Seroprevalence study of Toscana virus in Yafran area, Libya.

BACKGROUND & OBJECTIVES: In Mediterranean countries, infection of Toscana virus is a public health problem during the summer season, related to sandflies activity; it may cause aseptic meningitis and mild meningoencephalitis. We investigated the presence of antibodies (IgG) against the Toscana virus in the sera of individuals living in the area of Yafran, Libya. METHODS: During the period from December 2013 to February 2014, a total of 232 sera samples were collected from Yefran hospital. Demographic information of participants collected in a questionnaire; samples were analyzed by the serological method of enzyme-linked immunoassays specific for Toscana IgG antibodies. RESULTS: Seroprevalence of IgG antibodies among samples was 25% (n = 232). Seroprevalence varied among genders, age groups. The differences were not statically significant. INTERPRETATION & CONCLUSION: Our findings indicate and confirm local circulation of the Toscana virus. It also indicates that TOSV infection is neglected, and needs to be considered as one of the causes of meningitis or meningoencephalitis.

Prevalence of IgG antibodies for the West Nile virus in human population in Tripoli, Libya.

BACKGROUND & OBJECTIVES: West Nile fever (WNF) is a mosquito-borne viral infection, circulated in natural cycles between birds and mosquitoes, particularly Culex species. It is transmitted to humans through mosquito bites, and causes a variety of clinical outcomes, ranging from asymptomatic or mild febrile illness to severe men in go encepha- litis with some fatalities observed in older or immunocompromised patients. West Nile virus (WNV) transmission is considerably influenced by environmental conditions; and abundance of avifauna and mosquitoes.There are very few reports on WNV exposure in individuals from Tripoli City in Libya. The main objective was to provide basic epidemiological information about the WNV seroprevalence in the human population of Tripoli. METHODS: A total of 400 serum samples were collected from persons (123 females, 277 males; age range: 15-78 yr) approaching the Tripoli Reference Laboratory for the purpose of obtaining health certificate; during the period from August to October 2013. The presence of WNV IgG antibodies was evaluated by a commercial kit based on WNV immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA). RESULTS: It was observed that 2.75% (11/400) samples were found reactive in the WNV ELISA assay. This result suggests that WNV has a low prevalence in the study area. INTERPRETATION & CONCLUSION: Seropositivity rates of WNV in Tripoli region of Libya were low. However, continu- ous monitoring of population is important to keep track of the disease prevalence, risk factors, reservoir hosts and vectors for better understaning of the disease epidemiology and designing appropriate control strategies.

Plague outbreak in Libya, 2009, unrelated to plague in Algeria.

After 25 years of no cases of plague, this disease recurred near Tobruk, Libya, in 2009. An epidemiologic investigation identified 5 confirmed cases. We determined ribotypes, Not1 restriction profiles, and IS100 and IS1541 hybridization patterns of strains isolated during this outbreak. We also analyzed strains isolated during the 2003 plague epidemic in Algeria to determine whether there were epidemiologic links between the 2 events. Our results demonstrate unambiguously that neighboring but independent plague foci coexist in Algeria and Libya. They also indicate that these outbreaks were most likely caused by reactivation of organisms in local or regional foci believed to be dormant (Libya) or extinct (Algeria) for decades, rather than by recent importation of Yersinia pestis from distant foci. Environmental factors favorable for plague reemergence might exist in this area and lead to reactivation of organisms in other ancient foci.

Hospitalization among vaccines for SARS-CoV-2 breakthrough infection after dose sparing strategies in Libya: A cohort study.

