it can involve the eyes. Our results suggested knowledge gaps, which need to be addressed in Continuous Medical Education. The identified gaps included both intersectoral One Health aspects and interspecialty aspects: For prevention and management of toxoplasmosis, knowing the main transmission routes and that the parasite can affect several organs is relevant.Peer reviewe