Monitoring of Lassa virus infection in suspected and confirmed cases in Ondo State, Nigeria

Introduction: Lassa virus (LASV), the causative agent of Lassa fever (LF), an endemic acute viral haemorrhagic illness in Nigeria, is transmitted by direct contact with the rodent, contaminated food or household items. Person-to-person transmission also occurs and sexual transmission has been reported. Thus, this study investigated the presence of LASV in body fluids of suspected and confirmed cases. Methods: this was a cross-sectional study between March 2018 and April 2019 involving 112 consenting suspected and post ribavirin confirmed cases attending the Lassa fever treatment center in Ondo State. Whole blood was collected from 57 suspected and 29 confirmed cases. Other samples from confirmed cases were 5 each of High Vaginal Swab (HVS) and seminal fluid; 12 breast milk and 4 urine. All samples were analyzed using reverse transcription-PCR (RT-PCR) targeting the S-gene of LASV. Results: analysis of whole blood by RT-PCR showed that 1/57 (1.8%) suspected and 1/29 (3.4%) confirmed post ribavirin treated cases were positive. While LASV was detected in 2/5 (40%) post ribavirin treated seminal fluids and 1/11 (8.3%) breast milk. However, LASV was not detected in any of the HVS and urine samples. Conclusion: the detection of LASV in seminal fluid and breast milk of discharged post ribavirin treated cases suggests its persistence in these fluids of recovering Nigerians. The role of postnatal and sexual transmissions in the perennial outbreak of LF needs to be further evaluated

Detection of hepatitis viruses in suspected cases of Viral Haemorrhagic Fevers in Nigeria.

There have been several Viral Hemorrhagic Fever (VHF) outbreaks in Nigeria which remains a public health concern. Despite the increasing number of suspected cases of VHF due to heightened surveillance activities and growing awareness, only a few cases are laboratory-confirmed to be VHF. Routinely, these samples are only tested for Lassa virus and Yellow fever virus with occasional testing for Dengue virus when indicated. The aetiology of the disease in these VHF suspected cases in Nigeria which are negative for Lassa, Yellow fever and Dengue viruses remains a puzzle. Since the clinical features exhibited by suspected VHF cases are like other endemic illnesses such as Hepatitis, there is a need to investigate the diversity and co-infections of hepatitis viruses as differentials and possible co-morbidity in suspected cases of VHFs in Nigeria. A total of three hundred and fifty (350) blood samples of 212 (60.6%) males and 138 (39.4%) females, aged <1-70 years with a mean age of 25 ±14.5, suspected of VHFs and tested negative for Lassa, Yellow fever and Dengue viruses were investigated for Hepatitis A, B, C and E viruses at the Centre for Human and Zoonotic Virology (CHAZVY), College of Medicine, University of Lagos (CMUL) using serologic and molecular techniques. The serologic analysis of these VHF suspected cases samples revealed that 126 (36%) were positive for at least one hepatitis virus. Individual prevalence for each of the hepatitis virus screened for showed that 37 (10.6%), 18 (5.1%) and 71 (20.3%) were positive for HBV, HCV and HEV respectively. All the samples were negative for HAV. A co-infection rate of 11.9% was also observed, with HCV/HEV co-infections being the most prevalent and the Northern region having the greatest burden of infection. The evidence of hepatitis virus infections in suspected cases of VHF was documented. Thus, their associations as co-morbidities and/or mortalities in this category of individuals require further investigations in endemic countries such as Nigeria. Therefore, the possible inclusion of screening for hepatitis viruses and other aetiologic agents that could mimic infections in suspected cases of VHFs in Nigeria should be thoroughly evaluated to guide informed policy on the diagnosis and management of these cases

Saliva all positive figures.

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Age and sex distribution of study participants (n = 299).

Age and sex distribution of study participants (n = 299).</p

SARS-CoV-2 positivity by gender and sample type.

SARS-CoV-2 positivity by gender and sample type.</p

S2 File -

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Raw data and analysis.

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Fig 1 -

Cycle Threshold (Ct) values for SARS-CoV-2 positivity to (A) E-gene, (B) N-gene, and (C) Orf1ab gene respectively, show good comparison on both the Saliva and the Nasopharyngeal swab: The median Cycle Threshold (Ct) values for the three SARS-CoV-2 genes (E, N, and Orf1ab) of the positive samples (Ct 40) from both the nasopharyngeal swab and saliva samples were compared using the Wilcon signed rank exact test. The p values of 0.07715, 0.8438, and 0.2293 were determined for the E, N, and Orf1 ab genes respectively. There were no statistically significant differences between the median SARS-CoV-2 E-gene, N-gene, and Orf1ab gene Ct values detected for the Nasopharyngeal swab and Saliva samples.</p

Relationship of SARS-CoV-2 positivity with gender and age groups.

Relationship of SARS-CoV-2 positivity with gender and age groups.</p