UNLABELLEDStudy on human case of avian influenza in Guangzhou 2006 without causing human-to-human transmission

OBJECTIVETo explore the possibility of transmission from a human case of avian influenza to his close contacts.

METHODSClose contacts of the human case of avian influenza in Guangzhou 2006 were found out according to the definition and methods publicized by the Ministry of Health, People's Republic of China. Epidemiological investigation and medical observation were carried out. Serum antibodies were tested in some of the close contacts.

RESULTSThe avian influenza patient had never left Guangzhou in the month prior to disease onset. No contact history with dead or diseased poultry was found. A total of 56 close contacts, including his girl friend, relatives, friends and medical staff who had taken care of him, were brought under medical observation for 7 days but none of them showed signs of infection.

CONCLUSIONUnlike SARS, direct contact with patient contracted with avian influenza at the end of incubation period and in the stage of illness through flying droplets, saliva, mucous membrane and skin injuries will not lead to human-to-human transmission, indicating the virus' ability to pass from human to human is limited.

OBJECTIVEAn approach for analysis of HIV quasispecies using Miseq high-throughput sequencing platform (hereinafter referred to as Miseq platform) was established and applied to contact tracing for a possible case of HIV sexual transmission.

METHODSFour plasma specimens were collected from 2 HIV infections (P1 and P2) suspected to be involved in the sexual transmission and 2 local HIV infections as controls (P3 and P4). The RNAs were extracted from the specimens and then reverse-transcribed into cDNA. After HIV subtyping, Miseq platform was performed to detect and sequence the HIV quasispecies (352 bp) in each specimen. The frequency of quasispecies was counted and ranked. Intrapersonal and interpersonal genetic distance and phylogenetic tree were calculated by using the top 5, 20, 100, 500, and all quasispecies, respectively.

RESULTSThe subtypes of HIV from all 4 specimens were CRF01_AE. 23 788 to 37 397 cleaned sequences representing 1 229 to 1 412 unique HIV quasispecies were obtained from these specimens by using Miseq platform. The average genetic distance (3.5%-4.5%) between quasispecies from specimens P2 and P1 was significantly lower than that (10.3%-19.6%) between quasispecies from P2 and the controls (P3 or P4). Phylogenetic tree analysis indicated that sequences from specimens P1 and P2 clustered together while sequences from P3 and P4 exhibited completely independent clusters. When the top 20 or more quasispecies from each specimen were analyzed, sequences from P1 showed a paraphyletic relationship with those from P2, which may indicated that the direction of HIV transmission was from P1 to P2.

CONCLUSIONWith the feature of convenient and economic operation, Miseq platform has high practical value in contact tracing of possible HIV transmission.

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.
COVID-19 ; Cohort Studies ; Contact Tracing ; Humans ; Incidence ; Prospective Studies

Objective: To study the infection rate of secondary close contacts of COVID-19 patients, and assess the infection risk in the contacts. Methods: COVID-19 patients' close contacts (with a clear exposure time to index case) with negative nucleic acid test results and secondary close contacts were surveyed in continuous isolation and medical observation in this prospective study. The dynamic nucleic acid test results of the close contacts and secondary contacts of COVID-19 patients were collected to assess their risk of infection. Results: A total of 4 533 close contacts were surveyed, in whom 14 were confirmed as COVID-19 patients with overall secondary attack rate of 0.31%, and 4 201 secondary contacts were tracked, in whom no subsequent infections occurred. Conclusion: Close contacts of COVID-19 patients entered in centralized isolation for medical observation with negative nucleic acid tese results,the secondary close contacts of COVID-19 patients have no risk of infection.
COVID-19/epidemiology* ; Contact Tracing ; Humans ; Incidence ; Nucleic Acids ; Prospective Studies ; SARS-CoV-2

Beijing ; COVID-19 ; Contact Tracing ; Humans ; Risk Factors ; SARS-CoV-2

Adolescent ; Adult ; Beijing/epidemiology* ; Contact Tracing ; Female ; Humans ; Male ; Prevalence ; Tuberculosis/transmission* ; Universities ; Young Adult