SARS-CoV-2 infection is widely spread over people, from youth to the elderly. Vaccination against SARS-CoV-2 is an essential preventive measure to help end the SARS-CoV-2 pandemic. A multi-center retrospective cohort study was conducted on patients in Libya who had received single-dose licensed three different types of vaccines (Oxford/AstraZeneca, CoronaVac, or Sputnik-V) and were admitted to healthcare centers with SARS-CoV-2 infection from 30th April to 15th July 2021. In this study, the number of people infected with SARS-COV-2 and the mortality rate from daily reports issued by the National Centers for Disease Control of Libya (NCDC) were collected. Approximately 445000 single doses of the SARS-COV-2 vaccine were administered in Libya from April to July 2021. In corresponding, 39996 people were infected during this period. It has been found that among the people who did not receive any vaccine, the number of patients infected by SARS-COV-2 and admitted to the healthcare centers, and died was (N = 3176 patients (7.94%), and 266 (7.10%) respectively). Compared to 43 (0.10%) of those admitted to healthcare centers who had taken a single dose from one of the licensed vaccines, of which 8 patients (0.02%) died during this period. The documented 23 patients were those who admitted to healthcare centers and got vaccinated with the CoronaVac (Sinovac) vaccine. Fourteen patients received Oxford/AstraZeneca. Only 2 patients received the Sputnik V vaccine. Of the breakthrough infection cases reviewed, 8 patients died. No deaths due to breakthrough infection among Sputnik V vaccinated patients were reported. In conclusion, a single dose of the three different types of the vaccine has significantly reduced virus interpersonal transmission and also showed a decrease in the mortality rate until the tenth week in Libya. The present study demonstrates the extent of the remarkable success of the early rollout of the coronavirus national vaccination campaign.

Exploiting epidemiological data to understand the epidemiology and factors that influence COVID-19 pandemic in Libya.

There were only 75 confirmed cases of coronavirus disease 2019 (COVID-19) reported in Libya by the National Center for Disease Control during the first two months following the first confirmed case on 24 March 2020. However, there was dramatic increase in positive cases from June to now; as of 19 November 2020, approximately 357940 samples have been tested by reverse transcription polymerase chain reaction, and the results have revealed a total number of 76808 confirmed cases, 47587 recovered cases and 1068 deaths. The case fatality ratio was estimated to be 1.40%, and the mortality rate was estimated to be 15.90 in 100000 people. The epidemiological situation markedly changed from mid-July to the beginning of August, and the country proceeded to the cluster phase. COVID-19 has spread in almost all Libyan cities, and this reflects the high transmission rate of the virus at the regional level with the highest positivity rates, at an average of 14.54%. Apparently, there is an underestimation of the actual number of COVID-19 cases due to the low testing capacity. Consequently, the Libyan health authority needs to initiate a large-scale case-screening process and enforce testing capacities and contact testing within the time frame, which is not an easy task. Advisably, the Libyan health authority should improve the public health capacities and conduct strict hygienic measures among the societies and vaccinate as many people against COVID-19 to minimize both the case fatality ratio and socio-economic impacts of the pandemic in Libya.

A human case of urogenital myiasis caused by Psychoda sp. larvae in Tripoli, Libya

Urogenital myiasis caused by Psychoda spp. involving human are very rare and present with unusual symptoms. Larvae belonging to Psychoda sp. (Diptera: Psychodidae) were found in the urogenital tract of a 9-year-old girl, who lives in Tajoura, Libya, and had suffered from genital pruritus and moving larvae in urine. This is the first record of such case in Libya.

Field Evaluation of Outdoor Ultra-Low Volume (ULV) Applications against Phlebotomine Sand Flies (Diptera: Psychodidae) in Al Rabta, North-West of Libya.

BACKGROUND: Al Rabta is a rural area in the North-West of Libya that represents an important focus of zoonotic cutaneous leishmaniasis. This study aimed to evaluate the effect of Ultra Low Volume (ULV) applications in controlling sand flies and its impact on leishmaniasis transmission in this area. METHODS: Two neighboring villages were selected: Al Rabta West (RW) as cypermethrin treated village and Al Rabta East (RE) as check one. The ULV was evaluated through 3 spraying cycles during Apr, Jun and Sep 2013. In the two villages, a number of outdoor sites were selected for sampling of sand flies (twice a month) using the CDC light traps. The cases of CL reported in the two villages during the study period were obtained from Al Rabta health center. RESULTS: The two villages were similar where 9 species of sand flies (6 of Phlebotomu and 3 of Sergentomyia) were collected of which S. minuta and P. papatasi were the abundant species. As compared to the pre- ULV spraying, during the post- spraying periods: i) the reduction in abundance of the different species ranged from 20.85 to 77.52% with 46.69% as an overall reduction for all species altogether and, ii) in significantly (P> 0.05) higher mean ratio of males: females for all species altogether (1:2.41). Moreover, ULV spraying resulted in the absence of CL (Leishmania major) cases (Passive Case Detection). CONCLUSION: The efficiency of ULV spraying in reducing sand fly population, CL cases and consequently limits the disease transmission.

