Domestic risk factors for increased rodent abundance in a Lassa fever endemic region of rural Upper Guinea

Lassa fever (LF) is a viral haemorrhagic fever endemic in West Africa and spread primarily by the multimammate rat, Mastomys natalensis. As there is no vaccine, reduction of rodent-human transmission is essential for disease control. As the household is thought to be a key site of transmission, understanding domestic risk factors for M. natalensis abundance is crucial. Rodent captures in conjunction with domestic surveys were carried out in 6 villages in an area of rural Upper Guinea with high LF endemicity. 120 rodent traps were set in rooms along a transect in each village for three nights, and the survey was administered in each household on the transects. This study was able to detect several domestic risk factors for increased rodent abundance in rural Upper Guinea. Regression analysis demonstrated that having > 8 holes (RR = 1.8 [1.0004-3.2, p = 0.048), the presence of rodent burrows (RR = 2.3 [1.6-3.23, p = 0.000003), and being in a multi-room square building (RR = 2.0 [1.3-2.9], p = 0.001) were associated with increased rodent abundance. The most addressable of these may be rodent burrows, as burrow patching is a relatively simple process that may reduce rodent entry. Further study is warranted to explicitly link domestic rodent abundance to LF risk, to better characterize domestic risk factors, and to evaluate how household rodent-proofing interventions could contribute to LF control

Cryptococcal meningitis associated HIV infection in the Donka national hospital in Conakry (Guinea)

Background Cryptococcal meningitis (CM) is an infection of the brain parenchyma and subarachnoid space by the encapsulated saprophyte yeast organisms such as Cryptococcus neoformans. Over the last twenty years, HIV has created a large and severely immune compromisized population in whom C. neoformans is a dangerous opportunistic infection. In Guinea, the prevalence of CM is unknown. We hypothesized that the occurrence of CM correlates with AIDS/ HIV prevalence.Method This retrospective observational study was carried out at the national Hospital of Conakry (Guinea) between 2001 and 2002. We describe here the epidemiological and clinical and biological characteristics of CM disease in our national hospital.Results Our data show that, 28.6 % of HIV patients with neurological symptoms had Cryptococcus neoformans in their CSF by using Indian ink staining. The median age was 36±3 years and sex ratio (M/F) was 1.8. The major complaints were fever and cephalgia, giddiness while the major complications were altered consciousness and hemiplegia. CSF was clear with low level of glucose and higher level of albumin. The means of lymphocytes in CSF was 8±2/mm3.Conclusion This data therefore becomes relevant in not only focusing of neurological symptoms associated with HIV to be toxoplasmosis but the possibility of C neoformans in these patients; particularly when they present symptoms such as headaches, giddiness and sniff neck etc. This can easily be carried out with Indian ink staining technique

Resurgence of Ebola virus in 2021 in Guinea suggests a new paradigm for outbreaks

These authors contributed equally: Alpha K. Keita, Fara R. Koundouno, Martin Faye, Ariane Düx, Julia Hinzmann.International audienc

The Status of Humoral Immunity to Parvovirus B19 in Population of Certain Geographical Regions

Introduction. In a number of countries, including Russia, there is no systematic registration and reporting of parvovirus infection cases; the extent of its spread can be estimated by using humoral immunity rates.Purpose of the study: Assessment of seroprevalence of parvovirus B19 (B19V) in different age groups of population of Russia, Central Asia, and West Africa.Materials and methods. A total of 1,732 blood serum samples from residents of St. Petersburg and Nur-Sultan, migrant workers from Uzbekistan and Tajikistan, residents of the Republic of Guinea were studied for IgG antibodies to B19V.Results. The highest seroprevalence rates were identified in St. Petersburg and Nur-Sultan (62–65%); the lowest rates were registered among migrant workers from Uzbekistan and Tajikistan (47%). The results for the Republic of Guinea showed a B19V seroprevalence rate of 53%. It was found that there is an increasing trend of seropositivity with age; the percentage of seropositive individuals clearly increases in older age groups: up to 55% — among migrant workers from Central Asia and residents of the Republic of Guinea; up to 80–85% — among residents of St. Petersburg and Nur-Sultan.Discussion. The obtained results confirm the worldwide occurrence of parvovirus infection. People susceptible to infection can cause infection spreading in high-risk groups — among pregnant women, immunodeficient patients, blood product recipients, and cancer patients

New Hosts of The Lassa Virus.

Lassa virus (LASV) causes a deadly haemorrhagic fever in humans, killing several thousand people in West Africa annually. For 40 years, the Natal multimammate rat, Mastomys natalensis, has been assumed to be the sole host of LASV. We found evidence that LASV is also hosted by other rodent species: the African wood mouse Hylomyscus pamfi in Nigeria, and the Guinea multimammate mouse Mastomys erythroleucus in both Nigeria and Guinea. Virus strains from these animals were isolated in the BSL-4 laboratory and fully sequenced. Phylogenetic analyses of viral genes coding for glycoprotein, nucleoprotein, polymerase and matrix protein show that Lassa strains detected in M. erythroleucus belong to lineages III and IV. The strain from H. pamfi clusters close to lineage I (for S gene) and between II &III (for L gene). Discovery of new rodent hosts has implications for LASV evolution and its spread into new areas within West Africa

Serological evidence of zoonotic filovirus exposure among bushmeat hunters in Guinea

Human Ebola virus (EBOV) outbreaks caused by persistent EBOV infection raises questions on the role of zoonotic spillover in filovirus epidemiology. To characterise filovirus zoonotic exposure, we collected cross-sectional serum samples from bushmeat hunters (n = 498) in Macenta Prefecture Guinea, adjacent to the index site of the 2013 EBOV-Makona spillover event. We identified distinct immune signatures (20/498, 4.0%) to multiple EBOV antigens (GP, NP, VP40) using stepwise ELISA and Western blot analysis and, live EBOV neutralisation (5/20; 25%). Using comparative serological data from PCR-confirmed survivors of the 2013-2016 EBOV outbreak, we demonstrated that most signatures (15/20) were not plausibly explained by prior EBOV-Makona exposure. Subsequent data-driven modelling of EBOV immunological outcomes to remote-sensing environmental data also revealed consistent associations with intact closed canopy forest. Together our findings suggest exposure to other closely related filoviruses prior to the 2013-2016 West Africa epidemic and highlight future surveillance priorities