The outcome of screening the household contacts of 49 newly diagnosed tuberculous children as currently practised in the Paediatric Unit of the Port Moresby General Hospital is described. The screening program generated 182 chest X-rays and 67 Mantoux tests. 32 (39%) of 83 child contacts and 11 (11%) of 99 adults were commenced on antituberculous therapy, and 2 children aged 6 months were started on INAH chemoprophylaxis. Adult contacts were identified in 11 (22%) of the 49 families screened. Such a program is an extremely important part of the case management of children with newly diagnosed tuberculosis and their families. PIP: This article describes the outcome of screening the households of 49 children diagnosed with tuberculosis (TB) in the TB section at Port Moresby General Hospital, Nigeria. Household contact screening in a group of 49 children with TB generated a total of 182 chest X-rays and 67 Mantoux tests. 32 children of the 83 screened were given full antituberculosis treatment, and 2 children aged 6 months were given INAH prophylaxis. Furthermore, 11 new adult contacts were diagnosed as new cases of TB. Of the 49 index patients, 30 children had pulmonary TB and 9 had central nervous system, 2 had bone, 2 had miliary, 1 had lymphatic, and 1 had pericardial involvement; 4 children had involvement of more than one site. Thus, the screening program is an extremely important component of the case management of children diagnosed with TB and their families.
Case Management ; Child ; Contact Tracing ; Human ; Mass Screening ; Tuberculosis - diagnosis ; Tuberculosis - epidemiology

Humans ; COVID-19/epidemiology* ; Contact Tracing ; Pandemics ; SARS-CoV-2 ; Emergency Service, Hospital

Accidental vaccinia may occur either in a recently vaccinated person through autoinoculation by veticular fluid or in a person who is in close personal contact with a recently vaccinated person. Accidental vaccinia occurs most co@mmonly on the eyelid, lips, nose or vulva. An outbreak of similar lesions in a family is unusual. We presented a case of accidental vaccinia in a 29-year old married woman. She has been relatively well until 5 days prior to visit, when she began developed painful grouped papules with central umbilication around both mammary areolas and nipples and marked painful swelling of both axillary lymphnodes. Family history revealed that her baby has also suffered from vesicopustuIar eruptions on upper lip 10 days before her onset and her nephew had similar skin eruption on left index finger for the last 1 week. Contact tracing revealed her neighboring child who was smallpox vaccinated inoculated her baby and then she was contracted from her baby, so-called, third hand vaccinia. Physical examination was not remarkable and laboratory findings were within normal limit. The biopsy finding showed findings consistent with viral infection. After symptomatic treatment and daily dressing, the akin lesion has completly healed in about 2 weeks.
Adult ; Bandages ; Biopsy ; Child ; Contact Tracing ; Eyelids ; Female ; Fingers ; Hand ; Humans ; Lip ; Nipples ; Nose ; Physical Examination ; Skin ; Smallpox ; Vaccinia* ; Vulva

OBJECTIVETo know their real epidemiological histories in 1,091 probale cases of severe acute respiratory syndrome (SARS) without definite history of contact with SARS patients in the first survey.

METHODSAll the probable SARS cases until June 9, 2003 without definite history of contact with SARS patients in the first epidemiological survey were included in a re-survey with questionnaire. The second survey was carried out during June 9 to 30, 2003.

RESULTSThe results showed that history of contact with other SARS patients was obtained in 15.9% of 1 091 probale SRAS cases in the second survey, transmission of SARS to others was found in 10.5% of them, and source of infection in hospital was found in 46.5%. Comprehensive judgement based on epidemiological history showed that probale history of contact with SARS patients could be found in 72.9% of 1,091 probale cases of SARS in the second survey.

CONCLUSIONSource of infection could be found through additional survey in part of probale cases of SARS without it in initial epidemiological survey.