Coarse-resolution Ecology of Etiological Agent, Vector, and Reservoirs of Zoonotic Cutaneous Leishmaniasis in Libya.

Cutaneous leishmaniasis ranks among the tropical diseases least known and most neglected in Libya. World Health Organization reports recognized associations of Phlebotomus papatasi, Psammomys obesus, and Meriones spp., with transmission of zoonotic cutaneous leishmaniasis (ZCL; caused by Leishmania major) across Libya. Here, we map risk of ZCL infection based on occurrence records of L. major, P. papatasi, and four potential animal reservoirs (Meriones libycus, Meriones shawi, Psammomys obesus, and Gerbillus gerbillus). Ecological niche models identified limited risk areas for ZCL across the northern coast of the country; most species associated with ZCL transmission were confined to this same region, but some had ranges extending to central Libya. All ENM predictions were significant based on partial ROC tests. As a further evaluation of L. major ENM predictions, we compared predictions with 98 additional independent records provided by the Libyan National Centre for Disease Control (NCDC); all of these records fell inside the belt predicted as suitable for ZCL. We tested ecological niche similarity among vector, parasite, and reservoir species and could not reject any null hypotheses of niche similarity. Finally, we tested among possible combinations of vector and reservoir that could predict all recent human ZCL cases reported by NCDC; only three combinations could anticipate the distribution of human cases across the country.

Entomological studies of phlebotomine sand flies (Diptera: Psychodidae) in relation to cutaneous leishmaniasis transmission in Al Rabta, North West of Libya.

Al Rabta in the North-West of Libya is a rural area where cutaneous leishmaniasis (CL) is endemic for long time. Few reports are available on sand flies in this area which is an important focus of CL. Therefore, this study aimed at updating the species composition, and monthly fluctuation of sand flies in this area. Sand flies were biweekly collected by CDC light traps from June to November 2012 and April to November 2013 in two villages, Al Rabta East (RE) and Al Rabta West (RW). Nine species (6 Phlebotomus and 3 Sergentomyia) were reported in the two villages. A total of 5605 and 5446 flies were collected of which Phlebotomus represented 59.30 and 56.63% in RE and RW, respectively. Sergentomyia minuta and Phlebotomus papatasi were the abundant species. Generally, more males were collected than females for all species. The overall ratios (males: females) for most of species were not deviated from the expected 1:1 ratio (Chi-squared, P>0.05). Sand fly abundance (fly/trap) is directly related to the temperature and RH (P<0. 01) while it inversely related to wind velocity (P>0.05). Flies were active from April to November with increased activity from June to October. Prominent peaks were in September and June. The abundance of P. papatasi and Phlebotomus sergenti, vectors of CL (August-October) coincided with the reported higher numbers of CL cases (August- November). The obtained results could be important for the successful planning and implementation of leishmaniasis control programs.

First molecular epidemiological study of cutaneous leishmaniasis in Libya.

BACKGROUND: Cutaneous leishmaniasis (CL) is a major public health problem in Libya. The objective of this study was to investigate, for the first time, epidemiological features of CL outbreaks in Libya including molecular identification of parasites, the geographical distribution of cases and possible scenarios of parasite transmission. METHODOLOGY/PRINCIPAL FINDINGS: We studied 450 patients that came from 49 areas distributed in 12 districts in north-west Libya. The patients' ages ranged from 9 months to 87 years (median age 25 years); 54% of the cases were males. Skin scrapings spotted on glass slides were collected for molecular identification of causative agent. The ribosomal internal transcribed spacer 1 (ITS1) was amplified and subsequently characterized by restriction fragment length polymorphism (RFLP) analysis. In total, 195 samples were successfully identified of which 148 (75.9%) were Leishmania major, and 47 (24.1%) Leishmania tropica. CL cases infected with L. major were found in all CL areas whereas L. tropica cases came mainly from Al Jabal Al Gharbi (46.4%), Misrata (17.8%) and Tarhuna districts (10.7%). A trend of seasonality was noticed for the infections with L. major which showed a clear peak between November and January, but was less pronounced for infections by L. tropica. CONCLUSION: The first molecular study on CL in Libya revealed that the disease is caused by L. major and L. tropica and the epidemiological patterns in the different foci were the same as in other Mediterranean foci of CL.